Method for detecting an intruder object under a motor vehicle
The TPMS method uses Bluetooth-equipped wheel units to detect intruder objects by signal comparison, addressing safety and charging issues by preventing vehicle startup or charging if intruder presence is detected.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-03-19
- Publication Date
- 2026-03-06
AI Technical Summary
Existing tire pressure monitoring systems (TPMS) fail to detect the presence of intruder objects, such as animals or other objects, under a motor vehicle, particularly at the time of vehicle startup or inductive charging, which can lead to safety issues and disruption of charging processes.
A method utilizing a tire pressure monitoring system with wheel units equipped with Bluetooth communication devices to transmit and receive probe signals, comparing these signals with reference signals to detect differences indicative of intruder presence through power and phase variations, preventing vehicle startup or charging if an intruder is detected.
Enables detection of intruder objects without visual inspection, ensuring safe vehicle operation and preventing charging disruptions by identifying intruder presence through signal analysis.
Smart Images
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Abstract
Description
Title of the invention: Method for detecting an intruder object under a motor vehicle technical field
[0001] The present patent application relates to a method for detecting an intruder object under a motor vehicle which is equipped with a tire pressure monitoring system. Previous technique
[0002] For safety purposes, it is known to equip a motor vehicle with a monitoring system known as "TPMS", an English acronym for "Tyre Pressure Monitoring System", or in French "Système de Surveillance de la Pression des Pneumatiques".
[0003] Such a monitoring system, which is described for example in document FR3045498, generally comprises a central computing unit mounted on the vehicle and wheel units which each equip an associated wheel of the vehicle.
[0004] The central unit includes an electronic computer known as the "ECU", an English acronym for "Electronic Control Unit".
[0005] Also, the vehicle's central unit is equipped with a radio receiver adapted to communicate with each wheel unit.
[0006] Each wheel unit is responsible for regularly acquiring the physical quantities representative of the operating parameters of the associated wheel, in particular to detect an anomaly of the associated wheel.
[0007] Also, each wheel unit emits messages to the vehicle's central unit containing pressure, temperature and acceleration data of the associated wheel, as well as an identification code for the emitting wheel unit.
[0008] For this purpose, each wheel unit includes a tire inflation pressure sensor, a temperature sensor, an accelerometer and a radio transmitter.
[0009] In addition, each wheel unit is equipped with a battery for power supply and a microcontroller comprising a data storage memory and a microprocessor.
[0010] Upon receipt of this data by the vehicle's central unit, in the event of a significant pressure difference compared to the pressure recommended by the manufacturer, the TPMS system will warn the vehicle driver of underinflation of one of the wheels, by means of an alert message displayed on the vehicle's dashboard, for example.
[0011] A remaining technical problem is the detection of the presence of an intruder object under the motor vehicle.
[0012] The intruder is for example a living being, and more particularly an animal, which has slipped under the vehicle before or after the driver gets behind the wheel.
[0013] However, when starting the motor vehicle, the driver is not able to know if there is an intruder object under the car.
[0014] Even if a visual check is carried out by the driver, this is not sufficient because there is a latency period between the time the check is carried out and the time the vehicle is started, a time during which an animal may position itself under the vehicle.
[0015] Similarly, with regard to electric motor vehicles which are equipped with a battery recharged by induction, care is taken to avoid the presence of an intruder object under the vehicle in order to avoid harming that object if it is a living being.
[0016] Indeed, exposure to electromagnetic fields can have undesirable biological effects on living beings.
[0017] Also, we seek to avoid the presence of an intrusive object which is arranged under the electric vehicle and which is interposed between the induction charger and the vehicle, in order to avoid disrupting the charging of the vehicle by induction. Description of the invention
[0018] The object of the present invention is to solve the problem of detecting the presence of an intruder object under a motor vehicle, in particular at the time of starting the vehicle or at the time of inductive charging of the vehicle.
