A wheel speed sensor hardware-in-the-loop simulation system and method

Abstract

The application relates to the technical field of automobile electronic hardware-in-the-loop test, in particular to a wheel speed sensor hardware-in-the-loop simulation system and method, which comprises a wheel speed simulator, an actual vehicle wheel speed sensor, an actual vehicle gear ring and an upper computer, the wheel speed simulator comprises a motor, a motor controller, a gear ring fixing mechanism, a wheel speed sensor adjusting mechanism and an ABS / ESC controller; the application calculates target wheel speeds of each wheel through a vehicle dynamics model of the upper computer, drives the motor to coaxially rotate the actual vehicle gear ring, collects wheel speed signals through the actual vehicle wheel speed sensor and sends the wheel speed signals into the ABS / ESC controller, and then feeds back to the upper computer through a CAN network to form a closed-loop simulation, the core algorithm comprises four parts of signal generation, signal processing, mode switching and test verification; the application can discover and solve potential problems in the early development stage, improves test repeatability, effectively shortens the development cycle, reduces the research and development cost, and avoids the risk of hardware modification and product recall in the later stage.

Description

Technical Field

[0001] This invention relates to the field of automotive electronic hardware-in-the-loop testing technology, specifically a wheel speed sensor hardware-in-the-loop simulation system and method. Background Technology

[0002] With the rapid development of the automotive industry, consumers have increasingly higher requirements for vehicle safety performance. Active safety technologies such as anti-lock braking system (ABS), electronic stability control system (ESC), and traction control system (TCS) have become standard equipment in modern cars. The core function of such active safety systems relies on the accurate measurement and real-time control of wheel speed. The accuracy and reliability of wheel speed sensors directly determine the overall performance of the vehicle's active safety system.

[0003] In the traditional development and testing process of wheel speed sensors, performance testing usually relies on actual vehicle or bench tests. This testing method has significant technical drawbacks. Building a complex real vehicle or bench test environment requires a large investment of manpower and hardware, and the entire testing process is time-consuming, making it difficult to meet the rapid iteration needs of wheel speed sensors and vehicle active safety systems. Therefore, in view of the above situation, there is an urgent need to develop a hardware-in-the-loop simulation system and method for wheel speed sensors to overcome the shortcomings in current practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide a hardware-in-the-loop simulation system and method for wheel speed sensors to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A hardware-in-the-loop simulation system for wheel speed sensors includes a host computer and a wheel speed simulator. The host computer has a built-in vehicle dynamics simulation module. The wheel speed simulator includes a motor and a motor controller. The motor controller is communicatively connected to the host computer and is used to drive the motor. It also includes a real vehicle gear ring and a real vehicle wheel speed sensor. The wheel speed simulator also includes a gear ring fixing mechanism, a wheel speed sensor adjustment mechanism, and an ABS / ESC controller. The gear ring fixing mechanism is connected to the output shaft of the motor for coaxially fixing the actual gear ring, so as to drive the actual gear ring to rotate synchronously with the motor; The wheel speed sensor adjustment mechanism is used to fix the actual wheel speed sensor and adjust the relative position between the actual wheel speed sensor and the actual vehicle gear ring. The signal output terminal of the actual vehicle wheel speed sensor is electrically connected to the ABS / ESC controller, and is used to collect the wheel speed signal generated during the rotation of the actual vehicle gear ring, and send the wheel speed signal to the ABS / ESC controller; The ABS / ESC controller is communicatively connected to the host computer and is used to receive the wheel speed signal and execute the corresponding vehicle control algorithm, while feeding back the processed wheel speed signal to the host computer. The host computer is also used to update the state parameters of the vehicle dynamics simulation module based on the feedback wheel speed signal, forming a closed-loop simulation test circuit.

[0006] As a further aspect of the present invention: the motor is a servo motor, and the wheel speed, steering and acceleration of the motor are all precisely controlled in a closed loop by a motor controller; The motor controller includes a lower-level machine and a servo driver. The input terminal of the lower-level machine is communicatively connected to the upper-level machine, and the output terminal is electrically connected to the control terminal of the servo driver. The power output terminal of the servo driver is electrically connected to the power supply terminal of the motor, and is used to drive the motor to operate according to the control commands forwarded by the lower-level machine.

[0007] As a further aspect of the present invention: the gear ring fixing mechanism is used to constrain the coaxiality of the actual vehicle gear ring and the motor output shaft, and to suppress the vibration and radial offset during the rotation of the actual vehicle gear ring; The wheel speed sensor adjustment mechanism is used to adjust the installation position, installation angle, and air gap between the actual wheel speed sensor and the actual vehicle gear ring to match the installation requirements of different vehicle models. The actual vehicle wheel speed sensor is a Hall effect wheel speed sensor that matches the parameters of the actual vehicle being tested.

