AMT gear selecting position sensor numerical value untrusted fault diagnosis method and system

Abstract

The invention relates to the field of AMT, in particular to an AMT gear selecting position sensor numerical value untrusted fault diagnosis method and system, and the system comprises the steps that an HIL rack simulates the movement process of a piston in an air cylinder through a whole vehicle simulation model, obtains the simulated gear selecting position sensor numerical value, and transmits the simulated gear selecting position sensor numerical value to a TCU; after the TCU receives the numerical value of the gear selecting position sensor simulated by the HIL rack, the target position of a gear selecting executing mechanism is judged according to the valve promoting condition of the AMT gear selecting electromagnetic valve and the gear topological graph; calculating an absolute difference value between the millimeter value of the target position and the simulated numerical value of the gear selecting position sensor; when it is judged that the absolute difference value is larger than a first threshold value, gears with different gear selecting position values are selected according to a gear topological graph, and the fault that the numerical value of a gear selecting position sensor is not credible or the fault that the numerical value of the gear selecting position sensor is stuck occurs is diagnosed; the TCU is helped to simulate and diagnose the untrusted fault of the numerical value of the gear selecting position sensor, and the safety performance of the vehicle is enhanced.

Description

Technical Field

[0001] The present application relates to the technical field of AMT, and in particular to a method and system for diagnosing an AMT gear selection position sensor fault whose numerical value is unreliable. Background Art

[0002] With the rapid development of commercial vehicles, the application of AMT in commercial vehicles is becoming more and more extensive. AMT gearbox is a new type of gearbox structure. By adding an electronic control unit to the traditional manual gearbox, it has the advantages of automatic gear selection and shifting of automatic gearbox, and retains the advantages of high gear transmission efficiency, simple structure and low production cost of manual gearbox. Because the electronic control unit (TCU) of AMT gearbox collects signals such as engine speed, vehicle speed and clutch, gear selection and shifting actuator position to keep track of vehicle status at all times and perform a series of gearbox operations such as starting and shifting.

[0003] Therefore, once some of the signals are wrong, it will affect the judgment of the TCU, causing problems in the gear selection and shifting process, thereby affecting the normal driving process and even causing vehicle safety problems. The TCU receives many signals, including hard-wired signals and message signals. There are many reasons for the errors in these signals. For different reasons for the errors in different signals, the corresponding control strategies and processing methods are naturally different. Therefore, how to discover the cause of the fault, that is, fault diagnosis, is very critical. Correct fault diagnosis can help the TCU make correct processing in the case of the corresponding fault to protect the safety of the driver and the vehicle. At the same time, correct fault diagnosis also provides great convenience for subsequent maintenance work.

[0004] The existing commonly used fault diagnosis mainly focuses on the electrical fault level, such as solenoid valve open circuit, short circuit fault, sensor open circuit, short circuit fault, etc., but there is not much involvement in the rational faults such as sensor value stagnation and value unreliability. Because the working conditions of the vehicle are diverse, it may happen that the sensor has no electrical fault, but the sensor value is stuck or the value is unreliable, causing the TCU to receive wrong information and affecting the normal driving of the vehicle. If the position sensor value is unreliable, it will cause errors in the gear shifting process and fail to shift gears correctly, thus affecting the driving of the vehicle. Summary of the invention

[0005] In order to solve the problem that sensor values ​​are stuck or unreliable, causing the TCU to receive erroneous information and thus affecting the normal driving of the vehicle, the present invention provides an AMT gear selection position sensor value unreliable fault diagnosis method and system.

[0006] In a first aspect, the technical solution of the present invention provides a method for diagnosing an AMT gear selection position sensor value unreliable fault, comprising the following steps: S1: TCU receives the gear position sensor value after HIL bench simulation; S2: Determine whether the AMT fails to shift or is out of gear; If yes, go to step S3; If not, it is determined that no fault has occurred; S3: Determine whether an electrical fault occurs; If so, the corresponding fault is determined; If not, proceed to step S4; S4: according to the valve-promoting condition of the AMT gear selection solenoid valve and the gear position topology diagram, the target position of the gear selection actuator is determined; S5: Calculate the absolute difference between the millimeter value of the target position and the simulated gear selection position sensor value; S6: Determine whether the absolute difference is greater than a first threshold; If yes, go to step S7; If not, it is determined that a mechanical structure failure has occurred; S7: Diagnose a fault in which the value of the gear selection position sensor is unreliable or a fault in which the value of the gear selection position sensor is stuck by selecting a gear with different gear selection position values ​​according to the gear topology diagram.

[0007] From preliminary judgment of whether the AMT has shift failure or gear slip, to troubleshooting electrical faults, to in-depth analysis of the positional relationship of the gear selection actuator, and finally accurate diagnosis of sensor value unreliability or stuck faults, this step-by-step diagnosis method can quickly and accurately locate the fault type, help the TCU to respond correctly in time, ensure the normal operation of the vehicle's shift system, reduce vehicle abnormalities caused by sensor failures, and improve vehicle driving safety and stability. At the same time, it provides clear guidance for subsequent maintenance personnel to find and solve faults, reducing the difficulty and time cost of maintenance.