[0019] This objective, as well as others that will become apparent from the following description, is achieved with a method for detecting an intruder object under a motor vehicle equipped with a tire pressure monitoring system, said system comprising at least: • a first wheel unit which is fitted to the first wheel of the motor vehicle and which includes a first radio communication device comprising a transmitter and a receiver, • a second wheel unit fitted to a second wheel of the motor vehicle and comprising a second communication device including a radio transmitter and receiver, and • a central unit comprising a computer and a communication device suitable for communicating with each of said wheel units, characterized in that it comprises at least: • a probing step which successively comprises a transmission phase consisting of transmitting at least one probe signal from the first wheel unit to the second wheel unit, through a transmission channel extending between the first and second wheel units, followed by a phase of reception of said probe signal by the second wheel unit, and • an analysis step which consists of comparing and measuring differences in properties between said probe signal received by the second wheel unit and a previously defined reference signal, and determining whether said measured differences are characteristic of the presence of an intruder object present on said transmission channel used by said probe signal.
[0020] Thus, the present invention makes it possible to detect an intruder object present under the vehicle without having to get out of the vehicle to check visually.
[0021] According to other optional features of the invention, taken alone or in combination:
[0022] - the properties measured during the analysis step relate to the variation of power as a function of the probe signal frequency;
[0023] - the properties measured during the analysis step relate to the variation of phase as a function of the probe signal frequency;
[0024] - the method includes a step of determining the reference signal which is carried out at least once before the sounding stage and which successively includes a transmission phase which consists of emitting the sounding signal from the first wheel unit to the second wheel unit through said transmission channel, then a phase of reception and recording of the sounding signal received by the second wheel unit as said reference signal;
[0025] - the communication devices of each wheel unit and of the central unit function They operate according to the Bluetooth® standard. Indeed, the Bluetooth® standard allows bidirectional communication between two devices;
[0026] - in a minimal embodiment of the invention, the first wheel unit and the second wheel unit are arranged diagonally on the motor vehicle, so that the transmission channel that separates them passes through the middle of the vehicle;
[0027] - the motor vehicle comprises four wheel units, each of which is fitted to a wheel of the vehicle, the emission phase of the probing step consisting of emitting at least one probe signal from each wheel unit to each of the other three wheel units, and the analysis step consisting of comparing and measuring differences in properties between the probe signal received by each wheel unit with a previously defined associated reference signal, and determining whether said measured differences are characteristic of the presence of an intruder object present on the transmission channel used by the probe signal concerned;
[0028] - the process is executed by the motor vehicle when a procedure of The start-up of said vehicle is detected;
[0029] - said motor vehicle is an electric motor vehicle powered by a battery, said process being carried out during an induction charging procedure The battery is detected.
[0030] The invention also relates to a motor vehicle which includes at least one central unit and two wheel units duly programmed to implement the method described above. Brief description of the drawings
[0031] Other features, purposes and advantages of the invention will become apparent from the following detailed description, for the understanding of which reference should be made to the accompanying drawings in which:
[0032] [Fig-1] Fig. 1 is a schematic top view of a motor vehicle equipped with a central unit and four wheel units duly programmed to implement the process according to the invention;
[0033] [Fig.2] The [Fig.2] is a graph with the x-axis representing the communication channels graduated in megahertz (MHz) and the y-axis graduated in decibels (dB), representing the power variation as a function of the frequency of the reference signal received by the second wheel unit and emitted by the first wheel unit;
[0034] [Fig.3] The [Fig.3] is a graph similar to that of the [Fig.2], representing the variation of power as a function of the frequency of the probe signal received by the second wheel unit and emitted by the first wheel unit;
[0035] [Fig.4] The [Fig.4] is a graph with the x-axis representing the communication channels graduated in megahertz (MHz) and the y-axis graduated in degrees of angle (°), representing the phase variation as a function of the frequency of the reference signal received by the second wheel unit and emitted by the first wheel unit;
[0036] [Fig.5] The [Fig.5] is a graph similar to that of the [Fig.4], representing the phase variation as a function of the frequency of the probe signal received by the second wheel unit and emitted by the first wheel unit;
[0037] [Fig.6] The [Fig.6] is a flowchart which illustrates the sequence of steps of the process according to the invention.
[0038] Throughout all these figures, identical or similar elements are identified by identical or similar reference signs. Description of the implementation methods
[0039] A motor vehicle 10 according to the invention is schematically represented in [Fig.1], comprising a central unit 12 and four wheels 14a, 14b, 14c, 14d, each equipped with a wheel unit 16a, 16b, 16c, 16d respectively.
