Method and device for determining brake position of vehicle brake

Abstract

The present application relates to a method and device for determining the braking position of a vehicle brake; the method includes obtaining current data of the brake drive motor of the current vehicle within a preset time period; determining the DC component and AC component corresponding to the current sub-data in at least one mechanical cycle of the drive motor based on the current data; determining the target cycle of the current sub-data based on the AC component and the mechanical cycle; extracting a data group of the DC component in the target cycle, processing the data group to obtain a slope value, and processing the slope value to obtain the clamping force of the brake; when the clamping force is greater than a preset threshold, obtaining the piston position associated with the brake, and determining the target braking position of the brake based on the piston position and a preset brake trigger interval; determining the target braking position of the brake by processing the current data of the brake drive motor without adding additional sensors.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a method and device for determining the braking position of a vehicle brake. Background Art

[0002] In the related art, for the braking systems of low-end, flat, low-speed four-wheel electric vehicles, there are technical solutions that use low-cost window ripple motors to achieve wheel-free mechanical braking. While this economical solution offers a relatively low initial investment, it suffers from several deficiencies in accurately detecting and controlling braking force in real time. First, traditional braking force sensors are prone to performance instability under extreme climate conditions (such as high or low temperatures or humid environments), which can cause sensor signal distortion and affect the accurate response of the braking system. Second, when a sensor fails, the system often lacks effective fault diagnosis and early warning mechanisms, increasing vehicle safety risks. In particular, in emergency braking situations, inaccurate braking force can lead to increased braking distance or uneven braking performance, which can, in serious cases, cause traffic accidents. Furthermore, because it relies on single sensor data, this system lacks adaptability and flexibility in complex or changing driving environments, making it difficult to meet the high accuracy and reliability requirements of autonomous driving technology for braking systems. Therefore, this traditional braking force detection method is clearly unable to meet the current development needs of smart electric vehicles in terms of ensuring vehicle safety and improving autonomous driving performance. Summary of the Invention

[0003] Based on this, it is necessary to provide a method and device for determining the braking position of a vehicle brake that can improve the accuracy and reliability of the braking system in order to address the above technical problems.

[0004] In a first aspect, the present application provides a method for determining a brake position of a vehicle brake, comprising:

[0005] Obtaining current data of a drive motor of a brake of the current vehicle within a preset time period;

[0006] determining a DC component and an AC component corresponding to the current sub-data in at least one mechanical cycle of the drive motor based on the current data;

[0007] determining a target period associated with the current sub-data based on the AC component and the mechanical period;

[0008] extracting a data set of the DC component in the target cycle, processing the data set to obtain a corresponding slope value, and processing the slope value to obtain a clamping force of the brake;

[0009] When the clamping force is greater than a preset threshold, a piston position associated with the brake is acquired, and a target braking position of the brake is determined based on the piston position and a preset brake triggering distance.

[0010] In one embodiment, before determining the target braking position of the brake, the method further includes:

[0011] When the clamping force is greater than a preset threshold, obtaining the current wheel speed of the vehicle and the corresponding wheel speed at the previous moment;

[0012] Determining the target braking position of the brake includes:

[0013] determining a candidate brake position of the brake based on the piston position and a preset brake triggering distance;

[0014] In a case where the current wheel speed is less than the wheel speed at the previous moment, the to-be-selected braking position is determined as the target braking position of the brake.

[0015] In one embodiment, before determining the target braking position of the brake, the method further includes:

[0016] When the clamping force is greater than a preset threshold, obtaining the current wheel acceleration of the vehicle and the corresponding wheel acceleration at the previous moment;

[0017] Determining the target braking position of the brake includes:

[0018] determining a candidate brake position of the brake based on the piston position and a preset brake triggering distance;

[0019] In a case where the current wheel acceleration is less than the wheel acceleration at the previous moment, the to-be-selected braking position is determined as the target braking position of the brake.

[0020] In one embodiment, after determining the candidate braking position of the brake based on the piston position and the preset brake triggering distance, the method further includes:

[0021] When it is determined that the selected braking position is not the target braking position of the brake, current data of the driving motor of the brake of the current vehicle within the next preset time period is obtained to determine the target braking position of the brake corresponding to the updated current data.

[0022] In one embodiment, determining the target period associated with the current sub-data based on the AC component and the mechanical period includes:

[0023] Acquire a signal waveform corresponding to at least one of the mechanical cycles based on the AC component, and determine a first cycle of the signal waveform;

[0024] Acquire an autocorrelation function of the AC component at at least two time delays based on the AC component, and determine a corresponding second period based on the at least two autocorrelation functions;

[0025] If the difference between the second period and the first period is less than or equal to a preset difference, determining the first period as a candidate period associated with the current sub-data;

[0026] A target period including the to-be-selected period is acquired based on the to-be-selected period.

[0027] In one embodiment, determining the corresponding second period based on at least two of the autocorrelation functions includes:

[0028] A plurality of corresponding sub-periods are determined based on at least two of the autocorrelation functions, and a second period corresponding to at least two of the autocorrelation functions is determined based on a minimum value of differences between the sub-periods.

[0029] In one embodiment, determining the DC component and AC component corresponding to the current data in at least one mechanical cycle of the drive motor based on the current data includes:

[0030] processing the current data based on a time averaging method to determine a DC component corresponding to the current data in at least one mechanical cycle of the drive motor;

[0031] The current data corresponding to the DC component and a difference between the DC component are acquired, and an AC component corresponding to the DC component is determined based on the difference.

