Gearbox gear control method during power-on and power-off of pure electric commercial vehicle

Abstract

This invention provides a method for controlling the gearbox gear position during power-on and power-off processes in a pure electric commercial vehicle, relating to the field of new energy vehicle technology. The method comprises the following steps: S1, the driver rotates the cab key switch to the "on" position, connecting the vehicle's circuitry and achieving low-voltage power-on, at which point the vehicle enters a standby state; S2, the system waits for the driver to initiate a high-voltage power-on request via the HCU. When the HCU receives the request, step S3 is executed; S3, after performing the high-voltage power-on pre-operation, the vehicle's high-voltage power-on operation is performed; S4, when the driver wants to de-energize, a high-voltage power-off request is initiated. When the HCU receives the request, step S5 is executed; S5, after performing the high-voltage power-off pre-operation, the vehicle's high-voltage power-off operation is performed; S6, the driver rotates the cab key switch to the "off" position, and the system achieves low-voltage power-off. The beneficial effects include: reducing time delays, reducing component wear and tear, extending component lifespan, and reducing the probability of failures during gear shifting.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, specifically to a method for controlling the gear position of a transmission during the power-on and power-off process of a pure electric commercial vehicle. Background Technology

[0002] The high-voltage power-on / off process is the most fundamental control procedure for pure electric commercial vehicles, directly determining the vehicle's start-up response speed, driving smoothness, and overall lifespan. To meet mandatory safety requirements, traditional pure electric commercial vehicle power-on / off control schemes mandate that the transmission perform a physical return to neutral before power-on / off. This means that the vehicle controller (HCU) sends a return-to-neutral command to the transmission controller (TCU). The TCU then drives physical actuators such as the shift motor, solenoid valve, shift fork, and gear engagement mechanism to shift the transmission's actual gear to physical neutral. After the gear position sensor detects and confirms the neutral position, the TCU sends a true neutral signal back to the HCU. Only after receiving the true neutral signal does the HCU allow the high-voltage power-on or high-voltage power-off operation to be performed.

[0003] However, the high-voltage power-on / off process of this vehicle has the following problems: (1) Time delay: The physical shift mechanism takes a certain amount of time to perform neutral shift, which slows down the overall process of powering on or off the vehicle and affects the user experience, especially the feeling when starting up; (2) Component wear: Frequent and unnecessary physical gear shifting operations will increase the mechanical wear of the gear shifting actuator and reduce its lifespan; (3) Energy loss: Physical gear shifting requires electrical energy; (4) Complex logic: When the power is turned on again after being turned off, the TCU needs to shift back from neutral to the previous driving gear (D / R), which is complex and increases the probability of failure. Summary of the Invention

[0004] The main objective of this invention is to provide a method for controlling the gear position of a transmission during the power-on and power-off process of a pure electric commercial vehicle, thereby solving the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for controlling the gear position of a transmission during the power-on and power-off process of a pure electric commercial vehicle, wherein the electric commercial vehicle includes: a vehicle controller (HCU) and a transmission controller (TCU); the control method includes the following steps: S1. When the driver turns the cab key switch to the "on" position, the entire vehicle's circuit is connected. At this time, the HCU and TCU complete initialization and system self-test, realize low-voltage power-on, and enter the standby state. S2. Wait for the HCU driver to initiate a high-voltage power-on request. When the HCU receives the high-voltage power-on request, execute step S3. Otherwise, remain in standby mode and do not perform other operations. S3. After performing the high-voltage power-on pre-operation, perform the vehicle high-voltage power-on operation. The pre-operation of high-voltage power-on includes: sending a virtual neutral signal, switching between dual-state permission control modes, and judging the conditions for high-voltage power-on. S4. When the driver wants to cut off the high voltage, a high voltage cut-off request is initiated. When the HCU receives the high voltage cut-off request, step S5 is executed. S5. After performing the high-voltage power-off pre-operation, perform the vehicle high-voltage power-off operation; S6. When the driver rotates the cab key switch to the off position, the low-voltage circuit of the whole vehicle is disconnected, and the system achieves low-voltage power-off.

[0006] Furthermore, the high-voltage power-on request is initiated as follows: with the key switch in the "on" position, the gear lever in the "N" position, and the driver pressing the brake pedal.

