Motor vehicle and trailer anti-lock braking performance non-destructive testing system

Abstract

This invention relates to a non-destructive testing system for the anti-lock braking performance of motor vehicles and trailers, belonging to the field of vehicle braking performance testing technology. The system includes: a data acquisition and control module that acquires vehicle motion state data output from vehicle speed and wheel speed sensors, integrating them to form a multi-source sensor dataset; a data synchronization processing module that preprocesses the sensor data and calculates the instantaneous linear velocity and instantaneous slip ratio of each wheel, generating continuous slip ratio time-series data throughout the braking process; a wheel speed coefficient calibration module that automatically calibrates the wheel speed coefficient under stable vehicle coasting conditions and dynamically corrects wheel speed coefficient drift through an adaptive calibration mechanism; and a braking performance evaluation output module that generates characteristic curves based on the slip ratio time-series data, extracts key quantitative parameters, judges braking performance according to preset standards, and outputs a standardized test report. This system achieves direct quantitative non-destructive testing of vehicle anti-lock braking performance.

Description

Technical Field

[0001] This invention belongs to the field of vehicle braking performance testing technology, specifically relating to a non-destructive testing system for the anti-lock braking performance of motor vehicles and trailers. Background Technology

[0002] Anti-lock braking systems (ABS) are core devices for ensuring vehicle safety. Accurate braking performance testing plays a crucial role in vehicle factory verification, periodic safety inspections, and traffic safety management. In existing related technologies, prior art document CN102230942 A discloses a vehicle braking performance testing scheme. However, it primarily estimates braking performance by collecting indirect parameters such as brake line pressure and vehicle deceleration, without using wheel slip ratio as the core testing indicator. This results in low alignment with the actual working mechanism of ABS, leading to poor testing accuracy and reliability. Furthermore, this scheme uses a dedicated sensor assembly structure, requiring disassembly of vehicle components for installation, lacking versatility and convenience. It also lacks automatic wheel speed coefficient calibration, dynamic calibration, and continuous slip ratio detection throughout the entire process. Currently, mainstream testing methods in the industry still largely rely on indoor fixed bench testing or manual road vehicle sampling. Traditional testing equipment has a limited functional architecture, only capable of simple collection of basic sensor data and rough qualitative judgments, lacking continuous, quantitative, and non-destructive testing capabilities throughout the entire process. The testing coverage and precision are significantly limited.

[0003] In existing detection schemes, various motion state sensing units are deployed independently, and each sensing unit independently carries out data acquisition according to its own built-in timing. The system does not establish a unified global timing benchmark, nor does it set up a multi-unit synchronous control mechanism. The data collected by different sensing units have timing misalignment and time offset problems, which makes it impossible to accurately match the vehicle speed and wheel rotation data at the same moment. This directly increases the basic error of subsequent slip rate calculation and makes it difficult to meet the data matching requirements of high-precision detection.

[0004] Traditional detection equipment has a rudimentary processing logic for multi-source sensor data, using only simple filtering methods and lacking a standardized and complete multi-source data preprocessing mechanism. During vehicle operation, satellite positioning signals are prone to attenuation and brief signal loss. Existing equipment cannot switch to an appropriate data fusion and computing mode in a timely manner, making it difficult to continuously calculate the vehicle's true motion state under abnormal signal conditions and unable to output continuous and stable vehicle speed data and slip rate time-series data.

[0005] The wheel speed parameters corresponding to the vehicle wheel speed conversion are easily affected by external factors such as tire wear, tire pressure fluctuations, and changes in vehicle load, resulting in continuous deviations. Conventional testing equipment lacks whole-machine self-calibration logic and is not equipped with an adaptive correction mechanism for wheel speed coefficients. During long-term continuous operation of the equipment, parameter drift errors accumulate continuously, and the wheel speed calculation deviation cannot be corrected in real time, causing the braking performance test results to gradually become distorted over time.

[0006] Conventional testing modes can only output scattered, single-item test values, and cannot fully plot the time-series change curve of slip ratio throughout the braking process, nor can they systematically extract various key quantitative parameters during the braking phase. The test results lack unified and standardized judgment criteria and output formats, making it impossible to form structured and standardized test reports, which is difficult to adapt to the actual application requirements of high-precision, automated, quantitative, and non-destructive testing of anti-lock braking performance of modern vehicles. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, this invention provides a non-destructive testing system for the anti-lock braking performance of motor vehicles and trailers. The objective of this invention can be achieved through the following technical solution: include: The data acquisition and control module acquires vehicle motion state data output by vehicle speed sensor and wheel speed sensor, receives rotation pulse signals of each wheel directly controlled by anti-lock braking system and real-time vehicle operation data, and outputs multi-source sensor dataset after integrating all data. The data synchronization processing module, based on a multi-source sensor dataset, executes a data preprocessing algorithm to filter out abnormal data points; counts the number of rotation pulses of each wheel per unit time, calculates the instantaneous linear velocity and instantaneous slip ratio of each wheel in real time, and generates continuous slip ratio time-series data for the entire braking process. The wheel speed coefficient calibration module identifies stable coasting conditions of the vehicle, uses the travel distance output by the vehicle speed sensor as a benchmark, and counts the total number of rotation pulses of each wheel within the corresponding time period; it automatically calculates and stores the travel distance coefficient corresponding to the single pulse of each wheel; during continuous detection, it compares the deviation between the real-time vehicle speed and the wheel speed converted vehicle speed, and dynamically corrects wheel speed coefficient drift through the wheel speed coefficient adaptive calibration mechanism. The braking performance evaluation output module generates characteristic curves and extracts key quantitative parameters of the braking process based on slip ratio time-series data; it determines the compliance of braking performance according to preset standards, and finally outputs a standardized test report, while saving the original test data and screenshots of the operation interface.