[0032] In one embodiment, processing the data set to obtain the corresponding slope value includes:

[0033] Processing the data set to obtain a plurality of corresponding time points and a current value of the DC component at each of the time points; and obtaining a time average of the plurality of time points and a current average of the plurality of current values;

[0034] A slope value corresponding to the data set is determined based on the multiple time points, the multiple current values, the time average value, and the current average value.

[0035] In one embodiment, processing the slope value to obtain the brake clamping force includes:

[0036] Determining, based on a first time point, cumulative values of a plurality of second time points before the first time point, and a slope value at the first time point; wherein the first time point is a current time point determined based on the plurality of time points;

[0037] determining increments corresponding to the slope values between a plurality of second time points before the first time point and the first time point;

[0038] The slope value is continuously accumulated based on the accumulated value, the increment, and a preset error correction term corresponding to the first time point to obtain the clamping force of the brake.

[0039] In a second aspect, the present application further provides a device for determining a braking position of a vehicle brake, comprising:

[0040] A data acquisition module, used to acquire current data of a drive motor of a brake of the current vehicle within a preset time period;

[0041] an AC / DC separation module, configured to determine a DC component and an AC component corresponding to current sub-data in at least one mechanical cycle of the drive motor based on the current data;

[0042] a period determination module, configured to determine a target period associated with the current sub-data based on the AC component and the mechanical period;

[0043] a data processing module, configured to extract a data set of the DC component in the target cycle, process the data set to obtain a corresponding slope value, and process the slope value to obtain a clamping force of the brake;

[0044] The target braking position determination module is used to obtain the piston position associated with the brake when the clamping force is greater than a preset threshold, and determine the target braking position of the brake based on the piston position and a preset brake triggering distance.

[0045] The above-mentioned method and apparatus for determining the braking position of a vehicle brake provided by the present application obtains current data of a driving motor of the current vehicle within a preset time period; determines the DC component and AC component corresponding to the current sub-data in at least one mechanical cycle of the driving motor based on the current data; determines a target cycle associated with the current sub-data based on the AC component and the mechanical cycle; extracts a data set of the DC component in the target cycle, processes the data set to obtain a corresponding slope value, and processes the slope value to obtain a brake clamping force; and when the clamping force is greater than a preset threshold, obtains a piston position associated with the brake, and determines the target braking position of the brake based on the piston position and a preset brake triggering interval. It can be seen that the present application obtains current data of the driving motor of the vehicle brake and processes the current data to determine the target braking position of the brake, that is, accurately identify the position where the brake is tightened. The present application determines the target braking position of the brake without adding additional sensors to the brake and avoids inaccuracies in the identified target braking position due to interference from factors such as climatic conditions and ambient temperature. The target braking position of the brake identified by this method is conducive to providing more precise braking control for smart cars and improving vehicle safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 1 is a flow chart of a method for determining a brake position of a vehicle brake in one embodiment;

[0048] Figure 2 is a waveform diagram of an AC component in one embodiment;

[0049] Figure 3 A schematic diagram showing the relationship between the position and pressure of a brake component in one embodiment;

[0050] Figure 4 is a flow chart of a method for determining a brake position of a vehicle brake in another embodiment;

[0051] Figure 5 is a structural block diagram of a device for determining a brake position of a vehicle brake in one embodiment;

[0052] Figure 6 This is a diagram of the internal structure of a vehicle-side control device in one embodiment. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0054] The method for determining the brake position of a vehicle brake provided in an embodiment of the present application can be applied to a smart car, an external device connected to a smart car, or a server connected to at least one of the smart car and the external device, wherein the smart car can communicate with the external device or server via a network, and the external device can communicate with the server via a network. The external device can be, but is not limited to, various personal computers, laptops, smartphones, and tablet computers. The server can be implemented as a standalone server or a server cluster consisting of multiple servers.

[0055] Figure 1 FIG. 1 is a flow chart of a method for determining a brake position of a vehicle brake in one embodiment. In an exemplary embodiment, as shown in FIG. Figure 1 As shown, a method for determining the braking position of a vehicle brake is provided, and the method is described by taking the application of the method to a smart car as an example, including the following steps 101 to 105. Among them:

[0056] Step 101 : obtaining current data of a driving motor of a brake of a current vehicle within a preset time period.

[0057] Specifically, by executing step 101 to collect the current data of the driving motor of the vehicle's brake, the current data of the driving motor within a preset time period can be selected for collection based on demand. The current data here is the current value corresponding to the driving motor when it is working.

[0058] The current data may be monitored and collected in real time through a drive-by-wire chassis angle controller in the vehicle.

[0059] Step 102 : Determine a DC component and an AC component corresponding to the current sub-data in at least one mechanical cycle of the drive motor based on the current data.

[0060] Specifically, by executing step 102, current sub-data is extracted from the current data obtained in step 101, and the current sub-data is specifically determined based on the sub-data in the current data corresponding to at least one mechanical cycle of the driving motor; then, the extracted current sub-data is separated from AC and DC to obtain DC component information and AC component information associated with the current sub-data; that is, in the process of performing AC and DC separation on the current data provided by the present application, it can be selected to perform AC and DC separation processing on the current data (that is, current sub-data) corresponding to one mechanical cycle or multiple mechanical cycles of the driving motor. By taking the current data of an integer number of mechanical cycles, the signal waveform corresponding to the processed current data can be made complete, thereby reducing errors, which is conducive to improving the calculation accuracy of the obtained DC component.

[0061] Step 103 : determining a target period associated with the current sub-data based on the AC component and the mechanical period.

