Tire pressure monitoring system, positioning method, tire pressure electronic control unit, and vehicle

Abstract

The tire pressure monitoring system, the positioning method, the tire pressure electronic control unit and the vehicle in the embodiments of the present disclosure, the tire pressure electronic control unit responds to entering the automatic positioning mode, sends an automatic positioning instruction to each tire pressure sensor through a Bluetooth communication mode to make the tire pressure sensor enter the automatic positioning mode to send acceleration data to the tire pressure electronic control unit through the Bluetooth communication mode; receives and acquires the acceleration data and acquires the tooth number coding data of the wheel speed sensor; based on the consistency feature matching of the acceleration data and the tooth number coding data when the tire pressure sensor reaches the reference position, positions each tire where the tire pressure sensor is located; sends a stop positioning instruction to the tire pressure sensor that has successfully positioned through the Bluetooth communication mode. The tire pressure electronic control unit realizes the start and stop of the automatic positioning of the tire pressure sensor and the transmission of the tire state data through the Bluetooth bidirectional communication, and takes into account the power consumption and transmission efficiency of the tire pressure sensor.

Description

Technical Field

[0001] This disclosure relates to the field of tire monitoring technology, and in particular to tire pressure monitoring systems, positioning methods, tire pressure electronic control units, and vehicles. Background Technology

[0002] Tire Pressure Monitoring Systems (TPMS) are increasingly being integrated into automotive electronic systems. TPMS requires information on the pressure of each tire individually; therefore, automatic tire positioning during vehicle movement is essential for real-time tire pressure monitoring. This is especially important after tires have been replaced, as TPMS needs to automatically identify and locate the tire's position.

[0003] TPMS typically includes tire pressure sensors and a tire pressure electronic control unit (ECU). Tire pressure sensors are usually installed in individual tires to measure tire pressure, temperature, acceleration, and other tire condition data, as well as process this data for transmission via a wireless transmitter. The ECU is usually installed in the vehicle body, receives tire condition data via a wireless receiver, processes it, displays it, and issues appropriate alarms.

[0004] However, since tire pressure sensors are battery-powered, they need to be replaced once the battery is depleted. Therefore, how to save power consumption of the tire pressure sensors while still meeting the communication efficiency requirements of increasingly larger tire status data transmission volumes is a key challenge. For example, after installing a tire condition monitoring system (TVM), the installation location of the tire pressure monitoring device is first determined; this process of identifying the tire pressure sensor location is usually called "tire position learning for the TVM." Tire position learning for TVMs is divided into passive learning and active learning. Passive learning involves using specialized diagnostic tools, while active learning utilizes the existing devices on the vehicle without the need for additional auxiliary equipment. Compared to passive learning, which requires professionals to learn the ID using specialized diagnostic tools, active learning saves installation time and can autonomously learn the tire position without the need for professional after-sales personnel or specialized diagnostic equipment.

[0005] One difficult problem to handle during automatic positioning is managing sensor power consumption. According to national standards, sensor fault alarms must be triggered within 10 minutes of vehicle operation when a fault occurs. Therefore, the common practice is to execute the automatic positioning algorithm every 16 seconds within 10 minutes of the sensor's automatic positioning mode. During these 10 minutes, the tire pressure sensor frequently calls the algorithm and sends data, significantly impacting battery life. Automatic positioning needs to comprehensively consider positioning results under different road conditions and vehicle speeds.

[0006] 1. In urban road conditions, with a vehicle speed of less than 60km / h, the positioning time is approximately 3 minutes.

[0007] 2. In suburban road conditions, with a vehicle speed of less than 80km / h, the positioning time is approximately 3 minutes.

[0008] 3. On highways, with a speed greater than 100km / h, the positioning time is approximately 5 minutes.

[0009] 4. On bumpy roads, at a speed of 40km / h, the positioning time is approximately 5-8 minutes.

[0010] 5. On a collapsed road surface, at a speed of 35 km / h, the positioning time is approximately 8 minutes.

[0011] The above information shows that the positioning time only lasts about 8 minutes on bumpy or collapsed road surfaces. In normal urban and highway driving, positioning usually takes only 3 minutes. However, previous sensors, designed to be compatible with all situations, had a longer automatic positioning mode duration. This could cause the tire pressure sensor to perform unnecessary data collection and processing in the remaining time after positioning is complete, resulting in unnecessary power consumption.

[0012] Another problem is that current TPMS still uses a low operating frequency (such as 315 or 434MHz for uplink and 125KHz for downlink) for communication between tire pressure sensors and tire pressure electronic control units. This results in poor reliability and low transmission efficiency, making it difficult to meet the functional requirements of the rapidly developing intelligent driving system.

[0013] Therefore, how to solve the power consumption and signal transmission problems in the TPMS tire positioning process has become a technical problem that the industry urgently needs to solve. Summary of the Invention

[0014] In view of the shortcomings of the prior art described above, the purpose of this disclosure is to provide a tire pressure monitoring system, a positioning method, a tire pressure electronic control unit, and a vehicle to solve the problems in the related art.

[0015] This disclosure provides a tire pressure monitoring system for a vehicle. The vehicle's anti-lock braking system (ABS) has gears that rotate with each tire as it rolls. The vehicle is fixedly equipped with wheel speed sensors for detecting the gears corresponding to each tire and outputting tooth count encoded data. The tire condition monitoring system includes: a plurality of tire pressure sensors, each fixedly mounted on one of the tires; each tire pressure sensor includes at least two-axis acceleration sensors that rotate with the tire to output periodic acceleration data related to the rotation angle; each tire pressure sensor includes a first Bluetooth communication module; and a tire pressure electronic control unit, located in the vehicle, includes a second Bluetooth communication module for... In response to entering the automatic positioning mode, an automatic positioning command is sent to each tire pressure sensor via Bluetooth communication between the second Bluetooth communication module and the first Bluetooth communication module, causing the tire pressure sensor to enter the automatic positioning mode and send acceleration data to the tire pressure electronic control unit via Bluetooth communication. The tire pressure electronic control unit obtains acceleration data and tooth count encoding data within a preset time period from the automatic positioning command. Based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensor, the tire where each tire pressure sensor is located is located. A stop positioning command is sent to the successfully positioned tire pressure sensor via Bluetooth communication.

