Bluetooth-based tire pressure sensor positioning method

Abstract

The invention relates to a Bluetooth-based tire pressure sensor positioning method. The tire pressure sensor positioning method comprises the steps that S1, Bluetooth connection is established between a vehicle ECU and a tire pressure sensor, and clock synchronization is established on the vehicle ECU and the tire pressure sensor; s2, the tire pressure sensor periodically sends a positioning data packet to the vehicle ECU, the positioning data packet at least comprises backspacing time, and the backspacing time is used for representing the moment when the tire pressure sensor reaches the reference point; s3, the vehicle ECU calculates the corresponding moment when the vehicle ECU side reaches the reference point based on the backspacing time; s4, the vehicle ECU carries out deviation degree statistics on the obtained ABS information based on the corresponding moment, and a tire pressure sensor is positioned according to a statistical result; and S5, if the vehicle ECU positions the tire pressure sensor, the vehicle ECU instructs the tire pressure sensor to stop sending the positioning data packet. The tire pressure sensor can be effectively positioned, and the service life of the tire pressure sensor can be prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle tire positioning, and in particular to a tire pressure sensor positioning method based on Bluetooth. Background Art

[0002] Tire Pressure Monitoring System (TPMS) plays a vital role in vehicle safety. Battery-powered tire pressure sensor modules installed inside the tire can continuously monitor key parameters such as tire pressure, temperature, and acceleration. These sensors then transmit the collected detailed information to the vehicle body ECU via radio frequency signals, providing important data support for the safe operation of the vehicle.

[0003] In order to accurately evaluate the status of each tire, each tire pressure sensor is equipped with a unique ID code. This requires the vehicle to be matched and set up to match the tire position with the sensor's ID code one by one, so that the vehicle can know exactly which module is located in which tire position, such as the left front, right front, and other specific positions.

[0004] Traditional tire pressure sensors usually use 315M or 433M transmitters to achieve data transmission. However, this method has certain limitations. Data can only be sent from the tire pressure sensor to the vehicle body ECU in one direction. In addition, the sensor will enter the automatic positioning mode every time you drive and execute the automatic positioning algorithm a fixed number of times. This frequent automatic positioning operation has a great impact on battery power consumption, thereby reducing the service life of the product.

[0005] The traditional matching methods are mainly the following:

[0006] Manual matching: This method requires professionals to use professional tools to complete the matching work. It is professionally difficult and not only time-consuming and labor-intensive, but also requires a high level of technical skills from the operator.

[0007] Automatic positioning is achieved through the RSSI signal strength of the radio frequency signal: However, the RSSI signal is greatly affected by environmental factors, such as building obstruction, electromagnetic interference, etc., which leads to poor positioning effect and difficulty in accurately determining the tire position.

[0008] Automatic positioning is achieved by combining ABS data: This method has certain advantages, such as high positioning accuracy, low environmental impact, and no need for human intervention. However, it has strict requirements on the timing of the sensor's RF transmission, which also leads to the problem of high power consumption.

[0009] In recent years, tire pressure sensors using Bluetooth technology have gradually been applied to the market. However, the current automatic positioning solution can only identify the location information through RSSI, which makes the positioning accuracy poor and prone to positioning errors, affecting the user's trust in the technology and the user experience. Summary of the invention

[0010] In view of the above problems in the prior art, the present invention proposes a tire pressure sensor positioning method based on Bluetooth, which can achieve effective positioning of the tire pressure sensor and extend the service life of the tire pressure sensor.

[0011] Specifically, the present invention proposes a tire pressure sensor positioning method based on Bluetooth, comprising the steps of:

[0012] S1, the vehicle ECU and the tire pressure sensor establish a Bluetooth connection, and create clock synchronization between the vehicle ECU and the tire pressure sensor;

[0013] S2, the tire pressure sensor periodically sends a positioning data packet to the vehicle ECU, the positioning data packet at least including a backoff time, the backoff time is used to represent the time when the tire pressure sensor reaches the reference point;

[0014] S3, the vehicle ECU calculates the corresponding time when the vehicle ECU side reaches the reference point based on the fallback time;

[0015] S4, the vehicle ECU performs deviation statistics on the acquired ABS information based on the corresponding time, and locates the tire pressure sensor according to the statistical result;

[0016] S5, if the vehicle ECU locates the tire pressure sensor, the vehicle ECU instructs the tire pressure sensor to stop sending the positioning data packet.