[0008] As a preferred embodiment of the technical solution of the present invention, before S1, the following is included: S01: TCU receives the shift request and sends a PWM signal to the corresponding solenoid valve according to the control logic to control the switch of the solenoid valve; S02: The HIL test bench receives the switch signal of the solenoid valve of the gear selection actuator sent by the TCU; S03: simulating the movement process of the piston in the cylinder based on the received switch signal, and calculating the position of the piston in the cylinder according to the kinematic formula to obtain the position value of the gear selection actuator; S04: Convert the position value into a millimeter value of a gear selection actuator, process the millimeter value to obtain a simulated gear selection position sensor value, and transmit it to the TCU.

[0009] By clarifying the process of TCU sending control signals, HIL test bench receiving and simulating piston movement to generate sensor values, the data source based on which the diagnosis is based is guaranteed to be reliable. This not only helps to accurately simulate the working conditions of the sensors in actual vehicle operation, but also enables fault diagnosis to be based on real and effective data, further improving the accuracy and reliability of fault diagnosis and enhancing the practicality of the diagnostic method.

[0010] As a preferred embodiment of the technical solution of the present invention, a whole vehicle simulation model is provided in the HIL test bench, and S03 specifically includes: The HIL test bench receives the switching signal of the solenoid valve of the gear selector actuator sent by the TCU and transmits it to the vehicle simulation model. The vehicle simulation model simulates the movement process of the piston in the cylinder, and calculates the position of the piston in the cylinder based on the atmospheric pressure corresponding to the switching signal of the solenoid valve combined with the kinematic formula to obtain the position value of the gear selector actuator.

[0011] The simulation process is more scientific and reasonable, making full use of the simulation function of the HIL test bench. It can more accurately simulate the physical process of the actual operation of the vehicle, providing technical support for generating accurate simulation values ​​of the gear selector position sensor, thereby improving the accuracy and credibility of the entire fault diagnosis method and helping to diagnose faults more accurately.

[0012] As a preferred embodiment of the technical solution of the present invention, S04 specifically includes: According to a preset position-millimeter value mapping table, the position value is converted into a millimeter value of the actuator; The millimeter value is multiplied by a set coefficient to obtain a simulated gear selection position sensor value, which is transmitted to the TCU; the simulated gear selection position sensor value is defined as the actual value.

[0013] The preset position-millimeter value mapping table ensures the accurate conversion of position value to actual physical quantity. The method of multiplying the set coefficient to simulate the fault value is simple and effective. Defining the simulated value as the actual value unifies the data standard and facilitates subsequent calculation and judgment. These steps further refine the simulation process, make the diagnostic method more operable, ensure the accuracy of the diagnostic basis, and help improve the efficiency and accuracy of fault diagnosis.

[0014] As a preferred embodiment of the technical solution of the present invention, in S4, the valve-promoting conditions of the AMT shift selection solenoid valve include: When the extension valve is opened, the gear selection actuator reaches the extension position; When the retract valve opens, the gear selection actuator reaches the retracted position; When the extension valve and the retraction valve are opened at the same time, the gear selection actuator reaches the middle position; S4 specifically includes: The TCU obtains the current gear information and determines the target position of the gear selection actuator based on the valve activation status of the AMT gear selection solenoid valve and the gear topology diagram.

[0015] This enables the TCU to more accurately grasp the expected state of the gear selector actuator during the diagnosis process, providing a more accurate basis for subsequent calculation of position difference and fault judgment. It enhances the logic and accuracy of the diagnostic method, helps to more reliably identify faults, and improves the reliability and stability of vehicle shift control.

[0016] As a preferred embodiment of the technical solution of the present invention, S7 specifically includes: S71: When the original gear position is the first position, select the corresponding first type of gear position. If a gear position other than the first type of gear position is selected, execute S72; S72: Determine whether the change value of the actual value of the gear selection actuator is greater than a second threshold; If not, it is determined that the gear selection position sensor value is stuck; If yes, execute S73; S73: Determine whether the difference between the actual value after the change and the target position value is greater than a first threshold; If so, it is determined that the gear selection position sensor value is unreliable; If not, it is determined that a mechanical structure failure has occurred.

[0017] Selecting a specific gear for testing according to different original gear situations can detect sensor faults more specifically. By judging the actual value change and the difference with the target position value, it can more accurately distinguish between unreliable value faults, jamming faults and mechanical structure faults of the gear position sensor, providing the TCU with more detailed fault information, facilitating it to take more reasonable countermeasures, and also providing maintenance personnel with clearer fault diagnosis results, facilitating targeted maintenance.

[0018] The method provided in this application can accurately diagnose the fault of unreliable value of the gear selector position sensor and provide accurate fault information for the TCU. The TCU can optimize its own control strategy based on this information and make more reasonable and correct handling when encountering a fault, such as timely adjusting the gear shift logic, issuing a fault alarm, etc., thereby improving the control logic of the TCU and improving the overall performance and safety of the vehicle. Fast and accurate fault diagnosis results can help maintenance personnel quickly determine the cause and location of the fault, reduce unnecessary troubleshooting work, and reduce maintenance time and cost. For maintenance technicians, clear and definite fault diagnosis conclusions also reduce the difficulty of maintenance, improve maintenance efficiency and quality, and enable the vehicle to return to normal operation faster.

