Tire pressure monitoring method and system, storage medium and vehicle

Abstract

The invention relates to a tire pressure monitoring method and system, a storage medium and a vehicle, and belongs to the technical field of tire pressure monitoring. Performing image processing on the tire grounding state image to obtain a grounding contour, and fitting the grounding contour into an ellipse to obtain long axis and short axis parameters of the ellipse; calculating a deformation ratio based on long-axis and short-axis parameters of the ellipse; calculating the current tire pressure through a pre-constructed tire pressure calculation model based on the deformation ratio; and judging whether the slow air leakage phenomenon exists in the tire according to the current tire pressure and the standard tire pressure. According to the method, the tire grounding state image can be obtained in real time without adding extra hardware, the cost is reduced by analyzing the tire deformation and judging the current tire pressure state, the influence of low temperature is considered, the slow air leakage condition can be detected, and the monitoring precision is improved.

Description

Technical Field

[0001] This application relates to the field of tire pressure monitoring technology, and in particular to a tire pressure monitoring method and system, a storage medium, and a vehicle. Background Technology

[0002] With the rapid development of automotive technology, people have higher requirements for the safety and reliability of automobiles. Tires are one of the most important components of a car, bearing its weight and directly contacting the road surface. Tire pressure determines the ride comfort and smoothness, as well as the traction between the wheels and the road surface. Safe driving depends on proper tire pressure. If the tire pressure is too low, the contact area between the tire and the ground increases, leading to an abnormal increase in tire internal temperature, severe sidewall deformation that can cause a tire blowout, increased fuel consumption, and reduced tire life. Furthermore, underinflated or leaking tires affect the overall handling of the vehicle, slowing down response and stopping speed. In severe cases, this can cause traffic accidents, resulting in personal injury and property damage. Therefore, to ensure vehicle safety, the implementation of tire pressure monitoring systems is becoming increasingly important.

[0003] Currently, cars and trucks are typically equipped with Tire Pressure Monitoring Systems (TPMS). TPMS uses wireless transmission technology and employs highly sensitive miniature wireless sensors fixed inside the tires to collect tire pressure data whether the vehicle is in motion or stationary. Drivers can view the tire pressure data on the dashboard. Commonly used TPMS are mainly divided into two types: indirect TPMS that uses wheel speed and direct TPMS that uses pressure sensing units.

[0004] Existing TPMS relies on a single sensor inside the tire to collect tire pressure data. When small pinholes or minor leaks occur in the tire or valve core (e.g., leakage rate <0.5 kPa / day), the sensor accuracy cannot detect them in time, leading to an increased false leak rate. At extreme temperatures (-40℃~85℃), sensor drift error increases, and rubber hardening at low temperatures further masks slow leaks. In addition, direct TPMS requires an independent sensor to be installed in each tire, increasing hardware costs and battery maintenance requirements. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this application provides a tire pressure monitoring method and system that can acquire tire contact image in real time without adding extra hardware. By analyzing tire deformation, the current tire pressure status can be determined, reducing costs. Furthermore, considering the impact of low temperatures, it can detect slow leaks, improving monitoring accuracy.

[0006] Firstly, a tire pressure monitoring method is provided for use in vehicles. The method includes: Acquire images of the tire's contact patch status; Image processing is performed on the tire ground contact image to obtain the ground contact profile. The ground contact profile is then fitted into an ellipse to obtain the major and minor axis parameters of the ellipse. The deformation ratio is calculated based on the major and minor axis parameters of the ellipse. The current tire pressure is calculated based on the deformation ratio using a pre-built tire pressure calculation model; Determine if there is a slow leak in the tire based on the current tire pressure and the standard tire pressure.

[0007] In this embodiment, the tire contact patch image is acquired in real time using the vehicle's original hardware (e.g., a camera), eliminating the need for additional sensors and reducing costs. After acquiring the tire contact patch image, it is preprocessed to effectively eliminate noise caused by tire rubber lint, rubber edges, minor scratches, or image sensors, while better preserving edge information to obtain a smooth image. The smooth image is then segmented according to a set threshold to obtain an image contour. The image contour is then filtered and extracted to remove minor defects caused by noise, small tread blocks, or isolated scratches. Small or irrelevant contours are used to obtain the grounding contour; the grounding contour is fitted (for example, using the least squares method to determine the major and minor axis parameters of the ellipse by minimizing the sum of squares of the algebraic distances from the data points to the ellipse), and the major and minor axis parameters of the ellipse are obtained in the process of fitting the grounding contour into the elliptical contour; the deformation ratio is calculated based on the major and minor axis parameters of the ellipse; a tire pressure calculation model is constructed with standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient, and rubber deformation attenuation coefficient as input parameters and the current tire pressure as output, and the tire pressure calculation model parameters are calibrated. During calibration, the number of passengers is determined. If the number of passengers is less than the first set number, the standard tire pressure is calibrated to the average unloaded tire pressure of the set number, and the reference deformation ratio is calibrated to the average unloaded deformation ratio of the set number. If the number of passengers is greater than or equal to the first set number, it is determined whether the number of passengers is less than or equal to the second set number. If the number of passengers is less than or equal to the second set number, the standard tire pressure is calibrated to the average half-loaded tire pressure of the set number, and the reference deformation ratio is calibrated to the average half-loaded deformation ratio of the set number. If the number of passengers is greater than the second set number, the standard tire pressure is calibrated... To collect a set number of average full-load tire pressures, the baseline deformation ratio is calibrated to the average full-load deformation ratio of the collected set number of tires. The current temperature is acquired, and based on the current temperature and a set temperature compensation value, a rubber deformation attenuation coefficient is obtained through bench testing. The current road surface condition is acquired, and a deformation ratio correction coefficient is calibrated based on the road surface condition. The current tire pressure is calculated using a calibrated tire pressure calculation model based on the deformation ratio. The difference between the current tire pressure and the standard tire pressure is used to determine if a slow leak is present. When a slow leak is detected, an alarm is issued to alert the driver. This tire pressure monitoring method acquires tire contact image data in real time without adding extra hardware, reducing costs. By processing the tire contact image data, the major and minor axis parameters of the ellipse are obtained, the deformation ratio is calculated, and a tire pressure calculation model is constructed. The parameters of the tire pressure calculation model are calibrated based on load conditions, temperature, and driving scenarios to calculate the current tire pressure in real time. This allows for more accurate and rapid detection of slow leaks, improving detection precision, preventing accidents, and enhancing vehicle safety.

