AMT gearbox countershaft brake fault diagnosis method, device, equipment and medium

Abstract

The invention belongs to the field of AMT hardware fault diagnosis, and particularly relates to an AMT gearbox countershaft brake fault diagnosis method, device and equipment and a medium, and the method comprises the steps: simulating the fault of a countershaft brake on an HIL rack; the HIL rack communicates with the TCU to be tested, and the gear shifting time of the AMT gearbox is obtained in the process of simulating the fault of the countershaft brake; according to the auxiliary shaft brake fault type obtained through simulation and the corresponding AMT gear shifting time, a corresponding relation is established, and a fault diagnosis database is constructed; when the gear shifting time of the real vehicle is larger than a set threshold value, real vehicle fault information is obtained, and whether an auxiliary shaft brake breaks down or not is judged; and if it is determined that the countershaft brake breaks down, the gear shifting time of the current real vehicle is compared with the fault diagnosis database, and the fault mode of the countershaft brake is judged. Systematic diagnosis of the countershaft brake fault is realized, the accuracy and efficiency of fault diagnosis are improved, and the fault can be quickly positioned.

Description

Technical Field

[0001] This application belongs to the field of AMT hardware fault diagnosis, and specifically relates to a method, device, equipment and medium for diagnosing faults of the countershaft brake of an AMT gearbox. Background Art

[0002] With the increasing development of the current commercial vehicle market, the installation volume of electronically controlled mechanical automatic transmissions (AMT) has also increased significantly. Each manufacturer is actively researching and developing its own automatic transmission control unit (TCU). The control of the AMT by the automatic transmission control unit is an important decision to ensure the smoothness, reliability and economy of the AMT gearbox shifting.

[0003] The control logic of the automatic transmission control unit TCU for the gearbox is that the TCU receives sensor signals from the outside world and other related components through external sensors. After the control logic operation inside the TCU, the TCU sends electrical signals to control each actuator to perform upshift and downshift operations. During this process, the smoothness and speed of upshifting and downshifting are a major test for the TCU and the AMT gearbox. The countershaft brake TB can solve this problem well. Under the control of the TCU, during the shifting process, the countershaft brake TB rubs against the countershaft to quickly reduce the countershaft speed, so that it can quickly enter the target gear.

[0004] Currently, during the actual vehicle test, when the TB fails and causes the shifting time to be too long or not smooth, it is impossible to quickly and effectively directly check out the failure mode and failure degree of the countershaft brake TB, and the problem location is slow, which affects the test progress. Summary of the Invention

[0005] In view of the above problems existing in the diagnosis of faults of the countershaft brake of the gearbox, the present invention provides a method, device, equipment and medium for diagnosing faults of the countershaft brake of an AMT gearbox.

[0006] In a first aspect, the technical solution of the present invention provides a method for diagnosing faults of the countershaft brake of an AMT gearbox, including: Simulating the failure of the countershaft brake on the HIL bench; Communicating with the to-be-tested controller TCU through the HIL bench, and obtaining the shifting time of the AMT gearbox during the process of simulating the failure of the countershaft brake; Establishing a corresponding relationship according to the simulated countershaft brake failure type and the corresponding AMT shifting time, and constructing a fault diagnosis database; When the shifting time of the actual vehicle is greater than the set threshold, obtaining the actual vehicle fault information and judging whether it is a countershaft brake fault; If it is determined to be a countershaft brake fault, comparing the current shifting time of the actual vehicle with the fault diagnosis database to judge the fault mode of the countershaft brake.

[0007] As a further limitation of the technical solution of the present invention, the step of simulating a fault of the secondary shaft brake on the HIL test bench comprises: A countershaft brake simulation model is established in the HIL test bench, and countershaft brake failures of different types and degrees are simulated by changing the parameters in the simulation model.

[0008] Establishing a simulation model to simulate faults in the HIL test bench can flexibly and accurately simulate various complex fault conditions. It is not restricted by the actual vehicle environment and conditions and has high repeatability, providing a reliable foundation for subsequent acquisition of accurate fault data and diagnosis.

[0009] As a further limitation of the technical solution of the present invention, the steps of establishing a secondary shaft brake simulation model in the HIL test bench and simulating secondary shaft brake failures of different types and degrees by changing parameters in the simulation model include: Collect the mechanical structure and parameter data of the countershaft brake and establish a simulation model of the countershaft brake; Fault simulation parameters are determined, and based on the determined fault simulation parameters, an over-simulation model is started to simulate countershaft brake faults of different types and degrees.

[0010] The accuracy and reliability of the simulation model are ensured, which can more realistically reflect the performance changes of the countershaft brake under different fault conditions and improve the credibility of fault diagnosis.

