The present invention is related to a method for identification of tire health sensor assembly (also known as TPMS), according to the preamble of claim 1. The present invention is also related to a system for identification of tire health sensor assembly, according to the preamble of claim 8.

Background

Tire pressure management system (TPMS) sensors is a today a substantial component for monitoring tire pressure and possibly temperature in tires of a vehicle, especially heavy vehicles, but also for automobiles. It is now in Europe a requirement in new vehicles that such a system is present. Errors in tire pressure affects the environment, safety and economy negatively.

One of the challenges in TPMS for heavy vehicles is assembly and administration of the sensors in the tires, especially for heavy vehicles that handle different trailers. This can be handled in different ways, but common for the known methods is that they are time consuming or expensive, or both.

A well-known method is auto positioning. To be able to use auto positioning it is required that signal receivers are arranged for each wheel position, including all positions on a trailer. This requires high installations costs on both vehicle and trailer. Another well-known method is administration of sensors by the use of a configuration tool only found in brand specific workshops.

A disadvantage with prior art solutions is that the reader will have to be positioned in close proximity of the sensor in the tire to avoid the possibility for wrong localization of the wheel. In many of the present systems, it is common to arrange the pressure sensor in connection with the valve of the tire, as this will be the only position that is known.

A further problem with the prior art solutions is that heavy vehicles often have dual wheels, wherein the innermost wheel is difficult to access due to the structures of the vehicle or trailer. Heavy vehicles are typically characterized in that they often change trailers several times during a week or several times a day, which require re-configuration of the sensors and control unit/system by means of a configuration tool each time the trailer is exchanged.

Heavy vehicles are further typically characterized by the frequent wheel and tire change, either by the rapid wear or by operational change for the vehicle.

It is accordingly a need for a method and system enabling an easier way to identify tire health sensor assemblies arranged in a tire such that it can be properly connected to a TPMS.

Objects

The main object of the present invention is to provide a method and system for identification of tire health sensor assembly partly or entirely solving the above mentioned lacks or drawbacks of prior art.

It is further an object of the present invention to provide a method and system for identification of tire health sensor assembly enabling easy identification of the tire health sensor assembly in a pressurized tire without the use of special configuration tool or advanced and expensive auto position systems.

An object of the present invention is to provide a method and system for low-cost identification of tire health sensor assembly enabling allocation of the tire health sensor assembly to defined wheel or axle positions.

It is an object of the present invention to provide a method and system for identification of tire health sensor assembly providing automatic or manual identification.

An object of the present invention is to provide a method and system for identification of tire health sensor assembly that enables use of common communication devices, such as tablets, smartphone, computer or similar, for identification.

It is an object of the present invention to provide a method and system for identification of tire health sensor assembly for use both outside workshop environment and in workshop environment.

Further objects of the present invention will appear in the following description, claims and attached drawings. The invention

A method for identification of tire health sensor assembly according to the present invention is disclosed in claim 1. Preferable features of the method are disclosed in the dependent claims.

A system for identification of tire health sensor assembly according to the present invention is disclosed in claim 8. Preferable features of the system are disclosed in the dependent claims.

A system for identification of tire health sensor assembly according to the present invention comprises at least one tire health sensor assembly arranged in a pressurized tire and an external unit/receiver.

The tire health sensor assembly according to the present invention is typically formed by a housing or encapsulation accommodating a sensor module and a unidirectional or duplex communication module. The sensor module is further provided with a control unit with internal or external memory and at least one pressure sensor for measuring tire pressure in a pressurized tire. The tire health sensor assembly can be arranged for measuring current tire pressure and/or for measuring tire pressure variations.

The sensor module can further be provided with sensors for measuring one or more of the following: temperature, vibrations, motion, sound, speed, direction, orientation, moisture, gas, tire pattern depth, etc.

The housing or encapsulation will further be arranged for accommodating power means in the form of at least one battery or capacitor and/or energy harvester. The power means can further include at least one energy harvester capable of providing at least a part of the energy required to operate the tire health sensor assembly. The energy harvester can e.g. be a resonant mechanical device in a material capable of generating electric power when subjected to mechanical influence (e.g. acceleration, rotation, bending, etc.), for example a piezoelectric device or be a device capable of transforming mechanical energy or kinetic energy, for example from mechanical vibration, into electric energy. According to one embodiment of the present invention, the energy harvester is coupled to the battery, such as a Lithium battery, or capacitor.