[0008] In conjunction with the first aspect, in some implementations of the first aspect, the method for obtaining the ground contact profile by image processing of the tire ground contact state image is as follows: Preprocess the tire contact image to obtain a smooth image; The smoothed image is segmented according to a set threshold to obtain the image contour; The image contours are filtered and extracted to obtain the grounding contours.

[0009] In this embodiment, the tire contact patch image is preprocessed by converting the color image to a grayscale image to reduce data volume, highlight texture and brightness information, and further smooth the image (e.g., using a Gaussian filtering algorithm to smooth the image), effectively eliminating noise caused by tire rubber lint, rubber edges, minor scratches, or image sensors, while better preserving imprint edge information, resulting in a smooth image. The smoothed image is then segmented according to a set threshold (e.g., by setting a threshold, the grayscale image is converted to a binary image containing only black and white, thus separating the tire contact patch contour from the background) to obtain an image contour. The image contour is then filtered and extracted (e.g., by searching for all connected regions (i.e., contours) in the binary image), removing tiny or irrelevant contours caused by noise, small tread blocks, independent scratches, etc., to obtain the contact patch contour. The contact patch contour is then fitted (e.g., using the least squares method, by minimizing the sum of squares of the algebraic distances from data points to the ellipse to determine the major and minor axis parameters of the ellipse), obtaining the major and minor axis parameters of the ellipse during the process of fitting the contact patch contour to the elliptical contour. This method allows for real-time acquisition of the tire contact patch image, enabling real-time tire pressure detection.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the method for calculating the deformation ratio is as follows: the deformation ratio is calculated using the ratio of the major axis to the minor axis of the ellipse.

[0011] In this embodiment of the application, the deformation ratio calculated using the ratio of the major axis to the minor axis of the ellipse can be expressed as: ; in, For deformation ratio, Let be the major axis of the ellipse. Let be the minor axis of the ellipse.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the method for constructing the tire pressure calculation model is as follows: using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient and rubber deformation attenuation coefficient as input parameters, and using the current tire pressure as output, the tire pressure calculation model is constructed.

[0013] In this embodiment of the application, the tire pressure calculation model is constructed as follows: ; in, This is the current tire pressure. Standard tire pressure As the reference deformation ratio, For deformation ratio, This is the deformation ratio correction factor. This is the rubber deformation attenuation coefficient.

[0014] In this embodiment, a tire pressure calculation model is constructed using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction factor, and rubber deformation attenuation factor as input parameters, and current tire pressure as output. The current tire pressure is reflected through the deformation ratio, standard tire pressure, reference deformation ratio, deformation ratio correction factor, and rubber deformation attenuation factor. This method can incorporate real-time load conditions, temperature conditions, and road conditions into the tire pressure calculation.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the method for calibrating the parameters of the tire pressure calculation model is as follows: Determine if the number of passengers is less than a first preset number; When the number of passengers is less than the first set number, the standard tire pressure is calibrated to the average value of the unloaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average value of the unloaded deformation ratio of the set number of passengers; when the number of passengers is greater than or equal to the first set number, it is determined whether the number of passengers is less than or equal to the second set number. When the number of passengers is less than or equal to the second set number, the standard tire pressure is calibrated to the average half-load tire pressure of the set number, and the reference deformation ratio is calibrated to the average half-load deformation ratio of the set number. When the number of passengers exceeds the second set number, the standard tire pressure is calibrated to the average value of the full-load tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average value of the full-load deformation ratio of the set number of passengers.

[0016] In this embodiment, since the number of passengers also affects tire pressure, when calibrating the standard tire pressure and reference deformation ratio of the tire pressure calculation model, it is necessary to determine the number of passengers. When the number of passengers is less than a first set number, the standard tire pressure is calibrated to the average unloaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average unloaded deformation ratio of the set number of passengers. When the number of passengers is greater than or equal to the first set number, it is determined whether the number of passengers is less than or equal to a second set number. When the number of passengers is less than or equal to the second set number, the standard tire pressure is calibrated to the average half-loaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average half-loaded deformation ratio of the set number of passengers. When the number of passengers is greater than the second set number, the standard tire pressure is calibrated to the average fully loaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average fully loaded deformation ratio of the set number of passengers. This method can calculate the standard tire pressure and reference deformation ratio by calibrating them to different values ​​according to different passenger numbers (i.e., load), thus achieving dynamic tire pressure calculation.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the method for calibrating the parameters of the tire pressure calculation model is as follows: Get the current temperature; Based on the current temperature and the set temperature compensation value, the rubber deformation attenuation coefficient is obtained through bench testing.

[0018] In this embodiment, when calibrating the rubber deformation attenuation coefficient of the tire pressure calculation model, the rubber deformation is affected by temperature, and the rubber deformation coefficient is different at different temperatures. Therefore, it is necessary to obtain the current temperature and, based on the current temperature and a set temperature compensation value, to obtain the rubber deformation attenuation coefficient through bench testing. This method takes into account the influence of temperature on tire hardness and can improve monitoring accuracy.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the method for calibrating the parameters of the tire pressure calculation model is as follows: Get the current road surface status; The deformation ratio correction factor is determined based on the road surface condition.

[0020] In this embodiment, due to different driving scenarios (e.g., flat urban roads, highway roads, unpaved roads), the road surface conditions in contact with the tires also differ. The deformation ratio obtained from the ground contact image is affected by these road surface conditions, resulting in some error. Therefore, a deformation ratio correction coefficient needs to be calibrated based on the road surface conditions, and the deformation ratio is corrected using this calibrated coefficient. This method can correct the deformation ratio for different road surface conditions, eliminating the influence of road surface conditions on tire pressure calculation and improving monitoring accuracy.

[0021] In conjunction with the first aspect, in some implementations of the first aspect, the method for determining whether a tire is experiencing slow air leakage based on the current tire pressure and the standard tire pressure is as follows: Determine if the difference between the current tire pressure and the standard tire pressure is greater than a set threshold; If the air pressure exceeds a set threshold for an extended period of time, the tire is determined to be leaking slowly.

[0022] In this embodiment of the application, determining whether the difference between the current tire pressure and the standard tire pressure is greater than a set threshold can be expressed as: ; in, The current tire pressure is... Standard tire pressure To set a threshold.

[0023] In conjunction with the first aspect, in some implementations of the first aspect, when it is determined that there is a slow leak in the tire, the alarm device is controlled to issue an alarm.

