Automotive vehicle calculator for wheel theft detection

Abstract

The invention relates to a method for alerting theft of a wheel (10) of a motor vehicle (1), said vehicle (1) comprising a plurality of wheels (10) and a computer (30), at least one of the wheels (10) comprising a sensor (20), said method being characterized in that it comprises, for the at least one wheel (10), the steps of measuring at least one value of the internal pressure of the tire of the wheel (10), detecting the lifting of the vehicle (1) if the absolute value of the difference between the at least one measured internal pressure value and a predetermined reference internal pressure value is greater than a predetermined pressure difference threshold, when the lifting of the vehicle (1) is detected, detecting the distance of the wheel (10), when the distance of the wheel (10) is detected, alerting the theft of the wheel (10). Figure for abstract: Figure 1

Description

Title of the invention: Motor vehicle computer for detecting wheel theft Technical field

[0001] The invention relates to the field of sensors for motor vehicles and more specifically a wheel sensor for detecting the theft of the wheels of a motor vehicle. State of the art

[0002] Stealing a wheel from a motor vehicle involves several steps. First, the vehicle must be raised, for example using a jack. Then the wheel clamping bolts must be removed, followed by the wheel itself.

[0003] Nowadays, in order to prevent wheel theft on a vehicle, it is known to mount a wheel anti-theft system on the vehicle.

[0004] In a first solution, the wheel anti-theft system comprises anti-theft nuts mounted on each wheel of the vehicle. A suitable unlocking key is used to mount or dismount said anti-theft nuts.

[0005] In a second solution, the anti-theft system is a vehicle lifting detection system. When the vehicle is lifted, the anti-theft system activates an alarm, audible to anyone near the vehicle and intended to scare off the thief.

[0006] However, both of these solutions have drawbacks.

[0007] First of all, the key to unlock the anti-theft bolts is often kept by the owner in the vehicle itself. Thus, it is easy for the thief to break into the vehicle to retrieve the unlocking key. Furthermore, the thief may also have a copy of the unlocking key in his possession.

[0008] The lifting system, for its part, is an additional system which can prove to be particularly expensive.

[0009] There is therefore a need for a solution that can at least partially remedy these drawbacks. Statement of the invention

[0010] To this end, the invention firstly relates to a method for alerting the theft of a wheel of a motor vehicle, said vehicle comprising a plurality of wheels and a computer, at least one of the wheels comprising a sensor, said method being characterized in that it comprises, for the at least one wheel, the steps of: - measurement of at least one value of the internal pressure of the wheel tire, - detection of vehicle lifting when the absolute value of the difference between the at less than one measured internal pressure value and one predetermined reference internal pressure value is greater than a predetermined pressure difference threshold, - when vehicle lifting is detected, wheel distance detection, - when wheel distance is detected, wheel theft alert.

[0011] The method makes it possible to detect the theft of a wheel of a vehicle and to alert the owner or user of said vehicle of the theft of the wheel if necessary. The method thus implemented does not require the addition of an expensive additional device or the use of an unlocking tool. Indeed, the method is implemented by a computer and at least one sensor, already present in the vehicle.

[0012] Preferably, the step of detecting the distance of the wheel comprises the steps of: - in a so-called “lifting” mode, periodic emission by the sensor of a lifting detection signal to the computer as long as the lifting of the vehicle is detected, - reception by the computer of said emitted lifting detection signal, - measurement of the power of the received lifting detection signal, - detection of wheel distance by the calculator if at least one measured power value is lower than a predetermined power threshold.

[0013] Thus, the method makes it possible to simply and quickly detect the distance of the wheel from the vehicle since a measurement of the power of a signal is simple and quick to implement.

[0014] According to another embodiment, the distance of the wheel is detected if the absolute value of the difference between the measured power value and a predetermined reference power value is greater than a predetermined power variation threshold.

[0015] Advantageously, the at least one lifting detection signal emitted is a radiofrequency type signal.

[0016] A radio frequency type signal is simple to use.

[0017] According to another embodiment, the step of detecting the distance of the wheel comprises the steps of: - emission, by the sensor, of at least one lifting detection signal to the computer, - reception by the computer of said at least one emitted lifting detection signal, - periodic emission, by the computer, of a response signal to the sensor following receipt of said at least one lifting detection signal, - reception, by the sensor, of each response signal sent by the computer, - measurement, by the sensor, of the power of each response signal received, - detection of wheel distance by the sensor if at least one measured power value is lower than a second predetermined power threshold.

[0018] Thus, the method makes it possible to simply and quickly detect the distance of the wheel from the vehicle since the measurement of the power of a signal, by the sensor, is simple and quick to implement.

[0019] According to another embodiment, the distance from the wheel is detected if the absolute value of the difference between at least one measured power value and a second predetermined reference power value is greater than a second predetermined power variation threshold.

[0020] In another embodiment, the step of detecting the distance of the wheel comprises the following steps: - emission of a lifting detection signal by the sensor to the computer, - reception by the computer of the emitted lifting signal, - measurement, by the sensor, of at least two acceleration values ​​along the axis of rotation of the wheel, - sending, by the sensor, of each measured acceleration value to the calculator, - detection of the wheel distance by the calculator if the absolute value of the variation in the measured acceleration is greater than a predetermined acceleration variation threshold.

[0021] Thus, the method makes it possible to simply and quickly detect the distance of the wheel from the vehicle since the measurement of the acceleration, by the computer, is simple and quick to implement.

[0022] The distance of the wheel can also be detected by the computer if the absolute value of the difference between at least one received measured acceleration value and a predetermined reference acceleration value is greater than a predetermined acceleration variation threshold.

