This application claims the benefit of priority under 35 USC § 119(e) of U.S. Provisional Patent Application No. 62/323,772 filed April 17, 2016, the contents of which are incorporated herein by reference in their entirety.

BACKGROUND

Vehicles may be weighed at fixed weigh bridges or on portable weigh pads, but these measurements are available only at the location of the weighing equipment. Vehicles may also be equipped with load cells and/or strain gauges installed in the vehicle underbody or on wheel hubs for automatic load detection. Load cells are known to be expensive and their design varies for different types of vehicles. Installing load cells often involves temporarily removing vehicle wheels, and welding fixtures into place. Vehicles that have suspensions may weigh themselves by monitoring deflection of suspension components such as springs.

One known application for automatic load detection systems is to monitor and track the navigational systems of bus, taxi, police, shippers, distributors, municipal waste collectors. Other known applications include monitoring if a pay load of a vehicle is within safety limits and providing weight input to an Autonomous Emergency Braking Assistant included in a vehicle.

SUMMARY

The disclosure in some embodiments relates to an automatic load detection system for a vehicle with tires that is both cost effective, easy to install and does not interfere with other systems in the vehicle. According to example embodiments, the system includes at least one sensor that senses a distance that varies based on compression of the tire under a load. In some example embodiments, the distance sensed is between a wheel rim or axle of the vehicle and a surface on which the vehicle is standing and is therefore not sensitive to activity of shock absorbers of the vehicle. In example embodiments, the system may determine load on one or more tires of vehicle. According to some example embodiments, the sensor may be applied to detect load on other objects including a compressible part that makes contact with a surface. The sensor may detect load based on sensing a change in distance to the surface that occurs when the compressible part is compressed under load.

According to some example implementations, there is provided a method for alerting a driver when a child has been left in the car based on detection with the automatic load detection system. According to some other example implementations, there is provided a method for monitoring goods or fuel theft based on detection with the automatic load detection system. In some embodiments, the automatic load detection system may be activated in response to a start command or a defined event and may monitor any changes in load until receiving an end command is received or until a defined event occurs.

According to an aspect of some example embodiments, there is provided an automatic weight detection system comprising: at least one distance sensor configured to be mounted on a wheel axle or wheel rim of a vehicle and to detect changes in a distance between a wheel rim of a wheel and a contact point a tire of the wheel with a platform on which the tire is standing; and a controller configured to determine a change in load on the vehicle based on the detected change in height.

Optionally, the distance sensor is configured to be mounted on an axle of the wheel and is configured to detect distance to the platform.

Optionally, the distance sensor is configured to detect time of flight of a signal transmitted by the sensor and reflected on the platform.

Optionally, the distance sensor is an ultrasound or an infrared (IR) based sensor.

Optionally, the distance sensor is a Doppler interferometer or laser triangulation sensor.

Optionally, the distance sensor is a camera that is configured to capture an image of the tire and to detect the distance based on a shape of the tire as captured in the image.

Optionally, the system includes a plurality of distance sensors, wherein the plurality of distance sensors are distributed along the wheel axle and wherein the controller is configured to detect a load distribution in the vehicle or a center of mass of the load based on output from the plurality of the distance sensors. Optionally, the at least one distance sensor is configured to be rotatably mounted on the wheel rim or a hub of one or more wheels of the vehicle.

Optionally, the system includes a plurality of distance sensors distributed along a circumference of the wheel rim.

Optionally, the plurality of distance sensors are configured to detect capacitances between electrodes incorporated in the distance sensors and a conductive layer of the tire.

Optionally, the conductive layer is conductive mesh embedded in tire.

Optionally, the conductive layer is placed over an inner surface of the tire. Optionally, the plurality of distance sensors include an LED and photo- detector pair and wherein the photo-detector is configured to detect reflection of the light emitted by the LED.

Optionally, the light is reflected off a reflective layer is positioned an inner surface of the tire.

Optionally, the controller is configured to selectively activate a portion of the plurality of distance sensors based on their orientation toward the platform.

Optionally, the controller is to identify a portion of the plurality of distance sensors facing the platform based on the output detected.