The sensor(s) of the tire health sensor assembly according to the present invention is preferably sensor(s) consuming low energy such that the tire health sensor assembly will have a lifetime over several years. With an energy harvester in addition to a battery or capacitor the lifetime of such a tire health sensor assembly will be almost unlimited. According to one embodiment of the present invention, the communication module of the tire health sensor assembly is a duplex communication module, which preferably can be integrated with the sensor module, in the form of a short-range wireless duplex communication device (radio, Bluetooth or similar) arranged to communicate with one or more external units. In an alternative embodiment, the duplex communication module is arranged for direct long-range duplex communication from the tire health sensor assembly to web via NB-LTE (Narrow band - Long Term Evolution) or similar technology. In a further embodiment, the duplex communication module is arranged for both short-range and long-range communication.

The duplex communication module, in the case being a radio, preferably uses a proprietary protocol, but can in addition or instead use M-bus or threads protocol or similar, or be arranged for using a number of different protocols.

The duplex communication module accordingly provides bidirectional communication between the tire health sensor assembly and external units/receivers. In this way, the settings of the sensors in the sensor module can be changed, as well as communication protocols, measurement schedules etc.

According to a first embodiment of the present invention it is based on the use of the pressure sensor of the tire health sensor assembly in a new manner, i.e. for identification of the tire health sensor assembly.

According to the first embodiment of the present invention the pressure sensor of the tire health sensor, or a separate pressure sensor arranged in the tire health sensor assembly, is used to detect ultra-short pressure surges inside the pressurized tire generated by a stroke at an external surface of the pressurized tire by hitting the external surface with an object, such as a foot, fist, hammer, wrench or other object, or an object arranged on a surface, such as an elevation, the pressured tire can run over, which provides a deformation of the pressurized tire when the pressurized tire runs over it that induces pressure surges inside the pressurized tire. According to the present invention, the pressure sensor or separate pressure sensor is arranged to detect these ultra-short pressure surges and upon such a detection the tire health sensor assembly is arranged to report its identification code via a wireless link to an external unit/receiver.

According to a second embodiment of the present invention at least one vibration sensor is arranged in the tire health sensor assembly is used to detect mechanical vibration in the tire or a rim for the tire, generated by a stroke at an external surface of the pressurized tire by hitting the external surface with an object, such as a foot, fist, hammer, wrench or other object, or an object arranged on a surface, such as an elevation, the pressured tire can run over, which provides a deformation of the pressurized tire when the pressurized tire runs over it that induces mechanical vibrations inside the pressurized tire or in a rim of the pressurized tire. According to the present invention, the at least one vibration sensor is arranged to detect these mechanical vibrations and upon such a detection the tire health sensor assembly is arranged to report its identification code via a wireless link to an external unit/receiver.

In a third embodiment of the present invention, the tire health sensor assembly is provided with an acoustic sensor, as mentioned above, or a separate acoustic sensor, wherein the acoustic sensor is arranged to detect a specific acoustic signal applied internally or externally of the pressurized tire. The specific acoustic signal will have a predetermined frequency, wavelength and strength, that is adapted the tire in question to ensure that the acoustic signal will penetrate the tire and be able to be detected by the acoustic sensor of the tire health sensor assembly. Upon detection of the specific acoustic signal, the tire health sensor assembly is arranged to report its identification code via a wireless link to an external unit/receiver.

The applied acoustic signal will be provided by an acoustic signal generator, such as a speaker. This can e.g. be a speaker of a smartphone, tablet, computer or similar. Another example of an acoustic signal generator is provided by a valve adapted tool, which upon connection to the valve of the tire is arranged to apply a specific acoustic signal into the pressurized tire via the valve or is arranged to provide a specific acoustic signal by functioning as a whistle by utilizing outgoing air. A further example would be to implement an acoustic signal generator, such as a speaker, in a surface the pressurized tire can run over, wherein a predefined acoustic signal is applied when the pressurized tire runs over the acoustic signal generator.