[0019] In a second aspect, the technical solution of the present invention further provides an AMT gear selection position sensor value unreliable fault diagnosis system, comprising a HIL bench and a TCU; a whole vehicle simulation model is arranged in the HIL bench; The TCU receives the shift request and sends a PWM signal to the corresponding solenoid valve according to the control logic to control the switch of the solenoid valve; after receiving the value of the gear selection position sensor simulated by the HIL bench, the TCU determines the target position of the gear selection actuator according to the valve-promoting condition of the AMT gear selection solenoid valve and the gear topology diagram; calculates the absolute difference between the millimeter value of the target position and the simulated gear selection position sensor value; when it is determined that the absolute difference is greater than the first threshold, the gear with a different gear selection position value is selected according to the gear topology diagram to diagnose the occurrence of an unreliable gear selection position sensor value fault or a stuck gear selection position sensor value fault; The HIL test bench receives the switching signal of the solenoid valve of the gear selector actuator sent by the TCU; based on the received switching signal, the movement process of the piston in the cylinder is simulated through the whole vehicle simulation model to obtain the position of the piston in the cylinder, that is, the position value of the gear selector actuator, and then the simulated gear selector position sensor value is obtained and transmitted to the TCU.

[0020] As a preferred embodiment of the technical solution of the present invention, an I / O module is also provided in the HIL rack; The vehicle physical model simulates the movement of the actuator in the cylinder according to the switch signal of the solenoid valve, obtains the position value of the actuator, converts the position value into the millimeter value of the actuator and sends it to the I / O module; The I / O module multiplies the millimeter value by a set coefficient to obtain a simulated gear selection position sensor value and sends it to the TCU.

[0021] As a preferred embodiment of the technical solution of the present invention, the system further includes a host computer, which issues a gear shift request and sends it to the TCU via a CAN message.

[0022] As a preferred embodiment of the technical solution of the present invention, after the TCU receives the gear select position sensor value simulated by the HIL bench, it first determines whether the AMT fails to shift or is out of gear; if not, it determines that no fault occurs; if so, it determines whether electrical faults occur in each solenoid valve and sensor; if so, the corresponding fault is determined; if not, the target position of the gear select actuator is determined based on the valve activation condition of the AMT gear select solenoid valve and the gear topology diagram.

[0023] As a preferred embodiment of the technical solution of the present invention, when the original gear position is the first position, the corresponding first type of gear position is selected. If a gear position other than the first type of gear position is selected, it is determined whether the change value of the actual value of the gear selection actuator is greater than the second threshold value; if not, it is determined that a gear selection position sensor value stuck fault occurs; if so, it is determined whether the difference between the actual value after the change and the target position value is greater than the first threshold value; if so, it is determined that a gear selection position sensor value unreliable fault occurs; if not, it is determined that a mechanical structure fault occurs.

[0024] It can be seen from the above technical solutions that the present application has the following advantages: helping the TCU to more quickly and correctly simulate and diagnose the fault of unreliable value of the gear selector position sensor, helping to improve the control logic of the TCU, and enhancing the safety performance of the vehicle.

[0025] Fault simulation and diagnosis based on the HIL bench avoids the safety risks that may be caused by reproducing fault conditions in the real vehicle environment. The unreliable value fault of the gear position sensor simulated in the real vehicle can easily cause abnormal gear selection and shifting of the vehicle, endangering the safety of the driver and the vehicle; while the HIL bench can simulate faults in a safe laboratory environment, effectively avoiding such risks and providing safety guarantees for diagnostic work. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic diagram of a flow chart of a method provided in an embodiment of the present invention.

[0028] Figure 2 A block diagram of a system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, features and advantages of this application more obvious and easy to understand, the technical solution protected by this application will be clearly and completely described below using specific embodiments and drawings. Obviously, the embodiments described below are only part of the embodiments of this application, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0030] like Figure 1 As shown, an embodiment of the present invention provides a method for diagnosing an AMT gear selection position sensor value unreliable fault, comprising the following steps: S1: TCU receives the gear position sensor value after HIL bench simulation; S2: Determine whether the AMT fails to shift or is out of gear; If yes, go to step S3; If not, it is determined that no fault has occurred; S3: Determine whether an electrical fault occurs; If so, the corresponding fault is determined; If not, proceed to step S4; S4: according to the valve-promoting condition of the AMT gear selection solenoid valve and the gear position topology diagram, the target position of the gear selection actuator is determined; S5: Calculate the absolute difference between the millimeter value of the target position and the simulated gear selection position sensor value; S6: Determine whether the absolute difference is greater than a first threshold; If yes, go to step S7; If not, it is determined that a mechanical structure failure has occurred; S7: Diagnose a fault in which the value of the gear selection position sensor is unreliable or a fault in which the value of the gear selection position sensor is stuck by selecting a gear with different gear selection position values ​​according to the gear topology diagram.

