A hybrid transmission fault handling gear control method based on mode input

Abstract

The present application relates to gearbox fault processing, in particular to a hybrid gearbox fault processing gear control method based on mode input. The problem that the existing AMT control system fails to solve the gearbox fault processing gear control of the hybrid vehicle in different modes and mode switching of P2 configuration is solved. The faults encountered by the vehicle in different modes are classified. The vehicle operating modes include four modes: the vehicle is stationary and not in the shifting process in the pure electric mode, the vehicle is not stationary and not in the neutral position in the pure electric mode, the vehicle is stationary and not in the shifting process in the hybrid mode, and the vehicle is not stationary and not in the neutral position in the hybrid mode. There are faults that trigger forced return to neutral and prohibit shifting in the hybrid mode, and there are faults that trigger forced return to neutral and prohibit shifting in the pure electric mode. Through condition judgment, the vehicle makes correct decisions on gear under different mode fault conditions.

Description

Technical Field

[0001] The present invention relates to a gearbox fault processing method, and in particular to a hybrid gearbox fault processing gear control method based on mode input. Background Art

[0002] As a green transportation tool that combines both economical and dynamic performance, hybrid vehicles offer unparalleled advantages and competitiveness in the fiercely competitive commercial vehicle market. However, to further enhance the operational stability and risk response capabilities of hybrid vehicles, it is necessary to further optimize hybrid transmission fault handling methods and improve the stability of hybrid automatic transmissions and overall vehicle safety.

[0003] Currently, traditional fuel-powered AMT transmissions use the engine as the power source when troubleshooting, while pure electric vehicles use the motor as the power source. Vehicles with different power sources have different control response methods when troubleshooting. Compared to pure fuel-powered and pure electric vehicles, which have only a single power source, hybrid vehicles have two power sources. Most existing hybrid vehicles typically follow the same "one-size-fits-all" approach to troubleshooting transmission problems as pure fuel-powered and pure electric vehicles. Regardless of the mode, the vehicle must be stopped and the power source shut down to troubleshoot the problem. The biggest difference between hybrid vehicle transmission troubleshooting and pure fuel-powered AMT transmissions and pure electric vehicles is that hybrid vehicles have two power units, each with its own unique troubleshooting mode. The most unique feature is the ability to switch modes. This is especially true for P2 hybrid vehicles, where the motor is located at the transmission input. How to handle transmission faults in different modes and during mode switching presents a technical challenge.

[0004] A Chinese invention patent with authorization publication number CN104950776B discloses a parallel hybrid AMT control system, comprising a drive layer and an application layer. The drive layer includes a CAN communication module, a basic module, and a fault handling module. The CAN communication module implements a communication protocol stack based on CAN2.0B, CCP, and UDS protocols. The basic module implements a basic algorithm library, motor control and protection, and clutch control and protection. The fault handling module performs fault analysis and fault handling functions. The application layer is responsible for implementing various functions at the system business logic level, including a signal processing module and an application function module. Compared to traditional AMT control systems, the parallel hybrid AMT control system provided by the aforementioned invention incorporates an HCU, motor, battery, and its control system. The TCU coordinates with the HCU to control the entire powertrain and transmission system to improve overall system control reliability. However, this control system still fails to properly address the issue of transmission fault handling and gear control in different modes and during mode switching for P2 hybrid vehicles. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problem that the existing AMT control system fails to solve the transmission fault handling gear control of P2 configuration hybrid vehicles in different modes and when switching between modes, and to provide a hybrid transmission fault handling gear control method based on mode input.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A hybrid transmission fault handling gear control method based on mode input is characterized in that it includes the following steps:

[0008] S1. Determine whether the vehicle is in a stationary state. If so, proceed to step S2; if not, proceed to step S8;

[0009] S2, determining whether the vehicle is in the process of shifting gears, if so, returning to step S1, if not, executing step S3;

[0010] S3, determine whether the vehicle is in pure electric mode, if so, execute step S4, if not, execute step S5;

[0011] S4, determining whether the vehicle triggers a pure electric forced return to neutral fault, if so, executing step S6, if not, returning to step S1;

[0012] S5, determining whether the vehicle triggers a hybrid forced return to neutral fault, if so, executing step S6, if not, returning to step S1;