[0017] According to one embodiment of the present invention, in step S1, creating clock synchronization includes the steps of:

[0018] S11, creating a counter with the same time step on the vehicle ECU and the tire pressure sensor;

[0019] S12, the vehicle ECU obtains the count value of the counter of the tire pressure sensor;

[0020] S13, the vehicle ECU calculates a synchronization time difference between the vehicle ECU and the tire pressure sensor according to the acquired count value of the counter of the tire pressure sensor.

[0021] According to an embodiment of the present invention, the time step is less than or equal to 1 ms.

[0022] According to one embodiment of the present invention, in step S2, after receiving the vehicle ECU start positioning instruction, the tire pressure sensor performs the following steps:

[0023] Executing a self-positioning algorithm, the self-positioning algorithm includes collecting the centripetal acceleration of the wheel, the characteristic curve of the centripetal acceleration is a sine curve, and selecting a specific angle of the centripetal acceleration as the reference point;

[0024] Complete the self-positioning algorithm and generate the positioning data packet including the backoff time;

[0025] The positioning data packet is sent to the vehicle ECU.

[0026] According to an embodiment of the present invention, the highest point, the lowest point or the zero-crossing point of the sine curve of the centripetal acceleration is selected as the reference point.

[0027] According to one embodiment of the present invention, assuming that the time when the tire pressure sensor completes the positioning algorithm is T2, the time when the positioning data packet is sent is T3, and the time difference between the time when the centripetal acceleration reaches the reference point and the time T2 is T4, then the back-off time is T3-T2+T4.

[0028] According to an embodiment of the present invention, in step S3, assuming that the synchronization time difference between the vehicle ECU and the tire pressure sensor is ΔT, the corresponding time between the vehicle ECU side and the reference point is T3-T2+T4-ΔT.

[0029] According to an embodiment of the present invention, in step S4, the vehicle ECU periodically receives the ABS information, the ABS information is obtained through an ABS sensor disposed on a wheel, and the ABS information includes position information of the wheel.

[0030] According to an embodiment of the present invention, the ABS information includes the number of teeth of the ring gear on the wheel recorded by the ABS sensor, and the vehicle ECU determines the relative position of the wheel with respect to the ABS sensor according to the number of teeth.

[0031] According to one embodiment of the present invention, in step S2, the positioning data packet further includes the ID of the tire pressure sensor;

[0032] Positioning the tire pressure sensor in step S4 refers to associating the ID of the tire pressure sensor with the wheel position information included in the ABS information in the statistical result.

[0033] The present invention provides a tire pressure sensor positioning method based on Bluetooth, which creates clock synchronization on a vehicle ECU and a tire pressure sensor. According to the back-off time contained in a positioning data packet, the vehicle ECU calculates the corresponding time when the vehicle ECU side reaches a reference point, and performs deviation statistics based on the ABS information obtained at the corresponding time. According to the statistical result, the tire pressure sensor is positioned and the tire pressure sensor is instructed to stop sending the positioning data packet, so that the tire pressure sensor can save power and extend its service life.

[0034] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this application. The accompanying drawings illustrate embodiments of the present invention and together with the description serve to explain the principle of the present invention.

[0036] In the attached figure:

[0037] Figure 1 A flowchart of a tire pressure sensor positioning method according to an embodiment of the present invention is shown.

[0038] Figure 2 A schematic diagram showing data interaction between a vehicle ECU and a tire pressure sensor after Bluetooth connection according to an embodiment of the present invention.

[0039] Figure 3 A schematic diagram showing time synchronization between a vehicle ECU and a tire pressure sensor according to an embodiment of the present invention is shown.

[0040] Figure 4 A schematic diagram showing the centripetal acceleration acquired by a tire pressure sensor according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0045] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0046] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0047] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0048] First, the design idea of ​​a positioning method provided by the present invention is briefly described. Conventionally, taking a small car as an example, it includes four tires, namely the front left (FL), the front right (FR), the rear right (RR), and the rear left (RL). After the tire condition monitoring system is installed on each tire, it is necessary to determine the installation position of the tire pressure detection device. During the tire driving process, a wireless signal and a wired signal are obtained at the same reference point (same rotation angle) of any rotation cycle. The wireless signal is associated with the reference point of the acceleration signal, and the wired signal includes the ABS signal of the gear pulse sensor of the tire and the tire position (for example, FL) where the known gear pulse sensor is located. The actual number of teeth information corresponding to the reference point is calculated according to the wired signal and the wireless signal to generate a queue of a set of tooth number information. For example, the wireless signal of a tire and the wired signal of the front left tire (FL), the wired signal of the front right tire (FR), the wired signal of the rear right tire (RR), and the wired signal of the rear left tire (RL) can form a queue of four sets of tooth number information. According to data statistics, the group of teeth with the smallest deviation, assuming that the wired signal of the front left tire (FL) has the smallest deviation, the corresponding tire condition monitoring system is determined to be installed on the front left tire (FL). By analogy, the actual position of each tire condition monitoring system can be confirmed, thereby realizing the autonomous learning of the tire position of the tire condition monitoring system.

