Control method, control device and processor of pure electric four-wheel drive system

Abstract

The present invention discloses a control method, a control device and a processor for a pure electric four-wheel drive system. The method includes: obtaining fault information of assembly components of the pure electric four-wheel drive system, wherein the assembly components include at least one of the following: a power battery, a front axle motor, a rear axle motor, and a clutch, and the clutch is arranged between the front axle motor and the front wheel of the vehicle; determining the fault type of the assembly components based on the fault information, wherein the fault type includes at least one of the following: a first fault type, a second fault type, and a third fault type; generating a control instruction set based on the fault type, and the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode. The present invention solves the technical problem that the pure electric four-wheel drive system cannot perform limp control according to the fault classification of each assembly component, resulting in low safety of the pure electric four-wheel drive vehicle.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a control method, a control device and a processor of a pure electric four-wheel drive system. Background Art

[0002] At present, pure electric vehicles are developing faster and faster. In order to pursue better power, many models adopt four-wheel drive solutions, that is, one electric drive system is used in the front and rear. Permanent magnet synchronous motors are widely used in pure electric vehicles due to their high power density and high efficiency. However, unlike asynchronous motors, permanent magnet synchronous motors have a large reverse torque under the rotating condition, and in order to prevent the back electromotive force from being too high, the weak magnetic current in the high speed section is large, and more electric energy is consumed. All of these lead to high power consumption and short driving range of four-wheel drive models using permanent magnet synchronous motors, which affects the competitiveness of the models. In order to reduce the loss of motor rotation, many electric four-wheel drive vehicles currently add a clutch between the motor and the transmission mechanism. In the prior art, the pure electric four-wheel drive system with assembly components such as clutches cannot perform failure limp control according to the fault classification of each assembly component in the system, resulting in low safety and reliability of pure electric four-wheel drive vehicles.

[0003] Currently, no effective solution has been proposed for the problem that the pure electric four-wheel drive system is unable to perform limp homeostasis control according to the fault classification of each assembly component in the system, resulting in low safety of the pure electric four-wheel drive vehicle. Summary of the invention

[0004] The embodiments of the present invention provide a control method, a control device and a processor for a pure electric four-wheel drive system, so as to at least solve the technical problem that the pure electric four-wheel drive system cannot perform limp home control according to the fault classification of each assembly component, resulting in low safety of the pure electric four-wheel drive vehicle.

[0005] According to one aspect of an embodiment of the present invention, a control method for a pure electric four-wheel drive system is provided, comprising: obtaining fault information of assembly components of the pure electric four-wheel drive system, wherein the assembly components include at least one of the following: a power battery, a front axle motor, a rear axle motor, and a clutch, and the clutch is arranged between the front axle motor and the front wheel of the vehicle; determining a fault type of the assembly components based on the fault information, wherein the fault type includes at least one of the following: a first fault type, a second fault type, and a third fault type, wherein the first fault type includes a fault that causes a safety risk to the entire vehicle, the second fault type includes a fault that causes a complete failure of the assembly components, and the third fault type includes a fault that does not affect the normal operation of the assembly components; generating a control instruction set based on the fault type, the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, wherein the preset working mode includes at least one of the following: a safety mode, a parking mode, a power-limited limp mode, a rear axle drive motor two-wheel drive limp mode, a front axle drive motor two-wheel drive limp mode, a forced four-wheel drive limp mode, and a torque compensation mode.

[0006] Optionally, a control instruction set is generated based on the fault type, including: when the fault information of the power battery is a first fault type, generating a first control instruction in the control instruction set, the first control instruction being used to control the pure electric four-wheel drive system to enter a safety mode, wherein when the pure electric four-wheel drive system is in the safety mode, the high-voltage relay of the power battery is in a triggered state, the front axle motor and the rear axle motor are both in a no-torque output state, and the clutch is in a disconnected state.

[0007] Optionally, generating a control instruction set based on the fault type also includes: when the fault information of the power battery is a third fault type, generating a second control instruction in the control instruction set, the second control instruction being used to control the pure electric four-wheel drive system to enter a power-limited limp mode, wherein when the pure electric four-wheel drive system is in the power-limited limp mode, the output power of the front axle motor and the rear axle motor are both less than the allowable power of the power battery.