[0013] S6, the gearbox returns to neutral gear, and the vehicle is forced to return to neutral gear;

[0014] S7, confirm whether the vehicle is back to neutral, if so, return to step S1, if not, return to step S6;

[0015] S8, determine whether the vehicle is in neutral, if so, return to step S1, if not, execute step S9;

[0016] S9, determining whether the vehicle is in pure electric mode, if so, executing step S10, if not, executing step 11;

[0017] S10, determining whether the vehicle triggers a pure electric gear shift prohibition fault, if so, executing step S12, if not, returning to step S1;

[0018] S11, determining whether the vehicle triggers a hybrid gear shift prohibition fault, if so, executing step S12, if not, returning to step S1;

[0019] S12: The gearbox prohibits the gear shifting operation and forces the vehicle to maintain the current gear;

[0020] S13: Confirm whether the vehicle responds to the prohibition of shifting. If not, return to step S12 for execution. If so, stop the vehicle by braking and wait for maintenance. After the maintenance is completed, shift the vehicle into the forward gear and return to step S1 to complete the hybrid transmission fault handling gear control based on the mode input.

[0021] Furthermore, step S1 is specifically as follows: the TCU receives the operating status signal through the CAN bus and determines whether the vehicle is in a stationary state. If so, step S2 is executed; if not, step S8 is executed.

[0022] Furthermore, step S2 is specifically as follows: the TCU receives the gear position signal via the CAN bus and determines whether the vehicle is in the gear shifting process. If so, the process returns to step S1; if not, the process proceeds to step S3;

[0023] Step S8 is specifically as follows: the TCU receives the gear signal through the CAN bus and determines whether the vehicle is in neutral. If so, the process returns to step S1; if not, the process proceeds to step S9.

[0024] Furthermore, step S3 is specifically as follows: the TCU receives the vehicle mode signal through the CAN bus and determines whether the vehicle is in the pure electric mode. If so, step S4 is executed; if not, step S5 is executed;

[0025] Step S9 is specifically as follows: the TCU receives the vehicle mode signal through the CAN bus and determines whether the vehicle is in pure electric mode. If so, step S10 is executed; if not, step S11 is executed.

[0026] Furthermore, step S4 is specifically as follows: the TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a pure electric forced return to neutral fault. If so, step S6 is executed; if not, the process returns to step S1.

[0027] Step S10 is specifically as follows: the TCU receives a fault signal through the CAN bus and determines whether the vehicle triggers a pure electric prohibited shift fault. If so, step S12 is executed; if not, the process returns to step S1.

[0028] Furthermore, step S5 is specifically as follows: the TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a hybrid forced return to neutral fault. If so, step S6 is executed; if not, the process returns to step S1.

[0029] Step S11 is specifically as follows: the TCU receives a fault signal through the CAN bus and determines whether the vehicle triggers a hybrid gear shift prohibition fault. If so, step S12 is executed; if not, the process returns to step S1.

[0030] Furthermore, step S6 is specifically as follows: the TCU sends a command to the transmission via the CAN bus to force the target gear to be neutral, and the transmission controls the shift actuator and the clutch actuator to return to neutral, thereby controlling the entire vehicle to be forced to return to neutral;

[0031] Step S12 is specifically as follows: the TCU sends a shift prohibition instruction to the transmission through the CAN bus, and the transmission prohibits the shifting operation by controlling the shift actuator and the clutch actuator, forcing the entire vehicle to maintain the current gear.

[0032] Furthermore, step S7 is specifically as follows: the TCU receives the instrument and gear position signal feedback via the CAN bus to confirm whether the vehicle is back to neutral. If so, the process returns to step S1; if not, the process returns to step S6;