[0008] Specifically, the process of acquiring the vehicle motion state data output by the vehicle speed sensor and wheel speed sensor is as follows: The vehicle speed sensor uses satellite positioning technology to receive navigation satellite signals and calculate the vehicle's speed and cumulative distance traveled in real time. The wheel speed sensor is a general-purpose quick-install wheel speed sensor. According to the preset minimum multiple of the number of process holes in the wheel hub, a corresponding number of equal-length steel wire ropes with locks are passed through the process holes in the wheel hub to form a ring. Then, the same number of short steel wire ropes with double locks are taken, and the two ends are respectively fastened to the evenly distributed holes of the rope ring pull plate and the ring locks to obtain the rotation pulse signals of each wheel controlled by the anti-lock braking system.

[0009] Specifically, the process of using the data preprocessing algorithm to filter out outlier data points is as follows: Remove invalid data points that exceed the preset physical range of the sensor, and eliminate abrupt abnormal values ​​caused by electromagnetic interference or sensor jitter. Random noise in sensor signals is filtered out by a moving average filtering algorithm, while signals that reflect the true motion state of the vehicle are retained, and the storage format and data accuracy of different types of data are unified.

[0010] Specifically, the process of calculating the instantaneous linear velocity and instantaneous slip ratio of each wheel in real time is as follows: Based on the pre-stored wheel speed coefficients for each wheel, the number of wheel rotation pulses collected per unit time is converted into the instantaneous linear velocity of the corresponding wheel. The instantaneous slip ratio of the corresponding wheel is calculated based on the relative relationship between the vehicle's real-time speed and the wheel's instantaneous linear velocity. The instantaneous slip ratio directly characterizes the degree of slippage between the wheel and the ground.

[0011] Specifically, the process of generating continuous slip ratio time-series data throughout the braking process is as follows: All calculated slip ratio values ​​from the moment braking begins to the moment the vehicle comes to a complete stop are arranged in chronological order of collection time. For abnormal periods with missing data, linear interpolation is used to fill in the gaps based on the effective slip ratio values ​​of adjacent moments, ultimately forming continuous and complete slip ratio time-series data for the entire braking process of the anti-lock braking system.

[0012] Specifically, the process of counting the total number of rotation pulses of each wheel within the corresponding time period is as follows: Lock the start and end times of the vehicle entering the preset stable coasting condition to obtain the calibration time period; During the calibration period, the pulse signals output by each wheel speed sensor are continuously acquired at a fixed sampling frequency, and all valid pulses are accumulated and counted. Under the preset stable coasting conditions, the vehicle travels at a constant speed, and the total number of pulses obtained reflects the proportional relationship between wheel rotation and vehicle travel distance.

[0013] Specifically, the process of automatically calculating and storing the travel distance coefficient corresponding to the single pulse of each wheel is as follows: Calculate the ratio of the actual distance traveled by the vehicle output by the vehicle speed sensor to the total number of pulses on the corresponding wheels within the calibration period to obtain the actual distance traveled by the vehicle corresponding to a single pulse signal; The actual distance traveled by the vehicle is set as the wheel speed coefficient of the corresponding wheel, and the wheel speed coefficients of all wheels are written to the non-volatile storage area, automatically replacing the original historical parameters in the storage area.

[0014] Specifically, the process of implementing the wheel speed coefficient adaptive calibration mechanism is as follows: The system continuously retrieves real-time vehicle speed data and wheel speed data calculated based on wheel speed coefficients, and calculates the relative deviation ratio between the two sets of speed data in real time. Compare the deviation ratio with the preset critical value; if it exceeds the preset critical value, the wheel speed coefficient micro-correction process is initiated. Adjust the wheel speed coefficient correction amount based on the positive or negative direction and fluctuation range of the data deviation, and constrain the adjustment range of a single parameter.