[0008] Optionally, generating a control instruction set based on the fault type also includes: when the fault information of the front axle motor is the second fault type, generating a third control instruction in the control instruction set, the third control instruction is used to control the pure electric four-wheel drive system to enter the rear axle drive motor two-wheel drive limp mode, wherein, when the pure electric four-wheel drive system is in the rear axle drive motor two-wheel drive limp mode, the front axle motor is in a no-torque output state, the clutch is in a disconnected state, and the rear axle motor outputs the driving power required by the driver.

[0009] Optionally, generating a control instruction set based on the fault type also includes: when the fault information of the rear axle motor is the second fault type, generating a fourth control instruction in the control instruction set, the fourth control instruction being used to control the pure electric four-wheel drive system to enter the two-wheel drive limp mode of the front axle drive motor, wherein, when the pure electric four-wheel drive system is in the two-wheel drive limp mode of the front axle drive motor, the rear axle motor is in a no-torque output state, the clutch is in an engaged state, the front axle motor outputs the driving power required by the driver, and the output power of the front axle motor is less than a preset power.

[0010] Optionally, generating a control instruction set based on the fault type also includes: when one of the fault information of the front axle motor and the fault information of the rear axle motor is a third fault type, generating a fifth control instruction in the control instruction set, the fifth control instruction being used to control the pure electric four-wheel drive system to enter a torque compensation mode, wherein when the pure electric four-wheel drive system is in the torque compensation mode, one of the front axle motor and the rear axle motor outputs the driving power required by the driver, and the other of the front axle motor and the rear axle motor outputs the torque compensation power.

[0011] Optionally, the second fault type of the clutch includes a clutch engagement fault and a clutch disengagement fault, and generating a control instruction set based on the fault type also includes: when the clutch fault information is a clutch disengagement fault, generating a sixth control instruction in the control instruction set, the sixth control instruction being used to control the pure electric four-wheel drive system to enter a forced four-wheel drive limp mode, wherein when the pure electric four-wheel drive system is in the forced four-wheel drive limp mode, the clutch is in an engaged state, and the front axle motor and the rear axle motor jointly output the output power required by the driver.

[0012] Optionally, generating a control instruction set based on the fault type also includes: when the clutch fault information is a clutch engagement fault, generating one of the seventh control instruction and the third control instruction in the control instruction set, the seventh control instruction is used to control the pure electric four-wheel drive system to enter a parking mode, wherein when the pure electric four-wheel drive system is in the parking mode, the front axle motor and the rear axle motor are both in a no-torque output state, and the clutch is in a disconnected state.

[0013] According to another aspect of an embodiment of the present invention, a control device for a pure electric four-wheel drive system is also provided, including: an acquisition module, used to acquire fault information of assembly components of the pure electric four-wheel drive system, wherein the assembly components include at least one of the following: a power battery, a front axle motor, a rear axle motor, and a clutch, and the clutch is arranged between the front axle motor and the front wheel of the vehicle; a determination module, used to determine the fault type of the assembly components based on the fault information, wherein the fault type includes at least one of the following: a first fault type, a second fault type, and a third fault type, the first fault type includes a fault that causes a safety risk to the entire vehicle, the second fault type includes a fault that causes a complete failure of the assembly components, and the third fault type includes a fault that does not affect the normal operation of the assembly components; a generation module, used to generate a control instruction set based on the fault type, the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, wherein the preset working mode includes at least one of the following: a safety mode, a parking mode, a power-limited limp mode, a rear axle drive motor two-wheel drive limp mode, a front axle drive motor two-wheel drive limp mode, a forced four-wheel drive limp mode, and a torque compensation mode.

[0014] According to another aspect of the embodiments of the present invention, a processor is provided. The processor is used to run a program. The program is configured to execute the above-mentioned control method of the pure electric four-wheel drive system when running.

