Method and device for diagnosing electrical signal faults in air suspension solenoid valves of commercial vehicles

Abstract

This invention provides a method and device for diagnosing electrical signal faults in air suspension solenoid valves of commercial vehicles, belonging to the technical field of vehicle controller hardware and basic software development. The method includes: acquiring the electrical signal of the solenoid valve to be tested collected by the solenoid valve control circuit; continuously matching the electrical signal of the solenoid valve to be tested with preset fault diagnosis conditions to obtain the solenoid valve fault diagnosis result; the fault diagnosis conditions are: power supply short circuit fault diagnosis condition, ground short circuit fault diagnosis condition, and open circuit fault diagnosis condition. The method proposed in this invention solves the technical problems of low accuracy and limited fault type diagnosis in existing fault diagnosis methods.

Description

Technical Field

[0001] This invention relates to the field of vehicle controller hardware and basic software development technology, specifically to a method and device for diagnosing electrical signal faults in a commercial vehicle air suspension solenoid valve. Background Technology

[0002] As one of the most important actuators in the entire air suspension system, the solenoid valve plays a crucial role in adjusting the suspension height and ensuring the smooth operation of the vehicle. Therefore, fault diagnosis of solenoid valves is essential. Currently, fault diagnosis of solenoid valves generally involves adding additional fault diagnosis devices, such as external current sensors to detect whether the current is normal, adding logic operation circuits and integrated chips to detect the solenoid valve status, or using simple diagnostic feedback circuits such as high-side and low-side MOSFETs and comparators. Ultimately, the diagnostic signal or the diagnostic result is transmitted to the MCU for further judgment and response.

[0003] The most direct problem with fault diagnosis using additional fault diagnosis devices is increased cost. Secondly, various sensors provide limited diagnostic signals, and their sensitivity is difficult to guarantee. Even with integrated chips to improve data accuracy, the diagnostic information ultimately fed back to the MCU remains limited. The MCU can only generally determine the presence of a fault, but struggles to pinpoint the specific fault type, or can only diagnose a single fault type. Furthermore, to ensure precise control of air suspension airbag inflation and deflation, the solenoid valve drive enable control employs relatively complex drive methods such as PWM, leading to more variable operating conditions and higher demands on fault diagnosis and de-vibration. Traditional fault diagnosis methods struggle to guarantee accuracy in these areas, easily resulting in false alarms. Therefore, existing fault diagnosis methods suffer from low accuracy and limited fault type diagnosis. Summary of the Invention

[0004] In view of this, it is necessary to provide a method and device for diagnosing electrical signal faults of air suspension solenoid valves in commercial vehicles, so as to solve the technical problems of low accuracy and limited fault types in existing fault diagnosis methods.

[0005] To address the aforementioned technical problems, this invention provides, on the one hand, a method for diagnosing electrical signal faults in a commercial vehicle air suspension solenoid valve, comprising:

[0006] Acquire the electrical signal of the solenoid valve to be tested from the solenoid valve control circuit; the electrical signal of the solenoid valve to be tested is: the feedback voltage and drive duty cycle of the solenoid valve.

[0007] The electrical signal of the solenoid valve to be tested is continuously matched with the preset fault diagnosis conditions to obtain the fault diagnosis result of the solenoid valve; the fault diagnosis conditions are: power supply short circuit fault diagnosis condition, ground short circuit fault diagnosis condition and open circuit fault diagnosis condition.

[0008] In one possible implementation, the step of continuously matching the electrical signal of the solenoid valve to be detected with preset fault diagnosis conditions to obtain the solenoid valve fault diagnosis result includes:

[0009] The solenoid valve drive duty cycle is matched with a preset duty cycle threshold to determine the solenoid valve enable switch opening and closing state; the solenoid valve enable switch opening and closing states are: closed, open, and periodic opening and closing.

[0010] Once the electromagnetic enable switch is in the open / closed state, the feedback voltage of the solenoid valve is continuously matched with the preset power supply short circuit fault diagnosis conditions, ground short circuit fault diagnosis conditions, and open circuit fault diagnosis conditions to obtain the solenoid valve fault diagnosis results.

