Vehicle control unit driving protection control method for new energy vehicle

Abstract

The invention relates to the technical field of vehicle control of new energy vehicles, in particular to a driving protection control method for a vehicle control unit of a new energy vehicle, which comprises the following specific steps: S1, VCU bottom software monitors pin driving states of a water pump, a three-way valve and a two-way valve in real time; s2, fault state setting of any part of the water pump, the three-way valve and the two-way valve is judged; s3, the underlying software transmits the fault state interface variable to the application layer, and the application layer software reports the summary fault of the part; s4, the application layer software updates a part state signal message, and packages and sends out the part state signal message; s5, the application layer control logic resets a part driving signal and transmits the signal to bottom layer software, the driving chip cancels driving output, and the problem that when a switch valve and a water pump drive of a heat management system at the present stage have a short-circuit fault, although the chip is protected by hardware of the chip, driving is stopped, but the software always gives a driving instruction, and the driving efficiency is affected is solved. And potential safety hazards exist on hardware.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle integrated control, and specifically, the present invention relates to a driving protection control method for a new energy vehicle integrated controller. Background Art

[0002] The VCU of a new energy vehicle, as the core control unit of the vehicle, is responsible for the state control and coordination of the core components of the vehicle, including functions such as driver intention analysis, longitudinal and lateral control, vehicle thermal management, and energy management. Some components are driven by the VCU, such as the on-off valve of the thermal management system or the PWM type water pump drive, etc. The interface of the VCU responsible for driving these components is driven by a dedicated chip. If a short-circuit fault occurs, although the chip has its own hardware protection to stop driving, if the software layer always gives a driving instruction, there is still a hardware protection safety hazard in extreme cases for the hardware itself. Summary of the Invention

[0003] The present invention provides a driving protection control method for a new energy vehicle integrated controller, which solves the problem that when a short-circuit fault occurs in the on-off valve and water pump drive of the thermal management system at the present stage, although the chip has its own hardware protection to stop driving, the software always gives a driving instruction, which poses a safety hazard to the hardware itself.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A driving protection control method for a new energy vehicle integrated controller, the new energy vehicle is a series hybrid vehicle, the series hybrid vehicle includes an APU, the APU includes an engine and a generator, and also includes a water pump, a three-way valve, and a two-way valve. The specific steps are as follows: Step S1, the VCU bottom layer software monitors the pin driving states of the water pump, the three-way valve, and the two-way valve in real time; Step S2, determine whether the fault state of any part of the water pump, the three-way valve, and the two-way valve is set. If so, execute Step S3; Step S3, the bottom layer software transfers the fault state interface variable to the application layer, and the application layer software reports the summary fault of the component; Step S4, the application layer software updates the component status signal message and packs it for external transmission; Step S5, the application layer control logic resets the component driving signal and transfers it to the bottom layer software, and the driving chip cancels the driving output.

[0005] Further defined, the liquid heat liquid on the low-temperature side of the battery needs to be driven and circulated by the water pump. The driving operation of the water pump needs to judge whether the two-way valve is normal and opened. The battery liquid heat and liquid cooling share a set of thermal management circuits, and the three-way valve is used to switch the liquid cooling and liquid heat circuits.

[0006] Further limitation: For the control of the two-way valve, when the battery has a thermal management requirement, the APU engine is in the running state, the engine coolant temperature is higher than the threshold, and the water pump is fault-free, the VCU determines that the drive output condition is met, sets HVB2WayVlvReq, and transmits it to the underlying software. After receiving it, the underlying software interacts with the hardware drive layer, and the hardware drive layer directly drives the hardware output. When the battery has no thermal management requirement, or the APU engine is not in the running state, or the engine coolant temperature is lower than the threshold, or the drive pin of the two-way valve itself is faulty, or the battery coolant inlet temperature is lower than the threshold, the VCU determines that the stop drive output condition is met, resets HVB2WayVlvReq, and transmits it to the underlying software. After receiving it, the underlying software interacts with the hardware drive layer, and the hardware drive layer cancels the drive hardware output. If the VCU controls the two-way valve to close temporarily after the engine coolant temperature is lower than the threshold or the battery inlet temperature is higher than the threshold, when the battery inlet temperature is lower than the threshold and the opening condition in step 10 is met, the VCU will control the two-way valve to open again.