[0033] Step S13 is specifically as follows: the TCU receives instrument and gear signal feedback through the CAN bus to confirm whether the vehicle responds to the prohibition of gear shifting. If not, it returns to execute step S12; if so, the vehicle is stopped by braking and waits for maintenance processing; after the processing is completed, the vehicle is shifted into the forward gear and returns to step S1 to complete a hybrid transmission fault processing gear control based on the mode input.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a hybrid transmission fault handling gear control method based on mode input, which classifies the faults encountered by the whole vehicle in different modes. First, the vehicle operation mode includes four modes: the whole vehicle is stationary and not in the gear shifting process in pure electric mode, the whole vehicle is not stationary and not in neutral in pure electric mode, the whole vehicle is stationary and not in the gear shifting process in hybrid mode, and the whole vehicle is not stationary and not in neutral in hybrid mode. In addition, there are faults that trigger forced return to neutral and prohibit gear shifting in hybrid mode, and there are faults that trigger forced return to neutral and prohibit gear shifting in pure electric mode. Through conditional judgment, the fault conditions of the vehicle in different modes are judged. The correct gear decision can be made under certain conditions. If the hybrid vehicle is in pure electric mode, since the power source comes from the motor at this time, it can still shift gears and drive normally when an engine-related fault occurs; if it is in hybrid mode at this time, it must enter a specific gear restriction mode according to the fault to ensure driving safety. This method provides certain theoretical guidance and technical support for how hybrid vehicles with P2 configuration can complete gear restriction according to the vehicle status and faults in different modes. It has good reference and guiding significance, especially when dealing with faults in the process of mode switching, such as pure electric-hybrid or hybrid-pure electric. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of an embodiment of a hybrid transmission fault handling gear control method based on mode input according to the present invention;

[0037] Figure 2 This is an architecture diagram of a transmission fault processing gear control system designed to implement the hybrid transmission fault processing gear control method based on mode input in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the accompanying drawings and exemplary embodiments.

[0039] Reference Figure 2 The architecture diagram of the transmission fault handling gear control system shown in the figure shows that the main input signals in this system include vehicle mode signals (including pure electric mode and hybrid mode), operating status signals, fault signals (including speed faults, air pressure faults, engine faults, clutch faults, partial message loss, and bus signal faults), gear signals, clutch status signals, engine ECU (electronic control unit) signals, handle signals, and instrument signals. Both the HCU (hybrid control unit) and TCU (transmission control unit) interact with these signals via the CAN bus. The TCU can control the target gear control in different modes and different vehicle operating states in conjunction with the fault handling program. It can change gears by controlling the transmission's gear actuator and clutch actuator, and realize the function of prohibiting gear shifting or forcing the return to neutral in fault conditions. The function is also fed back to the vehicle and instrument via the CAN bus.

[0040] The biggest difference between hybrid vehicle transmission fault handling and pure fuel AMT transmission and pure electric vehicle is gear selection control. The present invention mainly optimizes this part. If the TCU receives a fault signal during vehicle use, the hybrid transmission fault handling gear control method based on pattern input provided by the present invention is used to handle the fault and control the vehicle to complete the correct gear selection, clutch control and other transmission functions under the fault state.

[0041] The present invention is a hybrid transmission fault processing gear control method based on mode input, the flow chart of which is as follows: Figure 1 As shown, the following steps are included:

[0042] S1, TCU receives the running status signal through the CAN bus and determines whether the vehicle is in a stationary state. If so, execute step S2, if not, execute step S8;

[0043] S2, the TCU receives the gear position signal via the CAN bus and determines whether the vehicle is in the gear shifting process. If so, the process returns to step S1; if not, the process proceeds to step S3;

[0044] S3. The TCU receives the vehicle mode signal via the CAN bus and determines whether the vehicle is in pure electric mode. If so, step S4 is executed; if not, step S5 is executed.

[0045] S4. The TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a pure electric forced return to neutral fault. If so, execute step S6; if not, return to step S1.

[0046] S5. The TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a hybrid forced return to neutral fault. If so, execute step S6; if not, return to step S1.

[0047] S6, TCU sends a command to the transmission via the CAN bus to force the target gear to neutral. The transmission controls the shift actuator and clutch actuator to return to neutral, thus forcing the entire vehicle to return to neutral.

[0048] S7, the TCU receives the instrument and gear position signal feedback via the CAN bus to confirm whether the vehicle is back to neutral. If so, the process returns to step S1; if not, the process returns to step S6;

[0049] S8, the TCU receives the gear position signal via the CAN bus and determines whether the vehicle is in neutral. If so, the process returns to step S1; if not, the process proceeds to step S9;

[0050] S9. The TCU receives a vehicle mode signal via the CAN bus and determines whether the vehicle is in pure electric mode. If so, step S10 is executed; if not, step S11 is executed.

