Method for automatically calibrating the power of an activation signal of at least one sensor and device for implementing said method

Abstract

The present invention relates to a method (100, 100') for automatically calibrating the power (Pi) of an activation signal (Si) of at least one sensor (C1), in particular a pressure sensor for a tire pressure monitoring system (7) of a motor vehicle (5), said sensor (C1) having an identification number (Id) and comprising at least one data transmitting and receiving module, said method (100, 100') comprising: - the maximum transmission power P of the deactivation signal of said sensor max and the minimum transmission power P of the activation signal of the sensor min Decide (det); said maximum transmission power P max and the minimum transmission power P min When the difference δ between the max and the minimum transmission power P min and are stored in memory (Smem).

Description

[Technical Field]

[0001] The present invention relates to the field of sensors in the automotive sector, in particular to the field of pressure sensors, and to methods for activating and communicating with such sensors.

[0002] The invention more particularly relates to a method for automatically calibrating the power of the activation signal of said sensor and to an activation device making it possible to implement said method.

[0003] The present invention is advantageously applied to pressure sensors located (embedded) or intended to be embedded in automobile tires (e.g., wheel rims and / or tube valves). These pressure sensors are typically paired with the automobile's on-board computer, and the sensors transmit data (e.g., regarding tire pressure and / or temperature levels) to the on-board computer. [Background technology]

[0004] The sensor on-board computer assembly is known as a "Tire Pressure Monitoring System" (TPMS).

[0005] Each pressure sensor is conventionally equipped with a transmitter, e.g., a radio frequency transmitter, to enable data transmission to an onboard computer that receives data from the sensors and can alert the vehicle user if one of the tires is punctured or is currently losing air, creating a safety hazard.

[0006] However, pressure sensors located inside the tire are typically not removable, so changing the wheel involves changing the sensor, but in that case the new sensor is not directly detected by the vehicle's on-board computer.

[0007] When changing tires, the sensors inside the new tires must be paired (or wirelessly linked) with the vehicle's onboard computer. This pairing (or wireless connection) is performed by a dedicated activation device (commonly called a "TPMS tool"). The device activates the sensors, captures and stores relevant data emitted by the sensors, such as the sensor's identifier, and transmits it to the onboard computer. This enables the onboard computer to detect and locate the sensors inside the newly installed tires, pick up their signals, and alert the user in the event of a detected pressure drop in one of the tires.

[0008] The sensor activation device can also be used in an industrial context, i.e. in a manufacturing plant for sensors, in a manufacturing plant for tires when said sensors are mounted on tires, or in a manufacturing plant for automobiles equipped with such tires.

[0009] Thus, in an industrial context, there is a need to activate and test sensors, identify sensors (e.g., for quality monitoring), configure sensors, and / or pair sensors with a vehicle's on-board computer. Summary of the Invention [Problem to be solved by the invention]

[0010] However, factory production lines are often located very close to each other, and multiple sensors may be activated by the activation signal emitted by a matched activation device, so the transmission power of such activation devices needs to be calibrated to avoid undesired sensor reactivation.

[0011] For example, in a factory, vehicle tires and wheels may: - the tires are moving along the conveyor belt and are close enough to each other that an activation signal emitted from an activation device triggers activation of a sensor located inside the tire adjacent to the tire being tested; -Because the vehicle is mounted and the wheels are therefore relatively close to each other, there is a risk of multiple sensors located inside different wheels of the vehicle being activated, this risk being particularly great in the case of vehicles with dual wheels, such as trucks.

[0012] Furthermore, the activation signal emitted by the activation device is a continuous or modulated electromagnetic signal, the frequency of which is typically 125 kHz. Because these electromagnetic signals can potentially pose a risk to human health, it is important to minimize their transmission power (i.e., the energy radiated by the antenna transmitting the radio signal). To achieve this, it is necessary to find a balance between a transmission power value that ensures sensor activation and a transmission power value that minimizes the risk to operators working near the activation device.