[0007] Further limitation: For the control of the water pump, when the battery has a thermal management requirement, keeping the water pump, two-way valve, three-way valve fault-free, the two-way valve in the drive state, and the engine coolant temperature higher than the threshold, the VCU determines that the drive output condition is met, sets HVBHeatingReqWaterPumpEnaSts, and transmits it to the underlying software. After receiving it, the underlying software interacts with the hardware drive layer, and the hardware drive layer directly drives the hardware output. When the drive output condition is met, the VCU will control the water pump to run at full speed to maximize the battery heating speed and effect. When the battery has no thermal management requirement, or one of the water pump, two-way valve, and three-way valve is faulty, or the two-way valve is not in the drive state, or the engine coolant temperature is lower than the threshold, the VCU determines that the stop drive output condition is met, resets HVBHeatingReqWaterPumpEnaSts, and transmits it to the underlying software. After receiving it, the underlying software interacts with the hardware drive layer, and the hardware drive layer cancels the drive hardware output.

[0008] Further limitation: Since the battery thermal management and the passenger compartment heating share the engine coolant as the heat source, when the battery is heated, if there is a heating request in the passenger compartment, in order to prevent the battery heating from affecting the heating effect of the passenger compartment, the VCU will control the water pump to derate. The VCU dynamically controls the derating amplitude of the battery water pump according to the opening of the cold and warm air damper issued by the air-conditioning control panel CLM. The larger the opening of the cold and warm air damper, the greater the derating amplitude of the battery water pump, and the maximum derating does not exceed 60%.

[0009] Further limitation: for the control of the three-way valve, when the battery has a thermal management requirement, the water pump is fault-free, the water pump is in the drive output state, and the three-way valve itself is fault-free, the VCU determines that the drive output condition is met, sets HVB3WayVlvSts and transmits it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer directly drives the hardware output. When the battery has no thermal management requirement, the water pump fails, or the drive pin of the three-way valve itself fails, the VCU determines that the stop drive output condition is met, resets HVB3WayVlvSts and transmits it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer cancels the drive of the hardware output.

[0010] Further limitation: for the control of the APU, since the battery itself has a heating film, it can be heated by the heating film alone. To maximize economy and avoid increasing the engine fuel consumption for heating the battery and ensure the economy of the user's vehicle use, when there is a separate liquid heating requirement for the battery, the VCU will not control the start of the APU. When there is a heating request in the passenger compartment and the whole vehicle uses the engine coolant as the heating heat source, the VCU will control the start of the APU to provide the heating heat source for the passenger compartment.

[0011] Further limitation: when the APU is in the operating state, the VCU will normally respond to the heating requirement of the BMS. When it is determined that the relevant conditions are met, it will drive the relevant components for heat exchange. When the inlet temperature is higher than the threshold value, the VCU will control the water pump to stop rotating to prevent the two-way valve from failing to close, and the water pump runs continuously to heat the battery, resulting in battery overheating and alarm.

[0012] Further limitation: for the temperature equalization request of the battery, the VCU will control the water pump to run at full speed to quickly perform temperature equalization control on the battery cells. When the temperature difference of the battery is large, it will send a temperature equalization request. If the battery temperature difference becomes too large after heating the battery with the engine coolant, the BMS will request temperature equalization, and the VCU will control the three-way valve to be in the state of bypassing the radiator and the fan. When the battery requests temperature equalization, the three-way valve control is independently switched to bypass the battery radiator and the fan to accelerate the temperature equalization speed and improve the temperature equalization effect. The beneficial effects of adopting the above technical solutions are: By performing real-time fault monitoring on the drive pins, when the fault status obtained by the application layer software is set, the VCU believes that the drive pins of the component have failed, and then stops the drive output of the component. First, when the drive pins fail at the software level, it can avoid invalid drive control and reduce the software operation load rate. Second, at the hardware level, it can effectively protect the pin drive chip. By designing the drive control functional safety control strategy, it can effectively protect the pin drive chip, reduce the software operation load under fault conditions, and save the CPU resource occupancy of software operation. Description of the Drawings

