Technical Field

This specification describes example sensing systems and methods for vehicles and for vehicle suspension systems.

Background of the Related Art

In the United States, the Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. Construction of the Interstate Highway System was authorized by the Federal Aid

Highway Act of 1956. The Interstate Highway System extends throughout the contiguous United States and has routes in Hawaii, Alaska, and Puerto Rico.

With great roads, trucking is an essential component of the economy infrastructure.

Indeed, a tractor-trailer vehicle cruising down the Interstate Highway is common. Trucking is involved in the delivery of not only almost every consumer product but industrial products as well. Truck drivers are often independent drivers who may or may not own their own trailer but, in any case, contract to deliver one or more full-load or part-load trailers. Indeed, being a truck driver is one of the most common jobs in America.

A paradigm shift is on the horizon as the asphalt highway is integrated into the information age. Such vehicles will be equipped with a suite of technology to connect to the information superhighway and image the physical superhighway. The vehicles will form a virtual image of the road that is processed for navigation and control. The technology will include cameras, LIDAR, RADAR, sensors of all sorts, motors and of course a large processing capacity (e.g., processors, memory, power supplies etc.).

Problems with transport by tractor-trailer vehicle remain despite the longstanding and ubiquitous use. Mobile vehicles have been slow to beneficially utilize the potential benefits of interconnection and analysis. Other obstacles stem from the typical driver not being comfortable navigating use of sophisticated electronics or various configurations that are simply not interoperable. Further, without drivers, many more tasks and maintenance activities must be automated. Thus, a need exists for easy, automatic connection and operation of vehicles with more sophisticated communication and networking technology on vehicles, particularly tractor- trailer vehicles.

Still further obstacles remain in that innovative hardware to solve longstanding problems has not yet been invented to solve such problems. For example, drivers may have to forage through large lots of trailers to find the desired trailer. In view of this, there is a need for hardware and a method to quickly and easily help the driver locate and connect to the desired trailer.

Large-scale tractor-trailer vehicles are designed to support heavy loads. In a tractor- trailer vehicles for example, freight is contained in a cargo area. The weight of the freight is distributed to a chassis of the vehicle. The weight and its distribution may affect operation of the vehicle so that monitoring the status of the suspension system and other components can provide valuable information, increase safety and improve overall performance and reliability.

SUMMARY

In view of the above, the present disclosure is directed to systems and methods for establishing a vehicle area network on a vehicle having a tractor with a tractor wireless hub, the tractor being connected to a first trailer having a first trailer wireless hub. The subject technology includes the steps of: activating the tractor hub and the first trailer wireless hub; and sharing credentials between the tractor wireless hub and the first trailer wireless hub in accordance with out of band pairing techniques. The first trailer wireless hub can be activated by a power line connection being made between the tractor and the first trailer, with the credentials shared via the power line connection.

In one embodiment, the tractor wireless hub is activated by a key fob being in proximity to the tractor, or the driver pressing a button on the key fob and the like. The vehicle area network components may also be activated any time the tractor is running. When not running, the vehicle area network may be in sleep mode where the vehicle area network components only periodically check for activity that would prompt activation.

A pairing device can establish communication between the tractor wireless hub and a plurality of sensors on the tractor. Transmitter/receivers act as range extenders for relaying signals from the plurality of sensors to the tractor wireless hub. The vehicle area network including a tractor subnetwork based on the tractor wireless hub and a first trailer subnetwork based on the first trailer wireless hub, wherein the tractor wireless hub acts as an access point for the vehicle area network.

A second trailer can also be coupled to the first trailer, wherein the second trailer has a second trailer wireless hub that is activated upon a power line connection being made between the first and second trailers. With the additional trailer, the access point can be centralized by: searching down a length of the vehicle to determine relative locations of the tractor wireless hub, the first trailer wireless hub and the second trailer wireless hub; determining a centrally located hub based on the locations; and establishing the centrally located hub as the access point. The method can also establish communication between the tractor wireless hub and a telematics device as well as communication between a plurality of sensors throughout the vehicle. By processing data from the plurality of sensors, proper action for the vehicle can be determined, whether the action be taken automatically in an autonomous vehicle, by the driver and/or by service personnel. Examples of possible proper action are: displaying a warning on a dashboard in the tractor; changing a tire; modifying an autonomous control of the vehicle;

scheduling a maintenance appointment; and the like.

Still another embodiment of the present disclosure includes a method for automatically recognizing an order of a first and second trailer on a tractor to form a vehicle, the method comprising the steps of: creating a vehicle area network including a first subnetwork on the first trailer, a second subnetwork on the second trailer, and a wireless hub on the tractor and in communication with each subnetwork; capturing, by the wireless hub, a received signal strength indicators (RSSI) and a time of flight (ToF) from each subnetwork to form a set of data;

determining a highest RSSI and lowest ToF in the set; and if the highest RSSI and the lowest ToF are from the first subnetwork, identifying the first trailer as being immediately adjacent the tractor.

The method can also include identifying the second trailer as being behind the first trailer if the highest RSSI and the lowest ToF are from the first subnetwork and no other subnetworks are present. When the vehicle includes a third trailer with a third subnetwork, the method can capturing, by the wireless hub, a RSSI and ToF from the third subnetwork and add the third subnetwork RSSI and ToF to the set of data. To further determine trailer order, the method determines a second highest RSSI and second lowest ToF in the set. If the second highest RSSI and the second lowest ToF are from the second subnetwork, identifying the second trailer as between the first trailer and the third trailer.

And yet another embodiment of the present invention includes a method for locating a trailer for a tractor-trailer vehicle by providing a beacon on the trailer that transmits a signal wirelessly to an external network. The beacon signal includes global positioning system (GPS) data indicating a location of the trailer so that the GPS data is sent from the external network to a tractor for use by the tractor. The display may include driving directions for review by the driver or execution by an autonomous vehicle. In one embodiment, the beacon includes a LED light that is activated when the tractor is within communication range of a communication hub on the tractor. Once the trailer is located, the method automatically pairs the communication hub with a subnetwork on the trailer to form a vehicle area network.

The subject technology is also directed to a tractor-trailer vehicle including a tractor that having at least four tires, two of which can be turned to steer a direction of travel of the tractor.

A first wireless hub is integrated with the tractor and a trailer is removably connected to the tractor. The trailer has a front portion that is adapted to connect to the tractor, and a rear portion with at least two tires. A second wireless hub is integrated with the trailer. At least one sensor is integrated with the tractor and at least one sensor is integrated with the trailer. A telematics module is integrated with the trailer. In operation, the first wireless hub communicates with the second wireless hub by way of WiFi with a first network protocol, thereby establishing a first level of a vehicle area network (VAN) comprising the first wireless hub and the second wireless hub. The first wireless hub also establishes a first subnetwork in and around the tractor with a network protocol different than the first network protocol, and communicates with the first sensor via the first subnetwork, the first subnetwork being within a second level of the VAN. The second wireless hub establishes a second subnetwork in and around the trailer with the network protocol different than the first network protocol, that is separate and distinct from the first subnetwork, and communicates with the second sensor via the second subnetwork, the second subnetwork being within the second level of the VAN. The second wireless hub communicates data to the telematics unit wirelessly. The at least one sensor that is integrated with the trailer preferably includes a tire-pressure-measurement sensor that is located inside one of the at least two tires and communicates data to the second wireless hub wirelessly. Preferably, the tractor-trailer vehicle also includes a transmitter/receiver that is integrated with the trailer, and acts as a range extender for the at least one sensor when the at least one sensor and the second wireless hub communicate with one another.

Still another embodiment of the subject disclosure is directed to a piston assembly attached to a bellows assembly in a suspension system. The piston assembly includes a housing with an upper end connected to the bellows assembly and a lower end connected to a leaf spring of the vehicle suspension system. The housing includes a channel and an internal cavity proximate the lower end and connected to the channel. A top plate is within an upper portion of the cavity. A first bolt extends through a mounting hole of the top plate and into the channel to secure the top plate to the housing. A sensing element within the cavity has an upper flange contacting the top plate so the upper flange flexes in response to a load. The sensing element includes strain gauges on a top surface for measuring flexure of the upper flange, a lower hexagonally-shaped end, and another channel aligned with the first bolt. Another bolt extends through the leaf spring and the another channel to secure the leaf spring to the sensing element.

The present disclosure also includes a load sensing system for a suspension system of a vehicle. The suspension system has a steering axle. The load sensing system includes a bracket adjacent the steering axle at a first location proximate a center of the steering axle, the bracket extending adjacent the steering axle, and a contactless sensor configured to measure a displacement distance between the bracket and a second location of the wheel axle, the second location being away from the center of the steering axle. The contactless sensor may include an eddy current sensor configured to detect the displacement distance based on movement of the steering axle. The suspension system may have a steering axle, the load sensing system comprising a contactless sensor positioned offset from a sloped end portion of the steering axle, the contactless sensor configured to measure a change in distance between the contactless sensor and the steering axle in both a loaded vehicle state and an unloaded vehicle state to determine a vehicle load. The contactless sensor can comprises an eddy current sensor configured to detect the displacement distance based on movement of the steering axle.

Still another embodiment is directed to a load sensing system for a suspension system of a vehicle wherein the suspension system having a leaf spring coupling a wheel axle to a chassis. The load sensing system includes a bracket adjacent to the leaf spring at a first location of the leaf spring proximate the wheel axle, the bracket extending substantially parallel to the leaf spring when in an unloaded state, the bracket extending to a second location of the leaf spring away from the wheel axle, and a contactless sensor configured to measure a displacement distance between the bracket and a second location of the leaf spring, the second location being away the wheel axle.

In another version, the load sensing system includes a bracket attached to a first location of the leaf spring and extending adjacent to the leaf spring, and a contactless sensor configured to measure a displacement distance between the bracket and a second location of the leaf spring. Still yet another embodiment of the subject disclosure is directed a load sensing system comprising a magnetic rotation sensor attached to the chassis and configured to measure a deflection distance of the leaf spring relative to the wheel axle to determine a vehicle load.

In one embodiment, a suspension system for a vehicle includes a chassis configured to support a body of the vehicle, a steering axle having a first end connected to the chassis at a first location on the chassis and having a second end connected to the chassis at a second location on the chassis, a first leaf spring coupled to the steering axle proximate to the first end of the steering axle and between a first end and second end of the first leaf spring, a first pivot fixedly connected to the chassis at a third location on the chassis and rotatably coupled to the first end of the first leaf spring, a first shackle and a second shackle forming a first pair of opposing shackles connecting the second end of the first leaf spring to the chassis, each of the first shackle and the second shackle being rotatably connected to a first bolt, the first bolt being rotatably connected to the second end of the first leaf spring, each of the first shackle and the second shackle being also connected to a second bolt, the second bolt being connected to the chassis, a second leaf spring coupled to the steering axle proximate the second end of the steering axle and between a first end and second end of the second leaf spring, a second pivot fixedly connected to the chassis at a fourth location on the chassis and rotatably coupled to the first end of the second leaf spring, a third shackle and a fourth shackle forming a second pair of opposing shackles connecting the second end of the second leaf spring to the chassis, each of the third shackle and the fourth shackle being rotatably connected to a third bolt, the third bolt being rotatably connected to the second end of the second leaf spring, and each of the third shackle and the fourth shackle rotatably connected to a fourth bolt, the fourth bolt being connected to the chassis, wherein each shackle of the first shackle, the second shackle, the third shackle, and the fourth shackle comprises a cavity at substantially a center location of the shackle, the cavity having a depth substantially halfway through a width of the shackle, a strain gauge at substantially a center location of each of the cavities, a rear axle of the vehicle, at least one bellows positioned between a rear leaf spring connected to the rear axle and the chassis to provide a rear suspension system for the vehicle, and a piston attached to the bellows. The piston includes a housing having an upper end configured to connect to the bellows and a lower end configured to connect to the rear leaf spring, the housing comprising a first central channel and an internal cavity proximate the lower end and connected to the first central channel. A top plate is within an upper portion of the cavity, and a fifth bolt extends through a second central channel of the top plate and into the first central channel to secure the top plate to the housing. A sensing element is positioned within the cavity, the sensing element having an external flange in contact with the top plate such that the external flange flexes in response to a vehicle load, the sensing element comprising a plurality of strain gauges on a top surface of the sensing element to measure flexure of the external flange, the sensing element comprising a lower hexagonally-shaped end and a third central channel aligned with the fifth bolt. A sixth bolt extends through the rear leaf spring and the third central channel to secure the rear leaf spring to the sensing element. One or more processing devices are in communication with the plurality strain gauges and configured to process measurements from the strain gauges and a display device is in communication with the one or more processing devices and configured to display processed measurements from the strain gauges, wherein a first moment distance between the first bolt and the first pivot is substantially twice a second moment distance between the first location and the third location on the chassis, and wherein a third moment distance between the third bolt and the second pivot is substantially twice a fourth moment distance between the second location and the fourth location on the chassis. And another embodiment is directed to a sensing device for sensing strain including strain gauges arranged in a bridge network configuration. The bridge network configuration is a first ring of strain gauges arranged in a Wheatstone bridge configuration, the Wheatstone bridge configuration comprising first and second bridges of sensors electrically connected in parallel to a common source and a common reference, and a second ring of strain gauges comprising third and fourth bridges of sensors, the third bridge of sensors being connected to the common source and to the common reference and in parallel with the first bridge, and the fourth bridge of sensors being connected to the common source and to the common reference and in parallel with the second bridge. The bridge network configuration may further include a third ring of strain gauges comprising fifth and sixth bridges of sensors, the fifth bridge of sensors being connected to the common source and to the common reference and in parallel with the first bridge and the third bridge, and the sixth bridge of sensors being connected to the common source and to the common reference and in parallel with the second bridge and the fourth bridge. Preferably, at least some of the strain gauges have resistances that vary in response to applied strain.