[0013] Furthermore, when installing an activation device in an industrial environment, a specialized operator must be called in to configure the device. The efficiency and propagation of the activation signal are closely dependent on the environment in which the activation device is installed (obstacles, echoes, etc.). Therefore, it is necessary to configure the activation device so that the power of the signal received by the sensor is sufficient to activate the desired sensor, e.g., a sensor located at a defined distance on a production line, while at the same time limiting the operator's exposure to the activation signal. [Means for solving the problem]

[0014] The object of the present invention is therefore to solve at least one of the problems mentioned herein above, and is therefore a novel method for automatically calibrating the power of an activation signal of at least one sensor, in particular a pressure sensor for a tire pressure monitoring system of a motor vehicle, said sensor having an identification number and including at least one data transmitting and receiving module, said method being characterized in that it comprises: - the maximum transmission power P of the deactivation signal of said sensor max and the minimum transmission power P of the activation signal of the sensor min determining the said maximum transmission power P max and the minimum transmission power P min When the difference δ between max and the minimum transmission power P min and storing the result in a memory.

[0015] Thus, the transmission power P max An activation signal transmitted with a power below P will not activate the sensor. min An activation signal emitted with a transmit power even slightly greater than will activate the sensor.

[0016] According to one possible characteristic, the maximum power P max and minimum power P min The step of determining the power P max and P min It is stopped when the difference δ between

[0017] According to another possible feature, the power P max ,P min The determination step is carried out by a dichotomous change in the power of the activation signal.

[0018] Dichotomous variation means varying the activation signal power over several iterations to determine a framework of optimal power values ​​for activating one or more sensors under nominal operating conditions.

[0019] According to another possible feature, the emitted activation signal has a maximum power P max and minimum power P min The power P corresponding to the arithmetic mean of i It has.

[0020] In other words, the transmission power of the activation signal P i during the maximum and minimum power determination step,

number

[0021] According to another possible feature, the power P max ,P min The determination step is the power P i , for example by detecting or not detecting at least one response signal from (i.e. emitted by) said at least one sensor according to an activation signal previously emitted by said activation device.

[0022] According to another possible feature, when a response signal is received from said at least one sensor, the power P of the activation signal that activated said sensor is i is the minimum power P min (or the minimum transmit power of the activation signal that will activate the sensor).

[0023] According to another possible feature, if no response signal is received from the at least one sensor, the power P of the activation signal that activated the sensor is i is the maximum power P max (or the maximum power at which the signal does not activate the sensor).

[0024] The response signal is transmitted for a predetermined time T R is considered not to have been received after the time T R is, for example, greater than 5 seconds, preferably greater than 10 seconds. R generally depends on the type of sensor and the environment in which the activation and response signals are propagated.

[0025] According to another possible feature, during the method according to the invention, a waiting time T L There is.

[0026] Indeed, the waiting time L If there is no power P, there is a risk of detecting the activation of the sensor by an activation signal from a previous step or iteration. i-1 Previous launches at Power P i , which will falsify all results. Advantageously, the waiting time is configurable and depends on the type of sensor and the environment in which the sensor is placed, and this waiting time may be set, for example, between 0.5 and 1.5 seconds, and preferably substantially equal to 1 second.

[0027] According to another possible feature, there is an initialization of the method, during which the maximum power P of the non-activating signal is determined. max , the minimum power of the activation signal P min , and / or the maximum power P max and minimum power P min An initial value of the difference δ0 between

[0028] Maximum Power P max , minimum power P min , and the initial value of the power difference δ0 may be default values. For example, the maximum transmission power may correspond to the maximum power at which the initiating device can emit an activation signal, and the minimum transmission power may correspond to the minimum power at which the initiating device can emit an activation signal, while the power difference δ0 is equal to 5% (i.e., the relative difference between the powers at which the initiating device can emit the minimum and maximum signals is equal to 5%).