[0011] In one possible implementation, the step of continuously matching the feedback voltage of the solenoid valve with preset power supply short-circuit fault diagnosis conditions, ground short-circuit fault diagnosis conditions, and open-circuit fault diagnosis conditions, respectively, to obtain the solenoid valve fault diagnosis result, includes:

[0012] When the solenoid valve enable switch is closed, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a short circuit to ground fault and the feedback voltage of the solenoid valve when there is an open circuit fault, respectively, to obtain the fault diagnosis status of the solenoid valve and the first matching time.

[0013] The first matching time is compared with the preset debouncing time. If the first matching time is greater than the debouncing time, the solenoid valve fault diagnosis result is obtained based on the fault diagnosis status.

[0014] In one possible implementation, the step of continuously matching the feedback voltage of the solenoid valve with preset power supply short-circuit fault diagnosis conditions, ground short-circuit fault diagnosis conditions, and open-circuit fault diagnosis conditions, respectively, to obtain the solenoid valve fault diagnosis result, includes:

[0015] When the solenoid valve enable switch is opened, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when the power supply is short-circuited, so as to obtain the fault diagnosis status and the second matching time of the solenoid valve.

[0016] The second matching time is compared with the preset debouncing time. If the second matching time is greater than the debouncing time, the solenoid valve fault diagnosis result is obtained based on the fault diagnosis status.

[0017] In one possible implementation, the step of continuously matching the feedback voltage of the solenoid valve with preset power supply short-circuit fault diagnosis conditions, ground short-circuit fault diagnosis conditions, and open-circuit fault diagnosis conditions, respectively, to obtain the solenoid valve fault diagnosis result, after determining the on / off state of the electromagnetic enable switch, further includes:

[0018] When the solenoid valve enable switch is periodically opened and closed, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a power short circuit fault, the feedback voltage of the solenoid valve when there is a ground short circuit fault, and the feedback voltage of the solenoid valve when there is an open circuit fault, so as to obtain the solenoid valve fault diagnosis result.

[0019] In one possible implementation, the step of continuously matching the feedback voltage of the solenoid valve with preset feedback voltages for power supply short-circuit faults, ground short-circuit faults, and open-circuit faults to obtain a solenoid valve fault diagnosis result includes:

[0020] The feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a power short circuit fault, the feedback voltage of the solenoid valve when there is a ground short circuit fault, and the feedback voltage of the solenoid valve when there is an open circuit fault, respectively, to obtain the fault diagnosis status of the solenoid valve and the third matching time.

[0021] The third matching time is matched with the preset time. If the third matching time is greater than the preset time, the fault diagnosis result of the solenoid valve is obtained based on the fault diagnosis status. The solenoid valve level status is: low level, medium level and high level.

[0022] In one possible implementation, the fault diagnosis result includes:

[0023] Open circuit, short circuit to ground, and short circuit to power supply.

[0024] In one possible implementation, the third matching time is obtained through the following steps:

[0025] The feedback voltage of the solenoid valve is continuously matched with a preset voltage threshold to obtain the solenoid valve's level state and the number of times the level state is matched. Based on the number of times the solenoid valve's level state is matched and the obtained solenoid valve fault diagnosis scheduling cycle, the third matching time is obtained.

[0026] In one possible implementation, the third matching time is obtained by combining the number of matching times based on the solenoid valve's level state and the acquired solenoid valve fault diagnosis scheduling cycle, including:

[0027] The third matching time is obtained by multiplying the number of matching times of the solenoid valve's level state by the obtained solenoid valve fault diagnosis scheduling cycle.

[0028] On the other hand, the present invention also provides a fault diagnosis device for the electrical signal of the air suspension solenoid valve of a commercial vehicle, comprising:

[0029] The solenoid valve control circuit module is used to acquire the electrical signal of the solenoid valve to be tested collected by the solenoid valve control circuit; the electrical signal of the solenoid valve to be tested is: the feedback voltage and the drive duty cycle of the solenoid valve.

[0030] The matching module is used to continuously match the electrical signal of the solenoid valve to be tested with preset fault diagnosis conditions to obtain the fault diagnosis result of the solenoid valve. The fault diagnosis conditions are: power supply short circuit fault diagnosis condition, ground short circuit fault diagnosis condition, and open circuit fault diagnosis condition.