Another suspension system for a vehicle includes a chassis to support a body of the vehicle, a wheel axle having a first end connected to the chassis at a first location on the chassis and a second end connected to the chassis at a second location on the chassis, a first leaf spring coupled to the wheel axle proximate the first end of the wheel axle and between a first end and second end of the first leaf spring, a first pivot fixedly connected to the chassis at a third location on the chassis and rotatably coupled to the first end of the first leaf spring, a first shackle and a second shackle forming a first pair of opposing shackles connecting the second end of the first leaf spring to the chassis, each of the first shackle and the second shackle being rotatably connected to a first bolt, the first bolt being rotatably connected to the second end of the first leaf spring, and each of the first shackle and the second shackle being connected to a second bolt, the second bolt being connected to the chassis, a second leaf spring coupled to the wheel axle proximate the second end of the wheel axle and between a first end and second end of the second leaf spring, a second pivot fixedly connected to the chassis at a fourth location on the chassis and rotatably coupled to the first end of the second leaf spring, and a third shackle and a fourth shackle forming a second pair of opposing shackles connecting the second end of the second leaf spring to the chassis, each of the third shackle and the fourth shackle being rotatably connected to a third bolt, the third bolt being rotatably connected to the second end of the second leaf spring; and each of the third shackle and the fourth shackle being connected to a fourth bolt, the fourth bolt being connected to the chassis, wherein each shackle of the first shackle, the second shackle, the third shackle, and the fourth shackle comprises a cavity at substantially a center location of the shackle, the cavity having a depth substantially halfway through a width of the shackle, as well as a strain gauge at substantially a center location of each of the cavities, wherein a first moment distance between the first bolt and the first pivot is substantially twice a second moment distance between the first location and the third location on the chassis, and a third moment distance between the third bolt and the second pivot is substantially twice a fourth moment distance between the second location and the fourth location on the chassis.

The present disclosure also provides a method for calibrating shackles configured to connect a chassis of a vehicle to a leaf spring of a suspension system. The method includes the steps of positioning a first shackle pair and a second shackle pair within a testing environment for testing, applying a test force to the first shackle pair and to the second shackle pair such that a strain gauge in the first shackle pair generates a first sensor reading and a strain gauge in the second shackle pair generates a second sensor reading, and calibrating the shackles for an expected vehicle load based on the test force, the first and second sensor readings, and a ratio of a first moment distance to a second moment distance, wherein the first moment distance is based on a distance between a shackle and a connection point of the leaf spring and the second moment distance is based on a distance between the connection point and a center point of the leaf spring.

In one aspect, the shackle is for a suspension system of a vehicle. The vehicle has a wheel axle connected to a chassis via a leaf spring. The shackle has a first end configured to couple to the chassis via a first connector, a second end configured to couple to the leaf spring via a second connector, and a cavity at substantially a center location of the shackle, the cavity having a depth substantially halfway through a width of the shackle. A strain gauge is at substantially a center location of the cavity and configured to measure strain through the shackle. Preferably, the cavity is bow-shaped such that the cavity has a center that is narrower than wider opposing ends, wherein the shackle comprises a pair of parallel channels one a side of the shackle opposite the cavity, the pair of parallel channels extending between the wider opposing ends.

In still another embodiment, the subject technology provides a suspension system for a vehicle, comprising a flexible bellows pressurized with air, a piston configured to contact the flexible bellows, the piston comprising a piston housing having a cavity therethrough, a sensing device in the cavity configured to measure strain, a flexible member connected to the piston and configured to move in response to force applied from the vehicle, wherein movement of the flexible member causes the piston to move against the bellows and thereby register strain in the strain gauges, and a central processing system on the vehicle that is programmed to obtain strain measurements from the sensing device over a computer network. The strain gauges may be arranged on the sensing device in a bridge network configuration. The suspension system may include a leaf spring connected to a chassis of the vehicle using shackles, each shackle comprising a strain gauge for measuring strain during operation of the vehicle, the central processing system being programmed to obtain strain measurements from one or more strain gauges over a computer network.

Any two or more of the features described in this specification, including in this summary section, may be combined to form implementations not specifically described in this

specification.

At least part of the systems and methods described in this specification may be configured or controlled by executing, on one or more processing devices, instructions that are stored on one or more non-transitory machine-readable storage media. Examples of non- transitory machine-readable storage media include read-only memory, an optical disk drive, memory disk drive, and random access memory. At least part of the systems and methods described in this specification may be configured or controlled using a computing system comprised of one or more processing devices and memory storing instructions that are executable by the one or more processing devices to perform various control operations.

The details of one or more implementations are set forth in the accompanying drawings and the following description. Other features and advantages will be apparent from the description and drawings, and from the claims. DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the disclosed system appertains will more readily understand how to make and use the same, reference may be had to the drawings. Figure 1 is an exemplary tractor-trailer vehicle utilizing a vehicle area network in accordance with the subject technology.

Figure 2A is an exploded view of a wireless hub in accordance with the subject technology.

Figure 2B is a block diagram schematic view of a wireless hub in accordance with the subject technology.

Figure 3 A is an exploded view of a range extender in accordance with the subject technology.

Figure 3B is a block diagram schematic view of a range extender in accordance with the subject technology.

Figure 4A is a perspective view of a beacon in accordance with the subject technology.

Figure 4B an exploded view of a beacon in accordance with the subject technology.

Figure 5 is another exemplary tractor-trailer vehicle utilizing a vehicle area network in accordance with the subject technology.

Figure 6A is a portion of a flowchart for automatically ordering the trailers of the vehicle of Figure 5 in accordance with the subject technology.

Figure 6B is a portion of a flowchart for automatically ordering the trailers of the vehicle of Figure 5 in accordance with the subject technology.

Figure 6C is a portion of a flowchart for automatically ordering the trailers of the vehicle of Figure 5 in accordance with the subject technology.

Figure 6D is a portion of a flowchart for automatically ordering the trailers of the vehicle of Figure 5 in accordance with the subject technology.

Fig. 7 is a mechanical diagram showing a perspective view of an example vehicle. Fig. 8 is a mechanical diagram showing a perspective view of example components of an air suspension system that may be incorporated into a trailer in accordance with the subject technology.

Fig. 9 is mechanical diagram showing a partial cut-away side view of some of the components of the air suspension of Fig. 8.

Fig. 10 is a mechanical diagram showing a top perspective view of example components of an air suspension system that may be incorporated into a truck.

Fig. 11 is a mechanical diagram showing an underside perspective (upside down) view of example components shown in Fig. 10.

Fig. 12 is mechanical diagram showing a partial cut-away perspective view of some of the components of the air suspension of Fig. 10.

Fig. 13 is a mechanical diagram showing a cut-away side view of an example piston and an example leaf spring that may be included in an air suspension system for a vehicle.

Fig. 14 is a mechanical diagram showing a close-up cut-away side view of the piston and part of the leaf spring shown in Fig. 13.

Fig. 15 is a mechanical diagram showing an underside perspective (upside down) view of an example piston housing attached to a leaf spring.

Fig. 16 is a mechanical diagram showing an underside perspective (upside down) view of the piston housing without the leaf spring attached.

Fig. 17 is a mechanical diagram showing a cut-away perspective view of part of an example piston.

Fig. 18 is a mechanical diagram showing a cut-away side view of the part of the piston of

Fig. 17. Fig. 19 is a mechanical diagram showing a top perspective view that includes examples of a sensing element, a top plate, and a bolt configured to fit within a piston housing.

Fig. 20 is a mechanical diagram showing an underside perspective (upside-down) view that includes the sensing element, the top plate, and the bolt of Fig. 19.

Fig. 21 is a mechanical diagram showing a cut-away side view of the sensing element, the top plate, and a wireless transmitter module of Fig. 19.

Fig. 22 is a mechanical diagram showing a close-up zoomed-in view of part of the underside perspective (upside down) view of the piston housing shown in Fig. 16.

Fig. 23 is a mechanical diagram showing a top perspective view of an example sensing element of the type shown in Figs. 19 to 22.

Fig. 24 is a mechanical diagram showing a top perspective view of the example sensing element of Fig. 23 containing a printed circuited board attached thereto.

Fig. 25 is a mechanical diagram showing a top view of the example sensing element of Fig. 22 along with strain gauges depicted conceptually relative to the sensing element.

Fig. 26 is a circuit diagram showing an example strain gauge configuration that may be mounted on or near the top surface of the sensing element of Fig. 25.

Fig. 27 is a circuit diagram showing a standard Wheatstone bridge configuration circuit.

Fig. 28 is a circuit diagram showing another example strain gauge configuration that may be mounted on or near the top surface of the sensing element of Fig. 25.

Fig. 29 is a mechanical diagram showing a perspective view of parts of an example vehicle suspension system that include a chassis, a steering axle, a shackle, and a leaf spring.

Fig. 30 is a mechanical diagram showing a side view of one side of the example vehicle suspension system shown in Fig. 29. Fig. 31 is a mechanical diagram showing front and back views of an example shackle connected to a leaf spring of the type shown in Figs. 29 and 30.

Fig. 32 is a mechanical diagram showing an example shackle pairing connected by bolts.

Fig. 33 is a mechanical diagram showing a front view of an example shackle.

Fig. 34 is a mechanical diagram showing a back view of the example shackle of Fig. 33.

Fig. 35 is a mechanical diagram showing a perspective view of the example shackle of Figs. 33 and 34.

Figs. 36 and 37 are a mechanical diagrams showing two different orientations of an example shackle cavity containing a strain gauge.

Fig. 38 is a mechanical diagram showing the example shackle pairing of Fig. 32 with a test force depicted conceptually applied thereto.

Fig. 39A is a mechanical diagram showing a side view of an example vehicle.

Fig. 39B is a mechanical diagram showing a top view of an example vehicle and components of an example suspension system included in the vehicle

Fig. 40 is a mechanical diagram showing a perspective view of examples of leaf springs, a bracket, an axle, and a contactless sensor on a leaf spring.

Fig. 41 is a mechanical diagram showing a side view of part of one of the leaf springs of Fig. 40, along with a bracket and a contactless sensor.

Fig. 42 is a mechanical diagram showing a perspective view of example leaf spring flexing relative to a bracket in response to applied force, along with a contactless sensor attached to the leaf spring.

Fig. 43 is a mechanical diagram showing a perspective view of an example steering axle.

Fig. 44 is a mechanical diagram showing a side view of the steering axle of Fig. 43. Fig. 45 is a mechanical diagram showing a perspective view of the steering axle of Fig. 43 containing examples of a bracket and a contactless sensor.

Fig. 46 is a mechanical diagram showing a close-up view of part of the perspective view of Fig. 45, which includes part of the bracket, the axle, and the contactless sensor.

Fig. 47 is a mechanical diagram showing a perspective view of examples of parts of a steering axle, a bracket, and a contactless sensor.

Fig. 48 is a mechanical diagram showing a close-up cut-away side view of parts of the example components shown in Fig. 47.