[0029] Another possible feature is the pre-identification of said sensor by transmitting an activation signal at a predetermined power, for example the maximum transmission power at which the activation device is able to emit a signal.

[0030] According to another possible feature, the identification number of each sensor which emits a signal in response to said identification activation signal is stored in a memory.

[0031] To the extent that multiple sensors are calibrated simultaneously, for example in the case of dual wheels, and therefore sensors located at different spatial locations, the power of the activation signal of each sensor needs to be calibrated, it may be advantageous to associate a location with each sensor identifier and determine whether the sensor has been activated depending on whether a signal has been received from the sensor (following transmission of the activation signal by the activation device).

[0032] Another feature is the association of a sensor (and its identifier) ​​with a location that is determined, for example, depending on the (received) power of a response signal following an activation signal.

[0033] According to another possible feature, the identification number of each sensor is manually pre-stored in memory.

[0034] The invention also relates to a device for activating at least one sensor, in particular a pressure sensor for a vehicle tire pressure monitoring system, The device comprises: - at least one sensor activation module; - a module for receiving signals from the sensor; - an electronic entity configured to store and / or process information carried by the signals emitted by said sensors; a module for communicating with a remote electronic entity, such as an on-board computer of a motor vehicle, in order to transmit the information carried by the received signal; The device, on the other hand, determines a maximum transmission power P of the deactivation signal of the at least one sensor. max and a minimum transmission power P of a signal that will result in activation of said at least one sensor. min and on the other hand, the power P max and P min When the difference δ between the max and minimum power P min The method is characterized in that it is configured to stop the step of determining whether or not the

[0035] According to another possible feature, the sensor is a pressure and / or temperature sensor integrated into a vehicle tire. [Brief explanation of the drawings]

[0036] The invention will be better understood and other objects, details, features and advantages thereof will become more apparent during the following description of particular embodiments of the invention, given purely by way of non-limiting example, with reference to the accompanying drawings, in which: [Figure 1]

[0023] With reference to [Fig. 1], it is a schematic diagram showing an apparatus for activating at least one sensor according to the present invention; [Figure 2] [Figure 2] is an enlarged, partially cutaway view of the device of Figure 1; [Figure 3]

[0023] Referring to [Fig. 3], it is a schematic diagram of a second embodiment of the starting device according to the present invention; [Figure 4]

[0023] Referring to [Fig. 4], it is a flowchart of a method for automatic power calibration of the wake-up signal of at least one sensor according to the present invention; [Figure 5]

[0023] Referring to FIG. 5, there is shown a flow chart of an alternative embodiment of the method of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0037] FIG. 1 is a highly schematic representation of an apparatus 1 for activating a sensor 9, more particularly a learning apparatus for a tire pressure monitoring system 3 of a motor vehicle 5 (wherein said apparatus 1 may also be referred to as a "valve activator" or "valve forcer") in this embodiment.

[0038] The automobile 5 has, on the one hand, tires 7 with built-in sensors 9 such as pressure sensors, and, on the other hand, an on-board computer 11 (also called an electronic control unit, commonly abbreviated as "ECU").

[0039] The device 1 comprises a unit 13, for example made of plastic, a display device 15, a keypad 17 and an antenna 19 for emitting sensor activation signals, as well as an OBD socket 21. Said OBD socket 21 is arranged in particular to allow the device 1 to be connected to the vehicle's on-board computer 11 using an OBD cable or a wireless (for example Bluetooth) dongle.

[0040] FIG. 2 is a schematic enlarged, partially cutaway view of the starting device 1 of FIG. 1, showing a part thereof.