[0015] In an embodiment of the present invention, a method of obtaining fault information of assembly components of a pure electric four-wheel drive system is adopted, by determining the fault type of the assembly components based on the fault information, and generating a control instruction set based on the fault type, the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, thereby achieving the purpose of selecting different failure limp home modes according to the different fault types of each assembly component of the pure electric four-wheel drive system, thereby solving the technical problem that the pure electric four-wheel drive system cannot perform failure limp home control according to the fault classification of each assembly component, resulting in low safety of the pure electric four-wheel drive vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 is a hardware structure block diagram of an electronic device of a vehicle according to a control method of a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0018] Figure 2 is a flow chart of a control method of a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0019] Figure 3is a structural schematic diagram of a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0020] Figure 4 is a structural schematic diagram of a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0021] Figure 5 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0022] Figure 6 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0023] Figure 7 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0024] Figure 8 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0025] Fig. 9 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0026] Fig.10 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0027] Fig.11 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0028] Fig.12 is a flow chart of a control method for a pure electric four-wheel drive system according to one optional embodiment of the present invention;

[0029] Fig.13 It is a structural block diagram of a control device for a pure electric four-wheel drive system according to one optional embodiment of the present invention.

[0030] The above drawings include the following reference numerals:

[0031] 1. Front axle reducer; 2. Clutch; 3. Front axle drive motor; 4. Rear axle drive motor; 5. Rear axle reducer; 6. Front axle wheel; 7. Front axle motor inverter; 8. Rear axle motor inverter; 9. High-voltage relay; 10. High-voltage battery; 11. Rear axle wheel; 12. Clutch controller; 13. Front axle drive motor controller; 14. Rear axle drive motor controller; 15. High-voltage battery management system; 16. Vehicle controller; 17. Instrument display system. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] According to one embodiment of the present invention, an embodiment of a control method for a pure electric four-wheel drive system is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in an order different from that shown here.

[0035] The method embodiment can be executed in an electronic device or similar computing device in a vehicle including a memory and a processor. For example, Figure 1 As shown, the electronic device of the vehicle may include one or more processors 102 (the processor may include but is not limited to a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP) chip, a microprocessor (MCU), a programmable logic device (FPGA), a neural network processor (NPU), a tensor processor (TPU), an artificial intelligence (AI) fault type processor, etc.) and a memory 104 for storing data. Optionally, the electronic device of the above-mentioned car may also include a transmission device 106 for communication functions, an input and output device 108, and a display 110. It can be understood by those skilled in the art that Figure 1The structure shown is for illustration only and does not limit the structure of the electronic device of the vehicle. For example, the electronic device of the vehicle may include more or fewer components than those described in the above structure, or may have a configuration different from that described in the above structure.

[0036] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the control method of the pure electric four-wheel drive system in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, the control method of the pure electric four-wheel drive system described above is realized. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the mobile terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0037] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0038] The display 110 may be, for example, a touch screen type liquid crystal display (LCD) and a touch display (also referred to as a "touch screen" or a "touch display screen"). The liquid crystal display may enable a user to interact with a user interface of the mobile terminal. In some embodiments, the mobile terminal has a graphical user interface (GUI), and a user may interact with the GUI by finger contact and / or gestures on a touch-sensitive surface, wherein the human-computer interaction functions here may optionally include the following interactions: creating web pages, drawing, word processing, making electronic documents, games, video conferencing, instant messaging, sending and receiving emails, call interfaces, playing digital videos, playing digital music and / or web browsing, etc. The executable instructions for executing the above human-computer interaction functions are configured / stored in a computer program product or a readable storage medium executable by one or more processors.

[0039] In order to reduce the rotation loss of the permanent magnet synchronous motor during driving and increase the driving range, many pure electric vehicles currently add a clutch between the drive motor and the transmission mechanism. The clutch diagnosis in the prior art is usually for the clutch fault diagnosis itself, and no limp-in-failure design is performed for the pure electric four-wheel drive system with a clutch. In addition, the existing vehicle limp-in-failure control method cannot respond to different faults according to the severity of the obstacles of each assembly component. Therefore, how to design a new limp-in-failure control method for a pure electric four-wheel drive system to improve the safety and reliability of four-wheel drive pure electric vehicles has become a technical problem that needs to be solved urgently.