[0062] Specifically, by executing step 103, a corresponding waveform signal diagram is generated based on the obtained AC component and DC component, and based on one or more waveform periods in the signal waveform diagram including the AC component and the DC component, combined with the mechanical period, the target period corresponding to the current sub-data is determined; wherein, the waveform period is determined based on the signal waveform of the AC component.

[0063] Step 104 : extracting a data set of a DC component in a target cycle, processing the data set to obtain a corresponding slope value, and processing the slope value to obtain a clamping force of the brake.

[0064] Specifically, step 104 is executed to extract data from the waveform of the DC component corresponding to the target period in the signal waveform diagram of the AC component and the DC component to form a data group, and then the data group is processed to obtain the slope value at the corresponding detection point; then, the slope that is not related to the required physical characteristics (such as the brake clamping force) is eliminated, and the slope value is processed to eliminate errors to obtain the clamping force of the brake.

[0065] Step 105 : When the clamping force is greater than a preset threshold, a piston position associated with the brake is obtained, and a target braking position of the brake is determined based on the piston position and a preset brake triggering distance.

[0066] Specifically, step 105 is executed. In the process of continuously processing the data group to continuously obtain the clamping force of the brake, when the obtained clamping force is greater than a preset threshold value of the clamping force, the piston position of the piston associated with the brake is obtained, and the target braking position of the brake is determined based on the piston position and the preset brake trigger spacing; wherein the piston position can represent a first spacing distance of the piston toward the brake disc in the brake, and the braking position can represent a second spacing distance of the piston toward the brake disc in the brake when the brake pad in the brake contacts the brake, and the second spacing distance is greater than the first spacing distance.

[0067] It needs to be explained that the positional relationship between the piston and the brake pad and brake disc in the brake can be that along an extension direction, the brake pad is located between the piston and the brake disc, and the piston can be used to push the brake pad into contact with the brake disc to achieve the braking function for the vehicle.

[0068] Among them, the clamping force is formed between the brake disc and the brake pad. The preset threshold value of the clamping force refers to the clamping force corresponding to when the brake pad and the brake disc are just in effective contact.

[0069] The method for determining the braking position of a vehicle brake provided by the present application comprises obtaining current data of a drive motor of the current vehicle within a preset time period; determining a DC component and an AC component corresponding to the current sub-data in at least one mechanical cycle of the drive motor based on the current data; determining a target cycle associated with the current sub-data based on the AC component and the mechanical cycle; extracting a data set of the DC component in the target cycle, processing the data set to obtain a corresponding slope value, and processing the slope value to obtain a brake clamping force; obtaining a piston position associated with the brake when the clamping force is greater than a preset threshold, and determining a target braking position of the brake based on the piston position and a preset brake triggering interval. It can be seen that the present application obtains current data of the drive motor of the vehicle brake and processes the current data to determine the target braking position of the brake, that is, accurately identify the position where the brake is tightened; the present application does not require additional sensors for the brake and does not cause inaccuracy in the identified target braking position due to interference from factors such as climatic conditions and ambient temperature; the target braking position of the brake identified by the present method is conducive to providing more precise braking control for smart cars and improving vehicle safety.

[0070] Please continue to refer to Figure 1 In an exemplary embodiment, before determining the target braking position of the brake in step 105, the method further includes:

[0071] When the clamping force is greater than a preset threshold, obtaining the current wheel speed of the vehicle and the corresponding wheel speed at the previous moment;

[0072] The step 105 of determining the target braking position of the brake includes:

[0073] determining a candidate braking position of the brake based on the piston position and a preset brake activation distance;

[0074] When the current wheel speed is less than the wheel speed at the previous moment, the to-be-selected braking position is determined as the target braking position of the brake.

[0075] Specifically, for determining the target braking position, the present application provides an optional determination method, which is that before executing the step of determining the target braking position of the brake in step 105, the current wheel speed of the vehicle and the wheel speed at the previous moment corresponding to the current wheel speed can be first obtained when the clamping force is monitored to be greater than the preset threshold; then, based on the obtained piston position and the preset brake trigger interval, the braking position of the brake is determined to be the selected braking position, not the target braking position; then, the current wheel speed and the wheel speed at the previous moment are compared. When the current wheel speed is less than the wheel speed at the previous moment, it means that the braking force generated by the brake pads and brake discs in the brake has taken effect, causing the vehicle speed to slow down and achieve the braking effect. At this time, it can be determined that the previously obtained selected braking position is the target braking position of the brake.

[0076] This method combines wheel speed changes to determine the accuracy of the selected braking position. By analyzing wheel speed changes, it can be confirmed whether the moment the brake pad and disc are activated is the moment when the clamping force begins to apply. This comprehensive determination method can further provide more reliable monitoring of the braking force activation moment, thereby ensuring the safety and stability of the braking system.

[0077] If the current wheel speed is greater than or equal to the previous wheel speed, the target braking position of the brake can be re-determined based on the preset conditions to improve the accuracy of the determined target braking position. Alternatively, the data from this monitoring process can be discarded and the method for determining the next braking position can be re-executed.

[0078] Among them, the wheel speed can also be monitored and collected in real time based on the wire-controlled chassis angle controller in the vehicle.

[0079] This application utilizes the current sensor information of the drive motor and, without adding additional (mechanical) sensors, can accurately estimate the moment when the brake is tightened and obtain information on the target braking position of the brake under the influence of different uncertain factors such as temperature and voltage; based on the identified target braking position of the brake, it is beneficial to provide smart cars with more precise braking control during vehicle driving, thereby improving vehicle safety.

