A temperature closed-loop control method for durability test of a shock absorber assembly

Abstract

The application belongs to the technical field of automobile parts testing, and discloses a shock absorber assembly endurance test temperature closed-loop control method and a measuring method, which comprises the following steps: collecting the internal temperature of each station shock absorber in real time; calculating the temperature rising rate of each station shock absorber; calculating the residual time and the residual time deviation of each station shock absorber reaching the target temperature; acquiring the process gain of each station in real time; calculating the water valve opening degree correction amount corresponding to each station respectively; synthesizing and outputting the final opening degree of each water valve, so that the shock absorbers of each station approach the preset target temperature synchronously and slowly; and performing water leakage and failure alarm according to whether the water valve opening degree difference and the process gain are abnormal. The application is accurate in temperature control, strong in self-adaptation, high in robustness, and stable in operation, greatly improves the test efficiency, and shortens the test time.

Description

Technical Field

[0001] This invention belongs to the field of automotive component testing technology, and relates to a method for temperature control in durability testing of electronically controlled shock absorber assemblies, specifically a closed-loop temperature control method for durability testing of shock absorber assemblies. Background Technology

[0002] In the research and development and production of vibration dampers, durability testing is a crucial step in verifying their lifespan and reliability. During the test, the internal temperature of the vibration damper continuously rises, especially in electronically controlled vibration dampers, where the repeated high-speed flow of damping oil generates a large amount of heat, leading to temperature increases. Therefore, effectively cooling the electronically controlled vibration damper and precisely controlling its temperature within the target range is a prerequisite for ensuring the accuracy and consistency of the test results.

[0003] In existing technologies, cooling is often achieved by adding an external water jacket and circulating cooling water. However, traditional control methods mostly employ simple on / off or PID control, with temperature itself as the direct control target. When multiple (e.g., four) vibration dampers are tested simultaneously, their temperature rise rates often differ due to variations in damping characteristics and heat dissipation conditions at each station. Traditional methods struggle to synchronize multiple vibration dampers and ensure they reach the same target temperature as slowly as possible, leading to inconsistent testing conditions at each station and affecting test efficiency and the comparability of results. Summary of the Invention

[0004] The present invention aims to provide a closed-loop control method for the temperature of vibration damper assembly durability testing, so as to shorten the testing time and improve the consistency of product evaluation.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A closed-loop control method for temperature during durability testing of a vibration damper assembly, comprising the following steps: S1: Real-time collection of the internal temperature of the vibration dampers at each workstation; S2: Calculate the heating rate of the vibration damper at each workstation based on its internal temperature. S3: Based on the internal temperature of the vibration damper at each workstation and the preset target temperature, calculate the remaining time and the remaining time deviation for each workstation to reach the target temperature. S4: Based on the changes in water valve opening degree and temperature rise rate, the process gain of each station is obtained in real time; S5: Taking the goal of making the remaining time of each station as consistent as possible, calculate the water valve opening correction amount corresponding to each station based on the remaining time deviation and process gain. S6: The reference opening degree is superimposed with the water valve opening correction amount of each station to synthesize and output the final opening degree of each water valve, so as to independently adjust the cooling water flow of each station and make the vibration damper of each station synchronously and slowly approach the preset target temperature. S7: Based on the difference in water valve opening and whether there is any abnormality in process gain, perform water leakage and failure alarms.

[0006] As a limitation of the present invention, in S2, the formula for calculating the heating rate of the vibration damper at each station is: ,when When the value is less than the preset lower limit of 0.02, take... =0.02; Where k is the control cycle number and i is the workstation number. This refers to the real-time temperature of the vibration dampers at each workstation. To control the cycle.

[0007] As a further limitation of the present invention, in S3, the formula for calculating the remaining time for each workstation to reach the target temperature is as follows: ,in, The preset target temperature; Calculate the average remaining time for each workstation based on the estimated remaining time to reach the target temperature: ; Calculate the remaining time deviation for each workstation to reach the target temperature: .

[0008] As another limitation of the present invention, in S4, the instantaneous gain of each station in the previous cycle is first calculated: ,in, This refers to the water valve opening degree of the previous cycle. This refers to the water valve opening degree for the first two cycles; The current process gain is updated using a smoothing filter: +0.5 ; Initial water valve opening Both are 50%, the initial value of the gain. It is 0.05; if Then the gain Keep the value from the previous period.

