Method, system and equipment for testing return quantity of piston of floating type electronic mechanical brake caliper

Abstract

The invention discloses a floating type electronic mechanical brake caliper piston return quantity testing method, system and equipment, and the method comprises the steps: driving an electronic mechanical brake caliper to unload clamping force, and continuously recording a first voltage signal of a first displacement sensor, a second voltage signal of a second displacement sensor and a motor coding position of the electronic mechanical brake caliper; determining first displacement data according to the first voltage signal and the first temperature drift rate, determining second displacement data according to the second voltage signal and the second temperature drift rate, and calculating a piston real return curve of the electromechanical brake caliper according to the first displacement data and the second displacement data; and determining the return stabilization time and the average return speed according to the piston real return curve, determining the mechanical transmission chain back clearance according to the first displacement data and the motor coding position, and evaluating the control performance index according to the piston real return curve. The method improves the accuracy and reliability of the floating type electronic mechanical brake caliper piston return quantity test, and can be applied to the technical field of vehicle test.

Description

Technical Field

[0001] This invention relates to the field of vehicle testing technology, and in particular to a method, system and equipment for testing the piston return amount of a floating electromechanical brake caliper. Background Technology

[0002] The shift from measuring the return distance of traditional hydraulic brake calipers based on physical springback to measuring the return distance of electromechanical brake calipers (EMBs) presents technical challenges in practical engineering applications. Hydraulic brake caliper return distance relies primarily on the elasticity of the seals, making the measurement target relatively singular: precisely capturing this minute physical springback displacement. However, EMB return distance is driven and controlled by a motor, presenting a more complex situation. First, the control accuracy and response speed of the motor directly affect the return distance result. Inappropriate parameter tuning in the control algorithm (such as PID parameters) can easily lead to incomplete return or overshoot. Second, the mechanical transmission components of EMBs, such as gears and lead screws, have unavoidable manufacturing clearances (backlash). When the motor reverses to return, this clearance must be overcome, resulting in a deviation between the motor encoder reading and the actual piston position. Accurately identifying and compensating for this deviation is crucial for the measurement. Furthermore, EMBs are prone to heat generation during testing, and the motor torque characteristics and material dimensions change with temperature, posing challenges to the stability and repeatability of the measurement results. These factors mean that EMB return measurement is no longer a simple displacement reading problem, but a systematic problem that requires comprehensive consideration of multiple factors such as electrical control, mechanical and thermal management. Summary of the Invention

[0003] The purpose of this invention is to at least partially solve one of the technical problems existing in the prior art.

[0004] Therefore, one objective of this invention is to provide a method for testing the piston return amount of a floating electromechanical brake caliper, which improves the accuracy and reliability of testing the piston return amount of a floating electromechanical brake caliper.

[0005] Another objective of this invention is to provide a floating electromechanical brake caliper piston return measurement system.

[0006] To achieve the above-mentioned technical objectives, the technical solutions adopted in the embodiments of the present invention include: On one hand, embodiments of the present invention provide a method for testing the piston return amount of a floating electromechanical brake caliper, comprising the following steps: The electromechanical brake caliper is driven to work, so that the electromechanical brake caliper generates a preset clamping force and continues for a preset time before being unloaded to 0, thereby enabling the motor, transmission mechanism and brake disc of the electromechanical brake caliper to reach the preset working temperature and working state. The electromechanical brake caliper is driven to work, so that the electromechanical brake caliper generates the preset clamping force, and the first baseline data of the first displacement sensor and the second baseline data of the second displacement sensor are acquired. Then, the first temperature drift rate of the first displacement sensor and the second temperature drift rate of the second displacement sensor are obtained by fitting the first baseline data and the second baseline data. The electromechanical brake caliper is driven to unload the clamping force, and the first voltage signal of the first displacement sensor, the second voltage signal of the second displacement sensor, and the motor coding position of the electromechanical brake caliper are continuously recorded. First displacement data is determined based on the first voltage signal and the first temperature drift rate, and second displacement data is determined based on the second voltage signal and the second temperature drift rate. Then, the true piston return curve of the electromechanical brake caliper is calculated based on the first displacement data and the second displacement data. The return stabilization time and average return speed are determined based on the piston's true return curve. The mechanical transmission chain back clearance is determined based on the first displacement data and the motor coding position. The control performance indicators of the electromechanical brake caliper are evaluated based on the piston's true return curve. The electromechanical brake caliper, the first displacement sensor, and the second displacement sensor are all mounted on the test bench. The probe of the first displacement sensor passes through the through hole opened in the brake pad and brake disc of the electromechanical brake caliper and directly contacts the center position of the piston. The probe of the second displacement sensor is fixed on the outer shell of the electromechanical brake caliper on the side away from the first displacement sensor. The connecting line between the probes of the first displacement sensor and the second displacement sensor coincides with the central axis of the piston of the electromechanical brake caliper.

[0007] Furthermore, in one embodiment of the present invention, the first temperature drift rate and the second temperature drift rate are obtained by fitting the following formula:

[0008] in, This represents the first baseline data / second baseline data at time t. This represents the ratio of the first temperature drift rate to the second temperature drift rate obtained from the fitting. This represents the constant obtained from the fitting.