[0041] The device 1 comprises: - at least one sensor activation module 31, such as means or a module for generating a sensor activation signal (continuous and / or modulated signal), said activation module 31 comprising in particular an antenna 19 making it possible to radiate said generated signal towards the sensor 9; a module 33 for receiving signals from the sensors, typically comprising a separate antenna integrated into the unit 13 and adapted to pick up signals in the frequency range of 300-500 MHz (the sensors emit signals in this frequency range after being activated by said activation module 31); - an electronic entity 35 configured to store and / or process the information carried by the signal emitted by said sensor 9 (and received via the receiving module 33); a module 37 for communicating with the on-board computer 11 of the motor vehicle, which transmits information from at least one of said sensors 9 (information received via signals from said sensors 9);

[0042] The communication module 37 is for example an OBD module comprising an OBD communication management circuit 38 and the aforementioned OBD socket 21. It should be noted that the management circuit 38 may also be integrated into the electronic entity 35. Furthermore, the device 1 also comprises a battery 41 arranged to power its different elements (and electronic components).

[0043] Furthermore, it is noted that the activation signal (emitted by the activation device) is a continuous or modulated electromagnetic signal emitted by the activation module 31. The activation signal has a frequency of, for example, 125 kHz.

[0044] As shown in Figures 1 and 2, the activation device 1 is a portable device (in particular a device that can be operated by hand by an operator), but such a device can also be in the form of a fixed or transportable device intended to be placed in a factory, in particular next to a production line, in a garage, or on the premises of a vehicle fleet manager, etc.

[0045] Unlike the device of FIG. 1, the activation device 1′ shown in FIG. 3 is intended to be placed at a fixed location, whereas the sensor to be activated is generally at a defined distance, for example on a production line 40 comprising a belt conveyor on which at least one tire P equipped with a sensor C1 is placed.

[0046] The activation device 1' can therefore comprise all the elements previously described for the activation device of FIG.

[0047] However, unlike the activation device 1 of Fig. 1, the activation device 1' intended for industrial applications generally does not comprise a screen, a keypad, or an OBD communication module etc. Programming and interaction with the device 1' can be performed using a third party electronic device connected to it, for example via a communication module 37' of the device 1'.

[0048] [Figure 3] is a highly schematic representation of a device 1' for activating a sensor 9 for an industrial environment, showing a part of it.

[0049] The activation device 1,1' is for example configured to emit an activation signal towards at least one sensor 9,C1, which sensor 9,C1 is optionally integrated into the tire 7,P.

[0050] When activated by an activation signal, the sensor 7, C1 returns one or more response signals.

[0051] The at least one sensor 7, C1, here a pressure sensor for an automotive pressure monitoring system, comprises at least one data transmitting / receiving module and an identification number.

[0052] Regardless of the application, it may be advantageous to calibrate the power of the activation signal emitted by the activation device 1, 1' in order to limit the operator's exposure to electromagnetic waves and to optimize the electrical consumption of the device 1, 1'.

[0053] For this purpose, the device 1 , 1 ′ is configured to execute a method 100 for automatically calibrating the transmission power of the activation signal of at least one sensor 9 .

[0054] The method 100, as particularly illustrated by FIG. 4, includes: - the maximum power P of the deactivation signal of said sensor max and the minimum power P of the activation signal of the sensor min Step S to determine det ; - Power P max ,P min When the difference δ between the maximum power P max and the minimum power P min Step S mem .

[0055] In this way, P min -P max When the difference δ≦δ0 is equal to max and minimum power P min The value of is stored in a memory, for example a random access memory or a read-only memory of the electronic entity 35. This allows the minimum power P min are used under nominal operating conditions of the starter 1, 1'.

[0056] The method 100 also includes a pre-initialization step S init During this step, the maximum power of the non-activation signal P max , the minimum power of the activation signal P min , and the maximum power P max and minimum power P min An initial value for the difference δ0 between

[0057] Maximum Power P max and minimum power P min The step of determining the power P max ,P min The process is stopped when the difference δ between the two reaches a value less than or equal to the value of the difference δ0.

[0058] It should be noted that the smaller the difference δ, the longer the method according to the invention will take. Furthermore, the closer the sensor for which the minimum activation power is determined is to other sensors, the smaller the value of the difference δ needs to be in order to avoid activating nearby sensors.

