New energy vehicle network fault diagnosis measure method

Abstract

The invention discloses a new energy whole vehicle network fault diagnosis measure method which comprises an SCU gear shifting controller control unit, gear request (P, R, N and D) signals are sent to a power domain control and ABS anti-lock braking system through a CAN network by recognizing the gear shifting operation of a driver, and the system calculates the vehicle speed for collecting the wheel speed signals of four wheels; and a vehicle speed signal is sent to a power domain controller and an ESP vehicle body electronic stabilization system through a CAN network. The invention provides a brand new fault diagnosis response measure method for the whole vehicle CAN bus BUS OFF fault aiming at a new energy whole vehicle power domain controller and a distributed power assembly controller. When the vehicle is in a driving state, the whole vehicle can still be ensured to run normally in the current state when the CAN bus BUS off occurs, but the driving function of quitting the response needs to be analyzed on the specific scene working condition of a sample vehicle so as to ensure the running safety of the vehicle, and when the CAN bus BUS OFF fault is recovered, the current fault response is eliminated, and the running robustness of the vehicle is ensured when the vehicle has short-time intermittent BUS off.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle network fault diagnosis, and in particular to a new energy vehicle network fault diagnosis measure method. Background Art

[0002] With the rapid development of new energy vehicle technology, the market share of pure electric vehicles has increased year by year. In response to the diversity of customer needs, pure electric vehicles have more and more specific functions, and the number of controllers has gradually increased. However, this has also brought about various network communication failures in the whole vehicle due to environmental durability, parts, wiring harnesses and plug-in quality. There are more and more problems of serious network failures in new energy vehicles leading to functional failure of the whole vehicle or even power loss, especially CAN bus BUS off. In a non-domain control network architecture, this problem is caused by the loss of communication between controllers, resulting in the need to exit the driving mode, exit the charging mode and other response measures in order to ensure the safety of the vehicle and personnel. The robustness and availability of the vehicle are greatly reduced. As pure electric vehicles increase the power domain control unit, a set of diagnostic response methods based on different scenarios can be formulated for the CAN bus BUS off response measures, reducing the serious response measures such as exiting the driving mode and prohibiting charging, and further improving the diagnostic response measures for vehicle use robustness.

[0003] At present, new energy vehicles have CAN bus BUS off failures, usually because the controller cannot receive and send signals normally. In order to ensure the safety of the vehicle and personnel, the power output will be cut off when driving, and the charging will be terminated when charging. Although this method can ensure the safety of the vehicle and personnel to a certain extent, the robustness and availability of the vehicle will be greatly reduced. Based on this, diagnostic measures for distributed powertrain controllers and domain controllers under different network failure scenarios and working conditions are proposed respectively. Summary of the invention

[0004] The technical problem to be solved by the present invention is to propose a diagnostic measure method for detecting network faults in a power domain controller and a distributed powertrain controller of a new energy vehicle.

[0005] The present invention aims at the current situation that when a new energy vehicle controller diagnoses that the vehicle CAN bus BUS off (Note: CAN bus BUS off is a more serious network failure), due to communication interruption, the existing method usually cuts off the power output under severe response measures at high voltage without identifying and executing response measures for the current scenario working condition.

[0006] The network fault diagnosis method of the present invention is a control method for ensuring that the vehicle can maintain a normal driving state and needs to execute different response measures in combination with scene conditions. It solves the problem that the domain controller of the new energy vehicle can not only ensure the continuous driving of the sample vehicle but also execute protection response measures for the whole vehicle in different scenarios when the whole vehicle CAN bus BUSoff occurs. Thereby improving the advantages and robustness of the domain controller. For the new energy vehicle divided controller, when the whole vehicle CAN bus BUS off is diagnosed, different response measures are adopted for different scenarios in combination with fault confirmation and fault recovery, which ensures the safety of the vehicle and personnel and maximizes the robustness of the vehicle.