[0009] As a limitation of the present invention, in S5, the formula for calculating the water valve opening correction amount corresponding to each workstation is as follows: ,in, The basic proportionality coefficient is initially set at 0.01 and is adaptively adjusted during the experiment. right Limiting the amplitude: , The correction amount is limited to the range Inside, a positive value indicates that the water valve is opened wide, and a negative value indicates that the water valve is closed narrowly. This is the preset maximum adjustment range, which is 10%.

[0010] As a further limitation of the present invention, the basic proportionality coefficient Adaptive adjustment method: Calculate the oscillation index: Calculate the remaining time deviation for each workstation during these five cycles. The number of sign changes is taken as the average of the four workstations. , Calculate the average absolute deviation over the most recent five periods: , Adjustment rules: like >1.5, then ; like <1.5, and >5, and currently Compared to the previous five-cycle decline of less than 10%, ; otherwise, Remain unchanged; The initial value is 0.01, and the amplitude is limited to (0.001, 1).

[0011] As a further limitation of the present invention, in S6, the reference opening degree is calculated: ,in, Limit to .

[0012] As a further limitation of the present invention, in S6, the final opening degree of each water valve is calculated: ; Will Limit to The output is then sent to the corresponding water valve actuator.

[0013] As a third limitation of the present invention, in S7, if the difference in the opening degree of the water valve at each station exceeds the limit, and / or the process gain remains too low, it is determined that the cooling has failed / leaked water, and an alarm is triggered.

[0014] By adopting the above technical solution, the beneficial effects achieved by the present invention compared with the prior art are as follows: (1) The present invention takes the remaining time for each station to reach the target temperature as the control target. By calculating the temperature rise rate, remaining time and remaining time deviation in real time, the water valve opening correction amount of each station is dynamically allocated so that the vibration dampers of multiple stations can approach the target temperature synchronously and slowly. This ensures that the heating process of each vibration damper is consistent with the test conditions, improves the comparability and credibility of the durability test, increases the test efficiency, and shortens the test time. (2) This invention utilizes the temperature rise rate response generated by the natural change of the water valve opening during the test to identify the process gain of each station in real time online. It does not require additional step test or interrupt the durability test process. It can automatically track the time-varying characteristics of the system, adapt to different specifications of vibration dampers and different test conditions, and has stronger control robustness. (3) The basic proportional coefficient of the present invention is automatically adjusted according to the number of deviation oscillations and the convergence speed. If the oscillation is too large, the coefficient is reduced to avoid overshoot. If the convergence is too slow, the coefficient is increased to speed up the response. No manual parameter tuning is required throughout the process, reducing the dependence on the operator's experience and significantly improving the system's versatility and ease of use. (4) The present invention limits the correction amount and the final opening to avoid sudden changes and frequent oscillations of the water valve, making the cooling water flow regulation smoother and the temperature fluctuation smaller, effectively protecting the cooling system; (5) This invention achieves dual leakage / cooling failure alarm by monitoring the difference in water valve opening at each station exceeding the limit and the process gain being continuously too low, effectively ensuring test safety and equipment safety.

[0015] In summary, this invention offers precise temperature control, strong adaptability, high robustness, and stable operation, significantly improving testing efficiency and shortening testing time. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] Figure 1 This is a flowchart of Embodiment 1 of the present invention. Detailed Implementation

[0018] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and do not constitute a limitation thereof.

[0019] The use of terms such as "up" and "down" or positional relationships in the embodiments is based on the human body's position when using this embodiment. It is only for the purpose of describing the present invention and simplifying the description, and does not indicate or imply that the device or component must have a specific position, or that it is constructed and operated in a specific position. Therefore, it should not be construed as a limitation on the content protected by the present invention.

[0020] Example 1 like Figure 1As shown, this embodiment presents a closed-loop temperature control method for a vibration damper assembly durability test. This method is used to cool and control the vibration damper during the durability test, ensuring that the vibration damper temperature does not exceed a preset target temperature throughout the entire test. The preset target temperature is the highest permissible limit temperature of the vibration damper during the durability test. To ensure that the test evaluates the vibration damper within the set temperature range, the vibration damper temperature must not exceed this limit temperature during the test; if the temperature exceeds the limit, the vibration damper may be damaged or rendered unusable, and the test must be interrupted.