[0080] Please continue to refer to Figure 1 In an exemplary embodiment, before determining the target braking position of the brake in step 105, the method further includes:

[0081] When the clamping force is greater than a preset threshold, obtaining the current wheel acceleration of the vehicle and the corresponding wheel acceleration at the previous moment;

[0082] The step 105 of determining the target braking position of the brake includes:

[0083] determining a candidate braking position of the brake based on the piston position and a preset brake activation distance;

[0084] When the current wheel acceleration is less than the wheel acceleration at the previous moment, the to-be-selected braking position is determined as the target braking position of the brake.

[0085] Specifically, for determining the target braking position, the present application provides an optional determination method, which is that before executing the step of determining the target braking position of the brake in step 105, when monitoring that the clamping force is greater than a preset threshold, the current wheel acceleration of the vehicle and the wheel acceleration at the previous moment corresponding to the current wheel acceleration can be first obtained; then, based on the obtained piston position and the preset brake trigger interval, the braking position of the brake is determined to be a selected braking position, not a target braking position; then, the current wheel acceleration and the wheel acceleration at the previous moment are compared. When the current wheel acceleration is less than the wheel acceleration at the previous moment, it means that the braking force generated by the brake pads and brake discs in the brake has taken effect, causing the acceleration of the vehicle to decrease. Even if the vehicle is still accelerating, the reduction in vehicle acceleration indicates that the braking effect has been achieved. At this time, it can be determined that the previously obtained selected braking position is the target braking position of the brake.

[0086] This method combines acceleration changes to determine the accuracy of the selected braking position. By analyzing acceleration changes, it can confirm whether the moment the brake pad and disc are activated is actually the moment when the clamping force begins to apply. This comprehensive determination method can further provide more reliable monitoring of the braking force activation moment, thereby ensuring the safety and stability of the braking system.

[0087] If the current wheel acceleration is greater than or equal to the previous wheel acceleration, the target braking position of the brake can be re-determined based on the preset value to improve the accuracy of the determined target braking position. Alternatively, the data from this monitoring process can be discarded and the method for determining the braking position can be re-executed for the next round.

[0088] Among them, acceleration can also be monitored and collected in real time based on the wire-controlled chassis angle controller in the vehicle.

[0089] Please continue to refer to Figure 1 In an exemplary embodiment, after determining the candidate braking position of the brake based on the piston position and the preset brake triggering distance, the method further includes:

[0090] When it is determined that the selected braking position is not the target braking position of the brake, current data of the driving motor of the brake of the current vehicle within the next preset time period is obtained to determine the target braking position of the brake corresponding to the updated current data.

[0091] That is, when it is determined that the above-mentioned candidate braking position is not the target braking position, that is, the wheel speed at the current moment may not have changed or has increased compared with the previous moment, or the acceleration at the current moment may not have changed or has increased compared with the previous moment, at this time, the data of this monitoring processing can be discarded and the method for determining the next round of braking position can be re-executed; that is, the current data of the driving motor of the brake of the current vehicle within the next preset time period can be selected to determine the target braking position of the brake corresponding to the updated acquired current data based on the above-mentioned steps 101-step 105.

[0092] Please continue to refer to Figure 1 In an exemplary embodiment, the step 103 of determining the target cycle associated with the current sub-data based on the AC component and the mechanical cycle includes steps 131 to 134, wherein:

[0093] Step 131: obtaining a signal waveform corresponding to at least one mechanical cycle based on the AC component, and determining a first cycle of the signal waveform;

[0094] Step 132: obtaining an autocorrelation function of the AC component at at least two time delays, and determining a corresponding second period based on the at least two autocorrelation functions;

[0095] Step 133: if the difference between the second period and the first period is less than or equal to a preset difference, determine the first period as a candidate period associated with the current sub-data;

[0096] Step 134 : acquiring a target period including the period to be selected based on the period to be selected.

[0097] Specifically, the present application provides a specific implementation step for step 103, which includes executing step 131 to obtain the position information of the current ripple peak corresponding to the AC component current based on the AC component, and then obtaining a signal waveform corresponding to at least one mechanical cycle based on the peak position information and the AC component current information. The signal waveform is also the AC component signal waveform, and the period of the AC component signal waveform is determined to be the first period. Then, step 132 is executed to perform a secondary determination on the accuracy of the first period obtained by executing step 131. The periodicity of the signal relative to a single period can be identified by analyzing the AC component data and using autocorrelation instead of Fourier transform. Specifically, the autocorrelation function of the AC component under at least two time delays is obtained based on the AC component, and the corresponding second period is determined based on the at least two autocorrelation functions. Then, step 133 is executed to compare the first period with the second period. If the difference between the second period and the first period is less than or equal to a preset difference, it indicates that the first period and the second period are the same, or the difference between the first period and the second period is very small. In this case, the first period can be determined as the candidate period associated with the current sub-data. Then, step 134 is executed to determine a target cycle corresponding to the candidate cycle based on the candidate cycle and the mechanical cycle, wherein the cycle length of the target cycle is greater than the cycle length of the candidate cycle, and the target cycle includes the corresponding candidate cycle.

[0098] Therefore, with respect to the content of determining the corresponding second period based on at least two autocorrelation functions performed in the above-mentioned step 132, the present application provides an optional implementation method, which is to determine the corresponding multiple sub-periods based on at least two autocorrelation functions, and determine the second period corresponding to at least two autocorrelation functions based on the minimum value of the difference between each sub-period, that is, the peak is determined by selecting the peak value with the smallest error between each sub-period, and the corresponding second period is determined, which is conducive to improving the accuracy of the obtained second period.

