Diagnostic method for hydraulic suspension

Abstract

A diagnosis method of a hydraulic suspension comprises the steps of detection condition diagnosis, height sensor data comparison, height sensor fault cross diagnosis, pressure sensor fault cross diagnosis and result feedback. Under the condition that the theoretical rising height values of the four suspensions are controlled to be the same, height sensor values and pressure sensor values of the four suspensions are compared in a grouped and crossed mode, fault reasons are checked step by step, and preliminary diagnosis can be conducted on the reasonability of the height sensors and the pressure sensors and system leakage without dismounting the sensors or the suspensions in the method. The comfort and the safety of the vehicle can be guaranteed for a driver, and the maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a diagnosis method of a hydraulic suspension. BACKGROUND

[0002] A pressure sensor is installed in the active hydraulic suspension of the four wheels of a vehicle, and the accuracy of the pressure sensor is directly related to the suspension control effect and the comfort and safety of the vehicle. The pressure sensor may cause zero drift due to changes in the characteristics of the sensitive element, fluctuations in the circuit parameters, and external environmental interference, resulting in errors in the output deviation. Sensor zero drift refers to the unintended deviation of the output signal over time or environmental conditions when the input signal is zero. This phenomenon is usually caused by factors such as temperature changes, material aging, power fluctuations, or mechanical stress, which can cause systematic errors in the measurement results.

[0003] The existing diagnosis method of the hydraulic suspension is to periodically disassemble the pressure sensor by the manufacturer or after-sales, and detect the zero drift by a special device. Although this method can accurately detect the problem, it has obvious shortcomings: first, it cannot predict in advance whether the pressure sensor has appeared zero drift, and second, it must disassemble the height sensor and the pressure sensor to complete the detection, therefore, there is an urgent need for a diagnosis method without disassembling the height sensor and the pressure sensor. SUMMARY

[0004] In view of the above-mentioned shortcomings of the existing diagnosis method of the hydraulic suspension, such as the need to detect after disassembling the pressure sensor and the inability to predict in advance whether zero drift has occurred, the present application provides a reasonable diagnosis method of the hydraulic suspension, which can preliminarily diagnose the rationality of the height sensor and the pressure sensor and the system leakage without disassembling the sensor or the suspension.

[0005] The technical solutions adopted by the present application and the beneficial effects achieved are as follows: A diagnosis method of a hydraulic suspension, comprising the following steps: S1, detection condition diagnosis: the vehicle periodically reminds the driver to trigger the diagnosis function through the interaction system, and checks whether the vehicle meets the detection condition through the controller before triggering the diagnosis, and if it meets, enters S2; S2, height sensor data comparison: the theoretical rising height values of the four suspensions are the same, the height sensor values of the four suspensions are obtained, the actual rising height values are obtained, and it is judged whether the deviation between the actual rising height values and the theoretical rising height values is within the set range, if not, enters S3; if yes, enters S4; S3, cross diagnosis of height sensor fault: group cross compares the deviation between the actual lifting height values of the four suspensions, diagnoses whether there is a height sensor fault, enters S4 if the deviation exceeds the range, and compares the pressure sensor values of the four suspensions one by one if there is no deviation exceeding the range, judges whether the deviation is within the set range, obtains a diagnosis result, and informs the driver through the interaction system; S4, cross diagnosis of pressure sensor fault and result feedback: group cross compares the deviation between the pressure sensor values of the four suspensions, diagnoses whether there is a pressure sensor fault, judges whether the deviation exceeds the set threshold, obtains a diagnosis result, and informs the driver through the interaction system.

[0006] As a further improvement of the above technical solution: S3 further includes: S31, compares the actual lifting height value of a single suspension with the other three, judges whether there is a large deviation, enters S32 if not, and enters S4 if yes.

[0007] S3 further includes: S32, compares the actual lifting height values of two suspensions with the other two, judges whether there is a large deviation, enters S33 if not, and enters S4 if yes.

[0008] S3 further includes: S33, compares the actual lifting height values of the four suspensions one by one, compares the pressure sensor values of the four suspensions one by one if the deviation exceeds the set range, judges whether the deviation of the pressure sensor values is within the set range, informs the driver that there may be a leak through the interaction system if not, and ends the diagnosis; if yes, compares the actual lifting height values of the four suspension height sensors with the theoretical lifting height values, informs the driver which height sensor has a reasonable fault through the interaction system if it exceeds the set range, and ends the diagnosis.

[0009] S4 further includes: S41, compares the pressure sensor values of the four suspensions one by one, judges whether the deviation is within the set range, informs the driver that the system has no fault through the interaction system if yes, and ends the diagnosis; if not, enters S42.