[0040] It should be noted that vehicle limp means that when the electronic control system of the car fails, it can still complete basic functions, allowing the car to run at the lowest performance level. At this time, the missing control signal of the vehicle will be replaced by other signals or preset parameters. It can be seen that the control of the vehicle in the limp state is crucial to improving the safety of the vehicle.

[0041] This embodiment provides a control method for a pure electric four-wheel drive system of an electronic device running on the above vehicle. Figure 2 is a flow chart of a control method of a pure electric four-wheel drive system according to one embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0042] Step S10, obtaining fault information of assembly components of the pure electric four-wheel drive system, wherein the assembly components include at least one of the following: a power battery, a front axle motor, a rear axle motor, and a clutch, and the clutch is arranged between the front axle motor and the front wheels of the vehicle;

[0043] Optionally, by collecting fault information from controllers corresponding to each assembly component, when an assembly component fails, a corresponding fault code is generated and stored in the corresponding controller. More specifically, the clutch is arranged between the front axle motor and the front axle drive train. The clutch has an engaged state and a disengaged state.

[0044] Step S20, determining the fault type of the assembly component based on the fault information, wherein the fault type includes at least one of the following: a first fault type, a second fault type, and a third fault type, wherein the first fault type includes a fault that causes a safety risk to the entire vehicle, the second fault type includes a fault that causes a complete failure of the assembly component, and the third fault type includes a fault that does not affect the normal operation of the assembly component;

[0045] That is to say, the fault types of each assembly component are classified and graded. The first fault type includes faults that affect the safety performance of the entire vehicle and pose a serious threat to the vehicle and passengers. For example, the first fault type includes the temperature of the power battery significantly exceeding the safety threshold. The second fault type includes no response to the control signal of the front axle motor. It should be noted that in the present application, the high-voltage battery is the power battery, the front axle drive motor is the front axle motor, and the rear axle drive motor is the rear axle motor. Specifically, the first fault type is actually a safety fault in the conventional sense, the second fault type is a serious fault in the conventional sense, and the third fault type is a general fault in the conventional sense. When the third fault type occurs in an assembly component, the function is usually only degraded or the function is not affected.

[0046] Step S30, generating a control instruction set based on the fault type, the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, wherein the preset working mode includes at least one of the following: a safety mode, a parking mode, a power-limited limp mode, a rear axle drive motor two-wheel drive limp mode, a front axle drive motor two-wheel drive limp mode, a forced four-wheel drive limp mode, and a torque compensation mode;

[0047] That is, each assembly controller monitors and identifies its own fault status in real time, and sends it to the vehicle controller through the CAN line; the vehicle controller receives the assembly fault status, identifies its own fault and CAN communication fault, and classifies the fault into severity levels, including faults that affect vehicle safety, serious faults (complete failure), and general faults (functional degradation). The vehicle controller performs corresponding limp home control based on the severity level. The vehicle limp home modes include safety mode, parking mode, power-limited limp home mode, rear axle drive motor two-wheel drive limp home mode, front axle drive motor two-wheel drive limp home mode, forced four-wheel drive limp home mode, alarm mode, and torque compensation mode.

[0048] Through the above steps, the fault information of the assembly components of the pure electric four-wheel drive system is obtained, the fault type of the assembly components is determined based on the fault information, and a control instruction set is generated based on the fault type. The control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, so as to achieve the purpose of selecting different failure limp modes according to the different fault types of each assembly component of the pure electric four-wheel drive system, thereby solving the technical problem that the pure electric four-wheel drive system cannot perform failure limp control according to the fault classification of each assembly component, resulting in low safety of the pure electric four-wheel drive vehicle. In combination with the technical solution of this embodiment, a failure limp control method for a four-wheel drive pure electric vehicle equipped with a clutch is provided. The method takes into account the impact of the failure of each assembly component on the vehicle, and formulates an effective limp control method, which greatly improves the safety and reliability of the four-wheel drive pure electric vehicle.