Fig. 49 is a mechanical diagram showing a perspective view of components of an example vehicle suspension system containing a contactless sensor.

Fig. 50 is a block diagram showing a top view of an example vehicle having an example vehicle area network (VAN), including a hub containing one or more central processors.

Like reference numerals in different figures indicate like elements. DETAILED DESCRIPTION

The subject technology overcomes many of the prior art problems associated with connecting tractors and trailers as well as gathering and managing data from resulting tractor- trailer vehicles. The advantages, and other features of the system disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain preferred embodiments taken in conjunction with the drawings which set forth representative embodiments of the present invention and wherein like reference numerals identify similar structural elements. As noted earlier, tractor-trailer vehicles are moving into the digital age, where customers and operators of such desire to employ numerous data collection devices, and to in turn, communicate that data from the tractor-trailer vehicles into the cloud. One major issue associated with this is the lack of an installed hardware base, yet a clear market demand for such capabilities exists. With that in mind, there is a clear need to provide easily retrofittable solutions to tractor-trailer vehicles that were originally not manufactured and fit with modern digital sensors, area networks, and telematics equipment. Further, there is also a commercial need to develop such systems that can be easily integrated into originally manufactured tractor- trailer vehicles with minimal engineering. Additionally, it is valuable to provide such systems that are easily integrate-able and connectable with various sensors, and other equipment used for data collection and manipulation, and transmission.

Referring now to Figure 1, an exemplary vehicle 100 is shown utilizing a vehicle area network (VAN) 101 in accordance with the subject technology. The vehicle 100 has a tractor 102 for pulling two trailers 104a, 104b. The tractor 102 may haul just a single trailer or multiple trailers, and as many as five. It is typically the responsibility of the truck driver to not only ensure the safe and proper operation of the vehicle 100 but to also connect and disconnect the trailers 104a, 104b. The tractor 102 also includes a cabin 103 having a dashboard (not explicitly shown) for presenting information related to the trailers 104a, 104b. The tractor 102 has front wheels 105a, which can be steered to control direction of the tractor 102. The tractor 102 also has rear wheels 105b. A dolly 106 facilitates mechanical connection of the first and second trailers 104a, 104b. The trailers 104a, 104b and dolly 106 also include wheels 107.

The trailers 104a, 104b and dolly 106 are equipped with a plurality of sensors for monitoring position, speed, temperature, pressure, weight and the like for various purposes. In Figure 1, the components of the VAN 101 such as sensors 110a-c are shown schematically to illustrate possible locations and configurations. The driver is provided with a pairing device 275 for making wireless connections between the VAN 101 and the sensors 110. The pairing device 275 also can monitor the status of the trailers 104a, 104b as well as connect to the devices of the VAN 101. The pairing device 275 may be a tablet, smart phone, or specialized controller and the like.

The VAN 101 establishes communication between numerous components of the vehicle 100. Individual components can be connected wirelessly, wired and combinations thereof. The connections may utilize various communication protocols, as will be discussed in more detail herein. The VAN 101 can utilize WiFi to establish a high bandwidth backbone, in effect a first level of the VAN 101. The VAN 101 may include any number of sub-networks, in effect second levels of the VAN 101. For example as shown in Figure 1, the VAN 101 includes a tractor subnetwork 112 and a trailer subnetwork 114. Each subnetwork 112, 114 includes one or more wireless hubs 130a-d. The first trailer 104a includes the wireless hub 130b, the dolly 106 includes the wireless hub 130c and the second trailer 104b includes wireless hub 130d. As the tractor 102, trailers 104a, 104 and dolly 106 are often reconfigured with other trailers and dollies, quick and easy pairing to establish the subsequent vehicle area network is beneficial.

The VAN 101 also includes a first telematics module 116a on the tractor 102 and in communication the tractor hub 130a as well as a second telematics module 116b on the first trailer 104 and in communication with the first trailer hub 130b. The telematics modules 116a, 116b also communicate with external networks 118 having external devices 120. The telematics modules 116a, 116b communicate with the external networks 118 via cell towers 122.

Preferably, the tractor 102 has a chassis CAN bus 124 over which the tractor hub 130a and the telematics module 116a communicate. The trailers 104a, 104b may be substantially identical or quite differently configured not just in terms of hardware but software. However, the VAN 101 can automatically integrate components so that the driver is needed for little pairing activity with the smart device 275 if any at all. Telematics modules and services are available commercially from numerous suppliers, such as Cal Amp of Irvine, California.

The wireless hubs 130a-d are powered by a wired power line communication (PLC) cable, typically connected by the driver when mechanically coupling the trailer 104a, 104b to the tractor 102. The wireless hubs 130a-d communicate using WiFi with a 802.15.4 thread network protocol and/or over the CAN bus 124. The wireless hubs 130a-d can also communicate by common lower power friendly means such as Bluetooth or 433 Mhz technology. The wireless hubs 130a-d can also use near-field communication as well as with any other wireless communication protocol now known or later developed.

The hubs 130a-d can be connected to one or more components or each other using a wired connection. For example, the tractor hub 130a can be connected to the front trailer hub 130b with a wired cable connection. The wired cable connection can optionally provide power from the tractor hub 130a to the trailer hub 130b while simultaneously allowing communication through PLC techniques. The wired connection can allow the tractor hub 130a and the first trailer hub 130b to automatically pair upon making the physical connection. During pairing, the hubs 130a, 130b communicatively connect utilizing the PLC connection to share credentials of the VAN 101 in accordance with out of band pairing techniques. Similarly, the hubs 130c, 13d can also be hard wired and automatically integrated into the VAN 101.

Each wireless hub 130a-d acts as central communication or access point for devices within the respective local area or subnetwork 112, 114 of the vehicle 100. To that end, the tractor wireless hub 130a creates the tractor subnetwork 112 for all devices in and around the tractor 102 of the vehicle 100. Similarly, the first trailer hub 130b creates the trailer subnetwork 114 for all devices in and around the first trailer 104a. Further, a wireless hub 130c on the dolly 106 is part of the first trailer subnetwork 114 but could even form another subnetwork. Other subnetworks may also be included, for example, for other additional trailers, dollies, and/or areas of the truck.

Still referring to Figure 1, the tractor wireless hub 130a establishes communication to the tractor telematics module 116a, the pairing device 275 and the first trailer wireless hub 130b to establish the tractor subnetwork 112. The tractor hub 130a can communicate with the first trailer hub 130b by PLC and/or WiFi, with the pairing device 275 by WiFi, and over the CAN bus 124 with the telematics module 116a. In one embodiment, the tractor hub 130a uses Thread networking communication technology based on the IEEE 802.15.4 radio standard for low power consumption and latency. The communication protocol may include AES 128 encryption with a media access control (MAC) layer network key.

The tractor 102 also includes a plurality of sensors 110a. For simplicity in Figure 1, only one sensor 110a is shown schematically, but represents any kind of sensor in any location. In order to facilitate communication between the tractor hub 130a and the sensor 110a, the tractor subnetwork 112 can include a transmitter/receiver 170a paired with the sensor 110a. Depending upon the sensor configuration, the sensor 110a may also communicate directly with the tractor hub 130a. The transmitter/receiver 170a and sensor 110a also utilize Thread networking communication technology among others.

For example, communication between the transmitter/receiver 170a and sensor 110a may be via Bluetooth communication. The transmitter/receiver 170a acts as a range extender for the sensor 110a. However, Bluetooth is susceptible to eavesdropping so that out of band (OOB) pairing is needed. The pairing device 275 is used to accomplish the OOB pairing. The pairing device 275 can use near-field communication (NFC) with the hubs 130a-d, sensors 110a-d and transmitter/receivers 170a-d.

Pairing the components 110a-d, 130a-d, 170a-d can use multiple technologies and techniques in any combination. The pairing device 275 can use WiFi or even read a barcode to link to the hub 130a. Once linked to the hub 130a, the pairing device 275 can use RFID technology such as an NFC tag to establish the OOD pairing connection to the

transmitter/receiver 170a and sensor 110a. NFC technology is desirable because the pairing device 275 could simply be a smart phone running an application and held in proximity to the transmitter/receiver 170a or sensor 110a. The OOD pairing link can use datagram transport layer security (DTLS), which is a communications protocol that provides security by allowing communication in a way that is designed to prevent eavesdropping, tampering, and message forgery. Additionally, access can be protected by using a pre-shared key (PSK) generated by an algorithm such a J-PAKE.

Once the pairing device 275 establishes communication between the hub 130a, sensor 110a and transmitter/receiver 170a, the tractor subnetwork 112 is established. In a similar manner, the trailer subnetwork 114 can be established. The first trailer hub 130b establishes the first trailer subnet 114 that also includes a plurality of sensors 110b. Again for simplicity, only a single sensor 110b is shown schematically representing, for example, a TPMS. A

transmitter/receiver 170b is paired with the sensor 110b. The first trailer 104a also includes a telematics module 116b and beacon 200, both of which are part of the first trailer subnetwork 114. The telematics module 116b communicates with external networks 118 via a cell tower 122 as well. The beacon 200 may also communicate directly, whether wired or wirelessly, with the tractor hub 130a.

The tractor hub 130a is also paired to the trailer hub 130b so that the respective subnetworks 112, 114 are in secure communication. To pair the hubs 130a, 130b, the OOB pairing link can use a physical connection with ISO 11992, which is a CAN based vehicle bus standard in the heavy-duty truck industry for communication between the tractor and one or more trailers. The pairing of the hubs 130a, 130b can share a unique data key such as a key generated by AES- 128 encryption.

The beacon 200 provides a separate means of transmitting information wirelessly. In particular, the beacon 200 can be configured to act as a GPS, transmitting location data for the first trailer, allowing a remote user to locate the trailer. The beacon 200 is particularly useful for tractor drivers who are picking up a trailer from a large lot of many trailers. For example, certain lots tend to store an enormous number of trailers and are not well organized or marked, requiring drivers to search to locate a particular trailer. Typically, the driver is tasked with seeking out the trailer through a particular identifier on the trailer, such as a license plate. This inefficiently requires the driver to look individually at the license plate of each trailer on the lot to determine whether it is the correct trailer. Further, license plates can be difficult to read accurately from a distance, requiring the driver to approach each license plate within a reasonable distance or even get out of the tractor. As such, the beacon 200 improves the manual searching process by providing a GPS signal to the external networks 118 which ultimately is received by telematics module 116a in the tractor 102. Thus, the beacon GPS signal can be used by the driver to quickly and easily locate the trailer 104a within the lot. It is envisioned that the dashboard of the tractor 102 may display not only the location of the beacon 200 but assist with directions on how to drive to the beacon 200. The beacon 200 can also include a clear visual identifier, such as a blinking light of a specified color or a display showing an identifier, to alert the driver when the driver is close to the correct trailer 104a. The beacon 200 eliminates the need for the driver to carefully search the entire lot and allows the driver to quickly and easily identify and connect to the proper trailer.

Still referring to Figure 1, the dolly 106 and second trailer 104b also include respective hubs 130c, 130d that become part of the VAN 101. The hubs 130c, 130d similarly communicate with a plurality of sensors 110c, 110d and any transmitter/receiver 170c, 170d paired with the sensors 110c, 110d. Depending upon the configuration, the hubs 130c, 130d may form subnetworks or simply communicate with the first trailer hub 130b, which relays the information to the tractor hub 130a. The second trailer 104b can include a telematics module, beacon and other hardware as needed.

Generally, a transmitter/receiver 170a-d is positioned proximate a respective sensor, which may be pressure, temperature, speed, position, or other sensors. The transmitter/receiver 170a-d receives measured data from one or more sensors and reports that data to the local hub wirelessly. The transmitter/receiverl70a-d may also use the 433 MHz frequency band for communication. In other cases, the sensors 110a-d are wired directly to the local hub 130a-d, or are connected wirelessly directly to the local hub 130a-d.

It is envisioned that the subnetworks 112, 114 can be established in advance. In other words, for the trailer subnetwork, pairing the sensor 110b, transmitter/receiver 170b and hub

130b can be accomplished during assembly by a technician using a pairing device 275. As noted above, the pairing may be very automatic, and to the extent needed, performed by the driver upon connection of the trailer 104a. Many sensors and such devices can be difficult to physically access so that pairing upon installation is advantageous. A sensor, for example, might be located on an axle of the vehicle or within a vehicle braking system. The driver or

technician's pairing device 275 may be able to read a code from the sensor, such as a QR code or NFC tag. The technician's pairing device 275 will be trusted by the VAN 101 (e.g. having passcode credentials for the network, or the like) and/or can be manually connected to the VAN 101, whether wired or wirelessly. The pairing device 275 can then pair the sensor 110b to the hub 130b using the code from the sensor 110b, thereby connecting the sensor 110b to the subnetwork 114 and, ultimately, to the VAN 101.