Optionally, the system includes a ring formed with non-conductive material, wherein the ring is mounted on the wheel rim and wherein the plurality of distance sensors is mounted on the ring.

Optionally, the controller is configured to retrieve data from a computer processing unit of a vehicle and to adjust the change in load detected based on the data.

Optionally, the data is pressure in a tire of the vehicle.

Optionally, the data is fuel consumed over a defined period.

According to an aspect of some example embodiments, there is provided a method for monitoring load in a vehicle, the method comprising: monitoring a distance between a wheel rim of a wheel and a contact point a tire of the wheel with a platform on which the tire is standing; detecting pressure in at least one tire; determining load based on comparing the pressure and the distance to pre-defined data; and reporting the load. Optionally, the method includes monitoring the distance at each of a plurality wheels; and determining a distribution of the load based on changes detected at each of the plurality of wheels.

According to an aspect of some example embodiments, there is provided an method for detecting that a passenger was left in a vehicle, the method comprising: monitoring status of a vehicle doors; monitoring status of a seatbelts in the vehicle; monitoring change in load in association with a change in status of the vehicle doors and a change in status of the seatbelts; determining that a passenger was left in the vehicle based on the change in the load is association with the change in association with the change in status of the vehicle doors and the change in status of the seatbelts; and providing at least one of a visual and a acoustic alert based on the determining that the passenger was left in the vehicle.

Optionally, the method includes monitoring the status of the seatbelts in the vehicle includes monitoring a status of a seatbelt of an auxiliary seat added to the vehicle for seating a child or infant.

Optionally, the change in load that is monitored is a change that occurs between a period in which a seatbelt of a driver has been unlocked and a predefined time period after a vehicle door of the driver has been shut.

Optionally, the method includes monitoring activation of an immobilizer of a vehicle, wherein monitoring change in the load is also association with the activation of the immobilizer and wherein the change in load that is monitored is a change that occurs between a period in which a seatbelt of a driver has been unlocked and the activation of the immobilizer.

Optionally, monitoring the change in the load includes monitoring changes in a center of mass of the load.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the disclosure, example methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS Some implementations are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the disclosure. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the disclosure may be practiced.

In the drawings:

FIG. 1 is a simplified drawing of an example distance sensor mounted on a wheel axle of a vehicle in accordance with some embodiments;

FIGs. 2A and 2B are schematic front and cross sectional views of an example wheel of a vehicle under low load in accordance with some embodiments;

FIGs. 3A and 3B are schematic front and cross sectional views of an example wheel of a vehicle under high load in accordance with some embodiments;

FIGs. 4 A and 4B are schematic drawings of example distance sensors integrated with wheel under low and high load in accordance with some embodiments;

FIG. 5 is a simplified block diagram of an automatic load detection system in accordance with some embodiments;

FIG. 6 is a simplified flow chart of an example method to detect load in a vehicle in accordance with some embodiments;

FIG. 7 is a simplified flow chart of an example method to monitor changes in load during transportation in accordance with some embodiments; and

FIG. 8 is a simplified flow chart of an example method to alert a driver that a child was forgotten in the vehicle in accordance with some embodiments.

DETAILED DESCRIPTION

According to some example implementations, automatic load detection system detects a distance between an axle or a wheel rim of a vehicle and a ground on which the vehicle is standing and relates that distance to load on the vehicle. According to some example implementations, changes in the distance are based on deformation compression of the tire, e.g. of a tread area on the tire under load. According to example embodiments, a distribution of load in a vehicle may be determined based on comparing load detection at a contact point of each of a plurality of wheels on the underlying surface. In some example embodiments, the automatic load detection system adjusts the information based on distance with additional parameters, e.g. air pressure of the tires, temperature, humidity, altitude and inclination of the vehicle. The additional parameters may be obtained by communication with a Computer Processing Unit (CPU) of the vehicle through a Controller Area Network (CAN) bus or via wireless communication. The present inventor has found that weight detection based on sensing distance between the axle or wheel rim and the ground is described herein is more direct durable and cost effective than other known detection methods, e.g. methods that are based on parameters related to shock absorbers of the vehicle. The sensors are also not typically sensitive to shock absorber wear out. Weight detected based on a position or strain on the shock absorbers may be sensitive to wear on the shock absorbers over time The sensor as described herein does not sustain the load of the vehicle and therefore may be substantially lower in cost than sensors that are required to sustain such load. Optionally, the vehicle may be retrofitted with the sensor without dissembling the vehicle.