[0009] Further, in one embodiment of the present invention, the step of determining the first displacement data based on the first voltage signal and the first temperature drift rate, and determining the second displacement data based on the second voltage signal and the second temperature drift rate, specifically includes: Determine the first sensitivity coefficient of the first displacement sensor and the second sensitivity coefficient of the second displacement sensor; The first voltage signal is converted into a first displacement based on the first sensitivity coefficient, and the second voltage signal is converted into a second displacement based on the second sensitivity coefficient. The first displacement data is obtained by performing temperature compensation on the first displacement amount based on the first temperature drift rate, and the second displacement data is obtained by performing temperature compensation on the second displacement amount based on the second temperature drift rate.

[0010] Furthermore, in one embodiment of the present invention, the step of calculating the true piston return curve of the electromechanical brake caliper based on the first displacement data and the second displacement data specifically includes: The first displacement change of the first displacement sensor at each time moment is determined based on the first displacement data, and the second displacement change of the second displacement sensor at each time moment is determined based on the second displacement data. The actual piston return amount at each moment is determined by the sum of the absolute values ​​of the first displacement change and the second displacement change. The piston return curve is generated based on the actual piston return amount.

[0011] Furthermore, in one embodiment of the present invention, determining the return stabilization time and average return speed based on the piston's actual return curve specifically includes: The final piston return value is determined based on the actual piston return curve. The piston return stability range is determined based on the final piston return value, and the return stability time is determined based on the moment when the piston enters the piston return stability range. The average return speed is determined based on the average slope of the piston's actual return curve before reaching the piston's final return value.

[0012] Furthermore, in one embodiment of the present invention, determining the mechanical transmission chain backlash based on the first displacement data and the motor coding position specifically includes: Compare the motor encoding position with the first displacement data on the same time axis; When the motor coding position changes and the first displacement data has a plateau period in the corresponding time period, the backlash of the mechanical transmission chain is determined based on the displacement amount during the plateau period.

[0013] Furthermore, in one embodiment of the present invention, the step of evaluating the control performance indicators of the electromechanical brake caliper based on the true piston return curve specifically includes: Calculate the theoretical piston return curve based on the motor coding position; The following error of the electromechanical brake caliper is determined based on the root mean square error between the theoretical return curve and the actual return curve of the piston.

[0014] On the other hand, embodiments of the present invention provide a floating electromechanical brake caliper piston return amount testing system, comprising: The preheating module is used to drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates a preset clamping force and continues for a preset time before unloading to 0, thereby enabling the motor, transmission mechanism and brake disc of the electromechanical brake caliper to reach the preset working temperature and working state. A drift calibration module is used to drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates the preset clamping force, and acquires the first baseline data of the first displacement sensor and the second baseline data of the second displacement sensor, and then fits the first temperature drift rate of the first displacement sensor and the second temperature drift rate of the second displacement sensor according to the first baseline data and the second baseline data. The data acquisition module is used to drive the electromechanical brake caliper to unload the clamping force and continuously record the first voltage signal of the first displacement sensor, the second voltage signal of the second displacement sensor, and the motor coding position of the electromechanical brake caliper. The return curve calculation module is used to determine the first displacement data based on the first voltage signal and the first temperature drift rate, determine the second displacement data based on the second voltage signal and the second temperature drift rate, and then calculate the true piston return curve of the electromechanical brake caliper based on the first displacement data and the second displacement data. The data processing module is used to determine the return stabilization time and average return speed based on the piston's true return curve, determine the mechanical transmission chain back clearance based on the first displacement data and the motor coding position, and evaluate the control performance indicators of the electromechanical brake caliper based on the piston's true return curve. The electromechanical brake caliper, the first displacement sensor, and the second displacement sensor are all mounted on the test bench. The probe of the first displacement sensor passes through the through hole opened in the brake pad and brake disc of the electromechanical brake caliper and directly contacts the center position of the piston. The probe of the second displacement sensor is fixed on the outer shell of the electromechanical brake caliper on the side away from the first displacement sensor. The connecting line between the probes of the first displacement sensor and the second displacement sensor coincides with the central axis of the piston of the electromechanical brake caliper.

[0015] On the other hand, embodiments of the present invention provide an electronic device, which includes a memory, a processor, a program stored in the memory and executable on the processor, and a data bus for enabling communication between the processor and the memory. When the program is executed by the processor, it implements the floating electromechanical brake caliper piston return measurement method as described above.

[0016] On the other hand, embodiments of the present invention also provide a storage medium, which is a computer-readable storage medium for computer-readable storage. The storage medium stores one or more programs, which can be executed by one or more processors to implement the floating electromechanical brake caliper piston return amount test method as described above.

[0017] On the other hand, embodiments of the present invention also provide a computer program product, including a computer program that, when executed by a processor, implements the floating electromechanical brake caliper piston return amount test method as described above.