[0015] Specifically, the process of generating the characteristic curve and extracting key quantitative parameters of the braking process is as follows: Using the starting point of the locking braking action as the origin of the coordinate system, the time dimension as the horizontal coordinate scale, and the slip ratio value calculated at each time step as the vertical coordinate scale, a continuous change characteristic curve of the slip ratio throughout the entire process is plotted. The peak, mean, duration, rate of increase, and rate of decrease of the slip ratio are picked up along the curve's trajectory. The rationality of the picked parameters is verified item by item, and abnormal data components that deviate from the preset normal range are filtered out.

[0016] Specifically, the process of finally outputting the standardized test report is as follows: The system integrates the slip ratio parameters, vehicle speed parameters, and performance judgment results generated throughout the braking process. Based on a preset fixed template, it sequentially fills in the detection period, basic vehicle information, various performance index values, and working condition judgment conclusions. It gathers various types of information to generate standardized testing reports, and unifies the information arrangement logic and data presentation format within the reports.

[0017] The beneficial effects of this invention are as follows: By performing regularization and preprocessing on the collected vehicle motion state data, filtering and noise reduction and anomaly removal are used to optimize the quality of the raw data. The instantaneous slip rate of each wheel is calculated and interpolation is performed to complete missing and abnormal data periods, forming complete and continuous slip rate time-series data for the entire braking process, effectively improving the calculation deviation caused by sensor data disorder. At the same time, by setting vehicle stable slip state recognition and calibration logic and wheel speed coefficient adaptive correction mechanism, the wheel speed coefficient calibration calculation is automatically completed based on actual driving conditions. The difference between the actual vehicle speed and the wheel speed converted to vehicle speed is compared in real time and the wheel speed coefficient drift is dynamically compensated, weakening the error accumulation caused by long-term equipment operation and tire wear. It can also accurately extract key quantitative indicators of braking based on the slip rate time-series change trajectory, complete the anti-lock braking performance identification according to unified judgment rules, and generate a standardized test report. With the help of universal quick-install wheel speed sensors, non-destructive adaptation installation of vehicle models can be achieved, greatly improving the accuracy, stability, universality and regularity of vehicle anti-lock braking performance testing. Attached Figure Description

[0018] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 This is the system architecture of the non-destructive testing system for the anti-lock braking performance of motor vehicles and trailers according to the present invention; Figure 2 This is a data flow diagram of the non-destructive testing system for the anti-lock braking performance of motor vehicles and trailers according to the present invention; Figure 3 This is a schematic diagram of the main operation interface of the motor vehicle anti-lock braking performance testing system of the present invention. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0021] Please see Figure 1-3 Non-destructive testing system for anti-lock braking performance of motor vehicles and trailers; include: The data acquisition and control module acquires vehicle motion state data output by vehicle speed sensor and wheel speed sensor, receives rotation pulse signals of each wheel directly controlled by anti-lock braking system and real-time vehicle operation data, and outputs multi-source sensor dataset after integrating all data. The data synchronization processing module, based on a multi-source sensor dataset, executes a data preprocessing algorithm to filter out abnormal data points; counts the number of rotation pulses of each wheel per unit time, calculates the instantaneous linear velocity and instantaneous slip ratio of each wheel in real time, and generates continuous slip ratio time-series data for the entire braking process. The wheel speed coefficient calibration module identifies stable coasting conditions of the vehicle, uses the travel distance output by the vehicle speed sensor as a benchmark, and counts the total number of rotation pulses of each wheel within the corresponding time period; it automatically calculates and stores the travel distance coefficient corresponding to the single pulse of each wheel; during continuous detection, it compares the deviation between the real-time vehicle speed and the wheel speed converted vehicle speed, and dynamically corrects wheel speed coefficient drift through the wheel speed coefficient adaptive calibration mechanism. The braking performance evaluation output module generates characteristic curves and extracts key quantitative parameters of the braking process based on slip ratio time-series data; it determines the compliance of braking performance according to preset standards, and finally outputs a standardized test report, while saving the original test data and screenshots of the operation interface.