[0023] In another embodiment, the step of detecting the distance of the wheel comprises the following steps: - emission of a lifting detection signal by the sensor to the computer, - reception by the computer of the emitted lifting signal, - measurement, by the sensor, of at least two acceleration values ​​along the axis of rotation of the wheel, - detection of the wheel distance by the sensor if the absolute value of the variation in the measured acceleration is greater than a predetermined acceleration variation threshold.

[0024] Thus, the method allows simply and quickly to detect the distance of the wheel relative to the vehicle since the measurement of acceleration, by the sensor, is simple and quick to implement.

[0025] The wheel movement can also be detected if the absolute value of the difference between at least one measured acceleration value and a predetermined reference acceleration value is greater than a predetermined acceleration variation threshold.

[0026] The wheel drift can also be detected if the absolute value of at least one measured acceleration value is greater than a predetermined acceleration threshold.

[0027] Advantageously, during the step of detecting the distance of the wheel, the computer is configured to send an alert signal to the user of the vehicle in the event of theft of the wheel. For example, the alert signal is a text message (a message) sent to the smartphone of the user of the vehicle.

[0028] The method thus makes it possible to warn the user of the vehicle, who can in particular attempt to prevent the thief from completely stealing a wheel of the vehicle, or who can alert the police about this.

[0029] According to another embodiment, during the step of detecting the distance of the wheel, the sensor is configured to alert of the theft of the wheel, for example by sending an alert signal to the user of the vehicle.

[0030] The invention also relates to a computer program product characterized in that it comprises a set of program code instructions which, when executed by one or more processors, configure the processor(s) to implement a method as described above.

[0031] The invention also relates to a computer for a motor vehicle, said vehicle comprising a plurality of wheels, at least one of the wheels comprising a sensor, the computer being configured to: - receive a lifting detection signal emitted periodically by the sensor, - measure the power of the received lifting detection signal, - detect wheel distance if at least one measured power value is lower than a predetermined power threshold, - alert of wheel theft when wheel distance has been detected.

[0032] According to another embodiment, the calculator is configured to detect the distance of the wheel if the absolute value of the difference between the measured power value and a predetermined reference power value is greater than a predetermined power variation threshold.

[0033] According to another embodiment, the calculator is configured to: - receive a lifting detection signal emitted periodically by the sensor, - receive at least two acceleration values ​​measured by the sensor, - detect the wheel movement if the absolute value of the measured acceleration variation is greater than a predetermined acceleration variation threshold, - alert of wheel theft when wheel distance has been detected.

[0034] The invention also relates to a sensor for a motor vehicle, said vehicle comprising a plurality of wheels and a computer, said sensor being intended to be mounted in a wheel of said vehicle, said sensor being configured to: - measure at least one value of the internal pressure of the wheel tire, - detecting the lifting of the vehicle if the absolute value of the difference between the at least one measured internal pressure value and a predetermined reference internal pressure value is greater than a predetermined pressure difference threshold, - send a lifting detection signal to the computer, - according to a lifting mode, periodically measure the acceleration along the axis of rotation of the wheel, - detect the wheel moving away when the absolute value of the measured acceleration variation is greater than a predetermined acceleration variation threshold, - alert of wheel theft when wheel distance has been detected.

[0035] According to another embodiment, the sensor is configured to: - transmit at least one lifting detection signal to the computer, - periodically receive a response signal emitted by the computer, - measure the power of each response signal received, - detect the wheel moving away if at least one measured power value is lower than a second predetermined power threshold, - alert of wheel theft when wheel distance has been detected.

[0036] Preferably, the sensor is configured to alert of theft by sending a signal detecting the distance of the wheel to the computer.

[0037] More preferably, the sensor is configured to alert of the theft by sending an alert signal to the user of the vehicle.

[0038] The invention also relates to a motor vehicle, said vehicle comprising a plurality of wheels and a computer, at least one of the wheels comprising a sensor, the computer and the at least one sensor being configured to implement the method as described previously. Description of the figures

[0039] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This description is purely illustrative and should be read in conjunction with the appended drawings in which: [Fig.l]: [Fig.l] schematically illustrates an embodiment of the vehicle according to the invention, [Fig.2]: [Fig.2] schematically illustrates an embodiment of the method according to the invention. Detailed description of at least one embodiment

[0040] With reference to [Fig.l], an embodiment of the vehicle 1 according to the invention will be presented.

[0041] The vehicle 1 comprises a plurality of wheels 10 and at least one computer 30 comprising a reception module, and in particular a radiofrequency reception module.

[0042] Each wheel 10 of the vehicle 1 comprises a tire.

[0043] At least one of the wheels 10 of the vehicle 1 comprises a sensor 20. Preferably each wheel 10 of the vehicle 1 comprises a sensor 20.

[0044] The sensor 20 is in particular mounted on the inflation valve of the tire of the wheel 10. For example, the sensor 20 is a temperature and pressure sensor commonly called “TPMS”, for “Tyre Pressure Monitoring System”, known to those skilled in the art, and will not be described in more detail here.

[0045] The sensor 20 is in particular connected to the computer 30, via a wireless communication link. More precisely, a first wireless communication link, in particular a radiofrequency RF communication link, allows the sensor 20 to send signals to the computer 30. Conversely, a second communication link, in particular a low frequency LF communication link, for “Low Frequency” in English, allows the computer 30 to send signals to the sensor 20.

[0046] The sensor 20 is notably configured to detect a stationary position of the vehicle. In other words, the sensor 20 detects that the vehicle 1 is indeed parked, and that the vehicle is not simply temporarily stopped. For this, the sensor 20 detects when the vehicle 1 stops, then when the vehicle 1 has been stopped for a duration greater than a predefined transition duration dt, for example equal to 15 minutes.