[0059] More specifically, the maximum power P max and minimum power P min Step S to determine det includes several sub-steps that can be repeated until the difference δ is less than or equal to δ0.

[0060] Parameter P min ,P max ,When the initial value of δ0 is set, the maximum power P max and minimum power P min The power P corresponding to the arithmetic mean of the values ​​of i a sensor activation signal S i is generated, i.e., where

[0061]

number

[0062] Start signal S iA predetermined time after the transmission of the response signal S from at least one sensor C (The activation signal S i The detection or non-detection of a response signal (a response signal emitted in response to the signal) is considered.

[0063] The response signal is transmitted, for example, at a predetermined time T R and the time T R is, for example, greater than 5 seconds, preferably between 5 and 10 seconds.

[0064] Then, the starter 1, 1' receives a response signal S from at least one sensor. C If reception of the power value P min There is a step S2 of updating the power P of the previously emitted activation signal. i The value of is then the new minimum power value P min and the parameter P min The value of the activation signal S i The value is corrected for the next transmission.

[0065] On the other hand, the activation device 1, 1' receives a response signal S from at least one sensor. C Reception of (predetermined time T R If it does not detect the power P of the previously emitted activation signal, i The value of is the maximum power P max (step S3), and the parameter P max The value of the activation signal S i The value is corrected for the next transmission.

[0066] Parameter P min ,P max is modified, in particular during step S2 or step S3, min or maximum power P max The difference δ between the values ​​of P is calculated. More specifically, the difference δ=P min -P max is.

[0067] Next, step S5 is performed in which the difference δ thus calculated is compared with a predetermined value δ0 for this difference (i.e., a target value for the difference). If the calculated value δ is greater than the predetermined value δ0, a new iteration of steps S1 and S2 or steps S1 and S3 is performed. In this way, a minimum power P is obtained depending on whether steps S2 or S3 were performed during the previous iteration. min or maximum power P max Taking into account the correction value of one of the power P i A new start signal S i is issued.

[0068] The power P max and P min The step of determining the activation signal S i Power P i is implemented by a dichotomous change of the activation signal S i Power P i Since there are iterations by changing min and maximum power P max According to the arithmetic mean of

[0069] More specifically, the operations performed in steps S1 to S5 described herein are then repeated until the calculated difference δ is equal to or less than a predetermined value δ. When this condition is met, the minimum power P min and maximum power P max The value of corresponds to the desired optimum value, and the step S mem are stored in memory during

[0070] In an alternative embodiment of the method of Fig. 4, particularly when there are several sensors, for example in the case of dual wheels, a calibration of the transmission power of the activation signal is carried out for each of the sensors, which are generally located at different spatial positions. This involves, in addition to the identifier, determining the maximum power P max and the minimum power P min This means that a value of δ, as well as a predetermined value δ0, is advantageously associated with each sensor.

[0071] Furthermore, each sensor has a specific identifier, and advantageously the sensor (and its identifier) ​​is associated with a spatial location (e.g., location n°1 of the nearest sensor, location n°2 of the second nearest sensor, etc.) The association of the sensor (and its identifier) ​​with a location is determined, for example, depending on the (received) power of a response signal emitted in response to receiving an activation signal.

[0072] Thus, unlike method 100, there is the reception of a set of response signals emitted by different sensors, each response signal carrying the identity of the sensor that emitted it in response to receiving an activation signal emitted by the activation device 1, 1′, and a maximum power P max and minimum power P min The value of is updated accordingly.

[0073] This means that for a given power P of the activation signal i for a predefined response time T R When the sensor does not emit a response signal within the max On the other hand, if a response signal is received, the minimum activation power P min This means that there is an update to the value of

[0074] There are iterations of the different steps of the method 100, and thus the maximum power P max and minimum power P min The set of values ​​of the power P max ,P min While the difference between δ and δ is not determined to be less than or equal to a predetermined value δ (for each of the sensors), the activation signal is transmitted.