In some example implementations, the automatic load detection system includes a sensor positioned on an axle of the vehicle and the sensor senses distance from the axle to the ground based on time of flight of a signal reflected from the ground. According to embodiments of the present invention, the distance measured is a direct measurement of compression of the tire under load and is not substantially affected by activity of the shock absorbers. Optionally, the sensor is a piezoelectric transducer sensor that is configured to emit and receive an ultrasound signal. Optionally, the sensor is a laser and photodiode pair configured to emit and receive a light signal. In some example embodiments, the sensor is a laser triangulation sensor as provided by Micro- Epsilon in Ortenburg, Germany. In other example implementations, the automatic load detection system includes an interferometer that senses distance based on reflection of an optical signal from the ground. In yet other embodiments, the sensor includes a camera that may be configured to detect the distance. In other example embodiments, the sensor may be a camera with processor that may detect distance based a captured image showing deformation of a portion of the tire touching the road. According to some other example implementations, the automatic load detection system includes a sensor integrated with the wheel rim and the sensor is configured to sense a distance between the rim and an inner surface of the tire. In some example implementations, the integrated sensor may be a capacitive based sensor that detects capacitance between an electrode rigidly fixed to the rim and conductive material on the tire. In some example implementations, the conductive material on the tire is a conductive layer, e.g. conductive mesh that may typically be part of the tire. In some example embodiments, the sensor includes an array of electrodes mounted around the rim and each of the electrodes is configured to capacitively couple with the conductive layer on the tire. In some example implementations, the automatic load detection system may be configured to selective activate electrodes facing a portion of the tire that is in contact with the ground. Optionally, all the electrodes may be activated and based on the outputs electrodes facing the underlying surface (the road) may be identified. Typically, the electrodes that indicate the shortest distance are the electrodes that are facing the road.

In other example implementations, the integrated sensor may be an optical based sensor for example and sensor that includes an array of Light Emitting Diodes (LEDs) and array of photodiodes mounted on the wheel rim and a reflective surface positioned on an inner surface of the tire. The photodiodes may sense reflection of light emitted by the LEDs and distance between the photodiodes and the reflected surface may be determined based on intensity of the light received by the photodiodes. In some example implementations, distance is associated with a shortest distance detected by the array of photodiodes. Optionally, the integrated sensor may be powered with a dedicated battery, a super capacitor, by magnetic coupling with a coil or by a magnetic field generated by rotation of the wheel.

According to some example implementations, there is provided a method for reminding a driver that a child is in the backseat of the vehicle or alerting the driver that the child might have been left in a vehicle. In some example embodiments, the automatic load detection system is configured to monitor weight distribution and associate changes in the weight distribution or changes in center of mass) with other parameters such as for example one or more of status of the doors, status of the seatbelts, outputs from various vehicle sensors, output from a camera installed in the vehicle to determine when a child might have been left behind in a vehicle. Based on the determination, the automatic load detection system may initiate an alert to the driver or the surrounding environment. The alert may be an acoustic alert or a visual alert, e.g. an alarm or blinking of the headlights. Typically, the amount of fuel that may have been consumed during travel is considered when detecting the change in weight or center of mass. Information regarding fuel consumption may be obtained from the CPU of the vehicle. Optionally, information obtained from vehicle sensors that detect malfunction of the vehicle, e.g. loss of water or oil may be considered when detecting change in weight or center of mass. Optionally, movement of an object in the vehicle may be detected A similar method may be applied to alert a driver when an object, e.g. a laptop was inadvertently left in the vehicle.