[0011] As a further limitation of the technical solution of the present invention, the steps of collecting mechanical structure and parameter data of the secondary shaft brake and establishing a simulation model of the secondary shaft brake include: Collect the mechanical structure and parameter data of the countershaft brake, and obtain the relevant data of the AMT gearbox; According to the mechanical structure of the countershaft brake, its dynamic model is established in the simulation software to simulate the contact and friction behavior between the friction plate and the countershaft during braking; Model the gas path of the secondary shaft brake to describe the flow and pressure changes of the gas in the gas path; Establish a mathematical model of the control valve to describe its opening and closing characteristics and the relationship between the control signal and the valve opening; A control interface is established between the simulation model and the controller TCU under test for signal transmission.

[0012] By modeling from multiple aspects such as mechanical structure, air circuit, control valve and control interface, a complete and accurate secondary shaft brake simulation model is constructed, which can more comprehensively simulate the working state and fault conditions of the secondary shaft brake and provide richer and more accurate data for fault diagnosis.

[0013] As a further limitation of the technical solution of the present invention, the fault simulation parameters include air circuit blockage or breakage faults, and friction plate wear faults; The steps of starting the over-simulation model to simulate different types and degrees of countershaft brake faults based on the determined fault simulation parameters include: By setting the air supply pressure of the simulation model, air circuit blockage or breakage faults are simulated. Among them, the pressure in the air circuit of the simulation model is set to zero to simulate air circuit breakage faults; The braking torque at different wear degrees is calculated in the simulation model to simulate friction plate wear faults.

[0014] Specific simulation methods are formulated for common fault types, making the fault simulation more targeted and operable, capable of accurately simulating the actual fault scenario, and providing effective data for the subsequent establishment of an accurate fault diagnosis database.

[0015] As a further limitation of the technical solution of the present invention, the steps of obtaining the shift time of the AMT transmission during the process of simulating countershaft brake faults by communicating the HIL bench with the controller under test TCU include: The HIL bench and the TCU perform signal interaction through the bus and hard wire, transmit the simulated fault signal to the TCU, the TCU controls the AMT transmission to shift according to the preset logic, and at the same time feeds back the shift-related information to the HIL bench to obtain the shift time.

[0016] The communication between the HIL bench and the TCU and the method of obtaining the shift time are clarified, ensuring that the shift time data can be accurately obtained during the fault simulation process, and providing a reliable data source for the establishment of the fault diagnosis database.

[0017] As a further limitation of the technical solution of the present invention, if it is determined that there is a countershaft brake fault, the steps of comparing the current actual vehicle shift time with the fault diagnosis database to judge the fault mode of the countershaft brake include: Obtain accurate shift time data from the actual vehicle and record the operating conditions of the vehicle during measurement; According to the actual vehicle shift time, retrieve in the fault diagnosis database. After finding the similar data interval, calculate the time difference between the actual vehicle shift time and the time recorded in the database; the smaller the difference, the higher the matching degree; If the matching degree between the actual vehicle shift time and the database record of simulating air circuit blockage or breakage faults is the highest, combined with the operating conditions of the vehicle, it is judged as an air circuit fault; If the matching degree between the actual vehicle shift time and the record of simulating friction plate wear faults is the highest, combined with the operating conditions of the vehicle, it is judged as a friction plate wear fault.

[0018] Improve the accuracy and scientificity of judging the countershaft brake fault mode according to the actual vehicle shift time, and reduce the possibility of misjudgment.

[0019] In a second aspect, the technical solution of the present invention further provides a fault diagnosis device for the countershaft brake of an AMT gearbox, including a fault simulation module, a time acquisition module, a database construction module, a real vehicle fault information acquisition module, and a fault mode matching module; The fault simulation module is used to simulate the faults of the countershaft brake on the HIL bench; The time acquisition module is used to communicate with the to-be-tested controller TCU through the HIL bench, and acquire the shift time of the AMT gearbox during the process of simulating the faults of the countershaft brake; The database construction module is used to establish a corresponding relationship based on the simulated countershaft brake fault types and the corresponding AMT shift times, and construct a fault diagnosis database; The real vehicle fault information acquisition module is used to acquire real vehicle fault information and judge whether it is a countershaft brake fault when the shift time of the real vehicle is greater than the set threshold; The fault mode matching module is used to compare the current shift time of the real vehicle with the fault diagnosis database if it is determined to be a countershaft brake fault, and judge the fault mode of the countershaft brake.

[0020] Modularizing the fault diagnosis process makes the entire diagnosis system have a clear structure, easy to implement and maintain, improves the stability and scalability of the system, and is convenient for integration with other vehicle control systems.

[0021] As a further limitation of the technical solution of the present invention, the fault simulation module is specifically used to establish a countershaft brake simulation model in the HIL bench, and simulate different types and degrees of countershaft brake faults by changing the parameters in the simulation model.

[0022] As a further limitation of the technical solution of the present invention, the fault simulation module includes a simulation model establishment unit and a simulation execution unit; The simulation model establishment unit is used to collect the mechanical structure and parameter data of the countershaft brake, and establish a countershaft brake simulation model; The simulation execution unit is used to determine the fault simulation parameters, and start the simulation model based on the determined fault simulation parameters to simulate different types and degrees of countershaft brake faults.

