Electric control suspension vehicle bench durability test method and system based on current playback

Abstract

The application relates to the technical field of test equipment, and discloses a current playback-based durability test method and system for an electric control suspension vehicle bench, which comprises an MTS system, a simulation driving system and a current sensor; a first PID controller is arranged in the MTS system; a second PID controller, a signal processing board, a PWM wave calculation model and a CDC driving valve are arranged in the simulation driving system; the CDC driving valve is connected with a shock absorber of the electric control suspension to be tested in a signal mode; the current sensor is used for collecting current data of the shock absorber; the MTS system is used for outputting a command signal to the simulation driving system and receiving the current data of the shock absorber, so as to form a control loop; the simulation driving system is used for outputting simulated current to the shock absorber according to the command signal; in the control loop, a theoretical current is calculated by the PWM wave calculation model; and the first PID controller and the second PID controller operate in parallel. The application can efficiently and accurately reproduce the current of the CDC shock absorber when the suspension works, and the test stability and reliability are good.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, and specifically to a method and system for endurance testing of an electronically controlled suspension vehicle bench based on current playback. Background Technology

[0002] With the continuous advancement of vehicle chassis technology and electronic information technology, electronically controlled suspension systems are being used more and more widely in vehicles. An electronically controlled suspension system is an advanced vehicle suspension system that, based on signals such as vehicle height, speed, steering angle and rate, and braking, is controlled by an electronic control unit (ECU) to adjust parameters such as suspension stiffness, shock absorber damping force, and vehicle height. This allows for adaptation to different driving conditions and vehicle loads, thereby improving vehicle performance, comfort, and safety.

[0003] Against this backdrop, the quality of electronically controlled suspension systems has become a key focus of the industry. Furthermore, electronically controlled suspension systems generally consist of electronic control units, elastic elements, guiding mechanisms, shock absorbers, and other components. Due to the unique structural characteristics of electronically controlled suspension systems, accurate testing requires replicating the CDC shock absorber (hereinafter referred to as shock absorber) current during system operation to ensure accurate reproduction of the target damping.

[0004] However, most existing vehicle durability testing methods cannot meet the testing requirements of electronically controlled suspension systems. There are two main reasons: (1) The valve clearance of the shock absorbers in current electronically controlled suspension systems is controlled by the magnitude of the current, which changes in real time according to the vehicle's condition. Traditional bench testing methods can only simulate the road surface's excitation of the vehicle, but cannot simulate the current control situation, thus failing to guarantee the accuracy of the shock absorber's damping force and failing to reproduce the real vehicle's stress conditions; (2) The magnitude of the shock absorber current in electronically controlled suspension is obtained by the electronically controlled suspension system through algorithmic logic based on signals such as vehicle height, vehicle speed, steering angle and rate, and braking. However, during vehicle durability testing, the durability bench system cannot simulate signals such as vehicle height, vehicle speed, steering angle and rate, and braking, resulting in the inability to obtain the shock absorber current of the electronically controlled suspension. These two factors lead to low accuracy and poor reliability in existing durability bench tests. Summary of the Invention

[0005] The present invention aims to provide a vehicle bench durability test method and system for electronically controlled suspension based on current playback, which can efficiently and accurately reproduce the current of the CDC shock absorber when the suspension is working, and has good test stability and reliability.

[0006] To achieve the above objectives, the basic solution provided by this invention is as follows:

[0007] Option 1

[0008] The vehicle bench durability testing system for electronically controlled suspension based on current playback includes an MTS system, a simulation drive system, and a current sensor; the MTS system establishes signal connections with the simulation drive system and the current sensor.

[0009] The MTS system includes a first PID controller; the simulation drive system includes a second PID controller, a signal processing board, a PWM wave calculation model, and a CDC drive valve; the CDC drive valve establishes a signal connection with the shock absorber of the electronically controlled suspension under test; the current sensor is used to collect the current data of the shock absorber; the MTS system is used to output command signals to the simulation drive system and receive the current data of the shock absorber to form a control loop; the simulation drive system is used to output simulated current to the shock absorber according to the command signals.

[0010] In the control loop, the theoretical current is calculated by the PWM wave calculation model; the required current command signal is obtained by the first PID controller based on the command signal and the current data of the shock absorber; the required analog current is obtained by the second PID controller based on the theoretical current and the current data of the CDC drive valve; and the first PID controller and the second PID controller operate in parallel.