[0049] like Figure 3As shown, a schematic diagram of the structure of a pure electric four-wheel drive system is provided. The pure electric four-wheel drive system consists of two power sources, the front axle drive motor 3 and the rear axle drive motor 4. The high-voltage relay 9 is closed, and the high-voltage battery 10 provides power to the front axle drive motor 3 and the rear axle drive motor 4 through the front axle motor inverter 7 and the rear axle motor inverter 8. When the clutch 2 is closed, the front axle drive motor 3 is transmitted to the wheels through the front axle reducer 1. The torque output by the rear axle drive motor 4 is transmitted to the wheels through the rear axle reducer 5. The front axle drive motor 3 and the rear axle drive motor 4 can output torque simultaneously or separately to drive the vehicle. Figure 4 The figure shows a schematic diagram of a limp-run control device for a four-wheel drive pure electric system. Each assembly in the four-wheel drive pure electric system is monitored and adjusted by a dedicated controller, such as the front axle drive motor 3 is controlled by the front axle drive motor controller 13, the rear axle drive motor 4 is controlled by the rear axle drive motor controller 14, the high-voltage battery 10 is controlled by the high-voltage battery management system 15, and the clutch 2 is controlled by the clutch control unit. Each assembly controller monitors and identifies its own fault state in real time, and sends it to the vehicle controller 16 through the CAN line. The vehicle controller 16 identifies the driver's operation, receives the relevant component information and fault information sent by the controllers such as the motor, battery, and clutch, sends control instructions to the relevant controllers, coordinates and controls all components (motor, battery, clutch) to operate in an orderly manner, realizes the functions of pure electric two-wheel drive, four-wheel drive and brake energy recovery, and ensures that the vehicle operates safely and reliably according to the driver's needs in the event of a fault. In addition, when a key assembly fails and the vehicle enters the limp-run mode, the vehicle controller 16 sends an instruction to the instrument display system 17 to light up the fault indicator light corresponding to the power system fault, and prompts the driver through text whether to stop in a safe area or limp to the maintenance station.

[0050] The pure electric four-wheel drive system includes key assemblies such as the front axle drive motor, rear axle drive motor, high-voltage battery, clutch, and reducer. The motor, clutch, and high-voltage battery assembly are all monitored and adjusted by a proprietary controller. The vehicle controller identifies the driver's operation, receives relevant component information and fault information sent by the motor, battery, clutch, and other controllers, sends control instructions to the relevant controllers, coordinates and controls all components (motor, battery, clutch) to operate in an orderly manner, realizes pure electric drive and brake energy recovery functions, and ensures that the vehicle operates safely and reliably according to the driver's needs in the event of a fault.

[0051] Optionally, generating a control instruction set based on the fault type includes: when the fault information of the power battery is of the first fault type, generating a first control instruction in the control instruction set, the first control instruction is used to control the pure electric four-wheel drive system to enter a safe mode, wherein when the pure electric four-wheel drive system is in the safe mode, the high-voltage relay of the power battery is in a triggered state, the front axle motor and the rear axle motor are both in a no-torque output state, and the clutch is in a disconnected state. Figure 5 As shown, when the vehicle collides or the high-voltage battery fails in a way that affects the safety of the vehicle and its passengers, the vehicle controller immediately disconnects the high-voltage relay, controls the front axle drive motor to output zero torque, controls the rear axle drive motor to output zero torque, and controls the clutch to disengage, so as to control the vehicle to enter safety mode.

[0052] In an optional embodiment, if Figure 6 As shown, in response to the power battery fault information being the second fault type, that is, when a serious fault occurs in the high-voltage battery, the vehicle controller immediately controls the front axle drive motor to output zero torque, controls the rear axle drive motor to output zero torque, controls the clutch to disengage, and controls the high-voltage relays to disconnect in sequence, so as to control the vehicle to enter parking mode.