[0022] In this embodiment, vehicle motion state data refers to the raw physical quantity signals collected and output by various sensing modules, specifically including wheel rotation pulse signals output by wheel speed sensors, latitude and longitude coordinates and absolute vehicle speed signals output by satellite positioning modules; Multi-source sensor datasets refer to the structured data collection formed after integrating and processing the above-mentioned original sensor data, which provides the basic input for subsequent data operations; Vehicle speed and wheel speed data refer to two types of core motion parameters obtained through calculation. Specifically, they include the actual vehicle speed output by the satellite positioning module, and the instantaneous linear velocity of each wheel calculated based on the wheel speed pulse signal and wheel speed coefficient. These are the basic data for calculating wheel slip ratio and performing wheel speed coefficient calibration. Key quantitative parameters of the braking process refer to the core numerical indicators extracted from the slip ratio time-series characteristic curve and used to determine braking performance. Specifically, they include the peak slip ratio, the average slip ratio, the duration of the peak slip ratio, the slip ratio increase rate, and the slip ratio decrease rate. These parameters together constitute the quantitative basis for determining the compliance of braking performance. The actual driving distance data of the vehicle is collected during the process of determining the wheel speed coefficient in the original data index of vehicle driving distance. Specifically, it includes the cumulative driving distance data output by the satellite positioning module during the stable coasting period, which is the benchmark data for calculating the driving distance and wheel speed coefficient corresponding to a single pulse. Specifically, the process of acquiring the vehicle motion state data output by the vehicle speed sensor and wheel speed sensor is as follows: The vehicle speed sensor uses satellite positioning technology to receive navigation satellite signals and calculate the vehicle's speed and cumulative distance traveled in real time. The wheel speed sensor is a general-purpose quick-install wheel speed sensor. According to the preset minimum multiple of the number of process holes in the wheel hub, a corresponding number of equal-length steel wire ropes with locks are passed through the process holes in the wheel hub to form a ring. Then, the same number of short steel wire ropes with double locks are taken, and the two ends are respectively fastened to the evenly distributed holes of the rope ring pull plate and the ring locks to obtain the rotation pulse signals of each wheel controlled by the anti-lock braking system.

[0023] Specifically, the process of using the data preprocessing algorithm to filter out outlier data points is as follows: Remove invalid data points that exceed the preset physical range of the sensor, and eliminate abrupt abnormal values ​​caused by electromagnetic interference or sensor jitter. Random noise in sensor signals is filtered out by a moving average filtering algorithm, while signals that reflect the true motion state of the vehicle are retained, and the storage format and data accuracy of different types of data are unified.

[0024] Specifically, the process of calculating the instantaneous linear velocity and instantaneous slip ratio of each wheel in real time is as follows: Based on the pre-stored wheel speed coefficients for each wheel, the number of wheel rotation pulses collected per unit time is converted into the instantaneous linear velocity of the corresponding wheel. The instantaneous slip ratio of the corresponding wheel is calculated based on the relative relationship between the vehicle's real-time speed and the wheel's instantaneous linear velocity. The instantaneous slip ratio directly characterizes the degree of slippage between the wheel and the ground.

[0025] Specifically, the process of generating continuous slip ratio time-series data throughout the braking process is as follows: All calculated slip ratio values ​​from the moment braking begins to the moment the vehicle comes to a complete stop are arranged in chronological order of collection time. For abnormal periods with missing data, linear interpolation is used to fill in the gaps based on the effective slip ratio values ​​of adjacent moments, ultimately forming continuous and complete slip ratio time-series data for the entire braking process of the anti-lock braking system.

[0026] Specifically, the process of counting the total number of rotation pulses of each wheel within the corresponding time period is as follows: Lock the start and end times of the vehicle entering the preset stable coasting condition to obtain the calibration time period; During the calibration period, the pulse signals output by each wheel speed sensor are continuously acquired at a fixed sampling frequency, and all valid pulses are accumulated and counted. Under the preset stable coasting conditions, the vehicle travels at a constant speed, and the total number of pulses obtained reflects the proportional relationship between wheel rotation and vehicle travel distance.

[0027] Specifically, the process of automatically calculating and storing the travel distance coefficient corresponding to the single pulse of each wheel is as follows: Calculate the ratio of the actual distance traveled by the vehicle output by the vehicle speed sensor to the total number of pulses on the corresponding wheels within the calibration period to obtain the actual distance traveled by the vehicle corresponding to a single pulse signal; The actual distance traveled by the vehicle is set as the wheel speed coefficient of the corresponding wheel, and the wheel speed coefficients of all wheels are written to the non-volatile storage area, automatically replacing the original historical parameters in the storage area.

[0028] Specifically, the process of implementing the wheel speed coefficient adaptive calibration mechanism is as follows: The system continuously retrieves real-time vehicle speed data and wheel speed data calculated based on wheel speed coefficients, and calculates the relative deviation ratio between the two sets of speed data in real time. Compare the deviation ratio with the preset critical value; if it exceeds the preset critical value, the wheel speed coefficient micro-correction process is initiated. Adjust the wheel speed coefficient correction amount based on the positive or negative direction and fluctuation range of the data deviation, and constrain the adjustment range of a single parameter.

[0029] Specifically, the process of generating the characteristic curve and extracting key quantitative parameters of the braking process is as follows: Using the starting point of the locking braking action as the origin of the coordinate system, the time dimension as the horizontal coordinate scale, and the slip ratio value calculated at each time step as the vertical coordinate scale, a continuous change characteristic curve of the slip ratio throughout the entire process is plotted. The peak, mean, duration, rate of increase, and rate of decrease of the slip ratio are picked up along the curve's trajectory. The rationality of the picked parameters is verified item by item, and abnormal data components that deviate from the preset normal range are filtered out.