[0018] The advantages and beneficial effects of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention: This invention integrates temperature compensation and data validity verification, reducing environmental interference, ensuring the consistency and accuracy of test data, and improving the reliability of measurement results. By analyzing dynamic characteristics such as the stability of the return process, it can detect performance degradation trends before potential faults appear, enabling early warning and enhancing the predictability of quality monitoring. When the return amount is unqualified, it can help determine whether the problem originates from control software parameters, mechanical transmission backlash, or the motor itself, providing a clear direction for rapid rectification and improving problem diagnosis capabilities. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments of the present invention are described below. It should be understood that the drawings described below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating the steps of a method for testing the piston return amount of a floating electromechanical brake caliper provided in an embodiment of the present invention; Figure 2 A schematic diagram of a test scenario for the floating electromechanical brake caliper piston return amount test method provided in an embodiment of the present invention; Figure 3A schematic diagram of the structure of the floating electromechanical brake caliper piston return measurement system provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0021] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. It should be noted that although functional modules are divided in the system schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the system schematic diagram or the order in the flowchart. The step numbers in the following embodiments are only set for ease of explanation and do not limit the order between steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0022] In the description of this invention, "multiple" means two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, the number of indicated technical features, or the order of the indicated technical features. Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0023] It should be noted that in all specific embodiments of this application, when processing data related to user identity or characteristics, such as user information, user behavior data, user historical data, and user location information, user permission or consent is obtained first. Furthermore, the collection, use, and processing of this data comply with relevant laws, regulations, and standards of the relevant countries and regions. In addition, when embodiments of this application require access to sensitive personal information of users, separate permission or consent from the user is obtained through pop-ups or redirects to confirmation pages. Only after obtaining the user's separate permission or consent is the necessary user-related data for the proper functioning of the embodiments of this application obtained.

[0024] like Figure 1 The diagram shows a flowchart of a method for testing the piston return amount of a floating electromechanical brake caliper according to an embodiment of the present invention. (Refer to...) Figure 1This invention provides a method for testing the piston return amount of a floating electromechanical brake caliper, specifically including the following steps: S101, drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates a preset clamping force and continues for a preset time before unloading to 0, thereby so that the motor, transmission mechanism and brake disc of the electromechanical brake caliper reach the preset working temperature and working state. S102. Drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates a preset clamping force, and acquire the first baseline data of the first displacement sensor and the second baseline data of the second displacement sensor, and then fit the first temperature drift rate of the first displacement sensor and the second temperature drift rate of the second displacement sensor according to the first baseline data and the second baseline data. S103, drive the electromechanical brake caliper to unload the clamping force, and continuously record the first voltage signal of the first displacement sensor, the second voltage signal of the second displacement sensor, and the motor coding position of the electromechanical brake caliper. S104. Determine the first displacement data based on the first voltage signal and the first temperature drift rate, determine the second displacement data based on the second voltage signal and the second temperature drift rate, and then calculate the true piston return curve of the electromechanical brake caliper based on the first displacement data and the second displacement data. S105. Determine the return stabilization time and average return speed based on the piston's true return curve, determine the mechanical transmission chain back clearance based on the first displacement data and the motor coding position, and evaluate the control performance indicators of the electromechanical brake caliper based on the piston's true return curve. The electromechanical brake caliper, the first displacement sensor, and the second displacement sensor are all mounted on the test bench. The probe of the first displacement sensor passes through the through hole opened in the brake pad and brake disc of the electromechanical brake caliper and directly contacts the center position of the piston. The probe of the second displacement sensor is fixed on the outer shell of the electromechanical brake caliper on the side away from the first displacement sensor. The connecting line between the probes of the first displacement sensor and the probe of the second displacement sensor coincides with the central axis of the piston of the electromechanical brake caliper.

[0025] like Figure 2The diagram shows a test scenario for the floating electromechanical brake caliper piston return measurement method provided in this embodiment of the invention. In this diagram, 2 represents the floating electromechanical brake caliper, 1 and 3 represent the first and second displacement sensors, respectively, 4 is the wiring harness, and 5 is the power supply unit used to power the electromechanical brake caliper. Measuring the piston return measurement of the floating hydraulic brake caliper requires placing the displacement sensors near the central axis of the piston with the greatest deformation. Since the caliper body slides left and right along the slide rail during the clamping process, one displacement sensor needs to be placed directly on the piston through the perforated brake pad and brake disc. The other displacement sensor is located on the caliper body shell corresponding to the piston. The piston return measurement is the sum of the absolute values ​​of the changes from the two displacement sensors.

