A method and apparatus for monitoring the failure of a powertrain mounting system for a vehicle

Abstract

The present application relates to the technical field of vehicle power assembly suspension system, in particular to a vehicle power assembly suspension system fault monitoring method and device, the monitoring method comprises, STEP1, static monitoring is carried out when vehicle power is on, STEP2, dynamic monitoring is carried out after engine ignition;The monitoring device comprises suspension system, displacement sensor, acceleration sensor, processor, diagnostic result display device, CAN bus, the present application detects suspension state in real time through static monitoring and dynamic monitoring, determines the operation condition by comparison with pre-stored objective data, eliminates accidental factors, and more accurately, objectively reflects the failure condition of suspension.

Description

Technical Field

[0001] This invention relates to the field of automotive powertrain mounting system technology, specifically a method and device for fault monitoring of automotive powertrain mounting systems. Background Technology

[0002] Automotive powertrain mounting systems support the powertrain and dampen and suppress vibration transmission. They include active mounts, passive mounts, and damping structures such as rubber located between the active and passive mounts. During vehicle development, especially during road testing, it is necessary to regularly check the mounting status to promptly detect any anomalies. Since mountings are usually hidden deep within the engine compartment, it is difficult to detect abnormalities through observation alone. Therefore, employing a detection device to automatically and in real-time monitor the mounting status, enabling timely and accurate identification of when and where anomalies have occurred, is of great importance.

[0003] In addition, after prolonged use, the powertrain mounting system will experience wear and aging, leading to functional failures or even structural malfunctions. If these failures are not detected in time, they could potentially cause safety accidents during driving, resulting in life-threatening situations and economic losses. From this perspective, real-time monitoring devices for the powertrain mounting system also have significant application value in the vehicle.

[0004] Patent application CN202010520977.1 discloses a method, device, equipment, and storage medium for detecting the vibration isolation performance of engine mounts. It uses the vibration isolation rate calculated from the collected vibration accelerations of the active and passive ends as the target for fault diagnosis. However, this patent has the following shortcomings: 1) The vibration isolation performance (isolation rate) of the mount system is greatly affected by its dynamic stiffness characteristics, which are influenced by factors such as temperature, preload, amplitude, and vibration frequency. If the influence of these factors cannot be ruled out, occasional abnormalities in the isolation rate cannot objectively reflect the true failure status of the component. 2) The vibration isolation rate of the system is the combined effect of multiple mounts in the entire system. The vibration isolation rate of a single mount is also affected by other mounts within the system. An abnormality in the isolation rate of a single mount cannot exclude or objectively reflect the factors of interaction and mutual influence among the mounts. 3) The excitation force of the mount system originates from engine vibration excitation and road surface vibration excitation. An abnormality in the mount's vibration isolation rate cannot exclude the influence of complex road surface excitation factors.

[0005] The patent application with application number CN202122559601.4 discloses a powertrain suspension pad with integrated failure warning function. It judges whether the suspension system has failed by whether the contact points are in contact. However, it cannot objectively reflect the actual working status of the suspension system under complex and changing working conditions and cannot rule out accidental factors. Summary of the Invention

[0006] The main objective of this invention is to provide a method and apparatus for fault monitoring of automotive powertrain mounting systems, so as to solve the shortcomings of inaccurate fault monitoring of automotive powertrain mounting systems in the prior art.