Once the transmitter/receivers 170a-d are paired for wireless communication to corresponding wireless hubs 130a-d, information can then be transmitted from multiple devices across the VAN 101. The data can be processed and provided to a central location of the vehicle 100, such as within the tractor 102 where the driver can see alerts, or other feedback related to the readings of the sensors 110a-d.

In some cases, one or more of the tractor 102 and trailers 104a, 104b can include a 3rd party, on-board telematics device 116a, 116b. In the example shown, the tractor hub 130a is in communication with a first telematics device 116a and the first trailer hub 130b is in

communication with a second telematics device 116b in the first trailer 104a. Each telematics device 116a, 116b transmits data to a third party source. In the example given, the data is transmitted to an external cloud platform where the data can then be obtained by external devices 120, such as computers, smartphones or the like (e.g., the pairing device 275). The data can then be relied upon for fleet and asset management functions, such as checking health of various components of the truck. In other cases, the telematics devices 116a, 116b can transmit to mediums other than a cloud network, such as a wide area network or directly to third party devices.

Once information from the VAN 101 is transmitted out of the vehicle 100 to the external networks 118 and devices 120, additional data review, analysis and insight can be ascertained. The analysis and insight can then be sent back to the trailer 102 for review by the driver. A suite of warning strategy functionality can be general or specific to particular needs. The algorithm that develops the warnings is optimized by ongoing data analysis. For example, the vehicle behavior is characterized so that particularly identified parameters can be measured. Some parameters are tire pressure with reference temperature, spare tire pressure, system temperature, system pressure, and gross vehicle weight (GVW). The external device 120 may have specific data such as a range or maximum allowable limit. Since the maintenance of these parameters is ongoing, if the GVW is over limit or out of range, or a tire is under low pressure or unsafe to drive on, a warning message can be sent to the driver for investigation and corrective action. For another example, a fast pressure loss in a tire would generate an alert to the driver.

The subnetworks 112, 114 for the vehicle 100 are part of and in local communication within the broader VAN 101, with one wireless gateway hub acting as an access point for the VAN 101. In some cases, the access point for the VAN 101 can change to a different gateway depending on the number of trailers 104 attached to the tractor 102 such that the access point is in a central location of the vehicle 100. To centralize the access point, the tractor hub 130a searches down the length of the vehicle 100 for additional hubs 130 to determine a centrally located hub 130. Since the hubs 130 will be somewhere along the length of the vehicle 100, the VAN 101 can determine hub locations through a linear search, rather than by searching a broad surrounding radius. If, for example, only a single trailer 104a is provided, the access point can be the wireless hub 130 in the center of the one trailer, which all devices (e.g., transmitter/receivers, sensors and the like) in the trailer 104a or tractor 102 can wirelessly reach. If the second trailer 104b is included, the access point could still be located within the first trailer 104a at a location central to the vehicle 100 or, alternatively at the dolly hub 130c which is also centrally located. If additional trailers are added (e.g. a third and fourth trailer), the access point can be changed to a new hub at a central location of the vehicle 100, or can use multiple interconnect access points to leap frog wireless signals through the entire length of the vehicle 100. Alternatively, a full WiFi mesh system could be used to connect many hubs at locations across the vehicle 100. Having wireless hubs 130a-d which control the central communication at each area of vehicle 100 allows many devices to quickly and easily communicate over the VAN 101, even when devices within the VAN 101 may be changed (e.g., sensor repair), or new or additional trailers and dollies may be added to the vehicle 100. In each case, each new device need only be paired and connected to one wireless hub, and data from all devices can be shared across the VAN 101. From the above, it should be understood that the exact number and arrangement of the components shown in Figure 1 are exemplary only, and should not be construed as limiting.

AUTONOMOUS VEHICLES

As vehicles become self-driving, the subject technology wills seamlessly integrate with the suite of autonomous technology. For example, the data analysis from monitoring the sensors can be used to control speed or even redirect the autonomous vehicle to a service station or rest stop to attend to repairs. The data analysis may also require the autonomous vehicle to enter an emergency mode where the vehicle may be pulled over for towing or control ceded to a remote operator. In one embodiment, the tractor and the trailer are merged as one. As would be expected, the integration of sensors on the trailer portion into the vehicle area network on the merged tractor-trailer is only required initially. The merged tractor-trailer can still connect and carry additional trailers.

WIRELESS HUBS

As used herein, a micro controller, computer or smart device is one or more digital data processing devices. Such a device generally can be a personal computer, computer workstation (e.g., Sun, HP), laptop computer, a tablet computer, server computer, mainframe computer, handheld device (e.g., personal digital assistant, Pocket PC, cellular telephone, etc.), information appliance, printed circuit board with components or any other type of generic or special-purpose, processor-controlled device, with or without application specific integrated circuits (ASICs), capable of receiving, processing, displaying, and/or transmitting digital data. A controller includes random access memory (RAM), mechanisms and structures for performing input/output operations, a storage medium such as a magnetic hard disk drive(s), and an operating system (e.g., software) for execution on a central processing unit (CPU). The controller also has input and output devices such as a display screen, a keyboard and mouse and the like.

A CPU generally is logic circuitry that responds to and processes instructions that drive a controller and can include, without limitation, a central processing unit, an arithmetic logic unit, an application specific integrated circuit, a task engine, and/or any combinations, arrangements, or multiples thereof. Software or code generally refers to computer instructions which, when executed on one or more digital data processing devices, cause interactions with operating parameters, sequence data/parameters, database entries, network connection parameters/data, variables, constants, software libraries, and/or any other elements needed for the proper execution of the instructions, within an execution environment in memory of the digital data processing device(s).

A module is a functional aspect, which may include software and/or hardware. Typically, a module encompasses the necessary components to accomplish a task. It is envisioned that the same hardware could implement a plurality of modules and portions of such hardware being available as needed to accomplish the task. Those of ordinary skill will recognize that the software and various processes discussed herein are merely exemplary of the functionality performed by the disclosed technology and thus such processes and/or their equivalents may be implemented in commercial embodiments in various combinations without materially affecting the operation of the disclosed technology.

Referring now to Figure 2A, an exploded view of a wireless hub 130 is shown. Each hub 130a-d may be differently configured, but in Figure 2A an exemplary hub 130 is shown. The wireless hub 130 includes an enclosure 131 with a removable lid 132 that connects to form a protected interior 133. The enclosure 131 forms opposing recesses 134 for compression limiters 135 to maintain the joint integrity of the plastic enclosure 131. The hub 130 includes a printed circuit board (PCB) 136 having electronics, such as a processor and memory (not explicitly shown) required to create modules to carry out the functions of the wireless hub 130, including data processing, storage, and transmission.

The wireless hub 130 has an antenna 137 connected to the PCB 136 for wireless transmission. Additional antennas may be included as needed to allow the hub 130 to transmit and receive data with other devices as described herein. For wired connections, the hub 130 includes connecting pins 138. The hub 130 may be powered by a battery and/or from a wired connection. In one embodiment, the hub 130 is connected to a +12/24V supply 144 (see Figure 2B). The wireless hub 130 is configured to withstand large temperature changes in the range of - 40 °C to +85 °C. The hub 130 mounts external to the tractor cabin such as on the chassis rail.

Referring now to Figure 2B, a schematic diagram of a micro controller 140 suitable for use as a portion of the wireless hub 130 is shown. Typically, the micro controller 140 is part of the PCB 136 of Figure 2 A. The PCB 136 includes additional separate peripheral modules 141, 142, 143, 144, 145 and such may be incorporated into the micro controller 140. The micro controller 140 and modules 141, 142, 143, 144, 145 may include one or more standardly available components or be fabricated as one or more ASICs.

The hubs 130a-d can transmit and/or receive data between other hubs and/or range extenders 170a-d using a WiFi module 141 with a 2.4GHz frequency band. The WiFi module 141 creates tractor-to-trailer transparent IP -based data communication. A second 802.15.4 thread network protocol communication module 142 can send and receive additional sensor content and range extension. A third communication module 143 can use sub-GHz (e.g., a 433 MHz frequency band) with on-board decode and polling functionality for low power modes. The third communication module 143 is particularly well-suited for data from nearby sensors that are battery powered and, thus, low power.

The micro controller 140 can also be connected for communication to a CAN bus 145, which is typically located in the tractor 102. The micro controller 140 can also be directly connected to another wireless hub 130 so that the hub 130 can act as a radio frequency (RF) to CAN gateway. The PCB 136 also includes a 12/24 V power supply 144 with surge protection to power and protect the micro controller 140 and other components from electrical damage.

When the micro controller 140 is operating, hardware 147 creates a runtime environment (RTE) 146 so that the stored programs are running (e.g., instructions are being executed). The hardware 147 includes a processor 148 coupled to memory 149 along with other components not explicitly shown. Programs are stored in the memory 148 and accessed by the processor 149. A boot loader module 150 allows programming to the memory 148. An operating system module 151 allows the user to interface with the hardware 147. An ECU abstraction layer module 152 facilitates uniform access to the micro controller functions performed by peripherals and application program interfaces (APIs). A MCAL micro controller abstraction layer module 153 facilitates direct access to the devices on the PCB 136. A complex device drive module 154 includes various sub-modules 155a-c to implement drivers for the communication devices 141, 142, 143 as needed. The boot-loader module 150 can run the micro controller 140 for programming and writing information to the memory 149.

As can be seen, the micro controller 140 is specifically designed for use in the VAN 101. The micro controller 140 also includes a power manager module 156 and a tag-to-tag network link module 157. The micro controller 140 includes a TPMS module 158 and onboard weight motor vehicle unit module 159 to accomplish TPMS and MVU weight measurements in the VAN 101. The micro controller 140 also includes a RF network management module 160 and a third party software component module 161 to facilitate use of RF network components and third party software. Other modules may be present in the micro controller 140 to accomplish any desired features in the VAN 101. Further, the micro controller 140 features may be expanded by having hardware and software ready to host additional software and support other components (e.g., additional sensors, hubs, subnetworks).

TRANSMITTERS/RECEIVERS

Referring now to Figures 3 A and 3B, an exploded view and a schematic view of an exemplary transceiver/receiver 170 are shown, respectively. The transmitter/receiver 170 includes an enclosure 171 forming a cavity 172 that is sealed with a lid 173 for protection of a printed circuit board (PCB) 174. Again, one or more compression limiters 175 fit in the enclosure 171 to maintain the joint integrity of the plastic enclosure 171. The PCB 174 includes the electronics to carry out all the functions of the transmitter/receiver 170 including

sending/receiving data, data processing, and storage. The PCB 174 may include a processor, memory, an antenna and other components (not explicitly shown).

For wired connections, the transmitter/receiver 170 includes a connector 176. The transmitter/receiver 170 may be powered by a battery and/or from a wired connection. In one embodiment, the hub 130 is connected to a +12/24V supply 183. The transmitter/receiver 170 is also configured to withstand large temperature changes in the range of -40 °C to +85 °C.

Preferably, the transmitter/receiver 170 can mount in any suitable location but outside the chassis rail is preferred.

Typically, most, if not all functional modules, are created by components of the PCB 174 but one or more peripheral components 181, 182, 184 could also be utilized. The PCB 174 may include one or more standardly available components or be fabricated as one or more application specific integrated circuits (ASICs). The components of the PCB 174 work together to form a central processing unit 180.

The transmitter/receiver 170 can transmit and/or receive data to hubs and/or other transmitter/receiver 170 using a 802.15.4 thread network protocol communication module 181 as well as send and receive additional sensor content. Thus, the transmitter/receiver 170 can be used to enlarge the size of the VAN 101. A sensor communication module 182 uses sub-GHz (e.g., a 433 MHz frequency band) for low power modes to efficiently work with nearby sensors that are battery powered. When the transmitter/receiver 170 is operating, a runtime environment (RTE) 183 is created so that the stored programs are running (e.g., instructions are being executed). The PCB 174 may include a processor coupled to memory along with other components not explicitly shown. The programs are stored in the memory and accessed by the processor. One program is an operating system module 184 that allows the user to interface with the hardware 147, typically using the pairing device 275.