[0023] As a further limitation of the technical solution of the present invention, the simulation model establishment unit includes a data acquisition sub-module, a dynamic model construction sub-module, a gas circuit model construction sub-module, a control valve model construction sub-module, and a control interface establishment sub-module; The data acquisition sub-module is used to collect the mechanical structure and parameter data of the countershaft brake, and acquire the relevant data of the AMT gearbox; The dynamic model construction sub-module is used to establish its dynamic model in the simulation software according to the mechanical structure of the countershaft brake, and simulate the contact and friction behavior between the friction plate and the countershaft during the braking process; The air circuit model construction sub-module is used to model the air circuit of the countershaft brake and describe the flow and pressure changes of the gas in the air circuit; The control valve model construction sub-module is used to establish the mathematical model of the control valve, describe its opening and closing characteristics, and the relationship between the control signal and the valve opening; The control interface establishment sub-module is used to establish the control interface between the simulation model and the to-be-tested controller TCU for signal transmission.

[0024] As a further limitation of the technical solution of the present invention, the fault simulation parameters include air circuit blockage or breakage faults, and friction plate wear faults; The simulation execution unit is used to simulate the air circuit blockage or breakage fault by setting the supply air pressure of the simulation model. Among them, setting the pressure in the air circuit of the simulation model to zero simulates the air circuit breakage fault; calculating the braking torque under different wear degrees in the simulation model to simulate the friction plate wear fault.

[0025] As a further limitation of the technical solution of the present invention, the steps of obtaining the shift time of the AMT transmission during the process of simulating the countershaft brake fault by communicating with the to-be-tested controller TCU through the HIL bench include: The HIL bench and the TCU perform signal interaction through the bus and hard wire, transmit the simulated fault signal to the TCU, the TCU controls the AMT transmission to shift according to the preset logic, and at the same time feedbacks the shift-related information to the HIL bench to obtain the shift time.

[0026] As a further limitation of the technical solution of the present invention, the fault mode matching module is specifically used to obtain accurate shift time data from the actual vehicle and record the operating conditions of the vehicle during measurement; retrieve in the fault diagnosis database according to the actual vehicle shift time, and calculate the time difference between the actual vehicle shift time and the time recorded in the database after finding the similar data interval; the smaller the difference, the higher the matching degree; if the matching degree between the actual vehicle shift time and the database record of simulating the air circuit blockage or breakage fault is the highest, combined with the operating conditions of the vehicle, it is judged as an air circuit fault; if the matching degree between the actual vehicle shift time and the record of simulating the friction plate wear fault is the highest, combined with the operating conditions of the vehicle, it is judged as a friction plate wear fault.

[0027] In a third aspect, the technical solution of the present invention further provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; the memory stores computer program instructions executable by the at least one processor, and the computer program instructions are executed by the at least one processor so that the at least one processor can execute the AMT gearbox countershaft brake fault diagnosis method as described in the first aspect.

[0028] In a fourth aspect, the technical solution of the present invention further provides a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions cause the computer to execute the AMT gearbox countershaft brake fault diagnosis method as described in the first aspect.

[0029] As can be seen from the above technical solutions, the present application has the following advantages: By simulating faults on the HIL bench, establishing a diagnostic database and combining with in-vehicle fault troubleshooting, a systematic diagnosis of the AMT gearbox countershaft brake fault is achieved, improving the accuracy and efficiency of fault diagnosis, enabling quick fault location, reducing in-vehicle test time and costs, and providing guarantee for the reliable operation of the AMT gearbox. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions of the present application, the drawings required for description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is a schematic flowchart of the method provided by the embodiment of the present invention.

[0032] Figure 2 It is a connection block diagram of the device provided by the embodiment of the present invention. Detailed Embodiments

[0033] In order to make the application purpose, features, and advantages of the present application more obvious and understandable, the technical solutions protected by the present application will be clearly and completely described below by using specific embodiments and the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in this patent, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by this patent.

[0034] As Figure 1 shown, the embodiment of the present invention provides an AMT gearbox countershaft brake fault diagnosis method, including: S1: Simulate the faults of the countershaft brake on the HIL bench; In the embodiment of the present invention, a countershaft brake simulation model is established in the HIL test bench, and different types and degrees of countershaft brake failures are simulated by changing the parameters in the simulation model. The specific steps include: S11: Collect the mechanical structure and parameter data of the countershaft brake, and establish a countershaft brake simulation model; the steps for establishing the simulation model here include: S111: Collect the mechanical structure and parameter data of the countershaft brake, and obtain the relevant data of the AMT gearbox; collecting the countershaft brake data includes the mechanical structure, working principle, design parameters (such as dimensions, mass, moment of inertia, etc.), air circuit system parameters (such as pipe diameter, air pressure range, flow characteristics, etc.), and the material characteristics and friction coefficient of the friction plate, etc. Obtain the relevant data of the AMT gearbox, such as shift logic, torque transmission characteristics, etc., because the operation of the countershaft brake is closely related to the operation of the gearbox. Understand the control strategy and communication protocol of the TCU so that the simulation model can perform effective signal interaction with the TCU.