[0030] Specifically, the process of finally outputting the standardized test report is as follows: The system integrates the slip ratio parameters, vehicle speed parameters, and performance judgment results generated throughout the braking process. Based on a preset fixed template, it sequentially fills in the detection period, basic vehicle information, various performance index values, and working condition judgment conclusions. It gathers various types of information to generate standardized testing reports, and unifies the information arrangement logic and data presentation format within the reports.

[0031] In this embodiment, the specific process of executing the data preprocessing algorithm to filter out abnormal data points is as follows: The system integrates the vehicle motion state data collected by the vehicle speed sensor and wheel speed sensor to construct a multi-source sensor dataset with a unified format; a moving average filtering algorithm with a window length of 5 points is used to smooth and reduce noise in the original collected signals, effectively filtering out electromagnetic interference, line coupling interference, and high-frequency noise signals generated by slight sensor jitter; at the same time, a fixed threshold is set to remove invalid data points and abrupt jump abnormal values ​​that exceed the rated physical range of the sensor, unifying the sampling frequency, storage format, and data accuracy of the two sensor data, eliminating the calculation error caused by the difference in data format from the source, and providing a clean and reliable basic data source for subsequent linear velocity conversion and slip ratio calculation.

[0032] In this embodiment, the data acquisition and control module integrates multi-source sensor data in the following way: the floating-point vehicle speed data output by the vehicle speed sensor and the pulse count data output by the wheel speed sensor are uniformly converted into the double-precision floating-point format defined by the system, and stored in association with the acquisition time as the index to form a structured multi-source sensor dataset, thereby eliminating the format differences between different sensor data.

[0033] In this embodiment, the specific process of calculating the instantaneous linear velocity and instantaneous slip ratio of each wheel in real time is as follows: The system is set to continuously collect wheel rotation pulse signals at a fixed sampling period of 20ms. Based on the wheel speed coefficients stored in the device, the number of pulses accumulated within a unit sampling period is converted into the instantaneous linear velocity of the corresponding wheel. Combined with the real-time vehicle speed output by satellite positioning, the instantaneous slip ratio of each wheel is calculated and matched according to the motion correlation between the two. This slip ratio parameter can intuitively characterize the degree of adhesion and slippage between the wheel and the ground during braking, and is the core quantitative basis for evaluating the dynamic adjustment performance of the anti-lock braking system.

[0034] In this embodiment, the method for determining the braking start time and the vehicle complete stop time is as follows: the system takes the moment when it detects that the wheel slip ratio starts to rise continuously from 0% as the braking start time, and takes the moment when the vehicle's real-time speed drops to 0 km / h and there is no speed fluctuation for three consecutive sampling periods as the vehicle complete stop time, accurately locking the start and end intervals of the entire braking process, and providing clear boundaries for the generation of slip ratio time series data.

[0035] In this embodiment, the specific process of generating continuous slip ratio time-series data for the entire braking process is as follows: taking the moment when the vehicle brake pedal is triggered as the starting node and the moment when the vehicle comes to a complete stop as the ending node, all slip ratio values ​​calculated at 20ms intervals throughout the entire braking cycle are arranged in strict order according to the time axis; for short-term abnormal periods of missing data caused by external interference, a linear interpolation algorithm is used to complete and fit based on two adjacent sets of effective slip ratio values ​​to eliminate time-series breakpoints and form continuous, uninterrupted, and continuously analyzable slip ratio time-series data.

[0036] In this embodiment, the specific process of counting the total number of rotation pulses of each wheel within the corresponding time period is as follows: the system monitors the vehicle's driving conditions in real time, and when the detected vehicle speed change rate is less than 0.5 m / s... 2 When the driving state tends to be stable, it is determined that it has entered the stable coasting calibration condition, and the start and end times of the calibration period are automatically locked. During the locked period, the pulse signals of each wheel are continuously collected at a fixed high-frequency sampling rate, and the effective pulses are counted one by one. Under the stable coasting condition, the wheel rotation and the vehicle travel distance are linearly related, and the total number of pulses obtained can be used as the standard reference quantity for wheel speed coefficient calculation.

[0037] In this embodiment, the specific process of automatically calculating and storing the travel distance coefficient corresponding to the single pulse of each wheel is as follows: extract the accurate cumulative travel distance data output by the vehicle speed sensor within the calibration period, combine it with the total number of pulses accumulated by each wheel within the same period, and solve the actual travel distance of the vehicle corresponding to the single pulse signal through linear ratio calculation; assign this value as the independent wheel speed coefficient of the corresponding wheel to distinguish the parameter differences under different tire wear conditions; uniformly write it into the non-volatile storage area of ​​the device's industrial-grade electronic hard disk, automatically overwrite the original historical parameters, and realize the automatic updating and retention of coefficients.

[0038] In this embodiment, the non-volatile storage area is a dedicated partition of the system's built-in industrial-grade electronic hard disk, which can permanently save the wheel speed coefficient and historical detection data after the device is powered off. When the newly calibrated wheel speed coefficient is written, it will automatically overwrite the original historical parameters, while retaining the backup record of the previous version coefficient to avoid parameter loss.