[0031] The beneficial effects of this invention are as follows: The commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method provided by this invention includes: acquiring the solenoid valve electrical signal to be tested collected by the solenoid valve control circuit; the solenoid valve electrical signal to be tested is: the feedback voltage and drive duty cycle of the solenoid valve; continuously matching the solenoid valve electrical signal to be tested with preset fault diagnosis conditions to obtain the solenoid valve fault diagnosis result; the purpose of this is to match the solenoid valve electrical signal to be tested with preset fault diagnosis conditions through fault diagnosis software. The fault diagnosis conditions set by the fault diagnosis software involved in this application mainly involve nine fault state analyses, ultimately realizing fault diagnosis of the solenoid valve under three different operating conditions, with clear and complete diagnostic logic, covering all solenoid valve operating conditions and all possible fault types. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic flowchart of an embodiment of the method for diagnosing electrical signal faults in a commercial vehicle air suspension solenoid valve provided by the present invention;

[0034] Figure 2 A fault diagnosis principle diagram of an embodiment of the fault diagnosis method for the solenoid valve of air suspension in commercial vehicles provided by the present invention;

[0035] Figure 3 A high-side diagnostic circuit diagram of an embodiment of the fault diagnosis method for the solenoid valve of air suspension in commercial vehicles provided by the present invention;

[0036] Figure 4The bottom diagnostic circuit diagram is an embodiment of the fault diagnosis method for the solenoid valve of the air suspension of a commercial vehicle provided by the present invention.

[0037] Figure 5 A valve switch closing feedback voltage state diagram of an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method provided by the present invention;

[0038] Figure 6 A valve switch fully open feedback voltage state diagram, which is an embodiment of the fault diagnosis method for the electromagnetic valve of the air suspension of a commercial vehicle provided by the present invention.

[0039] Figure 7 A valve switch half-open feedback voltage state diagram of an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method provided by the present invention;

[0040] Figure 8 This is a schematic diagram of an embodiment of the electrical signal fault diagnosis device for the air suspension solenoid valve of a commercial vehicle provided by the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] In the description of the embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0043] In this embodiment of the invention, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, apparatus, product or device that includes a series of steps or modules is not necessarily limited to those steps or modules that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to such process, method, product or device.

[0044] The naming or numbering of steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical order indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effect can be achieved.

[0045] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0046] This invention provides a method and device for diagnosing electrical signal faults in the air suspension solenoid valve of a commercial vehicle, which will be described below.

[0047] Figure 1 A schematic flowchart of an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method provided by the present invention. Figure 2 A fault diagnosis principle diagram of an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method provided by the present invention includes:

[0048] S101. Acquire the electrical signal of the solenoid valve to be tested collected by the solenoid valve control circuit; the electrical signal of the solenoid valve to be tested is: the feedback voltage and drive duty cycle of the solenoid valve.

[0049] S102. Continuously match the electrical signal of the solenoid valve to be tested with the preset fault diagnosis conditions to obtain the fault diagnosis result of the solenoid valve; the fault diagnosis conditions are: power supply short circuit fault diagnosis condition, ground short circuit fault diagnosis condition and open circuit fault diagnosis condition.

[0050] It is understandable that in step S101, based on the hardware circuit, the variables used for diagnosis are determined, and the corresponding diagnostic variable values ​​(DIO (Digital in and out) level / ADC (Analog to Digital Converter) acquisition value / PWM (Pulse Width Modulation) signal) are obtained according to their corresponding pin modes.

[0051] In step S102, based on the hardware circuit, the fault diagnosis conditions are determined, and it is judged whether the obtained diagnostic variable values ​​meet the fault diagnosis conditions. When a fault occurs, if the time for which the fault diagnosis conditions are met continuously is greater than a specified time, then the fault is confirmed to have occurred and is reported to the DEM (Digital Elevation Model). When the fault disappears, if the time for which the fault recovery conditions are met continuously is greater than a specified time, then the fault recovery is confirmed and is reported to the DEM.

[0052] It should be further explained that the method for diagnosing electrical signal faults in commercial vehicle air suspension solenoid valves proposed in this application describes the hardware drive and diagnostic circuit of the air suspension solenoid valve and elaborates on the software fault diagnosis strategy. This embodiment has broad coverage and stable performance. It has been applied to the Dongfeng Commercial Vehicle's independent air suspension controller project and has undergone comprehensive verification through bench testing and real vehicle reliability testing. The diagnosis is effective and accurate, improving the safety performance of the solenoid valve and providing strong protection for the safe and stable operation of the entire vehicle.