[0035] S112: According to the mechanical structure of the countershaft brake, establish its dynamic model in the simulation software to simulate the contact and friction behavior between the friction plate and the countershaft during the braking process; S113: Model the air circuit of the countershaft brake to describe the flow and pressure changes of the gas in the air circuit; establish a mathematical model of the control valve to describe its opening and closing characteristics and the relationship between the control signal and the valve opening; Model the air circuit system of the countershaft brake, including components such as the air source, air pipe, and control valve. Use the principles of fluid mechanics and gas dynamics equations to describe the flow and pressure changes of the gas in the air circuit. For example, calculate the gas flow rate and pressure distribution in the air pipe according to Bernoulli's equation and the continuity equation. Establish a mathematical model of the control valve to describe its opening and closing characteristics, as well as the relationship between the control signal and the valve opening.

[0036] S114: Establish a control interface between the simulation model and the TCU to be tested for signal transmission.

[0037] S12: Determine the fault simulation parameters, and based on the determined fault simulation parameters, start the simulation model to simulate different types and degrees of countershaft brake failures. The fault simulation parameters include air circuit blockage or breakage faults, friction plate wear faults; this step specifically includes: Simulate air circuit blockage or breakage faults by setting the supply air pressure of the simulation model; For the air path blockage fault, determine the location and degree of blockage. The degree of blockage can be expressed by the reduction ratio of gas flow or the pressure loss. For example, when simulating different degrees of blockage, the gas flow in the air path can be reduced by 10%, 20%, 30%, etc. respectively. For the air path breakage fault, directly set the pressure in the air path to zero to simulate the situation where the air path is completely disconnected.

[0038] In the simulation model, according to the determined fault simulation parameters, modify the corresponding model parameters. For example, for the air path blockage fault, adjust the gas flow or pressure parameters in the air path; for the friction plate wear fault, modify the friction coefficient parameter. Set different fault simulation scenarios, including the time, duration, and severity of the fault occurrence, etc. For example, it can be simulated that an air path blockage fault suddenly occurs during the gear shifting process, with a duration of 5 seconds and a blockage degree of 30%.

[0039] If the abnormal air pressure is caused by the air source problem, the pressure parameter of the air source in the simulation model can be directly modified. For example, to simulate the reduction of the air source pressure, reduce the air source pressure by a certain proportion, such as reducing by 20%, 50%, etc. The air path leakage will cause the air pressure to drop, and a leakage module can be added to the air path model. By setting parameters such as the size and position of the leakage hole, different degrees of leakage can be simulated. According to the size of the leakage amount, adjust the pressure and flow in the air path.

[0040] Calculate the braking torque under different wear degrees in the simulation model to simulate the friction plate wear fault. It should be noted that the wear of the friction plate will cause changes in its surface material and microstructure, and then the friction coefficient will change. Generally, as the wear intensifies, the friction coefficient will gradually decrease. The braking torque is directly related to the friction coefficient. According to the relationship: It can be seen that the reduction of the friction coefficient will cause the braking torque to decrease, affecting the braking performance of the countershaft brake. Among them is the braking torque (friction torque), is the friction coefficient, is the normal pressure, is the friction radius), through actual friction plate wear experiments, measure parameters such as the friction coefficient and braking torque under different wear degrees. The experiment can be carried out on a special friction and wear testing machine, simulating the actual working conditions of the countershaft brake, and recording the data at different wear stages. According to the collected data and theoretical research, select a suitable mathematical model to describe the change of the friction coefficient with the wear degree. According to the formula Combined with the dynamically adjusted friction coefficient , calculate the friction torque under different wear degrees. The calculated friction torque Input into the dynamic model of the countershaft brake to simulate the impact of different friction torques on the performance of the countershaft brake, such as braking time, braking distance, gear shifting smoothness, etc. Run the simulation model under different wear levels (i.e. different friction torques) and record various performance parameters of the countershaft brake to facilitate subsequent analysis of the impact of different degrees of friction plate wear failure on the system.

[0041] The accuracy and reliability of the simulation model are ensured, which can more realistically reflect the performance changes of the countershaft brake under different fault conditions and improve the credibility of fault diagnosis.

[0042] Establishing a simulation model to simulate faults in the HIL test bench can flexibly and accurately simulate various complex fault conditions. It is not restricted by the actual vehicle environment and conditions and has high repeatability, providing a reliable foundation for subsequent acquisition of accurate fault data and diagnosis.

[0043] By modeling from multiple aspects such as mechanical structure, air circuit, control valve and control interface, a complete and accurate secondary shaft brake simulation model is constructed, which can more comprehensively simulate the working state and fault conditions of the secondary shaft brake and provide richer and more accurate data for fault diagnosis.