[0007] In order to achieve the above objectives, a new energy vehicle network fault diagnosis method is provided, including: The SCU shift controller control unit sends the gear request (P, R, N, D) signal to the power domain control through the CAN network by identifying the driver's shift operation; ABS anti-lock braking system, which collects four-wheel speed signals to calculate vehicle speed and sends the vehicle speed signal to the power domain controller through the CAN network; ESP electronic stability system, which sends an activation signal to the power domain controller when activated; The NBS line controller system sends the electric brake energy recovery demand signal to the power domain controller through the CAN network; The SWM combination switch control unit sends the cruise control switch request signal from the driver's cruise control button operation to the power domain controller via the CAN network; The IC instrument display control unit and PEPS are a one-button start system. The power domain controller integrates the traditional VCU vehicle control unit, MCU motor controller, BMS battery management system, DCDC DC-to-DC control module, and OBC on-board charger control unit functions, and mainly controls the vehicle's powertrain.

[0008] According to the new energy vehicle network fault diagnosis measure method, the power domain controller determines that the vehicle is in a drivable mode. In this mode, the vehicle is detected to see whether the CAN bus BUS off fault is confirmed. If so, the IC instrument prompt lights up in the next step. Because the ABS vehicle speed signal cannot be transmitted to the power domain controller, the power domain controller no longer uses the ABS vehicle speed to calculate the vehicle speed, and uses the motor speed to calculate the vehicle speed (u=0.377nr / igi0).

[0009] According to the new energy vehicle network fault diagnosis measures, determine whether the vehicle is in cruise control before the CAN BUS off fault is confirmed. If so, exit the cruise control. Here, due to the interruption of communication with the chassis brake system controller, the system cannot guarantee the stability of the cruise control function and needs to exit the cruise control.

[0010] According to the new energy vehicle network fault diagnosis measures and methods, it is determined whether the driver wants to enter the cruise control by the switch key before the CAN BUS off fault is confirmed. If so, entering the cruise control is prohibited. The switch key here is defined as the combination switch controller sent to the power domain controller through CAN communication. If the power domain controller directly collects hard wires, the cruise control can be entered.

[0011] According to the new energy vehicle network fault diagnosis measures, it is determined whether the vehicle is in the braking energy recovery process before the CAN BUS off fault is confirmed. If so, the braking energy recovery torque request is exited. Here, because the communication between the power domain controller and the braking system is interrupted, it is impossible to ensure that the vehicle's braking is unstable, so it is necessary to exit from a safety perspective.

[0012] According to the new energy vehicle network fault diagnosis measures and methods, otherwise it is further determined whether the vehicle speed is ≤3kph before the CAN BUS off fault is confirmed. If so, the domain control executes the associated vehicle speed to return to N gear control. Here, due to the loss of communication with the gear controller, the current gear can be maintained at high speeds, and it is necessary to exit the driving gear at low speeds to ensure safety.

[0013] According to the new energy vehicle network fault diagnosis measures, it is further determined whether the current bus BUS off fault is restored. If so, the vehicle response measures are cleared and the sample vehicle is still in a drivable mode. According to network specifications, when the CAN bus BUS off occurs, each controller needs to perform five fast recoveries and multiple slow recoveries until the network communication returns to normal.

[0014] The above solution has at least one of the following beneficial effects: 1. The key point and protection point of the present invention is to propose a new fault diagnosis response measure method for the vehicle CAN bus BUS OFF fault. Different diagnostic measures are given for the power domain controller and distributed powertrain controller of the new energy vehicle respectively. By identifying different scene conditions and exiting the corresponding driving function to ensure the safety of vehicle operation, the current fault response is cleared when the fault is restored to maintain the robustness of the vehicle.