[0013] Figure 1 This is the control flow chart of the two-way valve of the present invention; Figure 2 This is the control flow chart of the water pump of the present invention; Figure 3 This is the control flow chart of the three-way valve of the present invention; Figure 4 This is the control flow chart for handling drive protection faults of the present invention; Figure 5 This is the control strategy flow chart for the battery equal-temperature request of the present invention. Detailed implementation manners

[0014] The following is a detailed description of the specific implementation manners of the present invention by referring to the accompanying drawings and through the description of the embodiments, aiming to help those skilled in the art have a more complete, accurate, and in-depth understanding of the concept and technical solution of the present invention, and to facilitate its implementation.

[0015] The present invention is a drive protection control method for a new energy vehicle vehicle controller, which solves the problem that at the current stage, by performing real-time fault monitoring on the drive pins, when the fault status obtained by the application layer software is set, the VCU considers that a fault has occurred in the drive pins of the component, and then stops the drive output of the component. First, when there is a drive pin fault at the software level, invalid drive control can be avoided to reduce the software operation load rate. Second, at the hardware level, the pin drive chip can be effectively protected. By designing a drive control functional safety control strategy, the pin drive chip can be effectively protected, the software operation load under fault conditions can be reduced, and the CPU resource occupancy of software operation can be saved.

[0016] The new energy vehicle is a series hybrid vehicle. The series hybrid vehicle includes an APU. The APU is equipped with an engine and a generator. Part of the heat generated during the operation of the engine is utilized for heating in the passenger compartment, and the other part can be used for liquid heating in battery thermal management. When the engine is running, the engine coolant can be circulated, and convection occurs with the liquid in the Chiller and the liquid thermal pipeline on the battery side, so as to transfer the heat of the engine coolant to the liquid in the low-temperature side battery heating circuit. The liquid thermal liquid on the low-temperature side of the battery needs to be driven by a water pump to circulate, and the driving operation of the water pump requires judging whether the two-way valve for controlling the engine coolant on the high-temperature side is normal and open. Otherwise, the heat of the engine coolant cannot be taken out by the driving operation of the low-temperature side water pump for battery heating. The battery liquid heating and liquid cooling share a set of thermal management circuits. The battery cooling needs to dissipate the heat in the coolant into the air, and the battery is cooled by a radiator and a fan. When using the waste heat of the engine to heat the battery, the radiator and the cooling fan for battery cooling need to be bypassed to prevent the heat in the engine coolant from being dissipated into the air on the low-temperature side and wasted. The three-way valve is used to switch the liquid cooling and liquid heating circuits. When heating the battery in winter, the three-way valve acts to bypass the radiator and the cooling fan, while when cooling the battery in summer, the three-way valve connects the battery radiator and the cooling fan circuit to cool the battery. When the three-way valve is used for battery liquid heating control and driving, it is necessary to judge the operation and fault status of the battery water pump. If the battery water pump is not running or a fault is detected, then the VCU will stop the driving output of the three-way valve and maintain the default driving state of the three-way valve.

[0017] For the driving protection of the two-way valve on the high-temperature side of the engine, the VCU real-time detects the fault status of the driving pin of the two-way valve. If a short circuit fault occurs, the driving output will be immediately stopped. For the driving protection of the water pump on the low-temperature side of the battery, the VCU real-time detects the fault status of the driving pin of the water pump. If a short circuit fault occurs, the driving output will be immediately stopped. For the driving protection of the three-way valve on the low-temperature side of the battery, the VCU real-time detects the fault status of the driving pin of the three-way valve. If a short circuit fault occurs, the driving output will be immediately stopped.