[0021] To shorten the test cycle and improve test efficiency, the vibration damper temperature should be kept within a safe range or as close as possible to the limit temperature. At the same time, to ensure the consistency of the assessment and the comparability of the results of the multi-station durability test, the temperature rise history of multiple vibration dampers should be kept synchronized, that is, they should reach similar temperature levels within the same time.

[0022] Therefore, this embodiment uses cooling water to cool the vibration dampers. The temperature control logic in this embodiment is as follows: when the remaining time to reach the target temperature is less than the average (i.e., the temperature rises too quickly), the controller outputs a command to increase the opening of the water valve at that station to enhance cooling and slow down the temperature rise; when the remaining time to reach the target temperature is greater than the average (i.e., the temperature rises too slowly), the controller outputs a command to decrease the opening of the water valve to weaken cooling and accelerate the temperature rise. The logic for controlling product performance consistency in this embodiment is as follows: taking the remaining time to reach the target temperature at each station as the control objective, the cooling flow rate and cooling rate are dynamically controlled by independently adjusting the opening of the water valve at each station, so that multiple vibration dampers approach the target temperature synchronously, slowly, and uniformly, thereby achieving multi-station temperature coordination, stability, and safe closed-loop control.

[0023] The first layer of control in this embodiment is quantitative control logic, which determines the specific opening degree of the water valve at each station. Specifically, based on the dynamic information of the temperature of the four vibration dampers and the opening degree of the four water valves, the internal algorithm of the controller dynamically adjusts the opening degree of each water valve in real time. The goal is to make the four vibration dampers reach the target temperature as slowly and simultaneously as possible. This ensures that the evaluation of the four vibration dampers is the same, and also improves the test efficiency.

[0024] The second layer of control in this embodiment is to output alarm information for protection and timely detection of problems. Specifically, it monitors the opening degree of the water valves at each workstation. If the difference between the maximum and minimum opening degree exceeds a preset threshold and the duration exceeds a preset time, an alarm is issued and the cooling water is shut off. This indicates an abnormal test operation, usually due to two situations: excessive damping change in the vibration damper or water leakage. Monitoring the process gain, if the gain at a certain workstation remains below a preset minimum threshold, an alarm is issued and the cooling water is shut off. This indicates a cooling system failure, possibly due to water leakage. An alarm is triggered if either or both of these abnormalities occur.

[0025] The following section details the temperature closed-loop control method of the controller.

[0026] S1: Data Acquisition The internal temperature of the vibration dampers at each workstation is collected in real time and recorded as follows: k is the control cycle number, i is the workstation number, and the control cycle is the temperature sampling interval. For example, sampling is performed once every 1 second, and the control cycle k = 1, 2, 3, 4...

[0027] S2: Data Preprocessing Calculate the heating rate of the vibration damper at each workstation based on its internal temperature. The calculation formula is: ,Will The lower limit is set to 0.02, when When the value is less than the preset lower limit of 0.02, to prevent the situation in step 3... The denominator is too small, leading to a division by zero error. =0.02.

[0028] S3: Calculate the remaining time and remaining time deviation. Based on the internal temperature of the vibration damper at each workstation and its preset target temperature, calculate the remaining time for each workstation to reach the target temperature. The calculation formula is: ,in, The preset target temperature; Calculate the average remaining time for each workstation: ; Calculate the remaining time deviation for each workstation to reach the target temperature: .

[0029] S4: Online Gain Acquisition During the test run, the process gain Gi of each station was obtained in real time by utilizing the temperature rise rate response generated by the natural change in the water valve opening.

[0030] Based on the water valve opening degree of the previous cycle Temperature rise rate The water valve opening degree in the first two cycles Temperature rise rate Calculate the instantaneous gain of the previous cycle. The calculation formula is: ; The current process gain is updated using a smoothing filter: +0.5 ; Initial water valve opening Both are 50%, the initial value of the gain. It is 0.05.

[0031] if Then the gain Keep the value from the previous period.

[0032] S5: Calculate the correction amount for the water valve opening at each workstation. With the goal of ensuring that the remaining time at each workstation is consistent, the correction amount for the water valve opening at each workstation is calculated based on the deviation of the remaining time at each workstation and the process gain. The calculation formula is as follows: ; in, The basic proportionality coefficient is initially set at 0.01 and is adaptively adjusted according to the actual situation during the experiment.