[0031] It should be noted that, in the embodiment of the present invention, before S1, it is necessary to complete the simulation of the unreliable value fault of the AMT gear selection position sensor based on the HIL bench, which specifically includes: S01: TCU receives the shift request and sends a PWM signal to the corresponding solenoid valve according to the control logic to control the switch of the solenoid valve; S02: The HIL test bench receives the switch signal of the solenoid valve of the gear selection actuator sent by the TCU; S03: simulating the movement process of the piston in the cylinder based on the received switch signal, and calculating the position of the piston in the cylinder according to the kinematic formula to obtain the position value of the gear selection actuator; S04: Convert the position value into a millimeter value of a gear selection actuator, process the millimeter value to obtain a simulated gear selection position sensor value, and transmit it to the TCU.

[0032] The HIL test bench system includes: hardware-in-the-loop test system, vehicle simulation model, TCU, AMT-related actuators, etc. The interaction between TCU and the test bench is through the hard-wire harness and CAN line communication between the test bench and TCU. The vehicle simulation model simulates the engine, sensors, instruments and other mechanisms to send corresponding hard-wire signals and message signals to TCU, and receives hard-wire signals and message signals from TCU.

[0033] The specific process of simulating the gear selection position sensor value is as follows: The HIL test bench receives the switch signal of the electromagnetic valve of the gear selection actuator sent by the TCU and transmits it to the vehicle simulation model. The vehicle simulation model simulates the movement process of the piston in the cylinder, and calculates the position of the piston in the cylinder according to the atmospheric pressure corresponding to the switch signal of the electromagnetic valve in combination with the kinematic formula to obtain the position value of the gear selection actuator. According to the preset position-millimeter value mapping table, the position value is converted into the millimeter value of the actuator; the millimeter value is multiplied by the set coefficient to obtain the simulated gear selection position sensor value and transmitted to the TCU; the simulated gear selection position sensor value is defined as the actual value.

[0034] Since the sensors of the HIL test bench are simulated, their values ​​are calculated based on the vehicle simulation model. The calculation process is as follows: the test bench first receives the switch signals of the two valves of the gear selection actuator sent by the TCU, and simulates the movement of the piston in the cylinder. When the valve is open, it can be considered that the input air supply pressure on this side is about 10 atmospheres, and when the valve is closed, it can be considered that the injected air supply pressure on this side is 1 atmosphere. The position of the piston in the cylinder can be calculated according to the kinematic formula. Through F=P×S, the force of the gas pushing the piston to move when the corresponding valve is opened can be obtained, and then the force minus the friction and other resistances can be used to obtain the resultant force on the piston, and then the acceleration of the piston movement can be obtained according to F=m×a. Then, the acceleration is integrated with time to obtain the speed, and the speed is integrated with time to obtain the displacement of the piston, so that the position of the piston in the cylinder is obtained, that is, the position value of the gear selection actuator (the position value at this time ranges from 0 to 1). Then query the table of position value to millimeter value to obtain the actual millimeter value of the gear selection actuator.

[0035] Therefore, in order to simulate the unreliable value failure of the AMT gear selector position sensor, it is necessary to calculate the correct sensor value in the vehicle simulation model and transmit it to the I / O module and then multiply this value by a coefficient (such as 1.2). In this way, the gear selector position sensor can still send the gear selector position value to the TCU normally, but this value is not the correct position of the gear selector actuator at this time.

[0036] In some embodiments, in S4, the valve-promoting condition of the AMT shift selection solenoid valve includes: The gear selector actuator has three position values: extended, middle, and retracted. When the extension valve is open, the gear selector actuator will reach the extended position; when the retract valve is open, the gear selector actuator will reach the retracted position; when the extension valve and the retract valve are opened at the same time, the gear selector actuator will reach the middle position. S4 specifically includes: The TCU obtains the current gear information and determines the target position of the gear selection actuator based on the valve activation status of the AMT gear selection solenoid valve and the gear topology diagram.

[0037] The memory values ​​of each position of the gear selector actuator during the large learning are used as the target values ​​of the gear selector actuator. Because the vehicle will undergo a large learning when it just rolls off the assembly line, the valve will be activated according to the control logic at this time. The actual position value of the gear selector of this transmission is recorded by activating the two valves of the gear selector actuator. The extension valve and the retraction valve are activated separately to obtain the extension and retraction positions of the gear selector actuator. At the same time, the two valves are activated to obtain the middle position of the gear selector actuator. These three position values ​​are then recorded in the internal variables as the memory values ​​of each position of the gear selector actuator. The difference between the target position and the actual position of the gear selector actuator is calculated using the formula: X_deviation=|X_target-X_actual|. If X_deviation is less than 1.5mm, it can be basically determined that the fault is caused by mechanical structure reasons; if X_deviation is greater than 1.5mm, proceed to the next step.