[0008] As a further aspect of the present invention: the ABS / ESC controller is connected to the host computer via the vehicle's CAN network, and is used to convert the received wheel speed signal into a CAN signal and upload it to the vehicle's CAN network for the host computer to collect. The host computer's vehicle dynamics simulation module supports CarSim's built-in vehicle models or user-defined vehicle models, and is used to calculate the instantaneous target wheel speed of each wheel based on the input simulation condition parameters.

[0009] As a further aspect of the present invention, it also includes a signal generation unit and a signal processing unit; The signal generation unit is integrated into the vehicle dynamics simulation module of the host computer. It is used to establish a vehicle motion model based on the vehicle dynamics principle, calculate the expected wheel speed of each wheel based on the input parameters, and generate pulse signals or analog signals corresponding to the wheel speed. The signal processing unit is integrated into the ABS / ESC controller or host computer and is used to filter and calculate the wheel speed of the collected wheel speed signal to obtain the effective wheel speed.

[0010] As a further aspect of the present invention: the signal processing unit uses a low-pass filter to filter the wheel speed signal, and simultaneously calculates the wheel speed by sampling the rising and falling edges of the pulse signal. If the difference between the wheel speed calculated at the rising edge and the wheel speed calculated at the falling edge is within the preset allowable range, then the average of the two is taken as the effective wheel speed for this cycle. If the difference between the two exceeds the preset allowable range, the value that is closer to the effective wheel speed of the previous cycle will be taken as the effective wheel speed of the current cycle.

[0011] A wheel speed sensor hardware-in-the-loop simulation method, implemented based on the aforementioned wheel speed sensor hardware-in-the-loop simulation system, includes the following steps: S1: The host computer calculates the instantaneous target wheel speed of each wheel based on the input simulation parameters through the vehicle dynamics simulation module, and sends the corresponding control commands to the motor controller. S2: The motor controller drives the motor to run according to the received control command, and drives the actual vehicle gear ring to rotate coaxially with the motor through the gear ring fixing mechanism; S3: The actual vehicle wheel speed sensor collects the wheel speed signal corresponding to the rotation of the actual vehicle gear ring and sends the wheel speed signal to the ABS / ESC controller; S4: The ABS / ESC controller receives wheel speed signals and executes the corresponding vehicle control algorithm, while feeding back the processed wheel speed signals to the host computer. S5: The host computer updates the state parameters of the vehicle dynamics simulation module based on the feedback wheel speed signal, completing one closed-loop simulation iteration.

[0012] As a further aspect of the present invention: in step S1, the simulation working condition parameters include vehicle speed, steering angle, road surface adhesion coefficient, number of teeth on the gear ring, and wheel rolling radius; In step S2, the motor controller converts the target wheel speed into the phase sequence and phase voltage driving parameters of the motor, and drives the motor to perform rotational actions according to the speed, direction and acceleration corresponding to the target wheel speed; In step S3, the installation position, installation angle, and air gap between the actual vehicle wheel speed sensor and the actual vehicle gear ring are adjusted by the wheel speed sensor adjustment mechanism to match the installation requirements of different vehicle models. In step S4, the ABS / ESC controller converts the wheel speed signal into a CAN signal and sends it to the vehicle's CAN network for acquisition by the host computer.

[0013] As a further aspect of the present invention, the method further includes signal generation and signal processing steps: The signal generation steps are as follows: establish a vehicle motion model based on the principles of vehicle dynamics, calculate the expected wheel speed of each wheel based on the input parameters, and generate a pulse signal or analog signal corresponding to the wheel speed. The signal processing steps are as follows: a low-pass filter is used to filter the acquired wheel speed signal. At the same time, the wheel speed is calculated at the rising and falling edges of the sampling pulse signal. If the difference between the wheel speed calculated at the rising edge and the wheel speed calculated at the falling edge is within a preset allowable range, the average of the two is taken as the effective wheel speed of the current cycle. If the difference exceeds the preset allowable range, the value that is closer to the effective wheel speed of the previous cycle is taken as the effective wheel speed of the current cycle.

[0014] As a further aspect of the present invention, the method further includes mode switching and testing verification steps: The mode switching steps are to automatically switch between low-speed operation mode and high-speed operation mode according to the frequency of the input signal to adapt to the wheel speed signal characteristics at different vehicle speeds. In low-speed operation mode, if the time since the last detection of the tooth signal exceeds a preset threshold, the corresponding signal is retransmitted. In high-speed operation mode, non-essential data units after the speed pulse may not be fully transmitted, while data units being transmitted are transmitted in full. The testing and verification steps involve monitoring and verifying the entire simulation testing process.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention introduces a wheel speed simulator to build a hardware-in-the-loop simulation system for wheel speed sensors. This system can identify and resolve potential technical problems in the early stages of the development of wheel speed sensors and vehicle active safety systems, effectively avoiding the risks of expensive hardware modifications and product recalls in the later stages. Meanwhile, the repeatability of wheel speed sensor simulation tests based on the simulation system and method of the present invention is significantly improved, which facilitates regression testing and performance optimization of wheel speed sensors and vehicle active safety systems. Furthermore, the technical solution of this invention can effectively shorten the development cycle of wheel speed sensors and vehicle active safety systems, reduce R&D costs, and help enterprises enhance their core competitiveness. Attached Figure Description

[0016] Figure 1 This is a block diagram of the overall architecture of the wheel speed sensor hardware-in-the-loop simulation system in an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0019] Please see Figure 1 The present invention provides a hardware-in-the-loop simulation system and method for wheel speed sensors, which is used for hardware-in-the-loop simulation of wheel speed signals of vehicle models. It can solve the defects of existing technologies, such as high R&D costs, long development cycles, poor test repeatability, and difficulty in meeting the needs of rapid product iteration, which are caused by wheel speed sensor testing relying on actual vehicle or bench tests.