[0007] Furthermore, the detailed process of sending the virtual neutral signal is as follows: The TCU obtains vehicle speed, brake light switch signal, N gear signal and vehicle fault status information from the HCU, and determines whether all power-on virtual neutral enable conditions are met based on the obtained information; when all power-on virtual enable conditions are met, the TCU keeps the target gear of the transmission unchanged, sends the virtual neutral signal to the HCU, and performs dual-state permission control mode switching. The virtual neutral enable conditions include: The vehicle's real-time speed is 0; The brake light switch signal is valid. The confirmation method for whether the signal is valid is: the HCU collects the brake light switch signal in real time, and when the brake light switch signal shows that the brake light switch is in the closed state, the brake light switch signal is determined to be valid. The gear lever is in the neutral (N) position.

[0008] Furthermore, the dual-state access control mode includes: a normal access domain and a virtual gap access domain; The normal permission domain takes effect when the virtual neutral gear is not triggered during normal driving or standby. At this time, the HCU has the highest control authority of the whole vehicle. The HCU can issue all vehicle scheduling commands to the TCU. The TCU obeys the vehicle scheduling commands of the HCU by default. The virtual neutral permission domain takes effect after the HCU recognizes a high-voltage power-on or high-voltage power-off request and the TCU meets the virtual neutral enable conditions and outputs a virtual neutral signal. At this time, the HCU loses the authority to send any shift commands to the TCU, and the TCU autonomously manages the gear position status, torque limit and local safety logic of the transmission. The detailed process of switching between dual-state access control modes is as follows: The HCU recognizes the high-voltage power-on request and the TCU meets the virtual neutral enable conditions for power-on and outputs a virtual neutral signal. After receiving the virtual neutral signal, the HCU switches the dual-state permission control mode from the normal permission domain to the virtual neutral permission domain. After the switch is completed, the HCU performs a high-voltage power-on condition judgment.

[0009] Furthermore, the process of determining the high-voltage power-on conditions is as follows: the HCU determines the high-voltage power-on conditions, and when all the high-voltage power-on conditions are met, it performs the high-voltage power-on operation. When a fault that prevents high-voltage power-on is detected, the dual-state permission control mode switches from the virtual neutral permission domain back to the normal permission domain. High-voltage power-on conditions include: Keep the key switch in the ON position; MCU initialization complete; BMS initialization complete; The vehicle's real-time speed is 0; Brake light switch signal is valid; The gear lever is in neutral (N). The vehicle has no faults that prohibit high-voltage power-on. DC charging is not connected; AC charging is not connected; The accelerator pedal was not pressed. TCU virtual neutral signal has been received.

[0010] Furthermore, during the high-voltage power-on operation of the vehicle, upon completion of the high-voltage power-on, a dual-state permission control mode switch is performed, switching from the virtual neutral permission domain to the normal permission domain.

[0011] Furthermore, the method for initiating a high-voltage power-down request is as follows: With the vehicle stationary and at a speed of 0, the driver shifts the gear to neutral (N).

[0012] Furthermore, the high-voltage power-off pre-operation includes: sending a virtual neutral signal, switching between dual-state permission control modes, and determining the high-voltage power-off conditions.

[0013] Furthermore, during the high-voltage power-off pre-operation, the dual-state permission control mode switching is from the virtual neutral permission domain back to the normal permission domain; The conditions for high-voltage energization include: Keep the key switch in the ON position; The vehicle's real-time speed is 0; Brake light switch signal is valid; The gear lever is in neutral (N). DC charging is not connected; AC charging is not connected; The accelerator pedal was not pressed. TCU virtual neutral signal has been received.

[0014] Furthermore, during the high-voltage power-off operation of the vehicle, upon completion of the high-voltage power-off, a dual-state permission control mode switch is performed, switching from the virtual neutral permission domain to the normal permission domain.