[0047] In order to verify that the vehicle 1 is in a stationary position, the sensor 20 can also be configured to measure the temperature in the tire, in other words the temperature of the gases occupying the interior volume of the wheel 10. If the value of the measured temperature is lower than a predefined resting temperature, then the sensor 20 is configured to confirm that the vehicle 1 is in a stationary position.

[0048] The resting temperature defines the temperature reached by each tire when the vehicle 1 has been stopped for a period longer than the predefined transition time dt, in other words when the vehicle 1 is in a stationary position. For example, the resting temperature is 40°C.

[0049] The sensor 20 comprises a memory area in which the value of the resting temperature is recorded.

[0050] When the sensor 20 has detected that the vehicle 1 is in a stationary position, said sensor 20 is configured to measure the value of the initial reference internal pressure Pie[lllll in the tire of the wheel 10.

[0051] Similarly, the sensor 20 is configured to measure the value of the initial reference temperature Tref init in the tire of the wheel 10.

[0052] The measured initial reference internal pressure value Pref init and the measured initial reference temperature value Tref init are also recorded in the memory area of ​​the sensor 20.

[0053] The sensor 20 is also configured to transmit a presence signal sp to the computer 30, via the first wireless communication link, in particular when the sensor 20 has detected that the vehicle 1 was in a stationary position. The presence signal sp comprises an identifier, allowing the computer 30 to identify which sensor 20, and therefore which wheel 10, has transmitted the presence signal sp. The presence signal sp also comprises the initial reference temperature Tref_init measured, the initial reference internal pressure Pref_initmeasured and information indicating to the computer 30 that the sensor 20 has detected that the vehicle 1 is in a stationary position.

[0054] In addition, the sensor 20 is configured to check that the tire of the wheel 10, to which the sensor 20 belongs, is sufficiently inflated. For this, the sensor 20 is configured to measure the internal pressure Pi0 of the tire of the wheel 10, that is to say the pressure of the gases occupying the internal volume of the wheel 10. Then, if the value of the measured internal pressure Pi0 is greater than a predefined minimum inflation threshold, then the tire is correctly inflated. The minimum inflation threshold is in particular equal to 300 kPa. The value of the minimum inflation threshold is also recorded in the memory area of ​​the sensor 20.

[0055] In addition, the sensor 20 is also configured to check the stability of the temperature in the tire of the wheel 10, to which the sensor 20 belongs. For this, the sensor 20 again measures the value of the temperature in the tire. The sensor 20 is configured to determine that the temperature is stable when the absolute value of the difference between the temperature measured in the tire and the initial reference temperature Tref init determined for said tire, is less than a predefined temperature threshold. The temperature threshold is for example equal to 3 °C and the value of said temperature threshold is recorded in the memory area of ​​the sensor 20.

[0056] The sensor 20 can also be configured to determine a reference temperature value Tref, by measuring the temperature in the tire, by example every 30 or 60 seconds. The reference temperature Tref corresponds to an update of the value of the initial reference temperature Tref_init.

[0057] In addition, when a reference temperature value Tref has been measured, the sensor 20 is configured to re-check the stability of the temperature, by measuring the temperature value in the tire again. The sensor 20 is configured to determine that the temperature is stable when the absolute value of the difference between the temperature measured in the tire and the reference temperature Tref determined for said tire, is lower than the temperature threshold.

[0058] The sensor 20 is also configured to operate in a so-called “monitoring” mode of the tire of the wheel 10 to which the sensor 20 belongs. In the monitoring mode, the sensor 20 is configured to detect the lifting of the wheel 10, to which the sensor 20 belongs, relative to the ground. Lifting therefore also designates the lifting, partial or complete, of the vehicle 1 relative to the ground.

[0059] For this, in the monitoring mode, the sensor 20 is configured to periodically measure, for example every 4 seconds, the internal pressure Pi0 of the tire of the wheel 10, in order to detect the lifting of the vehicle 1. More precisely, the sensor 20 is configured to detect the lifting of the vehicle 1 if the absolute value of the difference between the measured internal pressure value Pi0 and the value of the initial reference internal pressure Pref_initest is greater than a predetermined pressure difference threshold. The predetermined pressure difference threshold is in particular equal to 1.5 kPa and its value is recorded in the memory area of ​​the sensor 20.

[0060] The sensor 20 is in particular configured to periodically measure the reference internal pressure value Pref, for example by measuring the internal pressure of the tire every 30 seconds or every 60 seconds. The reference internal pressure value Pref corresponds in particular to the update of the initial reference internal pressure value Prefjnif

[0061] Similarly, when the sensor 20 has measured a new value of the reference internal pressure Pref, the sensor 20 is configured to detect the lifting of the vehicle 1 by periodically measuring again, in particular every 4 seconds, the value of the internal pressure Pi0 in the tire. The lifting of the vehicle 1 is detected by the sensor 20 if the absolute value of the difference between the measured internal pressure value Pi0 and the determined reference internal pressure value Pref is greater than the predetermined pressure difference threshold.

[0062] According to another example, the sensor 20 is configured to detect the lifting of the vehicle 1 if the measured internal pressure Pi0 decreases, in other words, if the measured internal pressure variation Pi0 is negative.

[0063] After detecting the lifting of the vehicle 1, the sensor 20 is configured to operate in a so-called “lifting” mode.

[0064] According to a first embodiment of the sensor 20, when the sensor 20 operates in the lifting mode, the sensor 20 is configured to periodically transmit a lifting detection signal to the computer 30, via the first communication link, as long as the lifting of the vehicle 1 is detected. For example, the sensor 20 transmits a lifting detection signal every 4 seconds.

[0065] The lifting detection signal notably comprises an identifier allowing the computer 30 to identify which sensor 20 sent the lifting detection signal, lifting information indicating that lifting is detected and at least one wake-up stimulus, making it possible to ensure that the reception module of the computer 30 is in a wake-up state to receive the identifier and the lifting information.