[0015] 2. The present invention proposes a new fault diagnosis response measure method for the CAN bus BUS OFF fault of the whole vehicle for the power domain controller and the distributed powertrain controller of the new energy vehicle. When the vehicle is in a drivable state, the whole vehicle can still ensure normal driving in the current state when the CAN bus BUS off occurs, but it is necessary to analyze the driving function of the specific scenario working condition of the sample vehicle to exit the response to ensure the safety of vehicle operation. When the CAN bus BUS OFF fault is restored, the current fault response is cleared to ensure the robustness of vehicle operation when the vehicle is short-term intermittent BUS off. Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described below in conjunction with the accompanying drawings and embodiments; Figure 1 This is the vehicle network topology diagram of the power domain controller of the present invention; Figure 2 This is the vehicle network topology diagram of the distributed powertrain controller of the present invention; Figure 3 It is a flow chart of the CAN bus BUS off diagnosis response method in the driving mode of the power domain controller of the present invention; Figure 4 This is a flow chart of the CAN bus BUS off diagnostic response method in the power domain controller charging mode of the present invention; Figure 5 This is a flow chart of the CAN bus BUS off diagnostic response method of the distributed powertrain controller of the present invention. DETAILED DESCRIPTION

[0017] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0018] Embodiment 1 Reference Figures 1 to 5 , the new energy vehicle network fault diagnosis method according to the embodiment of the present invention comprises: The SCU shift controller control unit sends the gear request (P, R, N, D) signal to the power domain control through the CAN network by identifying the driver's shift operation; ABS anti-lock braking system, which collects four-wheel speed signals to calculate vehicle speed and sends the vehicle speed signal to the power domain controller through the CAN network; ESP electronic stability system, which sends an activation signal to the power domain controller when activated; The NBS line controller system sends the electric brake energy recovery demand signal to the power domain controller through the CAN network; The SWM combination switch control unit sends the cruise control switch request signal from the driver's cruise control button operation to the power domain controller via the CAN network; The IC instrument display control unit and PEPS are a one-button start system. The power domain controller integrates the traditional VCU vehicle control unit, MCU motor controller, BMS battery management system, DCDC DC-to-DC control module, and OBC on-board charger control unit functions, and mainly controls the vehicle's powertrain.

[0019] First, the power domain controller determines that the vehicle is in a drivable mode. In this mode, it detects whether the vehicle confirms that the CAN bus is off. If so, the IC instrument prompts the light to turn on. Because the ABS speed signal cannot be transmitted to the power domain controller, the power domain controller no longer uses the ABS speed to calculate the speed, but uses the motor speed to calculate the speed (u=0.377nr / igi0). Then determine whether the vehicle is in cruise control before the CAN BUS off fault is confirmed. If so, exit cruise control. Here, because the communication with the chassis brake system controller is interrupted, the system cannot guarantee the stability of the cruise control function and needs to exit cruise control. Otherwise, determine whether the driver wants to enter the cruise control by pressing the on / off key before the CAN BUS off fault is confirmed. If so, the cruise control is prohibited. The on / off key is defined as the combination switch controller sending the CAN communication to the power domain controller. If the power domain controller directly collects the data by hard wire, the cruise control can be entered. Otherwise, it is determined whether the vehicle is in the braking energy recovery process before the CAN BUS off fault is confirmed. If so, the braking energy recovery torque request is exited. Since the communication between the power domain controller and the braking system is interrupted, it is impossible to ensure that the vehicle brakes are unstable, so it is necessary to exit from a safety perspective; Otherwise, it is further determined whether the vehicle speed before the CAN BUS off fault is confirmed is ≤3kph. If so, the domain control executes the control of returning the associated vehicle speed to N gear. Since the communication with the gear controller is lost here, the current gear can be maintained at high speeds, but the driving gear needs to be exited at low speeds to ensure safety. Further determine whether the current bus BUS off fault has been restored. If so, clear the vehicle response measures and the sample vehicle is still in the drivable mode. According to the network specification, when the CAN bus BUS off occurs, each controller needs to perform five fast recoveries and multiple slow recoveries until the network communication returns to normal.