A hardware abstraction layer module 185 facilitates uniform access to the range extender functions. A supplier software development kit (SDK) module 186 facilitates creation of applications with advanced features specific to the transmitter/receiver 170 and operating system module 184. The PCB 174 includes a communications stack module 187 to support the 802.15.4 thread network protocol communication module 182.

As can be seen, the transmitter/receiver 170 is specifically designed for use in the VAN 101. The transmitter/receiver 170 includes a power manager module 188 and a packet forwarder module 189 for assisting with data conversion. The transmitter/receiver 170 also includes a diagnostic and commissioning module 190 that provides a user interface via the smart device 275 for start-up and troubleshooting purposes. Other modules may be present in the

transmitter/receiver 170 to accomplish any desired features in the VAN 101. Further, the transmitter/receiver 170 features may be expanded by having hardware and software ready to host additional software and support other components.

The transmitter/receiver 170 is particularly beneficial when retrofitting technology on to an existing trailer or tractor for future incorporation into a vehicle area network. The

transmitter/receiver 170 may connect to various sensors, wired or wirelessly, then pass along the data to a wireless hub. In effect, the transmitter/receiver 170 is the additional hardware to bridge communications with existing hardware to the new networked components.

TIRE PRESSURE MONITOR SYSTEM

Further, the sensors may also be retrofit. For example, see U.S. Patent Application No. 16/119,109 filed on August 31, 2018 entitled TIRE PRESSURE MONITOR WITH VARIABLE

ANGLE MOUNTING, which is incorporated herein by reference. In addition to sensors indicating the tire pressure, the sensors may auto-locate or be programmed to indicate wheel position. As such, when the VAN 101 identifies a pressure reading, the pressure reading is associated with a specific tire. The tire-related data can include temperature data as well, which is also an indication of proper and improper performance.

It is envisioned that the smart device 275 can be used to assist in refilling tire pressure alleviating the need for a tire pressure gauge by having the pressure reading on the smart device 275 or other indicia, such as beeping the horn/flashing the lights, to indicate that the pressure is within specification. If the tire is equipped with automatic tire fill, the VAN 101 can trigger refill and stop at the desired pressure. The sensors can also provide an indication that the lift axle is lowered but the tire is not turning. In this instance, a tire lock warning could be generated and/or acted upon such as in an autonomous vehicle. Similarly, a tire blow out can be detected quickly after the burst event to send a warning indicating the blow out and location. In the self- driving vehicle, the tire burst warning generates a reaction for safety and control. Preferably, the sensors are battery powered with efficient power usage for long life.

BEACONS

Referring now to Figures 4A and 4B, a perspective and a bottom exploded view of a beacon 200 in accordance with the subject technology is shown. The beacon 200 may mount to the trailer 104a magnetically, with a bracket or by any other fastener. A bottom plate 202 forms two recesses 204. Screws 206 hold magnets 208 in the recesses 204 so that the beacon 200 can simply be placed against the trailer 104a for mounting and easily removed without tools for wireless charging, relocation, repair and the like. The bottom plate 202 has an indicia arrow 210.

The beacon 200 also includes a rechargeable battery 212 for a power source. A printed circuit board (PCB) 214 has an LED 216 (shown in dashed lines) that illuminates to show such information as the status of the trailer 104a (e.g., connected to the VAN 101 (e.g., solid light) or in process of being connected (e.g., flashing light)). The PCB 214 also has components to wirelessly communicate with the hubs 130a-d and or transmitter/receivers 170a-d. The PCB 214 is also equipped to interface with a smart device 218 that can use near-field communication (NCF). The PCB 214 also has a GPS module 220 (shown in dashed lines) so that the VAN 101 can locate the beacon 200, and in turn the trailer 104a at a great distance as described above.

The beacon 200 also has a PCB top plate 222 for protecting the PCB 214. The PCB top plate 222 has a translucent window 224 aligned with the LED 216. A top cover 226 couples to the bottom plate 202 to seal the battery 212, PCB 214 and PCB top plate 222 within an oval housing 228. Preferably, the top cover 226, bottom plate 202, PCB 214, PCB top plate 222 and oval housing 228 have features 230 for screwing together. The PCB top plate 222 and top cover 226 also have a plurality of aligned holes 232.

MULTI-TRAILER ORDERING

Referring now to Figure 5, another exemplary vehicle area network (VAN) 301 for a tractor-trailer vehicle 300 is shown. The components and functionality of the VAN 301 and tractor-trailer vehicle 300 can be similar to the vehicle 100 and VAN 101 described above, except as otherwise indicated herein. Thus, like reference numerals in the“3” series represent similar components. For clarity, several components are not shown.

The vehicle 300 includes a tractor 302 with three trailers 304a-c and two dollies 306, all including components similar to those discussed with respect to Figure 1. The VAN 301 allows for communication between all of the components of the vehicle 300, such as wireless hubs

330a-d, sensors 310a-f (e.g., TPMS, pressure sensors, temperature sensors and the like), beacons 200, and the like, as discussed above. The tractor 302 and each trailer 304a-c have a

corresponding subnetwork 314a-c within the VAN 301 which connects the components proximate the respective trailer 304a-c. Although not shown, it is envisioned that the VAN 301 includes transmitter/receivers and other components as desirable for robust performance. Each trailer 304a-c also includes a beacon 200 for assisting the driver in assembling the vehicle 300.

It is advantageous for the VAN 301 to be informed of the relative location of the trailers 304a-c and/or subnets 314a-c established on the vehicle 300. The VAN 301 having the relative location helps to identify where various sensors, and other components such as the tires, are located. In some cases, it can be a challenge for the VAN 301 to identify the exact ordering of the trailers 304a-c. Further, even if this is manually calibrated, trailers are often dropped off, and new trailers picked up and attached to the truck, requiring the new trailers to be ordered within the VAN 301. Therefore, it is advantageous for the VAN 301 to be capable of connecting to and establishing communication with trailers automatically and determining an order of the trailers.

Referring now to Figures 6A-6D, a flowchart 600 of a method for automatically recognizing the order of three trailers 304a-c on the vehicle 300 is shown. The method relies on data, including signal strength and time of flight (ToF) to continuously monitor and update the status of the vehicle 300. The flowchart herein illustrates the structure or the logic of the present technology, possibly as embodied in computer program software for execution on by the hardware described herein. Those skilled in the art will appreciate that the flowchart illustrates the structures of the computer program code elements, including logic circuits on printed circuit boards having integrated circuits that function according to the present technology. As such, the present technology may be practiced by a machine component that renders the program code elements in a form that instructs a digital processing apparatus (e.g., micro controller or computer) to perform a sequence of function step(s) corresponding to those shown in the flowchart.

At step 602, the method starts with the micro controller of each hub 330a-d being powered up and in normal operation to form the respective subnetworks 312, 314a-c but, at this time, the trailer order is unknown and the trailers 304a-c can be in any order. At step 604, each subnetwork 312, 314a-c monitors received signal strength indicators (RSSI) and ToF data from all other subnetworks 312, 314a-c. If other hubs were not present, the same data could come from range extenders or even directly from sensors.

At steps 606 and 608, the tractor hub 330a identifies a trailer subnetwork 314a with the highest RSSI and the shortest ToF. The trailer subnetwork 314a with the highest RSSI and shortest ToF should be the lead trailer 304a physically closest to the tractor 302. At step 610, the tractor hub 330a compares the subnetwork 314a identified with the highest RSSI to the subnetwork 314a with the shortest ToF. If the subnetworks of steps 606 and 608 do not match, meaning the subnetwork with the highest RSSI is different from the subnetwork with the shortest ToF, the method restarts at step 602. At step 612, if there is a match by both being subnetwork 314a, subnetwork 314a is identified as being on the first trailer 314a (e.g., the lead trailer). Further, if at step 610, there is only an RSSI and ToF from the same subnetwork 314a, then the tractor subnetwork 312 can identify the associated trailer 304a as the one and only trailer present.

After the lead trailer 304a is identified successfully, the lead trailer wireless hub 330b identifies the subnetwork 314b with the highest RSSI and the shortest ToF with respect thereto, excluding the tractor subnetwork 312 in both cases at steps 614 and 616. At step 618, if there is a match, then the respective subnetwork 314b is identified as the second trailer 304b

immediately after the lead trailer 304a at step 620 as shown on Figure 6b. If there is no match at step 618, the method restarts at step 602. In another embodiment, the method restarts at step 612 by using the previously established lead trailer identification. If at steps 614 and 616, there are only an RSSI and ToF from two subnetworks 314a, 314b, then the tractor subnetwork 312 can identify and order the associated two trailers 304a, 304b. In one embodiment, the process end after successful identification at step 620.

Once the second trailer 304b is identified, any of the hubs 330a, 330b or the trailer wireless hub 330c of the second trailer 304b can identify the third trailer 304c. To that end, in the following description the second trailer wireless hub 330c is used. At steps 622 and 624, the hub 330c identifies the subnetwork 314c with the highest RSSI and the shortest ToF excluding the tractor subnetwork 312 and the lead trailer subnetwork 314a in both cases. At step 626, if there is a match, it is assumed the identified subnetwork 314c corresponds to the third trailer 304c (i.e. the trailer 304c immediately after the second trailer 304b). The third trailer 304c is identified at step 628 based on the third trailer subnetwork 314c, as shown on Figure 6b. If there is no match at step 626, the entire process is restarted at step 602 but may alternatively return to step 620.

The steps to identify the next trailer in a line of trailers can be repeated for additional trailers, as would be understood by one of skill in the art. Assuming the vehicle 300 has three trailers 304a-c, as in the example of Figure 5, the first results ordering the three trailers 304a-c have then be determined at step 630, which indicate an initial order of all the trailers 304a-c. If at steps 622 and 624, there are only an RSSI and ToF from three subnetworks 314a-c, then the tractor subnetwork 312 can identify and order the associated three trailers 304a, 304b and end the method or proceed with a double check as follows. For more trailers, the method may continue.

After step 630 to double check, the process of determining the order of the trailers 304a-c is then substantially repeated, in reverse order, to get a second set of results for comparison to determine whether the initial ordering was accurate. In more detail, referring now to Figure 6c, the method continues to monitor RSSI and ToF data from all other subnetworks 314a-c at step 632. At steps 634 and 636, starting with the identified third trailer 304c, the third trailer subnetwork 314c identifies the subnetwork 314b with the highest RSSI and the shortest ToF by comparing data from all of the identified subnetworks 312, 314a-b. At step 638, subnetwork(s) with the highest RSSI and the shortest ToF are compared. If the identified subnetworks with the highest RSSI and the shortest ToF are different, the method restarts to step 632, but if there is a match, then the identified subnetwork 314b is determined to correspond to the second trailer 304b. The identification of location of the second trailer 304b is saved as part of the second set of results at step 640.

At steps 642 and 644, the newly identified second trailer subnetwork 314b then identifies the highest RSSI and the shortest ToF excluding the third trailer subnetwork in both cases. At step 646, the second trailer subnetwork 314b compares the identified subnetworks, typically subnetwork 314a for each criteria. If there is a match, then the identified subnetwork (e.g., subnetwork 314a) is determined to correspond to the lead trailer 304a and saved as part of the second set of results at step 648. If the identified subnetworks are different at step 646, the method restarts at step 632.

Referring now to Figure 6d, the identified lead trailer subnetwork 314a then identifies the subnetwork with the highest RSSI and with the shortest ToF excluding the second and third trailer subnetworks 314b-c, in both cases at steps 650 and 652. At step 654, the lead trailer subnetwork 314a compares the identified subnetworks. If there is a match, properly being the tractor subnetwork 312, then the method proceeds to step 640 where the identified tractor subnetwork 312 is determined to correspond to the tractor 302. The method gathers and saves the information related to the three properly located subnetworks 312, 314a-b as part of the second set of results at step 658.

At step 660, with the subnetworks 312, 314a-b identified and ordered a second time, the first and second set of results are then compared. If the ordering determined in the first set of results is consistent with the ordering determined in the second set of results, then it is verified that order of the VAN subnetworks 312, 314a-c have been correctly determined and the method ends at step 662. Otherwise, if the order determined in the first and second set of results is different, then the method starts over at step 602 so a verified order can be determined.