[0066] According to a second embodiment of the sensor 20, the sensor 20, operating in lifting mode, is configured to transmit a lifting detection signal, as described in the first embodiment, to the computer 30 via the first communication link. The sensor 20 is then configured to periodically receive a response signal from the computer 30 via the second communication link. The sensor 20 is then configured to measure the power of each response signal received. In particular, the power corresponds to the RSSI, for “Received Signal Strength Indication” in English.

[0067] Finally, the sensor 20 is configured to detect the distance of the wheel 10 comprising the sensor 20, relative to the vehicle 1, if the absolute value of the difference between at least one measured power value and a second predetermined reference power value PRSsi_ref2 is greater than a second predetermined power variation threshold.

[0068] The distance of the wheel 10, relative to the vehicle 1, designates in particular the withdrawal of the wheel 10 from the vehicle 1 and a movement of said wheel 10 relative to the vehicle 1.

[0069] The second reference power value PRssi_ref2 may be predetermined by the manufacturer. In another embodiment, the sensor 20 is configured to determine the second reference power value PRSsi_ref2, in particular by measuring the power of the first response signal received by the sensor 20. In the two cases described above, the reference power value PRSsi_ref2 is in particular recorded in the memory area of ​​the sensor 20.

[0070] The second predetermined power variation threshold is for example equal to 5 dBm. The value of the second power variation threshold is notably recorded in the memory area of ​​the sensor 20.

[0071] According to another example, the sensor 20 is configured to detect the distance of the wheel 10 if the value of the measured power is less than a second predetermined power threshold. In the present case, the second predetermined power threshold determined is in particular equal to - 34 dBm. The value of the second power threshold is in particular recorded in the memory zone of the sensor 20.

[0072] In the event of detection of the distance of the wheel 10, the sensor 20 is configured to send at least one distance detection signal to the computer 30 via the first communication link, signifying that a wheel 10 is moving away from the vehicle, and therefore that there is theft of said wheel 10.

[0073] According to another example, in the event of detection of the distance of the wheel 10, the sensor 20 is configured to send a wheel 10 theft alert to the driver or user of the vehicle 1 whose wheel 10 has been stolen.

[0074] According to a third embodiment of the sensor 20, the sensor 20, operating according to the lifting mode, sends a lifting detection signal, as described previously in the first embodiment of the sensor 20, to the computer 30 via the first communication link, to indicate to the computer 30 that lifting is detected.

[0075] In addition, the sensor 20 is configured to periodically measure the acceleration of the wheel 10, to which the sensor 20 belongs, along the axis of rotation of the wheel 10.

[0076] In addition, the sensor 20 is configured to send each measured acceleration value to the computer 30 via the first communication link.

[0077] In addition, the sensor 20 is configured to determine the reference acceleration value and to send the determined reference acceleration value to the computer 30, for example by integrating the reference acceleration value into the presence signal sp.

[0078] According to a fourth embodiment of the sensor 20, the sensor 20, operating according to the lifting mode, sends a lifting detection signal, as described previously in the first embodiment of the sensor 20, to the computer 30 via the first communication link, to indicate to the computer 30 that lifting is detected.

[0079] In addition, the sensor 20 is configured to periodically measure the acceleration of the wheel 10, to which the sensor 20 belongs, along the axis of rotation of the wheel 10.

[0080] The sensor 20 is also configured to detect the distance of the wheel 10 from the vehicle 1, if the absolute value of the variation in the measured acceleration is greater than a predetermined acceleration variation threshold. In the present case, the acceleration variation threshold is for example equal to 0.4g and its value is recorded in the memory area of ​​the sensor 20.

[0081] According to another example, the sensor 20 is configured to detect the distance from the wheel 10 if the absolute value of the difference between at least one measured acceleration value and a predetermined reference acceleration value is greater than the predetermined acceleration variation threshold.

[0082] The reference acceleration value is notably determined by the sensor 20.

[0083] According to yet another example, the sensor 20 is configured to detect the distance of the wheel 10 if the absolute value of the measured acceleration is greater than a predetermined acceleration threshold. In the present case, the predetermined acceleration threshold is in particular equal to 1.5 g and its value is recorded in the memory area of ​​the sensor 20.

[0084] In the event of detection of the distance of the wheel 10, the sensor 20 is configured to send at least one distance detection signal to the computer 30 via the first communication link.

[0085] According to another example, in the event of detection of the distance of the wheel 10, the sensor 20 is configured to send a wheel 10 theft alert to the driver or user of the vehicle 1 whose wheel 10 has been stolen. For example, the sensor 20 is connected to the telephone of the driver or user of the vehicle 1 via a Bluetooth® communication link, and sends a message via said Bluetooth® communication link.

[0086] The sensor 20 is configured to operate in the lifting mode as long as lifting is detected, or for a predetermined duration, between 3 and 30 minutes, preferably between 4 and 5 minutes.

[0087] The computer 30 is notably mounted in the vehicle 1, for example in the dashboard, or in a central armrest, or even in the ceiling light of the vehicle 1.

[0088] As described previously, the computer 30 comprises a reception module, capable of receiving signals sent by the sensor 20 via the first communication link, and a memory area.

[0089] In addition, the computer 30 is connected to at least one warning device such as the horn, the position lights, dipped beam, main beam, etc.

[0090] The computer 30 is configured to detect a stationary position of the vehicle. In other words, the computer 30 detects that the vehicle 1 is parked and that the vehicle 1 is not simply temporarily stopped. For this, the computer 30 detects when the vehicle 1 is stopped and / or when the openings of the vehicle 1 are locked by the driver, then the computer 30 detects when the vehicle 1 is stopped, and therefore immobile, for a duration greater than the transition duration dt.