[0049] Figure 1 The flowchart of a tire pressure sensor positioning method according to an embodiment of the present invention is shown. As shown in the figure, a tire pressure sensor positioning method based on Bluetooth provided by the present invention comprises the following steps:

[0050] S1, the vehicle ECU and the tire pressure sensor establish a Bluetooth connection, and create clock synchronization on the vehicle ECU and the tire pressure sensor. Figure 2 A schematic diagram of data interaction between a vehicle ECU and a tire pressure sensor after Bluetooth connection is shown in an embodiment of the present invention. As shown in the figure, the vehicle ECU and the tire pressure sensor establish a Bluetooth connection to achieve two-way data transmission. After the Bluetooth connection is established, the communication between the two is based on the traditional CS architecture, that is, the vehicle ECU acts as the client and the tire pressure sensor acts as the server. In order to reduce power consumption, the data transmission of Bluetooth devices after connection is interacted in the connection event. In order to ensure the accuracy and timeliness of data transmission, it is necessary to create clock synchronization on the vehicle ECU and the tire pressure sensor.

[0051] S2, the tire pressure sensor periodically sends a positioning data packet to the vehicle ECU, the positioning data packet at least includes a backoff time, and the backoff time is used to represent the time when the tire pressure sensor reaches the reference point;

[0052] S3, the vehicle ECU calculates the corresponding time when the vehicle ECU side reaches the reference point based on the backoff time. When the vehicle ECU receives the positioning data packet sent by the tire pressure sensor, the vehicle ECU can infer the corresponding time when the vehicle ECU side reaches the reference point by parsing the backoff time in the data packet.

[0053] S4, the vehicle ECU performs deviation statistics on the acquired ABS information based on the corresponding time, and locates the tire pressure sensor according to the statistical results. As mentioned above, the tire position information contained in the ABS information with the smallest deviation is associated with the tire pressure sensor to complete the positioning of the tire pressure sensor.

[0054] S5, if the vehicle ECU locates the tire pressure sensor, the vehicle ECU instructs the tire pressure sensor to stop sending positioning data packets. Stopping the sending of positioning data packets can significantly reduce the energy consumption of the tire pressure sensor, extend its battery life, and reduce the frequency and cost of battery replacement.

[0055] In some examples, in step S1, creating clock synchronization includes the steps of:

[0056] S11, creates counters with the same time step on the vehicle ECU and tire pressure sensor, laying the foundation for subsequent clock synchronization operations.

[0057] S12, the vehicle ECU obtains the count value of the tire pressure sensor counter. Since the vehicle ECU and the tire pressure sensor may have different environments and internal processing speeds during actual operation, the count values ​​may not be completely consistent even though the time steps of the counters are the same.

[0058] S13, the vehicle ECU calculates the synchronization time difference between the vehicle ECU and the tire pressure sensor based on the count value of the counter of the tire pressure sensor. Specifically, the vehicle ECU will use a specific algorithm to calculate the synchronization time difference between the vehicle ECU and the tire pressure sensor based on the count value obtained. For example, by comparing the current count values ​​of the two counters, according to the conversion relationship of the time step, the time deviation between them is calculated in milliseconds or microseconds. The synchronization time difference is used to subsequently calculate the corresponding time when the vehicle ECU side reaches the reference point.

[0059] Preferably, the time step is less than or equal to 1ms. In the vehicle's tire pressure monitoring system, the requirements for time accuracy are relatively high. When the time step is less than or equal to 1ms, it means that the vehicle ECU and tire pressure sensor can record the passage of time at a finer time scale. For example, in the process of monitoring tire pressure changes or locating tire pressure sensors, many subtle state changes may occur in a very short period of time. A smaller time step can capture these instantaneous changes more accurately, which helps to obtain relevant data more timely and accurately and conduct subsequent analysis and processing.