[0026] The complete process of this invention embodiment is as follows: 1) Installation and Connection: Install the electromechanical brake caliper (EMB) on the test bench and connect the power harness and CAN communication harness according to the product technical documents; fix two high-precision displacement sensors (sensor A and sensor B) on a rigid reference frame independent of the brake caliper mounting base; the probe of sensor A passes through the specially machined extension holes on the brake pad and brake disc and directly abuts against the piston center axis area; the probe of sensor B is fixed on the brake caliper body shell, facing the piston projection area; ensure that the movement direction of the probes of both sensors is coaxial or parallel to the piston axis; 2) System preheating and pre-cycle: Drive the EMB to work via CAN bus command, so that the EMB generates clamping force to 70% of the rated clamping force (Fe), holds for 5 seconds and then unloads to zero; repeat this cycle 4 times to make the motor, transmission mechanism and brake disc reach a stable working temperature and working state. 3) Baseline establishment and temperature drift calibration: Drive the EMB again to maintain the clamping force at 70% Fe; after the system stabilizes (pressure and displacement reading fluctuations are less than 0.1% of full scale), perform the following operations: (1) Zero the two displacement sensors using software and set this state as the displacement reference; (2) Simultaneously acquire baseline data from two displacement sensors for at least 5 seconds, with a sampling rate of not less than 1kHz; (3) Perform linear fitting on the baseline data and calculate the real-time temperature drift rate of sensor A and sensor B respectively. and ; 4) Synchronous data acquisition during release process: Send a release command to EMB via CAN bus; at the same time as the command is sent, the data acquisition system is triggered to continuously record the following data for at least 60 seconds at a sampling rate of not less than 1kHz: (1) Voltage signal of sensor A (2) Voltage signal of sensor B (3) Motor encoder position fed back by EMB via CAN bus Motor torque Motor temperature ; 5) Data processing and feature extraction, the specific sub-steps are as follows: (1) Signal conversion and temperature compensation: converting the sensor voltage signal , Based on its sensitivity coefficient , Convert to displacement , Then, the measured drift rate is used for real-time temperature compensation to obtain accurate displacement data. ; .

[0027] (2) Calculate the actual piston return: Calculate the displacement changes of the two sensors from the release moment (t=0) to t=60 seconds: , The physical meaning of the algorithm for calculating the piston return amount S = |ΔA| + |ΔB| is that by taking the absolute values ​​and adding them together, the interference components with opposite signs and similar magnitudes introduced by the rigid sliding of the clamp body in ΔA and ΔB can be effectively canceled, thereby extracting the true return amount of the piston relative to the clamp body. (3) Extract dynamic characteristic parameters: Analyze the displacement curve of the entire return process. and : Stabilization time Find the time required from the start of release until the return amount S(t) enters and remains within ±2% of the final value S(60); average return speed Calculate the average slope of the S(t) curve in the interval from t=0.1s to 1.0s; (4) System performance diagnosis (data fusion analysis): Backlash identification: This involves analyzing the position change curve of the motor encoder. curve with external displacement sensor A Compare; if Changes If there is a plateau period in the initial stage, the displacement during this plateau period is the backlash of the mechanical transmission chain. Control performance evaluation: The actual return trajectory S(t) is compared with the theoretical return trajectory calculated based on the motor encoder theory to evaluate its control performance indicators such as following error and overshoot. 6) Generate a comprehensive diagnostic report: The output report should include at least the following: Key results: Piston return distance S, and a pass / fail judgment is given by comparing it with the technical specifications; Dynamic performance: Settling time , average return speed ; System diagnostics: Identified backlash size, control performance rating (e.g., excellent, good, need attention); Data quality: Data Quality Index (DQI), calculated based on signal-to-noise ratio and curve continuity.

[0028] It can be recognized that the embodiments of the present invention reduce environmental interference by integrating temperature compensation and data validity verification, ensuring the consistency and accuracy of test data and improving the reliability of measurement results; by analyzing dynamic characteristics such as the stability of the return process, performance degradation trends can be detected before potential faults appear, enabling early warning and enhancing the predictability of quality monitoring; when the return amount is unqualified, it can help determine whether the problem originates from control software parameters, mechanical transmission backlash, or the motor itself, providing a clear direction for rapid rectification and improving problem diagnosis capabilities.

[0029] As a further optional implementation, the first temperature drift rate and the second temperature drift rate are obtained by fitting the following formula:

[0030] in, This represents the first baseline data / second baseline data at time t. This represents the ratio of the first temperature drift rate to the second temperature drift rate obtained from the fitting. This represents the constant obtained from the fitting.

[0031] As a further optional implementation, a first displacement data is determined based on a first voltage signal and a first temperature drift rate, and a second displacement data is determined based on a second voltage signal and a second temperature drift rate, specifically including: S201. Determine the first sensitivity coefficient of the first displacement sensor and the second sensitivity coefficient of the second displacement sensor; S202. Convert the first voltage signal into a first displacement amount according to the first sensitivity coefficient, and convert the second voltage signal into a second displacement amount according to the second sensitivity coefficient; S203. Perform temperature compensation on the first displacement amount according to the first temperature drift rate to obtain the first displacement data, and perform temperature compensation on the second displacement amount according to the second temperature drift rate to obtain the second displacement data.

[0032] Specifically, the raw data is imported and aligned to ensure that all data channels (displacement sensors, CAN bus) are strictly synchronized in time.

[0033] 1. Timestamp Alignment: During data acquisition, a hardware trigger signal is used to assign a uniform timestamp to all channels. During processing, with the trigger time t=0, all data streams are interpolated and aligned to ensure synchronization accuracy better than 1 millisecond.