According to some example implementations, there is provided a method for monitoring goods or fuel theft based on detection with the automatic load detection system. In some example embodiments, the automatic load detection system is configured to monitor a change in weight in the vicinity of the fuel tank of the vehicle and provide an alert upon detecting a reduction in weight associated with the fuel tank while the vehicle is in a static state. Optionally, the automatic load detection system may initiate an alarm on the vehicle in response to detecting a fuel theft. Optionally, a rate of the weight change may be monitored and reported.

In some other example embodiments, the automatic load detection system is configured to monitor loading and unloading of goods that are transported with the vehicle as well as location of the loading and unloading. In some example embodiments, automatic load detection system compares weight related to loading and unloading to an electronic packing list that may be updated by a fleet manager or driver.

In other example embodiments, the automatic load detection system is configured to record a load profile on the vehicle over time and apply the accumulated data to evaluate how soon a tire of a car should be replaced or a shock absorber should be checked.

Reference is now made to FIG. 1 showing a simplified drawing of an example distance sensor mounted on a wheel axle of a vehicle in accordance with some embodiments. According to some example embodiments, a distance sensor 150 is attached to a wheel axle 120 of a vehicle e.g. with an attachment mechanism 155. Optionally, a sensor is positioned on the axle near a wheel. Optionally, a distance sensor 150 is positioned in proximity to a wheel 110 of the vehicle and detects distance to a road or platform 180 on which the vehicle is standing. Optionally, distance sensor 150 may be rotatably mounted on a wheel rim with a weight that is configured to orient the sensor toward ground 180. Distance 200 is not related to activity of shock absorbers in the vehicle and may be a direct measurement of compression of tire 130 and may vary linearly with respect to load over a large dynamic range Since distance 200 is not related to activity of shock absorbers in the vehicle, it is also not sensitive to wear on the shock absorbers. For example as the load on the vehicle increases, a tire 130 deforms (flattens) at contact area with road 180 and distance 200 may decrease. The degree of flattening is related to the amount of load applied on wheel 110 and/or axle 120 for a given temperature, tire pressure and tire condition.

According to some embodiments of the present invention, distance sensors 150 are ultrasound based sensors that measure time of flight of a signal 140 transmitted by sensor 150, reflected off platform 180 (signal 160) and then received by sensor 150. Optionally, distance sensor 150 may include one or more piezo ultrasound transducers. Alternatively, distance sensor 150 may be an InfraRed (IR) based sensor that detects distance to platform 180 based on time of flight of and IR signal. In some other example embodiments, distance sensor 150 may be Doppler interferometer. In yet example embodiments, distance sensor 150 is a camera that captures an image of a portion of tire 130 and rim 135 under axle 120 and detects compression based on a shape of tire 135. For example the camera may image bulging of the tire due to compression and based on the extent of the bulging detect compression of the tire. Bulging of the tire typically occurs on the sides of the tire that is oriented in a vertical direction with respect to the ground on which the tire is standing. The camera may be positioned at an angle with respect to the side of the tire so that the bulging may be visualized.

Reference is now made to FIGs. 2A and 2B showing schematic front and cross sectional views of an example wheel of a vehicle under low load and to FIGs. 3A and 3B showing schematic front and cross sectional views of an example wheel of a vehicle under high load all in accordance with some embodiments. According to some embodiments of the present invention, distance sensor 150 is configured to detect changes in height 201 between wheel rim 135 and a portion of tire 130 that is in contact with platform 180. As the load on axle 120 of the vehicle is increased, tire 130 and the air 170 between rim 135 and tire 130 decreases. This flattening is detected by sensor 150 as a decrease in distance 200. Since tire 130 is the only deformable element between a height of sensor 150 and platform 180, any change in distance 200 may be attributed to flattening of tire 130. In other example embodiments, distance sensor 150 may be mounted on rim 135 or hub 137. When distance sensor 150 is mounted on rim 135 or hub 137, a change is distance detected may also be attributed to flattening of tire 130. Distance sensor 150 may be for example a laser triangulation sensor, an ultrasound sensor, an interferometer or a camera. In an embodiment when distance sensor 150 is a camera, the camera may capture an image of a portion of tire 130 and rim 135 under axle 120 and detect compression based on a shape of tire 135.