In this way, the VAN 301 is able to automatically determine an order of the trailers 304a- c based on the order of the subnetworks 330b-d with no input from the user. The order of the trailers 304a-c can then be relied upon to determine where various sensors are located, and to easily take action based on a sensor readings and/or alert. For example, if a tire pressure monitoring sensor reports data that triggers a low pressure alert, it is advantageous for the user to be able to narrow down the potential tire(s) corresponding to that alert. A given sensor's subnet can be used to determine which trailer (or tractor) the sensor is a part of, based on the ordering of the trailers with no additional input needed from the user. Thus, if the pressure sensor reporting the alert is in the third trailer subnetwork 314c, the user can be alerted that a tire of the third trailer 304c has low pressure. This avoids the need for the user to spend time checking the tires for the tractor 302 or the other trailers 304a-b. This can be similarly used for readings and alerts for other known sensors as are known in the art.

It is also envisioned that the dollies 306 can have wireless hubs that form separate subnetworks rather than part of the trailer subnetworks 314b-c, respectively. In this instance, the dolly subnetworks would be similarly identified and ordered in the method of ordering the subnetworks. The process described herein can use shared specifications for standardized information. The shared specifications allow the process of linking trailers to the VAN 101, 301 and ordering the trailers to be easily carried out across multiple truck and trailer brands.

Preferably, no secondary user action is required to determine the ordering of the trailers 104,

304. For example, the method for ordering the trailers 104, 304 can be activated upon making the electrical and/or pneumatic connections between the tractor 102, 302 and the trailers 104, 304, as well as between the trailers 104, 304. The method can also be triggered by using the smart device 275.

SUSPENSION SYSTEM

Referring to Fig. 7, the technology described herein is presented in the context of vehicle 1000. However, the technology is applicable in any appropriate context, including with vehicles 100 and 300, and with types of vehicles other than those shown. In this example, vehicle 1000 is a tractor trailer vehicle that connects detachable trailer 1001 containing enclosed cargo space to a tractor 1002. Tractor 1002 also includes a cabin 1004 that houses the driver. Fig. 8 shows part of an underside of vehicle 1000, particularly some components of an example suspension system for vehicle 1000. The suspension system is an air suspension system in this example. An air suspension system uses air springs to absorb forces during movement.

In this example, the air springs in the air suspension system are implemented using a flexible bellows 1017, or simply“bellows”. Prior to operation, air is pumped into bellows 1017. The air pumped into bellows 1017 pressurizes and inflates the bellows 1017, causing chassis of vehicle 1000 to raise relative to its axle 1016, which may be a front axle, a rear axle, or any axle in between. As vehicle 1000 moves during driving, a piston 1028 receives forces transferred from axle 1016 of vehicle 1000 caused, for example, by bumps or other disturbances in the road. In response, piston 1028 moves up and down against bellows 1017. Bellows 1017 compresses in response to movement of piston 1028, thereby reducing the effects of those forces on tractor 1002 and/or trailer 1001. Bellows 1017 may be part of an assembly that is replicated several times in the suspension system, as described herein.

Fig. 8 shows examples of two assemblies 1014, 1015 included in a suspension system, with one assembly being on each end of vehicle axle 1016 proximate to a wheel (not shown). As shown in Fig. 8, each assembly 1014, 1015 includes a bellows 1017, 1018 that attaches to a chassis 1032 of vehicle such as vehicle 1000 as shown in a different example in Fig. 11. Each assembly 1014, 1015 also includes a leaf spring 1019, 1020 that attaches the bellows' piston 1028, 1029 to a respective bracket 1021, 1022, which is also attached to the chassis. In some implementations, the axle may be part of an assembly that includes a housing such as 1037 of Fig. 9, in which the axle rotates. Each leaf spring 1019, 1020 may also be attached to the axle via a corresponding mechanical coupling 1024, 1025. Each leaf spring 1019, 1020 may be a flexible member that is made of or includes metal or other appropriately-flexible material and that is flexible relative to bellows 1017, 1018 and corresponding bracket 1021, 1022. Fig. 9 shows the configuration of assembly 1014 in side view noting that Fig. 10 is a truck and Fig. 9 is a trailer, but the principle is the same.

As shown in Fig. 9, bellows 1017 includes a housing 1023. Housing 1023 attaches to the chassis of the vehicle at its top 1026, as explained above. Housing 1023 is a flexible air-tight container that holds pressurized air. Bellows 1017 also contains a channel 1027. A piston 1028 fits at least partly within channel 1027 and is configured to move within channel 1027 against bellows 1017.

In operation, piston 1028 is forced against bellows 1017, which compresses and absorbs the force. For example, forces produced through bumps in a road or other disturbances that occur during driving may be transferred from the wheels to axle 1016. Those forces are then transferred to leaf spring 1019, which flexes in response. This flexure causes piston 1028 to move against bellows 1017 within channel 1027. The pressure of the air within bellows’ housing 1023 may affect the amount of force that piston 1028 must apply to move. For example, greater air pressures in bellows 1017 may produce a stiffer suspension in that greater amounts of force may be required to move piston 1028 against bellows 1017. In contrast, lower air pressures in bellows 1017 may produce a softer suspension in that lesser amounts of force may be required to move piston 1028 against bellows 1017. Movement of piston 1028 against bellows 1017 in the presence of air pressure within bellows 1017 causes at least some force to be absorbed, producing a smoother ride.

In some implementations, the air suspension system may also include bellows arranged in a different configuration than that shown in Figs. 8 and 9. For example, bellows may be located on the underside of the vehicle, on both sides of a vehicle axle, or at any other appropriate location for absorbing forces while the vehicle is moving. In an example, Figs. 10 and 11 show components 1033 of an example air suspension system containing two pairs of bellows 1030, 1031 (only a single bellows 1030 is visible in Fig. 10) and shock absorber 1274. Fig. 12 is an upside-down view relative to Fig. 10. Each pair of bellows 1030, 1031 is interconnected by a respective spring lever 1034, 1035 (only a single spring lever 1035 is visible in Fig. 10). Each spring lever may be a flexible member made of metal or any other appropriate material that flexes, at least in part, in response to applied force. As shown in Figs. 10 and 11, a bellows 1030, 1031 is connected to each side of axle 1036 proximate to each wheel (not shown).

Referring to Fig. 12, the housing of each bellows 1030 is attached to chassis 1032 of the vehicle. Spring lever 1034 is mechanically coupled to axle housing 1337. Bellows 1030 of Figs. 10-12 may have a configuration that is similar to that described above with respect to Fig. 9. For example, referring to Fig. 12, example bellows 1030 may include a housing 1038, a channel 1043, and a piston 1046 that fits within, and moves at least partly within, channel 1043 against bellows 1030. Piston 1046 is connected to spring lever 1034 in this example. In response to force applied to spring lever 1046 during driving caused by road bumps or other disturbances for example, piston 1046 moves within the channel against bellows 1030, thereby absorbing at least some of the force.

Fig. 13 shows an example bellows piston 1039 connected to a leaf spring 1040; and Fig. 14 shows a close-up view of piston 1039. Piston 1039 of Fig. 13 may be the same as piston 1028 of Fig. 9; and leaf spring 1040 may be the same as leaf spring 1019 of Fig. 9. As explained previously and shown in Fig. 9, an example bellows 1017 includes a housing 1023 that has an upper end 1026 configured to connect to chassis and a lower end 1048 configured to connect to a leaf spring of the vehicle suspension system. Referring also to Figs. 15 and 16, the bellows piston 1039 - also referred to as the piston assembly - includes a piston housing 1042, which is viewed from the direction of arrow 1041 of Fig. 14. Fig. 15 shows the piston attached to leaf spring 1040 and Fig. 16 shows the piston housing 1042 independent of leaf spring 1040.

Referring to Figs. 17 and 18, piston housing 1042 forms a first central channel 1044 and an internal cavity 1045 proximate its lower end and in fluid communication with first central channel 1044. As shown in Figs. 13 and 14, a top plate 1047 is held within an upper portion 1052 of cavity 1045 by a first bolt 1049 extending through a mounting hole 1190 of the top plate. Mounting hole 1190 is countersunk to enclose a bolt head 1191 of first bolt 1049. First bolt 1049 threads into the first central channel 1044 to secure top plate 1047 to piston housing 1042.

Referring to Fig. 16-20, a sensing element 1050 - also referred to as a sensing device - is positioned within internal cavity 1045 below top plate 1047. Referring also to Fig. 21, in this example, sensing element 1050 includes an upper flange 1051 having an outer ridge 1263 in contact with the top plate 1047 such that the upper flange 1051 flexes in response to an applied force, such as a vehicle load. The sensing element 1050 has an ample relief area 1264 to allow for the flexing.

As shown in Fig. 20 to 23, 24, and 25, sensing element 1050 includes a lower

hexagonally shaped end 1055 that is configured to be put in place by a wrench or other tool. As shown in Figs. 24 and 25, multiple strain gauges 1057 are mounted on a top surface 1061 of sensing element 1050 to measure flexure of the upper flange 1051.

In Fig. 25, strain gauges 1057 are also depicted separately from top surface 1061 of the sensing element for clarity. As shown in Fig. 24, a printed circuit board (PCB) 1058 is electrically connected to strain gauges 1057. PCB 1058 is configured to receive signals from strain gauges 1057 that are indicative of strain and to send those signals to a central processor, such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein. In some implementations, PCB 1058 may include electronics for processing those signals locally. For example, the signals may be amplified, filtered, and/or packetized on PCB 1058 prior to sending the signals to the central processor. As shown in Figs. 19-22 a wireless transmitter module 1066 module may connect to PCB 1058 to implement signal transmission.

Referring to Fig. 14, along with Figs. 20-24, a lower second bolt 1059 extends through leaf spring 1040 and into a third central channel 1060 formed in the sensing element 1050 to secure leaf spring 1040 to sensing element 1050. When assembled, sensing element 1050 is held in internal cavity 1045 (Figs. 17 and 18) with the top plate 1047 pressing against an outer ridge 1092 and leaf spring 1040 supporting the sensing element 1050 from below.

As shown in Figs. 23 and 24 sensing element 1050 may also have an axial guide slot 1064 to enable mating with piston 1039 (Fig. 14) and to prevent rotation of the sensing element 1050 within piston housing 1042. Top plate 1047 may also have an inner collar (not shown) that mates with sensing element 1050 for additional structural support. Top plate 1047 also contains a rim or overload hardstop 1065 that forms a small gap with the sensing element 1050. In case of overload, the rim 1065 contacts the sensing element 1050 by which the force is directly going to the leaf spring 1040 and not thru the flexing membrane on which the strain gages 1057 are placed.

To remove lower second bolt 1059, service personnel can use a wrench on the hexagonally shaped end 1055 to hold sensing element 1050. Thus, sensing element 1050 and top plate 1047 can be easily accessed for replacement. DIAMOND WHEATSTONE BRIDGE

Fig. 26 is a circuit diagram showing an example strain gauge configuration 1070 that may be mounted on or near top surface 1061 of sensing element 1050 as shown in Fig. 25. Strain gauge configuration 1070, however, is not limited to use in the environments described herein and may be used in any appropriate technological context. Common elements included in a strain gauge such as buffers, amplifiers, wire bonds, and the like are omitted from the figures.

The strain gauge configuration includes a Wheatstone bridge formed from eight half bridges (or branches) in series and in parallel with one full Wheatstone bridge. In an example, a Wheatstone bridge is a circuit configuration including resistors that may be usable to determine an unknown resistance by comparing the unknown resistance with known resistances.

By way of example, Fig. 27 shows a standard Wheatstone bridge 1072. In this example, resistances R2 and R4 are fixed, R1 is variable, and R3 is unknown. The unknown resistance may be determined by balancing resistances across circuit branches 1093-1094 and 1095-1096 connected in a bridge network configuration. To balance the Wheatstone bridge 1072, an input voltage 1073 is applied. Currents through the two branches 1093-1094 and 1095-1096 produce a voltage difference 1074 across nodes 1097, 1098 of the bridge network if the currents (i) through branches 1093-1094 and 1095-1096 are not equal. The voltage difference (V) 1074 between nodes 1097, 1098 of Wheatstone bridge 1072 is measured. The variable resistance R1 is then adjusted until that voltage difference between nodes 1097, 1098 reaches zero. At that point, the Wheatstone bridge 1072 is balanced. The unknown resistance R3 can then be determined based on the known values of the other resistances, R1, R2, and R4.