According to a further embodiment of the present invention the acoustic sensor of the tire health sensor assembly, it is further used to receive low-speed data.

According to a further embodiment of the present invention the tire health sensor assembly is arranged for using both acoustic signal and detection of ultra-short pressure surges in connection with identification of the tire health sensor assembly.

Accordingly, in the present invention the tire health sensor assembly can be arranged to continuously monitoring, which is power consuming. The tire pressure sensor can for this be provided with energy harvesting means such that the tire pressure sensor is continuously supplied with power. In an alternative embodiment of the present invention, the tire health sensor assembly is provided with a bidirectional communication module, enabling the tire health sensor assembly to be remotely activated for registration purpose, i.e. searching for ultra-short pressure surges or mechanical vibrations or predefined acoustic signals within a predefined time. By this, the operation time of the tire health sensor assembly will be affected in a minimal manner.

It is accordingly important that the ultrashort pressure surges are detected with as low energy consumption in a control unit as possible. For a control unit this means that it must use as short time as possible for performing mathematical calculations.

According to one embodiment of the present invention, this is achieved by summarization of absolute delta value for the measured pressure from a sampling.

This can be performed as follows: abs(pressure measurement 1) - abs(pressure measurement 2) = dl abs(pressure measurement 2) - abs(pressure measurement 3) = d2 abs(pressure measurement n-1) - abs(pressure measurement n) = dn sum delta = dl + d2 ... + dn sum delta is compared to a predefined limit value and if the sum delta is higher than the predefined limit value (typically a few millibar) the tire health sensor assembly is arranged to report its identification code via a wireless link to a receiver. In practice, this will be a digital high-pass filter specially designed for reacting to sharp/rapid pressure changes. By this approach slower pressure changes, such as from filling of air, which is slow changes, will not be detected as a registration operation and will not result in that the tire pressure sensor sends its identification code. The ultra- short pressure surges to be included in the above-mentioned summarization can e.g. be limited by a time frame, such as up to 20 ms, from first to last summarized ultra-short pressure surge, and wherein each pressure measurement is performed at a sampling rate of e.g., but not limited to, 300Hz and comparing e.g., but not limited to, the last 8 values.

As the entire processing is using integer values with addition and subtraction it has extremely short processing time with low power consumption as a result.

The pressure sensor might also be constructed to detect sudden changes by piezo-electric or capacitive technology and by hardware topology be tuned for detecting the short pressure surges. The external unit/receiver can e.g. be a smartphone, tablet, computer or similar provided with a wireless communication device and means or software, such as an application (App) or computer executable software, for allocating correct tire position when the identification code is received from the tire health sensor assembly. The external unit/receiver can further be arranged for storing of the identification code and tire position in a cloud on the web.

The tire health sensor assembly can further be arranged for communication with the external unit/receiver via a data acquisition unit arranged in the trailer or vehicle directly or via in addition via the web (cloud), or communication via the web (cloud).

The cloud can further be arranged to keep track of which trailer is arranged to which vehicle and one can manually or automatic connect relevant vehicle and trailer.

The method and system according to the present invention accordingly eliminates the need for advanced configuration tools and replaces this with an external stroke or external or interior acoustic signal that activates the tire health sensor assembly in the pressurized tire to wirelessly transmit its identification code to an external unit/receiver for easy allocation of the tire health sensor assembly to correct tire position.

The present invention further removes the need for complex and integrated systems for this in the vehicle and trailers.

Further preferable features and advantageous details of the present invention will appear in the following example description, claims and attached drawings.

Example

The present invention will below be described in further detail with references to the attached drawings, where:

Fig. 1 is a principle drawing of a tire health sensor assembly arranged in a pressurized tire, Fig. 2 is a block diagram of a sensor module according to the present invention, and

Fig. 3a-b are principle drawings of the use of an object to apply ultra-short pressure surges in a pressurized tire or mechanical vibrations in the pressurized tire or rim of the pressurized tire, Fig. 4a-b are principle drawings of the use of an acoustic signal generator to apply a specific acoustic signal exterior or interior of a pressurized tire, and

Fig. 5 is a principle drawing of communication between a tire health sensor assembly and an external unit/receiver.