[0024] In this embodiment of the application, when a slow air leak is detected in the tire, an alarm can be issued to remind the driver that the vehicle is leaking air slowly, which greatly avoids accidents and improves driving safety.

[0025] Secondly, a tire pressure monitoring system is provided for use in vehicles. This system includes: The acquisition module is used to acquire images of the tire's ground contact status. An image processing module, connected to the acquisition module, is used to perform image processing on the tire ground contact state image to obtain a ground contact contour, fit the ground contact contour into an ellipse, and obtain the major axis and minor axis parameters of the ellipse. The calculation module, connected to the image processing module, is used to calculate the deformation ratio based on the major and minor axis parameters of the ellipse, and to calculate the current tire pressure based on the deformation ratio using a pre-built tire pressure calculation model. The judgment module is connected to the calculation module, and the judgment module is set to determine whether there is a slow air leak in the tire based on the current tire pressure and the standard tire pressure.

[0026] In conjunction with the second aspect, in some implementations of the second aspect, the system further includes: The model building module, connected to the calculation module, is used to build a tire pressure calculation model with standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient and rubber deformation attenuation coefficient as input parameters and current tire pressure as output. A calibration module, connected to the model building module and the calculation module, is used to calibrate the parameters of the tire pressure calculation model. Alarm devices are used to issue alarms; A control module is connected to the judgment module and the alarm device. The control module is configured to control the alarm device to issue an alarm when it is determined that there is a slow air leak in the tire.

[0027] In conjunction with the second aspect, in some implementations of the second aspect, the image processing module preprocesses the tire ground contact state image to obtain a smooth image; the image processing module performs image segmentation on the smooth image according to a set threshold to obtain an image contour; the image processing module filters and extracts the image contour to obtain a ground contact contour.

[0028] In conjunction with the second aspect, in some implementations of the second aspect, the calculation module calculates the deformation ratio using the ratio of the major axis to the minor axis of the ellipse.

[0029] In conjunction with the second aspect, in some implementations of the second aspect, when the number of passengers is less than a first set number, the calibration module calibrates the standard tire pressure to the average unloaded tire pressure of the set number of passengers collected, and calibrates the reference deformation ratio to the average unloaded deformation ratio of the set number of passengers collected; when the number of passengers is less than or equal to a second set number, the calibration module calibrates the standard tire pressure to the average half-loaded tire pressure of the set number of passengers collected, and calibrates the reference deformation ratio to the average half-loaded deformation ratio of the set number of passengers collected; when the number of passengers is greater than the second set number, the calibration module calibrates the standard tire pressure to the average fully loaded tire pressure of the set number of passengers collected, and calibrates the reference deformation ratio to the average fully loaded deformation ratio of the set number of passengers collected; the calibration module obtains the rubber deformation attenuation coefficient by fitting the current temperature and the set temperature compensation value through bench experiments; the calibration module calibrates the deformation ratio correction coefficient according to the road surface condition.

[0030] In conjunction with the second aspect, in some implementations of the second aspect, the judgment module is further configured to: determine whether the number of passengers is less than a first set number; when the number of passengers is greater than or equal to the first set number, determine whether the number of passengers is less than or equal to a second set number; and determine whether the difference between the current tire pressure and the standard tire pressure is greater than a set threshold.

[0031] In conjunction with the second aspect, in some implementations of the second aspect, the acquisition module is also used to acquire the current temperature and the current road surface condition.

[0032] In conjunction with the second aspect, in some implementations of the second aspect, when the time exceeds a set threshold for a first set time period, the judgment module determines that the tire is experiencing slow air leakage.

[0033] Thirdly, a computer program product is provided, the computer program product comprising: computer program code, which, when run on a computer, causes the computer to perform the tire pressure monitoring method of the first aspect described above.

[0034] Fourthly, a computer-readable storage medium is provided that stores computer program code, which is executed by one or more processors, such that when the computer program code is run on a processor, an apparatus including the one or more processors performs the tire pressure monitoring method of the first aspect described above.

[0035] Fifthly, embodiments of this application provide a chip system, the chip system including a processor for calling a computer program or computer instructions stored in a memory, so that the processor executes the tire pressure monitoring method of the first aspect described above.

[0036] In a sixth aspect, an electronic device according to an embodiment of this application includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the electronic device implements the tire pressure monitoring method of the first aspect.

[0037] In a seventh aspect, a vehicle is provided. The vehicle includes the tire pressure monitoring system described in the second aspect above, or the computer-readable storage medium described in the fourth aspect above, or the chip system described in the fifth aspect above, or the electronic device described in the sixth aspect above.

[0038] The beneficial effects of the technical solutions provided in this application include at least the following: In this embodiment, the tire contact patch image is acquired in real time using the vehicle's original hardware (e.g., a camera), eliminating the need for additional sensors and reducing costs. After acquiring the tire contact patch image, it is preprocessed to effectively eliminate noise caused by tire rubber lint, rubber edges, minor scratches, or image sensors, while better preserving edge information to obtain a smooth image. The smooth image is then segmented according to a set threshold to obtain an image contour. This image contour is then filtered and extracted to remove tiny or irrelevant contours caused by noise, small tread blocks, or independent scratches, resulting in a contact patch contour. Finally, the contact patch contour is fitted (e.g., using the least squares method). The major and minor axis parameters of the ellipse are determined by minimizing the sum of squares of the algebraic distances from the data points to the ellipse. These parameters are obtained during the process of fitting the ground contact profile to the elliptical profile. The deformation ratio is calculated based on these parameters. A tire pressure calculation model is constructed using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient, and rubber deformation attenuation coefficient as input parameters, with the current tire pressure as the output. The parameters of the tire pressure calculation model are then calibrated. The current tire pressure is calculated using the calibrated tire pressure calculation model based on the deformation ratio. The difference between the current tire pressure and the standard tire pressure is used to determine if there is a slow leak. When a slow leak is detected, an alarm is issued to alert the driver. This tire pressure monitoring method acquires real-time images of the tire's contact patch without adding extra hardware, reducing costs. By processing these images, the major and minor axis parameters of the ellipse are obtained, the deformation ratio is calculated, and a tire pressure calculation model is constructed. The model parameters are calibrated based on load conditions, temperature, and driving scenarios to calculate the current tire pressure in real time and determine whether the tire is experiencing a slow leak. This allows for more accurate and rapid detection of slow leaks, improving detection precision, preventing accidents, and enhancing vehicle safety.