[0040] To avoid making the description cumbersome, only the first wheel unit 16a is described hereafter, the four wheel units 16a, 16b, 16c, 16d having a similar design and operation.
[0041] The wheel unit 16a belongs to a tire pressure monitoring system matics known by the English acronym "TPMS", for "Tire Pressure Monitoring System".
[0042] The wheel unit 16a includes a housing which contains a microcontroller equipped with a processor, a battery, a memory and a set of sensors dedicated to measuring operating parameters of the wheel unit 16a.
[0043] This set of sensors includes, for example, a temperature sensor and a pressure sensor capable of measuring the inflation pressure of the tire of the associated wheel 14a.
[0044] The measurements taken by the sensors can be transmitted to the central unit 12 of the motor vehicle 10.
[0045] For this purpose, the wheel unit 16a includes a radio communication device 18 which includes a transmitter 20 and a receiver 22.
[0046] Similarly, the central unit 12 includes a radio communication device 24 which is adapted to communicate with each of the wheel units 16a, 16b, 16c, 16d and which includes a transmitter 26 and a receiver 28.
[0047] According to one embodiment, the communication device 18 of each wheel unit 16a, 16b, 16c, 16d and the communication device 24 of the central unit 12 operate according to the Bluetooth® standard which allows bidirectional data exchange over short distances using radio waves.
[0048] In addition, the central unit 12 of the motor vehicle 10 includes an electronic computer 30 and a memory 32.
[0049] In this example of an embodiment of the invention, the motor vehicle 10 is an electric motor vehicle powered by a battery (not shown).
[0050] The invention relates to a method for detecting an intruder object located under the motor vehicle 10, the sequence of steps of which is illustrated in [Fig.6].
[0051] The term "intruder object" means both a living being, such as an animal, and an inanimate object.
[0052] The method according to the invention comprises a first sounding step El which successively comprises an emission phase followed by a reception phase.
[0053] The emission phase consists of emitting a probe signal successively from each wheel unit 16a, 16b, 16c, 16d, to each of the other three wheel units 16a, 16b, 16c, 16d.
[0054] The reception phase consists of receiving the probe signal emitted successively by each wheel unit 16a, 16b, 16c, 16d, by each of the three other wheel units 16a, 16b, 16c, 16d.
[0055] The wheel units 16a, 16b, 16c, 16d are connected in pairs by a transmission channel through which the signals are transmitted.
[0056] The expression "transmission channel" refers to the path through which the data are transmitted between a transmitter and a receiver.
[0057] In the context of Bluetooth® type communication according to the invention, the transmission channel is the path through which radio signals pass between the connected wheel units 16a, 16b, 16c, 16d.
[0058] As can be seen in [Fig. 1], a first channel C1 extends between the first wheel unit 16a and the second wheel unit 16b, a second channel C2 extends between the first wheel unit 16a and the third wheel unit 16c, a third channel C3 extends between the first wheel unit 16a and the fourth wheel unit 16d, a fourth channel C4 extends between the second wheel unit 16b and the fourth wheel unit 16d, a fifth channel C5 extends between the second wheel unit 16b and the third wheel unit 16c and a sixth channel C6 extends between the third wheel unit 16c and the fourth wheel unit 16d.
[0059] According to a preferred embodiment of the invention, the first sounding step El consists of performing a "channel sounding" function which is known under the English terminology "channel sounding" and which is specific to Bluetooth® technology.
[0060] The "channel sounding" function is generally implemented to measure the quality and conditions of the transmission channel, including interference, noise, and other parameters.
[0061] The first probing step El is followed by a second analysis step E2 which consists of comparing and measuring differences in properties between the probe signal received by each wheel unit 16a, 16b, 16c, 16d with a previously defined reference signal which is associated with each receiving wheel unit 16a, 16b, 16c, 16d.
[0062] This second analysis step E2 is carried out by the calculator 30 of the central unit 12.
[0063] For this purpose, the probe signal to be analyzed is transmitted by radio communication to the central unit 12, which analyzes said probe signal with the corresponding reference signal which is recorded in the memory 32 of the central unit 12.
[0064] For example, the probe signal received by the second wheel unit 16b and sent from the first wheel unit 16a through the first transmission channel Cl, is compared to the reference signal which is associated with this pair of wheel units 16a, 16b and the associated channel Cl.