[0020] The key point and protection point of this invention is to propose a new fault diagnosis response measure method for the vehicle CAN bus BUS OFF fault. Different diagnostic measures are given for the power domain controller and distributed powertrain controller of new energy vehicles respectively. By identifying different scene conditions and exiting the corresponding driving function to ensure the safety of vehicle operation, the current fault response is cleared when the fault is restored to maintain the robustness of the vehicle.

[0021] The present invention proposes a new fault diagnosis response measure method for the vehicle CAN bus BUS OFF fault for the power domain controller and the distributed powertrain controller of the new energy vehicle. When the vehicle is in a drivable state, the vehicle can still ensure normal driving in the current state when the CAN bus BUS off occurs, but it is necessary to analyze the driving function of the specific scenario working condition of the sample vehicle to exit the response to ensure the safety of vehicle operation. When the CAN bus BUS OFF fault is restored, the current fault response is cleared to ensure the robustness of vehicle operation when the vehicle is short-term intermittent BUS off.

[0022] Embodiment 2 Reference Figures 1 to 5 , the new energy vehicle network fault diagnosis method according to the embodiment of the present invention comprises: The SCU shift controller control unit sends the gear request (P, R, N, D) signal to the power domain control through the CAN network by identifying the driver's shift operation; ABS anti-lock braking system, which collects four-wheel speed signals to calculate vehicle speed and sends the vehicle speed signal to the power domain controller through the CAN network; ESP electronic body stability system, which sends an activation signal to the power domain controller when activated; The NBS line controller system sends the electric brake energy recovery demand signal to the power domain controller through the CAN network; The SWM combination switch control unit sends the cruise control switch request signal from the driver's cruise control button operation to the power domain controller via the CAN network; The IC instrument display control unit and PEPS are a one-button start system. The power domain controller integrates the traditional VCU vehicle control unit, MCU motor controller, BMS battery management system, DCDC DC-to-DC control module, and OBC on-board charger control unit functions, and mainly controls the vehicle's powertrain.

[0023] First, the power domain controller determines that the vehicle is in a drivable mode. In this mode, it detects whether the vehicle confirms that the CAN bus is off. If so, the IC instrument prompts the light to turn on. Because the ABS speed signal cannot be transmitted to the power domain controller, the power domain controller no longer uses the ABS speed to calculate the speed, but uses the motor speed to calculate the speed (u=0.377nr / igi0). Then determine whether the vehicle is in cruise control before the CAN BUS off fault is confirmed. If so, exit cruise control. Here, because the communication with the chassis brake system controller is interrupted, the system cannot guarantee the stability of the cruise control function and needs to exit cruise control. Otherwise, determine whether the driver wants to enter the cruise control by pressing the on / off key before the CAN BUS off fault is confirmed. If so, the cruise control is prohibited. The on / off key is defined as the combination switch controller sending the CAN communication to the power domain controller. If the power domain controller directly collects the data by hard wire, the cruise control can be entered. Otherwise, it is determined whether the vehicle is in the braking energy recovery process before the CAN BUS off fault is confirmed. If so, the braking energy recovery torque request is exited. Since the communication between the power domain controller and the braking system is interrupted, it is impossible to ensure that the vehicle brakes are unstable, so it is necessary to exit from a safety perspective; Otherwise, it is further determined whether the vehicle speed before the CAN BUS off fault is confirmed is ≤3kph. If so, the domain control executes the control of returning the associated vehicle speed to N gear. Since the communication with the gear controller is lost here, the current gear can be maintained at high speeds, but the driving gear needs to be exited at low speeds to ensure safety. Further determine whether the current bus BUS off fault has been restored. If so, clear the vehicle response measures and the sample vehicle is still in the drivable mode. According to the network specification, when the CAN bus BUS off occurs, each controller needs to perform five fast recoveries and multiple slow recoveries until the network communication returns to normal.

[0024] The key point and protection point of this invention is to propose a new fault diagnosis response measure method for the vehicle CAN bus BUS OFF fault. Different diagnostic measures are given for the power domain controller and distributed powertrain controller of new energy vehicles respectively. By identifying different scene conditions and exiting the corresponding driving function to ensure the safety of vehicle operation, the current fault response is cleared when the fault is restored to maintain the robustness of the vehicle.