[0020] I. Hardware-in-the-Loop Simulation System for Wheel Speed ​​Sensors The wheel speed sensor hardware-in-the-loop simulation system provided in this embodiment includes a wheel speed simulator, a real wheel speed sensor, and a real vehicle gear ring; the wheel speed simulator includes a motor, a motor controller, a gear ring fixing mechanism, a wheel speed sensor adjustment mechanism, an ABS / ESC controller, and also includes a host computer that is communicatively connected to the motor controller.

[0021] The core logic of this system is integrated into digital models and signal processing algorithms. It can simulate pulse signals or analog signals generated by wheel rotation for testing and verification by vehicle control systems such as ABS and ESC. The specific details are as follows: The motor is a servo motor. To meet the requirements of a vehicle speed range of 0-200 km / h and a steady-state error of <0.5 km / h, assuming a wheel radius of 0.3 m, n_wheel = v / 2πr = (200×1000 / 3600) / (2π×0.3)≈291 rpm, considering the transmission ratio, a rated motor speed greater than or equal to 3000 rpm, a rated torque of 0.48 Nm, and a moment of inertia of 2.7×10-6 kg·m² is recommended. A 20-bit incremental encoder is used to cover high speeds with sufficient margin. The servo driver uses speed control to reduce errors in the intermediate transmission process and increase the positioning accuracy of the entire system. In the closed-loop control loop, the current loop bandwidth is 1-2 kHz to quickly suppress load disturbances, the speed loop bandwidth is 300-500 Hz to balance dynamic response and stability and avoid resonance, and the position loop is 50-100 Hz only for pulse signal generation and is not a primary control loop. The inner loop bandwidth should ideally be 5-10 times that of the outer loop to ensure hierarchical control stability. As the system's power source, its output shaft is connected to the gear ring fixing mechanism. The gear ring is rigidly connected to the central flange via bolts. The flange serves as the main connection interface with the output shaft. The output shaft flange and the gear ring flange are paired and fastened with high-strength bolts to form a rigid connection. The evenly distributed high-strength bolts provide sufficient preload to ensure flange surface contact, transmit torque, and suppress relative slippage. Precision-fitting bosses (stops) and grooves are machined on both the gear ring flange and the output shaft flange. The core components of the connection include the gear ring, gear ring fixing mechanism, motor, Hall effect wheel speed sensor, and wheel speed sensor adjustment mechanism. A coaxial fixing mechanical structure is adopted, with the core being the use of a multi-stage mechanical structure to achieve high-precision coaxiality between the gear ring and the output shaft, reliable torque transmission, and vibration suppression. The coaxiality constraint accuracy is approximately 0.02-0.05mm, and the radial runout control range is ≤0.05mm. The specific number of teeth on the gear ring depends on the vehicle model and controller calibration requirements, commonly 44-60 teeth, with an outer diameter of 150-300mm. It is used to simulate the rotation of a real vehicle wheel by rotating itself, and its wheel speed, steering and acceleration can be precisely controlled by a motor controller.

[0022] The high-precision controllability of servo motors can replicate various dynamic rotation conditions of real vehicle wheels, providing stable and accurate power input for wheel speed simulation and ensuring the basic accuracy of wheel speed simulation.

[0023] The motor controller includes a servo driver and a lower-level machine. The input terminal of the lower-level machine is communicatively connected to the upper-level machine, and the output terminal is electrically connected to the control terminal of the servo driver. The power output terminal of the servo driver is electrically connected to the power supply terminal of the servo motor. The motor controller is used to receive control commands issued by the upper-level machine, calculate the simulator control quantity based on the analog signals and analog parameters of the test bench network, and then adjust the output parameters of the motor to simulate the dynamic working conditions of the vehicle and drive the motor to complete the corresponding rotational action.

[0024] Through closed-loop control of the motor controller, the digital wheel speed signal of the host computer vehicle model can be quickly and accurately converted into the physical rotation motion of the servo motor, realizing real-time linkage between digital simulation and hardware execution, and ensuring the consistency between the simulated working conditions and the simulation model.

[0025] The gear ring is a standard gear ring with parameters completely consistent with those of the actual vehicle gear ring. The gear ring is coaxially fixed on the output shaft of the motor through a gear ring fixing mechanism, which is used to provide the wheel speed sensor with a sensing target consistent with the actual vehicle. The gear ring fixing mechanism is used to constrain the coaxiality between the gear ring and the motor output shaft to avoid vibration or radial offset during the rotation of the gear ring.