[0099] It should be added that the present application provides an embodiment of determining the peak value of the motor current, specifically, based on the AC component current Through feature determination, the position information of the current ripple peak is obtained. Figure 2 FIG. 1 is a waveform diagram of an AC component in an embodiment. In this step, as shown in FIG. Figure 2 As shown, when the current There is a highest point b in the circuit, and its current value is , and a point c appears with the current value The current difference at this time is , The value is greater than 20% of the ripple amplitude. And the time distance before point b is ( The current at point a on the Less than current At this point, it is judged as a peak.

[0100] The rationality of the peak can then be evaluated based on the autocorrelation, specifically based on the correlation function Implementation, where Indicates signal In time delay The autocorrelation function under is the value of the AC signal, It is the total duration of the signal. Here, it is taken as the duration of multiple ripple numbers within at least one mechanical cycle according to the speed of the drive motor. It's a time delay.

[0101] The correlation at different time delays is calculated by averaging the product of the signal and itself at different time points to obtain the autocorrelation. This allows us to obtain the period value of a single cycle of waveform data.

[0102] It should be added that in the process of determining the candidate period, the rationality of the peak can be judged based on the period value; usually only one peak appears in one period. If other peaks appear due to interference caused by harmonic factors or interference from other power supply parts, the distance between the peaks can be calculated and the peak value with the smallest error and movement trend can be selected as the correct peak.

[0103] Please continue to refer to Figure 1 In an exemplary embodiment, the step 102 of determining the DC component and AC component corresponding to the current data in at least one mechanical cycle of the drive motor based on the current data includes:

[0104] processing the current data based on a time averaging method to determine a DC component corresponding to the current data in at least one mechanical cycle of the drive motor;

[0105] Current data corresponding to the DC component and a difference between the DC component are obtained, and an AC component corresponding to the DC component is determined based on the difference.

[0106] Specifically, for the content executed in the above-mentioned step 102, the present application provides an optional implementation method, which is, first, processing the current data based on the time averaging method to determine the DC component corresponding to the current data in at least one mechanical cycle of the driving motor; and then, based on the difference between the calculated current data and the DC component, obtaining the AC component, specifically, determining the AC component corresponding to the DC component based on the difference between the calculated current data and the DC component corresponding to the current data.

[0107] It should also be added that when current data within a preset time period is collected, useless high-frequency components in the current data can be removed through low-pass filtering, and AC and DC separation can be performed to obtain information on each component.

[0108] Here, a specific optional implementation method is provided, which is to use the time averaging method to separate the DC component, and then obtain the AC component by subtracting the DC component from the original signal. Specifically:

[0109] The DC component can be obtained by time averaging the signal. DC The optional calculation formula is After obtaining the DC component, this value can be subtracted from the original signal of the current data to obtain the AC component. The AC component i AC The optional calculation formula is .

[0110] in, It's time signal, is the time period of integration; T can be one or more mechanical cycles of the brake; ideally, The value should be a complete signal cycle or an integer multiple thereof to avoid the effects of phase differences. If the cycle is not a complete signal cycle, truncation may cause deviations in the calculated results, especially when the signal contains multiple frequency components. This also helps enhance the stability of the results. By taking an integer number of cycles, the waveform within the integration interval is complete, thus reducing errors and improving the accuracy of the DC component calculation.

[0111] Please continue to refer to Figure 1 In an exemplary embodiment, the step 104 of processing the data set to obtain the corresponding slope value may include:

[0112] Processing the data set to obtain corresponding multiple time points and the current value of the DC component at each time point; and obtaining a time average of the multiple time points and a current average of the multiple current values;

[0113] A slope value corresponding to the data set is determined based on a plurality of time points, a plurality of current values, a time average value, and a current average value.

[0114] Specifically, with respect to the content of processing the data group in step 104 to obtain the corresponding slope value, the present application provides an optional implementation method of first analyzing and processing the data group to obtain multiple time points corresponding to the data group, and the current value of the DC component at each time point, and obtaining the time average value corresponding to the multiple time points, and the current average value corresponding to the multiple current values, and then calculating the slope value corresponding to the data group based on the multiple time points, the multiple current values, the time average value and the current average value.

[0115] An optional embodiment is provided, in the current parameter of the acquired data set, the current slope value at the detection point is obtained by linear regression. The formula can be Calculate. Where: It is The value at a time point. It's in time The current value. All time points The average value of . All current values The average value of . It is the sum of the products of time and current value deviation, which reflects the coordinated changes between time and current. is the sum of squares of temporal deviations, which measures the variability of the temporal data itself.

[0116] Please continue to refer to Figure 1 In an exemplary embodiment, the step 104 of processing the slope value to obtain the brake clamping force may include:

[0117] Determine, based on the first time point, the cumulative values of multiple second time points before the first time point, and the slope value of the first time point; wherein the first time point is a current time point determined based on the multiple time points;

[0118] Determining increments corresponding to slope values between a plurality of second time points before the first time point and the first time point;

[0119] The slope value is continuously accumulated based on the accumulated value, the increment, and the preset error correction term corresponding to the first time point to obtain the clamping force of the brake.