[0025] Secondly, the power domain controller determines whether the vehicle is in charging mode. Figure 4 In this mode, the vehicle is tested to see if the CAN bus is off. If so, the IC instrument will light up. Because the ABS speed signal cannot be transmitted to the power domain controller, the domain controller no longer uses the ABS speed to calculate the speed, but uses the motor speed to calculate the speed (u=0.377nr / igi0). The next step is to determine whether the vehicle is in the plug-in charging state before the CAN BUS off fault is confirmed. If so, determine whether the vehicle speed is ≤3kph. If so, charging is still allowed; otherwise, the charging domain controller is not allowed to enter sleep mode. The next step is to determine whether the vehicle is charging before the CAN BUS off fault is confirmed. If so, the charging is still maintained, otherwise the domain controller enters sleep mode; Next, the power domain controller determines whether the current BUS off fault has been restored. If so, the vehicle response measures are cleared and the sample vehicle remains in charging mode.

[0026] The present invention proposes a new fault diagnosis response measure method for the vehicle CAN bus BUS OFF fault for the power domain controller and the distributed powertrain controller of the new energy vehicle. When the vehicle is in a drivable state, the vehicle can still ensure normal driving in the current state when the CAN bus BUS off occurs, but it is necessary to analyze the driving function of the specific scenario working condition of the sample vehicle to exit the response to ensure the safety of vehicle operation. When the CAN bus BUS OFF fault is restored, the current fault response is cleared to ensure the robustness of vehicle operation when the vehicle is short-term intermittent BUS off.

[0027] Embodiment 3 Reference Figures 1 to 5 , the new energy vehicle network fault diagnosis method according to the embodiment of the present invention comprises: The SCU shift controller control unit sends the gear request (P, R, N, D) signal to the power domain control through the CAN network by identifying the driver's shift operation; ABS anti-lock braking system, which collects four-wheel speed signals to calculate vehicle speed and sends the vehicle speed signal to the power domain controller through the CAN network; ESP electronic body stability system, which sends an activation signal to the power domain controller when activated; The NBS line controller system sends the electric brake energy recovery demand signal to the power domain controller through the CAN network; The SWM combination switch control unit sends the cruise control switch request signal from the driver's cruise control button operation to the power domain controller via the CAN network; The IC instrument display control unit and PEPS are a one-button start system. The power domain controller integrates the traditional VCU vehicle control unit, MCU motor controller, BMS battery management system, DCDC DC-to-DC control module, and OBC on-board charger control unit functions, and mainly controls the vehicle's powertrain.

[0028] First, the power domain controller determines that the vehicle is in a drivable mode. In this mode, it detects whether the vehicle confirms that the CAN bus is off. If so, the IC instrument prompts the light to turn on. Because the ABS speed signal cannot be transmitted to the power domain controller, the power domain controller no longer uses the ABS speed to calculate the speed, but uses the motor speed to calculate the speed (u=0.377nr / igi0). Then determine whether the vehicle is in cruise control before the CAN BUS off fault is confirmed. If so, exit cruise control. Here, because the communication with the chassis brake system controller is interrupted, the system cannot guarantee the stability of the cruise control function and needs to exit cruise control. Otherwise, determine whether the driver wants to enter the cruise control by pressing the on / off key before the CAN BUS off fault is confirmed. If so, the cruise control is prohibited. The on / off key is defined as the combination switch controller sending the CAN communication to the power domain controller. If the power domain controller directly collects the data by hard wire, the cruise control can be entered. Otherwise, it is determined whether the vehicle is in the braking energy recovery process before the CAN BUS off fault is confirmed. If so, the braking energy recovery torque request is exited. Since the communication between the power domain controller and the braking system is interrupted, it is impossible to ensure that the vehicle brakes are unstable, so it is necessary to exit from a safety perspective; Otherwise, it is further determined whether the vehicle speed before the CAN BUS off fault is confirmed is ≤3kph. If so, the domain control executes the control of returning the associated vehicle speed to N gear. Since the communication with the gear controller is lost here, the current gear can be maintained at high speeds, but the driving gear needs to be exited at low speeds to ensure safety. Further determine whether the current bus BUS off fault has been restored. If so, clear the vehicle response measures and the sample vehicle is still in the drivable mode. According to the network specification, when the CAN bus BUS off occurs, each controller needs to perform five fast recoveries and multiple slow recoveries until the network communication returns to normal.