[0015] Beneficial effects: (1) The gearbox control scheme in the power-on and power-off process of this application can realize the power-on and power-off of the gearbox in non-neutral mode. That is, during the power-on and power-off process, the whole vehicle does not need to adjust the gearbox to neutral, which can reduce time delay, reduce component wear, reduce its lifespan and reduce the probability of failure during gear shifting. (2) The introduction of dual-state access control mode can fundamentally avoid the problems of HCU sending gear control commands by mistake, TCU misadjusting gears, causing power failure or even potential hazards during power-on and power-off processes. (3) Dual-state access control mode takes into account the fault situation and further increases security. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a flowchart of the steps of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] It should be understood that the illustrative drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may be implemented out of order, and steps without logical contextual relationships may be reversed or performed simultaneously. Furthermore, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0019] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] like Figure 1 As shown in the figure, this embodiment provides a method for controlling the gear position of the transmission during the power-on and power-off process of a pure electric commercial vehicle. Before introducing the control method, the pure electric commercial vehicle to which the control method is applied is first introduced. The pure electric commercial vehicle includes a vehicle controller (HCU), a transmission controller (TCU), a motor controller (MCU), and other components such as a motor. The transmission control unit (TCU) is a transmission device that can automatically shift gears based on vehicle speed and engine speed. The vehicle controller and the transmission controller communicate via CAN. The vehicle controller (HCU) sends control commands to the transmission controller and receives feedback signals from the transmission controller.

[0021] The control methods are described below, such as... Figure 1 As shown, a method for controlling the gear position of a transmission during the power-on and power-off process of a pure electric commercial vehicle includes the following steps: S1. When the driver turns the cab key switch to the "on" position, the vehicle's circuit is connected. At this time, the vehicle controller HCU and the transmission controller TCU complete initialization and system self-test, realize low-voltage power-on, and enter the standby state. The vehicle also includes: motor controller MCU, battery management system BMS, CAN communication network, sensor module, and actuator module. The specific process for this step is as follows: When the driver switches the vehicle key switch from the OFF position to the ON position, the vehicle's low-voltage power system is turned on. The low-voltage battery supplies power to the vehicle controller HCU, transmission controller TCU, motor controller MCU, battery management system BMS, CAN communication network, sensor module, and actuator module. Each controller sequentially completes low-voltage wake-up, hardware initialization, port configuration, software version verification, and internal register initialization operations. After initialization, each controller performs a system self-test. The HCU self-tests the high-voltage circuit status, CAN communication status, brake light switch signal validity, vehicle speed signal validity, and insulation detection status; the TCU self-tests the gear position sensor status, shift actuator status, power supply voltage, communication status, and internal fault codes; the MCU self-tests the drive motor status, power module status, temperature status, and fault codes; and the BMS self-tests the power battery voltage, current, temperature, insulation status, high-voltage relay status, and fault codes. After all controllers have no faults in their self-tests, they send a normal status signal back to the HCU via the CAN bus, and low-voltage power-on is complete. If any controller has a fault in its self-test, it immediately reports a fault code and prevents the subsequent power-on / off process from proceeding.

[0022] S2. Wait for the HCU driver to initiate a high-voltage power-on request. When the HCU receives the high-voltage power-on request, execute step S3. Otherwise, remain in standby mode and do not perform other operations. The high-voltage power-on request is initiated as follows: with the key switch in the "on" position, the gear lever in the "N" position, and the driver pressing the brake pedal; "N" is the parking gear. S3. After performing the high-voltage power-on pre-operation, perform the vehicle high-voltage power-on operation. The pre-operation of high-voltage power-on includes: sending a virtual neutral signal, switching between dual-state permission control modes, and judging the conditions for high-voltage power-on.

[0023] The detailed process of sending the virtual neutral signal is as follows: The TCU obtains vehicle speed, brake light switch signal, N gear signal and vehicle fault status information from the HCU via the CAN bus. Based on the obtained information, it determines whether all the power-on virtual neutral enable conditions are met. When all the power-on virtual enable conditions are met, the TCU keeps the transmission target gear unchanged and sends the virtual neutral signal to the HCU. Here, the target gear refers to the transmission's physical gear when it was last powered off. The virtual neutral enable conditions include: The vehicle's real-time speed is 0; The brake light switch signal is valid. The validity of this signal is confirmed by the HCU acquiring the brake light switch signal in real time. When the brake light switch signal shows that the brake light switch is in the closed state, the brake light switch signal is determined to be valid. The gear lever is in the neutral (N) position.