[0120] Specifically, with respect to the content of processing the slope value in step 104 to obtain the clamping force of the brake, the present application provides an optional implementation method, which is to determine the cumulative values of multiple second time points before the first time point and the slope value of the first time point based on the first time point; and, determine the increment corresponding to the slope value from the multiple second time points before the first time point to the first time point; finally, based on the cumulative value, the increment and the preset error correction item corresponding to the first time point, the slope value is continuously accumulated to achieve the effect of eliminating the accumulated error, and then the clamping force of the brake is obtained.

[0121] Here is a supplementary embodiment: since other electrical characteristics are retained in the current data for other functional analysis, only the slope characteristics related to mechanics are extracted in the determination of the clamping force. For example, when the brake disc and brake pad are in instantaneous contact, the inherent stiffness of the transmission system corresponding to the brake drive motor is used as a reference, and the slopes beyond the mechanical and performance characteristics are filtered out. .

[0122] Provide a formula for continuously accumulating slope values: ;in, is the accumulated value; It means at time The cumulative value, which is calculated at the first time point The base value of It means from time arrive During this period, due to the slope The resulting increment; here It's in time The slope of is the time interval. The calculation of this item is essentially to estimate the contribution (i.e. area). It's in time The error correction term, that is, the preset error correction term mentioned above, is subtracted to correct any known data measurement inaccuracy or data error; wherein, this error can be determined according to the actual acquisition calibration.

[0123] The slope value corresponds to The value is used to evaluate whether the brake pad has been tightened in place and has reached the preset clamping force value. The clamping force value is the clamping force between the brake pad and the brake disc. The value exceeds the preset calibration threshold , which indicates that the brake pads have effectively contacted the brake disc and braking force can be applied. Figure 3 A schematic diagram of the relationship between the position and pressure of brake components in one embodiment, wherein the components include at least a brake disc and a brake pad. Figure 3, the position of the piston at this moment is , the corresponding brake disc is compressed to , that is, from the position just touching the brake disc Until the piston position corresponding to the clamping force is detected distance, It can be confirmed during calibration. So when the position of the clamping force is known In this case, the contact position of the brake disc can be obtained Since this method is highly robust and can accurately determine the clamping force, the threshold can be set lower, which not only reduces misjudgments but also effectively covers the problem of braking force fluctuations caused by uneven brake discs. This is the piston position described in step 105, where a discernible clamping force is present between the brake disc and the brake pad. This is the selected braking position described in step 105, that is, the position where the brake pad and the brake disc just come into contact. This is the preset brake triggering distance described in step 105 .

[0124] Figure 4 This is a flow chart of a method for determining the braking position of a vehicle brake in another embodiment. Figure 1 Reference Figure 4 The method shows a method for determining the braking position of a brake based on the above content of the present application. The vehicle brake can be a dry brake. Specifically, the method includes: step S1: real-time monitoring of the vehicle dry brake motor current parameters; step S2: processing the motor current parameters to achieve AC / DC separation; step S3: determining the peak value of the motor current; step S4: evaluating the rationality of the peak based on autocorrelation; step S5: obtaining N periodic current parameters, where N is a positive integer; step S6: calculating the current slope; step S7: continuous accumulation and cumulative error elimination; step S8: clamping state and compression stroke determination. The clamping state includes and , compression stroke includes .

[0125] The method for determining the braking position of a vehicle brake provided in the present application can effectively ignore the effects caused by constant deviation errors, periodicity and abnormal pulse interference. This high-precision clamping force determination allows the threshold to be set very low, effectively covering the jitter problem caused by uneven brake discs. At the same time, by combining the change in wheel speed to determine the starting moment of the clamping force, the response speed and accuracy of the braking system are further enhanced. This not only improves the reliability and safety of the braking system, but also provides a solid foundation for the implementation of autonomous driving technology. By precisely controlling the braking force, the driving stability of the vehicle in complex environments can be greatly improved, providing a safer and more comfortable driving experience for the driver and passengers. In addition, since no additional sensors are required, this method also helps to reduce the cost and complexity of the system, and is easier to be widely used in various models, which in turn helps to enhance the intelligence of smart cars.

[0126] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0127] Based on the same inventive concept, embodiments of the present application also provide a vehicle brake position determination device for implementing the aforementioned vehicle brake position determination method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more vehicle brake position determination device embodiments provided below can be found in the aforementioned vehicle brake position determination method, and will not be further elaborated here.

[0128] In an exemplary embodiment, Figure 5 This is a structural block diagram of a device for determining the braking position of a vehicle brake in one embodiment. Figure 1-Figure 4 Reference Figure 5 , provides a device 200 for determining the braking position of a vehicle brake, comprising: a data acquisition module 81, an AC / DC separation module 82, a cycle determination module 83, a data processing module 84, and a target braking position determination module 85, wherein:

[0129] The data acquisition module 81 is used to obtain the current data of the driving motor of the brake of the current vehicle within a preset time period;

[0130] an AC / DC separation module 82 for determining a DC component and an AC component corresponding to current sub-data in at least one mechanical cycle of the drive motor based on the current data;

[0131] a period determination module 83 for determining a target period associated with the current sub-data based on the AC component and the mechanical period;

[0132] a data processing module 84 for extracting a data set of a DC component in a target cycle, processing the data set to obtain a corresponding slope value, and processing the slope value to obtain a clamping force of the brake;

[0133] The target braking position determination module 85 is used to obtain the piston position associated with the brake when the clamping force is greater than a preset threshold, and determine the target braking position of the brake based on the piston position and a preset brake triggering distance.

[0134] Specifically, the data acquisition module 81 is used to collect the current data of the driving motor of the vehicle's brake. It can select to collect the current data of the driving motor within a preset time period based on demand. The current data here is the current value corresponding to the driving motor when it is working.