[0016] In an embodiment of the first aspect, each of the tire pressure sensors is configured to send a termination positioning command along with tire status data in response to a preset time period or after sending a number of positioning data signals corresponding to the preset time period without successful positioning; the tire pressure electronic control unit is configured to determine whether the positioning result is successful in response to the termination positioning command; if successful, it sends the stop positioning command to the tire pressure sensor that was determined to be successfully positioned; if unsuccessful, it uses the previous positioning result.

[0017] In an embodiment of the first aspect, the step of locating the tire where each tire pressure sensor is located based on the consistency feature matching of the acceleration data and the tooth count encoding data at the reference position of the tire pressure sensor includes: determining the index duration of the tooth count encoding data based on the time interval between the tire pressure sensor moving from an arbitrarily selected reference position to the position where the acceleration data is emitted in the rotation path; obtaining a set of reference values ​​for each tooth count encoding data at the reference position based on the backtracking of the index duration; and determining the tire corresponding to the set of tooth count encoding data reference values ​​with the best convergence at the reference position based on the convergence of the set of tooth count encoding data reference values ​​for each tire's gear.

[0018] In an embodiment of the first aspect, the reference position is any position on the rotation path of the tire pressure sensor.

[0019] In an embodiment of the first aspect, in the automatic positioning mode, the tire pressure sensor sends a preset number of positioning data signals within a preset time period, and the time interval between the sending actions of each positioning data signal is randomly set; and / or, each automatic positioning instruction includes multiple data frames, and each data frame contains acceleration data that can determine the reference position.

[0020] In the first aspect of the embodiment, the tire pressure sensor is configured to enter an operating mode in response to detecting that the vehicle speed has reached a first preset vehicle speed threshold; in the operating mode, the tire pressure sensor establishes a Bluetooth communication mode with a second Bluetooth communication module through a first Bluetooth communication module to send tire status data; the tire pressure electronic control unit is configured to enter the automatic positioning mode in response to detecting that the vehicle speed has reached a second preset vehicle speed threshold greater than the first preset vehicle speed threshold, and establishes a Bluetooth communication mode with the first Bluetooth communication module through the second Bluetooth communication module to send an automatic positioning command to the tire pressure sensor.

[0021] In an embodiment of the first aspect, the tire pressure sensor corresponding to each tire is coaxially arranged with the gear; and / or, the tire pressure electronic control unit obtains the tooth count encoding data from the vehicle communication bus.

[0022] A second aspect of this disclosure provides a tire positioning method applied to a tire pressure electronic control unit in a vehicle; each tire of the vehicle is fixedly equipped with a wheel speed sensor and a tire pressure sensor; the method includes: in response to entering an automatic positioning mode, sending an automatic positioning command to each of the tire pressure sensors via Bluetooth communication to cause the tire pressure sensors to enter an automatic positioning mode and send acceleration data to the tire pressure electronic control unit via Bluetooth communication; receiving and acquiring the acceleration data, and acquiring the tooth count encoding data of the wheel speed sensors; based on the consistency feature matching of the acceleration data and the tooth count encoding data at the reference position of the tire pressure sensors, positioning the tire where each tire pressure sensor is located; and sending a stop positioning command to the successfully positioned tire pressure sensors via Bluetooth communication.

[0023] A third aspect of this disclosure provides a tire pressure electronic control unit, comprising: a processor and a memory; the memory storing program instructions; and the processor for executing the program instructions to perform the tire alignment method as described in the second aspect.

[0024] A fourth aspect of this disclosure provides a vehicle comprising: a plurality of tires equipped with wheel speed sensors; and a tire pressure monitoring system as described in any of the first aspects.

[0025] As described above, the tire pressure monitoring system, positioning method, tire pressure electronic control unit, and vehicle in this embodiment of the present disclosure, in response to entering an automatic positioning mode, send an automatic positioning command to each of the tire pressure sensors via Bluetooth communication to cause the tire pressure sensors to enter the automatic positioning mode and send acceleration data to the tire pressure electronic control unit via Bluetooth communication; receive and acquire the acceleration data, and acquire the tooth count encoding data of the wheel speed sensors; based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensors, locate the tire where each tire pressure sensor is located; and send a stop positioning command to the successfully positioned tire pressure sensors via Bluetooth communication. The tire pressure electronic control unit realizes the start and stop of the automatic positioning of the tire pressure sensors and the transmission of tire status data through bidirectional Bluetooth communication, taking into account the power consumption and transmission efficiency of the tire pressure sensors. Attached Figure Description

[0026] Figure 1 This illustration shows a scenario where the tire pressure monitoring system is applied to a vehicle according to an embodiment of this disclosure.

[0027] Figure 2 A schematic diagram of the circuit structure of the tire pressure sensor in an embodiment of this disclosure is shown.

[0028] Figure 3 A schematic diagram of gears in an ABS system according to an embodiment of the present disclosure is shown.

[0029] Figure 4 This illustration shows a schematic diagram of the characteristic curves showing the synchronization between the angle signal and the tooth count encoding data signal corresponding to each tire in this embodiment of the present disclosure.

[0030] Figure 5 Display based on Figure 4 A schematic diagram showing how a reference position is selected in the characteristic curve of the angle signal to obtain the corresponding set of tooth number encoding values.

[0031] Figure 6 An example graph showing the curve relationship between ABS code values ​​and ABS variables in embodiments of this disclosure is provided.

[0032] Figure 7 A flowchart illustrating the tire positioning method in an embodiment of this disclosure is shown.

[0033] Figure 8 A schematic diagram of the circuit structure of the tire pressure electronic control unit in an embodiment of this disclosure is shown. Detailed Implementation

[0034] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the information disclosed herein. This disclosure can also be implemented or applied through other different specific embodiments, and various details in this disclosure can be modified or changed according to different viewpoints and application modules without departing from the spirit of this disclosure. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this disclosure can be combined with each other.

[0035] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, so that those skilled in the art to which this disclosure pertains can readily implement it. This disclosure may be embodied in many different forms and is not limited to the embodiments described herein.

[0036] In this disclosure, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic represented in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. Furthermore, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in any one or a group of embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples represented in this disclosure, as well as the features of those different embodiments or examples.