[0091] In another embodiment, the computer 30 is configured to verify that the vehicle 1 is in a stationary position based on the temperature outside the vehicle 1. For this, the computer 30 is connected to an outside temperature sensor, previously mounted in the vehicle 1. The outside temperature sensor is configured to measure the temperature outside the vehicle 1 and to send the at least one measured outside temperature value to the computer 30.

[0092] From said received outside temperature value, the computer 30 is configured to determine the temperature in the tire, since the temperature in the tire is equal to the outside temperature to which a compensation value, positive or negative, predefined and known by the computer 30 is added. If the temperature value in the tire is lower than the predefined rest temperature, then the computer 30 is configured to confirm that the vehicle 1 is in a stationary position.

[0093] In addition, the computer 30 is configured to receive a presence signal sp sent by at least one sensor 20, via their respective first wireless communication link. For each presence signal sp received, the computer 30 is configured to identify which sensor 20 sent the presence signal sp from the identifier included in the presence signal.

[0094] For each presence signal sp received, the computer 30 is also configured to measure the value of the reference power PRssi_ref, in particular by measuring the power, and in particular the RSSI power, of the presence signal sp received. In addition, the computer 30 is configured to record, in its memory area, the value of the measured reference power PRssi_ref. Thus, for each wheel 10 whose sensor 20 has sent a presence signal sp, the computer 30 knows the value of the reference power PRSsi_ref-

[0095] In addition, for each presence signal sp received, the computer 30 is also configured to record in its memory zone the value of the initial reference internal pressure Pref_init and the value of the initial reference temperature Tref init included in the presence signal sp received.

[0096] Thus, the calculator 30 knows for each wheel 10 whose sensor 20 has sent a presence signal sp, the value of the initial reference internal pressure Pref_inn, the value of the initial reference temperature Tref initet and the value of the reference power PRSSi_ref-

[0097] The calculator 30 is also configured to check the consistency of the value of the initial reference internal pressure Pref_init, of the value of the initial reference temperature Tref init and of the value of the reference power PRSSi_ref recorded for each sensor 20.

[0098] The value of the initial reference internal pressure Pref initest is consistent if it is greater than the predefined minimum inflation threshold. This means that the tire is sufficiently inflated. The predefined minimum inflation threshold is recorded in the memory area of ​​the computer 30.

[0099] The value of the initial reference temperature Tref_init is consistent if it is lower than the predefined rest temperature, for example equal to 40°C, said value of the rest temperature being notably recorded in the memory zone of the cal- culator 30.

[0100] Thus, the computer 30 checks here that the tire pressure is not influenced by a high temperature.

[0101] The value of the reference power PRSsi_ref is consistent if it is greater than the predefined reference power threshold. The reference power threshold is for example predefined at - 85 dBm and its value is recorded in the memory area of ​​the computer 30.

[0102] Different embodiments of the computer 30 will now be described, configured to detect the lifting of the vehicle 1 and / or the moving away of a wheel 10 relative to the vehicle 1.

[0103] According to the first embodiment of the computer 30, the receiving module of the computer 30 is also configured to periodically receive a lifting detection signal sent by at least one sensor 20, via the first communication link. In addition, for each lifting detection signal received, the computer 30 is configured to identify to which wheel 10 the sensor 20 having sent the lifting detection signal belongs from the identifier of the lifting detection signal received.

[0104] Furthermore, the computer 30 understands that the lifting of the vehicle 1 is detected, from the lifting information included in the at least one lifting detection signal received.

[0105] The computer 30 is also configured to measure the power of each lifting detection signal received.

[0106] The computer 30 is configured to detect the distance of the wheel 10, the sensor 20 of which has sent a lifting detection signal, relative to the vehicle 1, if the absolute value of the difference between the measured power value of said lifting detection signal and the predetermined reference power value PRSSi_ref, corresponding to said wheel 10, is greater than a predetermined power variation threshold.

[0107] The predetermined power variation threshold is in particular equal to 30 dBm. The value of the power variation threshold is in particular recorded in the memory area of ​​the computer 30.

[0108] According to another example, the computer 30 is configured to detect the distance from the wheel 10 if the value of the measured power is less than a predetermined power threshold. In other words, the computer 30 detects the distance from the wheel 10, when it detects the reduction in the power of the lifting detection signals sent by the sensor included in said wheel 10. In this case, the predetermined power threshold is in particular equal to -95 dBm. The value of the power threshold is in particular recorded in the memory area of ​​the computer 30.

[0109] According to the second embodiment of the computer 30, the computer 30 is configured to receive a lifting detection signal sent by at least one sensor 20. The computer 30 is then configured to periodically transmit, for example every 4 seconds, a response signal, via the second communication link, to each sensor 20 having sent a lifting detection signal. The computer 30 is then configured to receive a distance detection signal sent by at least one sensor 20, signifying that the wheel 10 comprising said sensor 20 is moving away from the vehicle 1, in other words, that the wheel 10 has been stolen.

[0110] According to the third embodiment of the computer 30, the computer 30 is configured to receive a lifting detection signal sent by at least one sensor 20.

[0111] The computer 30 is configured to periodically receive an acceleration value measured and sent by each sensor 20 having in particular previously sent a lifting detection signal.

[0112] The computer 30 is also configured to detect the distance of a wheel 10, from the at least one measured acceleration value sent by the sensor 20 mounted in said wheel 10. More precisely, the computer 30 detects the distance of the wheel 10 if the absolute value of the variation of the measured acceleration, in other words the absolute value of the difference between two measured acceleration values ​​received successively by the computer 30, is greater than a predetermined acceleration variation threshold, for example equal to 0.4g. The value of the acceleration variation threshold is in particular recorded in the memory area of ​​the computer 30.