Reference is now made to Figures 1 and 2 which show a principle drawing of a tire health sensor assembly 10 arranged in a pressurized tire 100 of a vehicle and a block diagram of a sensor module 30 according to the present invention, respectively. The term vehicle is in this application related to vehicles on wheels, such as trailers, trucks, tractors, loading shovel, cars, caravans, aircrafts, etc.

A tire health sensor assembly 10 according to the present invention is based on a housing or enclosure 20, as well known in prior art.

The sensor module 30 of the tire health sensor assembly 10 according to a first embodiment comprise a control unit 31 with internal and/or external memory, and at least one pressure sensor 32 for measuring tire pressure and tire pressure variations in a pressurized tire 100 and power supply means 33 and/or energy harvester 37.

The tire health sensor assembly 10 is further provided with a unidirectional or duplex wireless communication module 34, which can be integrated with the sensor module 30 or be a separate module. The further description will be related to a duplex wireless communication module 34.

The tire health sensor assembly 10 in a further embodiment includes two or more pressure sensors 32 measuring tire pressure and tire pressure variations in a tire 100 for redundancy or average measuring, but will also be arranged for detection of ultra-short pressure surges according to one embodiment of the present invention for identification purpose, which will be described in further detail below. The encapsulation or housing 20 is for enabling measuring of tire pressure preferably provided with an opening 21, allowing air/gas in the pressurized tire 100 to enter the encapsulation or housing 20 and enable pressure measurement by the at least one pressure sensor 32.

According to a further embodiment of the tire health sensor assembly 10 according to the present invention it further preferably is provided with at least one temperature sensor 35 for measuring temperature in a pressurized tire 100. According to a further embodiment of the tire health sensor assembly 10 according to the present invention it further preferably is provided with at least one motion sensor 36, e.g. in the form of at least one accelerometer, gyroscope or similar, for measuring wheel motions, as well as direction and orientation of the tire health sensor assembly 10.

The wireless duplex communication module 34 is according to a first embodiment a short range wireless duplex communication device, such as RFID communication with NFC technology or similar, enabling duplex communication with external units/receivers 200, such as a smartphone, pad, computer or similar, as well as external central units 210 arranged in each sub vehicle (e.g. separately in trailer and vehicle) or a common external (central) unit 210 for this arranged in the main vehicle, wherein the external units/receivers 200, 210 are provided with corresponding communication modules.

The duplex communication module 34 according to a second embodiment is in addition arranged for direct duplex communication from the tire health sensor assembly 10 to web (cloud) 300 via NB long range radio, such as NB-LTE, LoRa, NB-IOT or similar technology.

According to a further embodiment, the wireless duplex communication module 34 instead or in addition is arranged for Bluetooth communication for enabling communication with external units/receivers 200, such as a smartphone, pad, computer or similar.

In a further embodiment the duplex communication module 34 is arranged for both short range and long range communication.

The power means 33 is preferably one or more batteries (Lithium) or capacitors. In an alternative embodiment the batteries or capacitors are chargeable and arranged to at least one energy harvester 37 capable of providing at least a part of the energy required to operate the tire health sensor assembly 10. In a further alternative embodiment there is only an energy harvester 37 is used. The energy harvester 37 can e.g. be a resonant mechanical device in a material capable of generating electric power when subjected to mechanical influence (e.g. acceleration, rotation, bending, etc.), for example a piezoelectric device or be a device capable of transforming mechanical energy or kinetic energy, for example from mechanical vibration, into electric energy.

According to a further embodiment, the tire health sensor assembly 10 includes several energy harvesters 37 designed to harvest energy from different sources, such as one for vibration, one for acceleration, one for temperature, etc. According to an alternative embodiment of the sensor module 30 according to the present invention it is provided with a vibration sensor for identification purpose, as will be discussed in further detail below.

According to an alternative embodiment of the sensor module 30 according to the present invention it is provided with a sound sensor 38 for identification purpose, as will be discussed in further detail below.

According to a further embodiment of the sensor module 30 of the tire health sensor assembly 10 according to the present invention, the sensor module 30 is further preferably provided with one or more sensors for measuring one or more of the following: vibration, sound, speed, direction, orientation, moisture, gas, tire pattern depth, etc.