[0038] S7 specifically includes: S71: When the original gear position is the first position, the corresponding first type of gear position is selected. If a gear position other than the first type of gear position is selected, step S72 is executed; S72: Determine whether the change value of the actual value of the gear selection actuator is greater than a second threshold; If not, it is determined that the gear selection position sensor value is stuck; If yes, execute step S73; S73: Determine whether the difference between the actual value after the change and the target position value is greater than a first threshold; If so, it is determined that the gear selection position sensor value is unreliable; If not, it is determined that a mechanical structure failure has occurred.

[0039] Specifically, according to the gear topology diagram combined with the current slope, input shaft speed, throttle opening, etc., try to select gears with different gear selection position values ​​to further diagnose the fault. Because the gear selection logic of AMT is to calculate the target upshift point and target downshift point of each gear according to factors such as throttle opening, slope, load, curvature, etc. Downshift can be achieved when the input shaft speed is greater than the target downshift point at this time. In order to diagnose the cause of the fault, gears with different gear selection position values ​​are selected according to the gear topology diagram. If the original gear is in the extended position, the retracted or intermediate position gear is selected. If the actual position value of the gear selection actuator changes significantly when other gear selection position values ​​are selected and X_deviation is greater than 1.5mm, it is determined that the gear selection position sensor value is unreliable. If the actual position value of the gear selection actuator does not change significantly when other gear selection position values ​​are selected, it can be determined that the gear selection position sensor value is stuck. The large change here means that the change in the actual position value should be greater than 6mm. That is, according to the gear topology diagram combined with the current slope, input shaft speed, throttle opening, etc., try to shift into a gear with different gear select position values; if when selecting a gear with other gear select position values, the actual position value change of the gear select actuator is greater than 6mm and the absolute difference is greater than 1.5mm, it is determined that a gear select position sensor value unreliable fault occurs; if when selecting a gear with other gear select position values, the actual position value change of the gear select actuator is not greater than 6mm, it is determined that a gear select position sensor value stuck fault occurs.

[0040] The method provided in this application can accurately diagnose the fault of unreliable value of the gear selector position sensor and provide accurate fault information for the TCU. The TCU can optimize its own control strategy based on this information and make more reasonable and correct handling when encountering a fault, such as timely adjusting the gear shift logic, issuing a fault alarm, etc., thereby improving the control logic of the TCU and improving the overall performance and safety of the vehicle. Fast and accurate fault diagnosis results can help maintenance personnel quickly determine the cause and location of the fault, reduce unnecessary troubleshooting work, and reduce maintenance time and cost. For maintenance technicians, clear and definite fault diagnosis conclusions also reduce the difficulty of maintenance, improve maintenance efficiency and quality, and enable the vehicle to return to normal operation faster.

[0041] In the embodiment of the present invention, the correspondence between the position value and the millimeter value is clarified in advance to establish a position-millimeter value mapping table, as shown in Table 1. When the gear selection position is retracted, the position value of 0 corresponds to 35 mm, when the gear selection position is middle, the position value of 0.5 corresponds to 23 mm, and when the gear selection position is extended, the position value of 1 corresponds to 5 mm.

[0042] Table 1: Position-millimeter value mapping table

[0043] Continuously collect information such as the current slope, input shaft speed, throttle opening, etc. of the vehicle, and record the current position value of the gear selector actuator and its corresponding millimeter value. These data are collected by the corresponding sensors and transmitted to the TCU (transmission control unit). Based on the collected information such as the current slope, input shaft speed, throttle opening, etc., the TCU queries the gear topology map to determine the gear selector position value that can be attempted to be engaged under the current working condition and is different from the current gear. The gear topology map specifies the gear selector position corresponding to each gear under different working conditions. The TCU sends a command to the gear selector actuator of the AMT (automatic mechanical transmission) to try to engage the selected gear. During the gear engagement process, the position value change of the gear selector actuator is continuously monitored and converted into millimeter values. The actual position millimeter value of the gear selector actuator before and after the gear engagement is recorded. The actual position value change (millimeter value) of the gear selector actuator and the absolute difference between the millimeter value of the target position of the gear selector actuator and the millimeter value of the current actual position are calculated. If the actual position value of the gear selector actuator changes by more than 6 mm, and the absolute difference is greater than 1.5 mm, it is determined that the gear selector position sensor value is unreliable. If the actual position value of the gear selector actuator does not change by more than 6 mm, it is determined that the gear selector position sensor value is stuck.

[0044] For example, a vehicle equipped with an AMT (automatic mechanical transmission) is driving and is currently in the 3rd gear. The gear selector actuator position value is 0.5, and the corresponding millimeter value is 23 mm. The current slope is 3% (measured by the slope sensor), the input shaft speed is 1800rpm (measured by the speed sensor), and the throttle opening is 35% (measured by the throttle position sensor). The TCU (transmission control unit) queries the gear topology map based on the currently collected information such as the slope, input shaft speed, and throttle opening. Combined with the current vehicle operating conditions, it is determined that it is appropriate to try to shift into the 4th gear at this time, because the gear selector actuator position value corresponding to the 4th gear is 0, and the corresponding millimeter value is 35 mm, which is different from the current 3rd gear selector position value. The TCU sends a command to the AMT's gear selector actuator to try to shift from the 3rd gear to the 4th gear. After the TCU issues a gear shift command, the gear selector position sensor feeds back the actual position value of the gear selector actuator in real time. After the gear shift operation is completed, the millimeter value corresponding to the actual position value fed back by the sensor is 27 mm. The actual position value changes to = 4 mm. Since the actual position should change toward the target position (4th gear corresponds to 35 mm) during the gear shifting process, the actual position value change compared with the target position is recalculated as =12 mm, which is greater than 6 mm. The target position millimeter value is 35 mm, the current actual position millimeter value is 27 mm, and the absolute difference is =8 mm, which is greater than 1.5 mm. Because the actual position value of the gear selector actuator changes by more than 6 mm, and the absolute difference is greater than 1.5 mm, the TCU determines that the gear selector position sensor value is unreliable.