[0113] According to another example, the computer 30 detects the distance from the wheel 10 if the absolute value of the difference between at least one measured acceleration value received and a predetermined reference acceleration value is greater than a predetermined acceleration variation threshold.

[0114] The reference acceleration value is notably determined by the sensor 20 and sent by the sensor 20 to the computer 30.

[0115] The predetermined acceleration variation threshold is for example equal to 0.4g and its value is notably recorded in the memory zone of the computer 30.

[0116] According to yet another example, the computer 30 is configured to detect the distance from the wheel 10 if the absolute value of at least one measured acceleration value is greater than a predetermined acceleration threshold. In the present case, the predetermined acceleration threshold is equal to 1.5 g.

[0117] According to the fourth embodiment of the computer 30, the computer 30 is configured to receive at least one distance detection signal sent by at least one sensor 20 signifying that the wheel 10, to which the sensor 20 belongs, is moving away from the vehicle 1, in other words, that the wheel 10 has been stolen.

[0118] If the computer 30 receives a signal detecting the distance of at least one wheel 10 or if the computer 30 itself detects the distance of at least one wheel 10, then the computer 30 is configured to alert of the theft of said wheel 10.

[0119] In particular, the computer 30 is configured to alert in the close environment of the vehicle 1, in particular by sending an activation signal to the vehicle lights and / or to the horn in order to activate the vehicle lights 1 and / or the horn and to scare off the thief in action.

[0120] In addition, the computer 30 is also configured to remotely alert the owner and / or user of the vehicle 1 of the theft of a wheel 10, in particular by sending an alert signal. For example, the alert signal may be a message sent to the telephone of the owner and / or user of the vehicle 1, or a voice message left on the answering machine of the telephone of the owner and / or user of the vehicle 1.

[0121] An alert signal may also be sent to a remote third party, for example an insurance company or the police.

[0122] With reference to [Fig.2], an embodiment of the method according to the invention will now be presented, implemented by the vehicle 1 as presented previously.

[0123] In order to simplify the description, the method will be described for a vehicle 1 of which only one wheel 10 comprises a sensor 20.

[0124] In the case where each wheel 10 comprises a sensor 20, the method is repeated for each sensor 20.

[0125] The method firstly comprises a step E0 of detecting the stationary position of the vehicle 1. The stationary position of the vehicle 1 corresponds to the fact that the vehicle 1 is actually parked, and that the stop is not a temporary stop of the vehicle 1.

[0126] To do this, during this step, the computer 30 and the sensor 20 verify that the stopping time of the vehicle 1 is greater than the predefined transition duration dt.

[0127] Furthermore, when the vehicle 1 moves, the temperature of each tire increases significantly. Thus, in order to verify that the vehicle 1 is in a stationary position, the sensor 20 and / or the computer 30 check(s) that the temperature of the tire is lower than the predefined resting temperature.

[0128] When the sensor 20 has detected that the vehicle 1 is in a stationary position, said sensor 20 measures the value of the initial reference internal pressure Pref_init in the tire of the wheel 10.

[0129] Similarly, the sensor 20 measures the value of the initial reference temperature T refjnit in the tire of the wheel 10.

[0130] The method also comprises a step E01 of transmitting a presence signal sp by the sensor 20 to the computer 30 on the first communication link. The presence signal sp is in particular a radiofrequency signal and includes in particular an identifier, the value of the initial reference internal pressure Pref init determined, the value of the initial reference temperature Tref init, and information indicating to the computer 30 that the sensor 20 has detected that the vehicle 1 is in a stationary position.

[0131] The method then includes a step E02 of reception by the computer 30 of the presence signal sp.

[0132] The method then comprises a verification step E03, by the computer 30, of the identifier of the presence signal sp received. The verification step E03 allows the computer 30 to determine by which sensor 20, and therefore from which wheel 10, the presence signal sp was emitted, in particular when a plurality of wheels 10 of the vehicle 1 comprises a sensor 20.

[0133] Thus, the following steps of the method relate to said sensor 20 having sent the presence signal sp, and therefore relate to the wheel 10 comprising said sensor 20.

[0134] In addition, the method comprises a step E04 of measurement by the calculator 30 of the reference power PRssi_ref, by measuring the power, and in particular the RSSI power, of the presence signal sp received.

[0135] In addition, the method comprises a step E05 of recording the value of the initial reference internal pressure Prefjmtet and the initial reference temperature value Tref_init, included in the presence signal sp, in the memory zone of the computer 30. The value of the initial reference internal pressure Pref initet and the value of the initial reference temperature Tref init relate to the tire of the wheel 10 comprising the sensor 20 having sent said presence signal sp.

[0136] In addition, the recording step E05 also comprises the recording of the reference power PRSsi_ref, relating to said presence signal sp and therefore to the wheel 10 comprising the sensor 20, measured by the computer 30, in the memory area of ​​the computer 30.

[0137] The method then comprises a step of verifying the consistency E06 of the value of the initial reference internal pressure Pref_init, of the initial reference temperature Tref initet and of the reference power PRSsi_ref-

[0138] The value of the initial reference internal pressure Pref initest is consistent if it is greater than the predefined minimum inflation threshold. The value of the initial reference temperature Tref initest is consistent if it is lower than the predefined rest temperature, for example equal to 40 °C. The value of the reference power PRssi_ref is consistent if it is greater than the predefined reference power threshold, for example equal to - 85 dBm.

[0139] The method also comprises a step E001 of verifying the inflation of the tire of the wheel 10 by the sensor 20. For this, the sensor 20 measures the internal pressure Pi0 in the tire and checks that the value of the measured internal pressure Pio is greater than the minimum inflation threshold.