[0018] For the control of the two-way valve, when the battery has a thermal management requirement, the APU's engine is in operation, the engine coolant temperature is higher than the threshold, and the water pump is fault-free, the VCU determines that the drive output condition is met, sets HVB2WayVlvReq, and passes it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer directly drives the hardware output. When the battery has no thermal management requirement, or the APU's engine is not in operation, or the engine coolant temperature is lower than the threshold, or the drive pin of the two-way valve itself is faulty, or the battery coolant inlet temperature is lower than the threshold, the VCU determines that the stop drive output condition is met, resets HVB2WayVlvReq, and passes it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer cancels the drive hardware output. If the engine coolant temperature is lower than the threshold or the battery inlet temperature is higher than the threshold, causing the VCU to control the two-way valve to close temporarily, when the battery inlet temperature is less than the threshold, the VCU will control the two-way valve to open again.

[0019] For the control of the water pump, when the battery has a thermal management requirement, the water pump is fault-free, the two-way valve is fault-free, the three-way valve is fault-free, the two-way valve is in the drive state, and the engine coolant temperature is higher than the threshold, the VCU determines that the drive output condition is met, sets HVBHeatingReqWaterPumpEnaSts, and passes it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer directly drives the hardware output. When the drive output condition is met, the VCU will control the water pump to run at full speed to maximize the battery heating speed and effect. When the battery has no thermal management requirement, or the water pump is faulty, or the two-way valve is faulty, or the three-way valve is faulty, or the two-way valve is not in the drive state, or the engine coolant temperature is lower than the threshold, the VCU determines that the stop drive output condition is met, resets HVBHeatingReqWaterPumpEnaSts, and passes it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer cancels the drive hardware output.

[0020] Since the battery thermal management and the passenger compartment heating share the engine coolant as the heat source, when the battery is being heated, if there is a heating request in the passenger compartment, then at this time, in order to prevent the battery heating from affecting the heating effect of the passenger compartment, the VCU will control the water pump to derate. The VCU dynamically controls the derate amplitude of the battery water pump according to the opening degree of the cold and warm air damper issued by the air conditioning control panel CLM. The larger the opening degree of the cold and warm air damper, the greater the derate amplitude of the battery water pump, and the maximum derate does not exceed 60%. According to the actual measurement, it can not only ensure the heating requirement of the passenger compartment, but also improve the battery heating effect.

[0021] For the control of the three-way valve, when the battery has a thermal management requirement, the water pump is fault-free, the water pump is in the drive output state, and the three-way valve itself is fault-free, the VCU determines that the drive output condition is met, sets the HVB3WayVlvSts and transmits it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer directly drives the hardware output. When the battery has no thermal management requirement, or the water pump fails, or the drive pin of the three-way valve itself fails, the VCU determines that the stop drive output condition is met, resets the HVB3WayVlvSts and transmits it to the underlying software. The underlying software receives it and interacts with the hardware drive layer, and the hardware drive layer cancels the drive of the hardware output.

[0022] For the control of the APU, since the battery itself has a heating film, it can be heated by the heating film alone. To maximize economy and avoid increasing the engine fuel consumption for battery heating to ensure the economy of user vehicle use, when there is a separate liquid heating requirement for the battery, the VCU will not control the start of the APU. When there is a heating request in the passenger compartment, since the whole vehicle uses engine coolant as the heating heat source, the VCU will control the start of the APU to provide heating heat source for the passenger compartment. When the APU is in the running state, the VCU will normally respond to the heating requirement of the BMS, and when it judges that the relevant conditions are met, it will drive the relevant components for heat exchange. When the inlet temperature is higher than the threshold, the VCU will control the water pump to stop rotating to prevent the two-way valve from failing to close, and the water pump runs continuously to heat the battery, resulting in battery overheating and alarm.