[0026] Using gear ring parameters that are completely identical to those of the actual vehicle ensures that the sensing environment of the wheel speed sensor is perfectly matched to the actual vehicle operating conditions, avoiding signal distortion caused by differences in gear ring parameters. At the same time, the coaxiality is ensured by the gear ring fixing mechanism, which can effectively eliminate wheel speed signal interference caused by mechanical vibration and offset, and improve the realism and stability of the analog signal.

[0027] The actual vehicle's wheel speed sensor uses a Hall effect sensor identical to that of the actual vehicle. Its sensing end faces the tooth surface of the gear ring, and it outputs corresponding pulse signals by detecting changes in the tooth grooves during gear ring rotation. The collected wheel speed signals are then sent to the signal network and the ABS / ESC controller. The wheel speed sensor adjustment mechanism is fixedly connected to the mounting base of the actual vehicle's wheel speed sensor. The sensor clamp and mounting base are connected via elongated mounting holes for axial (air gap) linear displacement adjustment. The two mounting holes on the mounting base are arc-shaped slots, allowing the sensor clamp to rotate slightly around its central axis. The sensor body is held in place by elastic clamps on the clamp. The clamp and mounting base are connected by bolts, secured with high-strength locking bolts and an anti-loosening structure. Axial travel is adjustable from 0-5mm with an accuracy of ±0.1mm; yaw angle range: ±5°-±10° with an accuracy of ±0.5°; air gap is adjustable from 0-1mm. This allows for fine-tuning of the sensor's installation position, installation angle, and the air gap between the sensor and the gear ring to match the installation requirements of different vehicle models.

[0028] Using the original Hall effect wheel speed sensor from the actual vehicle, it can completely replicate the signal acquisition characteristics of the actual vehicle, ensuring the validity of the test results; through multi-dimensional fine-tuning of the wheel speed sensor adjustment mechanism, it can match the sensor installation requirements of different vehicle models, adapt to different air gap adjustment needs, and improve the versatility and compatibility of the system.

[0029] The ABS / ESC controller is the controller for the vehicle under test. Its signal input terminal is electrically connected to the signal output terminal of the actual wheel speed sensor, and its CAN communication terminal is connected to the vehicle's CAN network and the data acquisition module of the host computer. The ABS / ESC controller is used to receive the wheel speed signals collected by the actual wheel speed sensor, execute the corresponding anti-lock braking and electronic stability control algorithms, and convert the processed wheel speed signals into CAN signals and send them to the CAN network to realize CAN signal interaction.

[0030] By connecting the ABS / ESC controller of a real vehicle as the test object, it is possible to realize full-link hardware-in-the-loop testing of wheel speed sensors and vehicle active safety controllers, directly verify the impact of wheel speed signals on the control logic of active safety systems, and improve the authenticity and effectiveness of the test.

[0031] The host computer has a built-in vehicle dynamics simulation module, which can use the vehicle model provided by CarSim or a user-defined vehicle model. The host computer is used to input simulation operating condition parameters, calculate the instantaneous target wheel speed of each wheel through the vehicle dynamics simulation module, convert the target wheel speed into a control signal for the drive motor and send it to the motor controller. At the same time, the host computer collects wheel speed signals in the CAN network through a data acquisition tool, processes them and feeds them back to the vehicle dynamics simulation module to form a closed-loop simulation test circuit.

[0032] The vehicle dynamics model on the host computer allows for flexible configuration of various real-world driving conditions, including different vehicle speeds, steering angles, road surface adhesion coefficients, and other boundary conditions. This enables full-condition wheel speed simulation testing without the need to build complex real-world vehicle or test bench environments. Simultaneously, the closed-loop feedback loop allows for real-time verification of the control effect of the controller under test, enabling the identification and resolution of potential problems early in the development process. This avoids the risk of costly hardware modifications and recalls later on, significantly shortening the development cycle and reducing R&D costs.

[0033] The core control logic of this simulation system is divided into four units: signal generation, signal processing, mode switching, and test verification. The specific contents of each unit are as follows: Signal generation unit: The signal generation unit is integrated into the vehicle dynamics simulation module of the host computer. It is used to establish a vehicle motion model based on the principles of vehicle dynamics. The input parameters of the vehicle motion model include vehicle speed, acceleration, wheel radius, steering angle, and road adhesion coefficient. The output parameter is the expected wheel speed of each wheel. Based on the calculated expected wheel speed, it generates a pulse signal proportional to the wheel speed, as well as an analog signal whose amplitude and phase can be adjusted as needed.

[0034] The formula for calculating the signal frequency based on the target wheel speed is f = wheel speed × number of teeth on the signal disc / 60. The formula for calculating the number of pulses within a specific period is pulse number = wheel speed × number of teeth on the gear ring × sampling period / 60. The accuracy of the signal can be verified using the above formulas. For the simulation scenario of the magnetoelectric wheel speed sensor, the amplitude of the output sine wave signal can be adjusted from 0.5V to 5V to match the output characteristics of the actual vehicle sensor.