[0140] The method then comprises a step of verifying the stability of the temperature El in the tire of the wheel 10 to which the sensor 20 belongs.

[0141] During this step, the sensor 20 checks the stability of the temperature in the tire. For this, the sensor 20 measures the value of the temperature in the tire. The sensor 20 determines that the temperature is stable when the absolute value of the difference between the temperature measured in the tire and the initial reference temperature Tref init determined for said tire is lower than the predefined temperature threshold, for example equal to 3°C.

[0142] The sensor 20 can also determine the reference temperature value Tref, by measuring the temperature in the tire, for example every 30 or 60 seconds. The reference temperature Tref corresponds to an update of the value of the initial reference temperature Trefjnit.

[0143] Similarly, when a reference temperature value Tref has been measured, the sensor 20 is configured to re-check the stability of the temperature, by measuring the temperature value in the tire again. The sensor 20 then determines that the temperature is stable when the absolute value of the difference between the temperature measured in the tire and the reference temperature Tref determined for said tire, is lower than the predefined temperature threshold.

[0144] During the lifting detection step E2, the sensor 20 operates according to the monitoring mode, and periodically measures, for example every 4 seconds, the internal pressure Pi0 of the tire of the wheel 10. If the absolute value of the difference between the measured internal pressure value Pi0 and the initial reference internal pressure value Pref init predetermined is greater than the predetermined pressure difference threshold, then the sensor 20 detects the lifting of the vehicle 1.

[0145] In this way, the sensor 20 detects a decrease in the internal pressure Pi0 in the tire.

[0146] The sensor 20 also periodically measures the reference internal pressure value Pref, for example by measuring the internal pressure of the tire every 30 seconds or every 60 seconds. The reference internal pressure value Pref corresponds in particular to the update of the initial reference internal pressure value Pref_init.

[0147] Similarly, when the sensor 20 has measured a new value of the reference internal pressure Pref, the sensor 20 again measures the internal pressure Pi0 and detects the lifting of the vehicle 1 if the absolute value of the difference between the measured internal pressure value Pi0 and the predetermined reference internal pressure value Pref is greater than the predetermined pressure difference threshold.

[0148] After detecting the lifting of the vehicle 1, the method comprises a step of activating the lifting mode E3 of the sensor 20, said activation step being defined over the predetermined duration or as long as the lifting of the vehicle 1 is detected.

[0149] According to a first embodiment of the method, the method is implemented by the first embodiment of the sensor 20 and the first embodiment of the computer 30. The first embodiment of the method comprises a step of periodic transmission E3-10 of a lifting detection signal by the sensor 20 to the computer 30, via the first communication link.

[0150] The method then comprises a step of periodic reception by the computer 30 of the lifting detection signals sent by the sensor 20.

[0151] For each lifting detection signal received by the computer 30, the method then comprises a step E3-11 of measuring by the computer 30 the power of the lifting detection signal.

[0152] After the measurement step E3-11, the method may comprise a step of detecting the distance E3-12 of the wheel 10 relative to the vehicle 1, by the computer 30. For example, the computer 30 detects the distance of the wheel 10 when the absolute value of the difference between the measured power value and the value of the reference power PRssi_refpredetermined is greater than the predetermined power variation threshold.

[0153] According to another example, the computer 30 detects the distance of the wheel 10 if the value of the measured power is lower than the predetermined power threshold.

[0154] According to a second embodiment of the method, the method is implemented by the second embodiment of the sensor 20 and the second embodiment of the computer 30. The second embodiment of the method comprises a step E3-20 of transmitting at least one lifting detection signal by the sensor 20 to the computer 30, via the first communication link.

[0155] The method then comprises a step of receiving the lifting detection signal by the computer 30.

[0156] After receiving the lifting detection signal, the method comprises a step of periodic transmission E3-21 by the computer 30 of a response signal to the sensor 20, via the second communication link.

[0157] The method then comprises a step of reception by the sensor 20 of each response signal. For each response signal received by the sensor 20, the method comprises a step E3-22 of measurement of the power of the response signal, by the sensor 20.

[0158] The method comprises a step of detecting the distance E3-23 of the wheel 10 relative to the vehicle 1 by the sensor 20. For example, the sensor 20 detects the distance of the wheel 10 when the absolute value of the difference between at least a measured power value and the second predetermined reference power value P Rssi_ref2 is greater than the second predetermined power variation threshold.

[0159] According to another example, the sensor 20 detects the distance from the wheel 10 if the value of the measured power is lower than the second predetermined power threshold.

[0160] After detecting the distance of the wheel 10, the method comprises a step of sending a distance detection signal by the sensor 20 to the computer 30. The computer 30 then receives the distance detection signal sent by the sensor 20.

[0161] According to a third embodiment of the method, the method is implemented by the third embodiment of the sensor 20 and the third embodiment of the computer 30. The third embodiment of the method comprises a step of sending, by the sensor 20 to the computer 30, a lifting detection signal, signifying to the computer 30 that the lifting of the vehicle 1 has been detected.

[0162] The method then comprises a step of periodic measurement of the acceleration E3-30 by the sensor 20.

[0163] The method then comprises a step E3-31 of sending by the sensor 20 each measured acceleration value to the computer 30. The method therefore also comprises a step E3-32 of receiving by the computer 30 each measured acceleration value.

[0164] The method then comprises a step of detecting the distance E3-33 from the wheel 10, by the computer 30 from at least one measured acceleration value received.

[0165] For this, the computer 30 detects the distance of the wheel 10 if the absolute value of the variation in the measured acceleration is greater than a predetermined acceleration variation threshold.

[0166] In another embodiment, the computer 30 detects the distance from the wheel 10 if the absolute value of the difference between a received measured acceleration value and the predetermined reference acceleration value is greater than a predetermined acceleration variation threshold.