[0033] To prevent sudden changes in the water valve that could affect the rate of temperature rise, Limiting the amplitude: , That is, the correction amount is limited to the range. Inside, a positive value indicates that the water valve is opened wide, and a negative value indicates that the water valve is closed narrowly. This is the preset maximum adjustment range, set to 10%.

[0034] Basic proportional coefficient The adaptive adjustment method is as follows: The base scaling factor is adaptively adjusted based on the convergence rate and oscillation of the remaining time deviation. .

[0035] Calculate the oscillation index: Calculate the remaining time deviation for each workstation during these five cycles. The number of sign changes is taken as the average of the four workstations. , Calculate the average absolute deviation over the most recent five periods: , Adjustment rules: like A value greater than 1.5 indicates repeated oscillations and excessive sensitivity, requiring adjustment. Turn it down, then ; like <1.5, and >5, and currently Compared to the previous five-cycle decline of less than 10%, this indicates insufficient sensitivity and requires adjustment. Increase it, then ; otherwise, Remain unchanged; The initial value is 0.01, and the amplitude is limited to (0.001, 1).

[0036] S6: Determine the reference opening degree of the water valve The reference opening is superimposed with the correction amount of the water valve opening at each station to synthesize and output the final opening of each water valve, so as to independently adjust the cooling water flow of each station and make the vibration damper of each station synchronously and slowly approach the preset target temperature.

[0037] Determine the baseline opening based on the maximum correction value for each workstation: ; in, Limit to ; Calculate the final opening degree of each water valve: ; Will Limit to The output is then sent to the corresponding water valve actuator.

[0038] S7: Based on differences in water valve opening and abnormal process gain, trigger leakage and failure alarms, monitoring two parameters: water valve opening. and process gain An alarm will be issued if any one of the parameters is abnormal.

[0039] Monitor the opening degree of water valves at each workstation If the difference between the maximum and minimum opening of all water valves exceeds a preset threshold of 30% and the duration exceeds a preset time of 10 seconds, an alarm will be triggered and the cooling water will be shut off. This indicates an abnormal test operation, which usually falls into two categories: excessive damping change in the vibration damper or water leakage.

[0040] Monitoring process gain If the gain of a certain workstation falls below the preset minimum threshold of 0.005 and the duration exceeds the preset duration of 10 seconds, an alarm will be triggered and the cooling water will be shut off. This indicates a cooling system failure, most likely due to a water leak.

[0041] Example 2 This embodiment provides a specific case study in an experimental process.

[0042] Configure initial parameters: target temperature =80℃; Control cycle =1s (determined by the sampling frequency; in this case, the sampling frequency is 1Hz).

[0043] Period 0 (Initial) temperature: (At the start of operation, the vibration damper is at room temperature). Water valve opening: ; Temperature rise rate: ; Gain: ; Basic scaling factor: .

[0044] I. First Cycle 1.1 Temperature sampling (unit: °C)

[0045] 1.2 Calculation of temperature rise rate

[0046] 1.3 Calculate the remaining time (in seconds) for the four workstations. ; ; ; .

[0047] Calculate the average remaining time (in seconds) for the four workstations.

[0048] 1.4 Calculate the remaining time deviation (in seconds) ; ; ; .

[0049] 1.5 Update gain (no historical opening changes, keep initial value)

[0050] 1.6 Calculate the opening correction amount for the four station water valves. ; ; ;

[0051] Due to the limitation to ±10%: , , ,

[0052] 1.7 Determine the reference opening degree

[0053] 1.8 Calculate the water valve opening degree ; ; ; .

[0054] First cycle output water valve opening:

[0055] II. Second Period 2.1 Temperature sampling

[0056] 2.2 Calculation of temperature rise rate

[0057] 2.3 Calculate the remaining time (in seconds) for the four workstations. ; ; ;

[0058] Calculate the average remaining time (in seconds) for the four workstations.

[0059] 2.4 Calculate the remaining time deviation (in seconds) ; ; ; .

[0060] 2.5 Update gain (from cycle 0 to cycle 1) ; ; ; .

[0061] The current process gain is updated using a smoothing filter: ; ; ; .

[0062] 2.6 Calculate the opening correction amount for the four station water valves. ; ; ; .