[0053] Figure 3 A high-side diagnostic circuit diagram of an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method provided by the present invention and Figure 4 The bottom diagnostic circuit diagram of an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method provided by the present invention includes:

[0054] The solenoid valve drive duty cycle is matched with a preset duty cycle threshold to determine the solenoid valve enable switch opening and closing state; the solenoid valve enable switch opening and closing states are: closed, open, and periodic opening and closing.

[0055] With the electromagnetic enable switch in a certain open / closed state, the feedback voltage of the solenoid valve is continuously matched with the preset power supply short circuit fault diagnosis conditions, ground short circuit fault diagnosis conditions, and open circuit fault diagnosis conditions to obtain the solenoid valve fault diagnosis results.

[0056] It is understandable that the air suspension solenoid valve proposed in this application uses high-side power supply and low-side drive, and both high-side and low-side circuits need to be fault-diagnosed to ensure the safe and stable operation of the solenoid valve.

[0057] It can be further understood that, in Figure 3 In the middle section, the power supply of the high-side solenoid valve is controlled by a driver chip, which is connected to the main power supply of the controller. Its enabling and disabling are controlled by the MCU. The diagnostic variable for the high-side solenoid valve power supply is the AD acquisition value of the solenoid valve power supply feedback voltage. After determining the normal operating range of the solenoid valve power supply based on system requirements, the normal range corresponding to the AD acquisition value of the solenoid valve power supply feedback voltage can be calculated by using resistors R1 and R2 for voltage division. The specific diagnostic logic is as follows:

[0058] 1) When the AD acquisition value of the solenoid valve power supply feedback voltage is within the normal range and the duration exceeds the debouncing preset time, it is confirmed as a normal state and reported to DEM.

[0059] 2) When the AD acquisition value of the solenoid valve power supply feedback voltage is less than the short-circuit voltage threshold to ground, and the duration exceeds the debouncing preset time, it is confirmed as a short-circuit fault to ground in the solenoid valve power supply, and the fault is reported to DEM.

[0060] It can be further understood that, in Figure 4 In the middle section, the low-side drive circuit consists of a drive chip enable control circuit, a drive feedback voltage acquisition circuit, and a dedicated open-circuit diagnostic circuit. The MCU (Microcontroller Unit) controls the drive chip (active high) via PWM. The solenoid valve fault diagnosis variables include the AD acquisition value of the solenoid valve drive feedback voltage, as well as the PWM drive period and duty cycle. The drive feedback voltage exhibits different states when the drive pin is enabled and disabled.

[0061] 1) When the enable level is low, the low-side drive switch is off:

[0062] (1) Normal state: The power supply of the high side of the solenoid valve is equivalent to the direct action on point A, and the feedback voltage at point B is the voltage value after the solenoid valve power supply voltage is divided by R3 and R4;

[0063] (2) For the power supply short circuit state: the high-side power supply of the solenoid valve acts directly on point A, and the feedback voltage at point B is the voltage value of the solenoid valve power supply voltage after being divided by R3 and R4;

[0064] (3) Short circuit to ground: Both points A and B are short-circuited to ground, and the feedback voltage is approximately 0;

[0065] (4) Open circuit state: Point A is pulled up to the solenoid valve power supply through the open circuit dedicated diagnostic circuit, and the feedback voltage at point B is the voltage value of the solenoid valve power supply voltage after being divided by R5, R3, and R4.

[0066] In summary, when the enable level is low and the low-side drive switch is off, the phenomena of normal operation and short-circuit fault to power supply are identical and indistinguishable. Therefore, only short-circuit to ground and open-circuit faults can be diagnosed under these conditions.

[0067] 2) When the enable level is high, the low-side drive switch is turned on, and pins 2 and 3 of the drive chip switch are equivalent to being connected to ground:

[0068] (1) Normal state: The voltage at points A and B is equivalent to being pulled down to ground, and the feedback voltage is approximately 0;

[0069] (2) For power supply short circuit: The solenoid valve power supply acts directly on point A. The low-side drive switch is self-protected and shuts off due to the large current. The feedback voltage at point B is the voltage value of the solenoid valve power supply voltage after being divided by R3 and R4.