[0045] At this time, the TCU will trigger the corresponding fault alarm mechanism, such as lighting up the fault indicator light on the instrument panel, and storing the fault code in the vehicle's fault memory to facilitate subsequent maintenance personnel to troubleshoot. If the actual position value fed back by the gear position sensor has hardly changed after the TCU issues a command to shift into 4th gear. After the gear shifting operation is completed, the millimeter value corresponding to the actual position value is still 23.5 mm. At this time, the actual position value changes to =0.5 mm, not more than 6 mm. As the actual position value of the gear selector actuator does not change by more than 6 mm, the TCU determines that the gear selector position sensor value is stuck. Subsequently, the TCU will take appropriate fault handling measures, such as issuing a specific alarm sound, and record the fault information for reference during subsequent maintenance.

[0046] like Figure 2 As shown, an embodiment of the present invention further provides an AMT gear selection position sensor value unreliable fault diagnosis system, comprising a HIL bench and a TCU; a whole vehicle simulation model is arranged in the HIL bench; The TCU receives the shift request and sends a PWM signal to the corresponding solenoid valve according to the control logic to control the switch of the solenoid valve; after receiving the value of the gear selection position sensor simulated by the HIL bench, the TCU determines the target position of the gear selection actuator according to the valve-promoting condition of the AMT gear selection solenoid valve and the gear topology diagram; calculates the absolute difference between the millimeter value of the target position and the simulated gear selection position sensor value; when it is determined that the absolute difference is greater than the first threshold, the gear with a different gear selection position value is selected according to the gear topology diagram to diagnose the occurrence of an unreliable gear selection position sensor value fault or a stuck gear selection position sensor value fault; The HIL test bench receives the switching signal of the solenoid valve of the gear selector actuator sent by the TCU; based on the received switching signal, the movement process of the piston in the cylinder is simulated through the whole vehicle simulation model to obtain the position of the piston in the cylinder, that is, the position value of the gear selector actuator, and then the simulated gear selector position sensor value is obtained and transmitted to the TCU.

[0047] In the embodiment of the present invention, an I / O module is also provided in the HIL rack; The vehicle physical model simulates the movement of the actuator in the cylinder according to the switch signal of the solenoid valve, obtains the position value of the actuator, converts the position value into the millimeter value of the actuator and sends it to the I / O module; The I / O module multiplies the millimeter value by a set coefficient to obtain a simulated gear selection position sensor value and sends it to the TCU.

[0048] The system also includes a host computer, which issues a gear shift request and sends it to the TCU via a CAN message.

[0049] It should be noted that after receiving the gear selection position sensor value simulated by the HIL bench, the TCU first determines whether the AMT fails to shift or disengages; if not, it is determined that there is no fault; if so, it is determined whether there is an electrical fault in each solenoid valve and sensor; if so, the corresponding fault is determined; if not, the target position of the gear selection actuator is determined based on the valve-promoting condition of the AMT gear selection solenoid valve and the gear position topology diagram. When the original gear position is the first position, the corresponding first-class gear position is selected. If a gear position other than the first-class gear position is selected, it is determined whether the change value of the actual value of the gear selection actuator is greater than the second threshold; if not, it is determined that the gear selection position sensor value is stuck; if so, it is determined whether the difference between the actual value after the change and the target position value is greater than the first threshold; if so, it is determined that the gear selection position sensor value is unreliable; if not, it is determined that a mechanical structure fault occurs.

[0050] The system provided by the embodiment of the present invention is mainly composed of a host computer, a TCU (transmission control unit), and a HIL bench, and each part is connected by a corresponding communication method. Among them, the HIL bench contains a vehicle simulation model and an I / O module. The host computer and the TCU are connected through a CAN bus to send a shift request; the TCU and the HIL bench interact through hard-wired harnesses and CAN line communications to transmit solenoid valve switch signals and simulated gear position sensor values.

[0051] When the vehicle driver has a shifting demand, he operates the upper computer (such as the vehicle's shift control interface), and the upper computer issues a shifting request and sends the request to the TCU in the form of a CAN message. For example, if the driver wants to shift from the current 3rd gear to 4th gear, the upper computer will generate a corresponding shifting request message and send it to the TCU. After receiving the shifting request from the upper computer, the TCU sends a PWM (pulse width modulation) signal to the corresponding solenoid valve according to its own preset control logic to control the switch of the solenoid valve. For example, for this request to shift from 3rd gear to 4th gear, the TCU will determine the solenoid valve of the gear selection actuator that needs to be controlled according to the shifting logic from 3rd gear to 4th gear, and send a PWM signal with a suitable duty cycle to it to control the switch. The TCU sends the switch signal of the solenoid valve of the gear selection actuator to the HIL bench.