[0075] Thus, for each sensor, depending on whether or not a signal (carrying an identifier or identification number) is received from the emitted sensor, an activation signal P i In (and successive repetitions of sending activation signals), successive decisions are made to activate or deactivate each sensor.

[0076] For a given sensor, the maximum power P maxand minimum power P min When the difference δ between max and minimum power P min until the set of differences δ between the two is determined to be equal to or less than a predetermined value δ0.

[0077] [Figure 5] is a flowchart of an alternative embodiment of the method of Figure 4, a portion of which is shown. The method 100' of Figure 5 has substantially the same steps as the method of Figure 4, which will not necessarily be described again or exhaustively except to identify differences or peculiarities. Furthermore, where steps are similar or analogous, the same reference numerals are used.

[0078] Thus, unlike method 100, method 100' of FIG. 5 does not include an initialization step S init After that, a step S of detecting the activated sensors is performed. id In fact, the method according to the invention involves detecting a plurality of sensors C m Since the sensors can be located at different distances from the initiator 1, 1', it is necessary to find an initiator signal whose power matches the nominal and standard operating conditions of the initiator.

[0079] To this end, a number of sensors for which the activation signal is to be calibrated are identified in advance.

[0080] In this way, the initialization step S init is followed by a step S6 of verifying the presence in memory of an identification number (or identifier) ​​Id associated with each of said sensors.

[0081] If the sensor identifier is not stored in memory, the power i A so-called identification activation signal is transmitted S7, for example with the maximum possible transmission power at which the activation device can emit a signal.

[0082] Then, at a predetermined time, for example, T R During this time, a step S8 is performed in which a response signal emitted by the sensor is received. The response signal carries the identification number (or identifier) ​​of the sensor, and a step S9 is performed in which the identification number (or identifier) ​​of each sensor that emitted a response signal to the identification activation signal is stored in memory.

[0083] and the maximum power P of the sensor's deactivation signal max and the minimum power P of the sensor activation signal min Step S to determine det will be carried out.

[0084] Unlike the method 100 in [Fig. i After sending the start signal with: - a response signal S from a set of sensors stored in memory c is received, the power P of the previously emitted activation signal i The value of is the new minimum power value P min and the parameter P minの The value is corrected for the next transmission of the activation signal Si (step S2); -From a set of sensors stored in memory (for a given time T R During the response signal S C If no signal is received, the power of the previously emitted activation signal P i The value of is the new maximum power value P max and the parameter P max The value of the start signal S i is modified for the next transmission (step S3).

[0085] Then, as before, the minimum power P min and maximum power P max The difference δ between these values ​​is calculated (S4) and compared with a predetermined value δ0 (S5).

[0086] If the calculated difference δ is greater than the predetermined value δ0, a new iteration of steps S1 and S2 or S1 and S3 is performed. i New launch signal S iis emitted, but with a minimum power P min or maximum power P max Consider the correction value of one of the following.

[0087] Otherwise, i.e., if the power difference δ is less than or equal to the predetermined value δ0, the determination of the transmission power is stopped and the maximum power P max and minimum power P min is stored in a memory, for example a random access memory or a read-only memory, of the electronic entity 35. This is especially true for the minimum power P min This is to ensure that the value is used under the nominal operating conditions of the starter 1, 1'.

[0088] It should be noted that in an alternative embodiment of the method 100', the identification numbers may be manually entered or manually sorted by a user after transmitting the identification signals and receiving the response signals.

[0089] In another alternative embodiment of the methods 100 and 100', not shown, the transmission power of the activation signal used during the nominal operating state of the activation device 1, 1' corresponds to a minimum power Pmin stored in memory, increased by a predefined percentage, for example 10%, to ensure activation of the sensor(s).