[0044] S2: The HIL test bench communicates with the controller TCU to be tested, and obtains the shift time of the AMT transmission in the process of simulating the secondary shaft brake failure. In this step, the HIL test bench and TCU exchange signals through the bus and hard line, and transmit the simulated fault signal to the TCU. The TCU controls the AMT transmission shift after processing according to the preset logic, and feeds back the shift-related information to the HIL test bench to obtain the shift time. The simulation model simulates various failure modes and failure degrees, and the actual vehicle test restores the real fault troubleshooting scenario to the greatest extent.

[0045] S3: Establish a corresponding relationship between the countershaft brake fault type obtained by simulation and the corresponding AMT shift time, and build a fault diagnosis database; based on HIL simulation test and actual vehicle test scenarios, establish a countershaft brake TB failure diagnosis database according to different failure modes and failure degrees.

[0046] S4: when the shift time of the actual vehicle is greater than the set threshold, obtain the actual vehicle fault information to determine whether it is a countershaft brake fault; S5: If it is determined that the secondary shaft brake is faulty, the current actual vehicle shift time is compared with the fault diagnosis database to determine the fault mode of the secondary shaft brake.

[0047] In the embodiment of the present invention, if it is determined that the secondary shaft brake is faulty, the step of comparing the current actual vehicle shift time with the fault diagnosis database and determining the fault mode of the secondary shaft brake includes: Obtain accurate shift time data from the actual vehicle and record the operating conditions of the vehicle during measurement; Retrieve in the fault diagnosis database according to the actual vehicle shift time. After finding a similar data range, calculate the time difference between the actual vehicle shift time and the time recorded in the database; the smaller the difference, the higher the matching degree; If the matching degree between the actual vehicle shift time and the database record simulating the air circuit blockage or breakage fault is the highest, combined with the operating conditions of the vehicle, it is judged as an air circuit fault; If the matching degree between the actual vehicle shift time and the record of the simulated friction plate wear fault is the highest, combined with the operating conditions of the vehicle, it is judged as a friction plate wear fault.

[0048] Improve the accuracy and scientificity of judging the failure mode of the countershaft brake according to the actual vehicle shift time, and reduce the possibility of misjudgment.

[0049] In the embodiment of the present invention, the role of the simulation model is to simulate a virtual vehicle environment, so that the controller under test thinks it is in a real test drive environment. The simulation model runs in the HIL bench, and through the HIL bench and the controller under test TCU, bus and hard wire signal interactions are carried out, so as to reflect the logical processing results of the controller under test when receiving different external signals. Combining the method of the present invention, the failure of the countershaft brake TB usually occurs as the air circuit of the countershaft brake TB is blocked or broken, or the friction plate of the countershaft brake is severely worn, resulting in insufficient braking force, causing the countershaft brake TB to fail, resulting in too long shift time of the AMT transmission, affecting performance such as fuel consumption. Based on the above failure modes of the countershaft brake, the simulation model is used to simulate different failure forms of the countershaft brake TB respectively. First, for the failure mode of the air circuit blockage or breakage of the countershaft brake TB, the simulation model simulates different supply air pressures to simulate the air circuit blockage or breakage situation, and records the AMT shift time under different air pressure supplies in the current failure mode. Second, for the severe wear of the friction plate of the countershaft brake TB, the simulation model simulates different friction torques to simulate the AMT transmission shift time situation under different degrees of friction plate loss.

[0050] According to the above simulation model to simulate different failure modes and degrees of the countershaft brake TB, record the Log files under different failure modes and degrees, analyze the slope of the gear signal change under different failure modes, and construct a countershaft brake TB diagnosis database to facilitate data comparison in actual vehicle tests and lay a foundation for subsequent test projects.

[0051] The real vehicle test process is established. When it is found during real vehicle testing that the shift time is too long, first use the EOL device to read the fault and determine whether the problem is caused by the countershaft brake TB body or the wiring harness connection. Secondly, use the EOL device to perform individual valve actuation to detect the position of the valve and whether it reaches the specified position according to the logic, and determine whether it is a problem with the relevant air circuit of the countershaft brake TB, resulting in insufficient countershaft braking force. Finally, check that there are no problems in the above two places, and compare with the diagnostic database according to the current shift time to determine the failure degree of the fault.

[0052] One implementation process of the method provided by the embodiment of the present invention is as follows: First, build a HIL bench test environment, including preparing HIL bench equipment, installing the controller under test TCU, etc. Use simulation software to establish a fault simulation model of the countershaft brake, simulating faults such as air circuit blockage, breakage, and friction plate wear. During the simulation, collect the shift time data of the AMT transmission through communication between the bench and the TCU. According to the simulated fault types and corresponding shift times, establish a data table and construct a fault diagnosis database. During real vehicle testing, when it is found that the shift time is greater than the set threshold, read the vehicle fault code, check relevant sensors and circuits, etc. to obtain fault information, and determine whether it is a countershaft brake fault. If it is determined to be so, compare the real vehicle shift time with the database to determine the fault mode.