[0037] Furthermore, the terms "first" and "second" are used for illustrative purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the representation of this disclosure, "a set" means two or more, unless otherwise explicitly specified.

[0038] For the purpose of clarity, devices unrelated to the description are omitted, and the same or similar components throughout the specification are given the same reference numerals.

[0039] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Furthermore, when it is said that a device "comprises" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather implies that other constituent elements may be included.

[0040] While the terms first, second, etc., are used in some examples herein to refer to various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, first interface and second interface, etc., are used. Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, step, operation, element, module, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, modules, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0041] The technical terms used herein are for reference only to specific embodiments and are not intended to limit the scope of this disclosure. The singular form used herein includes the plural form unless the statement explicitly indicates otherwise. The word "comprising" as used in this specification means to specify a particular characteristic, region, integer, step, operation, element, and / or component, and does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements, and / or components.

[0042] Although not explicitly defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with the relevant technical literature and the message of the present disclosure, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0043] In current tire pressure monitoring systems, the tire pressure sensors are battery-powered, requiring replacement once the battery is depleted. Replacing tire pressure sensors necessitates visits to specialized locations such as dealerships or repair shops, which is inconvenient. Therefore, conserving the power of tire pressure sensors to extend their battery life is an important issue that needs to be addressed.

[0044] When a vehicle leaves the factory or when tires are replaced, the TMPS (Tire Pressure Sensor System) needs to automatically identify and locate the tire position (i.e., determine the location of the tire where the tire pressure sensor is located, such as front left, rear left, front right, or rear right). Currently, the automatic positioning mode of the tire pressure sensor is set to 10 minutes to accommodate all situations. However, in reality, automatic positioning can be completed in as little as 3 minutes, causing the tire pressure sensor to perform unnecessary data acquisition and processing in the remaining time after positioning is completed, resulting in useless power consumption of the tire pressure sensor.

[0045] Furthermore, the amount of data that tire pressure sensors need to transmit is increasing with the growing demands for intelligent automotive systems. For example, they need to collect tire pressure data, tire temperature data, acceleration data along at least two axes, tire thickness data, and so on. Therefore, the amount of data that tire pressure sensors need to wirelessly transmit is constantly increasing, and the requirements for wireless signal transmission speed in automotive intelligence are extremely high. Currently, the commonly used uplink wireless transmission frequencies of 315 or 434 MHz for tire pressure sensors to send data to the tire pressure electronic control unit (TPECU), and the 125 Hz frequency for the TPECU to send commands to the tire pressure sensor, are too low to meet current transmission speed requirements. Therefore, current tire pressure monitoring systems need to balance the power consumption of the tire pressure sensor with the requirements for wireless transmission speed.

[0046] Therefore, this disclosure provides a tire pressure monitoring system to solve the above problems.

[0047] like Figure 1 The diagram illustrates a scenario where the tire pressure monitoring system is applied to a vehicle according to an embodiment of this disclosure.

[0048] The tire pressure monitoring system includes multiple tire pressure sensors 11, 12, 13, and 14 and a tire pressure electronic control unit 20. Figure 1 In the example, vehicle 1 is shown to have four tires: left front (FL), left rear (RL), right front (FR), and right rear (RR). A tire pressure sensor 11, 12, 13, and 14 are fixedly mounted on each tire. When the tire pressure sensors are external, they can be fixed using the tire valve stems. When the tire pressure sensors are internal, they can be fixed to the vehicle rim or tires using methods such as adhesive. Each tire pressure sensor 11, 12, 13, and 14 has a unique identifier, referred to as the tire pressure sensor ID. The left front (FL), left rear (RL), right front (FR), and right rear (RR) tires can also each have their own tire ID.

[0049] The vehicle includes multiple wheel speed sensors 15, 16, 17, and 18. Each wheel speed sensor 15, 16, 17, and 18 is used to collect the level signals of gears 21, 22, 23, and 24 corresponding to the corresponding tire in the vehicle's anti-lock braking system (ABS). Therefore, each wheel speed sensor 15, 16, 17, and 18 can also be referred to as an ABS sensor. When the vehicle is moving, gears 21, 22, 23, and 24 in the ABS system rotate accordingly. Each wheel speed sensor 15, 16, 17, and 18 can periodically collect the level signals of gears 21, 22, 23, and 24 in the ABS system. Each tooth and notch of gears 21, 22, 23, and 24 corresponds to a different level value; for example, a tooth corresponds to a high level, and a notch between teeth corresponds to a low level. The cumulative number of high-level signals over a certain period of time is the number of teeth. The number of teeth corresponds to the change in tire rotation angle during that period of time. Dividing the circumference corresponding to the tire rotation angle by the duration of time yields the wheel speed information. As an example, each gear 21, 22, 23, 24 can be located on the axle of the tire.

[0050] The tire pressure sensors 11, 12, 13, 14 and gears 21, 22, 23, 24 of each tire rotate synchronously as the tire rolls. As an example, the tire pressure sensors 11, 12, 13, 14 and gears 21, 22, 23, 24 of each tire can be arranged coaxially.

[0051] like Figure 2 The diagram shows a schematic of the circuit structure of the tire pressure sensor in an embodiment of this disclosure.

[0052] The tire pressure sensor 3 may include a processor 31, a sensor module and a first Bluetooth communication module 32 connected thereto, and may also include a power supply module 30 for supplying power to other modules. For example, each tire pressure sensor 3 includes its own unique identifier, referred to as the tire pressure sensor ID, which can be added to the data packet of the tire pressure sensor transmitting signals to identify itself.

[0053] In some embodiments, the processor 31 may include a microprocessor unit (MCU) for controlling the sensor module and the first Bluetooth communication module 32.

[0054] The first Bluetooth communication module 32 is used to communicate with the tire pressure electronic control unit (TPECU) via Bluetooth to receive downlink commands from the TPECU, including automatic positioning commands. Additionally, the tire pressure sensor 3 can also transmit the identifier and tire status data uplink via Bluetooth. The content of the tire status data can vary depending on the sensor configuration. For example, the sensor module may include, as shown in the figure, a pressure sensor 33, a temperature sensor 34, an acceleration sensor 35, and an ultrasonic sensor 36, or it may include one or more different combinations thereof. In this case, the tire status data transmitted by the tire pressure sensor 3 may include one or more of the following: tire pressure, tire temperature, acceleration, tire thickness, etc.