[0010] S4 further includes: S42, compares the pressure sensor value of a single suspension with the other three, judges whether the deviation exceeds the set range, informs the driver that the pressure sensor with the deviation exceeding the set range has a reasonable fault through the interaction system if yes, and enters S43 if not.

[0011] S4 further includes: S43, compare the pressure sensor values of two of the suspensions with the other two, determine whether the deviation exceeds the set threshold, if yes, inform the driver through the interaction system that there are multiple pressure sensors with rationality faults, and the diagnosis ends; if not, inform the driver that there are multiple pressure sensors with rationality faults, and the diagnosis ends.

[0012] S4 further comprises: S44, compare the pressure sensor values of the single suspension with larger height deviation after comparison with the other three, determine whether it is within the set range, if yes, inform the driver through the interaction system that the height sensor of the suspension with larger height deviation has a rationality fault, and the diagnosis ends; if not, inform the driver through the interaction system that the suspension with larger height deviation has a leakage fault, and the diagnosis ends.

[0013] S4 further comprises: S45, compare the pressure sensor values of the two suspensions with lower actual height value with the other two, determine whether the deviation is within the set range, if not, inform the driver through the interaction system that the two suspensions with lower actual height value have a leakage fault, and the diagnosis ends; if yes, enter S46.

[0014] S4 further comprises: S46, if the height sensor values of two of the suspensions are compared with the theoretical height value, determine whether the deviation between the height sensor values of the other two suspensions and the theoretical height value is within the set range, if yes, inform the driver through the interaction system that the height sensors of the two suspensions with larger deviation from the theoretical height value have a rationality fault, and the diagnosis ends; if not, inform the driver that the height sensors of the four suspensions all have a rationality fault, and the diagnosis ends.

[0015] The present application realizes fault troubleshooting through an interaction system, the controller sends the same control parameters, and in the case that the theoretical height values of the four suspensions are the same, the four suspensions are grouped and the height sensor values and pressure sensor values are compared in cross, the fault causes are gradually investigated, and in this method, the height sensors and pressure sensors can be preliminarily diagnosed for rationality and system leakage without disassembling the sensors or suspensions, which is convenient for the driver to ensure the comfort and safety of the vehicle and reduce the maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the system of the present application. DETAILED DESCRIPTION

[0017] The specific embodiment of the present application will be described below in conjunction with the drawings.

[0018] AsFigure 1 As shown, the present application provides a hydraulic suspension diagnosis method, the diagnosis system of which comprises a controller and four suspensions (A, B, C and D respectively) connected thereto, each of which is provided with a valve, a motor, a pressure sensor and a height sensor, and the system feeds back the diagnosis information result to the driver through an interactive system. In the embodiment, the interactive system comprises a mobile phone APP or an in-vehicle man-machine interactive system.