[0053] Based on the built HIL bench, select a suitable simulation software, such as MATLAB / Simulink. Collect detailed mechanical structure parameters of the countershaft brake, such as dimensions, mass, moment of inertia, etc., as well as air circuit system parameters. Establish a model in the simulation software according to the working principle of the countershaft brake. By modifying the parameters in the model, such as air pressure value, friction coefficient, etc., simulate different types and degrees of faults, such as changing the air pressure to simulate air circuit faults and changing the friction coefficient to simulate friction plate wear faults.

[0054] After selecting the simulation software, comprehensively collect relevant data of the countershaft brake and the AMT transmission. In the simulation software, based on the mechanical structure of the countershaft brake, establish a dynamic model using the dynamic equation to simulate the friction behavior between the friction plate and the countershaft. Apply the principles of fluid mechanics to model the air circuit, describing gas flow and pressure changes. Establish a mathematical model of the control valve, defining the relationship between the control signal and the valve opening. Establish a control interface with the TCU. Determine fault simulation parameters such as the degree of air circuit blockage and the degree of friction plate wear, start the simulation model, and change the parameters to simulate different faults. Based on the collected data, in the simulation software, according to the mechanical structure parameters of the countershaft brake, use mass, moment of inertia, etc. to construct a dynamic model, set the friction coefficient to simulate the friction behavior. According to the air circuit structure and the principle of gas flow, establish an air circuit model. According to the characteristics of the control valve, establish a mathematical model to describe the relationship between its opening and closing and the control signal. Based on the TCU communication protocol, establish a control interface model to achieve signal transmission with the TCU.

[0055] In the established simulation model, for the air circuit blockage or breakage fault, by setting the supply air pressure of the simulation model, gradually reduce the air pressure to simulate the air circuit blockage, and set the air pressure to zero to simulate the air circuit breakage. For the friction plate wear fault, according to the relationship between friction plate wear and the friction coefficient, calculate the braking torque at different wear levels, and adjust the braking torque in the simulation model to simulate the friction plate wear. During the process of simulating the fault, connect the HIL bench and the TCU through the bus and hard wire. The HIL bench sends the simulated fault signal to the TCU, and the TCU processes the signal according to the internal preset logic to control the shifting of the AMT transmission. The TCU feeds back the shifting-related information, such as the start and end times of shifting, to the HIL bench, thereby obtaining the shifting time data.

[0056] When the shifting time of the actual vehicle is greater than the set threshold and it is determined that there is a countershaft brake fault, use the vehicle detection equipment to accurately obtain the shifting time and record the operating conditions of the vehicle at that time. In the constructed fault diagnosis database, through the data retrieval algorithm, find the data interval close to the shifting time of the actual vehicle. Calculate the time difference between the shifting time of the actual vehicle and the time recorded in the database, and determine the matching degree according to the size of the difference. Combining the operating conditions of the vehicle, if the matching degree is the highest with the air circuit fault simulation data, it is judged as an air circuit fault; if the matching degree is the highest with the friction plate wear fault simulation data, it is judged as a friction plate wear fault.

[0057] As Figure 2 shown, an embodiment of the present invention also provides a fault diagnosis device for the countershaft brake of an AMT transmission, including a fault simulation module, a time acquisition module, a database construction module, an actual vehicle fault information acquisition module, and a fault mode matching module; The fault simulation module is used to simulate the faults of the countershaft brake on the HIL bench; A time acquisition module, which is used to communicate with the to-be-tested controller TCU through the HIL bench and acquire the shift time of the AMT transmission during the process of simulating the failure of the countershaft brake; A database construction module, which is used to establish a corresponding relationship according to the simulated countershaft brake failure types and the corresponding AMT shift times, and construct a fault diagnosis database; A real vehicle fault information acquisition module, which is used to acquire real vehicle fault information and judge whether it is a countershaft brake failure when the shift time of the real vehicle is greater than the set threshold; A fault mode matching module, which is used to compare the current real vehicle shift time with the fault diagnosis database if it is determined to be a countershaft brake failure, and judge the fault mode of the countershaft brake.

[0058] Modularize the fault diagnosis process, making the entire diagnosis system have a clear structure, easy to implement and maintain, improving the stability and scalability of the system, and facilitating integration with other vehicle control systems.

[0059] Build a diagnostic device hardware platform including a processor, a communication module, etc. In terms of software, develop the functional programs of each module. The fault simulation module calls the method described in the above embodiment to simulate faults on the HIL bench; the time acquisition module acquires the shift time; the database construction module establishes the database; the real vehicle fault information acquisition module acquires the real vehicle fault information; the fault mode matching module judges the fault mode.

[0060] In some embodiments, the fault simulation module is specifically used to establish a countershaft brake simulation model in the HIL bench and simulate different types and degrees of countershaft brake failures by changing the parameters in the simulation model. The fault simulation module includes a simulation model establishment unit and a simulation execution unit; The simulation model establishment unit is used to collect the mechanical structure and parameter data of the countershaft brake and establish a countershaft brake simulation model; The simulation execution unit is used to determine the fault simulation parameters and start the simulation model based on the determined fault simulation parameters to simulate different types and degrees of countershaft brake failures.