[0055] For example, the acceleration sensor 35 can be an acceleration sensor with at least two axes to collect acceleration data along at least two axes. The at least two axes may include two axes along the tire's centripetal direction and one along the tire's tangent. The acceleration sensor 35 can periodically collect acceleration data based on its operating frequency. Based on the acceleration data from both axes, the various angles reached by the acceleration sensor 35 as the wheel rolls can be calculated. The acceleration data can be used in the tire pressure sensor positioning process.

[0056] Back Figure 1 The tire pressure electronic control unit 20 is located on the body of the vehicle 1. Exemplarily, the tire pressure electronic control unit 20 can be arranged on the side of the vehicle body. The tire pressure electronic control unit 20 includes a second Bluetooth communication module for communicating with a first Bluetooth communication module of each tire pressure sensor 11, 12, 13, 14 to issue commands to each tire pressure sensor 11, 12, 13, 14 and receive tire status data from each tire pressure sensor 11, 12, 13, 14. In an automatic positioning scenario, the tire pressure electronic control unit 20 can be triggered to enter an automatic positioning mode, and in response to entering the automatic positioning mode, it sends an automatic positioning command to each tire pressure sensor 11, 12, 13, 14 via Bluetooth communication between the second Bluetooth communication module and the first Bluetooth communication module, causing the tire pressure sensors 11, 12, 13, 14 to enter the automatic positioning mode and send acceleration data to the tire pressure electronic control unit 20 via Bluetooth communication.

[0057] As previously described, each gear rotates as each tire rolls. The teeth and notches of the gears can be detected by the wheel speed sensor as different high and low level signals. By counting the number of high-level teeth, the angle of gear rotation is represented, which corresponds to the angle of tire rotation. The wheel speed sensor obtains the tooth count information by encoding the level signals.

[0058] like Figure 3The diagram shown illustrates a gear in an ABS system according to an embodiment of the present disclosure.

[0059] exist Figure 3 In this system, starting from the positive X-axis of the gear, denoted as the minimum tooth count code value ABS_CODE_MIN, the code increases by one tooth for every tooth the tire rotates counterclockwise, until the tire completes one revolution, at which point the tooth count code reaches its maximum value ABS_CODE_MAX. Afterward, the code starts again from the minimum value. For example, the number of teeth on the wheel can be 48, i.e., ABS_CODE_MIN = 1; ABS_CODE_MAX = 48. Each tooth rotation generates one pulse. Therefore, one revolution of the tire generates 48 pulses, and two revolutions generate 96 pulses.

[0060] like Figure 4 As shown, with each tire rotating, the angle signal calculated from the acceleration data output by the accelerometer can exhibit a sinusoidal curve characteristic, as shown in characteristic curve A. The tooth count encoding data exhibits a periodic sawtooth shape characteristic curve (i.e., from a minimum of 1 to a maximum of 48, then reset to zero and recalculated), as shown in characteristic curve B. It can be understood that because the tire pressure sensor and gear of the same tire are in a fixed relative position (e.g., coaxial) and roll with the tire, there is motion synchronization between the tire pressure sensor and the corresponding gear on each tire. Therefore, characteristic curves A and B for the same tire always maintain the same periodic synchronous shape. Each period corresponds to one rotation of the tire.

[0061] Based on this synchronization characteristic, a reference position that is periodically reached can be selected on the tire rolling path. Theoretically, the tire angle obtained from the acceleration data of the tire pressure sensor on each tire should be consistent with the tire angle indicated by the number of teeth detected by the wheel speed sensor. However, due to the differences in motion between different tires, there will be a significant inconsistency between the acceleration data and the tire angle obtained from the tooth count encoding data at this reference position. Based on this pattern, the tire pressure electronic control unit can locate the tire where each tire pressure sensor is located by matching the consistency characteristics of the acceleration data and tooth count encoding data at the reference position. For example, in... Figure 5In the diagram, the angle corresponding to the peak of characteristic curve A can be selected as the reference position. As can be seen from the vertical dashed line, the tooth count encoding values ​​in each cycle at this reference position (determined by the same moment on the time axis) should theoretically be similar, i.e., consistency in "consistent matching". In other words, for a reference position of the same tire, the tooth count encoding values ​​of the gear passing through this reference position in each cycle can form a set of tooth count encoding values, and the tooth count encoding values ​​in this set should converge at this reference position. For example, 48 teeth correspond to one revolution of the tire, so ideally, the tooth count encoding values ​​corresponding to the same reference position are {b, b+48, b+96, ...}. The better the convergence, the better the "match". As an example, the convergence can be calculated, for example, by calculating the variance or volatility of the set. For example, suppose a tire pressure sensor A selects a reference position X corresponding to a certain time t. Then, for each of the four tires (1, 2, 3, and 4), calculate the set of four tooth count codes C, D, E, and F corresponding to this reference position X (i.e., time t). If C converges while D, E, and F do not, then A is located on tire 1 corresponding to C. Similarly, the correspondence between each of the other tire pressure sensors and each tire can be obtained.

[0062] This section describes an implementation example of a tire pressure electronic control unit (TPECU) acquiring tooth count encoded data. In some embodiments, such as... Figure 1 As shown, the vehicle may further include an ABS electronic control unit 25 and a communication bus 19. The ABS electronic control unit 25 is connected to each wheel speed sensor. The ABS electronic control unit 25 communicates with the tire pressure electronic control unit via the communication bus 19 (such as a CAN bus), sending tooth count encoding data to the tire pressure electronic control unit via the communication bus 19. Furthermore, the tire pressure electronic control unit can obtain the acceleration data via Bluetooth communication with each tire pressure sensor. Then, the tire pressure electronic control unit can execute the tire alignment process of the tire pressure sensors based on the acquired tooth count encoding data and acceleration data. In some examples, the tire pressure electronic control unit receives a bus signal from the CAN bus. The bus signal is periodic and contains tooth count encoding data for the four tire gears corresponding to FL / FR / RR / RL.