[0070] (3) Short circuit to ground: Both points A and B are short-circuited to ground, and the feedback voltage is approximately 0;

[0071] (4) Open circuit state: The voltage at points A and B is equivalent to being pulled down to ground, and the feedback voltage is approximately 0.

[0072] In summary, when the enable level is high and the low-side drive switch is open, the phenomena of normal state, short circuit to ground fault state, and open circuit fault state are identical and indistinguishable. Therefore, only power supply short circuit fault diagnosis can be performed in this state. Based on the above analysis of the feedback voltage state under the two conditions of enable switch open and closed, it can be concluded that short circuit to ground and open circuit faults need to be diagnosed when the enable switch is closed, and short circuit faults to the power supply need to be diagnosed when the enable switch is open. Furthermore, since the solenoid valve is driven by PWM, when the drive duty cycle is within the range of 0%~100%, the drive level fluctuates, and the previously described discrimination method cannot effectively debouncing and filtering. Therefore, in this state, fault diagnosis must also be performed in conjunction with the PWM drive cycle and duty cycle.

[0073] Figure 5 A valve switch closing feedback voltage state diagram, as provided in an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method of the present invention, includes:

[0074] When the solenoid valve enable switch is closed, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a short circuit to ground fault and the feedback voltage of the solenoid valve when there is an open circuit fault, respectively, to obtain the fault diagnosis status of the solenoid valve and the first matching time.

[0075] The first matching time is compared with the preset debouncing time. If the first matching time is greater than the debouncing time, the solenoid valve fault diagnosis result is obtained based on the fault diagnosis status.

[0076] It is understandable that when the enable level is low, the low-side drive switch is turned off:

[0077] (1) Normal state: The power supply of the high side of the solenoid valve is equivalent to the direct action on point A, and the feedback voltage at point B is the voltage value after the solenoid valve power supply voltage is divided by R3 and R4;

[0078] (2) For the power supply short circuit state: the high-side power supply of the solenoid valve acts directly on point A, and the feedback voltage at point B is the voltage value of the solenoid valve power supply voltage after being divided by R3 and R4;

[0079] (3) Short circuit to ground: Both points A and B are short-circuited to ground, and the feedback voltage is approximately 0;

[0080] (4) Open circuit state: Point A is pulled up to the solenoid valve power supply through the open circuit dedicated diagnostic circuit, and the feedback voltage at point B is the voltage value of the solenoid valve power supply voltage after being divided by R5, R3, and R4.

[0081] In summary, when the enable level is low and the low-side drive switch is off, the phenomena of normal operation and short-circuit fault to power supply are identical and indistinguishable. Therefore, only short-circuit to ground and open-circuit faults can be diagnosed under these conditions.

[0082] Figure 6 A valve switch fully open feedback voltage state diagram, as provided in an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method of the present invention, includes:

[0083] When the solenoid valve enable switch is opened, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when the power supply is short-circuited, so as to obtain the fault diagnosis status and the second matching time of the solenoid valve.

[0084] The second matching time is compared with the preset debouncing time. If the second matching time is greater than the debouncing time, the solenoid valve fault diagnosis result is obtained based on the fault diagnosis status.

[0085] Understandably, when the enable level is high, the low-side drive switch is turned on, and pins 2 and 3 of the drive chip switch are equivalent to being connected to ground.

[0086] (1) Normal state: The voltage at points A and B is equivalent to being pulled down to ground, and the feedback voltage is approximately 0;

[0087] (2) For power supply short circuit: The solenoid valve power supply acts directly on point A. The low-side drive switch is self-protected and shuts off due to the large current. The feedback voltage at point B is the voltage value of the solenoid valve power supply voltage after being divided by R3 and R4.

[0088] (3) Short circuit to ground: Both points A and B are short-circuited to ground, and the feedback voltage is approximately 0;

[0089] (4) Open circuit state: The voltage at points A and B is equivalent to being pulled down to ground, and the feedback voltage is approximately 0.