[0035] By using signal generation logic based on vehicle dynamics principles, the system can accurately reproduce the changing patterns of wheel speed signals during actual vehicle operation. At the same time, through standardized parameter calculation formulas, it ensures the consistency between the generated wheel speed signals and the actual vehicle conditions, providing accurate signal input for subsequent testing. It also supports the generation of pulse signals and analog signals, and can adapt to the testing needs of different types of wheel speed sensors such as Hall effect and magnetoelectric sensors, thus expanding the system's applicability.

[0036] Signal Processing Unit: The signal processing unit is integrated into the signal processing module of the ABS / ESC controller or the host computer. It is used to filter and calculate the acquired wheel speed signal to improve the accuracy and real-time performance of the wheel speed calculation and reduce interference. The specific processing logic is as follows: A second-order active Butterworth low-pass filter is used to filter the acquired wheel speed signal. The filter stopband attenuation slope is -40dB / dec. When the maximum vehicle speed is 200km / h, the corresponding wheel speed signal frequency is approximately 2kHz. Therefore, the cutoff frequency is usually set to 2kHz–5kHz to ensure signal integrity. The rising and falling edges of the sampled pulse signal are used to calculate the wheel speed. If the difference between the wheel speed calculated at the rising edge and the wheel speed calculated at the falling edge is within a preset allowable range, the average of the two is taken as the effective wheel speed for this cycle. If the difference exceeds the preset allowable range, the value closest to the effective wheel speed of the previous cycle is taken as the effective wheel speed for this cycle. To ensure wheel speed error is less than 0.5 km / h, the difference between the wheel speed at the rising edge and the wheel speed at the falling edge must be sufficiently small, ideally less than 1.0 km / h. If the difference exceeds this range, it is considered abnormal, and a value closer to the effective wheel speed of the previous cycle should be used. To guarantee accuracy and response speed across the entire vehicle speed range, the preset allowable range and judgment logic need to be adaptively adjusted according to vehicle speed. At low speeds, the wheel speed signal frequency is low, the signal period is long, and it is easily affected by gear ring eccentricity, road bumps, and sensor noise, leading to large fluctuations in the wheel speed at the rising and falling edges. To avoid frequent triggering of abnormal judgments, the allowable range can be appropriately widened, for example, set to ±1.5 km / h. The calculated value with the smallest difference from the effective wheel speed of the previous cycle should be prioritized to ensure a smooth wheel speed curve at low speeds and avoid jumps. At medium speeds, the vehicle travels relatively smoothly, and the wheel speed signal quality is good. When the difference is within the limit, the average of the wheel speed on the rising edge and the wheel speed on the falling edge is strictly used as the effective wheel speed to obtain the highest accuracy. At high speeds, the wheel speed signal frequency is high, which increases the sampling and calculation pressure on the sensors and ECU, but the wheel speed change rate is relatively low. When the difference exceeds the range, it quickly switches to a value that is closer to the effective wheel speed of the previous cycle to avoid control inaccuracy under high-speed conditions due to a single abnormal calculation.

[0037] Low-pass filtering effectively removes high-frequency interference from wheel speed signals, improving the signal-to-noise ratio. Dual-edge sampling wheel speed calculation logic significantly improves the accuracy and real-time performance of wheel speed calculation, avoiding errors caused by single-edge sampling. Furthermore, differential verification logic effectively eliminates abnormal sampling values, ensuring the stability and reliability of wheel speed calculation results.

[0038] Mode Switching Unit: The mode switching unit is integrated into the motor controller and signal processing unit. It automatically switches between low-speed and high-speed operating modes based on the frequency of the input signal to adapt to the wheel speed signal characteristics at different vehicle speeds. In low-speed mode, if the time since the last detected tooth signal exceeds a preset threshold, the signal is retransmitted. In high-speed mode, data units following the speed pulse may not be fully transmitted, but data units currently being transmitted will be transmitted completely. The switching between low-speed and high-speed modes typically uses the wheel speed signal frequency as the core threshold. When the wheel speed signal frequency f < 20Hz, the system enters low-speed mode; when f ≥ 20Hz, the system enters high-speed mode. The relationship between the wheel speed signal frequency f and the vehicle speed v, the number of teeth Z on the gear ring, and the wheel rolling radius R is as follows: In low-speed mode, the technical requirement of a steady-state error of less than 0.5 km / h is met, while also considering signal stability. The preset allowable range for the difference between the calculated values ​​of the rising and falling edges of the wheel speed signal is 1.5 km / h. Low-speed wheel speed signals have low frequency and long periods, making them susceptible to the influence of gear ring eccentricity. If the 1.0 km / h threshold of the medium-speed mode is used, abnormal judgments will be frequently triggered, resulting in an uneven wheel speed curve and affecting control accuracy. The maximum deviation between the calculated average value of the rising and falling edges of the wheel speed signal and the actual value can still be controlled within 0.75 km / h. Combined with subsequent software filtering, the final steady-state error can be further suppressed to below 0.5 km / h, avoiding frequent abnormal judgments caused by noise and ensuring the overall accuracy of the wheel speed signal under low-speed conditions, meeting the basic requirements of safety systems such as ABS / ESC.