[0061] Specifically, the simulation model establishment unit includes a data acquisition sub-module, a dynamics model construction sub-module, a gas circuit model construction sub-module, a control valve model construction sub-module, and a control interface establishment sub-module; The data acquisition sub-module is used to collect the mechanical structure and parameter data of the countershaft brake and acquire the relevant data of the AMT transmission; The dynamics model construction sub-module is used to establish its dynamics model in the simulation software according to the mechanical structure of the countershaft brake and simulate the contact and friction behavior between the friction plate and the countershaft during the braking process; An air circuit model construction sub-module, which is used to model the air circuit of the countershaft brake and describe the flow and pressure changes of the gas in the air circuit; A control valve model construction sub-module, which is used to establish a mathematical model of the control valve, describe its opening and closing characteristics, and the relationship between the control signal and the valve opening; A control interface establishment sub-module, which is used to establish a control interface between the simulation model and the to-be-tested controller TCU for signal transmission.

[0062] In some embodiments, the fault simulation parameters include air circuit blockage or breakage faults, friction plate wear faults; A simulation execution unit, which is used to simulate air circuit blockage or breakage faults by setting the supply air pressure of the simulation model. Among them, setting the pressure in the air circuit of the simulation model to zero simulates an air circuit breakage fault; calculating the braking torque under different wear degrees in the simulation model to simulate friction plate wear faults.

[0063] In some embodiments, when communicating with the to-be-tested controller TCU through the HIL bench, the steps of obtaining the shift time of the AMT gearbox during the process of simulating the countershaft brake fault include: The HIL bench and the TCU perform signal interaction through the bus and hard wire, transmit the simulated fault signal to the TCU, the TCU controls the AMT gearbox to shift gears after processing according to the preset logic, and at the same time feeds back the shift-related information to the HIL bench to obtain the shift time.

[0064] In some embodiments, the fault mode matching module is specifically used to obtain accurate shift time data from the actual vehicle and record the operating conditions of the vehicle during measurement; retrieve in the fault diagnosis database according to the actual vehicle shift time, and calculate the time difference between the actual vehicle shift time and the time recorded in the database after finding a similar data interval; the smaller the difference, the higher the matching degree; if the matching degree between the actual vehicle shift time and the database record of simulating air circuit blockage or breakage faults is the highest, combined with the operating conditions of the vehicle, it is judged as an air circuit fault; if the matching degree between the actual vehicle shift time and the record of simulating friction plate wear faults is the highest, combined with the operating conditions of the vehicle, it is judged as a friction plate wear fault.

[0065] An embodiment of the present invention further provides an electronic device, which includes: a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete mutual communication through the communication bus. The communication bus can be used for information transmission between the electronic device and the sensor. The processor can call the logical instructions in the memory to execute the following method: S1: Simulate the failure of the auxiliary shaft brake on the HIL bench; S2: Communicate with the to-be-tested controller TCU through the HIL bench, and obtain the shift time of the AMT gearbox during the process of simulating the failure of the auxiliary shaft brake; S3: Establish a corresponding relationship according to the simulated auxiliary shaft brake failure type and the corresponding AMT shift time, and construct a fault diagnosis database; S4: When the shift time of the actual vehicle is greater than the set threshold, obtain the actual vehicle fault information and determine whether it is a failure of the auxiliary shaft brake; S5: If it is determined that it is a failure of the auxiliary shaft brake, compare the current shift time of the actual vehicle with the fault diagnosis database to determine the fault mode of the auxiliary shaft brake.

[0066] In addition, when the logical instructions in the above-mentioned memory are implemented in the form of software functional units and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0067] An embodiment of the present invention provides a non-transitory computer-readable storage medium that stores computer instructions, and these computer instructions cause the computer to execute the methods provided in the above method embodiments, for example, including: S1: Simulate the failure of the auxiliary shaft brake on the HIL bench; S2: Communicate with the to-be-tested controller TCU through the HIL bench, and obtain the shift time of the AMT gearbox during the process of simulating the failure of the auxiliary shaft brake; S3: Establish a corresponding relationship according to the simulated auxiliary shaft brake failure type and the corresponding AMT shift time, and construct a fault diagnosis database; S4: When the shift time of the actual vehicle is greater than the set threshold, obtain the actual vehicle fault information and determine whether it is a failure of the auxiliary shaft brake; S5: If it is determined that it is a failure of the auxiliary shaft brake, compare the current shift time of the actual vehicle with the fault diagnosis database to determine the fault mode of the auxiliary shaft brake.

[0068] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those 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. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for diagnosing faults of an AMT gearbox countershaft brake, characterized in that: include: Simulate the failure of the countershaft brake on the HIL test bench; The HIL test bench communicates with the TCU of the controller under test to obtain the shifting time of the AMT transmission during the simulation of the countershaft brake failure. According to the countershaft brake fault type obtained by simulation and the corresponding AMT shift time, a corresponding relationship is established to build a fault diagnosis database; When the shift time of the actual vehicle is greater than the set threshold, the actual vehicle fault information is obtained to determine whether it is a countershaft brake fault; If it is determined that the secondary shaft brake is faulty, the current actual vehicle shift time is compared with the fault diagnosis database to determine the fault mode of the secondary shaft brake.