[0090] In summary, when the enable level is high and the low-side drive switch is open, the phenomena of normal state, short-circuit to ground fault state, and open-circuit fault state are identical and indistinguishable. Therefore, only power supply short-circuit fault diagnosis can be performed in this state. Based on the above analysis of the feedback voltage state under the two conditions of enable switch being open and closed, it can be concluded that it is necessary to diagnose both short-circuit to ground and open-circuit faults when the enable switch is closed, and to diagnose power supply short-circuit faults when the enable switch is open.

[0091] Figure 7 A valve switch half-open feedback voltage state diagram, as provided in an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method of the present invention, includes:

[0092] When the solenoid valve enable switch is periodically opened and closed, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a power short circuit fault, the feedback voltage of the solenoid valve when there is a ground short circuit fault, and the feedback voltage of the solenoid valve when there is an open circuit fault, so as to obtain the solenoid valve fault diagnosis result.

[0093] Understandably, in addition, since the solenoid valve is driven by PWM, when the drive duty cycle is in the range of 0% to 100%, the drive level is sometimes high and sometimes low. The judgment method mentioned above cannot effectively debouncing and filtering. Therefore, in this state, it is also necessary to combine the PWM drive cycle and duty cycle for fault diagnosis.

[0094] In some embodiments of the present invention, the step of continuously matching the feedback voltage of the solenoid valve with the feedback voltage of the solenoid valve during a preset power short-circuit fault, the feedback voltage of the solenoid valve during a ground short-circuit fault, and the feedback voltage of the solenoid valve during an open-circuit fault, respectively, to obtain the solenoid valve fault diagnosis result, includes:

[0095] The feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a power short circuit fault, the feedback voltage of the solenoid valve when there is a ground short circuit fault, and the feedback voltage of the solenoid valve when there is an open circuit fault, respectively, to obtain the fault diagnosis status of the solenoid valve and the third matching time.

[0096] The third matching time is matched with the preset time. If the third matching time is greater than the preset time, the fault diagnosis result of the solenoid valve is obtained based on the fault diagnosis status. The solenoid valve level status is: low level, medium level and high level.

[0097] It is understandable that the solenoid valve low-side fault diagnosis proposed in this application needs to be analyzed in three main categories:

[0098] 1) First type: When the solenoid valve enable switch is closed:

[0099] (1) When the feedback voltage value is equal to the voltage value after the solenoid valve power supply voltage is divided by R3 and R4 (±5%, which is the error range below and will not be repeated), and the duration exceeds the debouncing preset time, it is confirmed as a normal state and reported to DEM;

[0100] (2) When the feedback voltage value is equal to the voltage value after the solenoid valve power supply voltage is divided by R5, R3 and R4, and the duration exceeds the debouncing preset time, it is confirmed as an open circuit fault of the solenoid valve and the fault is reported to DEM.

[0101] (3) When the feedback voltage value is approximately 0 and the duration exceeds the debouncing preset time, it is confirmed as a short circuit fault to ground of the solenoid valve, and the fault is reported to DEM;

[0102] 2) Second type: When the solenoid valve enable switch is open and the drive duty cycle is 100%:

[0103] (4) When the feedback voltage value is approximately 0 and the duration exceeds the debouncing preset time, it is confirmed as a normal state and the DEM is reported.

[0104] (5) When the feedback voltage value is equal to the voltage value after the solenoid valve power supply voltage is divided by R3 and R4, and the duration exceeds the debouncing preset time, it is confirmed that the solenoid valve is short-circuited to the power supply, and the fault is reported to DEM.

[0105] 3) Third category: When the solenoid valve enable switch is open, the drive duty cycle is not 0 or 100%, let's assume it's D% (the upper and lower limits of D are determined by system requirements):

[0106] (6) If the feedback voltage value is approximately 0 within one PWM cycle and remains so for the entire cycle, it is confirmed as a short circuit fault to ground of the solenoid valve, and the fault is reported to DEM.

[0107] (7) If the feedback voltage value is equal to the voltage value after the solenoid valve power supply voltage is divided by R5, R3 and R4 within one PWM cycle, and lasts for more than one cycle × D% of the time, then the solenoid valve is confirmed to be open circuit fault and the fault is reported to DEM.

[0108] (8) If the feedback voltage value is approximately 5V full scale within one PWM cycle and continues for the entire cycle, it is confirmed as a short circuit fault of the solenoid valve to the power supply, and the fault is reported to DEM.

[0109] (9) If it is not in any of the above three states, then it is determined to be in a normal state and the DEM is reported.