Reference is now made to FIGs. 4A and 4B showing schematic drawings of example distance sensors integrated with wheel under low and high load in accordance with some embodiments. According to some example embodiments, an automatic load detection system may include an array of distance sensors 250 mounted around a circumference of wheel rim 135 and may detect a distance to a layer 235 in tire 130. Optionally, a ring 255 is mounted on wheel rim 135 and array of distance sensors 250 are mounted on ring 255. Ring 255 may be formed with non conductive material and may provide for positioning sensors 250 closer to layer 235 and further from wheel rim 135 to strengthen capacitive coupling with layer 135 while weakening capacitive coupling with rim 135. Since wheel rim 135 rotates with respect to platform 180, an array of distance sensors 250 may be applied to detect distance 202 between a distance sensor 250 facing platform 180 and a portion of tire 130 that is in contact with platform 180. In some example embodiments, all the distance sensors 250 are activated to detect distance and load is determined based on sensors 250 that detect the shortest distance. The shortest distance will typically be distance 202' . Optionally interpolation is applied between a plurality of outputs from sensors 250 in case none of sensors 250 are directly facing platform 180. In other example embodiments, a control box 260 may detect sensors 250 facing platform 180 and may selectively activate distance sensors 250 facing platform 180. In some example embodiments, distance sensors 250 may be capacitive based sensors and layer 235 may be a conductive layer that is part of tire 130 (FIG. 4A) or may be dedicated layer applied on an inner surface of tire 130 (FIG. 4b). Distance 202 may be detected based on capacitive coupling between an electrode in sensor 250 and layer 135. Optionally, layer 235 may be a conductive mesh that may typically be integrated with tire 130. The capacitive coupling may be linearly related to distance 202. The dielectric coefficient (e.g. capacitance) may be correlated with temperature and air pressure of air 170 in tire 130.

In other example embodiments, distance sensors 250 may be pairs of LEDs and photo detectors and layer 235 (FIG. 4B) may be a reflective surface configured to reflect light from the LEDs and distance 202 may be detected based on intensity of light captured by the photo detectors of sensor 250. Intensity may be linearly related to distance 202.

According to some example embodiments, distance sensors 250 may be controlled by control box 260 mounted on chassis 280. Optionally, control box 260 includes a power supply that is configured to power sensors 250 as well as communicate with sensors 250 based on wireless transmission. In other example embodiments, a control box 260 may detect sensors 250 facing platform 180 and may selectively activate distance sensors 250 facing platform 180.

Alternatively, a distance sensor 250 may be rotatably mounted on hub 137 or rim 135 so that distance sensor 250 can freely rotate toward ground 180 due to gravity. Optionally, more than one distance sensor 250 may be rotatably mounted on hub 137 and the output from sensors may be interpolated or averaged.

Reference is now made to FIG. 5 showing a simplified block diagram of an automatic load detection system in accordance with some embodiments. According to some example embodiments an automatic load detection system 500 includes one or more distance sensors 150 and a controller 515. Controller 515 may typically have memory and processing capability. Optionally, some or all processing of output from the one or more distance sensors may be performed by a CPU of the vehicle. Automatic load detection system 500 may be powered by a battery of the vehicle or may include a dedicated power source and/or power management unit 505. In some example embodiments, automatic load detection system 500 may include additional sensors 510, e.g. temperature sensors, gyroscopes, and tire pressure sensors. In some example embodiments, automatic load detection system 500 communications with the CPU and receives information from one or more sensors in the vehicle via the CPU. In some example implementations, automatic load detection system 500 includes a user interface 520 based on which automatic load detection system 500 reports to a user the load, load distribution or information determined based on detected load. A display with user interface 520 may communicate with control box 260 or the vehicle CPU by wireless communication. Optionally, the user may control activity and/or reporting of the system via user interface 520. Optionally, user interface 520 includes security and authentication to prevent manipulation of the data by unauthorized users. A user may be the driver or a person overseeing operation of the vehicle, e.g. a fleet manager.