[0063] The ABS electronic control unit 25 receives the tooth count encoding values ​​output by ABS sensors 15, 16, 17, and 18, and stores these values ​​in an internal variable in an accumulated manner. After the internal variable accumulates to the maximum value of the ABS variable (ABS_MAX), it restarts counting from the minimum value (ABS_MIN). The ABS electronic control unit 25 processes the tooth count encoding data (i.e., the set of tooth count encoding values) or ABS variables into a data format conforming to the bus protocol and periodically sends it to the CAN bus. Figure 6 The diagram shows an example of the relationship between ABS code values ​​and ABS variables. The correspondence between ABS code values ​​and ABS variables can be illustrated as: ABS code value = (tooth count variable) % ABS_CODE_MAX. The range of ABS tooth count code data can be from 1 to 48, and the range of the tooth count variable can be, for example, from 0 to 1023. Based on the periodic ABS variable, the ABS code value for each period can be calculated.

[0064] As a further example, the step of locating the tire where each tire pressure sensor is located based on the consistency feature matching of the acceleration data and the tooth count encoding data at the reference position of the tire pressure sensor includes: determining the index duration of the tooth count encoding data based on the time interval between the tire pressure sensor moving from an arbitrarily selected reference position to the position where the acceleration data is emitted in the rotation path; obtaining a set of reference values ​​for each tooth count encoding data at the reference position based on the backtracking of the index duration; and determining the tire corresponding to the set of tooth count encoding data reference values ​​with the best convergence at the reference position based on the convergence of the set of tooth count encoding data reference values ​​for each tire's gear.

[0065] For a specific example, let the angle detected by the tire sensor at the current time t be m; let the reference angle be n. Then, in the historical angle data of a preset time period, we look up the historical times corresponding to the previous arrival at angle n. For example, if the previous time was t0, then T = t - t0 is the index duration. If the vehicle moves at a constant speed within this preset time period, then the index duration between every two times the tire moves to the reference angle within this preset time period is equal, so only one index duration needs to be calculated. Using tT, t-2T...t-pT, we obtain the reference value of the tooth count encoding data at each reference position within the preset time period, represented as the set of tooth count encoding data reference values ​​K = {k1, k2, k3...kp}. By analogy, we can obtain four sets of reference values ​​for the number of teeth of the gears corresponding to the four tires: K1, K2, K3, and K4. Then, we can perform the convergence judgment on the four sets of reference values ​​for the number of teeth as in the previous example, and determine that the tire corresponding to the set with the best convergence among K1 to K4 is the tire where tire sensor 1 is located.

[0066] It should be noted that the reference position is a point that can be arbitrarily selected within the tire's rolling path, and not... Figure 5 The example selects specific locations such as peaks or troughs on the angle curve. These locations require complex calculations, such as smoothing the acceleration data to calculate the angle, and determining peaks or troughs by observing specific reversals in the rising and falling trends of the calculated angle. For example, if the acceleration data first increases and then decreases, the turning point is the highest point of the sinusoidal characteristic. If these specific locations were chosen as reference positions, these calculations would be performed frequently, requiring the sensor to remain constantly active, resulting in significant battery consumption. Therefore, choosing any point during tire rotation as the reference position, combined with a method of calculating the number of teeth by tracing back from the current position to the reference position, effectively reduces power consumption while still maintaining automatic positioning functionality.

[0067] exist Figure 1In this example, the electronic tire pressure control unit 20 and each tire pressure sensor 11, 12, 13, and 14 can achieve bidirectional Bluetooth communication (uplink and downlink). Using Bluetooth communication technology instead of the previous radio frequency communication technology allows for low-power bidirectional communication at a lower cost. During the automatic tire positioning process, the electronic tire pressure control unit 20 can control the tire pressure sensors 11, 12, 13, and 14 to enter and exit the automatic positioning mode via Bluetooth start and stop commands. Specifically, when the electronic tire pressure control unit 20 wants to enter the automatic positioning mode, it sends an automatic positioning command Bluetooth signal to each tire pressure sensor 11, 12, 13, and 14 to trigger them to enter the automatic positioning mode. Furthermore, after automatic positioning is completed, the electronic tire pressure control unit 20 can send a stop positioning command Bluetooth signal to the successfully positioned tire pressure sensors 11, 12, 13, and 14, causing them to exit the automatic positioning mode. Therefore, on the one hand, the tire pressure sensors 11, 12, 13, and 14 that have already been successfully positioned do not need to continue data acquisition and transmission in the automatic positioning mode for a preset duration (e.g., 10 minutes), saving unnecessary power consumption. On the other hand, through bidirectional Bluetooth communication (Bluetooth can operate at a 2.4 GHz frequency), the problems of short signal distance and slow transmission rate caused by the original downlink 125 Hz frequency between the tire pressure sensors 11, 12, 13, and 14 and the tire pressure electronic control unit 20 can be solved; and the problem of slow data transmission due to the original low uplink 315 or 434 MHz frequency can also be solved. Meanwhile, Bluetooth has the characteristic of low power consumption. The first and second Bluetooth communication modules can be implemented using Bluetooth 4.0 or higher (4.x, 5.x) modules, and can communicate with terminals (such as mobile phones, vehicle terminals, etc.) to achieve intelligent control.

[0068] Furthermore, in the tire alignment algorithm logic, after determining the index starting point (such as the current position) based on the acceleration data and the index duration relative to the reference position, the reference value set (ABS_Ref) of the tooth count encoding data corresponding to each moment when tire pressure sensors 11, 12, 13, and 14 reach the reference position can be indexed. Since the reference position of the angle curves of the acceleration data of tire pressure sensors 11, 12, 13, and 14 is the same rotation angle, the corresponding ABS tooth counts at the reference point exhibit a convergent distribution, showing a small degree of deviation.

[0069] Because the tire pressure sensors 11, 12, 13, and 14, and gears 21, 22, 23, and 24, are located synchronously (coaxially), the angle curves and other curves from the tire pressure sensors 11, 12, 13, and 14 exhibit a synchronous pattern. Utilizing this characteristic, such as... Figure 4As shown, if the reference point is selected at the same angle as the first signal characteristic curve, the corresponding coaxial second signal encoding value should theoretically converge to a specific value, i.e., exhibit a convergent distribution with a small degree of deviation. Since the CAN bus 19 signal contains tooth count encoding data, the known tooth count encoding data and the synchronization relationship between the first and second signal characteristic curves can be used to achieve the position identification of tire pressure sensors 11, 12, 13, and 14.