[0110] In some embodiments of the present invention, the fault diagnosis results include:

[0111] Open circuit, short circuit to ground, and short circuit to power supply.

[0112] It is understandable that the fault diagnosis method for the solenoid valve of the commercial vehicle air suspension proposed in this application can effectively distinguish between three types of faults: open circuit, short circuit to ground, and short circuit to power supply.

[0113] In some embodiments of the present invention, the third matching time is obtained through the following steps:

[0114] The feedback voltage of the solenoid valve is continuously matched with a preset voltage threshold to obtain the solenoid valve's level state and the number of times the level state is matched. Based on the number of times the solenoid valve's level state is matched and the obtained solenoid valve fault diagnosis scheduling cycle, the third matching time is obtained.

[0115] In some embodiments of the present invention, the process of obtaining the third matching time based on the number of matching times based on the solenoid valve's level state and the obtained solenoid valve fault diagnosis scheduling cycle includes:

[0116] The third matching time is obtained by multiplying the number of matching times of the solenoid valve's level state by the obtained solenoid valve fault diagnosis scheduling cycle.

[0117] Figure 8 A schematic diagram of an embodiment of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis device provided by the present invention includes:

[0118] The solenoid valve control circuit module 801 is used to acquire the electrical signal of the solenoid valve to be tested collected by the solenoid valve control circuit; the electrical signal of the solenoid valve to be tested is: the feedback voltage and the drive duty cycle of the solenoid valve.

[0119] The matching module 802 is used to continuously match the electrical signal of the solenoid valve to be tested with preset fault diagnosis conditions to obtain the fault diagnosis result of the solenoid valve; the fault diagnosis conditions are: power supply short circuit fault diagnosis condition, ground short circuit fault diagnosis condition and open circuit fault diagnosis condition.

[0120] The commercial vehicle air suspension solenoid valve electrical signal fault diagnosis device 800 provided in the above embodiments can realize the technical solutions described in the above embodiments of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method. The specific implementation principles of each module or unit can be found in the corresponding content in the above embodiments of the commercial vehicle air suspension solenoid valve electrical signal fault diagnosis method, which will not be repeated here.

[0121] The present invention provides a method for diagnosing electrical signal faults in a commercial vehicle air suspension solenoid valve, comprising: acquiring the electrical signal of the solenoid valve to be tested collected by the solenoid valve control circuit; the electrical signal of the solenoid valve to be tested is: the feedback voltage and drive duty cycle of the solenoid valve; continuously matching the electrical signal of the solenoid valve to be tested with preset fault diagnosis conditions to obtain the fault diagnosis result of the solenoid valve; the purpose of this is to match the electrical signal of the solenoid valve to be tested with preset fault diagnosis conditions through fault diagnosis software. The fault diagnosis conditions set by the fault diagnosis software involved in this application mainly involve nine fault state analyses, ultimately realizing fault diagnosis of the solenoid valve under three different operating conditions, with clear and complete diagnostic logic, covering all solenoid valve operating conditions and all possible fault types.

[0122] The above provides a detailed description of the method and device for diagnosing electrical signal faults in the air suspension solenoid valve of commercial vehicles provided by the present invention. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for diagnosing electrical signal faults in a commercial vehicle air suspension solenoid valve, characterized in that, include: Acquire the electrical signal of the solenoid valve to be tested from the solenoid valve control circuit; the electrical signal of the solenoid valve to be tested is: the feedback voltage and drive duty cycle of the solenoid valve. The electrical signal of the solenoid valve to be tested is continuously matched with the preset fault diagnosis conditions to obtain the solenoid valve fault diagnosis results; the fault diagnosis conditions are: power supply short circuit fault diagnosis condition, ground short circuit fault diagnosis condition and open circuit fault diagnosis condition. The step of continuously matching the electrical signal of the solenoid valve to be tested with preset fault diagnosis conditions to obtain the solenoid valve fault diagnosis result includes: The solenoid valve drive duty cycle is matched with a preset duty cycle threshold to determine the solenoid valve enable switch opening and closing state; the solenoid valve enable switch opening and closing states are: closed, open, and periodic opening and closing. With the electromagnetic enable switch in a certain open / closed state, the feedback voltage of the solenoid valve is continuously matched with preset power supply short-circuit fault diagnosis conditions, ground short-circuit fault diagnosis conditions, and open-circuit fault diagnosis conditions to obtain the solenoid valve fault diagnosis results, including: When the solenoid valve enable switch is closed, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a short circuit to ground fault and the feedback voltage of the solenoid valve when there is an open circuit fault, respectively, to obtain the fault diagnosis status of the solenoid valve and the first matching time. The first matching time is compared with the preset debouncing time. If the first matching time is greater than the debouncing time, the solenoid valve fault diagnosis result is obtained based on the fault diagnosis status.