[0060] In some examples, in step S2, after receiving the vehicle ECU start positioning instruction, the tire pressure sensor performs the following steps:

[0061] A self-positioning algorithm is executed. The self-positioning algorithm includes collecting the centripetal acceleration of the wheel. The characteristic curve of the centripetal acceleration is a sine curve. A specific angle of the centripetal acceleration is selected as a reference point. Figure 3 A schematic diagram of the centripetal acceleration obtained by the tire pressure sensor of an embodiment of the present invention is shown. As shown in the figure, it should be noted that during the driving of the vehicle, the rotation of the wheel will generate centripetal acceleration, and the magnitude and direction of this acceleration will continue to change with the rotation of the wheel. The centripetal acceleration is affected by the acceleration of gravity and changes in a sinusoidal wave. For example, when the wheel rotates one circle, the centripetal acceleration will gradually decrease from the maximum value to zero, and then increase from zero to the maximum value, and so on. In order to accurately determine the position and state of the wheel, it is necessary to select a specific angle as a reference point. This reference point can be a specific position on the centripetal acceleration curve, such as the peak value, zero point or other point with obvious characteristics of the sine curve. By selecting this reference point, an accurate benchmark can be provided for subsequent positioning calculations.

[0062] After the self-positioning algorithm is completed, a positioning data packet containing the fallback time is generated. In addition to the fallback time, the positioning data packet may also contain other information related to the tire status and position, such as tire pressure, temperature, acceleration and other parameters.

[0063] Send positioning data packets to the vehicle ECU.

[0064] Preferably, the highest point, the lowest point or the zero-crossing point of the sine curve of the centripetal acceleration is selected as the reference point.

[0065] Figure 4 A schematic diagram of time synchronization between a vehicle ECU and a tire pressure sensor according to an embodiment of the present invention is shown. As shown in the figure, in this example, clock synchronization is first established on the vehicle ECU and the tire pressure sensor. At point A in the figure, the counter value of the vehicle ECU is T0, and the counter value of the tire pressure sensor is T1.

[0066] B is the reference point, and the moment when the tire pressure sensor completes the positioning algorithm at point C is T2. Based on the Bluetooth communication mechanism, the data will send the positioning data packet in the next connection event, that is, point D. The moment when the positioning data packet is sent is T3. The positioning algorithm can obtain the time difference from point C to point B as T4, and the fallback time refers to the fallback from point D to point B, which is T3-T2+T4.

[0067] As mentioned above, at point A, the counter value of the vehicle ECU is T0, and the counter value of the tire pressure sensor is T1, then the synchronization time difference between the vehicle ECU and the tire pressure sensor is ΔT, ΔT = (T2-T1) * time step. In step S3, the vehicle ECU calculates the corresponding time when the vehicle ECU side reaches the reference point based on the fallback time as T3-T2+T4-ΔT.

[0068] In some examples, in step S4 , the vehicle ECU periodically receives ABS information, where the ABS information is obtained through ABS sensors disposed on wheels, and the ABS information includes position information of the wheels.

[0069] In some examples, ABS information includes the number of teeth on the ring gear on the wheel recorded by the ABS sensor, and the vehicle ECU determines the relative position of the wheel relative to the ABS sensor based on the number of teeth. The ring gear equipped on the wheel will rotate synchronously with the rotation of the wheel, and the ABS sensor installed near the wheel can accurately record the number of teeth on the ring gear. Whenever the teeth on the ring gear pass through the ABS sensor, the sensor will capture the corresponding signal changes and count the number of teeth passing through. For example, the ring gear has 96 teeth, and the number of teeth recorded by the ABS sensor is a regular variable of 0-95-0-95. The vehicle ECU will obtain the ABS information including the number of teeth on the ring gear, and then determine the relative position of the wheel relative to the ABS sensor based on the number of teeth.

[0070] In some examples, in step S2, the positioning data packet also includes an ID of the tire pressure sensor;

[0071] Positioning the tire pressure sensor in step S4 means associating the ID of the tire pressure sensor with the wheel position information contained in the ABS information in the statistical result. Specifically, taking a car as an example, after receiving the first positioning data packet of a tire pressure sensor, the vehicle ECU calculates the corresponding time when the vehicle ECU side reaches the reference point according to the parsed backoff time and synchronization time difference, and obtains the ABS information of the four wheels at the corresponding time. Repeat this step, obtain the ABS information queue of the four wheels according to n packets of positioning data packets, and perform variance statistics on the ABS information queue. Referring to Table 1, according to the variance statistics, the ABS information of the front left tire (FL) is relatively convergent, that is, the corresponding deviation is the smallest, and the corresponding tire pressure sensor is determined to be installed on the front left tire (FL). The vehicle ECU can send a positioning end instruction to the tire pressure sensor, and the tire pressure sensor will no longer execute the self-determined positioning algorithm during this driving process, which can save its battery power consumption. Through the above method, the actual position of each tire pressure sensor can be confirmed to achieve automatic positioning.