[0039] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of this application more obvious, specific embodiments of this application are given below. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1This is a schematic diagram of the tire pressure monitoring method according to an embodiment of this application.

[0042] Figure 2 This is a schematic flowchart of an image processing method according to an embodiment of this application.

[0043] Figure 3 This is a schematic flowchart illustrating a method for calibrating tire pressure calculation model parameters according to an embodiment of this application.

[0044] Figure 4 This is a schematic flowchart illustrating a method for calibrating tire pressure calculation model parameters according to another embodiment of this application.

[0045] Figure 5 This is a schematic flowchart illustrating a method for calibrating tire pressure calculation model parameters according to another embodiment of this application.

[0046] Figure 6 This is a schematic diagram of the architecture of the tire pressure monitoring system according to an embodiment of this application.

[0047] Figure 7 This is a schematic diagram of the vehicle architecture according to an embodiment of this application.

[0048] In the diagram, 100 is the tire pressure monitoring system, 101 is the acquisition module, 102 is the image processing module, 103 is the calculation module, 104 is the model building module, 105 is the calibration module, 106 is the judgment module, 107 is the control module, 108 is the alarm device, 200 is the vehicle, 201 is the memory, 202 is the processor, and 203 is the computer program. Detailed Implementation

[0049] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0050] The prefixes such as "first" and "second" used in this application embodiment are merely for distinguishing different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes used to distinguish descriptive objects in this application embodiment does not constitute a limitation on the described objects. The description of the described objects is given in the claims or the context of the embodiments, and should not constitute unnecessary restrictions due to the use of such prefixes. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0051] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0052] In the embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0053] With the rapid development of automotive technology, people have higher requirements for the safety and reliability of automobiles. Car tires are one of the most important components of a car, bearing its weight and directly contacting the road surface. Tire pressure determines the ride comfort and smoothness, as well as the adhesion between the wheels and the road surface. Safe driving depends on proper tire pressure. When tire pressure is too high, the contact area between the tire and the ground decreases, leading to a significant increase in pressure and wear per unit area. This can easily cause brake failure, cause severe bumps on uneven roads, negatively impacting the driving experience, and may even lead to tire blowouts. Conversely, when tire pressure is too low, the contact area between the tire and the ground increases, causing abnormal increases in tire internal temperature during driving. This can lead to severe sidewall deformation, resulting in tire blowouts, increased fuel consumption, and reduced tire lifespan.

[0054] Insufficiently inflated or leaking tires can affect a vehicle's overall handling, slowing down its response and stopping speed. In severe cases, this can lead to traffic accidents, causing personal injury and property damage. To ensure vehicle safety, tire pressure monitoring systems are becoming increasingly important. How to detect slow leaks in tires in real time has become a pressing technical problem that needs to be solved.

[0055] Tire Pressure Monitoring System (TPMS) is primarily used for real-time automatic monitoring of tire pressure and temperature. It issues alarms and warnings when abnormal tire conditions are detected, alerting the driver to take appropriate measures to ensure driving safety. Currently, cars and trucks are typically equipped with TPMS. TPMS uses wireless transmission technology, employing highly sensitive miniature wireless sensors fixed inside the tires to collect tire pressure data whether the vehicle is in motion or stationary. The driver can view the tire pressure data on the dashboard.

[0056] Commonly used Tire Pressure Monitoring Systems (TPMS) are mainly divided into two types: indirect TPMS, which uses wheel speed, and direct TPMS, which uses pressure sensing units. Direct TPMS (Pressure-Sensor Based TPMS, or PSB) uses pressure sensors installed on the tires to measure tire pressure. A wireless transmitter sends the pressure information from inside the tire to a central receiver module, which then displays the tire pressure data. When the tire pressure is low or there is a leak, the system will issue an alarm. Therefore, direct TPMS is a type of active TPMS. Indirect TPMS (Wheel-Speed ​​Based TPMS, also known as WSB) relies on the wheel speed sensors of the vehicle's ABS (Anti-lock Braking System) to compare the speed differences between the tires to monitor tire pressure. ABS is an active safety device that maintains vehicle handling and directional stability by preventing wheel lock-up during emergency braking. Its core components include wheel speed sensors, a main control unit, a brake pressure regulator, and warning lights, enabling real-time monitoring of wheel speed and dynamic adjustment of braking force. ABS uses wheel speed sensors to determine if a wheel is locked, thus deciding whether to activate the anti-lock braking system. When tire pressure decreases, the vehicle's weight causes the tire diameter to shrink, resulting in a change in vehicle speed. This speed change triggers the WSB (Wheel Brake Brake) warning system, alerting the driver to low tire pressure. Therefore, indirect TPMS (Tire Pressure Monitoring System) is a type of passive TPMS. Existing TPMS relies on a single sensor inside the tire to collect tire pressure data. When small pinholes or minor leaks occur in the tire or valve core (e.g., leakage rate <0.5 kPa / day), the sensor accuracy cannot detect them in time, leading to an increased false leak rate. At extreme temperatures (-40℃~85℃), the sensor drift error increases due to temperature effects. Low temperatures and rubber hardening can further mask slow leaks, increasing the difficulty of identifying slow tire leaks. In addition, TPMS requires an independent sensor for each tire, increasing hardware costs and battery maintenance requirements.

[0057] In response to the above situation, there is an urgent need for a tire pressure monitoring method that can acquire images of the tire's contact with the ground in real time without adding extra hardware, and calculate the current tire pressure based on the acquired images. This method can more accurately and quickly detect slow leaks, improve detection accuracy, and reduce costs.

[0058] Based on the above application scenarios, this application proposes a tire pressure monitoring method.

[0059] Figure 1 This is a schematic flowchart illustrating a tire pressure monitoring method provided in this embodiment. The method is applicable to vehicles. The method includes the following steps.

[0060] S1. Obtain the tire ground contact status image.

[0061] In this embodiment, the tire contact status image is acquired in real time using the vehicle's original hardware (such as a camera), eliminating the need for additional sensors, thus solving the sensor battery maintenance requirement and reducing costs.

[0062] In one exemplary embodiment, the vehicle's existing wide-angle cameras (such as 120° field-of-view cameras or 360° panoramic cameras) are used to capture tire contact patch images at a frame rate of 30fps. Typically, at least four cameras are required, one independently installed near each tire, to ensure comprehensive coverage of the side views of all tires and accurate capture of their respective contact patch images. The contact patch images of each tire can be obtained using the vehicle's existing cameras. For example, cameras located under the front and rear bumpers capture contact patch images of the front and rear sides of the wheels, while side skirts or chassis edge cameras capture side contact patch images, which is particularly helpful for observing tire deformation. Side-view cameras in the 360° panoramic imaging system below the rearview mirrors can acquire tire contact patch images from all directions, supplementing images of contact patch areas not captured by other cameras.