[0135] The AC / DC separation module 82 is used to extract current sub-data from the acquired current data, and the current sub-data is specifically determined based on the sub-data in the current data corresponding to at least one mechanical cycle of the drive motor; and then AC / DC separation is performed on the extracted current sub-data to obtain DC component information and AC component information associated with the current sub-data; that is, in the process of AC / DC separation of current data provided by the present application, it is possible to selectively perform AC / DC separation processing on the current data (i.e., current sub-data) corresponding to one mechanical cycle or multiple mechanical cycles of the drive motor. By taking the current data of an integer number of mechanical cycles, the signal waveform corresponding to the processed current data can be made complete, thereby reducing errors and facilitating improving the calculation accuracy of the obtained DC component.

[0136] The period determination module 83 is used to generate a corresponding waveform signal diagram based on the obtained AC component and DC component, and determine the target period corresponding to the current sub-data based on one or more waveform periods in the signal waveform diagram including the AC component and the DC component, combined with the mechanical period; wherein, the waveform period is determined based on the signal waveform of the AC component.

[0137] The data processing module 84 is used to extract data from the waveform of the DC component corresponding to the target period in the signal waveform diagrams of the AC component and the DC component to form a data group, and then process the data group to obtain the slope value at the corresponding detection point; further, eliminate the slope that is not related to the required physical characteristics (such as the brake clamping force), and obtain the brake clamping force by eliminating the error of the slope value.

[0138] The target braking position determination module 85 is used to obtain the piston position associated with the brake when the clamping force obtained is greater than a preset threshold value of the clamping force by continuously processing data groups to continuously obtain the clamping force of the brake, and determine the target braking position of the brake based on the piston position and the preset brake trigger spacing; wherein the piston position can represent a first spacing distance between the piston and the brake disc in the brake, and the braking position can represent a second spacing distance between the piston and the brake disc in the brake when the brake pad in the brake contacts the brake, and the second spacing distance is greater than the first spacing distance.

[0139] In an optional embodiment, before the target braking position determination module 85 is used to determine the target braking position of the brake, it also includes: calling the data acquisition module 81 to obtain the current wheel speed of the vehicle and the corresponding wheel speed at the previous moment when the clamping force is greater than a preset threshold; the target braking position determination module 85 is used to determine the target braking position of the brake, including: determining the brake's candidate braking position based on the piston position and the preset brake trigger spacing; when the current wheel speed is less than the wheel speed at the previous moment, determining the candidate braking position as the target braking position of the brake.

[0140] In an optional embodiment, before the target braking position determination module 85 is used to determine the target braking position of the brake, it also includes: calling the data acquisition module 81 to obtain the current wheel acceleration of the vehicle and the corresponding wheel acceleration at the previous moment when the clamping force is greater than a preset threshold; the target braking position determination module 85 is used to determine the target braking position of the brake, including: determining the brake's candidate braking position based on the piston position and the preset brake trigger spacing; when the current wheel acceleration is less than the wheel acceleration at the previous moment, determining the candidate braking position as the target braking position of the brake.

[0141] In an optional embodiment, after the target braking position determination module 85 is used to determine the candidate braking position of the brake based on the piston position and the preset brake trigger distance, it also includes: when it is determined that the candidate braking position is not the target braking position of the brake, obtaining the current data of the driving motor of the brake of the current vehicle within the next preset time period to determine the target braking position of the brake corresponding to the updated acquired current data.

[0142] In an optional embodiment, the period determination module 83 is used to determine a target period associated with the current sub-data based on the AC component and the mechanical period, including: obtaining a signal waveform corresponding to at least one mechanical period based on the AC component, and determining a first period of the signal waveform; obtaining its autocorrelation function under at least two time delays based on the AC component, and determining a corresponding second period based on at least two autocorrelation functions; when the difference between the second period and the first period is less than or equal to a preset difference, determining the first period as a candidate period associated with the current sub-data; and obtaining a target period including the candidate period based on the candidate period.

[0143] In an optional embodiment, the period determination module 83 is used to determine the corresponding second period based on at least two autocorrelation functions, including: determining the corresponding multiple sub-periods based on the at least two autocorrelation functions, and determining the second period corresponding to the at least two autocorrelation functions based on the minimum value of the difference between the sub-periods.

[0144] In an optional embodiment, the AC / DC separation module 82 is used to determine the DC component and AC component corresponding to the current data in at least one mechanical cycle of the driving motor based on the current data, including: processing the current data based on a time averaging method to determine the DC component corresponding to the current data in at least one mechanical cycle of the driving motor; obtaining the difference between the current data corresponding to the DC component and the DC component, and determining the AC component corresponding to the DC component based on the difference.

[0145] In an optional embodiment, the data processing module 84 is used to process the data group to obtain a corresponding slope value, including: processing the data group to obtain corresponding multiple time points, and the current value of the DC component at each time point; and obtaining the time average value of the multiple time points, and the current average value of the multiple current values; determining the slope value corresponding to the data group based on the multiple time points, the multiple current values, the time average value and the current average value.

[0146] In an optional embodiment, the data processing module 84 is used to process the slope value to obtain the clamping force of the brake, including: determining the cumulative value of multiple second time points before the first time point based on the first time point, and the slope value of the first time point; wherein the first time point is a current time point determined based on multiple time points; determining the increment corresponding to the slope value from the multiple second time points before the first time point to the first time point; based on the cumulative value, the increment and the preset error correction item corresponding to the first time point, the slope value is continuously accumulated to obtain the clamping force of the brake.