[0052] After the vehicle simulation model in the HIL test bench receives the solenoid valve switch signal sent by the TCU, it simulates the movement of the piston in the cylinder. For example, when the valve is open, the input air supply pressure on this side is set to about 10 atmospheres, and when the valve is closed, the air supply pressure injected on this side is set to 1 atmosphere. According to the kinematic formula F =P × S Calculate the force of the gas pushing the piston, and then subtract the friction and other resistance to get the resultant force on the piston. F = m × a The acceleration of the piston movement is obtained, the speed is obtained by integrating the acceleration with respect to time, and the displacement of the piston is obtained by integrating the speed with respect to time, thereby obtaining the position of the piston in the cylinder, that is, the position value of the gear selection actuator. Assuming that the obtained position value is 0, the corresponding millimeter value of the actuator is 35 (it is known that the corresponding position value of the 4th gear is 0, and the corresponding millimeter value of the position value 0 is 35). The vehicle simulation model sends the obtained millimeter value of the actuator to the I / O module.

[0053] The I / O module multiplies the received millimeter value by the set coefficient (such as 1.2) to obtain the simulated gear position sensor value. In this example, the simulated gear position sensor value is millimeters, and send the value to the TCU. After the TCU receives the value of the gear selection position sensor after the HIL bench simulation, it first determines whether the AMT has a gear shift failure or a gear disengagement. For example, it can be judged by monitoring the vehicle's driving status, speed changes and other information. If there is no gear shift failure or gear disengagement, the TCU determines that there is no fault. If there is a gear shift failure or gear disengagement, the TCU then determines whether there is an electrical fault in each solenoid valve and sensor, such as an open circuit, a short circuit, etc. This can be judged by detecting parameters such as voltage and current in the circuit. If a corresponding electrical fault occurs, the TCU determines the corresponding fault and records it. If no electrical fault occurs, the TCU determines the target position of the gear selection actuator based on the valve activation condition of the AMT gear selection solenoid valve and the gear position topology diagram. In this example, the target is 4th gear, the corresponding position value is 0, and the millimeter value of the target position is 35 millimeters. The TCU calculates the absolute difference between the millimeter value of the target position and the simulated gear selection position sensor value, that is, =7 mm.

[0054] Assume that the first threshold is set to 1.5 mm. Since the absolute difference of 7 mm is greater than 1.5 mm, the TCU further diagnoses the fault by selecting a gear with a different gear position value (such as trying to shift into 5th gear) according to the gear topology. If the actual position value of the gear selector actuator changes by more than 6 mm when trying to shift into 5th gear (for example, the actual position moves from the position corresponding to 4th gear to the position corresponding to 5th gear because it is shifting from 4th gear to 5th gear, the position value corresponding to the target position is 0, and the millimeter value of the target position is 35 mm. The TCU calculates the absolute difference between the millimeter value of the target position and the simulated gear position sensor value. Assuming the simulated value is 42 mm, the absolute difference is =7mm, the millimeter value corresponding to the position change is greater than 6), and the absolute difference is still greater than 1.5mm, the TCU determines that the gear selection position sensor value is unreliable. If the actual position value of the gear selection actuator does not change by more than 6mm when trying to engage the 5th gear, the TCU determines that the gear selection position sensor value is stuck.

[0055] Once the TCU determines that a fault has occurred, it will trigger the corresponding fault handling mechanism. For example, the fault indicator light on the vehicle dashboard will light up to remind the driver that there is a problem with the vehicle; at the same time, the fault code will be stored in the vehicle's fault memory, making it convenient for maintenance personnel to use professional equipment to read the fault information and conduct fault detection and repair.

[0056] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for diagnosing an AMT gear selection position sensor value that is unreliable, characterized in that: The steps include: S1: TCU receives the gear position sensor value after HIL bench simulation; S2: Determine whether the AMT fails to shift or is out of gear; If yes, go to S3; If not, it is determined that no fault has occurred; S3: Determine whether an electrical fault occurs; If so, the corresponding fault is determined; If not, go to S4; S4: according to the valve-promoting condition of the AMT gear selection solenoid valve and the gear position topology diagram, the target position of the gear selection actuator is determined; S5: Calculate the absolute difference between the millimeter value of the target position and the simulated gear selection position sensor value; S6: Determine whether the absolute difference is greater than a first threshold; If yes, go to S7; If not, it is determined that a mechanical structure failure has occurred; S7: Diagnose a fault in which the gear position sensor value is unreliable or a fault in which the gear position sensor value is stuck by selecting a gear position with different gear position values ​​according to the gear topology diagram.