[0053] Optionally, generating a control instruction set based on the fault type further includes: when the fault information of the power battery is of the third fault type, generating a second control instruction in the control instruction set, the second control instruction is used to control the pure electric four-wheel drive system to enter a power-limited limp home mode, wherein when the pure electric four-wheel drive system is in the power-limited limp home mode, the output power of the front axle motor and the rear axle motor are both less than the allowable power of the power battery. Figure 8 As shown, that is to say, when a general fault occurs in the high-voltage battery, resulting in limited output power, the vehicle controller controls the front axle drive motor and the rear axle drive motor to meet the driver's needs as much as possible without exceeding the allowable power of the high-voltage battery, and the vehicle enters the power-limited limp home mode.

[0054] like Fig. 9 As shown, generating a control instruction set based on the fault type also includes: when the fault information of the front axle motor is the second fault type, generating a third control instruction in the control instruction set, the third control instruction is used to control the pure electric four-wheel drive system to enter the rear axle drive motor two-wheel drive limp mode, wherein, when the pure electric four-wheel drive system is in the rear axle drive motor two-wheel drive limp mode, the front axle motor is in a no-torque output state, the clutch is in a disconnected state, and the rear axle motor outputs the driving power required by the driver.

[0055] Optionally, generating a control instruction set based on the fault type also includes: when the fault information of the rear axle motor is the second fault type, generating a fourth control instruction in the control instruction set, the fourth control instruction is used to control the pure electric four-wheel drive system to enter the front axle drive motor two-wheel drive limp mode, wherein when the pure electric four-wheel drive system is in the front axle drive motor two-wheel drive limp mode, the rear axle motor is in a state of no torque output, the clutch is in a state of engagement, the front axle motor outputs the driving power required by the driver, and the output power of the front axle motor is less than the preset power. Fig.10 As shown, when a serious fault occurs in the rear axle drive motor causing the output torque to be zero, the vehicle controller 16 controls the clutch to engage and controls the front axle drive motor to drive the vehicle. Taking into account the back electromotive force of the rear axle drive motor, the vehicle controller limits the maximum speed of the vehicle and the vehicle enters the front drive motor two-wheel drive limp mode.

[0056] Optionally, generating a control instruction set based on the fault type further includes: generating a fifth control instruction in the control instruction set when one of the fault information of the front axle motor and the fault information of the rear axle motor is of the third fault type, and the fifth control instruction is used to control the pure electric four-wheel drive system to enter a torque compensation mode, wherein when the pure electric four-wheel drive system is in the torque compensation mode, one of the front axle motor and the rear axle motor outputs the driving power required by the driver, and the other of the front axle motor and the rear axle motor outputs the torque compensation power. Fig.12 As shown, that is to say, when the front axle drive motor fails seriously or the clutch cannot engage, the vehicle controller controls the front axle drive motor to output zero torque, controls the clutch to disengage, controls the rear axle drive motor to drive the vehicle, and enters the rear axle drive motor two-wheel drive limp mode.

[0057] Optionally, the second clutch fault type includes a clutch engagement fault and a clutch disengagement fault, and generating a control instruction set based on the fault type further includes: generating a sixth control instruction in the control instruction set when the clutch fault information is a clutch disengagement fault, and the sixth control instruction is used to control the pure electric four-wheel drive system to enter a forced four-wheel drive limp mode, wherein when the pure electric four-wheel drive system is in the forced four-wheel drive limp mode, the clutch is in an engaged state, and the front axle motor and the rear axle motor jointly output the output power required by the driver. Fig.11 As shown, that is to say, when the clutch fails to disengage, the vehicle controller controls the clutch to remain engaged, controls the front axle drive motor and the rear axle drive motor to jointly drive the vehicle, and enters the forced four-wheel drive limp mode.

[0058] Optionally, generating a control instruction set based on the fault type also includes: when the clutch fault information is a clutch engagement fault, generating one of the seventh control instruction and the third control instruction in the control instruction set, the seventh control instruction is used to control the pure electric four-wheel drive system to enter a parking mode, wherein when the pure electric four-wheel drive system is in the parking mode, the front axle motor and the rear axle motor are both in a no-torque output state, and the clutch is in a disconnected state.