[0024] After receiving the virtual neutral signal, the HCU performs a dual-state access control mode switch; the dual-state access control mode includes: normal access control domain and virtual neutral access control domain; The normal permission domain takes effect when the virtual neutral gear is not triggered during normal driving or standby. At this time, the HCU has the highest control authority of the whole vehicle. The HCU can issue all vehicle scheduling commands to the TCU. The TCU obeys the vehicle scheduling commands of the HCU by default. The virtual neutral permission domain takes effect after the HCU recognizes a high-voltage power-on or high-voltage power-off request and the TCU meets the virtual neutral enable conditions and outputs a virtual neutral signal. At this time, the HCU actively reduces its authority and loses the authority to send any shift commands to the TCU. The TCU then autonomously manages the gear position status, torque limit, and local safety logic of the transmission. The system prioritizes hardware-level safety protection, fault gear limit, forced physical return of the transmission to neutral, and high-voltage circuit safety protection strategies, abandoning the virtual neutral gear holding control logic, with the high-voltage safety of the whole vehicle and the mechanical gear safety as the primary constraints; The transmission status information includes: TCU gear status, fault status, hardware status, and heartbeat messages; The detailed process of switching between dual-state access control modes before the vehicle is powered on is as follows: The HCU recognizes the high-voltage power-on request and the TCU meets the power-on virtual neutral enable conditions and outputs a virtual neutral signal. After receiving the virtual neutral signal, the HCU switches the dual-state permission control mode from the normal permission domain to the virtual neutral permission domain.

[0025] After the dual-state access control mode is switched, the HCU performs a high-voltage power-on condition judgment. When all high-voltage power-on conditions are met, the high-voltage power-on operation is executed. When a fault that prohibits high-voltage power-on is detected, the dual-state access control mode switches from the virtual neutral access domain back to the normal access domain. High-voltage power-on conditions include: Keep the key switch in the ON position; MCU initialization complete; BMS initialization complete; The vehicle's real-time speed is 0; Brake light switch signal is valid; The gear lever is in neutral (N). There are no faults that prohibit high-voltage power-on in the vehicle; faults that prohibit high-voltage power-on can be divided into: high-voltage battery system faults, gear position and vehicle safety condition faults, gearbox and TCU related faults, and high-voltage accessories and power system faults. DC charging is not connected; AC charging is not connected; The accelerator pedal was not pressed. TCU virtual neutral signal has been received.

[0026] The high-voltage power-on process includes: the HCU sends a high-voltage power-on request command to the BMS; after receiving the power-on command and completing the secondary self-test and insulation re-test of the power battery, the BMS closes the pre-charge relay to execute the high-voltage pre-charge stage; the BMS monitors the bus voltage and determines that the pre-charge is complete; the BMS closes the main positive / main negative high-voltage relay to establish a complete high-voltage circuit; at this time, the BMS feeds back the high-voltage power-on completion status to the HCU; the HCU synchronizes the vehicle status and sends a ready command; the vehicle enters READY mode; at the same time, the dual-state permission control mode switches from the virtual neutral permission domain back to the normal permission domain. At this point, the vehicle has completed the entire power-on process, including both low-voltage and high-voltage power-on.

[0027] After power-on, the dual-state permission control mode switches from the virtual neutral permission domain to the normal permission domain. At this time, the TCU exits the virtual neutral state, resumes reporting the actual physical gear position of the transmission, and the TCU responds normally to the HCU torque request. Since the vehicle is now in READY mode, the driver can start the vehicle by following normal driving operations. Specifically, the driver presses the brake pedal, shifts the gear lever from N to D / R, slowly releases the brake pedal, and lightly presses the accelerator pedal to move forward or reverse.

[0028] It should be noted that the control operation during the power-on process of this application ends upon completion of power-on. However, since the start-up phase usually begins after power-on, a brief description of the common vehicle start-up process is provided here to make the technical solution of this application more complete and to demonstrate its advantages. For example, in a conventional power-on solution, after entering READY mode, the TCU still needs to adjust the actual physical gear position of the transmission before the driver can start the vehicle according to normal driving operations. In this technical solution, the transmission gear position does not need to be adjusted.

[0029] S4. When the driver wants to cut off the high voltage, a high voltage cut-off request is initiated. When the HCU receives the high voltage cut-off request, step S5 is executed. The high-voltage power-down request is initiated as follows: With the vehicle stationary and at a speed of 0, the driver shifts the gear to neutral (N).

[0030] S5. After performing the high-voltage power-off pre-operation, execute the vehicle high-voltage power-off operation; The pre-power-off operation includes: sending a virtual neutral signal, switching between dual-state access control modes, and determining the conditions for power-off.