[0023] To optimize the memory resources of the VCU and reduce the memory occupancy of the software code, the pin drive faults of the water pump, two-way valve and three-way valve will be integrated. All types of faults of each component are combined into one fault, including short circuit to power supply, short circuit to ground or open circuit faults. By setting fault signals, the fault signals characterize the specific fault types of each fault, which can not only reduce the memory resource occupancy of the fault code, but also do not affect the problem location and solution after the fault is reported. The VCU packs the drive states of the two-way valve, three-way valve and water pump into message signals and sends them to the bus to facilitate data viewing by after-sales service engineers without calibration tools or other component engineers. The signal definition is as follows: 0x0 represents default closed, 0x1 represents drive, and 0x2 represents fault.

[0024] For the request of equalizing the temperature of the battery, the VCU will control the water pump to run at full speed to quickly control the temperature equalization of the battery cells. If the battery requests temperature equalization and there is a heating request in the passenger compartment at the same time, the duty cycle of the water pump will still maintain the maximum output at this time because the two-way valve is already in the closed state, and the full-speed operation of the water pump will not affect the high-temperature side and cause the temperature of the high-temperature side to drop. When the temperature difference of the battery is large, the battery will issue a request for temperature equalization. If the battery temperature difference becomes too large after heating the battery with the engine coolant, the BMS will request temperature equalization, and the VCU will control the three-way valve to bypass the radiator and the fan. When the battery requests temperature equalization, the three-way valve control is independently switched to bypass the battery radiator and the fan to accelerate the temperature equalization speed and improve the temperature equalization effect. There is no scenario with a large temperature difference in summer, and it only occurs in winter. Therefore, the VCU only needs to judge the battery temperature equalization request to jointly control the water pump and the three-way valve for synchronous control.

[0025] The present invention has been described exemplarily in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention; or without improvement, the above-mentioned concept and technical solution of the present invention are directly applied to other occasions, they are all within the protection scope of the present invention.

Claims

1. A method for controlling driving protection of a vehicle controller of a new energy vehicle, wherein the new energy vehicle is a series hybrid vehicle, the series hybrid vehicle comprises an APU, and the APU comprises an engine and a generator, and is characterized in that: It also includes a water pump, a three-way valve and a two-way valve. The specific steps are as follows: Step S1, the VCU bottom-level software monitors the pin drive status of the water pump, three-way valve and two-way valve in real time; Step S2, determining whether any part of the water pump, the three-way valve, or the two-way valve is in a fault state; Step S3, the bottom layer software transmits the fault status interface variable to the application layer, and the application layer software reports the summary fault of the component; Step S4, the application layer software updates the component status signal message and packages it for external transmission; Step S5, the application layer control logic resets the component drive signal and transmits it to the underlying software, and the driver chip cancels the drive output.

2. A new energy vehicle controller drive protection control method according to claim 1, characterized in that: The liquid heat liquid on the low-temperature side of the battery needs to be driven by the water pump to circulate. The driving operation of the water pump requires judging whether the two-way valve is normal and open. The battery liquid heat and liquid cooling share a set of thermal management circuits, and the three-way valve is used to switch the liquid cooling and liquid heat circuits.

3. A new energy vehicle controller drive protection control method according to claim 2, characterized in that: For the control of the two-way valve, when the battery has a thermal management requirement, and the engine of the APU is in operation, and the engine coolant temperature is higher than the threshold, and the water pump has no faults, the VCU determines that the drive output condition is met, and sets HVB2WayVlvReq to the underlying software. The underlying software receives and interacts with the hardware driver layer, and the hardware driver layer directly drives the hardware output. When the battery has no thermal management requirement, or the engine of the APU is not in operation, or the engine coolant temperature is lower than the threshold, or the two-way valve itself drives the pin fault, or the battery coolant inlet temperature is lower than the threshold, the VCU determines that the stop drive output condition is met, and resets HVB2WayVlvReq to the underlying software. The underlying software receives and interacts with the hardware driver layer, and the hardware driver layer cancels the drive hardware output. If the engine coolant temperature is lower than the threshold or the battery inlet temperature is higher than the threshold, the VCU controls the two-way valve to be temporarily closed. If the battery inlet temperature is lower than the threshold and the opening condition in step 10 is met, the VCU will control the two-way valve to open again.