[0065] Each reference signal is a signal that is characteristic of an "empty" transmission between the transmitter of a wheel unit 16a, 16b, 16c, 16d and the receiver of another wheel unit 16a, 16b, 16c, 16d, that is to say when the transmission channel used by the signal is not disturbed by the presence of an intruder object.
[0066] Indeed, the transmission channel can be affected by various factors such as radio interference, electromagnetic noise and physical obstacles.
[0067] The analysis step E2 makes it possible to determine whether the differences measured between the probe signal received by the wheel unit 16a, 16b, 16c, 16d concerned with the associated reference signal are characteristic of the presence of an intruder object present on the transmission channel used.
[0068] According to an example of an embodiment of the invention, the properties measured during the analysis step E2 relate to the power variation as a function of the frequency of the receiving probe signal.
[0069] As an example, [Fig.2] shows a graph representing the variation of power as a function of the frequency of the reference signal received by the second wheel unit 16b, and emitted by the first wheel unit 16a.
[0070] Also, [Fig.3] represents a graph similar to that of [Fig.2], representing the variation of power as a function of the frequency of the probe signal received by the second wheel unit 16b, and emitted by the first wheel unit 16a.
[0071] We can observe significant differences between the graph of [Fig.2] and that of [Fig.3], differences which are characteristic of the presence of an intruder object present on the transmission channel Cl used.
[0072] The properties measured during the E2 analysis step also relate to the phase variation as a function of the frequency of the received probe signal; this is referred to as the phase signature.
[0073] By way of example, [Fig.4] shows a graph representing the phase variation as a function of the frequency of the reference signal received by the second wheel unit 16b, and emitted by the first wheel unit 16a.
[0074] In other words, the graph in [Fig.4] represents the phase signature of the reference signal received by the second wheel unit 16b.
[0075] In this embodiment, Bluetooth® communication uses an 80 megahertz frequency band between 2402 and 2480 megahertz, i.e. forty channels spaced two megahertz apart.
[0076] By way of non-limitation, it should be noted that the communication devices 18, 24 can operate according to other technologies which allow information on the transmission channel in amplitude and phase, for example in Wifi or Ultra Wide Band UWB.
[0077] Also, [Fig.5] represents a graph similar to that of [Fig.4], representing the phase variation as a function of the frequency of the probe signal received by the second wheel unit 16b, and emitted by the first wheel unit 16a.
[0078] We can observe significant differences between the graph of [Fig.4] and that of [Fig.5], differences which are characteristic of the presence of an intruder object present on the transmission channel Cl used.
[0079] Preferably, the method according to the invention is carried out by the motor vehicle 10 when a vehicle start procedure is detected.
[0080] Thus, if during the analysis step E2 an intruder object is detected, the starting of the motor vehicle 10 is prevented and / or an alert message is displayed on the vehicle's dashboard.
[0081] Similarly, the method according to the invention can be performed by the motor vehicle 10 when an inductive charging procedure of the vehicle's battery is detected, or during the inductive charging procedure.
[0082] If during the analysis step E2 an intruder object is detected, the charging of the motor vehicle 10 is prevented or suspended, and / or an alert message is displayed on the vehicle's dashboard.
[0083] Finally, the method according to the invention includes a step of determining the reference signal E0 which is carried out before the probing step El.
[0084] For example, the step of determining the reference signal E0 is carried out at the factory when the motor vehicle 10 is equipped with its four wheel units 16a, 16b, 16c, 16d.
[0085] However, the step of determining the reference signal E0 can be carried out during the life of the motor vehicle 10, for example when one or more wheel units 16a, 16b, 16c, 16d are replaced.
[0086] The step of determining the reference signal E0 includes an emission phase which consists of emitting the probe signal successively from each wheel unit 16a, 16b, 16c, 16d, to each of the three other wheel units 16a, 16b, 16c, 16d.
[0087] Also, the step of determining the reference signal E0 includes a reception phase consisting of receiving the probe signal emitted successively by each wheel unit 16a, 16b, 16c, 16d, by each of the three other wheel units 16a, 16b, 16c, 16d.
[0088] This reception phase is followed by a phase of recording the received probe signal as the reference signal, and of associating the reference signal with the relevant pair of wheel units.