[0034] 2. Anomaly Removal: Check if the message cycle of the CAN bus data is continuous. If message loss is found (e.g., discontinuous ID sequence), remove all data at the corresponding time point and record it as an invalid interval.

[0035] Signal conversion and physical dimension restoration convert the acquired raw voltage values ​​into physically meaningful engineering values ​​(such as micrometers and Newtons).

[0036] 1. Sensor Calibration: The calibration is performed using the unique sensitivity coefficient G (unit: μm / V or mm / V) for each sensor. .

[0037] 2. Unit unification: All displacement quantities are unified to micrometers (μm), and forces are unified to Newtons (N) to avoid errors in order of magnitude calculation.

[0038] Real-time temperature drift compensation eliminates reading drift caused by temperature changes in sensors and measurement systems.

[0039] 1. Baseline data selection: During the pressurization and holding phase, once the system has stabilized, the data from the last 5 seconds is selected as the baseline.

[0040] 2. Drift rate (δ) calculation: based on baseline data Perform linear regression fitting: The fitting slope δ is the drift rate (unit: μm / s).

[0041] 3. Full Data Compensation: For all data collected during the release phase, compensation is performed according to the formula... Perform point-by-point compensation.

[0042] As a further optional implementation, the true piston return curve of the electromechanical brake caliper is calculated based on the first displacement data and the second displacement data, specifically including: S301. Determine the first displacement change of the first displacement sensor at each time based on the first displacement data, and determine the second displacement change of the second displacement sensor at each time based on the second displacement data. S302. Determine the actual piston return amount at each moment based on the sum of the absolute values ​​of the first displacement change and the second displacement change. S303. Generate the true piston return curve based on the true piston return amount.

[0043] Specifically, eliminate the interference of the clamp body sliding and calculate the actual return amount of the piston.

[0044] 1. Baseline value confirmation: Confirm that the value of the compensated displacement data at the release time t=0 has been zeroed by the previous zeroing.

[0045] 2. Calculation of Change: Calculate the change in displacement from t=0 to t=60s:

[0046]

[0047] 3. Algorithm execution: Calculate the final return amount S = |ΔA| + |ΔB|. This algorithm uses the addition of absolute values ​​to cancel out the contributions of the clamp body sliding in ΔA and ΔB with opposite signs, thereby extracting the true return amount of the piston.

[0048] Meanwhile, based on the above algorithm, the actual piston return amount at each moment is calculated to obtain the actual piston return curve.

[0049] As a further optional implementation, the return stabilization time and average return speed are determined based on the piston's actual return curve, specifically including: S401. Determine the final piston return value based on the piston's actual return curve. S402. Determine the piston return stability range based on the piston's final return value, and determine the return stability time based on the moment the piston enters the piston return stability range. S403. Determine the average return speed based on the average slope of the piston's actual return curve before reaching the final return value.

[0050] Specifically, dynamic feature parameters are extracted to comprehensively evaluate the dynamic performance of the repositioning process.

[0051] 1. Calculate the settling time ( ): Calculate the average value of the displacement data in the last second. ; Set the stability threshold as ±2%; Starting from t=0, search backwards to find the first time point. This ensures that all subsequent data points of S(t) fall within the threshold range. .

[0052] 2. Average return speed ( ): Calculate the average slope of the S(t) curve during the initial recovery period (e.g., from t=0.1s to t=1.0s).

[0053] 3. Curve smoothness ( ): Calculate the standard deviation of the second derivative (acceleration) of the data points during the middle of the homing process (e.g., from t=10s to t=30s). The smaller the standard deviation, the smoother the homing process and the less abnormal the jitter.

[0054] As a further optional implementation, the mechanical transmission chain backlash is determined based on the first displacement data and the motor coding position, specifically including: S501. Compare the motor coding position with the first displacement data on the same time axis; S502. When the motor coding position changes and the first displacement data has a plateau period in the corresponding time period, the mechanical transmission chain backlash is determined based on the displacement amount during the plateau period.

[0055] Specifically, the motor encoder displacement change curve read from the CAN bus is compared with the displacement curve of external sensor A. Plot them on the same timeline; observe the initial return phase, when the encoder shows the motor has started to reverse (displacement change), and... The curve remains on a plateau (with very small changes) for a period of time, and the displacement of this plateau is the mechanical transmission backlash.

[0056] As a further optional implementation, the control performance indicators of the electromechanical brake caliper are evaluated based on the piston's true return curve, specifically including: S601. Calculate the theoretical piston return curve based on the motor coding position; S602. Determine the following error of the electromechanical brake caliper based on the root mean square error between the theoretical return curve and the actual return curve of the piston.

[0057] Specifically, the theoretical piston return curve calculated based on encoder theory is compared with the actual return curve S(t) measured by external sensors, and the root mean square error (RMSE) between the two is calculated as the following error index of the control system.

[0058] In some optional embodiments, an error analysis process is also included, as detailed below: 1. Error source identification and classification: Systematically identify and classify all error sources that may affect the measurement results.