[0039] In this embodiment, the specific process of implementing the wheel speed coefficient adaptive calibration mechanism is as follows: During the normal testing of the equipment, the actual vehicle speed measured by satellite positioning and the equivalent wheel speed derived from the wheel speed coefficient are retrieved simultaneously, and the relative deviation ratio of the two sets of vehicle speed data is calculated in real time; a 1.0% threshold is preset as the critical threshold for deviation. When the measured deviation exceeds this threshold, the wheel speed coefficient micro-correction process is automatically started; the correction amount is adaptively matched according to the positive and negative trend and fluctuation amplitude of the deviation, while constraining the single coefficient adjustment amplitude to not exceed 0.5%, avoiding parameter mutations, dynamically compensating for wheel speed coefficient drift caused by tire wear and environmental temperature drift, and maintaining the system detection accuracy in the long term.

[0040] In this embodiment, the preset deviation threshold value for adaptive calibration of wheel speed coefficient is 1.0%, and the maximum single coefficient correction is 0.5%. This threshold is set based on the industry accuracy requirements for motor vehicle braking performance testing, which ensures timely compensation for wheel speed coefficient drift and avoids parameter mutations affecting testing stability. The preset standard for braking performance judgment is the relevant standard of national motor vehicle safe operation technical conditions. The system compares the extracted quantitative parameters with the standard threshold and automatically generates a pass / fail judgment result.

[0041] In this embodiment, the specific process of generating characteristic curves and extracting key quantitative parameters of the braking process is as follows: the starting node of the braking action is locked as the origin of the coordinate system, a 20ms time step is used as the horizontal time axis, and the range of slip ratio change from 0 to 100% is used as the vertical numerical axis to accurately draw the continuous change characteristic curve of slip ratio throughout the entire process; five core indicators, namely, peak slip ratio, average slip ratio, peak duration, slip ratio increase rate, and slip ratio decrease rate, are automatically picked up along the curve trajectory; the physical rationality of each parameter is verified simultaneously, abnormal values ​​that deviate from the vehicle braking law are eliminated, and a standardized performance evaluation parameter set is formed.

[0042] In this embodiment, the specific process of finally outputting a standardized test report is as follows: The system summarizes the time-series data of the braking slip ratio, real-time vehicle speed data, wheel speed data, and performance judgment results. Referring to the national standard inspection specifications, a fixed report format is preset, and the test time, basic vehicle information, values ​​of various performance indicators, and qualification judgment conclusions are filled in sequentially. The internal data arrangement logic, number of digits retained, and text presentation format of the report are unified to generate a standardized test report. It supports local storage, on-site printing, and simultaneous archiving of data screenshots, meeting the requirements for traceable and archiveable test results.

[0043] In this embodiment, the universal quick-install wheel speed sensor adopts an improved wire rope installation method. According to the preset minimum multiple of the number of wheel hub process hole intervals, a corresponding number of wire ropes of the same specification with locks are passed through the wheel hub process holes to form a closed ring. Then, the same number of short wire ropes with double locks are configured, and the two ends are respectively fastened to the rope ring pull plate, the evenly distributed hole position and the ring lock. The entire process does not require disassembly of the axle bolts and axle cover structure. A single person can complete the non-destructive assembly in a short time. It is compatible with wheel hub installation of different models and stably collects continuous rotation pulse signals of each wheel.

[0044] In this embodiment, the system hardware consists of a data acquisition and processing host, a touchscreen industrial panel PC, an industrial-grade electronic hard disk, a satellite positioning vehicle speed sensor, a universal quick-install wheel speed sensor, and a series-type external control switch. The interface board, main board, and power board of the data acquisition and processing host all adopt a double-sided printed circuit board layout without through holes to reduce crosstalk and electromagnetic coupling interference. The touchscreen industrial panel PC has 22 built-in standardized operating interfaces, covering the entire process of vehicle information entry, system coefficient calibration, braking performance testing, historical data query, and report export. The operating logic is standardized and easy to use by on-site inspection personnel.

[0045] In this embodiment, after the vehicle braking test is completed and the performance judgment is finalized, the system automatically triggers the saving mechanism to simultaneously archive the original test data and the screenshot of the operation interface. The original data fully retains core parameters such as braking duration, braking distance, real-time wheel speed of each wheel, and changes in the slip ratio throughout the process. The screenshot accurately records the real-time display content of the test interface. This dual retention method ensures that the test data is authentic, valid, and tamper-proof, which meets the requirements for traceability management of motor vehicle safety test data.