[0007] To achieve the above objectives, the present invention provides a method for fault monitoring of a vehicle powertrain mounting system, characterized in that it includes: STEP 1: Perform static monitoring while the vehicle is powered on. The static monitoring steps are as follows: Acquire the measured position signal of the active end of the suspension system in the Z direction; Calculate the relative displacement ΔS of the active end in the Z direction relative to its initial position at the factory. The determination is made by comparing ΔS with the Class I threshold LS1 and the Class II threshold LS2. If LS2 is greater than LS1, and ΔS exceeds the Class I threshold LS1 but does not exceed the Class II threshold LS2, the suspension system is determined to be functionally faulty; if ΔS exceeds the Class II threshold LS2, the suspension system is determined to be structurally faulty; if ΔS does not exceed the Class I threshold LS1, the suspension system is determined to be normal. Once the judgment result is obtained, one static monitoring cycle is completed; STEP 2. After engine ignition, perform dynamic monitoring. The dynamic monitoring steps are as follows: A single acquisition collects vibration acceleration signals from both the active and passive ends; In one calculation, the vibration acceleration signal is converted into a time-domain digital acceleration signal that varies with time. After performing a Fourier transform on the time-domain digital signal, the acceleration frequency-domain signal that varies with the vibration frequency is obtained. In one judgment, the acceleration frequency domain signal is compared with the set vibration acceleration spectrum of the active and passive ends that varies with the vibration frequency. The acceleration value on the vibration acceleration spectrum is the upper limit of the vibration acceleration. If the acceleration frequency domain signal does not exceed the upper limit of the vibration acceleration, the suspension system is judged to be normal. If the acceleration frequency domain signal exceeds the upper limit of vibration acceleration during the second acquisition, the vibration acceleration signals of the active and passive ends will be continuously acquired for 3 cycles at a frequency of 10 seconds followed by a 30-second interval. The second calculation uses a hybrid time-frequency domain integration method to calculate the relative frequency domain amplitude of the active and passive ends of the vibration acceleration. The second determination involves comparing the acceleration frequency domain signal with preset vibration acceleration spectra of the active and passive ends that vary with the vibration frequency. The acceleration value on the vibration acceleration spectrum is the upper limit of the vibration acceleration. The frequency domain relative amplitude of the active and passive ends is compared with preset relative amplitude spectra of the active and passive ends. The relative amplitude value on the relative amplitude spectrum is the upper limit. Case 1: If the frequency domain vibration acceleration of the three cycles of the second acquisition does not exceed the upper limit of the vibration acceleration and the frequency domain relative amplitude does not exceed the upper limit of the relative amplitude, then the suspension system is determined to be normal. Case 2: If the second acquisition... If the frequency domain vibration acceleration of all three cycles exceeds the upper limit of vibration acceleration and the frequency domain relative amplitude exceeds the upper limit of relative amplitude, the suspension system is deemed to have a functional failure. A second acquisition is then performed using the same method. If the frequency domain vibration acceleration of all three cycles in the second acquisition exceeds the upper limit of vibration acceleration and the frequency domain relative amplitude exceeds the upper limit of relative amplitude, the suspension system is deemed to have a structural failure. In case three, if the results of the three cycles of the second acquisition are other than those in cases one and two, the second acquisition, second calculation, and second determination are repeated until a determination result is obtained. Once the judgment result is obtained, one dynamic monitoring cycle ends.

[0008] Furthermore, dynamic monitoring begins with the first monitoring after engine ignition, and then every 30 minutes thereafter.

[0009] Furthermore, the acquisition in STEP1 is achieved using a displacement sensor, while the primary and secondary acquisitions in STEP2 are achieved using an accelerometer.

[0010] Furthermore, the calculations in STEP1 and the primary and secondary calculations in STEP2 are implemented using the processor's computing units.

[0011] Furthermore, the decision-making process in STEP1 and the first and second decisions in STEP2 are implemented using the processor's decision-making unit.

[0012] Furthermore, the Level I threshold LS1 and Level II threshold LS2 in STEP1, and the vibration acceleration spectrum and relative amplitude spectrum in STEP2 are all stored in the processor's storage unit.

[0013] Furthermore, if the judgment result is abnormal, the information collected in STEP1, as well as the information collected in the first and second acquisitions in STEP2, are stored in the processor's storage unit.

[0014] Furthermore, the results of the determination in STEP1 and the first and second determinations in STEP2 are sent to the diagnostic result display device.

[0015] The present invention also provides an apparatus for implementing the above-described method for fault monitoring of automotive powertrain mounting systems, comprising: The suspension system includes an active end, a passive end, and a rubber body located between the active end and the passive end; Displacement sensor used to measure displacement at the active end; Accelerometer used to measure acceleration at both the active and passive ends; The processor includes a computing unit, a decision unit, and a storage unit, which are used to convert and calculate the acquired data, make decisions based on set logic, and store the data, respectively. A diagnostic result display device is used to receive and display the judgment results of the judgment unit; The CAN bus is used for connection and communication between displacement sensors, accelerometers, processors, and diagnostic result display devices.