[0059] 1) Systematic errors (correctable / estimateable): (1) Sensor error: Read from the calibration certificate, including: Accuracy class: e.g., ±0.5% of F.S. (full scale); Nonlinear error: e.g., <±0.1%FS; Zero-point temperature drift: e.g., ±0.05%FS / °C.

[0060] (2) Installation error: The misalignment angle θ between the sensor probe axis and the piston axis is measured by a laser collimator, and the error introduced is: .

[0061] (3) Temperature compensation residual: The standard deviation of the residual of the compensation model (linear fitting) is the remaining error that was not fully compensated.

[0062] (4) Algorithm approximation error: The core algorithm S=|ΔA|+|ΔB| is an approximation based on an ideal model, and its theoretical deviation can be estimated through simulation.

[0063] 2) Random error (statistical characteristics): Environmental vibration: assessed by analyzing the power spectral density of high-frequency data (e.g., >100Hz).

[0064] Electrical noise: Calculate the standard deviation of displacement readings during the "static" phase of pressurization.

[0065] Mechanism fluctuations: Minor crawling or shaking of the EMB drive chain manifests as high-frequency, minute fluctuations on the return curve.

[0066] 2. Quantitative assessment of systematic errors: All types of systematic errors are uniformly quantified as their impact on the final result S.

[0067] 1) Sensitivity coefficient calculation: Analyze each error source The degree of influence on the final result S, i.e., the sensitivity coefficient. .

[0068] For example, the error of sensor A The sensitivity coefficient to S is 1.

[0069] 2) Synthesis of systematic error limits: The synthesis limit of systematic effects is calculated using the root sum of squares (RSS) method.

[0070] 3. Statistical analysis of random errors (Type A uncertainty assessment): Based on the measurement data itself, assess the uncertainty introduced by random effects.

[0071] 1) Data selection: During the stable period after the return process ends (e.g., from t=50s to t=60s), select 100 data points of S(t).

[0072] 2) Statistical analysis: Calculate the arithmetic mean of this set of data. And the Bessel standard deviation σ.

[0073] The formula for calculating Type A standard uncertainty is: , where n is the sample size (here n=100).

[0074] 3) Normality test (optional): Use the Shapiro-Wilke test to verify whether the data in the stable segment follows a normal distribution. If it does, then the above evaluation method is valid.

[0075] 4. Combination and Reporting of Measurement Uncertainty: Provide the reliability range of the final measurement results.

[0076] 1) Combined standard uncertainty ( ): ,in Uncertainty introduced for system effects Type A uncertainty is introduced for random effects.

[0077] 2) Expanded uncertainty (U): The inclusion factor k is typically set to 2 (corresponding to approximately a 95% confidence level). The final results are reported as follows: , Unit: mm.

[0078] 5. Automatic determination of measurement result reliability: Provides automated decision-making basis for quality control.

[0079] 1) Uncertainty threshold check: Based on the measurement task requirements, set a maximum permissible uncertainty. (1 / 3 of the return amount tolerance). If The accuracy of this measurement meets the requirements.

[0080] 2) Data validity check: Signal-to-noise ratio (SNR) calculation: If NR > 20dB, the signal quality is considered good.

[0081] Curve continuity check: Calculate the first difference of the displacement curve and check for jump points exceeding 3 times the standard deviation to determine whether the data is inaccurate due to interference.

[0082] 3) Final decision output: pass: R > 20 dB, and there are no abnormal jumps. The results are reliable.

[0083] Warning: One metric did not reach the threshold. The results are for reference only; it is recommended to analyze the reasons.

[0084] Failure: Multiple metrics failed to meet thresholds. The results are unreliable; retesting is recommended.

[0085] The method steps of the embodiments of the present invention have been described above. It is understood that the embodiments of the present invention, by integrating temperature compensation and data validity verification, reduce environmental interference, ensure the consistency and accuracy of test data, and improve the reliability of measurement results; by analyzing the dynamic characteristics such as the stability of the return process, performance degradation trends can be detected before potential faults appear, enabling early warning and enhancing the predictability of quality monitoring; when the return amount is unqualified, it can help determine whether the problem originates from control software parameters, mechanical transmission backlash, or the motor itself, providing a clear direction for rapid rectification and improving problem diagnosis capabilities.