[0039] By automatically switching between high and low speed modes, it can adapt to the wheel speed simulation needs of the entire vehicle speed range from low-speed crawling to high-speed driving, avoiding the problems of signal loss under low-speed conditions and signal congestion under high-speed conditions, and ensuring the accuracy and continuity of wheel speed signal simulation in the entire vehicle speed range.

[0040] Test and verification unit: The test and verification unit is integrated into the host computer and is used to monitor and verify the entire simulation test process and complete the test and verification of the wheel speed signal.

[0041] The test and verification unit enables full traceability of the simulation testing process, while significantly improving test repeatability, facilitating automated regression testing and performance optimization, and further enhancing product development efficiency.

[0042] II. Hardware-in-the-Loop Simulation Method for Wheel Speed ​​Sensors This embodiment also provides a hardware-in-the-loop simulation method for wheel speed sensors. This method is based on the above-mentioned hardware-in-the-loop simulation system for wheel speed sensors and specifically includes the following steps: Step S1: Simulation Condition Configuration and Target Wheel Speed ​​Calculation. In the vehicle dynamics simulation module of the host computer, select the CarSim built-in vehicle model or a custom vehicle model, and input the simulation condition parameters, including vehicle speed, steering angle, road adhesion coefficient, number of teeth on the gear ring, and wheel rolling radius. Based on the input parameters and the principles of vehicle dynamics, the vehicle dynamics simulation module calculates the instantaneous target wheel speed of each wheel, with the unit of the target wheel speed being m / s.

[0043] By flexibly configuring simulation parameters, various real-vehicle driving conditions can be quickly reproduced. Wheel speed simulation tests in different scenarios can be achieved without building a complex real-vehicle environment, significantly reducing the cost and time required to build the test environment.

[0044] Step S2: Motor control signal conversion and transmission. The host computer converts the calculated target wheel speed into a control signal for the drive motor, and sends the control signal to the motor driver through the slave computer. The motor driver calculates the phase sequence, phase voltage, and other drive parameters of the motor based on the received control signal, and drives the motor to perform rotational actions according to the speed, direction, and acceleration corresponding to the target wheel speed.

[0045] Through standardized signal conversion and drive control, the target wheel speed of the digital simulation model can be accurately converted into the physical rotation of the motor, realizing real-time linkage between digital simulation and hardware execution, and ensuring the dynamic response accuracy of wheel speed simulation.

[0046] Step S3: Rotation of the actual vehicle gear ring and acquisition of wheel speed signals. The motor drives the actual vehicle gear ring to rotate coaxially through the gear ring fixing mechanism, replicating the rotation process of the actual vehicle wheel; the actual vehicle wheel speed sensor acquires the simulated wheel speed signal by detecting the changes in the tooth grooves during the rotation of the gear ring, and sends the simulated wheel speed signal to the ABS / ESC controller. In this step, the installation position, installation angle, and air gap between the actual vehicle wheel speed sensor and the gear ring can be adjusted through the wheel speed sensor adjustment mechanism to match the installation requirements of different vehicle models.

[0047] By combining the actual vehicle gear ring with the actual vehicle wheel speed sensor, the wheel speed signal acquisition environment of the actual vehicle can be completely replicated, ensuring that the acquired simulated wheel speed signal is completely consistent with the actual vehicle operating conditions, thus improving the authenticity and validity of the test results. At the same time, through the adjustable air gap design, the performance of the wheel speed sensor under different installation conditions can be verified, thereby improving the coverage of the test.

[0048] Step S4: Controller signal processing and CAN signal interaction. The ABS / ESC controller receives the simulated wheel speed signal sent by the actual wheel speed sensor, executes the corresponding anti-lock braking and electronic stability control algorithms, and at the same time converts the simulated wheel speed signal into a CAN signal and sends it to the vehicle's CAN network.

[0049] By connecting to the actual vehicle's ABS / ESC controller, it is possible to perform end-to-end testing from wheel speed sensors to active safety controllers, directly verifying the impact of wheel speed signals on the control logic of the vehicle's active safety system, and achieving true hardware-in-the-loop closed-loop testing.

[0050] Step S5: Closed-loop feedback and simulation iteration. The host computer collects wheel speed signals from the CAN network using a data acquisition tool. After processing the collected signals, the signals are fed back to the vehicle dynamics simulation module. Based on the feedback wheel speed signals, the vehicle dynamics simulation module updates the state parameters of the vehicle motion model, and then updates the target wheel speed, completing one closed-loop simulation iteration.

[0051] Through the closed-loop feedback loop, the control effect of the controller under test can be verified in real time, realizing dynamic iteration of the simulation conditions, completely replicating the closed-loop control logic in the actual vehicle driving process, and further improving the realism of the test; at the same time, the vehicle model can be quickly adjusted according to the vehicle model changes, realizing rapid adaptation testing of multiple vehicle models.