[0016] The fault monitoring method for vehicle powertrain mounting system of the present invention detects the mounting status in real time through static and dynamic monitoring, and determines the operating status by comparing it with pre-stored objective data, eliminating accidental factors and reflecting the failure status of the mounting more accurately and objectively.

[0017] The device for implementing the fault monitoring method of the vehicle powertrain mounting system of the present invention has high integration, strong versatility and portability, and can meet the implementation of the fault monitoring method of the vehicle powertrain mounting system, and can help vehicle drivers obtain abnormal conditions of the vehicle powertrain mounting system in real time. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 A schematic diagram of the device for implementing a fault monitoring method for automotive powertrain mounting systems; Figure 2 This is a flowchart of the static monitoring process; Figure 3 A flowchart for dynamic monitoring; In the diagram: 1. Suspension system; 11. Active end; 12. Passive end; 2. Displacement sensor; 3. Accelerometer; 4. CAN bus; 5. Processor; 6. Diagnostic result display device. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Reference Figure 1 The device for implementing a fault monitoring method for a vehicle powertrain mounting system includes a mounting system 1, a displacement sensor 2, two acceleration sensors 3, a CAN bus 4, a processor 5, and a diagnostic result display device 6.

[0022] The suspension system 1 includes an active end 11, a passive end 12, and a rubber body located between the active end 11 and the passive end 12; The displacement sensor 2 is a miniature eddy current displacement sensor, including a probe and a preamplifier. The probe is set on the vehicle body below the active end 11 and is used to measure the displacement of the active end 11. Both accelerometers 3 are general-purpose triaxial vibration sensors, each including a probe and a preamplifier. One probe is connected to the active end 11, and the other probe is connected to the passive end 12. Processor 5 includes a computing unit, a decision unit, and a storage unit, which are used to convert and calculate the acquired data, make decisions based on set logic, and store the data, respectively. The diagnostic result display device 6 is a vehicle instrument panel, physical fault warning light, buzzer, or voice prompt installed in the driver's cab, used to receive and display the judgment results of the judgment unit; The CAN bus 4 is connected to the displacement sensor 2, the acceleration sensor 3, the processor 5, and the diagnostic result display device 6, and is used for connection and communication between the displacement sensor 2, the acceleration sensor 3, the processor 5, and the diagnostic result display device 6.