[0086] like Figure 3 The diagram shown is a structural schematic of the floating electromechanical brake caliper piston return measurement system provided in an embodiment of the present invention. (Refer to...) Figure 3 This invention provides a floating electromechanical brake caliper piston return measurement system, comprising: The preheating module is used to drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates a preset clamping force and continues for a preset time before unloading to 0, thereby enabling the motor, transmission mechanism and brake disc of the electromechanical brake caliper to reach the preset working temperature and working state. The drift calibration module is used to drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates a preset clamping force, and acquires the first baseline data of the first displacement sensor and the second baseline data of the second displacement sensor, and then fits the first temperature drift rate of the first displacement sensor and the second temperature drift rate of the second displacement sensor based on the first baseline data and the second baseline data. The data acquisition module is used to drive the electromechanical brake caliper to unload the clamping force and continuously record the first voltage signal of the first displacement sensor, the second voltage signal of the second displacement sensor, and the motor coding position of the electromechanical brake caliper. The return curve calculation module is used to determine the first displacement data based on the first voltage signal and the first temperature drift rate, determine the second displacement data based on the second voltage signal and the second temperature drift rate, and then calculate the true piston return curve of the electromechanical brake caliper based on the first displacement data and the second displacement data. The data processing module is used to determine the return stabilization time and average return speed based on the piston's actual return curve, determine the mechanical transmission chain back clearance based on the first displacement data and the motor coding position, and evaluate the control performance indicators of the electromechanical brake caliper based on the piston's actual return curve. The electromechanical brake caliper, the first displacement sensor, and the second displacement sensor are all mounted on the test bench. The probe of the first displacement sensor passes through the through hole opened in the brake pad and brake disc of the electromechanical brake caliper and directly contacts the center position of the piston. The probe of the second displacement sensor is fixed on the outer shell of the electromechanical brake caliper on the side away from the first displacement sensor. The connecting line between the probes of the first displacement sensor and the probe of the second displacement sensor coincides with the central axis of the piston of the electromechanical brake caliper.

[0087] It is understood that the content of the above method embodiments is applicable to this system embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0088] This invention also provides an electronic device, comprising: a memory, a processor, a program stored in the memory and executable on the processor, and a data bus for communication between the processor and the memory. When the program is executed by the processor, it implements the aforementioned method for testing the piston return amount of a floating electromechanical brake caliper. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0089] like Figure 4 The diagram shown is a hardware structure schematic of an electronic device provided in an embodiment of the present invention. (Refer to...) Figure 4 This invention provides an electronic device, comprising: The processor 401 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present invention. The memory 402 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 402 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 402 and called by the processor 401 to execute the floating electromechanical brake caliper piston return amount test method of the embodiments of the present invention. Input / output interface 403 is used to implement information input and output; The communication interface 404 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 405 transmits information between various components of the device (e.g., processor 401, memory 402, input / output interface 403, and communication interface 404); The processor 401, memory 402, input / output interface 403 and communication interface 404 are connected to each other within the device via bus 405.

[0090] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0091] This invention also provides a storage medium, which is a computer-readable storage medium for computer-readable storage. The storage medium stores one or more programs, which can be executed by one or more processors to implement the above-described floating electromechanical brake caliper piston return amount test method.

[0092] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0093] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0094] This invention also provides a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform... Figure 1 The method shown.

[0095] It is understood that the content of the above method embodiments is applicable to the embodiments of this program product. The specific functions implemented by the embodiments of this program product are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0096] The embodiments described in this invention are for the purpose of more clearly illustrating the technical solutions of the embodiments of this invention, and do not constitute a limitation on the technical solutions provided by the embodiments of this invention. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this invention are also applicable to similar technical problems.

[0097] The terms "first," "second," "third," "fourth," etc. (if present) in the specification and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0098] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the aforementioned blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0099] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the aforementioned functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0100] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0101] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0102] More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the aforementioned program can be printed, because the aforementioned program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0103] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0104] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0105] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0106] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for testing the piston return amount of a floating electromechanical brake caliper, characterized in that, Includes the following steps: The electromechanical brake caliper is driven to work, so that the electromechanical brake caliper generates a preset clamping force and continues for a preset time before being unloaded to 0, thereby enabling the motor, transmission mechanism and brake disc of the electromechanical brake caliper to reach the preset working temperature and working state. The electromechanical brake caliper is driven to work, so that the electromechanical brake caliper generates the preset clamping force, and the first baseline data of the first displacement sensor and the second baseline data of the second displacement sensor are acquired. Then, the first temperature drift rate of the first displacement sensor and the second temperature drift rate of the second displacement sensor are obtained by fitting the first baseline data and the second baseline data. The electromechanical brake caliper is driven to unload the clamping force, and the first voltage signal of the first displacement sensor, the second voltage signal of the second displacement sensor, and the motor coding position of the electromechanical brake caliper are continuously recorded. First displacement data is determined based on the first voltage signal and the first temperature drift rate, and second displacement data is determined based on the second voltage signal and the second temperature drift rate. Then, the true piston return curve of the electromechanical brake caliper is calculated based on the first displacement data and the second displacement data. The return stabilization time and average return speed are determined based on the piston's true return curve. The mechanical transmission chain back clearance is determined based on the first displacement data and the motor coding position. The control performance indicators of the electromechanical brake caliper are evaluated based on the piston's true return curve. The electromechanical brake caliper, the first displacement sensor, and the second displacement sensor are all mounted on the test bench. The probe of the first displacement sensor passes through the through hole opened in the brake pad and brake disc of the electromechanical brake caliper and directly contacts the center position of the piston. The probe of the second displacement sensor is fixed on the outer shell of the electromechanical brake caliper on the side away from the first displacement sensor. The connecting line between the probes of the first displacement sensor and the second displacement sensor coincides with the central axis of the piston of the electromechanical brake caliper.