In the example of Fig. 26, strain gauges 1057 having resistances that vary with applied strain are connected in a diamond Wheatstone bridge configuration. For example, the strain gauges 1057 may each include one or more variable-resistance resistors labeled“R _n ”, where“n” is a subscript varying from 1 to 16. Referring also to Fig. 25, example strain gauges 1076 are shown, along with their places in branches 1084, 1087 of the Wheatstone bridge configuration. In response to applied strain, the resistors' resistance values change. For example, the resistance values may increase or decrease in response to applied strain. The values of the resistors may be determined and used to calculate the average strain on each of the strain gauges as described herein. In the example of Fig. 26, Wheatstone bridge configuration 1077 includes eight branches 1080, 1081, 1082, 1083, 1084, 1085, 1086, and 1087. Branches 1080 and 1081 are connected in parallel with branches 1084 and 1085; and branches 1082 and 1083 are connected in parallel with branches 1086 and 1087. In this example, each branch, such as branch 1080, includes two strain gauges 1090, 1091 connected in series, all or some of which include a variable resistor or an equivalent variable-resistance circuit. Such a strain gauge thus has a resistance that varies in response to applied strain.

The voltage across the center 1095 of the bridge network is measured from Vp to Vm. One terminal 1094 of the Wheatstone bridge configuration 107 is connected to voltage source Vs and another terminal 1095 of the Wheatstone bridge configuration is connected to an electrical reference, such as electrical ground (GND).

As noted, the output of the bridge network of Fig. 26 is in first order (first order Taylor expansion) the average strain experienced by each of the strain gauges. The average strain

can be determined as follows:

where

As explained, a strain sensor may be placed under the bellows of a trailer, for example, between the part of the bellows that holds air and the piston. Due to up and down movement of the trailer, large parasitic moments occur, which may be up to 150 Nm for example. In order to detect the influence of parasitic loads, example Wheatstone bridge configuration 1077 includes strain gauges 1057 connected in a bridge configuration. Output terminals Vp and Vm may be connected to a single application-specific integrated circuit (ASIC) in some implementations. In this example, only one ASIC is used; however, that is not a requirement. The ASIC (not shown) may reside on PCB 1058 and may be used to analyze the measured strain and/or to report information such as the measured strain or analyses thereof to a central processor, such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein. The reporting may be performed over a direct wired connection or wirelessly over a vehicle area network. For example, the reporting may be performed using wireless transmitter module 1066. In some implementations the ASIC may be configured to take action in response to the measured strain. For example, the ASIC may adjust the stiffness of the suspension by pressurizing or depressurizing the bellows. The increasing and decreasing strain gauges of different half bridges“shake hands” within a single branch, such as 1080. First order Taylor development shows that the output of Wheatstone bridge 1077 is the average of all the half bridge outputs. Thus, Wheatstone bridge 1077 integrates the strain seen by the gauges 1057. In this example, the effective resistance Rb of the complete bridge is Rb=R0=4. Current consumption therefore may be the same as a standard microfused strain gauge (MSG) bridge having two half bridges. Three or more rings can be added to Wheatstone bridge 1077 to achieve the same integration effect but with lower total resistance of Wheatstone bridge 1077. Accuracy may be improved by utilizing four half bridges as compared with two half bridges. For example, four half bridges in series with one full bridge may yield the same results as the average of the outputs of two separate full bridges.

Increasing and decreasing gauges of different half bridges may be located within a single branch of the bridge. In this example, effective resistance Rb of the complete bridge is Rb= 2* R0.

Thus, there is two times less current consumption than in a standard bridge that has Rb=R0.

In another application, strain gauges in the Wheatstone bridge configuration shown in Fig. 26 may be used on a lever arm that has a non-uniform surface. This creates non-uniform strain fields within the sensor. As was the case above, accuracy may increase when two half bridges, four half bridges, eight half bridges, or the like are used. In short, the more half bridges that are used, the better the integrating effect of the strain gauge. In this regard, the strain sensor of Fig. 26 is not limited to using strain gauges shown in the configuration of Fig. 26. For example, in some implementations, the outer eight strain gauges of Wheatstone bridge 1077 can be omitted. In some implementations, an additional ring of eight strain gauges may be added to Wheatstone bridge 1077, resulting in a total of twenty-four strain gauges. An example of such an implementation is shown in Fig. 28. In general, the more strain gauges, which are represented by“R” in Fig. 28, that are included in the Wheatstone bridge, the more accurately the measurements produced will be.

SUSPENSION WITH LEAF SPRINGS AND SHACKLE

One or more leaf springs may augment the bellows-based air suspension system described herein. The leaf springs may be configured to provide support for the vehicle and to reduce the effect of bumps or other disturbances during movement. Leaf springs also may be used in the vehicle's suspension system to control a height at which the vehicle rides and to maintain alignment of tires to the road during driving. In an example, a leaf spring includes pieces of steel or other appropriately-flexible material that are attached together to create a flexible reinforced structure. The leaf spring may then be coupled, for example, to both a steer (or other) axle and a chassis of the vehicle to provide support for weight that is added to the vehicle. In some implementations, the leaf spring may protect the axle from damage in response to excessive weight added to the vehicle. In some implementations, one or more leaf springs may be used on a vehicle containing a non-air-based suspension system.

Figs. 29 and 30 show components 1100 of an example part of a vehicle's suspension system that employs two leaf springs 1101, 1102. The two leaf springs 1101 and 1102 are attached across (for example, perpendicularly) to steering axle 1104 of the vehicle and are attached to chassis 1105 of the vehicle and in parallel with chassis 1105 of the vehicle. In this example, sides 1106 and 1107 of the suspension system are identical in structure and function. Side 1107 shown in Fig. 30. Since the components of both sides 1106 and 1107 are identical, they are labeled using identical reference numerals, except for the leaf springs. In this regard, as shown in the figures, leaf spring 1101 (and leaf spring 1102) is attached to chassis 1105 via a pivot connector 1109, or simply“pivot”, and via a pair of shackles 1125 (which includes shackle 1110), both of which are described in more detail below. Thus, steering axle 1104 is connected to chassis 1105 via leaf spring 1101, 1102 which connects to chassis 1105 via pivot connector 1109 on one location and via shackles 1125 connected by bolts 1122 at another location.

Example pivot connector 1109 is fixedly coupled to chassis 1105 at a location of chassis 1105 and at a top portion 1199 of pivot connector 1109, while the lower portion 1200 of the pivot is rotatably connected to an end 1121 of leaf spring 1101. In addition to these structures, a connection member 1111 - in this example, a piston - is attached to both chassis 1105 and steering axle 1104. In response to force applied in the direction of arrow 1113, connection member 1111 compresses, thereby reducing the effect of bumps or other disturbances, including those having a lateral component. A mechanical coupling 1115 connects leaf spring 1101 to steering axle 1104.

In the preceding example, steering axle 1104 is the front wheel axle of the vehicle. Steering axle 1104 runs laterally across the vehicle between two tires and is connected to two separate support members of the chassis at opposing sides of the steering axle, as described previously. Accordingly, the sides of the suspension system are substantially symmetrical around the center of the steering axle, as noted above. In this example, shackle 1110 is configured for use in with any appropriate chassis including the chassis for a large vehicle such as vehicles 100, 300, 1000. An example suspension system, such as that shown in Figs. 29 and 30, may include four such shackles 1110 - that is, two pairs of shackles - per connection.

Fig. 31 shows front and back views 1119 and 1120, respectively, of example shackle

1110. As shown, shackle 1110 may be attached using bolts 1122. The shackle may also include rubber bushings 1123. An example shackle pairing 1125 that may be used in the configuration of Figs. 29 and 30 is shown in more detail in Fig. 32. In this example, shackle pairing 1125 includes two shackles 1110, 1129 connected together using fasteners 1122, such as bolts. In Fig. 32, shackle pairing 1125 connects on opposite ends of bolts 1122. In the example of Figs. 29-31, the first bolt 1122b rotatably connects the shackle pairing 1125 to a leaf spring 1101 while the second bolt 1122a connects the shackle pairing 1125 to chassis 1105. For example, the second bolt 1122a may rotatably connect the shackle pairing 1125 to chassis 1105.

When a vehicle load is applied to chassis 1105, the load is applied directly to chassis 1105 through a connecting member 1111, and also through the corresponding leaf spring 1101 via connections to the pivot 1109 and shackle pair 1125. As shown in Fig. 29, a vehicle load can result in a first moment distance (L1) between the connection of shackle pair 1125 to chassis 1105 (i.e., the first bolt) and pivot connection 1109. The vehicle load can result in a second moment distance (L2) between the area where the connecting member 1111 connects steering axle 1104 to the chassis and the area of chassis 1105 connected to pivot connection 1109. The first moment distance L1 between the first bolt 1122b and first pivot connection 1109 may be substantially twice the second moment distance L2. For example, the first moment distances L1 may be within 10% of twice the second moment distance L2.

Referring to Figs. 33-37, example shackle 1129 includes, on its front face 1213, a central cavity 1133 between bolt holes 1135, 1136 for connecting shackle 1129 using bolts. In some implementations, cavity 1133 extends to a depth that is substantially (for example, (+/- 10%) half-way through the entire width of shackle 1129. In some implementations, cavity 1133 extends to a depth that is 10% through shackle 1129, 20% through shackle 1129, 30% through shackle 1129, 70% through shackle 1129, 80% through shackle 1129, or 90% through shackle 1129. A strain gauge 1141, examples of which are described herein, may be embedded within the center of cavity 1133, and thus, within a central location of the shackle in all directions (e.g., the“r” and“t” axes 1138 of Figs. 35-37 as well as in the direction of the cavity depth). In some situations, the central placement of strain gauge 1141 and the configuration of shackle 1129 - for example, the central placement of cavity 1133 within shackle 1129 and the depth of the cavity 1133 about half-way through shackle 1129 - may help to reduce parasitic forces through shackle 1129 that may affect the strain gauge measurements. The depth of the cavity is chosen such that it is located at the neutral bending plane.

In some implementations, such as that shown in Figs. 33 to 37, cavity 1133 has a bow- like shape. For example, referring to Figs. 36 and 37, the bow-shaped design of cavity 1133 may include a narrow center 1235 between wider opposing ends 1136 closest to bolt holes 1135, 1136. In some situations, the bow-shaped design of cavity 1133 helps to reduce unwanted forces on strain gauge 1141.

As shown in Fig. 34, shackle 1129 also includes, on its back face 1237, parallel channels 1140 running adjacent to the cavity 1133 and extending in a longitudinal direction between the bolt holes 1135, 1136 of each shackle 1129. The parallel channels 1140 may be on an opposite back face of the shackle 1129 than cavity 1133, as shown in Figs. 33 and 34. Accordingly, the parallel channels 1140 form slots in a back face 1237 of the shackle 1129 that are opposite front face 1213 within which cavity 1133 is formed. In some situations, parallel channels 1140 may also help to reduce unwanted strain on strain gauge 1141.

SHACKLE CALIBRATION

When shackle pairings, such as shackle pairing 1125, are placed on a vehicle suspension system, strain gauges 1141 (Figs. 35 to 37) on each of the four shackles (two shackle pairings) measure strain through a respective shackle 1129. The four strain gauge readouts from the shackle can be used to determine a load on the chassis. For example, a central processor, such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein may obtain the strain gauge readouts via a direct wired connection or wirelessly over the vehicle area network. The central processor may use the four strain gauge readouts, along with other information in some cases, to determine the load on the chassis.

The positioning of the shackle pairings 1125, including the corresponding moment distance L1 relative to the moment distance L2, can be used to calibrate shackles 1129 before the shackles have been fitted to the suspension system of the vehicle. For example, the shackles 1129 can be connected in shackle pairings 1125 in a testing environment that mimics a real world shackle pairing such as that shown in Fig. 29. A test force 1144 can then be applied to each shackle pairing 1125 through upper bolt 1122a as shown in Fig. 38. Each strain gauge 1141 in each shackle cavity 1133 will generate a sensor reading in response. The shackles 1129 may be calibrated for an expected vehicle load based on a first sensor reading from a first sensor on one shackle 1129, a second sensor reading from a first sensor on another shackle 1129, the test force, and a ratio of a first moment distance to a second moment distance.