4. A new energy vehicle controller drive protection control method according to claim 2, Features: For the control of the water pump, when the battery has thermal management requirements, the water pump is kept fault-free, the two-way valve is fault-free, the three-way valve is fault-free, the two-way valve is in a driving state, and the engine coolant temperature is higher than the threshold. The VCU determines that the drive output conditions are met, and sets HVBHeatingReqWaterPumpEnaSts to the underlying software. The underlying software receives and interacts with the hardware driver layer. The hardware driver layer directly drives the hardware output. When the drive output conditions are met, the VCU will control the water pump to run at full speed to maximize the battery heating speed and effect; when the battery has no thermal management requirements or one of the water pump, two-way valve, or three-way valve is faulty, or the two-way valve is not in a driving state, or the engine coolant temperature is lower than the threshold, the VCU determines that the drive output stop conditions are met, and resets HVBHeatingReqWaterPumpEnaSts to the underlying software. The underlying software receives and interacts with the hardware driver layer, and the hardware driver layer cancels the drive hardware output.

5. A new energy vehicle controller drive protection control method according to claim 4, characterized in that: Since the battery thermal management and passenger compartment heating share the engine coolant as the heat source, when the battery is heated, if the passenger compartment has a heating request, then at this time, in order to prevent the battery heating from affecting the heating effect of the passenger compartment, the VCU will control the water pump derating. The VCU dynamically controls the battery water pump derating according to the opening of the heating and cooling air doors sent by the air-conditioning control panel CLM. The larger the opening of the heating and cooling air doors, the greater the derating of the battery water pump, and the maximum derating does not exceed 60%.

6. A new energy vehicle controller drive protection control method according to claim 2, characterized in that: For the control of the three-way valve, when the battery has thermal management requirements, the water pump has no faults, the water pump is in a drive output state, and the three-way valve itself has no faults, the VCU determines that the drive output conditions are met, and sets HVB3WayVlvSts to the underlying software. The underlying software receives and interacts with the hardware driver layer, and the hardware driver layer directly drives the hardware output. When the battery has no thermal management requirements or the water pump fails, or the drive pin of the three-way valve itself fails, the VCU determines that the conditions for stopping the drive output are met, and resets HVB3WayVlvSts to the underlying software. The underlying software receives and interacts with the hardware driver layer, and the hardware driver layer cancels the drive hardware output.

7. A new energy vehicle controller drive protection control method according to claim 2, characterized in that: Regarding the control of the APU, since the battery itself has a heating film, it can heat itself only through the heating film. In order to maximize economy, avoid increasing engine fuel consumption by heating the battery, and ensure the economy of the user's vehicle, when there is a separate liquid thermal heating demand for the battery, the VCU will not control the start of the APU. When there is a heating request in the passenger compartment, the vehicle uses the engine coolant as the heating source, and the VCU will control the start of the APU to provide a heating source for the passenger compartment.

8. A new energy vehicle controller drive protection control method according to claim 2, characterized in that: When the APU is in operation, the VCU will respond normally to the heating needs of the BMS. When it determines that the relevant conditions are met, it will drive the relevant components to perform heat exchange. When the water inlet temperature is higher than the threshold, the VCU will control the water pump to stop to prevent the two-way valve from failing and being unable to close. The water pump will continue to heat the battery, causing the battery to overheat and alarm.

9. A new energy vehicle controller drive protection control method according to claim 2, characterized in that: For the battery's temperature equalization request, the VCU will control the water pump to run at full speed to quickly balance the temperature of the battery cells. The battery will issue a temperature equalization request when the temperature difference is large. If the battery temperature difference is too large after using the engine coolant to heat the battery, the BMS will request temperature equalization. The VCU will control the three-way valve to bypass the radiator and fan. When the battery requests temperature equalization, the three-way valve control will be independently converted to bypass the battery radiator and fan to speed up the temperature equalization speed and improve the temperature equalization effect.

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