A vibration sensor (of known type) and/or sound sensor (of known type) and/or accelerometers can be used to detect abnormal vibrations in the wheel, as well as bearings, brakes, shafts etc. Accordingly, accelerometers and/or vibration sensors can be used both for detection of abnormal vibrations and for harvesting energy.

Accelerometers can further be used for detecting orientation and/or direction of the tire health sensor assembly 10 in the pressurized tire 100, as well as speed/velocity of the pressurized tire 100.

The sensor module 30 can further be provided with at least one capacitive and/or inductive sensor for measuring tire pattern depth, which capacitive and/or inductive sensor(s) also can be used as energy harvesters.

According to a further embodiment of the tire health sensor assembly 10 according to the present invention the sensor module 30 can further include at least one moisture sensor which can detect intrusion of water/condense into the tire health sensor assembly 10/tire 100.

According to a further embodiment of the tire health sensor assembly 10 according to the present invention the sensor module 30 includes at least one gas sensor which can detect the content/amount of gases in a tire 100. Usually tires 100 are filled with compressed air that is a combination of roughly 78 % nitrogen (N2), 21 % oxygen (O2) and 1 % miscellaneous gases. In certain areas of use, such as racing tires, aircraft tires (commercial and military) and heavy-duty equipment tires (earthmovers and mining equipment) it is used a higher content of nitrogen and even pure nitrogen is used in some application. By that the sensor module 30 includes a gas sensor one will be able to detect the amount of different gases in the pressurized tire 100, and thus the content can be changed by supplying the relevant gas.

The control unit 31 will further be provided with means and/or software for controlling the sensors of the sensor module 30, as well as the communication module 34, such as by adjusting measurement frequency, transmission frequency and other relevant parameters of the sensors and communication module 34.

The control unit 31 can further be provided with means and/or software for performing tire pressure variation measurement.

The key features of the present invention will now be described, which enables the use of the above described tire health sensor assembly 10 in a novel way to provide identification and allocation of a tire on a vehicle.

According to one embodiment of the present invention the pressure sensor 32 or separate pressure sensor 32 is used to detect ultra-short pressure surges inside the pressurized tire generated by a stroke at an external surface of the pressurized tire 100, such as by kick, stroke with a fist, hammer, wrench or other object 400, as shown in Figure 3a and exemplified by an adjustable wrench, or at least one object 400 on a surface 410, such as an elevation 400, as shown in Figure 3b, the pressurized tire can run over, which provides a deformation of the tire when the pressurized tire 100 runs over it that induces a pressure surge inside the pressurized tire 100. For a vehicle or trailer several devices 400 arranged on a surface 410 can be used, arranged in a pattern, such that each vehicle or trailer tire 100 runs over devices at different times. This will require that the pressure sensor 32 is capable of detecting rapid (<5ms) and ultra-short pressure surges (<2mBar) in a pressurized tire 100 (e.g. 10 bar), wherein the signal-to-noise ratio typically will be 1:5000.

The pressure sensor 32 is arranged to detect these ultra-short pressure surges, and the tire health sensor assembly 10 is upon such a detection arranged to activate the control unit 31, which activates the wireless communication module 34, and reports the identification code of the tire health sensor assembly 10 to the external unit/receiver 200, 210 via a wireless link 220, as shown in Figure 5.

According to a further embodiment the tire health sensor 30 is provided with at least one vibration sensor used to detect mechanical vibrations in the pressurized tire 100 or a rim for the pressurized tire 100, generated by a stroke at an external surface of the pressurized tire 100 by hitting the external surface with an object 400, such as a foot, fist, hammer, wrench or other object, or by running over the elevations 400, as described above. The embodiment works as the embodiment with pressure sensor 32, but instead of detecting ultra-short pressure surges the vibration sensor detects mechanical vibrations in the pressurized tire 100 or rim for the pressurized tire 100 to activate the control unit 31, which activates the wireless communication module 34, and reports the identification code of the tire health sensor assembly 10 to the external unit/receiver 200, 210 via a wireless link 220, as shown in Figure 5.