2. The AMT gear selection position sensor value unreliable fault diagnosis method according to claim 1, characterized in that: S1 and before include: S01: TCU receives the shift request and sends a PWM signal to the corresponding solenoid valve according to the control logic to control the switch of the solenoid valve; S02: The HIL test bench receives the switch signal of the solenoid valve of the gear selection actuator sent by the TCU; S03: simulating the movement process of the piston in the cylinder based on the received switch signal, and calculating the position of the piston in the cylinder according to the kinematic formula to obtain the position value of the gear selection actuator; S04: Convert the position value into a millimeter value of a gear selection actuator, process the millimeter value to obtain a simulated gear selection position sensor value, and transmit it to the TCU.

3. The AMT gear selection position sensor value unreliable fault diagnosis method according to claim 2, characterized in that: The HIL test bench is equipped with a vehicle simulation model, S03 specifically includes: The HIL test bench receives the switching signal of the solenoid valve of the gear selector actuator sent by the TCU and transmits it to the vehicle simulation model. The vehicle simulation model simulates the movement process of the piston in the cylinder, and calculates the position of the piston in the cylinder based on the atmospheric pressure corresponding to the switching signal of the solenoid valve combined with the kinematic formula to obtain the position value of the gear selector actuator.

4. The AMT gear selection position sensor value unreliable fault diagnosis method according to claim 3, characterized in that: S04 specifically includes: According to a preset position-millimeter value mapping table, the position value is converted into a millimeter value of the actuator; The millimeter value is multiplied by a set coefficient to obtain a simulated gear selection position sensor value, which is transmitted to the TCU; the simulated gear selection position sensor value is defined as the actual value.

5. The AMT gear selection position sensor value unreliable fault diagnosis method according to claim 4, characterized in that: In S4, the valve activation conditions of the AMT selector solenoid valve include: When the extension valve is opened, the gear selection actuator reaches the extension position; When the retract valve opens, the gear selection actuator reaches the retracted position; When the extension valve and the retraction valve are opened at the same time, the gear selection actuator reaches the middle position; S4 specifically includes: The TCU obtains the current gear information and determines the target position of the gear selection actuator based on the valve activation status of the AMT gear selection solenoid valve and the gear topology diagram.

6. The AMT gear selection position sensor value unreliable fault diagnosis method according to claim 5, characterized in that: S7 specifically includes: S71: When the original gear position is the first position, select the corresponding first type of gear position. If a gear position other than the first type of gear position is selected, execute S72; S72: Determine whether the change value of the actual value of the gear selection actuator is greater than a second threshold; If not, it is determined that the gear selection position sensor value is stuck; If yes, execute S73; S73: Determine whether the difference between the actual value after the change and the target position value is greater than a first threshold; If so, it is determined that the gear selection position sensor value is unreliable; If not, it is determined that a mechanical structure failure has occurred.

7. A fault diagnosis system for an AMT gear selection position sensor whose value is unreliable, characterized in that: It includes a HIL bench and a TCU; the HIL bench is provided with a whole vehicle simulation model; The TCU receives the shift request and sends a PWM signal to the corresponding solenoid valve according to the control logic to control the switch of the solenoid valve; after receiving the value of the gear selection position sensor simulated by the HIL bench, the TCU determines the target position of the gear selection actuator according to the valve-promoting condition of the AMT gear selection solenoid valve and the gear topology diagram; calculates the absolute difference between the millimeter value of the target position and the simulated gear selection position sensor value; when it is determined that the absolute difference is greater than the first threshold, the gear with a different gear selection position value is selected according to the gear topology diagram to diagnose the occurrence of an unreliable gear selection position sensor value fault or a stuck gear selection position sensor value fault; The HIL test bench receives the switching signal of the solenoid valve of the gear selector actuator sent by the TCU; based on the received switching signal, the movement process of the piston in the cylinder is simulated through the whole vehicle simulation model to obtain the position of the piston in the cylinder, that is, the position value of the gear selector actuator, and then the simulated gear selector position sensor value is obtained and transmitted to the TCU.

8. The AMT gear selection position sensor value unreliable fault diagnosis system according to claim 7, characterized in that: The HIL bench is also equipped with I / O modules; The vehicle physical model simulates the movement of the actuator in the cylinder according to the switch signal of the solenoid valve, obtains the position value of the actuator, converts the position value into the millimeter value of the actuator and sends it to the I / O module; The I / O module multiplies the millimeter value by a set coefficient to obtain a simulated gear selection position sensor value and sends it to the TCU.

9. The AMT gear selection position sensor value unreliable fault diagnosis system according to claim 8, characterized in that: The system also includes a host computer, which issues a gear shift request and sends it to the TCU via a CAN message.

10. The AMT gear selection position sensor value unreliable fault diagnosis system according to claim 9, characterized in that: After the TCU receives the gear select position sensor value simulated by the HIL bench, it first determines whether the AMT has a gear shift failure or is out of gear; if not, it determines that there is no fault; if so, it determines whether there is an electrical fault in each solenoid valve and sensor; if so, it determines the corresponding fault; if not, it determines the target position of the gear select actuator based on the valve activation condition of the AMT gear select solenoid valve and the gear topology diagram.

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