[0063] Limit to ±10% , , ,

[0064] 2.7 Determine the reference opening degree

[0065] 2.8 Calculate the water valve opening degree ; ; ; .

[0066] Second cycle output water valve opening

[0067] III. The 3rd cycle 3.1 Temperature sampling

[0068] 3.2 Calculate the temperature rise rate

[0069] 3.3 Calculate the remaining time (in seconds) for the four workstations. ; ; ; .

[0070] Calculate the average remaining time (in seconds) for the four workstations.

[0071] 3.4 Calculate the remaining time deviation (in seconds) ; ; ; .

[0072] 3.5 Update gain (from cycle 1 to cycle 2) Since the water valve openings at workstations 1 and 2 remain unchanged, only workstations 3 and 4 need to be updated.

[0073] ; .

[0074] The current process gain is updated using a smoothing filter: ; ; ; .

[0075] 3.6 Calculate the opening correction amount for the four station water valves. ; ; ; .

[0076] Limit to ±10% , , , .

[0077] 3.7 Determine the reference opening degree

[0078] 3.8 Calculate the water valve opening degree ; ; ; .

[0079] 3rd cycle output water valve opening: .

[0080] IV. The 4th cycle 4.1 Temperature sampling

[0081] 4.2 Calculate the temperature rise rate

[0082] 4.3 Calculate the remaining time (in seconds) for the four workstations. ; ; ; .

[0083] Calculate the average remaining time (in seconds) for the four workstations:

[0084] 4.4 Calculate the remaining time deviation (in seconds) ; ; ; .

[0085] 4.5 Update gain (from cycle 2 to cycle 3) Since the water valve opening at station 3 remains unchanged, only station 1, station 2, and station 4 need to be updated.

[0086] ; ; .

[0087] The current process gain is updated using a smoothing filter: ; ; ;

[0088] .

[0089] 4.6 Calculate the opening correction amount for the four station water valves. ; ; ; .

[0090] Limit to ±10% , , , .

[0091] 4.7 Determine the reference opening degree

[0092] 4.8 Calculate the water valve opening degree ; ; ; .

[0093] 4th cycle output water valve opening: .

[0094] V. The 5th cycle 5.1 Temperature sampling

[0095] 5.2 Calculate the temperature rise rate

[0096] 5.3 Calculate the remaining time (in seconds) for the four workstations. ; ; ; .

[0097] Calculate the average remaining time (in seconds) for the four workstations:

[0098] 5.4 Calculate the remaining time deviation (in seconds) ; ; ; ; .

[0099] 5.5 Update Gain (from cycle 3 to cycle 4) ; ; ; .

[0100] The current process gain is updated using a smoothing filter: ; ; ; .

[0101] 5.6 Calculate the opening correction amount for the four station water valves. ; ; ; .

[0102] Limit to ±10% , , ,

[0103] 5.7 Determine the reference opening degree

[0104] 5.8 Calculate the water valve opening degree ; ; ; .

[0105] 5th cycle output water valve opening: .

[0106] VI. Adaptive Adjustment of Basic Proportion Coefficient Table 1 Summary of Deviation Sign and Number of Changes for Each Period

[0107] Count the number of symbol changes between adjacent cycles for each workstation: Workstation 1: 1→2 (- unchanged), 2→3 (- changes to +) once, 3→4 (+ unchanged), 4→5 (+ changes to -) once: a total of 2 times; Workstation 2: 1→2 (+ remains unchanged), 2→3 (+ remains unchanged), 3→4 (+ changes to -) once, 4→5 (- changes to +) once: a total of 2 times; Workstation 3: 1→2 (- unchanged), 2→3 (- changes to +) once, 3→4 (+ changes to -) once, 4→5 (- unchanged): a total of 2 times; Workstation 4: 1→2 (+ unchanged), 2→3 (+ unchanged), 3→4 (+ unchanged), 4→5 (+ changes to -) 1 time: 1 time in total.

[0108] The average number of changes across the four workstations = (2+2+2+1) / 4 = 7 / 4 = 1.75 > 1.5, therefore the basic proportional coefficient is adaptively adjusted. .

[0109] As demonstrated by the above examples, by taking the remaining time of each workstation as the control objective, closed-loop temperature control can be formed through adaptive adjustment, enabling the four vibration dampers to synchronously and slowly approach the target temperature. In this embodiment, the basic proportional coefficient is adaptively adjusted once every five cycles. This adjustment frequency not only improves the closed-loop feedback effect but also avoids system oscillation caused by excessively frequent adjustments.