[0072] Table 1 Variance statistics of ABS information queue

[0073]

[0074]

[0075] The present invention provides a tire pressure sensor positioning method based on Bluetooth, which uses Bluetooth signals as radio frequency transmission signals. Compared with traditional 315M and 433M tire pressure sensors, Bluetooth technology greatly improves the integration of tire pressure sensors and smart vehicles, and realizes two-way transmission of data. In other words, the tire pressure sensor can send information such as tire pressure and temperature to the vehicle ECU, and the vehicle ECU can also send instructions to the tire pressure sensor or perform operations such as parameter setting. Furthermore, by synchronizing the clock, the vehicle ECU can find the corresponding moment of the reference point according to the fallback time, and then obtain the ABS information at the corresponding moment, perform statistics on the deviation degree of the ABS information, realize the positioning of the tire pressure sensor, and instruct the tire pressure sensor to stop sending positioning data packets, so that the tire pressure sensor can save power and extend its service life.

[0076] It will be apparent to those skilled in the art that various modifications and variations may be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention covers modifications and variations of the present invention that fall within the scope of the appended claims and their equivalent technical solutions.

Claims

1. A tire pressure sensor positioning method based on Bluetooth, comprising the steps of: S1, the vehicle ECU and the tire pressure sensor establish a Bluetooth connection, and create clock synchronization between the vehicle ECU and the tire pressure sensor; S2, the tire pressure sensor periodically sends a positioning data packet to the vehicle ECU, the positioning data packet at least including a backoff time, the backoff time is used to represent the time when the tire pressure sensor reaches the reference point; S3, the vehicle ECU calculates the corresponding time when the vehicle ECU side reaches the reference point based on the fallback time; S4, the vehicle ECU performs deviation statistics on the acquired ABS information based on the corresponding time, and locates the tire pressure sensor according to the statistical result; S5, if the vehicle ECU locates the tire pressure sensor, the vehicle ECU instructs the tire pressure sensor to stop sending the positioning data packet.

2. The tire pressure sensor positioning method according to claim 1, characterized in that: In step S1, creating clock synchronization includes the steps of: S11, creating a counter with the same time step on the vehicle ECU and the tire pressure sensor; S12, the vehicle ECU obtains the count value of the counter of the tire pressure sensor; S13, the vehicle ECU calculates a synchronization time difference between the vehicle ECU and the tire pressure sensor according to the acquired count value of the counter of the tire pressure sensor.

3. The tire pressure sensor positioning method according to claim 2, characterized in that: The time step is less than or equal to 1 ms.

4. The tire pressure sensor positioning method according to claim 1, characterized in that: In step S2, after receiving the vehicle ECU start positioning instruction, the tire pressure sensor executes the following steps: Executing a self-positioning algorithm, the self-positioning algorithm includes collecting the centripetal acceleration of the wheel, the characteristic curve of the centripetal acceleration is a sine curve, and selecting a specific angle of the centripetal acceleration as the reference point; Complete the self-positioning algorithm and generate the positioning data packet including the backoff time; The positioning data packet is sent to the vehicle ECU.

5. The tire pressure sensor positioning method according to claim 4, characterized in that: The highest point, the lowest point or the zero-crossing point of the sine curve of the centripetal acceleration is selected as the reference point.

6. The tire pressure sensor positioning method according to claim 4, characterized in that: Assume that the time when the tire pressure sensor completes the positioning algorithm is T2, the time when the positioning data packet is sent is T3, and the time difference between the time when the centripetal acceleration reaches the reference point and the time T2 is T4, then the back-off time is T3-T2+T4.

7. The tire pressure sensor positioning method according to claim 6, characterized in that: In step S3, assuming that the synchronization time difference between the vehicle ECU and the tire pressure sensor is ΔT, the corresponding time between the vehicle ECU side and the reference point is T3-T2+T4-ΔT.

8. The tire pressure sensor positioning method according to claim 1, characterized in that: In step S4, the vehicle ECU periodically receives the ABS information, where the ABS information is obtained through an ABS sensor disposed on a wheel, and the ABS information includes position information of the wheel.

9. The tire pressure sensor positioning method according to claim 8, characterized in that: The ABS information includes the number of teeth of the ring gear on the wheel recorded by the ABS sensor, and the vehicle ECU determines the relative position of the wheel with respect to the ABS sensor according to the number of teeth.

10. The tire pressure sensor positioning method according to claim 8, characterized in that: In step S2, the positioning data packet also includes the ID of the tire pressure sensor; Positioning the tire pressure sensor in step S4 refers to associating the ID of the tire pressure sensor with the wheel position information included in the ABS information in the statistical result.

Images