[0031] The detailed process of sending a virtual neutral signal is as follows: The TCU obtains vehicle speed, brake light switch signal, N gear signal and vehicle fault status information from the HCU via the CAN bus. Based on the information obtained, it determines whether all the power-down virtual neutral enable conditions are met. When all the power-down virtual enable conditions are met, the TCU keeps the transmission target gear unchanged and sends a virtual neutral signal to the HCU. The virtual neutral enable conditions after power-down include: The vehicle's real-time speed is 0; Brake light switch signal is valid; The gear lever is in the neutral (N) position.

[0032] The detailed process of switching between dual-state access control modes before the vehicle's high-voltage power is cut off is as follows: The HCU recognizes the high-voltage power-off request and the TCU meets the virtual neutral enable conditions for power-off and outputs a virtual neutral signal. After receiving the virtual neutral signal, the HCU switches the dual-state permission control mode from the normal permission domain to the virtual neutral permission domain.

[0033] After the dual-state access control mode is switched, the HCU performs a high-voltage power-down condition judgment. When all high-voltage power-down conditions are met, the high-voltage power-down operation is executed. The conditions for high-voltage energization include: Keep the key switch in the ON position; The vehicle's real-time speed is 0; Brake light switch signal is valid; The gear lever is in neutral (N). DC charging is not connected; AC charging is not connected; The accelerator pedal was not pressed. TCU virtual neutral signal has been received.

[0034] The high-voltage power-off process includes: the HCU sends a high-voltage power-off request command to the BMS; after receiving the power-off command, the BMS completes the self-check of the power battery's operating condition and the re-check of the high-voltage circuit status, cuts off the power output on the high-voltage load side and shuts down the working status of each high-voltage accessory; the BMS disconnects the main positive high-voltage relay and maintains the bus voltage buffer to fall back; after the bus voltage decays to the safe threshold, the BMS disconnects the main negative high-voltage relay, completely cutting off the high-voltage circuit of the entire vehicle; at this time, the BMS feeds back the high-voltage power-off completion status to the HCU; the HCU synchronizes the sleep commands of each controller in the vehicle and locks the power output status; the entire vehicle exits the READY mode; at this time, the high-voltage power-off of the entire vehicle is completed, and it returns to the standby mode; at the same time, the dual-state permission control mode switches from the virtual neutral permission domain to the normal permission domain. During the high-voltage power-down process, the vehicle did not shift the actual physical gear of the transmission back to neutral, thus achieving high-voltage power-down without shifting the transmission gear.

[0035] S6. When the driver rotates the cab key switch to the off position, the low-voltage circuit of the whole vehicle is disconnected and the system is powered off. At this point, the vehicle has completed the full power-down process, which includes both high-voltage and low-voltage power-down.

[0036] It should be noted that the transmission control method during the power-on and power-off processes included in the technical solution of this application includes transmission control during the power-on and power-off processes. Furthermore, the transmission control steps during the power-on and power-off processes can be implemented independently. That is, during a single driving session, the driver may not execute the complete power-on / off control process every time, but only a portion of it. For example, after parking, the driver may only execute the high-voltage power-off operation, leaving the vehicle system in standby mode, and then execute the high-voltage power-on operation, without needing to complete the low-voltage power-off operation after the high-voltage power-off operation and then re-execute the power-on process. It should also be noted that low-voltage power-on is a prerequisite for high-voltage power-on, and high-voltage power-off is a prerequisite for high-voltage power-off.

[0037] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for controlling the gear position of a transmission during the power-on and power-off process of a pure electric commercial vehicle, the electric commercial vehicle comprising: The vehicle control unit (HCU) and the transmission control unit (TCU) are characterized by a control method comprising the following steps: S1. When the driver turns the cab key switch to the "on" position, the entire vehicle's circuit is connected. At this time, the HCU and TCU complete initialization and system self-test, realize low-voltage power-on, and enter the standby state. S2. Wait for the HCU driver to initiate a high-voltage power-on request. When the HCU receives the high-voltage power-on request, execute step S3. Otherwise, remain in standby mode and do not perform other operations. S3. After performing the high-voltage power-on pre-operation, perform the vehicle high-voltage power-on operation. The pre-operation of high-voltage power-on includes: sending a virtual neutral signal, switching between dual-state permission control modes, and judging the conditions for high-voltage power-on. S4. When the driver wants to cut off the high voltage, a high voltage cut-off request is initiated. When the HCU receives the high voltage cut-off request, step S5 is executed. S5. After performing the high-voltage power-off pre-operation, perform the vehicle high-voltage power-off operation; S6. When the driver rotates the cab key switch to the off position, the low-voltage circuit of the whole vehicle is disconnected, and the system achieves low-voltage power-off.

2. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 1, characterized in that, The high-voltage power-on request is initiated as follows: with the key switch in the "on" position, the gear lever in the "N" position, and the driver pressing the brake pedal.

3. The method for controlling the gearbox gear position during power-on and power-off processes of a pure electric commercial vehicle according to claim 1, characterized in that, The detailed process of sending the virtual neutral signal is as follows: The TCU obtains vehicle speed, brake light switch signal, N gear signal and vehicle fault status information from the HCU. Based on the information obtained, it determines whether all power-on virtual neutral enable conditions are met. When all power-on virtual enable conditions are met, the TCU keeps the target gear of the transmission unchanged, sends the virtual neutral signal to the HCU, and performs dual-state permission control mode switching. The virtual neutral enable conditions include: The vehicle's real-time speed is 0; The brake light switch signal is valid. The confirmation method for whether the signal is valid is: the HCU collects the brake light switch signal in real time, and when the brake light switch signal shows that the brake light switch is in the closed state, the brake light switch signal is determined to be valid. The gear lever is in the neutral (N) position.

4. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 3, characterized in that, Dual-state access control mode includes: normal access domain and virtual gap access domain; The normal permission domain takes effect when the virtual neutral gear is not triggered during normal driving or standby. At this time, the HCU has the highest control authority of the whole vehicle. The HCU can issue all vehicle scheduling commands to the TCU. The TCU obeys the vehicle scheduling commands of the HCU by default. The virtual neutral permission domain takes effect after the HCU recognizes a high-voltage power-on or high-voltage power-off request and the TCU meets the virtual neutral enable conditions and outputs a virtual neutral signal. At this time, the HCU loses the authority to send any shift commands to the TCU, and the TCU autonomously manages the gear position status, torque limit and local safety logic of the transmission. The detailed process of switching between dual-state access control modes is as follows: The HCU recognizes the high-voltage power-on request and the TCU meets the virtual neutral enable conditions for power-on and outputs a virtual neutral signal. After receiving the virtual neutral signal, the HCU switches the dual-state permission control mode from the normal permission domain to the virtual neutral permission domain. After the switch is completed, the HCU performs a high-voltage power-on condition judgment.

5. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 4, characterized in that, The process of determining the high-voltage power-on conditions is as follows: The HCU performs a high-voltage power-on condition determination. When all high-voltage power-on conditions are met, the high-voltage power-on operation is executed. When a fault that prevents high-voltage power-on is detected, the dual-state permission control mode switches from the virtual neutral permission domain back to the normal permission domain. High-voltage power-on conditions include: Keep the key switch in the ON position; MCU initialization complete; BMS initialization complete; The vehicle's real-time speed is 0; Brake light switch signal is valid; The gear lever is in neutral (N). The vehicle has no faults that prohibit high-voltage power-on. DC charging is not connected; AC charging is not connected; The accelerator pedal was not pressed. TCU virtual neutral signal has been received.

6. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 4, characterized in that, During the high-voltage power-on operation of the vehicle, when the high-voltage power-on is completed, a dual-state permission control mode switch is performed, switching from the virtual neutral permission domain to the normal permission domain.

7. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 1, characterized in that, The high-voltage power-down request is initiated as follows: With the vehicle stationary and at a speed of 0, the driver shifts the gear to neutral (N).

8. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 5, characterized in that, The pre-power-off operation includes: sending a virtual neutral signal, switching between dual-state access control modes, and determining the conditions for power-off.

9. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 4, characterized in that, During the high-voltage power-off pre-operation, the dual-state permission control mode switching is from the virtual neutral permission domain back to the normal permission domain; The conditions for high-voltage energization include: Keep the key switch in the ON position; The vehicle's real-time speed is 0; Brake light switch signal is valid; The gear lever is in neutral (N). DC charging is not connected; AC charging is not connected; The accelerator pedal was not pressed. TCU virtual neutral signal has been received.

10. The method for controlling the gearbox gear position during power-on and power-off of a pure electric commercial vehicle according to claim 9, characterized in that, During the high-voltage power-off operation of the vehicle, a dual-state permission control mode switch is performed once the high-voltage power-off is completed, switching from the virtual neutral permission domain to the normal permission domain.

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