[0070] The tire pressure sensors 11, 12, 13, and 14 can operate under preset conditions. In some embodiments, the tire pressure sensors 11, 12, 13, and 14 can enter an operating mode in response to detecting that the vehicle speed has reached a first preset vehicle speed threshold, for example, 20 m / s. In the operating mode, the tire pressure sensors 11, 12, 13, and 14 establish Bluetooth communication with a second Bluetooth communication module via a first Bluetooth communication module to transmit tire status data. That is, the tire pressure sensors 11, 12, 13, and 14 can begin transmitting the tire status data when the vehicle reaches a starting speed of, for example, 20 m / s. The tire pressure electronic control unit 20 can obtain the vehicle speed data detected by the vehicle speed sensor on the vehicle body from the communication bus 19.

[0071] As an example, in operating mode, the tire pressure sensors 11, 12, 13, and 14 can collect data once every one or several minutes and transmit data once every one or several minutes, transmitting multiple frames (e.g., 2, 3, 4, or 5 frames) of data each time. It is understood that the first preset vehicle speed threshold can also be set to, for example, 5, 10, or 15 meters per second, and is not limited to 20 meters per second. In some other embodiments, the tire pressure sensors 11, 12, 13, and 14 can also stop transmitting tire status data in response to detecting a vehicle speed lower than the first preset vehicle speed threshold.

[0072] The tire pressure electronic control unit 20 can also be triggered to enter automatic positioning mode when preset conditions are met, and send automatic positioning commands to tire pressure sensors 11, 12, 13, and 14 via Bluetooth communication to trigger tire pressure sensors 11, 12, 13, and 14 to also enter automatic positioning mode. In some embodiments, the tire pressure electronic control unit 20 is used to enter the automatic positioning mode in response to detecting that the vehicle speed has reached a second preset vehicle speed threshold greater than a first preset vehicle speed threshold, so as to form a Bluetooth communication mode with the first Bluetooth communication module through the second Bluetooth communication module to send automatic positioning commands to tire pressure sensors 11, 12, 13, and 14. That is, the tire pressure electronic control unit 20 can start the automatic positioning mode only after the vehicle speed exceeds the basic speed of the operating mode to a certain extent and reaches a state where tire positioning can be reliably performed. For example, the second preset vehicle speed threshold can be, for example, 30 m / s; or, the second preset threshold can also be other values, such as 25 m / s, 35 m / s, 40 m / s, etc., and is not limited to 30 m / s. In some embodiments, the tire pressure electronic control unit 20 can exit the automatic positioning mode in response to detecting that the vehicle speed is lower than a second preset vehicle speed threshold, and can notify the tire pressure sensors 11, 12, 13, and 14 to exit the automatic positioning mode and enter the operating mode via Bluetooth communication. Correspondingly, in some embodiments, in the automatic positioning mode, the tire pressure sensors 11, 12, 13, and 14 send a preset number of positioning data signals within a preset duration, with the time interval between the transmission of each positioning data signal being randomly set. The preset duration can be, for example, 10 minutes, and the preset number can be, for example, 40. The random interval between positioning data signals is, for example, 15s ± (50~200ms). This random interval mechanism allows the location of the Bluetooth signal transmission to be randomly changed, which can increase the probability of the Bluetooth signal being received. For example, each automatic positioning command includes multiple data frames, each containing acceleration data that can determine the reference position. For example, each positioning data signal can contain 3 data frames, each containing acceleration data, which can index to the reference position (i.e., calculate the reference angle). As an example, the frame interval in each positioning data signal can be a fixed frame interval, such as 70ms.

[0073] In some embodiments, each of the tire pressure sensors 11, 12, 13, and 14 can also be used to send a termination positioning command along with tire status data in response to a preset time period or after sending a number of positioning data signals corresponding to the preset time period without successful positioning. For example, when the automatic positioning mode reaches its time limit (e.g., 10 minutes) or signal quantity limit (e.g., 40 signals), the tire pressure sensors 11, 12, 13, and 14 can exit the automatic positioning mode and send the termination positioning command along with the tire pressure status data that was originally to be sent via Bluetooth signal. Correspondingly, the tire pressure electronic control unit 20 is used to determine whether the positioning result is successful in response to the termination positioning command; if successful, it sends the stop positioning command to the tire pressure sensors 11, 12, 13, and 14 that were determined to have successfully positioned; if unsuccessful, it uses the previous positioning result.

[0074] like Figure 7 The diagram shown illustrates a flowchart of a tire alignment method according to an embodiment of this disclosure. The method can be applied to, for example... Figure 1 The tire pressure electronic control unit in the vehicle in this embodiment. It should be noted that the principle of the tire alignment method has already been explained in the aforementioned tire pressure monitoring system, therefore it will not be repeated in this embodiment.

[0075] The method includes:

[0076] Step S701: In response to entering the automatic positioning mode, an automatic positioning command is sent to each of the tire pressure sensors via Bluetooth communication to cause the tire pressure sensors to enter the automatic positioning mode and send acceleration data to the tire pressure electronic control unit via Bluetooth communication.

[0077] For example, the tire pressure electronic control unit can activate the automatic positioning mode when it detects that the vehicle speed has reached a second preset threshold.

[0078] Step 702: Receive and acquire the acceleration data, and acquire the tooth count encoding data of the wheel speed sensor.

[0079] For example, the tire pressure electronic control unit obtains acceleration data for a certain period of time from each tire pressure sensor via Bluetooth communication, and obtains tooth count encoding data for the corresponding period of time from the communication bus.

[0080] Step S703: Based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensor, locate the tire where each tire pressure sensor is located.

[0081] For example, as described in the previous embodiments, the acceleration data can be used to calculate angles. By selecting a reference position for the reference angle, and extracting reference values ​​of the tooth count encoding data at the same time from the tooth count encoding data based on the various moments when the tire pressure sensor moves to the reference position (i.e., the tire reaches the reference position), a set of reference values ​​of the tooth count encoding data corresponding to each tire is formed. Further, a target set with the best convergence among these sets is obtained, and the tire corresponding to this target set is determined to be the tire where the tire pressure sensor is located.

[0082] Step S704: Send a stop positioning command to the successfully positioned tire pressure sensor via the Bluetooth communication method.