[0063] S2. Perform image processing on the tire ground contact image to obtain the ground contact profile, fit the ground contact profile into an ellipse, and obtain the major axis and minor axis parameters of the ellipse.

[0064] In this embodiment, after acquiring the tire ground contact image, the tire ground contact image is preprocessed to effectively eliminate noise caused by tire rubber hairs, rubber edges, minor scratches, or image sensors, while better preserving the edge information of the ground contact image to obtain a smooth image; the smooth image is segmented according to a set threshold to obtain an image contour; the image contour is filtered and extracted to remove tiny or irrelevant contours caused by noise, small tread blocks, independent scratches, etc., to obtain the ground contact contour; the ground contact contour is fitted (for example, using the least squares method to determine the major and minor axis parameters of the ellipse by minimizing the sum of squares of the algebraic distances from the data points to the ellipse), to obtain the major and minor axis parameters of the ellipse.

[0065] In one embodiment of this application, see Figure 2 The method for image processing of tire contact image is as follows: S201. Preprocess the tire contact state image to obtain a smooth image; S202. Perform image segmentation on the smoothed image according to a set threshold to obtain the image contour; S203. Filter and extract the image contours to obtain the grounding contours.

[0066] In this embodiment, the tire contact patch image is preprocessed by converting the color image to a grayscale image to reduce data volume, highlight texture and brightness information, and further smooth the image (e.g., using a Gaussian filtering algorithm to smooth the image), effectively eliminating noise caused by tire rubber lint, rubber edges, minor scratches, or image sensors, while better preserving imprint edge information, resulting in a smooth image. The smoothed image is then segmented according to a set threshold (e.g., by setting a threshold, the grayscale image is converted to a binary image containing only black and white, thus separating the tire contact patch contour from the background) to obtain an image contour. The image contour is then filtered and extracted (e.g., by searching for all connected regions (i.e., contours) in the binary image), removing tiny or irrelevant contours caused by noise, small tread blocks, independent scratches, etc., to obtain the contact patch contour. The contact patch contour is then fitted (e.g., using the least squares method, by minimizing the sum of squares of the algebraic distances from data points to the ellipse to determine the major and minor axis parameters of the ellipse), obtaining the major and minor axis parameters of the ellipse during the process of fitting the contact patch contour to the elliptical contour. This method allows for real-time acquisition of the tire contact patch image, enabling real-time tire pressure detection.

[0067] Grayscale images are typically obtained by measuring the brightness of each pixel within a single electromagnetic spectrum (such as visible light). Grayscale images used for display are usually stored using a non-linear scale of 8 bits per sampled pixel, resulting in 256 gray levels. This precision is just enough to avoid visible striping distortion and is very easy to program. However, in technical applications such as medical imaging and remote sensing imaging, more levels are often used to fully utilize the sensor precision of 10 or 12 bits per pixel and avoid approximation errors during calculation. In these applications, 16 bits per pixel, or 65,536 levels, has become popular.

[0068] A binary image is an image where every pixel is either black or white. Binary images are generally used to describe character images. Their advantage is that they take up little space. However, their disadvantage is that when representing images of people or landscapes, binary images can only display edge information, and the internal texture features are not clearly shown. In such cases, grayscale images with richer texture features should be used. A binary image is a digital image where each pixel has only two possible values, but it can also be used to represent any image where each pixel has only one sampled value, such as grayscale images. All pixels in a binary image can only take values ​​from 0 and 1. In MATLAB, a binary image is represented by a two-dimensional matrix of 0s and 1s. These two possible values ​​correspond to "off" and "on," respectively. "Off" indicates that the pixel is in the background, and "on" indicates that the pixel is in the foreground. Manipulating images in this way makes it easier to identify the structural features of the image. Binary image operations only return information related to the form or structure of the binary image. If you want to perform the same operations on other types of images, you must first convert them to a binary image format, which can be achieved by calling the im2bw function provided by MATLAB. Binary images are frequently used in digital image processing as image masks or in the results of image segmentation, binarization, and dithering. Some input / output devices, such as laser printers, fax machines, and monochrome computer monitors, can also process binary images.

[0069] Gaussian filtering is a linear smoothing filter suitable for eliminating Gaussian noise and widely used in image processing for noise reduction. Simply put, Gaussian filtering is a weighted average process applied to the entire image. The value of each pixel is obtained by weighted averaging of its own value and the values ​​of its neighboring pixels. Specifically, Gaussian filtering works by scanning every pixel in the image with a template (or convolution, mask), and replacing the value of the center pixel of the template with the weighted average gray value of the pixels in the neighborhood defined by the template.

[0070] Ordinary least squares (OLS) is a mathematical optimization technique that finds the best function fit for data by minimizing the sum of squared errors. It is used for parameter estimation and curve fitting. This method possesses linearity, unbiasedness, and minimum variance (BLU) properties, and its estimators satisfy the Gauss-Markov theorem. Based on a selected combination of linearly independent functions, it solves unconstrained optimization problems by minimizing the sum of squared errors, and is applicable to both linear and nonlinear least squares cases. Its core principle is minimizing the sum of squared differences between all estimated values ​​and the estimated value. This can be achieved by expressing the error as the norm squared using matrix methods for optimization.

[0071] S3. Calculate the deformation ratio based on the major and minor axis parameters of the ellipse.

[0072] In this embodiment, the major and minor axis parameters of the ellipse are substituted into the deformation ratio calculation formula to calculate the deformation ratio. Based on the deformation ratio, tire pressure is further calculated, providing data support for determining tire pressure status using tire contact patch images. The accuracy can reach [a certain level]. This improves the accuracy of tire pressure monitoring.

[0073] In one embodiment of this application, the method for calculating the deformation ratio is as follows: the deformation ratio is calculated using the ratio of the major axis to the minor axis of the ellipse.

[0074] In this embodiment of the application, the deformation ratio calculated using the ratio of the major axis to the minor axis of the ellipse can be expressed as: ; in, For deformation ratio, Let be the major axis of the ellipse. Let be the minor axis of the ellipse.