[0110] It should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A closed-loop temperature control method for durability testing of a vibration damper assembly, characterized in that, Follow these steps in sequence: S1: Real-time collection of the internal temperature of the vibration dampers at each workstation; S2: Calculate the heating rate of the vibration damper at each workstation based on its internal temperature. S3: Based on the internal temperature of the vibration damper at each workstation and the preset target temperature, calculate the remaining time and the remaining time deviation for each workstation to reach the target temperature. S4: Based on the changes in water valve opening degree and temperature rise rate, the process gain of each station is obtained in real time; S5: Taking the goal of making the remaining time of each station as consistent as possible, calculate the water valve opening correction amount corresponding to each station based on the remaining time deviation and process gain. S6: The reference opening degree is superimposed with the water valve opening correction amount of each station to synthesize and output the final opening degree of each water valve, so as to independently adjust the cooling water flow of each station and make the vibration damper of each station synchronously and slowly approach the preset target temperature. S7: Based on the difference in water valve opening and whether there is any abnormality in process gain, perform water leakage and failure alarms.

2. The closed-loop temperature control method for durability testing of a vibration damper assembly according to claim 1, characterized in that, In S2, the formula for calculating the heating rate of the vibration damper at each station is: ,when When the value is less than the preset lower limit of 0.02, take... =0.02; Where k is the control cycle number and i is the workstation number. This refers to the real-time temperature of the vibration dampers at each workstation. To control the cycle.

3. The closed-loop control method for temperature during durability testing of a vibration damper assembly according to claim 2, characterized in that, In S3, the formula for calculating the remaining time for each workstation to reach the target temperature is: ,in, The preset target temperature; Calculate the average remaining time for each workstation based on the estimated remaining time to reach the target temperature: ; Calculate the remaining time deviation for each workstation to reach the target temperature: .

4. A closed-loop control method for temperature during durability testing of a vibration damper assembly according to any one of claims 1-3, characterized in that, In S4, the instantaneous gain of each station in the previous cycle is calculated first: ,in, This refers to the water valve opening degree of the previous cycle. This refers to the water valve opening degree for the first two cycles; The current process gain is updated using a smoothing filter: +0.5 ; Initial water valve opening Both are 50%, the initial value of the gain. It is 0.05; if Then the gain Keep the value from the previous period.

5. The closed-loop control method for temperature during durability testing of a vibration damper assembly according to claim 4, characterized in that, In S5, the formula for calculating the water valve opening correction amount for each workstation is: ,in, The basic proportionality coefficient is initially set at 0.01 and is adaptively adjusted during the experiment. right Limiting the amplitude: , The correction amount is limited to the range Inside, a positive value indicates that the water valve is opened wide, and a negative value indicates that the water valve is closed narrowly. This is the preset maximum adjustment range, which is 10%.

6. The closed-loop control method for temperature during durability testing of a vibration damper assembly according to claim 5, characterized in that, The basic proportional coefficient Adaptive adjustment method: Calculate the oscillation index: Calculate the remaining time deviation for each workstation during these five cycles. The number of sign changes is taken as the average of the four workstations. , Calculate the average absolute deviation over the most recent five periods: ， Adjustment rules: like >1.5, then ; like <1.5, and >5, and currently Compared to the previous five-cycle decline of less than 10%, ; otherwise, Remain unchanged; The initial value is 0.01, and the amplitude is limited to (0.001, 1).

7. The closed-loop control method for temperature during durability testing of a vibration damper assembly according to claim 6, characterized in that, In S6, the baseline opening is calculated as follows: ,in, Limit to .

8. The closed-loop temperature control method for durability testing of a vibration damper assembly according to claim 7, characterized in that, In S6, calculate the final opening degree of each water valve: ; Will Limit to The output is then sent to the corresponding water valve actuator.

9. A closed-loop control method for temperature during durability testing of a vibration damper assembly according to any one of claims 1-3 and 5-8, characterized in that, In S7, if the difference in the opening degree of the water valve at each station exceeds the limit, and / or the process gain at the same station remains too low, it is determined that the cooling has failed / leaked, and an alarm is triggered.

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