[0051] S10, the TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a pure electric shift prohibition fault. If so, execute step S12; if not, return to step S1;

[0052] S11, the TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a hybrid gear shift prohibition fault. If so, execute step S12; if not, return to step S1;

[0053] S12, the TCU sends a shift prohibition command to the transmission via the CAN bus. The transmission prohibits shifting by controlling the shift actuator and the clutch actuator, forcing the vehicle to maintain the current gear.

[0054] S13. The TCU receives instrument and gear position signal feedback via the CAN bus to confirm whether the vehicle responds to the gear shift prohibition. If not, the process returns to step S12. If so, the vehicle is stopped by braking and waits for maintenance. After the maintenance is completed, the vehicle is shifted into the forward gear and the process returns to step S1 to complete a hybrid transmission fault handling gear control based on the mode input.

[0055] In specific applications, when the input is pure electric mode and the vehicle is not stationary and the gear is not in neutral, if the TCU receives any fault signal from the following: speed fault, low air pressure fault, clutch open fault, CAN bus signal loss fault, and K30 low voltage fault, the program in the TCU will determine that the vehicle has entered a specific fault mode and meets the shift prohibition condition. In this state, the TCU will force the vehicle to maintain the current gear, without shifting up or down, until the vehicle stops. At this time, this state will be exited and the starting gear will be engaged. The vehicle is powered by the electric motor throughout the entire process. If none of the above faults are triggered during this process, the shift prohibition fault state will be promptly exited and the vehicle will respond to normal pure electric gear shifting.

[0056] Also in pure electric mode, when the vehicle is stationary (has been stationary or is currently stationary) and is not in the process of shifting, if the TCU receives any of the following faults: clutch opening fault, CAN bus signal loss fault, K30 low voltage fault and TC1 message (handle message) loss fault, the program in the TCU determines that the vehicle has entered a specific fault mode and meets the forced return to neutral condition. In this state, the TCU forces the current gear to remain in neutral, so that it will not respond to other normal process gear inputs. Only when none of the above faults are triggered will it be determined to exit the forced return to neutral fault mode, and at this time respond to the normal shift process gear.

[0057] When the input is hybrid mode, similar to the pure electric mode mentioned above, the TCU determines whether the vehicle has entered a specific fault mode by receiving vehicle status signals and fault signals. However, hybrid mode's power source primarily comes from the engine, and compared to pure electric mode, it also includes additional modules such as the engine and clutch. Therefore, hybrid mode triggers more fault conditions when entering the two specific fault modes mentioned above.

[0058] Shift prohibited fault mode in hybrid mode: Compared with the pure electric state, several new fault signals have been added, including engine start-stop fault, clutch displacement sensor fault, engine actual speed fault, clutch closing fault and EEC1 message (engine message) loss fault. These faults, together with several faults in pure electric mode, will trigger a specific shift prohibited fault mode in hybrid mode. Its functional utility and exit conditions are the same as those in pure electric mode.

[0059] Forced return to neutral fault mode in hybrid mode: Similarly, several new fault signals are added compared to the pure electric state, which are similar to the prohibited shifting conditions, including engine start-stop fault, engine actual speed fault, clutch closing fault and EEC1 message loss fault. The triggering method, functional utility and exit conditions are also the same as those in the pure electric mode.

[0060] The embodiments described above are merely descriptions of specific implementation methods of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A hybrid transmission fault handling gear control method based on mode input, characterized in that: The following steps are involved: S1. Determine whether the vehicle is in a stationary state. If so, proceed to step S2; if not, proceed to step S8; S2, determining whether the vehicle is in the process of shifting gears, if so, returning to step S1, if not, executing step S3; S3, determine whether the vehicle is in pure electric mode, if so, execute step S4, if not, execute step S5; S4, determining whether the vehicle triggers a pure electric forced return to neutral fault, if so, executing step S6, if not, returning to step S1; S5, determining whether the vehicle triggers a hybrid forced return to neutral fault, if so, executing step S6, if not, returning to step S1; S6, the gearbox returns to neutral gear, and the vehicle is forced to return to neutral gear; S7, confirm whether the vehicle is back to neutral, if so, return to step S1, if not, return to step S6; S8, determine whether the vehicle is in neutral, if so, return to step S1, if not, execute step S9; S9, determining whether the vehicle is in pure electric mode, if so, executing step S10, if not, executing step 11; S10, determining whether the vehicle triggers a pure electric gear shift prohibition fault, if so, executing step S12, if not, returning to step S1; S11, determining whether the vehicle triggers a hybrid gear shift prohibition fault, if so, executing step S12, if not, returning to step S1; S12: The gearbox prohibits the gear shifting operation and forces the vehicle to maintain the current gear; S13, confirm whether the vehicle responds to the prohibition of shifting, if not, return to step S12; If so, the vehicle is stopped by braking and waits for maintenance. After the maintenance is completed, the vehicle is put into forward gear and returns to step S1 to complete a hybrid transmission fault processing gear control based on the mode input.