[0052] III. Hardware-in-the-Loop Testing Examples In a preferred hardware-in-the-loop (HIL) test embodiment, the controller under test is connected to the relevant channels of the HIL cabinet, including electrical and ground connections, I / O signal connections, bus signal connections, etc. In order to make the wheel speed simulation closer to the actual situation, the simulation system of this embodiment is used to output the simulated wheel speed signal.

[0053] The simulation model inputs the target operating condition model signal and inputs necessary parameters, such as the number of gear teeth and rolling radius, into the simulator control quantity calculation. Through the simulator control quantity calculation in the model, the signal frequency is determined according to the target wheel speed, and the signal amplitude and phase are adjusted to match the actual characteristics. At the same time, the number of pulses within a specific period is calculated to verify the signal accuracy. Finally, the direction level and speed FM required by the servo drive are generated, so that the servo drive works according to the simulated operating condition and controls the servo motor. The servo motor provides angular velocity to the actual vehicle gear ring according to the phase sequence and phase voltage provided by the servo drive. At the same time, the actual vehicle wheel speed sensor collects and generates simulated wheel speed signals based on the installation angle and air gap matched with the actual vehicle gear ring and outputs them to the ECU under test. The ECU under test adjusts the control simulation model according to the real-time situation or parameter changes, thus forming a closed loop, and can quickly adjust the model according to changes in vehicle model.

[0054] This preferred embodiment can achieve independent simulation of the wheel speed of four wheels of a real vehicle, with adjustable air gap. The steady-state error of the simulated wheel speed signal is less than 0.5 km / h, and the maximum transient error of the simulated wheel speed signal is no greater than 1 km / h. It supports forward and reverse wheel speed simulation and can collect simulated wheel speed signals.

[0055] This preferred embodiment can be directly adapted to standard HIL test cabinets to achieve fully automated hardware-in-the-loop testing. It has high wheel speed simulation accuracy and fast response speed, and can cover the wheel speed testing requirements of real vehicles under all working conditions. It can significantly improve the development and testing efficiency of wheel speed sensors and vehicle active safety systems, shorten the development cycle, reduce R&D costs, and at the same time, it can discover and solve potential problems in the early stage of development, avoiding the risks of later hardware modifications and product recalls.

[0056] It should be noted that, in this invention, although the specification describes the embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A wheel speed sensor hardware-in-the-loop simulation system, comprising a host computer and a wheel speed simulator, the host computer being built-in with a vehicle dynamics simulation module, the wheel speed simulator comprising a motor and a motor controller, the motor controller being in communication connection with the host computer for driving the motor to operate, characterized in that, It also includes a real vehicle gear ring and a real vehicle wheel speed sensor. The wheel speed simulator also includes a gear ring fixing mechanism, a wheel speed sensor adjustment mechanism, and an ABS / ESC controller. The gear ring fixing mechanism is connected to the output shaft of the motor for coaxially fixing the actual gear ring, so as to drive the actual gear ring to rotate synchronously with the motor; The wheel speed sensor adjustment mechanism is used to fix the actual wheel speed sensor and adjust the relative position between the actual wheel speed sensor and the actual vehicle gear ring. The signal output terminal of the actual vehicle wheel speed sensor is electrically connected to the ABS / ESC controller, and is used to collect the wheel speed signal generated during the rotation of the actual vehicle gear ring, and send the wheel speed signal to the ABS / ESC controller; The ABS / ESC controller is communicatively connected to the host computer and is used to receive the wheel speed signal and execute the corresponding vehicle control algorithm, while feeding back the processed wheel speed signal to the host computer. The host computer is also used to update the state parameters of the vehicle dynamics simulation module based on the feedback wheel speed signal, forming a closed-loop simulation test circuit.

2. The wheel speed sensor hardware-in-the-loop simulation system of claim 1, wherein, The motor is a servo motor, and the wheel speed, steering and acceleration of the motor are all precisely controlled in a closed loop by the motor controller; The motor controller includes a lower-level machine and a servo driver. The input terminal of the lower-level machine is communicatively connected to the upper-level machine, and the output terminal is electrically connected to the control terminal of the servo driver. The power output terminal of the servo driver is electrically connected to the power supply terminal of the motor, and is used to drive the motor to operate according to the control commands forwarded by the lower-level machine.

3. The wheel speed sensor hardware-in-the-loop simulation system according to claim 1, characterized in that, The gear ring fixing mechanism is used to constrain the coaxiality of the actual vehicle gear ring and the motor output shaft, and to suppress vibration and radial displacement during the rotation of the actual vehicle gear ring. The wheel speed sensor adjustment mechanism is used to adjust the installation position, installation angle, and air gap between the actual wheel speed sensor and the actual vehicle gear ring to match the installation requirements of different vehicle models. The actual vehicle wheel speed sensor is a Hall effect wheel speed sensor that matches the parameters of the actual vehicle being tested.