2. The method for diagnosing electrical signal faults in the solenoid valve of a commercial vehicle air suspension according to claim 1, characterized in that, The step of continuously matching the feedback voltage of the solenoid valve with preset power short-circuit fault diagnosis conditions, ground short-circuit fault diagnosis conditions, and open-circuit fault diagnosis conditions, respectively, to obtain the solenoid valve fault diagnosis result, under the determined electromagnetic enable switch open / closed state, further includes: When the solenoid valve enable switch is opened, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when the power supply is short-circuited, so as to obtain the fault diagnosis status and the second matching time of the solenoid valve. The second matching time is compared with the preset debouncing time. If the second matching time is greater than the debouncing time, the solenoid valve fault diagnosis result is obtained based on the fault diagnosis status.

3. The method for diagnosing electrical signal faults in the solenoid valve of a commercial vehicle air suspension according to claim 1, characterized in that, The step of continuously matching the feedback voltage of the solenoid valve with preset power short-circuit fault diagnosis conditions, ground short-circuit fault diagnosis conditions, and open-circuit fault diagnosis conditions, respectively, to obtain the solenoid valve fault diagnosis result, under the determined electromagnetic enable switch open / closed state, further includes: When the solenoid valve enable switch is periodically opened and closed, the feedback voltage of the solenoid valve is continuously matched with the feedback voltage of the solenoid valve when there is a power short circuit fault, the feedback voltage of the solenoid valve when there is a ground short circuit fault, and the feedback voltage of the solenoid valve when there is an open circuit fault, so as to obtain the fault diagnosis status of the solenoid valve and the third matching time. The third matching time is matched with the preset time. If the third matching time is greater than the preset time, the fault diagnosis result of the solenoid valve is obtained based on the fault diagnosis status. The solenoid valve level status is: low level, medium level and high level.

4. The method for diagnosing electrical signal faults in the solenoid valve of a commercial vehicle air suspension according to claim 3, characterized in that, The fault diagnosis results include: Open circuit, short circuit to ground, and short circuit to power supply.

5. The method for diagnosing electrical signal faults in the solenoid valve of a commercial vehicle air suspension according to claim 3, characterized in that, The third matching time is obtained through the following steps: The feedback voltage of the solenoid valve is continuously matched with a preset voltage threshold to obtain the solenoid valve's level state and the number of times the level state is matched. Based on the number of times the solenoid valve's level state is matched and the obtained solenoid valve fault diagnosis scheduling cycle, the third matching time is obtained.

6. The method for diagnosing electrical signal faults in the solenoid valve of a commercial vehicle air suspension according to claim 5, characterized in that, The third matching time is obtained by combining the number of matching attempts based on the solenoid valve's level state and the acquired solenoid valve fault diagnosis scheduling cycle, including: The third matching time is obtained by multiplying the number of matching times of the solenoid valve's level state by the obtained solenoid valve fault diagnosis scheduling cycle.

7. A diagnostic device for electrical signals of a commercial vehicle air suspension solenoid valve, used to perform the diagnostic method for electrical signals of a commercial vehicle air suspension solenoid valve as described in any one of claims 1-6, characterized in that, include: The solenoid valve control circuit module is used to acquire the electrical signal of the solenoid valve under test collected by the solenoid valve control circuit. The electrical signals of the solenoid valve to be tested are: the feedback voltage and the drive duty cycle of the solenoid valve; The matching module is used to continuously match the electrical signal of the solenoid valve to be tested with preset fault diagnosis conditions to obtain the fault diagnosis result of the solenoid valve. The fault diagnosis conditions are: power supply short circuit fault diagnosis condition, ground short circuit fault diagnosis condition, and open circuit fault diagnosis condition.

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