[0019] The steps of the specific hydraulic suspension diagnosis method are as follows: S1, condition detection diagnosis: the vehicle periodically reminds the driver to trigger the diagnosis function through the interactive system, and before triggering, the vehicle needs to be parked on a flat hard road, and whether the detection condition is met is checked through the controller, specifically including that the vehicle speed is 0, the slope is less than a set threshold, the accelerator pedal is zero, the brake system is normal, there is no electrical fault in the system, the gear is P, the high-pressure system is normal (for electric vehicles) or the engine is working normally (for fuel vehicles), if not, the driver is informed through the interactive system, and after the driver handles as required, the diagnosis can be reactivated, if yes, S2 is entered; S2, height sensor data comparison: S21, the vehicle starts detection, if the function is activated through the interactive system, the detection progress is synchronized to the driver's mobile phone. The controller sends the same control parameters (the same motor speed and valve control) to the four shock absorbers, and calculates the theoretical flow value of the hydraulic oil according to the pump speed and efficiency, and calculates the theoretical lifting height value H of the suspension according to the diameter of the shock absorber (H = motor speed * pump displacement * pump volumetric efficiency * time / cross-sectional area of shock absorber, the theoretical lifting height values H of the four suspensions are the same, that is, the theoretical lifting height of the pump rod of the four shock absorbers should be the same); S22, the height sensor values of the four suspensions are obtained, which are converted into the actual lifting height values H of the corresponding suspensions according to the lever ratio A , H B , H C , H D of the four suspensions, and whether the deviation AH between the actual lifting height values and the theoretical lifting height value H of the four suspensions is within the set range (i.e. AH A = |H A -H|, AH B = |H B -H|, AH C = |H C -H|, AH D = |H D -H|) is judged, if not, it is judged that there may be a height sensor fault or a leakage fault, and S3 of height sensor fault cross diagnosis is entered, if yes, S4 of pressure sensor fault cross diagnosis and result feedback is entered; S3, height sensor fault cross diagnosis: S31. Compare the actual lift height of a single suspension with the other three to determine if there is a significant deviation (e.g., H). A With H B H C H D (Compare), if not, proceed to the next step; if yes, proceed to S44; S32. Compare the actual lift height values ​​of two of the suspensions with the other two to determine if there is a significant deviation (e.g., H). A ≈H B H C ≈H D However, |H A -H C |、|H B -H D If the value exceeds the set range, proceed to the next step; if it does, proceed to S45. S33. Compare the actual lift height values ​​of each of the four suspensions. If the deviation exceeds the set range, compare the pressure sensor values ​​of each of the four suspensions to determine if the deviation of the pressure sensor values ​​is within the set range. If not, inform the driver through the interactive system that there may be a leak and ask them to go to a service station to check the four suspensions for leaks. The system will degrade and the diagnosis will end. If yes, compare the actual lift height values ​​of the four suspension height sensors with the theoretical lift height values. If they exceed the set range, inform the driver through the interactive system which height sensor has a reasonable fault. If they do not exceed the set range, it is also recommended that the driver check the four height sensors again. The system will degrade and the diagnosis will end. S4. Cross-diagnosis of pressure sensor faults and feedback of results: S41. Compare the values ​​of the four suspension pressure sensors one by one to determine if the deviation is within the set range. If yes, inform the driver through the interactive system that there is no system fault and the diagnosis ends; otherwise, proceed to the next step. S42. Compare the pressure sensor values ​​of a single suspension with the other three to determine if the deviation exceeds the set range. If so, inform the driver through the interactive system that the pressure sensor exceeding the set range has a reasonable fault and ask the driver to repair it in time; otherwise, proceed to the next step. S43, compare the pressure sensor values of two of the four suspensions with the other two, determine whether the deviation is too large to exceed the set threshold (e.g. suspension A and suspension B are almost equal, suspension C and suspension D are almost equal, but the deviation of suspension A, B and suspension C, D is too large), if so, inform the driver through the interactive system that multiple pressure sensors have reasonable faults, the system will run in degraded mode, please repair in time, and the diagnosis is completed; if not, the deviation of each of the four suspension pressure sensor values is compared one by one, and the deviation exceeds the set threshold, then inform the driver through the interactive system that multiple pressure sensors have reasonable faults, the system will run in degraded mode, please repair in time, and the diagnosis is completed; S44, compare the pressure sensor values of the single suspension with the other three suspensions with the largest deviation in the comparison, determine whether it is within the set range, if so, inform the driver through the interactive system that the height sensor of the suspension with the largest deviation in the comparison has a reasonable fault, please repair in time, and the diagnosis is completed; if not, preliminarily inform the driver through the interactive system that the suspension with the largest deviation in the comparison has a leakage fault, the system will run in degraded mode, please repair at the maintenance station in time, and the diagnosis is completed; S45, compare the pressure sensor values of the two suspensions with the lower actual lifting height value with the other two, determine whether the deviation is within the set range (e.g. suspension A and suspension B are almost equal, suspension C and suspension D are almost equal, but the deviation of suspension A, B and suspension C, D is too large), if not, inform the driver through the interactive system that the two suspensions with the lower actual lifting height value have a leakage fault, and suggest to check the leakage of the four suspensions, the system will run in degraded mode, and the diagnosis is completed; if so, proceed to the next step; S46, if the height sensor values of two of the four suspensions deviate greatly from the theoretical lifting height value H, determine whether the deviation between the height sensor values of the other two suspensions and the theoretical lifting height value is within the set range, if so, inform the driver through the interactive system that the height sensors of the two suspensions deviating greatly from the theoretical lifting height value H have reasonable faults, the system will run in degraded mode, and the diagnosis is completed; if not, i.e. the deviation between the height sensor values of the other two suspensions and the theoretical lifting height value is also large, then inform the driver through the interactive system that the height sensors of the four suspensions all have reasonable faults, the system will run in degraded mode, and the diagnosis is completed.

[0020] The above description is an explanation of the application, not a limitation of the application, and the application can be modified in any form without departing from the spirit of the application.