[0023] Reference Figure 2 and Figure 3 The present invention also provides a method for fault monitoring of a vehicle powertrain mounting system, comprising: STEP 1: Perform static monitoring while the vehicle is powered on. The static monitoring steps are as follows: The displacement sensor 2 collects the measured position signal of the active end 11 of the suspension system 1 in the Z direction; The processor 5's computing unit calculates the relative displacement ΔS of the active terminal 11 in the Z direction relative to its initial position at the factory. The processor 5's determination unit compares ΔS with the Level I threshold LS1 and Level II threshold LS2 stored in the processor 5's storage unit. If LS2 is greater than LS1, and ΔS exceeds the Level I threshold LS1 but does not exceed the Level II threshold LS2, the suspension system is determined to be functionally faulty, prompting the user to check; if ΔS exceeds the Level II threshold LS2, the suspension system is determined to be structurally faulty, prompting fault repair; if ΔS does not exceed the Level I threshold LS1, the suspension system is determined to be normal. The determination results are all sent to the diagnostic result display device 6. When the determination result is abnormal, the collected information is stored in the processor 5's storage unit to assist in the effective tracing of possible after-sales faults and subsequent fault analysis. Once the judgment result is obtained, one static monitoring cycle is completed; STEP 2. After engine ignition, perform the first dynamic monitoring. The dynamic monitoring steps are as follows: In a single data acquisition, the accelerometer 3 collects vibration acceleration signals from the active end 11 and the passive end 12. In one calculation, the computing unit of processor 5 converts the vibration acceleration signal into a digital acceleration time-domain signal that varies with time. After performing a Fourier transform on the digital acceleration time-domain signal, a frequency-domain acceleration signal that varies with vibration frequency is obtained. In one judgment, the judgment unit of processor 5 compares the acceleration frequency domain signal with the vibration acceleration spectrum of the active end and passive end that changes with the vibration frequency set in the storage unit of processor 5. The acceleration value on the vibration acceleration spectrum is the upper limit of the vibration acceleration. If the acceleration frequency domain signal does not exceed the upper limit of the vibration acceleration, the suspension system is judged to be normal. If the acceleration frequency domain signal exceeds the upper limit of vibration acceleration during the second acquisition, then the acceleration sensor 3 will continuously acquire the vibration acceleration signal of the active end 11 and the passive end 12 for 3 cycles at a frequency of 10 seconds followed by 30 seconds. In the secondary calculation, the computing unit of processor 5 calculates the relative amplitude in the frequency domain of the active and passive ends by using the time-frequency domain hybrid integration method of vibration acceleration; In the second determination, the determination unit of processor 5 compares the acceleration frequency domain signal with the vibration acceleration spectra of the active and passive ends, which vary with the vibration frequency and are stored in the processor 5's storage unit. The acceleration value on the vibration acceleration spectrum is the upper limit of the vibration acceleration. The relative amplitude in the frequency domain of the active and passive ends is compared with the relative amplitude spectra of the active and passive ends, which are stored in the processor 5's storage unit. The relative amplitude value on the relative amplitude spectra is the upper limit. In case one, if the frequency domain vibration acceleration of the three collected cycles does not exceed the upper limit of the vibration acceleration and the relative amplitude in the frequency domain does not exceed the upper limit of the relative amplitude, the suspension system is determined to be normal. In case two, if the frequency domain vibration acceleration of the three collected cycles exceeds the upper limit of the vibration acceleration and the relative amplitude in the frequency domain does not exceed the upper limit of the relative amplitude, the suspension system is determined to be normal. If the amplitude exceeds the upper limit of the relative amplitude, the suspension system is deemed to have a functional failure. The user is prompted to check, and a second acquisition is performed using the secondary acquisition method. If the frequency domain vibration acceleration of the three cycles of the second acquisition all exceed the upper limit of the vibration acceleration and the frequency domain relative amplitude all exceed the upper limit of the relative amplitude, the suspension system is deemed to have a structural failure. Case 3: If the results of the three cycles of the secondary acquisition are other than those in Case 1 and Case 2, the secondary acquisition, secondary calculation, and secondary judgment are repeated until a judgment result is obtained. All judgment results are sent to the diagnostic result display device 6. If the judgment result is abnormal, the information from the first and second acquisitions is stored in the storage unit of the processor 5 to assist in the effective tracing of possible after-sales faults and subsequent fault analysis. Once the results are available, one round of dynamic monitoring ends; thereafter, monitoring is conducted every 30 minutes.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for fault monitoring of a vehicle powertrain mounting system, characterized in that, include: STEP 1: Perform static monitoring while the vehicle is powered on. The static monitoring steps are as follows: Acquire the measured position signal of the active end (11) of the suspension system (1) in the Z direction; Calculate the relative displacement ΔS of the active end (11) in the Z direction relative to its initial position at the factory. The determination is made by comparing ΔS with the Class I threshold LS1 and the Class II threshold LS2. If LS2 is greater than LS1, and ΔS exceeds the Class I threshold LS1 but does not exceed the Class II threshold LS2, the suspension system is determined to be functionally faulty; if ΔS exceeds the Class II threshold LS2, the suspension system is determined to be structurally faulty; if ΔS does not exceed the Class I threshold LS1, the suspension system is determined to be normal. Once the judgment result is obtained, one static monitoring cycle is completed; STEP 2. After engine ignition, perform dynamic monitoring. The dynamic monitoring steps are as follows: In one acquisition, the vibration acceleration signals of the active end (11) and the passive end (12) are acquired; In one calculation, the vibration acceleration signal is converted into a time-domain digital acceleration signal that varies with time. After performing a Fourier transform on the time-domain digital signal, the acceleration frequency-domain signal that varies with the vibration frequency is obtained. In one judgment, the acceleration frequency domain signal is compared with the set vibration acceleration spectrum of the active end (11) and passive end (12) that varies with the vibration frequency. The acceleration value on the vibration acceleration spectrum is the upper limit of the vibration acceleration. If the acceleration frequency domain signal does not exceed the upper limit of the vibration acceleration, the suspension system is judged to be normal. If the acceleration frequency domain signal exceeds the upper limit of vibration acceleration during the second acquisition, the vibration acceleration signal of the active end (11) and the passive end (12) will be continuously acquired for 3 cycles at a frequency of 10 seconds followed by 30 seconds. Secondary calculation: The relative amplitude in the frequency domain of the active end (11) and the passive end (12) is calculated by the time-frequency domain hybrid integration method of vibration acceleration; In the second determination, the acceleration frequency domain signal is compared with the set vibration acceleration spectrum of the active end (11) and passive end (12) that varies with the vibration frequency. The acceleration value on the vibration acceleration spectrum is the upper limit of the vibration acceleration. The frequency domain relative amplitude of the active end (11) and passive end (12) is compared with the set relative amplitude spectrum of the active end (11) and passive end (12). The relative amplitude value on the relative amplitude spectrum is the upper limit. In case one, if the frequency domain vibration acceleration of the three cycles of the second acquisition does not exceed the upper limit of the vibration acceleration and the frequency domain relative amplitude does not exceed the upper limit of the relative amplitude, then the suspension system is determined to be... Normal; Case 2: If the frequency domain vibration acceleration of all three cycles of the secondary acquisition exceeds the upper limit of vibration acceleration and the frequency domain relative amplitude exceeds the upper limit of relative amplitude, the suspension system is deemed to have a functional failure. The acquisition is then performed again using the same method as in the secondary acquisition. If the frequency domain vibration acceleration of all three cycles of the second acquisition exceeds the upper limit of vibration acceleration and the frequency domain relative amplitude exceeds the upper limit of relative amplitude, the suspension system is deemed to have a structural failure; Case 3: If the results of the three cycles of the secondary acquisition are any other than Case 1 and Case 2, the secondary acquisition, secondary calculation, and secondary judgment are repeated until a judgment result is obtained. Once the judgment result is obtained, one dynamic monitoring cycle ends.