[0075] S4. Calculate the current tire pressure based on the deformation ratio using a pre-built tire pressure calculation model.

[0076] In this embodiment, a tire pressure calculation model is first constructed using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient, and rubber deformation attenuation coefficient as input parameters, and the current tire pressure as the output. The input parameters of the tire pressure calculation model are then calibrated. During calibration, the standard tire pressure and reference deformation ratio are calibrated based on the number of passengers. The rubber deformation attenuation coefficient is obtained through bench testing by fitting the current temperature with the set temperature compensation value. The deformation ratio correction coefficient is calibrated based on the driving scenario. Finally, the current tire pressure is calculated using the calibrated tire pressure calculation model based on the deformation ratio. This method considers the influence of vehicle load (i.e., number of passengers), temperature, and road surface conditions (i.e., driving scenario) on tire deformation (i.e., tire contact image) during parameter calibration, reducing tire pressure calculation errors and improving the accuracy of tire pressure monitoring.

[0077] In one embodiment of this application, the method for constructing a tire pressure calculation model is as follows: using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient and rubber deformation attenuation coefficient as input parameters, and using the current tire pressure as output, a tire pressure calculation model is constructed.

[0078] In one embodiment of this application, the tire pressure calculation model is as follows: ; in, This is the current tire pressure. Standard tire pressure As the reference deformation ratio, For deformation ratio, This is the deformation ratio correction factor. This is the rubber deformation attenuation coefficient.

[0079] In this embodiment, a tire pressure calculation model is constructed using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction factor, and rubber deformation attenuation factor as input parameters, and current tire pressure as output. The current tire pressure is reflected through the deformation ratio, standard tire pressure, reference deformation ratio, deformation ratio correction factor, and rubber deformation attenuation factor. This method can incorporate real-time load conditions, temperature conditions, and road conditions into the tire pressure calculation.

[0080] In one embodiment of this application, see Figure 3 The method for calibrating the tire pressure calculation model parameters is as follows: S301. Determine whether the number of passengers is less than the first preset number; S302. When the number of passengers is less than the first set number, the standard tire pressure is calibrated to the average value of the unloaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average value of the unloaded deformation ratio of the set number of passengers. S303. When the number of passengers is greater than or equal to the first preset number, determine whether the number of passengers is less than or equal to the second preset number; S304. When the number of passengers is less than or equal to the second set number, the standard tire pressure is calibrated to the average half-load tire pressure of the set number collected, and the reference deformation ratio is calibrated to the average half-load deformation ratio of the set number collected. S305. When the number of passengers exceeds the second set number, the standard tire pressure is calibrated to the average value of the full-load tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average value of the full-load deformation ratio of the set number of passengers.

[0081] In this embodiment, since the number of passengers also affects tire pressure, when calibrating the standard tire pressure and reference deformation ratio of the tire pressure calculation model, it is necessary to determine the number of passengers. When the number of passengers is less than a first set number, the standard tire pressure is calibrated to the average unloaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average unloaded deformation ratio of the set number of passengers. When the number of passengers is greater than or equal to the first set number, it is determined whether the number of passengers is less than or equal to a second set number. When the number of passengers is less than or equal to the second set number, the standard tire pressure is calibrated to the average half-loaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average half-loaded deformation ratio of the set number of passengers. When the number of passengers is greater than the second set number, the standard tire pressure is calibrated to the average fully loaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average fully loaded deformation ratio of the set number of passengers. This method can calculate the standard tire pressure and reference deformation ratio by calibrating them to different values ​​according to different passenger numbers (i.e., load), thus achieving dynamic tire pressure calculation.

[0082] In this embodiment, the average unloaded tire pressure, average unloaded deformation ratio, average half-loaded tire pressure, average half-loaded deformation ratio, average fully loaded tire pressure, and average fully loaded deformation ratio can be obtained through on-site calibration measurements before the vehicle leaves the factory, for example, by collecting 100 sets of data and taking the average value. The first and second preset quantities are set before the vehicle leaves the factory according to the vehicle model. For example, for a five-seater vehicle, the first preset quantity can be set to 2, and the second preset quantity can be set to 4.

[0083] In one embodiment of this application, see Figure 4 The method for calibrating the tire pressure calculation model parameters is as follows: S311, Obtain the current temperature; S312. Based on the current temperature and the set temperature compensation value, the rubber deformation attenuation coefficient is obtained through bench testing.

[0084] In this embodiment, when calibrating the rubber deformation attenuation coefficient of the tire pressure calculation model, the rubber deformation is affected by temperature, and the rubber deformation coefficient is different at different temperatures. Therefore, it is necessary to obtain the current temperature and, based on the current temperature and a set temperature compensation value, to obtain the rubber deformation attenuation coefficient through bench testing. This method takes into account the influence of temperature on tire hardness and can improve monitoring accuracy.

[0085] In one embodiment of this application, see Figure 5 The method for calibrating the tire pressure calculation model parameters is as follows: S321. Obtain the current road surface status; S322. Determine the deformation ratio correction coefficient based on the road surface condition.

[0086] In this embodiment, due to different driving scenarios (e.g., flat urban roads, highway roads, unpaved roads), the road surface conditions in contact with the tires also differ. The deformation ratio obtained from the ground contact image is affected by these road surface conditions, resulting in some error. Therefore, a deformation ratio correction coefficient needs to be calibrated based on the road surface conditions, and the deformation ratio is corrected using this calibrated coefficient. This method can correct the deformation ratio for different road surface conditions, eliminating the influence of road surface conditions on tire pressure calculation and improving monitoring accuracy.

[0087] In this embodiment of the application, the deformation ratio correction coefficient is calibrated according to the road surface condition to correct the deformation ratio for different road surface conditions. For example, when the road surface condition is a flat urban road surface, the calibration deformation ratio correction coefficient is 0.95; when the road surface condition is a highway road surface, the deformation ratio does not need to be adjusted, and the calibration deformation ratio correction coefficient is 1.0; when the road surface condition is an unpaved road surface, the calibration deformation ratio correction coefficient is 1.05.

[0088] S6. Determine if there is a slow leak in the tire based on the current tire pressure and the standard tire pressure.

[0089] In one embodiment of this application, the method for determining whether a tire is experiencing slow air leakage based on the current tire pressure and the standard tire pressure is as follows: Determine if the difference between the current tire pressure and the standard tire pressure is greater than a set threshold; If the air pressure exceeds a set threshold for an extended period of time, the tire is determined to be leaking slowly.