[0046] In this embodiment, the application scenario is a motor vehicle safety inspection agency conducting periodic testing of the anti-lock braking performance of a three-axle heavy-duty truck. The specific process is as follows: N is the size of the moving average filter window, T3 is the data sampling interval, A is the stable coasting speed change rate threshold, B is the stable coasting acceleration fluctuation threshold, S is the calibrated standard driving distance, P is the wheel speed coefficient correction trigger threshold, and Q is the maximum amplitude of a single coefficient correction. Data acquisition and control module: Universal quick-mount wheel speed sensors are installed at the wheel hubs of each wheel of the vehicle under inspection, and satellite positioning vehicle speed sensors are installed on the top of the vehicle; after the system starts, it completes the initial configuration of the sensing equipment, acquires the real-time vehicle operation data output by the vehicle speed sensor and the rotation pulse signals of each wheel output by the wheel speed sensor, centrally integrates all the acquired information, and outputs a standardized multi-source sensor dataset after standardizing the data format, providing raw data support for subsequent data processing and parameter calculation.

[0047] Data synchronization processing module: Receives multi-source sensor datasets output by the data acquisition and control module and performs data preprocessing. It uses a moving average filtering algorithm with a window size of N to filter out high-frequency noise interference in the sensor signals, eliminates abnormal data points exceeding the physical range, and unifies the sampling format and data accuracy of different sensor data. Using T3 as a fixed data sampling interval, it converts the number of wheel rotation pulses into instantaneous linear velocity based on pre-stored wheel speed coefficients. Combining the relative relationship between the vehicle's real-time speed and the instantaneous linear velocity of the wheels, it calculates the instantaneous slip ratio of each wheel. For abnormal time periods with missing data, it uses linear interpolation to complete the data, generating continuous and complete slip ratio time-series data for the entire braking process.

[0048] Wheel speed coefficient calibration module: After system startup and initialization, it continuously monitors the vehicle's driving status and brake pedal operation status. Once the brake pedal is confirmed to be in an untriggered state, it monitors the real-time rate of change of vehicle speed and the fluctuation amplitude of longitudinal acceleration. When the rate of change of vehicle speed is less than A, it determines that the vehicle has entered a stable coasting state and automatically triggers the wheel speed coefficient calibration process. During calibration, it collects vehicle driving data and wheel rotation pulse data corresponding to a standard driving distance of S meters. It calculates the distance traveled per pulse based on the correspondence between driving distance and the total number of pulses, sets this as the wheel speed coefficient for each wheel, and stores it. During continuous detection, it continuously compares the real-time vehicle speed with the wheel speed converted to vehicle speed. When the relative deviation rate exceeds P, it initiates a minor correction process for the wheel speed coefficient, adjusting the coefficient correction amount according to the direction and magnitude of the deviation, constraining the single correction amplitude to not exceed Q, effectively correcting the drift problem caused by long-term use of the wheel speed coefficient.

[0049] Braking performance evaluation output module: Receives slip ratio time-series data output from the data synchronization processing module. Using the brake pedal trigger moment as the origin and time as the horizontal axis and slip ratio value as the vertical axis, it plots a continuous slip ratio characteristic curve. Along the curve's trajectory, it extracts the slip ratio peak value, average value, peak duration, rate of increase, and rate of decrease. Simultaneously, it extracts key quantitative parameters such as braking time, braking distance, average deceleration, wheel lock-up time, and braking coordination time. Each extracted parameter is compared item by item with preset national standards to automatically determine braking performance compliance. It integrates all test data and judgment results, generating a standardized test report according to the national standard's format framework. The report supports local storage, instant printing with a thermal printer, and data export to a USB drive. It also retains the original test data and interface screenshots to ensure traceability and verification of test results.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A non-destructive testing system for the anti-lock braking performance of motor vehicles and trailers, characterized in that, include: The data acquisition and control module acquires vehicle motion state data output by vehicle speed sensor and wheel speed sensor, receives rotation pulse signals of each wheel directly controlled by anti-lock braking system and real-time vehicle operation data, and outputs multi-source sensor dataset after integrating all data. The data synchronization processing module, based on a multi-source sensor dataset, executes a data preprocessing algorithm to filter out abnormal data points; The number of rotation pulses of each wheel per unit time is counted, and the instantaneous linear velocity and instantaneous slip ratio of each wheel are calculated in real time to generate continuous slip ratio time series data for the entire braking process. The wheel speed coefficient calibration module identifies stable coasting conditions of the vehicle, uses the travel distance output by the vehicle speed sensor as a benchmark, and counts the total number of rotation pulses of each wheel within the corresponding time period; it automatically calculates and stores the travel distance coefficient corresponding to the single pulse of each wheel. During continuous testing, the deviation between the real-time vehicle speed and the wheel speed converted into vehicle speed is compared, and the wheel speed coefficient drift is dynamically corrected through the wheel speed coefficient adaptive calibration mechanism. The braking performance evaluation output module generates characteristic curves and extracts key quantitative parameters of the braking process based on slip ratio time-series data. The braking performance is judged to be qualified according to the preset standards, and a standardized test report is finally output. At the same time, the original test data and the screenshot of the operation interface are saved.