4. The wheel speed sensor hardware-in-the-loop simulation system according to claim 1, characterized in that, The ABS / ESC controller is connected to the host computer via the vehicle's CAN network. It is used to convert the received wheel speed signals into CAN signals and upload them to the vehicle's CAN network for the host computer to collect. The host computer's vehicle dynamics simulation module supports CarSim's built-in vehicle models or user-defined vehicle models, and is used to calculate the instantaneous target wheel speed of each wheel based on the input simulation condition parameters.

5. The wheel speed sensor hardware-in-the-loop simulation system according to claim 1, characterized in that, It also includes a signal generation unit and a signal processing unit; The signal generation unit is integrated into the vehicle dynamics simulation module of the host computer. It is used to establish a vehicle motion model based on the vehicle dynamics principle, calculate the expected wheel speed of each wheel based on the input parameters, and generate pulse signals or analog signals corresponding to the wheel speed. The signal processing unit is integrated into the ABS / ESC controller or host computer and is used to filter and calculate the wheel speed of the collected wheel speed signal to obtain the effective wheel speed.

6. The wheel speed sensor hardware-in-the-loop simulation system according to claim 5, characterized in that, The signal processing unit uses a low-pass filter to filter the wheel speed signal, and simultaneously calculates the wheel speed at the rising and falling edges of the sampled pulse signal. If the difference between the wheel speed calculated at the rising edge and the wheel speed calculated at the falling edge is within the preset allowable range, then the average of the two is taken as the effective wheel speed for this cycle. If the difference between the two exceeds the preset allowable range, the value that is closer to the effective wheel speed of the previous cycle will be taken as the effective wheel speed of the current cycle.

7. A hardware-in-the-loop simulation method for a wheel speed sensor, characterized in that, The implementation of the wheel speed sensor hardware-in-the-loop simulation system based on any one of claims 1-6 includes the following steps: S1: The host computer calculates the instantaneous target wheel speed of each wheel based on the input simulation parameters through the vehicle dynamics simulation module, and sends the corresponding control commands to the motor controller. S2: The motor controller drives the motor to run according to the received control command, and drives the actual vehicle gear ring to rotate coaxially with the motor through the gear ring fixing mechanism; S3: The actual vehicle wheel speed sensor collects the wheel speed signal corresponding to the rotation of the actual vehicle gear ring and sends the wheel speed signal to the ABS / ESC controller; S4: The ABS / ESC controller receives wheel speed signals and executes the corresponding vehicle control algorithm, while feeding back the processed wheel speed signals to the host computer. S5: The host computer updates the state parameters of the vehicle dynamics simulation module based on the feedback wheel speed signal, completing one closed-loop simulation iteration.

8. The wheel speed sensor hardware-in-the-loop simulation method according to claim 7, characterized in that, In step S1, the simulation parameters include vehicle speed, steering angle, road adhesion coefficient, number of teeth on the gear ring, and wheel rolling radius; In step S2, the motor controller converts the target wheel speed into the phase sequence and phase voltage driving parameters of the motor, and drives the motor to perform rotational actions according to the speed, direction and acceleration corresponding to the target wheel speed; In step S3, the installation position, installation angle, and air gap between the actual vehicle wheel speed sensor and the actual vehicle gear ring are adjusted by the wheel speed sensor adjustment mechanism to match the installation requirements of different vehicle models. In step S4, the ABS / ESC controller converts the wheel speed signal into a CAN signal and sends it to the vehicle's CAN network for acquisition by the host computer.

9. The wheel speed sensor hardware-in-the-loop simulation method according to claim 7, characterized in that, The method also includes signal generation and signal processing steps: The signal generation steps are as follows: establish a vehicle motion model based on the principles of vehicle dynamics, calculate the expected wheel speed of each wheel based on the input parameters, and generate a pulse signal or analog signal corresponding to the wheel speed. The signal processing steps are as follows: a low-pass filter is used to filter the acquired wheel speed signal. At the same time, the wheel speed is calculated at the rising and falling edges of the sampling pulse signal. If the difference between the wheel speed calculated at the rising edge and the wheel speed calculated at the falling edge is within a preset allowable range, the average of the two is taken as the effective wheel speed of the current cycle. If the difference exceeds the preset allowable range, the value that is closer to the effective wheel speed of the previous cycle is taken as the effective wheel speed of the current cycle.

10. The wheel speed sensor hardware-in-the-loop simulation method according to claim 7, characterized in that, The method also includes mode switching and test verification steps: The mode switching steps are to automatically switch between low-speed operation mode and high-speed operation mode according to the frequency of the input signal to adapt to the wheel speed signal characteristics at different vehicle speeds. In low-speed operation mode, if the time since the last detection of the tooth signal exceeds a preset threshold, the corresponding signal is retransmitted. In high-speed operation mode, non-essential data units after the speed pulse may not be fully transmitted, while data units being transmitted are transmitted in full. The testing and verification steps involve monitoring and verifying the entire simulation testing process.

Images