Since the ultimate positioning of the four shackle pairings 1125 within the vehicle suspension system is known, the expected strain on the shackle pairings 1125 can be calculated based on the known moment distances from the vehicle load and at the strain gauges 1141. For example, all strain gauges 1141 can be positioned to produce the moment distance L1 described above with respect to a bolt 1238 attaching a leaf spring 1101 to a pivot connection 1109. The second moment distance L2 can also be the same on both sides of chassis 1105, representing the moment distance between the steering axle's direct connection to chassis 1105 and the chassis connection to the pivot connection 1109. Once the shackle pairings 1125 are in place on the vehicle suspension, the most accurate sensor readout can be obtained by summing the readouts of all four strain gauges 1141. This allows for offsetting of sources of error, including parasitic forces affecting the strain gauge measurements. Therefore, strain gauges 1141 may be calibrated to determine an expected vehicle load based on the sum of all four strain gauge readouts. In some examples, the calibration may be based on test forces used during testing, the sensor readings, and the ratio of the moment distances L1 :L2 for each strain gauge pairing and respective steering axle connection to the chassis.

Referring to Fig. 39A and 39B, other example calibration processes are presented below, starting with definitions of terms. These example calibration processes may include determining loads on vehicle axles and wheels based on strain gauge measurements obtained from the shackles and other information set forth below.

Height:

Bellow loadcells + shackles:

Height:

Bellow loadcells + shackles:

EDDY CURRENT SENSOR ON LEAF SPRING

One or more contactless sensors of various types can be placed at various locations within a vehicle suspension system for measuring vehicle loads, as described in more detail below. The sensors can include, but are not limited to, a magnetic rotation sensor and an eddy current sensor.

Referring to Figs. 40-42, an example load sensing system including an eddy current sensor 1150 is shown. An example eddy current sensor 1150 uses induced eddy currents to sense displacement in a conductive structure. For example, deformation of the structure causes a circulating flow of electrons, or currents, within the structure. These circulating currents create electromagnets having magnetic fields that oppose the effects of an applied magnetic field.

These magnetic field is detected in order to detect displacement of the structure.

An eddy current sensor 1150 may be incorporated onto a flexible leaf spring 1151 such as those shown in Figs. 40 to 42. Similar to the other suspension systems described herein, the components of a vehicle suspension system 1154 of Figs. 40 to 42 include leaf spring 1151 and a wheel axle 1156 (shown schematically). The wheel axle 1156 can be, for example, a steering axle and can connect to a chassis (not shown) as otherwise shown and described herein. The eddy current sensor 1150 may be configured to sense the displacement (for example, the delta) between a bracket 1157 and an adjacent location of leaf spring 1151. In some cases, bracket 1157 can be attached directly to leaf spring 1151 at a first location 1158 proximate axle 1156.

Example bracket 1157, as is the case with other brackets used to implement the sensors described herein, may be made of a material that is substantially inflexible. At the first location 1158, there is little deflection of leaf spring 1151, even when a large vehicle force is applied (see, e.g., Fig.

42 showing little deflection of leaf spring 1151 at location 1158). However, at a second location 1159 of bracket 1157 farther from axle 1156, there will be a greater deflection of leaf spring

1151 when a large enough vehicle load is applied (see, e.g., Fig. 42 showing greater deflection of leaf spring 1151 at location 1159). The eddy current sensor may be calibrated beforehand for a particular vehicle. Then, the vehicle load may be determined based, at least in part, on the leaf spring deflection measured by eddy current sensor 1150. For example, a central processor, such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein may obtain the signal from sensor 1150 via a direct wired connection or wirelessly over the vehicle area network. The central processor may use the sensor readouts, along with other information in some cases, to determine the vehicle load on the chassis and other information as appropriate. In addition, it may be obvious to person skilled in the art that also other types of displacement sensors like optical sensors may be used.

CONTACTLESS SENSOR ON AN AXLE

Figs. 43, 44, 45, and 46 show another example of a load sensing system that includes a contactless sensor 1160 that is usable with components of a vehicle suspension system. The contactless sensor 1160, which is shown in Fig. 46 in block form, is configured to measure the deflection of axle 1161 with respect to bracket 1162. The contactless sensor 1160 is similar to the sensor described with respect to Figs. 40 to 42 except that, in the case of contactless sensor 1161, bracket 1162 is fixed to wheel axle 1161 (e.g., the steering axle) rather than to a leaf spring. In this example, bracket 1162 is directly adjacent to axle 1161 and can be fixedly attached to axle 1161 near a center location 1164 of axle 1161.

The contactless sensor 1160 can measure a displacement distance between bracket 1162 and wheel axle 1161 at a second location 1165 that is distal from - for example, away from - center location 1164 and closer to axle end 1242. As above, at center location 1164 of the axle 1161, there is relatively little movement relative to bracket 1162 and, therefore, bracket 1162 continues to extend along a relatively static plane even when wheel axle 1161 is stressed.

On the other hand, axle 1161 flexes at locations farther from the center location 1164. Therefore at the farther second location 1165, a change in a distance - for example, a gap (not shown in the figures) - between bracket 1162 and wheel axle 1161 can be detected and the dimensions of the gap measured. Sensor 1160 can be calibrated to identify a vehicle load based on the change in distance. A central processor, such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein may obtain the sensor readouts via a direct wired connection or wirelessly over the vehicle area network. The central processor may use the sensor readouts, along with other information in some cases, to determine the vehicle load on the chassis and other information as appropriate.

Figs. 47 and 48 show another example load sensing system that includes one or more contactless sensors 1170, 1171 that are usable with components of a vehicle suspension system. Notably, while two sensors 1170, 1171 are shown in this example, only one sensor may be used or more than two sensors may be used. Each contactless sensor 1170, 1171 can be an eddy current displacement sensor, as described herein.

A sensor bracket 1172 holds a second bracket 1173 in a fixed position directly adjacent to a sloped end portion 1244 of the steering axle 1174. The second bracket 1173 holds sensors 1170, 1171 at a position offset from sloped end portion 1244 of steering axle 1174. As noted, sensors 1170, 1171 can be eddy current sensors, or other contactless sensor types, and are configured to identify movement based on a distance between the sensor and the steering axle. When the vehicle is loaded, steering axle 1174 will be urged to flex upward, toward sensors 1170, 1171. Thus, the load on the vehicle will cause a change in the distance between sensors 1170, 1171 and sloped end portion 1244 of the steering axle 1174. Sensors 1170, 1171 are calibrated to measure the vehicle load based on the change in distance. A central processor, such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein may obtain the sensor readouts via a direct wired connection or wirelessly over the vehicle area network. The central processor may use the sensor readouts, along with other information in some cases, to determine the vehicle load on the chassis and other information as appropriate.

Fig. 49 shows another contactless sensor 1175 for use with components of a vehicle suspension system. The vehicle suspension system includes a chassis 1250, rubber buffers 1252, a shackle 1253, a clamped area 1254, a bent axle 1255, a steering center 1256, a front eye center 1257, a steering lever 1258, a leaf spring 1259, and wheel joint 1260. The contactless sensor 1175 in this case is a magnetic rotation sensor, which is shown in block form. The magnetic rotation sensor 1175 is attached to chassis 1270 of the vehicle, to the steering axle, or to a mechanical coupling to the steering axle, and is configured to measure a deflection distance of the leaf spring to determine a vehicle load. A central processor, such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein may obtain the sensor readouts via a direct wired connection or wirelessly over the vehicle area network.

The central processor may use the sensor readouts, along with other information in some cases, to determine the vehicle load on the chassis and other information as appropriate.

VEHICLE AREA NETWORK

Referring back to Fig. 39, schematic and overhead views of a vehicle are shown. In this example, vehicle 1261 is a tractor trailer vehicle having a communication hub operatively connected to a plurality of weight sensors and to the various sensors as described herein, for example with respect to Figs. 1 and 5. As previously described, the communication hub may be or include a computing system containing one central processors, examples of which are described herein. The connections may be wired or wireless and as many sensors as needed may be utilized with one or more communication hubs. Depending upon the placement and function of each weight sensor, various different weight sensors may be used. Additionally, the communication hub may be connected to different types of sensors such as pressure sensors, temperature sensors, oxygen sensors, or the like, as needed in automotive applications. For example, the front axle weight sensor may be integral with a shackle (e.g., see Figs. 29 and 30), whereas the other sensors may include strain gauges as described herein. Kingpin load measurements, load cells, pressure sensors and all manner of sensor data may be provided into the communication hub for central processing by the hub and/or by a remote command center in communication, such as by satellite, with the communication hub.

Fig. 50 shows an example of a vehicle area network (VAN) located on a vehicle as described herein, for examples, with respect to Figs. 1 and 5. The VAN includes one or more central processors 1180 such as the micro controller of Fig. 2B, an external computer, or other example processing devices described herein. The central processors 1181 communicate with various sensors including, but not limited to, those described herein. For example, the sensors may transmit readings sporadically, intermittently, periodically, or continuously to the central processors 1180. The central processors may use those readings to determine vehicle conditions and may, in some cases, take appropriate action. The central processors may also transmit information to the sensors, for example, to calibrate or query the sensors. In some

implementations, readings may be output to a display device that is located on the vehicle or at a remote facility. Users may interact with the sensors via the display device and an input device.

The example systems described herein may be implemented by, and/or controlled using, one or more computer systems comprising hardware or a combination of hardware and software. For example, a system like the ones described herein may include various controllers and/or processing devices located at various points in the system to control operation of the automated elements. A computer may coordinate operation among the various controllers or processing devices. The computer, controllers, and processing devices may execute various software routines to effect control and coordination of the various automated elements.

A computing device may include a graphics system, including a display screen. A display screen, such as an LCD or a CRT (Cathode Ray Tube) displays, to a user, images that are generated by the graphics system of the computing device. As is well known, display on a computer display (e.g., a monitor) physically transforms the computer display. For example, if the computer display is LCD-based, the orientation of liquid crystals can be changed by the application of biasing voltages in a physical transformation that is visually apparent to the user. As another example, if the computer display is a CRT, the state of a fluorescent screen can be changed by the impact of electrons in a physical transformation that is also visually apparent. Each display screen may be touch-sensitive, allowing a user to enter information onto the display screen via a virtual keyboard. On some computing devices, a physical QWERTY keyboard and scroll wheel may be provided for entering information onto the display screen. Each computing device, and computer programs executed thereon, may also be configured to accept voice commands, and to perform functions in response to such commands.

The example systems described herein can be controlled, at least in part, using one or more computer program products, e.g., one or more computer program tangibly embodied in one or more information carriers, such as one or more non-transitory machine-readable media, for execution by, or to control the operation of, one or more data processing apparatus, e.g., a programmable processor, a computer, multiple computers, and/or programmable logic components.

A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a network. Actions associated with implementing all or part of the systems described herein can be performed by one or more programmable processors executing one or more computer programs to perform the functions described herein. At least part of the systems can be implemented using special purpose logic circuitry, e.g., an FPGA (field programmable gate array) and/or an ASIC (application-specific integrated circuit).

Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only storage area or a random access storage area or both. Elements of a computer (including a server) include one or more processors for executing instructions and one or more storage area devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from, or transfer data to, or both, one or more machine- readable storage media, such as mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. Machine-readable storage media suitable for embodying computer program instructions and data include all forms of non-volatile storage area, including by way of example, semiconductor storage area devices, e.g., EPROM, EEPROM, and flash storage area devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

Any“electrical connection” as used herein may include a direct physical connection or an indirect connection that includes wired or wireless intervening components but that nevertheless allows electrical signals (including wireless signals) to flow between connected components.

Any“connection” involving electrical circuitry mentioned herein through which electrical signals flow, unless stated otherwise, is an electrical connection and not necessarily a direct physical connection regardless of whether the word“electrical” is used to modify

“connection”.

Elements of different implementations described herein may be combined to form other embodiments not specifically set forth above. Elements may be left out of the structures described herein without adversely affecting their operation. Furthermore, various separate elements may be combined into one or more individual elements to perform the functions described herein.

It will be appreciated by those of ordinary skill in the pertinent art that the functions of several elements may, in alternative embodiments, be carried out by fewer elements, or a single element. Similarly, in some embodiments, any functional element may perform fewer, or different, operations than those described with respect to the illustrated embodiment. Also, functional elements (e.g., modules, databases, interfaces, computers, servers and the like) shown as distinct for purposes of illustration may be incorporated within other functional elements in a particular implementation.

All patents, patent applications and other references disclosed herein are hereby expressly incorporated in their entireties by reference. While the subject technology has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the subject technology without departing from the spirit or scope of the invention as defined by the appended claims.