[0089] Of course, the step of determining the reference signal E0 is carried out when no intruder object is present under the motor vehicle 10.
[0090] Thus, the method according to the invention makes it possible to detect the presence of an intruder object present under the motor vehicle 10 by scanning a large area between the four wheel units 16a, 16b, 16c, 16d.
[0091] By way of non-limitation, in a minimal configuration of the method according to the invention, the method is carried out between only two wheel units 16a, 16b which are arranged diagonally, so that the transmission channel Cl which separates them passes through the middle of the motor vehicle 10.
[0092] Naturally, the invention is described above by way of example. It is it being understood that a person skilled in the art is able to carry out different variations of the invention without going out of the scope of the invention.
Claims
Demands
1. A method for detecting an intruder object under a motor vehicle (10) which is equipped with a tire pressure monitoring system, said system comprising at least: • a first wheel unit (16a) which is fitted to a first wheel (14a) of the motor vehicle (10) and which comprises a first radio communication device (18) including a transmitter (20) and a receiver (22), • a second wheel unit (16b) which is fitted to a second wheel (14b) of the motor vehicle (10) and which comprises a second communication device including a radio transmitter and receiver, and • a central unit (12) which comprises a computer (30) and a communication device (24) adapted to communicate with each of said wheel units (16a, 16b),characterized in that it comprises at least: • a probing step (E1) which successively comprises an emission phase consisting of transmitting at least one probe signal from the first wheel unit (16a) to the second wheel unit (16b), through a transmission channel (C1) extending between the first wheel unit (16a) and the second wheel unit (16b), then a reception phase of said probe signal by the second wheel unit (16b), and • an analysis step (E2) which consists of comparing and measuring differences in properties between said probe signal received by the second wheel unit (16b) and a previously defined reference signal, and determining whether said measured differences are characteristic of the presence of an intruder object present on said transmission channel (C1) used by said probe signal.
2. A method for detecting an intruder object according to claim 1, characterized in that the properties measured during the analysis step (E2) relate to the power variation as a function of the probe signal frequency.
3. A method for detecting an intruder object according to any one of the previous claims, characterized in that the properties measured during the analysis step (E2) relate to the phase variation as a function of the probe signal frequency.
4. A method for detecting an intruder object according to any one of the preceding claims, characterized in that it comprises a reference signal determination step (EO) which is carried out at least once before the probing step (El) and which successively comprises an emission phase which consists of emitting the probe signal from the first wheel unit (16a) to the second wheel unit (16b) through said transmission channel (Cl), and then a phase of receiving and recording the probe signal received by the second wheel unit (16b) as said reference signal.
5. Method for detecting an intruder object according to any one of the preceding claims, characterized in that the communication devices (18) of each wheel unit (16a, 16b) and of the central unit (12) operate according to the Bluetooth® standard.
6. A method for detecting an intruder object according to any one of the preceding claims, characterized in that the first wheel unit (16a) and the second wheel unit (16b) are arranged diagonally on the motor vehicle (10), so that the transmission channel (Cl) which separates them passes through the middle of the vehicle.
7. A method for detecting an intruder object according to any one of the preceding claims, characterized in that the motor vehicle (10) comprises four wheel units (16a, 16b, 16c, 16d), each of which is fitted to a wheel (14a, 14b, 14c, 14d) of the vehicle, the emission phase of the probing step (E1) consisting of emitting at least one probe signal from each wheel unit (16a, 16b, 16c, 16d) to each of the three other wheel units, and the analysis step (E2) consisting of comparing and measuring differences in properties between the probe signal received by each wheel unit (16a, 16b, 16c, 16d) with a previously defined associated reference signal, and determining whether said measured differences are characteristic of the presence of an intruder object present on the channel (C1, C2, C3, C4, C5, C6) transmission path used by the probe signal in question.
8. A method for detecting an intruder object according to any one of the preceding claims, characterized in that it is executed by the motor vehicle (10) when a start procedure of said vehicle is detected.
9. A method for detecting an intruder object according to any one of the preceding claims, characterized in that said motor vehicle (10) is a battery-powered electric motor vehicle, said method being executed when an inductive charging procedure of the battery is detected.
10. Motor vehicle (10) comprising at least one central unit (12) and two wheel units (16a, 16b) duly programmed to carry out the method according to any one of claims 1 to 9.