[0147] Each module in the aforementioned apparatus for determining the braking position of a vehicle brake may be implemented in whole or in part via software, hardware, or a combination thereof. Each module may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in the computer device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0148] Figure 6 In an exemplary embodiment, a vehicle-side control device is provided. The internal structure diagram of the vehicle-side control device can be as follows: Figure 6 As shown. The vehicle-side control device includes a processor and a memory. The processor of the vehicle-side control device is used to provide computing and control capabilities. The memory of the vehicle-side control device includes a non-volatile storage medium that stores a computer program. When executed by the processor, the computer program implements a control method for upgrading vehicle functions.

[0149] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application, and does not constitute a limitation on the vehicle-end control device to which the scheme of the present application is applied. The specific vehicle-end control device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0150] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0151] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0152] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0153] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for determining the braking position of a vehicle brake, characterized in that: include: Obtaining current data of a drive motor of a brake of the current vehicle within a preset time period; processing the current data based on a time averaging method to determine a DC component corresponding to the current sub-data in at least one mechanical cycle of the drive motor; Obtaining a difference between the current sub-data corresponding to the DC component and the DC component, and determining an AC component corresponding to the DC component based on the difference; determining a target period associated with the current sub-data based on the AC component and the mechanical period; extracting a data set of the DC component in the target cycle, processing the data set to obtain a corresponding slope value, and processing the slope value to obtain a clamping force of the brake; When the clamping force is greater than a preset threshold, a piston position associated with the brake is acquired, and a target braking position of the brake is determined based on the piston position and a preset brake triggering distance.

2. The method according to claim 1, characterized in that Before determining the target braking position of the brake, the method further includes: When the clamping force is greater than a preset threshold, obtaining the current wheel speed of the vehicle and the corresponding wheel speed at the previous moment; Determining the target braking position of the brake includes: determining a candidate brake position of the brake based on the piston position and a preset brake triggering distance; In a case where the current wheel speed is less than the wheel speed at the previous moment, the to-be-selected braking position is determined as the target braking position of the brake.

3. The method according to claim 1, characterized in that Before determining the target braking position of the brake, the method further includes: When the clamping force is greater than a preset threshold, obtaining the current wheel acceleration of the vehicle and the corresponding wheel acceleration at the previous moment; Determining the target braking position of the brake includes: determining a candidate brake position of the brake based on the piston position and a preset brake triggering distance; In a case where the current wheel acceleration is less than the wheel acceleration at the previous moment, the to-be-selected braking position is determined as the target braking position of the brake.

4. The method according to claim 2 or 3, characterized in that After determining the candidate braking position of the brake based on the piston position and the preset brake triggering distance, the method further includes: When it is determined that the selected braking position is not the target braking position of the brake, current data of the driving motor of the brake of the current vehicle within the next preset time period is obtained to determine the target braking position of the brake corresponding to the updated current data.

5. The method according to claim 1, wherein The determining of a target period associated with the current sub-data based on the AC component and the mechanical period includes: Acquire a signal waveform corresponding to at least one of the mechanical cycles based on the AC component, and determine a first cycle of the signal waveform; Acquire an autocorrelation function of the AC component at at least two time delays based on the AC component, and determine a corresponding second period based on the at least two autocorrelation functions; If the difference between the second period and the first period is less than or equal to a preset difference, determining the first period as a candidate period associated with the current sub-data; A target period including the to-be-selected period is acquired based on the to-be-selected period.

6. The method according to claim 5, characterized in that The determining the corresponding second period based on at least two of the autocorrelation functions includes: A plurality of corresponding sub-periods are determined based on at least two of the autocorrelation functions, and a second period corresponding to at least two of the autocorrelation functions is determined based on a minimum value of differences between the sub-periods.

7. The method according to claim 1, characterized in that The processing of the data set to obtain a corresponding slope value comprises: Processing the data set to obtain a plurality of corresponding time points and a current value of the DC component at each of the time points; and obtaining a time average of the plurality of time points and a current average of the plurality of current values; A slope value corresponding to the data set is determined based on the multiple time points, the multiple current values, the time average value, and the current average value.

8. The method according to claim 7, characterized in that The processing of the slope value to obtain the clamping force of the brake comprises: Determining, based on a first time point, cumulative values of a plurality of second time points before the first time point, and a slope value at the first time point; wherein the first time point is a current time point determined based on the plurality of time points; determining increments corresponding to the slope values between a plurality of second time points before the first time point and the first time point; The slope value is continuously accumulated based on the accumulated value, the increment, and a preset error correction term corresponding to the first time point to obtain the clamping force of the brake.

9. A device for determining the braking position of a vehicle brake, characterized in that: include: A data acquisition module, used to acquire current data of a drive motor of a brake of the current vehicle within a preset time period; an AC / DC separation module, configured to process the current data based on a time averaging method to determine a DC component corresponding to the current sub-data in at least one mechanical cycle of the drive motor; Obtaining a difference between the current sub-data corresponding to the DC component and the DC component, and determining an AC component corresponding to the DC component based on the difference; a period determination module, configured to determine a target period associated with the current sub-data based on the AC component and the mechanical period; a data processing module, configured to extract a data set of the DC component in the target cycle, process the data set to obtain a corresponding slope value, and process the slope value to obtain a clamping force of the brake; The target braking position determination module is used to obtain the piston position associated with the brake when the clamping force is greater than a preset threshold, and determine the target braking position of the brake based on the piston position and a preset brake triggering distance.

10. A vehicle-side control device, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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