2. The AMT gearbox countershaft brake fault diagnosis method according to claim 1, characterized in that: The steps to simulate the failure of the countershaft brake on the HIL bench include: A countershaft brake simulation model is established in the HIL test bench, and countershaft brake failures of different types and degrees are simulated by changing the parameters in the simulation model.

3. The AMT gearbox countershaft brake fault diagnosis method according to claim 2, characterized in that: The steps of establishing a countershaft brake simulation model in the HIL test bench and simulating different types and degrees of countershaft brake failures by changing parameters in the simulation model include: Collect the mechanical structure and parameter data of the countershaft brake and establish a simulation model of the countershaft brake; Fault simulation parameters are determined, and based on the determined fault simulation parameters, an over-simulation model is started to simulate countershaft brake faults of different types and degrees.

4. The AMT gearbox countershaft brake fault diagnosis method according to claim 3, characterized in that: The steps of collecting the mechanical structure and parameter data of the countershaft brake and establishing the countershaft brake simulation model include: Collect the mechanical structure and parameter data of the countershaft brake, and obtain the relevant data of the AMT gearbox; According to the mechanical structure of the countershaft brake, its dynamic model is established in the simulation software to simulate the contact and friction behavior between the friction plate and the countershaft during braking; Model the gas path of the secondary shaft brake to describe the flow and pressure changes of the gas in the gas path; Establish a mathematical model of the control valve to describe its opening and closing characteristics and the relationship between the control signal and the valve opening; A control interface is established between the simulation model and the controller TCU under test for signal transmission.

5. The AMT gearbox countershaft brake fault diagnosis method according to claim 4, characterized in that: Fault simulation parameters include air path blockage or breakage fault, friction plate wear fault; The steps of starting the simulation model to simulate different types and degrees of countershaft brake faults based on the determined fault simulation parameters include: By setting the air supply pressure of the simulation model, a gas line blockage or breakage fault is simulated, wherein the pressure in the gas line of the simulation model is set to zero to simulate a gas line breakage fault; The braking torque under different wear degrees is calculated in the simulation model to simulate the friction plate wear.

6. The AMT gearbox countershaft brake fault diagnosis method according to claim 5, characterized in that: The steps of obtaining the shift time of the AMT transmission in the process of simulating the countershaft brake failure by communicating with the controller TCU under test through the HIL test bench include: The HIL test bench and TCU exchange signals through the bus and hard wires, transmitting the simulated fault signal to the TCU. The TCU controls the AMT transmission shifting after processing according to the preset logic, and at the same time feeds back the shifting-related information to the HIL test bench to obtain the shifting time.

7. The AMT gearbox countershaft brake fault diagnosis method according to claim 5, characterized in that: If it is determined that the secondary shaft brake is faulty, the current actual vehicle shift time is compared with the fault diagnosis database, and the steps of determining the fault mode of the secondary shaft brake include: Obtain accurate shift time data from the actual vehicle and record the vehicle's operating conditions during measurement; According to the actual vehicle shifting time, search in the fault diagnosis database, find the similar data interval, and calculate the time difference between the actual vehicle shifting time and the time recorded in the database; the smaller the difference, the higher the matching degree; If the actual vehicle shift time has the highest matching degree with the database record of simulated gas line blockage or breakage fault, combined with the vehicle's operating conditions, it is determined to be a gas line fault; If the actual vehicle shifting time matches the record of the simulated friction plate wear fault most closely, combined with the vehicle's operating conditions, it is determined to be a friction plate wear fault.

8. An AMT gearbox countershaft brake fault diagnosis device, characterized in that: It includes fault simulation module, time acquisition module, database construction module, real vehicle fault information acquisition module and fault pattern matching module; Fault simulation module, used to simulate the fault of the secondary shaft brake on the HIL test bench; The time acquisition module is used to communicate with the controller under test TCU through the HIL test bench to obtain the shift time of the AMT transmission during the simulation of the countershaft brake failure; A database construction module, used to establish a corresponding relationship between the countershaft brake fault type obtained by simulation and the corresponding AMT shift time, and to construct a fault diagnosis database; A real vehicle fault information acquisition module is used to acquire real vehicle fault information when the shift time of the real vehicle is greater than a set threshold value, and determine whether it is a countershaft brake fault; The fault mode matching module is used to compare the current actual vehicle shift time with the fault diagnosis database to determine the fault mode of the countershaft brake if it is determined that the countershaft brake is faulty.

9. An electronic device, characterized in that: The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; the memory stores computer program instructions executable by the at least one processor, and the computer program instructions are executed by the at least one processor so that the at least one processor can execute the AMT transmission countershaft brake fault diagnosis method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, characterized in that: The non-transitory computer-readable storage medium stores computer instructions, and the computer instructions enable the computer to execute the AMT transmission countershaft brake fault diagnosis method as described in any one of claims 1 to 7.

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