2. The system according to claim 1, characterized in that, The specific process for acquiring the vehicle motion state data output by the vehicle speed sensor and wheel speed sensor is as follows: The vehicle speed sensor uses satellite positioning technology to receive navigation satellite signals and calculate the vehicle's speed and cumulative distance traveled in real time. The wheel speed sensor is a general-purpose quick-install wheel speed sensor. According to the preset minimum multiple of the number of process holes in the wheel hub, a corresponding number of equal-length steel wire ropes with locks are passed through the process holes in the wheel hub to form a ring. Then, the same number of short steel wire ropes with double locks are taken, and the two ends are respectively fastened to the evenly distributed holes of the rope ring pull plate and the ring locks to obtain the rotation pulse signals of each wheel controlled by the anti-lock braking system.

3. The system according to claim 1, characterized in that, The specific process of using the data preprocessing algorithm to filter out outlier data points is as follows: Remove invalid data points that exceed the preset physical range of the sensor, and eliminate abrupt abnormal values ​​caused by electromagnetic interference or sensor jitter. Random noise in sensor signals is filtered out by a moving average filtering algorithm, while signals that reflect the true motion state of the vehicle are retained, and the storage format and data accuracy of different types of data are unified.

4. The system according to claim 1, characterized in that, The specific process for calculating the instantaneous linear velocity and instantaneous slip ratio of each wheel in real time is as follows: Based on the pre-stored wheel speed coefficients for each wheel, the number of wheel rotation pulses collected per unit time is converted into the instantaneous linear velocity of the corresponding wheel. The instantaneous slip ratio of the corresponding wheel is calculated based on the relative relationship between the vehicle's real-time speed and the wheel's instantaneous linear velocity. The instantaneous slip ratio directly characterizes the degree of slippage between the wheel and the ground.

5. The system according to claim 1, characterized in that, The specific process for generating continuous slip ratio time-series data throughout the braking process is as follows: All calculated slip ratio values ​​from the moment braking begins to the moment the vehicle comes to a complete stop are arranged in chronological order of collection time. For abnormal periods with missing data, linear interpolation is used to fill in the gaps based on the effective slip ratio values ​​of adjacent moments, ultimately forming continuous and complete slip ratio time-series data for the entire braking process of the anti-lock braking system.

6. The system according to claim 1, characterized in that, The specific process for calculating the total number of rotation pulses of each wheel within the corresponding time period is as follows: Lock the start and end times of the vehicle entering the preset stable coasting condition to obtain the calibration time period; During the calibration period, the pulse signals output by each wheel speed sensor are continuously acquired at a fixed sampling frequency, and all valid pulses are accumulated and counted. Under the preset stable coasting conditions, the vehicle travels at a constant speed, and the total number of pulses obtained reflects the proportional relationship between wheel rotation and vehicle travel distance.

7. The system according to claim 1, characterized in that, The specific process of automatically calculating and storing the travel distance coefficient corresponding to the single pulse of each wheel is as follows: Calculate the ratio of the actual distance traveled by the vehicle output by the vehicle speed sensor to the total number of pulses on the corresponding wheels within the calibration period to obtain the actual distance traveled by the vehicle corresponding to a single pulse signal; The actual distance traveled by the vehicle is set as the wheel speed coefficient of the corresponding wheel, and the wheel speed coefficients of all wheels are written to the non-volatile storage area, automatically replacing the original historical parameters in the storage area.

8. The system according to claim 1, characterized in that, The specific process of implementing the adaptive calibration mechanism for wheel speed coefficient is as follows: The system continuously retrieves real-time vehicle speed data and wheel speed data calculated based on wheel speed coefficients, and calculates the relative deviation ratio between the two sets of speed data in real time. Compare the deviation ratio with the preset critical value; if it exceeds the preset critical value, the wheel speed coefficient micro-correction process is initiated. Adjust the wheel speed coefficient correction amount based on the positive or negative direction and fluctuation range of the data deviation, and constrain the adjustment range of a single parameter.

9. The system according to claim 1, characterized in that, The specific process of generating characteristic curves and extracting key quantitative parameters of the braking process is as follows: Using the starting point of the locking braking action as the origin of the coordinate system, the time dimension as the horizontal coordinate scale, and the slip ratio value calculated at each time step as the vertical coordinate scale, a continuous change characteristic curve of the slip ratio throughout the entire process is plotted. The peak, mean, duration, rate of increase, and rate of decrease of the slip ratio are picked up along the curve's trajectory. The rationality of the picked parameters is verified item by item, and abnormal data components that deviate from the preset normal range are filtered out.

10. The system according to claim 1, characterized in that, The specific process for finally outputting the standardized test report is as follows: The system integrates the slip ratio parameters, vehicle speed parameters, and performance judgment results generated throughout the braking process. Based on a preset fixed template, it sequentially fills in the detection period, basic vehicle information, various performance index values, and working condition judgment conclusions. It gathers various types of information to generate standardized testing reports, and unifies the information arrangement logic and data presentation format within the reports.

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