2. The method for fault monitoring of a vehicle powertrain mounting system as described in claim 1, characterized in that, Dynamic monitoring begins for the first time after engine ignition, and is subsequently monitored every 30 minutes thereafter.

3. The method for fault monitoring of a vehicle powertrain mounting system as described in claim 1, characterized in that, The acquisition in STEP1 is achieved using a displacement sensor (2), and the primary and secondary acquisitions in STEP2 are achieved using an acceleration sensor (3).

4. The method for fault monitoring of a vehicle powertrain mounting system as described in claim 1, characterized in that, The calculations in STEP1 and the first and second calculations in STEP2 are implemented using the computing unit of the processor (5).

5. A method for fault monitoring of a vehicle powertrain mounting system as described in claim 1, characterized in that, The determination in STEP1 and the first and second determinations in STEP2 are implemented using the determination unit of the processor (5).

6. A method for fault monitoring of a vehicle powertrain mounting system as described in claim 1, characterized in that, The Level I threshold LS1 and Level II threshold LS2 in STEP1, and the vibration acceleration spectrum and relative amplitude spectrum in STEP2 are all stored in the storage unit of the processor (5).

7. A method for fault monitoring of a vehicle powertrain mounting system as described in claim 1, characterized in that, When the determination result is abnormal, the information collected in STEP1 and the information collected in the first and second collections in STEP2 are stored in the storage unit of the processor (5).

8. A method for fault monitoring of a vehicle powertrain mounting system as described in claim 1, characterized in that, The results of the determination in STEP1 and the first and second determinations in STEP2 are sent to the diagnostic result display device (6).

9. An apparatus for implementing the fault monitoring method for a vehicle powertrain mounting system as described in claim 1, characterized in that, include: The suspension system (1) includes an active end (11), a passive end (12) and a rubber body located between the active end (11) and the passive end (12); Displacement sensor (2) used to measure displacement of the active end; An accelerometer (3) is used to measure the acceleration of the active end (11) and the passive end (12). The processor (5) includes a computing unit, a judgment unit and a storage unit, which are used to convert and calculate the collected data, make judgments according to the set logic and store the data, respectively. The calculations in STEP1 and the first and second calculations in STEP2 are implemented using the computing unit of the processor (5); The determination in STEP1 and the first and second determinations in STEP2 are implemented using the determination unit of the processor (5); The diagnostic result display device (6) is used to receive and display the judgment result of the judgment unit; The CAN bus (4) is used for connection and communication between the displacement sensor (2), the acceleration sensor (3), the processor (5), and the diagnostic result display device (6).

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