[0011] Option 2

[0012] The method for endurance testing of electronically controlled suspension on a vehicle bench based on current playback uses the endurance testing system for electronically controlled suspension based on current playback as described in Scheme 1, and includes the following steps:

[0013] Step 1: Pre-store the road spectrum acquisition current in the MTS system. The road spectrum acquisition current is the shock absorber current signal data collected from the actual vehicle.

[0014] Step 2, run the control loop; the MTS system outputs a command signal to the simulation drive system, the simulation drive system outputs a simulated current to the shock absorber based on the command signal, and the MTS system receives the current data of the shock absorber;

[0015] Step 3: If the current data of the shock absorber does not reach the current size of the road spectrum acquisition, the MTS system adjusts the command signal and repeats step 2 until the error between the current data of the shock absorber and the current of the road spectrum acquisition is kept within the preset range.

[0016] The working principle and advantages of this invention are as follows:

[0017] In this solution, the MTS system, simulation drive system, and current sensor work in conjunction with the shock absorber of the electronically controlled suspension under test to form a complete control loop. This loop provides the shock absorber with accurate and realistic current signals to drive its operation and reproduce the target damping, thereby replicating the actual working conditions of the suspension. This facilitates the execution of vehicle-mounted bench durability tests on the electronically controlled suspension. The simulation drive system outputs a stable simulated current to the shock absorber based on the theoretical current calculated by the PWM wave calculation model, effectively solving the problem of difficulty in reproducing road loads when the shock absorber is not driven. Furthermore, during durability testing, the MTS system iterates and optimizes the command signal based on feedback information from the shock absorber, obtaining a highly realistic current command signal that allows the shock absorber to reproduce real operating conditions.

[0018] Notably, this solution employs a dual PID control strategy, comprising a first PID controller within the MTS system and a second PID controller within the simulation drive system. During command signal iteration, the first PID controller adjusts the command signal based on real-time feedback from the shock absorber; the second PID controller adjusts the analog current output by the simulation drive system based on real-time feedback from the CDC drive valve. The former adjusts signal error from the front end using end feedback, while the latter adjusts signal error promptly at the mid-end using mid-range feedback. Together, they can rapidly acquire the target command signal and achieve the target current value (ensuring the error between the shock absorber's current data and the current collected from the road spectrum remains within a preset range, achieving precise drive). Compared to existing testing solutions, which often only employ a single PID controller, all housed in the main controller and directly control current based on the control current and actual current, this approach, while optimizing the current signal, suffers from poor accuracy, stability, and operational efficiency. It requires numerous iterative adjustments, and when a component in the control circuit becomes unstable, the control and optimization of the current signal are easily lost.

[0019] In this solution, a dual PID control strategy is employed, where each PID controller forms a closed-loop control system, making it less prone to loss of control and ensuring stable signal output. Furthermore, under the dual PID control strategy, the MTS system and the simulation drive system can optimize the current signal from different perspectives during signal feeding, enabling faster elimination of current errors and achieving the target current value. This results in high testing efficiency, stable and reliable testing.

[0020] Furthermore, the simulation-driven system in this solution offers high flexibility, adapting to various application scenarios. Compared to existing current playback devices, where the command signal and current relationship are fixed once the current playback controller is packaged, changes in the external control system (e.g., replacing the MTS system with another system) can lead to different command signal magnitudes, potentially causing excessive current and burning out the CDC damper, impacting testing progress and posing safety risks. This solution avoids these problems. When command signals change due to control system replacement or other reasons, the parameters of the PWM wave calculation model in the simulation-driven system can be adjusted to flexibly handle different command signals, keeping the current within the CDC damper's operating current range. The system boasts greater applicability and higher reliability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the system structure of an embodiment of the electronically controlled suspension vehicle bench durability testing method and system based on current playback of the present invention;

[0022] Figure 2 This is a schematic diagram of the operation flow of the first PID controller in an embodiment of the electronically controlled suspension vehicle bench durability testing method and system based on current playback of the present invention.

[0023] Figure 3 This is a schematic diagram of the operation flow of the second PID controller in an embodiment of the electronically controlled suspension vehicle bench durability testing method and system based on current playback of the present invention.

[0024] Figure 4 This is a schematic diagram of the operation flow of the first signal adjustment unit and the second signal adjustment unit in an embodiment of the current playback-based electronically controlled suspension vehicle bench durability testing method and system of the present invention. Detailed Implementation

[0025] The following detailed explanation illustrates the specific implementation methods:

[0026] The basic implementation examples are as follows: Figure 1 As shown: A vehicle bench durability testing system for electronically controlled suspension based on current playback, including an MTS system, a simulation drive system, and a current sensor.