Claims

1. A diagnostic method for a hydraulic suspension, characterized in that: Includes the following steps: S1, Detection Condition Diagnosis: The vehicle periodically reminds the driver to trigger the diagnostic function through the interactive system. Before triggering the diagnosis, the controller checks whether the vehicle meets the detection conditions. If it does, it enters S2. S2. Height sensor data comparison: Control the theoretical lift height values ​​of the four suspensions to be the same, obtain the height sensor values ​​of the four suspensions, obtain the actual lift height value, and determine whether the deviation between the actual lift height value and the theoretical lift height value is within the set range. If not, proceed to S3; if yes, proceed to S4. S3, Cross-diagnosis of height sensor faults: The deviation between the actual rise height values ​​of the four suspensions is cross-compared in groups to diagnose whether there is a height sensor fault. If the deviation exceeds the range, proceed to S4. If it does not exceed the range, the pressure sensor values ​​of the four suspensions are compared one by one to determine whether the deviation is within the set range. The diagnosis result is obtained and informed to the driver through the interactive system. S4. Pressure sensor fault cross-diagnosis and result feedback: The deviation between the pressure sensor values ​​of the four suspensions is cross-compared in groups to diagnose whether there is a pressure sensor fault, determine whether the deviation exceeds the set threshold, obtain the diagnosis result and inform the driver through the interactive system.

2. The diagnostic method for hydraulic suspension according to claim 1, characterized in that: S3 also includes: S31. Compare the actual lift height of a single suspension with the other three to determine if there is a significant deviation. If not, proceed to S32; if so, proceed to S4.

3. The diagnostic method for hydraulic suspension according to claim 2, characterized in that: S3 also includes: S32. Compare the actual rise height values ​​of two suspensions with the other two to determine if there is a large deviation. If not, proceed to S33; if so, proceed to S4.

4. The diagnostic method for hydraulic suspension according to claim 3, characterized in that: S3 also includes: S33. Compare the actual lift height values ​​of each of the four suspensions one by one. If the deviation exceeds the set range, then compare the pressure sensor values ​​of each of the four suspensions one by one to determine whether the deviation of the pressure sensor values ​​is within the set range. If not, inform the driver through the interactive system that there may be a leak, and the diagnosis ends. If so, compare the actual lift height values ​​of the four suspension height sensors with the theoretical lift height values. If they exceed the set range, inform the driver through the interactive system which height sensor has a reasonable fault, and the diagnosis ends.

5. The diagnostic method for hydraulic suspension according to claim 1, characterized in that: S4 also includes: S41. Compare the values ​​of the four suspension pressure sensors one by one to determine whether the deviation is within the set range. If so, inform the driver through the interactive system that there is no system fault and the diagnosis ends; otherwise, proceed to S42.

6. The diagnostic method for hydraulic suspension according to claim 5, characterized in that: S4 also includes: S42. Compare the pressure sensor value of a single suspension with the other three to determine whether the deviation exceeds the set range. If so, inform the driver through the interactive system that the pressure sensor exceeding the set range has a reasonable malfunction; otherwise, proceed to S43.

7. The diagnostic method for hydraulic suspension according to claim 6, characterized in that: S4 also includes: S43. Compare the values ​​of the pressure sensors of two of the suspensions with the values ​​of the other two to determine whether the deviation exceeds a set threshold. If so, inform the driver through the interactive system that multiple pressure sensors have reasonable malfunctions, and the diagnosis ends. If not, inform the driver that multiple pressure sensors have reasonable malfunctions, and the diagnosis ends.

8. The diagnostic method for hydraulic suspension according to claim 7, characterized in that: S4 also includes: S44. Compare the pressure sensor values ​​of the single suspension with the largest deviation in lift height with the other three to determine if they are within the set range. If so, inform the driver through the interactive system that the height sensor of the suspension with the largest deviation in lift height has a reasonable fault, and the diagnosis ends. If not, inform the driver through the interactive system that the suspension with the largest deviation in lift height has a leakage fault, and the diagnosis ends.

9. The diagnostic method for hydraulic suspension according to claim 8, characterized in that: S4 also includes: S45. Compare the pressure sensor values ​​of the two suspensions with the lower actual lift height with the other two to determine if the deviation is within the set range. If not, inform the driver through the interactive system that the two suspensions with the lower actual lift height have a leakage fault, and the diagnosis ends; if yes, proceed to S46.

10. The diagnostic method for hydraulic suspension according to claim 9, characterized in that: S4 also includes: S46. If the height sensor values ​​of two suspensions deviate significantly from the theoretical lift value, determine whether the deviations between the height sensor values ​​of the other two suspensions and the theoretical lift value are within a set range. If yes, inform the driver through the interactive system that the height sensors of the two suspensions with the larger deviations from the theoretical lift value have reasonable faults, and the diagnosis ends. If no, inform the driver that all four suspension height sensors have reasonable faults, and the diagnosis ends.

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