2. The method for testing the piston return amount of a floating electromechanical brake caliper according to claim 1, characterized in that, The first temperature drift rate and the second temperature drift rate are obtained by fitting the following formula: in, This represents the first baseline data / second baseline data at time t. This represents the ratio of the first temperature drift rate to the second temperature drift rate obtained from the fitting. This represents the constant obtained from the fitting.

3. The method for testing the piston return amount of a floating electromechanical brake caliper according to claim 1, characterized in that, The step of determining the first displacement data based on the first voltage signal and the first temperature drift rate, and determining the second displacement data based on the second voltage signal and the second temperature drift rate, specifically includes: Determine the first sensitivity coefficient of the first displacement sensor and the second sensitivity coefficient of the second displacement sensor; The first voltage signal is converted into a first displacement based on the first sensitivity coefficient, and the second voltage signal is converted into a second displacement based on the second sensitivity coefficient. The first displacement data is obtained by performing temperature compensation on the first displacement amount based on the first temperature drift rate, and the second displacement data is obtained by performing temperature compensation on the second displacement amount based on the second temperature drift rate.

4. The method for testing the piston return amount of a floating electromechanical brake caliper according to claim 1, characterized in that, The calculation of the true piston return curve of the electromechanical brake caliper based on the first displacement data and the second displacement data specifically includes: The first displacement change of the first displacement sensor at each time moment is determined based on the first displacement data, and the second displacement change of the second displacement sensor at each time moment is determined based on the second displacement data. The actual piston return amount at each moment is determined by the sum of the absolute values ​​of the first displacement change and the second displacement change. The piston return curve is generated based on the actual piston return amount.

5. The method for testing the piston return amount of a floating electromechanical brake caliper according to claim 1, characterized in that, The step of determining the return stabilization time and average return speed based on the piston's actual return curve specifically includes: The final piston return value is determined based on the actual piston return curve. The piston return stability range is determined based on the final piston return value, and the return stability time is determined based on the moment when the piston enters the piston return stability range. The average return speed is determined based on the average slope of the piston's actual return curve before reaching the piston's final return value.

6. The method for testing the piston return amount of a floating electromechanical brake caliper according to claim 1, characterized in that, The step of determining the mechanical transmission chain backlash based on the first displacement data and the motor coding position specifically includes: Compare the motor encoding position with the first displacement data on the same time axis; When the motor coding position changes and the first displacement data has a plateau period in the corresponding time period, the backlash of the mechanical transmission chain is determined based on the displacement amount during the plateau period.

7. The method for testing the piston return amount of a floating electromechanical brake caliper according to claim 1, characterized in that, The evaluation of the control performance indicators of the electromechanical brake caliper based on the piston's true return curve specifically includes: Calculate the theoretical piston return curve based on the motor coding position; The following error of the electromechanical brake caliper is determined based on the root mean square error between the theoretical return curve and the actual return curve of the piston.

8. A floating electromechanical brake caliper piston return measurement system, characterized in that, include: The preheating module is used to drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates a preset clamping force and continues for a preset time before unloading to 0, thereby enabling the motor, transmission mechanism and brake disc of the electromechanical brake caliper to reach the preset working temperature and working state. A drift calibration module is used to drive the electromechanical brake caliper to work, so that the electromechanical brake caliper generates the preset clamping force, and acquires the first baseline data of the first displacement sensor and the second baseline data of the second displacement sensor, and then fits the first temperature drift rate of the first displacement sensor and the second temperature drift rate of the second displacement sensor according to the first baseline data and the second baseline data. The data acquisition module is used to drive the electromechanical brake caliper to unload the clamping force and continuously record the first voltage signal of the first displacement sensor, the second voltage signal of the second displacement sensor, and the motor coding position of the electromechanical brake caliper. The return curve calculation module is used to determine the first displacement data based on the first voltage signal and the first temperature drift rate, determine the second displacement data based on the second voltage signal and the second temperature drift rate, and then calculate the true piston return curve of the electromechanical brake caliper based on the first displacement data and the second displacement data. The data processing module is used to determine the return stabilization time and average return speed based on the piston's true return curve, determine the mechanical transmission chain back clearance based on the first displacement data and the motor coding position, and evaluate the control performance indicators of the electromechanical brake caliper based on the piston's true return curve. The electromechanical brake caliper, the first displacement sensor, and the second displacement sensor are all mounted on the test bench. The probe of the first displacement sensor passes through the through hole opened in the brake pad and brake disc of the electromechanical brake caliper and directly contacts the center position of the piston. The probe of the second displacement sensor is fixed on the outer shell of the electromechanical brake caliper on the side away from the first displacement sensor. The connecting line between the probes of the first displacement sensor and the second displacement sensor coincides with the central axis of the piston of the electromechanical brake caliper.

9. An electronic device, characterized in that, The electronic device includes a memory, a processor, a program stored in the memory and executable on the processor, and a data bus for enabling communication between the processor and the memory. When the program is executed by the processor, it implements the floating electromechanical brake caliper piston return measurement method as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the floating electromechanical brake caliper piston return measurement method as described in any one of claims 1 to 7.

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