[0083] By using Bluetooth communication to start and stop the automatic positioning of already located tire pressure sensors, the sensors no longer need to perform invalid data acquisition processing for a preset time, effectively saving power. Furthermore, Bluetooth communication offers high signal frequency, fast transmission speed, and good reliability while also being power-efficient.

[0084] The automatic location process is then provided in a specific example.

[0085] [Automatic Positioning Process Example 1]:

[0086] 1. The car owner starts the vehicle;

[0087] 2. When the tire pressure sensor detects a vehicle speed greater than 20 km / h, the tire pressure sensor enters the operating mode and sends data (e.g., data is collected once per minute and sent once per minute, with 3 frames sent at a time).

[0088] 3. When the tire pressure electronic control unit detects that the vehicle speed is greater than 30km / h via the CAN bus, it sends an automatic positioning start command to the tire pressure sensor via Bluetooth; the tire pressure electronic control unit then enters automatic positioning mode.

[0089] 4. After receiving the automatic positioning command, the tire pressure sensor also enters the automatic positioning mode;

[0090] 5. Assume that after 3 minutes on a normal road surface, all tire pressure sensors are successfully located;

[0091] 6. The tire pressure electronic control unit sends a stop automatic positioning command to each tire pressure sensor that has successfully positioned itself via Bluetooth;

[0092] 7. When the tire pressure sensor in automatic positioning mode receives a stop automatic positioning command, it will exit the automatic positioning mode in advance.

[0093] 8. In the above steps, if all sensor positioning fails, all tire pressure sensors will send a termination positioning command to the tire pressure electronic control unit after a preset time (10 minutes in automatic positioning mode) or after sending a preset number (40) positioning data signals. The termination positioning command can be sent along with the tire pressure data sent in operating mode, as part of the normal data. After receiving the termination positioning command from the tire pressure sensors, the tire pressure electronic control unit will forcibly execute the positioning result determination and determine whether the automatic positioning was successful based on the result. If positioning fails, the historical positioning result, i.e., the tire identification number of the previously positioned tire, will be used.

[0094] In the positioning process described in Example 1 of the automatic positioning process above, it is assumed that all tire pressure sensors have been successfully positioned. If all tire pressure sensors are designed to enter and exit the automatic positioning mode together in a bundled manner, then if one or more tire pressure sensors fail to position successfully, causing the entire positioning process to continue for the preset duration of 10 minutes, the remaining tire pressure sensors that have already been positioned successfully (e.g., positioned successfully at 3 minutes) will continue to be in automatic positioning mode, resulting in wasted power consumption. Therefore, in some examples, the tire pressure electronic control unit can independently control the entry and exit of each tire pressure sensor from the automatic positioning mode, allowing tire pressure sensors that have been successfully positioned to exit the automatic positioning mode in a timely manner, thereby saving power consumption.

[0095] The following is an example of an automatic positioning process:

[0096] 1. The car owner starts the vehicle;

[0097] 2. When the tire pressure sensor detects a vehicle speed greater than 20 km / h, the tire pressure sensor enters the operating mode and sends data (data is collected once per minute and sent once per minute, with 3 frames sent at a time);

[0098] 3. When the tire pressure electronic control unit detects that the vehicle speed is greater than 30km / h via the CAN bus, it sends an automatic positioning start command to the tire pressure sensor via Bluetooth; the tire pressure electronic control unit then enters automatic positioning mode.

[0099] 4. After receiving the automatic positioning command, the tire pressure sensor enters the automatic positioning mode;

[0100] 5. Assume the left front tire alignment was successful;

[0101] 6. The tire pressure electronic control unit sends a stop auto-positioning command to the tire pressure sensor of the left front tire via Bluetooth;

[0102] 7. The left front wheel enters the running mode, while the other three sensors remain in the automatic positioning mode. This process continues until all sensors have successfully located the object or have sent 40 packets of positioning data, at which point each sensor exits the positioning mode.

[0103] like Figure 8 The diagram shown illustrates the circuit structure of the tire pressure electronic control unit in an embodiment of this disclosure.

[0104] The tire pressure electronic control unit can execute computer program instructions to achieve the aforementioned embodiments (e.g., Figure 1 The tire pressure electronic control unit in the tire pressure monitoring system can perform, for example... Figure 5 The method and process in the process.

[0105] The tire pressure electronic control unit 800 includes a bus 801, a processor 802, and a memory 803. The processor 802 and the memory 803 can communicate via the bus 801. The memory 803 can store program instructions. The processor 802 implements the method steps in the previous embodiments by running the program instructions in the memory 803, for example... Figure 1 or Figure 6 The method in the middle.

[0106] Bus 801 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, although only one thick line is used in the diagram, this does not indicate that there is only one bus or one type of bus.

[0107] In some embodiments, processor 802 may be implemented as a central processing unit (CPU), microprocessor unit (MCU), system-on-chip (System-on-Chip), or field-programmable array (FPGA). Memory 803 may include volatile memory for temporary data storage during program execution, such as random access memory (RAM).

[0108] The memory 803 may also include non-volatile memory for data storage, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state disk (SSD).

[0109] In some embodiments, the tire pressure electronic control unit 800 may further include a communicator 804. The communicator 804 is used for communication with external devices. In specific examples, the communicator 804 may include one or more wired and / or wireless communication circuit modules. For example, the communicator 804 may include one or more of, such as a wired network card, a USB module, a serial interface module, etc. The wireless communication protocols followed by the wireless communication module include, for example, Nearfield communication (NFC) technology, Infrared (IR) technology, Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Time-Division Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), Bluetooth (BT), Global Navigation Satellite System (GNSS), etc., one or more of these.

[0110] This disclosure also provides a vehicle, including: multiple tires equipped with wheel speed sensors; and vehicles as described in previous embodiments (e.g., Figure 1 The tire pressure monitoring system shown in the image.

[0111] In summary, the tire pressure monitoring system, positioning method, tire pressure electronic control unit, and vehicle in this embodiment of the present disclosure, in response to entering automatic positioning mode, send automatic positioning commands to each of the tire pressure sensors via Bluetooth communication to cause the tire pressure sensors to enter automatic positioning mode and send acceleration data to the tire pressure electronic control unit via Bluetooth communication; receive and acquire the acceleration data, and acquire the tooth count encoding data of the wheel speed sensors; based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensors, locate the tire where each tire pressure sensor is located; and send a stop positioning command to the successfully positioned tire pressure sensors via Bluetooth communication. The tire pressure electronic control unit realizes the start and stop of automatic positioning of the tire pressure sensors and the transmission of tire status data through bidirectional Bluetooth communication, taking into account the power consumption and transmission efficiency of the tire pressure sensors.