According to a further embodiment of the present invention the acoustic sensor 38 or a separate acoustic sensor 38 is used to detect a specific acoustic signal applied internally or externally of the pressurized tire 100. Upon detection of the specific acoustic signal, the tire health sensor assembly 10 is arranged to activate the control unit 31, which activates the wireless communication module 34, and reports the identification code of the tire health sensor assembly 10 to the external unit/receiver 200, 210 via a wireless link 220.

The specific acoustic signal will be provided by an acoustic signal generator 500, such as a speaker. E.g. a speaker 500 of a smartphone 200, tablet, computer or similar can be used as an acoustic signal generator 500, as shown in Figure 4a. Another example is by integration of an acoustic signal generator 500 in a valve adapted tool 510, as shown in Figure 4b, which upon connection to a valve 110 of the pressurized tire 100 is arranged to send an acoustic signal into the pressurized tire 100 via the valve 110 or is arranged to provide a specific acoustic signal by functioning as a whistle by utilizing outgoing air. A further example would be to implement at least one acoustic signal generator 500 in a surface 410 the pressurized tire 100 can run over, as shown in Figure 4c, wherein a predefined acoustic signal is applied when the pressurized tire 100 runs over the acoustic signal generator 500. For a vehicle or trailer several acoustic signal generators 500 can be arranged in a pattern in the surface 410, such that each vehicle or trailer tire runs over acoustic signal generators 500 at different times.

In a further embodiment, not shown the acoustic signal generator 500 is arranged in an object 400 on a surface 410, such that both acoustic signal and pressure surges can be used in connection with the identification process.

Accordingly, when an identification process is to be performed an external stroke is applied to a desired pressured tire 100 or an external or interior specific acoustic signal is applied to a desired pressurized tire 100, as described above. The tire health sensor assembly 10 next responds to this by transmitting its identification code, as described above via the wireless communication module 34. The wireless communication module 34 can communicate, as shown in Figure 5: directly with a smartphone 200, tablet or computer of an operator, directly with a data acquisition unit 210 in the vehicle or trailer, which again can communicate with the smartphone 200, tablet or computer of an operator directly or via web 300 (cloud), communicate directly with web 300 (cloud) which again can communicate with the smartphone 200, tablet or computer of an operator directly or via the data acquisition unit 210 in the vehicle or trailer.

The smartphone 200, tablet or computer of an operator and/or data acquisition unit 210 can in any case be arranged for communication with the web 300 (cloud).

When the smartphone 200, tablet or computer of an operator in any way of the above described communication paths receives the identification code of the tire health sensor assembly 10 in question, the operator can allocate the tire health sensor assembly 10 to the correct tire position by using means and/or software (application) on the smartphone200, tablet or computer and possibly store this in the web 300 (cloud).

The method according to the present invention can further comprise a in initial step of arranging the tire health sensor assembly 10 in an identification mode before the activation process is initiated, wherein the pressure sensor 32 or vibration sensor or acoustic sensor 38 will be set to search for ultra-short pressure surges or specific mechanical vibrations or specific acoustic signals, respectively, as described above. For this the wireless communication module 34 of the tire health sensor assembly 10 will have to be arranged for duplex communication. An operator can then use an external unit 200, 210 for setting the tire health sensor assembly 10 in identification mode, whereupon an external stroke or specific acoustic signal is applied as described above. This will be favorable for saving power of the tire health sensor assembly 10 and avoiding the tire health sensor assembly 10 for discharging of power.

Modifications The pressure sensor of the tire health sensor assembly can be arranged for ultra-low power consumption in an active measurement state and be used for ultra-rapid detection of a puncture by that it is arranged for detection of ultra-short pressure surges or as parts of a stability control system of a vehicle. According to a further embodiment of the present invention the pressure sensor for detecting ultra- short pressure surges in an automatic mode by utilizing irregularities on a road, known as washboard, for identification of tire health sensor assemblies 10.

Strokes or deformations of different pressurized tires 100 will result in signatures of pressure waves (ultra-short pressure surges) which according to a further embodiment of the present invention can be compared to signatures stored in a database for identifying the type of pressurized tire 100 the tire health sensor assembly 10 is arranged in.