[0029] The key point and protection point of this invention is to propose a new fault diagnosis response measure method for the vehicle CAN bus BUS OFF fault. Different diagnostic measures are given for the power domain controller and distributed powertrain controller of new energy vehicles respectively. By identifying different scene conditions and exiting the corresponding driving function to ensure the safety of vehicle operation, the current fault response is cleared when the fault is restored to maintain the robustness of the vehicle.

[0030] Secondly, the power domain controller determines whether the vehicle is in charging mode. Figure 4 In this mode, the vehicle is tested to see if the CAN bus is off. If so, the IC instrument will light up. Because the ABS speed signal cannot be transmitted to the power domain controller, the domain controller no longer uses the ABS speed to calculate the speed, but uses the motor speed to calculate the speed (u=0.377nr / igi0). The next step is to determine whether the vehicle is in the plug-in charging state before the CAN BUS off fault is confirmed. If so, determine whether the vehicle speed is ≤3kph. If so, charging is still allowed; otherwise, the charging domain controller is not allowed to enter sleep mode. The next step is to determine whether the vehicle is charging before the CAN BUS off fault is confirmed. If so, the charging is still maintained, otherwise the domain controller enters sleep mode; Next, the power domain controller determines whether the current BUS off fault has been restored. If so, the vehicle response measures are cleared and the sample vehicle remains in charging mode.

[0031] The present invention proposes a new fault diagnosis response measure method for the vehicle CAN bus BUS OFF fault for the power domain controller and the distributed powertrain controller of the new energy vehicle. When the vehicle is in a drivable state, the vehicle can still ensure normal driving in the current state when the CAN bus BUS off occurs, but it is necessary to analyze the driving function of the specific scenario working condition of the sample vehicle to exit the response to ensure the safety of vehicle operation. When the CAN bus BUS OFF fault is restored, the current fault response is cleared to ensure the robustness of vehicle operation when the vehicle is short-term intermittent BUS off.

[0032] The present invention has the functions of a separate VCU vehicle controller, an MCU motor controller, a BMS battery management system, a DCDC DC to DC control module and an OBC on-board charger control unit.

[0033] In this embodiment, the distributed powertrain controller first detects whether the vehicle confirms the CAN bus BUS off fault (here mainly refers to the VCU vehicle controller judgment). If so, the IC instrument prompts the light to further determine whether the vehicle is in a drivable mode. If so, the next step is to exit the driving mode. Here, because the direct communication between the controller is interrupted, especially the communication between the vehicle controller and the motor controller is interrupted, in order to ensure safety, it is necessary to cut off the power to exit the driving mode; Otherwise, it is further determined whether it is in charging mode. If so, charging is prohibited. Since the communication between the vehicle controller and the battery management system is interrupted, the battery thermal management status cannot be monitored during charging. To ensure charging safety, charging needs to be prohibited. The VCU further detects whether the CAN bus BUS off is restored. If restored, it restores the drivable mode in the driving mode and restores the charging mode in the charging mode, clears the vehicle response measures, and the vehicle resumes normal functions.