Reference is now made to FIG. 6 showing a simplified flow chart of an example method to detect load in a vehicle in accordance with some embodiments. According to example embodiments, an automatic load detection system samples outputs from one or more of its distance sensors usually when the vehicle is static (block 610). Pressure readings in the vehicles tire may concurrently be retrieved from the CPU of the vehicle or from dedicated pressure sensors. The distance and the tire pressure detected are compared with stored values, e.g. one or more look up tables or reference values based on which load may be determined (block 630). Tire wear may be compensated based on sensed mileage. Load distribution may be determined based on interpolation of output from a plurality of distance sensors positioned at different locations in the vehicle. The load (or load distribution, center of mass) may then be reported (block 640). Reporting may be a report on a user interface that may be viewed by a driver or a fleet manager. Reporting may also be to an application or the CPU of the vehicle.

Reference is now made to FIG. 7 showing a simplified flow chart of an example method to monitor changes in load during transportation in accordance with some embodiments. An automatic load detection system may receive input from sensors included in a vehicle to detect when a vehicle is static (block 710). Based on detection that the vehicle is static, load detection and optionally load distribution detection may be activated. A time that the load was detected and a location of the vehicle at that time may be recorded in association with the detected load (or load distribution) (block 720). A previous load calculation may be retrieved from memory included in the system or in the CPU of the vehicle (block 730). The previous load calculation may also be associated with a time and a location. Based on the time and location or based on input retrieved from sensors included in the vehicle, fuel consumption between the two detections of load may be estimated (block 740). A change in load may be determined based on the two load detections and based on an estimated change in load due to fuel consumption (block 750). The change in load may be reported and/or stored for later reporting (block 760). The report may track loading and unloading of goods from a vehicle and may associate the loading and unloading with recorded locations and times. In some example embodiments, an unexpected change in load may indicate that goods have been stolen. In some example embodiments, a processing unit of the system compares stored delivery instructions or a stored packing list with a current load in the vehicle and detected changes in load at detected locations and times. Based on this information a fleet manager may verify that goods have been delivered at the correct locations.

Reference is now made to FIG. 8 showing a simplified flow chart of an example method to alert a driver that a child (or other object) was forgotten in the vehicle in accordance with some embodiments. According to some example embodiments an automatic load detection system is configured to warn a driver or a surrounding environment that a child was left in the car after the driver locked the doors or after the driver released the seatbelt in the driver's seat. In some example embodiments, the system detects passengers entering a vehicle based on input received from the vehicles CPU or based on a sharp change in load (block 810). Input from the vehicle's CPU may include indication of opening and then closing of a vehicle passenger door and/or locking of seatbelts. Based on an indication that passengers have entered the vehicle, the automatic load detection system may detect the number of passengers, their location in the vehicle and optionally weight of each passenger based on detected distribution of the load (block 820), e.g. the system may check center of mass and the number of passenger and their location. The number of passengers and their location may be verified based on sensors in the vehicle indicating that a seatbelt has been locked (block 825). The system may monitor the load and receive input from the vehicle's CPU to determine when a driver leaves the vehicle and locks the door (block 830). A change in load may be detected based on the distance sensors (block 840). Seatbelt positions (locked or unlocked) may be sensed to determine if a passenger is left locked with a seatbelt in the vehicle (block 845). Fuel consumption may be estimated based on information received from the vehicles CPU (block 850). Based on the estimated fuel consumption and the change in load, the system may detect a change in load due to passengers exiting the vehicle and apply that information to determine if a passenger is still in the vehicle. Alternatively, the number of passengers and their position is detected when a driver releases the seatbelt in the driver seat and the number of passengers and their position is again detected after the driver locks the vehicle. The data is compared to determine if a passenger was left in the car. In such a case, changes in load due to fuel consumption may not be relevant. If the system detects that a passenger was left in the vehicle (block 860) an alert may be provided to the user and/or to the surrounding environment (block 870). For example an alarm may be sounded, headlights may be flashed and/or a driver may receive and alert on a smart phone.

Certain features of the examples described herein, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the examples described herein, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the disclosure. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.