[0090] In this embodiment of the application, determining whether the difference between the current tire pressure and the standard tire pressure is greater than a set threshold can be expressed as: ; in, The current tire pressure is... Standard tire pressure To set a threshold.

[0091] In this embodiment of the application, when the tire pressure is continuously greater than a set threshold within a first set time period, it is determined that there is a slow air leak in the tire. The alarm device can be controlled to issue an alarm to remind the driver that there is a slow air leak in the vehicle, so as to avoid accidents that may occur due to tire leaks and improve vehicle safety.

[0092] Standard tire pressure monitoring systems typically require an anomaly alarm to report within 10 minutes of an abnormal tire pressure reading. In this embodiment, the first preset time can be set to one minute; that is, if the tire pressure is detected to be higher than a preset threshold for one consecutive minute, it is determined that the tire is experiencing a slow leak, and the alarm device is activated to sound an alarm. In this embodiment, the preset threshold is calibrated before the vehicle leaves the factory.

[0093] In one embodiment of this application, when it is determined that there is a slow leak in the tire, the alarm device is controlled to issue an alarm.

[0094] In this embodiment of the application, when a slow air leak is detected in the tire, an alarm can be issued to remind the driver that the vehicle is leaking air slowly, which greatly avoids accidents and improves driving safety.

[0095] An example is a suspension control method, the steps of which include: S101. Obtain tire ground contact status image; S102. Preprocess the tire contact state image to obtain a smooth image; S103. Perform image segmentation on the smoothed image according to a set threshold to obtain the image contour; S104. The image contour is filtered and extracted to obtain the grounding contour; S105. Fit the grounding profile to obtain the major and minor axis parameters of the ellipse; S106. Substitute the major and minor axis parameters of the ellipse into the deformation ratio calculation formula to calculate the deformation ratio; S107. Using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient and rubber deformation attenuation coefficient as input parameters, and current tire pressure as output, construct a tire pressure calculation model; S108. Determine whether the number of passengers is less than the first set number, in order to calibrate the parameters of the tire pressure calculation model; S109. When the number of passengers is less than the first set number, the standard tire pressure is calibrated to the average value of the unloaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average value of the unloaded deformation ratio of the set number of passengers. S110. When the number of passengers is greater than or equal to the first preset number, determine whether the number of passengers is less than or equal to the second preset number; S111. When the number of passengers is less than or equal to the second set number, the standard tire pressure is calibrated to the average half-load tire pressure of the set number collected, and the reference deformation ratio is calibrated to the average half-load deformation ratio of the set number collected. S112. When the number of passengers is greater than the second set number, the standard tire pressure is calibrated to the average value of the full-load tire pressure of the set number collected, and the reference deformation ratio is calibrated to the average value of the full-load deformation ratio of the set number collected. S113. Obtain the current temperature to calibrate the parameters of the tire pressure calculation model; S114. Based on the current temperature and the set temperature compensation value, the rubber deformation attenuation coefficient is obtained by fitting through bench experiments. S115. Obtain the current road surface condition to calibrate the parameters of the tire pressure calculation model; S116. Determine the deformation ratio correction coefficient based on the road surface condition; S117. Calculate the current tire pressure based on the deformation ratio using a calibrated tire pressure calculation model; S118. Determine whether the difference between the current tire pressure and the standard tire pressure is greater than the set threshold. S119. When the air pressure exceeds the set threshold for a first set time period, it is determined that the tire is leaking air slowly. S120. When it is determined that there is a slow leak in the tire, the alarm device is controlled to issue an alarm.

[0096] This application provides a tire pressure monitoring system suitable for vehicles. Figure 6 The diagram shown is a structural schematic of the tire pressure monitoring system.

[0097] The tire pressure monitoring system 100 includes: Acquisition module 101 is used to acquire tire ground contact status images; Image processing module 102, connected to acquisition module 101, is used to perform image processing on tire ground contact state image to obtain ground contact contour, fit the ground contact contour into an ellipse, and obtain the major axis and minor axis parameters of the ellipse. The calculation module 103, connected to the image processing module 102, is used to calculate the deformation ratio based on the major and minor axis parameters of the ellipse, and to calculate the current tire pressure based on the deformation ratio using a pre-built tire pressure calculation model. The judgment module 106 is connected to the calculation module 103. The judgment module 106 is set to determine whether there is a slow air leak in the tire based on the current tire pressure and the standard tire pressure.

[0098] In one embodiment of this application, see further details. Figure 6 The system also includes: The model building module 104 is connected to the calculation module 103 and is used to build a tire pressure calculation model with standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient and rubber deformation attenuation coefficient as input parameters and current tire pressure as output. The calibration module 105 is connected to the model building module 104 and the calculation module 103, and is used to calibrate the parameters of the tire pressure calculation model. Alarm device 108 is used to issue an alarm; The control module 107 is connected to the judgment module 106 and the alarm device 108. The control module 107 is configured to control the alarm device to issue an alarm when it is determined that there is a slow air leak in the tire.

[0099] In one embodiment of this application, the image processing module 102 preprocesses the tire ground contact state image to obtain a smooth image; the image processing module 102 performs image segmentation on the smooth image according to a set threshold to obtain an image contour; the image processing module 102 filters and extracts the image contour to obtain a ground contact contour.

[0100] In one embodiment of this application, the calculation module 103 calculates the deformation ratio using the ratio of the major axis to the minor axis of the ellipse.

[0101] In one embodiment of this application, when the number of passengers is less than a first set number, the calibration module 105 calibrates the standard tire pressure to the average value of the unloaded tire pressure of the set number collected, and calibrates the reference deformation ratio to the average value of the unloaded deformation ratio of the set number collected; when the number of passengers is less than or equal to a second set number, the calibration module 105 calibrates the standard tire pressure to the average value of the half-loaded tire pressure of the set number collected, and calibrates the reference deformation ratio to the average value of the half-loaded deformation ratio of the set number collected; when the number of passengers is greater than the second set number, the calibration module 103 calibrates the standard tire pressure to the average value of the fully loaded tire pressure of the set number collected, and calibrates the reference deformation ratio to the average value of the fully loaded deformation ratio of the set number collected; the calibration module 103 obtains the rubber deformation attenuation coefficient by fitting the current temperature and the set temperature compensation value through bench experiments; the calibration module 103 calibrates the deformation ratio correction coefficient according to the road surface condition.