Claims

1. At least one sensor (C １ ) in particular for a tire pressure monitoring system (7) of a motor vehicle (5), wherein the power (Pi) of the activation signal (Si) of said pressure sensor (C １ ) has an identification number (Id) and comprises at least one data transmitting and receiving module; The method (100, 100') comprises: - the maximum transmission power P of the deactivation signal of the sensor ｍａｘ and the minimum transmission power P of the activation signal of the sensor ｍｉｎ determining (Sdet); and - said power P ｍａｘ and the power P ｍｉｎ The difference δ between ０ When the maximum transmission power P ｍａｘ and the minimum transmission power P ｍｉｎ and storing the result in a memory (Smem).

2. The maximum power P ｍａｘ and the minimum power P ｍｉｎ The determination step (Sdet) of the power P ｍａｘ and the power P ｍｉｎ The difference δ between ０ 2. The method (100, 100') of claim 1, characterized in that it is stopped when:

3. The power P ｍａｘ and the power P ｍｉｎ 3. The method (100, 100') according to claim 2, characterized in that the determination step (Sdet) is carried out by a dichotomous variation of the power (Pi) of the activation signal (Si).

4. The power P ｍａｘ and the power P ｍｉｎ The determination step (Sdet) of the power P ｉ The method (100, 100') according to any one of claims 1 to 3, characterized in that it is carried out by detecting or not detecting at least one response signal (Sc) from said at least one sensor according to said activation signal (Si) previously emitted by said sensor.

5. When a response signal (Sc) is received from said at least one sensor (C1), the power P of said activation signal (Si) that activated said sensor (C1) ｉ is the minimum power P ｍｉｎ 5. The method (100, 100') according to claim 4, characterized in that:

6. If no response signal (Sc) is received from the at least one sensor (C1), the power P of the emitted activation signal (Si) ｉ is the maximum power P ｍａｘ 6. The method (100, 100') according to claim 4 or 5, characterized in that:

7. There is a step (Sinit) of initializing the method, during which the maximum power P of the non-activation signal is ｍａｘ , the minimum power P of the activation signal (Si) ｍｉｎ , and the maximum power P ｍａｘ and the minimum power P ｍｉｎ The difference δ between ０ The method (100, 100') according to any one of claims 1 to 6, characterized in that the initial value of is predetermined.

8. The emitted activation signal (Si) is ｍａｘ and the minimum power P ｍｉｎ The power P corresponding to the arithmetic mean of ｉ The method (100, 100') according to any one of claims 1 to 7, characterized in that it comprises:

9. Method (100, 100') according to any one of claims 1 to 8, characterized in that a pre-identification of the sensor is performed by a step (S7) of transmitting an activation signal (Si) with a power Pi.

10. 10. A method (100, 100') according to claim 9, characterized in that it includes a step (S9) of storing in a memory the identification number (Id) of each of the sensors which emitted a signal in response to the identification activation signal.

11. Each sensor (C １ 11. The method (100, 100') according to any one of claims 1 to 10, characterized in that there is a manual pre-storing in memory of said identification number (Id) of said device.

12. A device (1; 1') for activating at least one sensor, in particular a pressure sensor for a tire pressure monitoring system (7) of a motor vehicle (5), The device comprises: - at least one sensor activation module (31); - a module (33) for receiving signals from said sensors; an electronic entity (35) configured to store and / or process the information conveyed by the signal transmitted by said sensor (9); and a module (37; 37') for communicating with a remote electronic entity, such as the on-board computer (11) of the motor vehicle (5), in order to transmit the information carried by said signals received; The device, on the other hand, has a maximum transmission power P of the deactivation signal of the at least one sensor. ｍａｘ and a minimum transmission power P of a signal that causes activation of the at least one sensor. ｍｉｎ On the other hand, the power P ｍａｘ and the power P ｍｉｎ The difference δ between ０ When the maximum power P ｍａｘ and the minimum power P ｍｉｎ The device is configured to stop the step of determining (Sdet) whether:

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