[0112] The above embodiments are merely illustrative of the principles and effects of this disclosure and are not intended to limit this disclosure. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this disclosure. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this disclosure should still be covered by the claims of this disclosure.

Claims

1. A tire pressure monitoring system, characterized in that, Applied to vehicles, the anti-lock braking system of the vehicle has gears that rotate with each tire as it rolls, and the vehicle is fixedly equipped with each wheel speed sensor for detecting the gear corresponding to each tire to output tooth count encoded data; the tire pressure monitoring system includes: Multiple tire pressure sensors are fixedly mounted on each of the tires; each tire pressure sensor includes at least two-axis acceleration sensors, which rotate as the tire rolls to output periodic acceleration data related to the rotation angle; each tire pressure sensor includes a first Bluetooth communication module; A tire pressure electronic control unit (TPECU), located in the vehicle, includes a second Bluetooth communication module. In response to entering an automatic positioning mode, the TPECU sends an automatic positioning command to each tire pressure sensor via Bluetooth communication between the second and first Bluetooth communication modules. This causes the tire pressure sensors to enter automatic positioning mode and send acceleration data to the TPECU via Bluetooth communication. The TPECU obtains acceleration data and tooth count encoding data within a preset time period from the automatic positioning command. Based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensor, it locates the tire where each tire pressure sensor is located. Finally, it sends a stop positioning command to the successfully positioned tire pressure sensors via Bluetooth communication. Each tire pressure sensor is configured to send a termination positioning command along with tire status data if positioning fails after a preset time period or after sending a number of positioning data signals corresponding to the preset time period. The tire pressure electronic control unit is configured to determine whether the positioning result is successful in response to the termination positioning command. If successful, it sends the stop positioning command to the tire pressure sensor that was determined to be successfully positioned. If unsuccessful, it uses the previous positioning result. The method of locating the tire where each tire pressure sensor is located based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensor includes: The index duration of the tooth count encoding data is determined based on the time interval between the tire pressure sensor moving from an arbitrarily selected reference position to the position where the acceleration data is transmitted in the rotation path; Based on the backtracking of the index duration, a set of reference values ​​for each tooth count encoded data at the reference position is obtained; Based on the convergence of the tooth count encoding data reference value set corresponding to each tire at the reference position, the tire corresponding to the tooth count encoding data reference value set with the best convergence is determined to be the tire where the tire pressure sensor is located.

2. The tire pressure monitoring system according to claim 1, characterized in that, The reference position is any position on the rotation path of the tire pressure sensor.

3. The tire pressure monitoring system according to claim 1, characterized in that, In the automatic positioning mode, the tire pressure sensor sends a preset number of positioning data signals within a preset time period, and the time interval between the sending actions of each positioning data signal is randomly set; and / or, each automatic positioning command includes multiple data frames, and each data frame contains acceleration data that can determine the reference position.

4. The tire pressure monitoring system according to claim 1, characterized in that, The tire pressure sensor is configured to enter an operating mode in response to detecting that the vehicle speed has reached a first preset vehicle speed threshold. In the operating mode, the tire pressure sensor establishes Bluetooth communication with the second Bluetooth communication module via the first Bluetooth communication module to send tire status data. The tire pressure electronic control unit is configured to enter the automatic positioning mode in response to detecting that the vehicle speed has reached a second preset vehicle speed threshold greater than the first preset vehicle speed threshold. In this mode, the tire pressure sensor establishes Bluetooth communication with the first Bluetooth communication module via the second Bluetooth communication module to send an automatic positioning command to the tire pressure sensor.

5. The tire pressure monitoring system according to claim 1, characterized in that, The tire pressure sensor corresponding to each tire is coaxially arranged with the gear; and / or, the tire pressure electronic control unit obtains the tooth count encoding data from the vehicle communication bus.

6. A tire positioning method, characterized in that, A tire pressure electronic control unit used in a vehicle; each tire of the vehicle is fixedly equipped with a wheel speed sensor and a tire pressure sensor; the method includes: In response to entering the automatic positioning mode, an automatic positioning command is sent to each of the tire pressure sensors via Bluetooth communication to cause the tire pressure sensors to enter the automatic positioning mode and send acceleration data to the tire pressure electronic control unit via Bluetooth communication. Receive and acquire the acceleration data, and acquire the tooth count encoding data of the wheel speed sensor; Based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensor, the tire where each tire pressure sensor is located is located. A stop positioning command is sent to the successfully positioned tire pressure sensor via the Bluetooth communication method. Each tire pressure sensor is configured to send a termination positioning command along with tire status data if positioning fails after a preset time period or after sending a number of positioning data signals corresponding to the preset time period. The tire pressure electronic control unit is configured to determine whether the positioning result is successful in response to the termination positioning command. If successful, it sends the stop positioning command to the tire pressure sensor that was determined to be successfully positioned. If unsuccessful, it uses the previous positioning result. The method of locating the tire where each tire pressure sensor is located based on the consistency feature matching of the acceleration data and tooth count encoding data at the reference position of the tire pressure sensor includes: The index duration of the tooth count encoding data is determined based on the time interval between the tire pressure sensor moving from an arbitrarily selected reference position to the position where the acceleration data is transmitted in the rotation path; Based on the backtracking of the index duration, a set of reference values ​​for each tooth count encoded data at the reference position is obtained; Based on the convergence of the tooth count encoding data reference value set corresponding to each tire at the reference position, the tire corresponding to the tooth count encoding data reference value set with the best convergence is determined to be the tire where the tire pressure sensor is located.

7. A tire pressure electronic control unit, characterized in that, include: Processor and memory; The memory stores program instructions; The processor is configured to run the program instructions to perform the tire alignment method as described in claim 6.

8. A vehicle, characterized in that, include: A plurality of tires equipped with wheel speed sensors; and a tire pressure monitoring system as claimed in any one of claims 1 to 5.

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