[0102] In one embodiment of this application, the judgment module 106 is further configured to: determine whether the number of passengers is less than a first preset number; when the number of passengers is greater than or equal to the first preset number, determine whether the number of passengers is less than or equal to a second preset number; and determine whether the difference between the current tire pressure and the standard tire pressure is greater than a preset threshold.

[0103] In one embodiment of this application, the acquisition module 101 is further configured to acquire the current temperature and the current road surface condition.

[0104] In one embodiment of this application, when the time exceeds a set threshold for a first set time period, the judgment module 106 determines that the tire has a slow air leakage phenomenon.

[0105] This application also provides a computer program product, which includes computer program code. When the computer program code is run on a computer, it causes the computer to execute the tire pressure monitoring method described in the above embodiments. This computer program can be installed in a vehicle system.

[0106] This application also provides a computer-readable storage medium storing program code that is executed by one or more processors. When the program code runs on the processor, it causes a device including one or more processors to perform the tire pressure monitoring method described in the above embodiments. The processor running this computer-readable storage medium can be installed in a vehicle system.

[0107] It should be understood that when the modules or units described herein are implemented using software, they can be implemented in whole or in part as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0108] This application provides a chip system including a processor, or the chip system including a memory and a processor, for calling computer programs or computer instructions stored in the memory to cause the processor to execute the tire pressure monitoring method described in the above embodiments. The chip system can be a single chip or a chip module composed of multiple chips. This chip system can be installed in a vehicle system.

[0109] This application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the electronic device implements the tire pressure monitoring method described in the above embodiments. This electronic device can be installed in a vehicle system.

[0110] This application provides a vehicle.

[0111] For example, see Figure 7 The vehicle 200 includes a memory 201, a processor 202, and a computer program 203 stored in the memory 201 and executable on the processor 202. When the processor 202 executes the computer program 203, it enables the processor 202 to implement the tire pressure monitoring method described in the above embodiments.

[0112] For example, the vehicle 200 may include an acquisition module, an image processing module, a calculation module, and a judgment module, which may be integrated into a processor.

[0113] The acquisition module is used to acquire images of the tire's ground contact status; The image processing module is connected to the acquisition module and is used to perform image processing on the tire ground contact state image to obtain the ground contact contour, fit the ground contact contour into an ellipse, and obtain the major axis and minor axis parameters of the ellipse. The calculation module is connected to the image processing module and is used to calculate the deformation ratio based on the major and minor axis parameters of the ellipse, and to calculate the current tire pressure based on the deformation ratio using a pre-built tire pressure calculation model. The judgment module is connected to the calculation module, and the judgment module is set to determine whether there is a slow air leak in the tire based on the current tire pressure and the standard tire pressure.

[0114] Those skilled in the art will recognize that the modules, units, and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0115] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be covered. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A tire pressure monitoring method, characterized in that, Applied to vehicles, the method includes: Acquire images of the tire's contact patch status; Image processing is performed on the tire ground contact image to obtain the ground contact profile. The ground contact profile is then fitted into an ellipse to obtain the major and minor axis parameters of the ellipse. The deformation ratio is calculated based on the major and minor axis parameters of the ellipse. The current tire pressure is calculated based on the deformation ratio using a pre-built tire pressure calculation model; Determine if there is a slow leak in the tire based on the current tire pressure and the standard tire pressure.

2. The tire pressure monitoring method according to claim 1, characterized in that, The method for obtaining the ground contact profile by image processing of tire ground contact state images is as follows: Preprocess the tire contact image to obtain a smooth image; The smoothed image is segmented according to a set threshold to obtain the image contour; The image contours are filtered and extracted to obtain the grounding contours.

3. The tire pressure monitoring method according to claim 1, characterized in that, The method for calculating the deformation ratio is as follows: the deformation ratio is obtained by using the ratio of the major axis to the minor axis of the ellipse.

4. The tire pressure monitoring method according to claim 1, characterized in that, The method for constructing the tire pressure calculation model is as follows: using standard tire pressure, reference deformation ratio, deformation ratio, deformation ratio correction coefficient, and rubber deformation attenuation coefficient as input parameters, and using the current tire pressure as the output, the tire pressure calculation model is constructed.

5. The tire pressure monitoring method according to claim 4, characterized in that, The method for calibrating the parameters of the tire pressure calculation model is as follows: Determine if the number of passengers is less than a first preset number; When the number of passengers is less than the first set number, the standard tire pressure is calibrated to the average value of the unloaded tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average value of the unloaded deformation ratio of the set number of passengers; when the number of passengers is greater than or equal to the first set number, it is determined whether the number of passengers is less than or equal to the second set number. When the number of passengers is less than or equal to the second set number, the standard tire pressure is calibrated to the average half-load tire pressure of the set number, and the reference deformation ratio is calibrated to the average half-load deformation ratio of the set number. When the number of passengers exceeds the second set number, the standard tire pressure is calibrated to the average value of the full-load tire pressure of the set number of passengers, and the reference deformation ratio is calibrated to the average value of the full-load deformation ratio of the set number of passengers.

6. The tire pressure monitoring method according to claim 4, characterized in that, The method for calibrating the parameters of the tire pressure calculation model is as follows: Get the current temperature; Based on the current temperature and the set temperature compensation value, the rubber deformation attenuation coefficient is obtained through bench testing.

7. The tire pressure monitoring method according to claim 4, characterized in that, The method for calibrating the parameters of the tire pressure calculation model is as follows: Get the current road surface status; The deformation ratio correction factor is determined based on the road surface condition.

8. A tire pressure monitoring system, characterized in that, Applied to vehicles, including: The acquisition module is used to acquire images of the tire's ground contact status. An image processing module, connected to the acquisition module, is used to perform image processing on the tire ground contact state image to obtain a ground contact contour, fit the ground contact contour into an ellipse, and obtain the major axis and minor axis parameters of the ellipse. The calculation module, connected to the image processing module, is used to calculate the deformation ratio based on the major and minor axis parameters of the ellipse, and to calculate the current tire pressure based on the deformation ratio using a pre-built tire pressure calculation model. The judgment module is connected to the calculation module, and the judgment module is set to determine whether there is a slow air leak in the tire based on the current tire pressure and the standard tire pressure.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program code that is executed by one or more processors, and when the program code is run on the processor, causes a device including the one or more processors to perform the tire pressure monitoring method as described in any one of claims 1 to 7.

10. A vehicle, characterized in that, The vehicle includes the tire pressure monitoring system as described in claim 8, or the computer-readable storage medium as described in claim 9.

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