[0167] According to yet another example, the computer 30 detects the distance from the wheel 10 if the absolute value of at least one measured acceleration value is greater than the predetermined acceleration threshold.

[0168] In addition, the reference acceleration value is determined in particular by the sensor 20. The sensor 20 then sends the determined reference acceleration value to the computer 30.

[0169] According to a fourth embodiment of the method, the method is implemented by the fourth embodiment of the sensor 20 and the fourth embodiment of the calculator 30. The fourth embodiment of the method may comprise a step of sending, by the sensor 20 to the calculator 30, a lifting detection signal, signifying to the calculator 30 that the lifting of the vehicle 1 has been detected.

[0170] The method then comprises a step of periodic measurement of the acceleration E3-40, by the sensor 20.

[0171] The method then comprises a step of detecting the distance E4-41 from the wheel 10, by the sensor 20, from at least one measured acceleration value. For this, the sensor 20 detects the distance from the wheel 10 if the absolute value of the variation in the measured acceleration is greater than the predetermined acceleration variation threshold.

[0172] According to another example, the sensor 20 detects the distance from the wheel 10 if the absolute value of the difference between a measured acceleration value and a predetermined reference acceleration value is greater than the predetermined acceleration variation threshold.

[0173] In addition, before the step of detecting the distance E4-41 from the wheel 10, the sensor 20 determines the reference acceleration value.

[0174] According to yet another example, the sensor 20 detects the distance from the wheel 10 if the absolute value of at least one measured acceleration value is greater than the predetermined acceleration threshold.

[0175] After detecting the distance of the wheel 10, the method comprises a step of sending a distance detection signal by the sensor 20 to the computer 30. The computer 30 therefore then receives the distance detection signal sent by the sensor 20.

[0176] After detecting the distance of the wheel 10, the method comprises a step of alerting of a theft E4 of the wheel 10, comprising said sensor 20.

[0177] According to the first embodiment and the third embodiment of the method, during the step of alerting a theft E4, the computer 30 alerts in the environment close to the vehicle 1 and remotely.

[0178] More precisely, in the close environment of the vehicle 1, the computer 30 sends an activation signal to the vehicle lights and / or to the horn in order to activate the vehicle lights 1 and / or the horn and to scare off the thief of the wheel 10.

[0179] Remotely, the computer 30 alerts in particular the owner or driver of the vehicle 1, in particular by an SMS sent to the mobile phone of the owner or driver, or by a voice message left on the answering machine of said phone. Furthermore, the computer 30 can also alert the insurance of the vehicle 1 or the police.

[0180] According to the second embodiment and the fourth embodiment of the method, following receipt of the distance detection signal by the computer 30, the computer 30 alerts in the environment of the vehicle 1 and remotely, as described previously.

[0181] Thus, advantageously, the method as described, implemented by a computer 30 and at least one sensor 20 as described previously, make it possible to detect the theft of a wheel 10 of a vehicle 1 and to warn the owner or driver of said vehicle 1 if necessary.

Claims

Claims

1. Method for alerting theft of a wheel (10) of a motor vehicle (1), said vehicle (1) comprising a plurality of wheels (10) and a computer (30), at least one of the wheels (10) comprising a sensor (20), said method comprising, for the at least one wheel (10), the steps of: - measuring at least one value of the internal pressure (Pi0) of the tire of the wheel (10), - detecting the lifting of the vehicle (1) when the absolute value of the difference between the at least one measured internal pressure value (Pi0) and a predetermined reference internal pressure value (Pref, Pref_init) is greater than a predetermined pressure difference threshold, - when the lifting of the vehicle (1) is detected, detecting the distance of the wheel (10), - when the distance of the wheel (10) is detected, alerting the theft of the wheel (10),said method being characterized in that the step of detecting the distance of the wheel (10) comprises the steps of: - in a so-called "lifting" mode, periodic emission by the sensor (20) of a lifting detection signal to the computer (30) as long as the lifting of the vehicle (1) is detected, - reception by the computer (30) of said emitted lifting detection signal, - measurement of the power of the received lifting detection signal, - detection of the distance of the wheel by the computer (30) if at least one measured power value is lower than a predetermined power threshold.,

2. The method of claim 1, wherein the at least one emitted lifting detection signal is a radio frequency type signal.

3. Method according to any one of the preceding claims, in which the computer (30) is configured to send an alert signal to the user of the vehicle (1) in the event of theft of the wheel (10).

4. Computer program product characterized in that it comprises a set of program code instructions which, when executed by one or more processors, configure the processor(s) to implement a method according to one of claims 1 to 3.

5. Motor vehicle (1), said vehicle (1) comprising a plurality of wheels (10) and a computer (30), at least one of the wheels (10) comprising a sensor (20), the computer (30) and the at least one sensor (20) being configured to implement the method according to any one of claims 1 to 3.

6. Sensor (20) for a motor vehicle, said vehicle (1) comprising a plurality of wheels (10) and a computer (30), said sensor (20) being intended to be mounted in a wheel (10) of said vehicle (1), said sensor (20) being configured to: - measure at least one value of the internal pressure (P10) of the tire of the wheel (10), - detect the lifting of the vehicle (1) if the absolute value of the difference between the at least one measured internal pressure value (P10) and a predetermined reference internal pressure value (Pref, Pref_init) is greater than a predetermined pressure difference threshold, - emit a lifting detection signal to the computer (30), - according to a lifting mode, periodically measure the acceleration along the axis of rotation of the wheel (10), - detect the distance of the wheel (10) if the absolute value of the variation in the measured acceleration is greater than a predetermined acceleration variation threshold.

7. Sensor (20) according to the preceding claim, configured to send an alert signal to the user of the vehicle (1) in the event of theft of the wheel.

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