[0027] The MTS system establishes signal connections with the simulation drive system and the current sensor. Specifically, in this embodiment, the analog output terminal of the MTS system is connected to the analog input terminal of the simulation drive system. The current sensor is located at the shock absorber of the electronically controlled suspension under test, and is used to collect the current data of the shock absorber; simultaneously, the analog output terminal of the current sensor is connected to the analog input terminal of the MTS system.

[0028] The MTS system includes a first PID controller; the simulation drive system includes a second PID controller, a signal processing board, a PWM wave calculation model, and a CDC drive valve. Specifically, the signal processing board includes a signal conditioning board, an NI input board, and a PWM wave output board. The signal conditioning board has a signal scaling function unit; the voltage signal input range of the signal conditioning board is ±50V; it can accept a wider range of voltage signal inputs, making it more adaptable. Furthermore, the hardware used in this simulation drive system is all reliable off-the-shelf hardware, eliminating the need for additional custom-made function boards to implement this solution, resulting in good operational convenience. Compared to custom-made function boards, off-the-shelf hardware offers more stable performance, and the overall performance stability and security of this system are superior.

[0029] The CDC drive valve establishes a signal connection with the shock absorber of the electronically controlled suspension under test. In the simulation drive system, the command signal feed path is as follows: the command signal is input to the signal conditioning board, then sequentially transmitted to the NI input board, the PWM wave calculation model, the PWM wave output board, the CDC drive valve, and finally applied to the shock absorber. During this process, the signal conditioning board can amplify or reduce the signal as needed to facilitate data analysis.

[0030] The MTS system is used to output command signals to the simulation drive system and receive current data from the shock absorber to form a control loop; the simulation drive system is used to output simulated current to the shock absorber according to the command signals.

[0031] Specifically, in the control loop, the theoretical current is calculated using a PWM waveform calculation model; as shown in the attached figure. Figure 2 As shown, the first PID controller analyzes the command signal and the current data of the shock absorber to obtain the required current command signal; as attached. Figure 3 As shown, the second PID controller analyzes and obtains the required simulated current based on the theoretical current and the current data of the CDC drive valve; and the first PID controller and the second PID controller operate in parallel.

[0032] The first PID controller and the second PID controller are respectively equipped with a first signal adjustment unit and a second signal adjustment unit; the first signal adjustment unit is used to adjust the current error between the command signal and the current data of the shock absorber; the second signal adjustment unit is used to adjust the current error between the theoretical current and the current data of the CDC drive valve; the adjustment includes proportional control, integral control and derivative control, as shown in the appendix. Figure 4 As shown.

[0033] Both the first signal adjustment unit and the second signal adjustment unit adjust the current error according to the following formula:

[0034]

[0035] Where, k p For proportional adjustment coefficient, k i For integral adjustment coefficient, k d For the differential adjustment coefficient, e I This is for current error.

[0036] Specifically, k p The larger the value, the faster the system response speed, but the lower the system stability. In this embodiment, the k values ​​corresponding to the first signal adjustment unit and the second signal adjustment unit can be coordinated simultaneously. p The value, i.e., the k of the two PID controllers. p In combination, there is no need to set an excessively large k. p This value can speed up the response while ensuring system stability.

[0037] After error adjustment, the required current command signal and the required analog current are then output.

[0038] This embodiment also provides a vehicle bench durability test method for electronically controlled suspension based on current playback. The durability test is performed using the vehicle bench durability test system for electronically controlled suspension based on current playback as described in Scheme 1, and includes the following steps:

[0039] Step 1: Pre-store the road spectrum acquisition current in the MTS system. The road spectrum acquisition current is the shock absorber current signal data collected from the actual vehicle.

[0040] Specifically, when collecting current from the pre-stored road spectrum, the following steps are included: 1) removing drift and singular values ​​from the signal data; 2) adjusting the sampling frequency of the signal data to 512 Hz; 3) adjusting the number of points in each frame of the signal data to 2048; 4) converting the signal data to RSP format for easy system recognition; 5) importing the processed signal data through system software.

[0041] Step 2: Run the control loop; the MTS system outputs a command signal to the simulation drive system, the simulation drive system outputs a simulated current to the shock absorber based on the command signal, and the MTS system receives the current data of the shock absorber.