[0034] The present invention aims at the current situation that after the controller of a new energy vehicle diagnoses that the vehicle CAN bus is BUS off (Note: CAN bus BUS off is a more serious network failure), due to communication interruption, the existing method usually cuts off the power output under the severe response measures of high voltage, but does not identify and execute the response measures for the current scene working condition; The network fault diagnosis method of the present invention is a control method for ensuring that the vehicle can maintain a normal driving state and needs to execute different response measures in combination with scene conditions. It solves the problem that the domain controller of the new energy vehicle can not only ensure the continuous driving of the sample vehicle but also execute protection response measures for the whole vehicle in different scenarios when the whole vehicle CAN bus BUSoff occurs. Thereby improving the advantages and robustness of the domain controller. For the new energy vehicle divided controller, when the whole vehicle CAN bus BUS off is diagnosed, different response measures are adopted for different scenarios in combination with fault confirmation and fault recovery, which ensures the safety of the vehicle and personnel and maximizes the robustness of the vehicle.

[0035] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A new energy vehicle network fault diagnosis method, characterized in that: include: The SCU shift controller control unit sends the gear request (P, R, N, D) signal to the power domain control through the CAN network by identifying the driver's shift operation; ABS anti-lock braking system, which collects four-wheel speed signals to calculate vehicle speed and sends the vehicle speed signal to the power domain controller through the CAN network; ESP electronic stability system, which sends an activation signal to the power domain controller when activated; The NBS line controller system sends the electric brake energy recovery demand signal to the power domain controller through the CAN network; The SWM combination switch control unit sends the cruise control switch request signal from the driver's cruise control button operation to the power domain controller via the CAN network; The IC instrument display control unit and PEPS are a one-button start system. The power domain controller integrates the traditional VCU vehicle control unit, MCU motor controller, BMS battery management system, DCDC DC-to-DC control module, and OBC on-board charger control unit functions, and mainly controls the vehicle's powertrain.

2. The new energy vehicle network fault diagnosis method according to claim 1 is characterized in that: The power domain controller determines that the vehicle is in a drivable mode. In this mode, it detects whether the vehicle confirms the CAN bus BUS off fault. If so, the IC instrument prompt lights up in the next step. Because the ABS vehicle speed signal cannot be transmitted to the power domain controller, the power domain controller no longer uses the ABS vehicle speed to calculate the vehicle speed, and uses the motor speed to calculate the vehicle speed (u=0.377nr / igi0).

3. The new energy vehicle network fault diagnosis method according to claim 2 is characterized in that: Determine whether the vehicle is in cruise control before the CANBUS off fault is confirmed. If so, exit cruise control. Here, due to the interruption of communication with the chassis brake system controller, the system cannot guarantee the stability of the cruise control function and needs to exit cruise control.

4. The new energy vehicle network fault diagnosis method according to claim 3 is characterized in that: Otherwise, determine whether the driver wants to enter the cruise control by pressing the switch key before the CAN BUS off fault is confirmed. If so, entering the cruise control is prohibited. The switch key here is defined as the combination switch controller sending it to the power domain controller through CAN communication. If the power domain controller directly collects the data through hard wire, the cruise control can be entered.

5. The new energy vehicle network fault diagnosis method according to claim 4 is characterized in that: Otherwise, determine whether the vehicle is in the braking energy recovery process before the CAN BUS off fault is confirmed. If so, exit the braking energy recovery torque request. Here, since the communication between the power domain controller and the braking system is interrupted, it is impossible to ensure that the vehicle's braking is unstable, so it is necessary to exit from a safety perspective.

6. The new energy vehicle network fault diagnosis method according to claim 5 is characterized in that: Otherwise, further determine whether the vehicle speed before CAN BUS off fault confirmation is ≤3kph. If so, the domain control executes the associated vehicle speed to return to N gear control. Here, due to the loss of communication with the gear controller, the current gear can be maintained at high speeds, and it is necessary to exit the driving gear at low speeds to ensure safety.

7. The new energy vehicle network fault diagnosis method according to claim 6 is characterized in that: Further determine whether the current bus BUS off fault has been restored. If so, clear the vehicle response measures and the sample vehicle is still in the drivable mode. According to the network specification, when the CAN bus BUS off occurs, each controller needs to perform five fast recoveries and multiple slow recoveries until the network communication returns to normal.

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