2. The hybrid transmission fault handling gear control method based on mode input according to claim 1, characterized in that: Step S1 is specifically as follows: the TCU receives the operating status signal through the CAN bus and determines whether the vehicle is in a stationary state. If so, step S2 is executed; if not, step S8 is executed.

3. The hybrid transmission fault handling gear control method based on mode input according to claim 2, characterized in that: Step S2 specifically includes: the TCU receives the gear position signal via the CAN bus and determines whether the vehicle is in the gear shifting process. If so, the process returns to step S1; if not, the process proceeds to step S3; Step S8 is specifically as follows: the TCU receives the gear signal through the CAN bus and determines whether the vehicle is in neutral. If so, the process returns to step S1; if not, the process proceeds to step S9.

4. The hybrid transmission fault handling gear control method based on mode input according to claim 3 is characterized in that: Step S3 is specifically as follows: the TCU receives the vehicle mode signal through the CAN bus and determines whether the vehicle is in pure electric mode. If so, step S4 is executed; if not, step S5 is executed; Step S9 is specifically as follows: the TCU receives the vehicle mode signal through the CAN bus and determines whether the vehicle is in pure electric mode. If so, step S10 is executed; if not, step S11 is executed.

5. The hybrid transmission fault handling gear control method based on mode input according to claim 4, characterized in that: Step S4 is specifically as follows: the TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a pure electric forced return to neutral fault. If so, step S6 is executed; if not, the process returns to step S1. Step S10 is specifically as follows: the TCU receives a fault signal through the CAN bus and determines whether the vehicle triggers a pure electric prohibited shift fault. If so, step S12 is executed; if not, the process returns to step S1.

6. The hybrid transmission fault handling gear control method based on mode input according to claim 5, characterized in that: Step S5 is specifically as follows: the TCU receives a fault signal via the CAN bus and determines whether the vehicle triggers a hybrid forced return to neutral fault. If so, step S6 is executed; if not, the process returns to step S1. Step S11 is specifically as follows: the TCU receives a fault signal through the CAN bus and determines whether the vehicle triggers a hybrid gear shift prohibition fault. If so, step S12 is executed; if not, the process returns to step S1.

7. The hybrid transmission fault handling gear control method based on mode input according to claim 6, characterized in that: Step S6 is specifically as follows: the TCU sends a command to the transmission via the CAN bus to force the target gear to be in neutral, and the transmission controls the shift actuator and the clutch actuator to return to neutral, thereby forcing the entire vehicle to return to neutral. Step S12 is specifically as follows: the TCU sends a shift prohibition instruction to the transmission through the CAN bus, and the transmission prohibits the shifting operation by controlling the shift actuator and the clutch actuator, forcing the entire vehicle to maintain the current gear.

8. The hybrid transmission fault handling gear control method based on mode input according to claim 7, characterized in that: Step S7 specifically includes: the TCU receives the instrument and gear position signal feedback via the CAN bus to confirm whether the vehicle is in neutral gear. If so, the process returns to step S1; if not, the process returns to step S6; Step S13 specifically includes: the TCU receives the instrument and gear position signal feedback via the CAN bus, confirms whether the vehicle responds to the gear shift prohibition, and if not, returns to step S12; If so, the vehicle is stopped by braking and waits for maintenance. After the maintenance is completed, the vehicle is put into forward gear and returns to step S1 to complete a hybrid transmission fault processing gear control based on the mode input.

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