[0042] Specifically, when operating the control loop, the transfer function of the entire system (including the MTS system, the electronic control simulation system, and the test vehicle) is first solved, and the drive current is calculated based on the current collected from the road spectrum, which serves as the initial command signal (i.e., the current command signal).

[0043] The following steps are included in solving the transfer function: 1) First, give the current a white noise current command (i.e., give a white noise current command signal) and collect the current on the CDC shock absorber by the current sensor; 2) Obtain the transfer function by comparing the signal on the current sensor with the white noise current command; 3) Calculate the driving current based on the current collected from the pre-stored road spectrum and the transfer function.

[0044] Step 3: If the shock absorber's current data does not reach the magnitude of the road spectrum acquisition current, the MTS system adjusts the command signal and repeats step 2 to iterate the command signal until the error between the shock absorber's current data and the road spectrum acquisition current remains within a preset range. In this embodiment, the preset range is 1%, which achieves high control accuracy.

[0045] Step 4: Conduct a durability test. During the durability test, the final current-driven signal will be repeatedly played.

[0046] This embodiment provides a vehicle bench durability test method and system for electronically controlled suspension based on current playback, which can efficiently and accurately reproduce the working conditions of the suspension, and has good test stability and reliability.

[0047] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. An electronically controlled suspension vehicle bench durability test system based on current playback, characterized in that, The system comprises an MTS system, a simulation driving system and a current sensor; the MTS system is signal-connected with the simulation driving system and the current sensor; The MTS system is provided with a first PID controller; the simulation driving system is provided with a second PID controller, a signal processing board, a PWM wave calculation model and a CDC driving valve; the CDC driving valve is signal-connected with a shock absorber of the to-be-tested electronically controlled suspension; the current sensor is used to collect current data of the shock absorber; the MTS system is used to output a command signal to the simulation driving system and receive the current data of the shock absorber to form a control loop; the simulation driving system is used to output an analog current to the shock absorber according to the command signal; In the control loop, a theoretical current is calculated by the PWM wave calculation model; a required current command signal is analyzed by the first PID controller based on the command signal and the current data of the shock absorber; a required analog current is analyzed by the second PID controller based on the theoretical current and the current data of the CDC driving valve; and the first PID controller and the second PID controller operate in parallel; The first PID controller and the second PID controller are respectively provided with a first signal adjusting unit and a second signal adjusting unit; the first signal adjusting unit is used to adjust a current error between the command signal and the current data of the shock absorber; the second signal adjusting unit is used to adjust a current error between the theoretical current and the current data of the CDC driving valve; the adjustment comprises proportional adjustment, integral adjustment and differential adjustment; The first signal adjusting unit and the second signal adjusting unit adjust the current error according to the following formula: ； wherein, is a proportional regulation coefficient, is an integral regulation coefficient, is a derivative regulation coefficient, is a current error; When the current error is adjusted, the first signal adjustment unit and the second signal adjustment unit respectively corresponding to the first signal and the second signal are coordinated values, i.e. the values of the two PID controllers are matched.

2. The electronically controlled suspension durability test system based on current playback according to claim 1, wherein, The signal processing board comprises a signal conditioning board, an NI input board and a PWM wave output board.

3. The electronically controlled suspension durability test system based on current playback according to claim 2, characterized in that, In the simulation driving system, the feeding path of the command signal is: the command signal is input to the signal conditioning board, and then is sequentially transmitted to the NI input board, the PWM wave calculation model, the PWM wave output board, the CDC driving valve, and finally acts on the shock absorber.

4. The electronically controlled suspension durability test system based on current playback according to claim 2, wherein, The signal conditioning board is provided with a signal scaling function unit; the voltage signal input range of the signal conditioning board is .

5. The method for durability test of electronically controlled suspension vehicle bench based on current playback, characterized in that, The current playback-based electronically controlled suspension whole-vehicle bench durability test system according to any one of claims 1-4 is used for durability test, comprising the following steps: Step 1: prestore road spectrum collection current in the MTS system, wherein the road spectrum collection current is a shock absorber current signal data collected by a real vehicle; Step 2: run the control loop; output the command signal from the MTS system to the simulation driving system, output the analog current from the simulation driving system to the shock absorber based on the command signal, and receive the current data of the shock absorber by the MTS system; Step 3: if the current data of the shock absorber does not reach the size of the road spectrum collection current, adjust the command signal by the MTS system and repeat step 2 until the error between the current data of the shock absorber and the road spectrum collection current is kept within a preset range.

6. The electronically controlled suspension durability test method based on current playback according to claim 5, wherein, The preset range is 1%.

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