[0059] like Figure 7 As shown, when the first preset condition and the second preset condition are met at the same time or the second preset condition and the third preset condition are met at the same time, the vehicle controller immediately controls the front axle drive motor to output zero torque, controls the rear axle drive motor to output zero torque, and controls the clutch to disengage, so as to control the vehicle to enter the parking mode. Among them, the first preset condition is the failure of the front axle drive motor, the third preset condition is that the clutch cannot be engaged, and the second preset condition is a serious failure of the rear axle drive motor.

[0060] In an optional embodiment, when the vehicle controller 16 identifies a CAN communication failure of the assembly controller, since the working state and fault state of the key assembly cannot be accurately obtained, the control is performed according to the limp mode of the serious fault of the assembly. Since the limp mode gradually decreases in severity in the order of safety mode, parking mode, power-limited limp mode, rear axle drive motor two-wheel drive limp mode, front axle drive motor two-wheel drive limp mode, forced four-wheel drive limp mode, and alarm mode, when a serious level assembly fault occurs, the limp mode with a high severity level is entered first, so that when multiple faults are triggered at the same time, not only can superimposed fault handling measures be adopted, but the whole vehicle can also enter a safer limp mode.

[0061] Specifically, when a general fault occurs in the front axle drive motor or the rear axle drive motor, resulting in limited output torque, the vehicle controller controls another motor to compensate for the torque, thereby ensuring the driver's needs, and the vehicle enters the alarm mode. When a key assembly fails and the vehicle enters the limp mode, a command is sent to the instrument display system to light up the fault indicator light corresponding to the power system fault, and the driver is prompted by text whether to stop in a safe area or limp to the repair station. When the vehicle controller identifies a CAN communication failure in the assembly controller, since it is unable to accurately obtain the working status and fault status of the key assembly, it is controlled according to the limp mode of the serious fault of the assembly. When multiple assemblies fail at the same time, superimposed fault handling measures are adopted, and the most serious level of limp mode is entered.

[0062] In an optional embodiment, the clutch controller 12, the front axle drive motor controller 13, the rear axle drive motor controller 14, and the high-voltage battery management system 15 monitor their own operating status data in real time and identify their own fault status, and send it to the vehicle controller 16 through the CAN line. Secondly, the vehicle controller 16 receives the assembly fault status, identifies its own fault and CAN communication fault, and classifies the fault into severity levels, including faults that affect vehicle safety, serious faults (complete failure), and general faults (functional degradation). Finally, the vehicle controller performs corresponding limp home control according to the severity level: when the vehicle collides or the high-voltage battery 10 has a fault that affects the safety of the vehicle and the driver and passengers, the vehicle controller 16 immediately controls the high-voltage relay 9 to disconnect, controls the front axle drive motor 3 to output zero torque, controls the rear axle drive motor 4 to output zero torque, and controls the clutch 2 to separate, so as to control the vehicle to enter the safety mode; when the high-voltage battery 10 has a serious fault, the vehicle controller 16 immediately controls the front axle drive motor 3 to output zero torque, controls the rear axle drive motor 4 to output zero torque, controls the clutch 2 to separate, and controls the high-voltage relays to disconnect in sequence, so as to control the vehicle to enter the parking mode; when (the front axle drive motor fails or the clutch cannot be engaged) AND the rear axle drive motor 4 fails, the clutch 2 is disconnected, and the high-voltage relays are disconnected in sequence, so as to control the vehicle to enter the parking mode. When the motor fails seriously, the vehicle controller 16 immediately controls the front axle drive motor 3 to output zero torque, controls the rear axle drive motor 4 to output zero torque, and controls the clutch 2 to disengage, so as to control the vehicle to enter the parking mode; when the high-voltage battery 10 has a general fault and the output power is limited, the vehicle controller 16 controls the front axle drive motor 3 and the rear axle drive motor 4 to meet the driver's needs as much as possible without exceeding the allowable power of the high-voltage battery, and the vehicle enters the limited power limp mode; when the front axle drive motor 3 fails seriously or the clutch 2 cannot engage, the vehicle controller 16 controls the front axle drive motor 3 to output zero torque, controls the clutch 2 to disengage, and controls the rear axle drive motor 4 to drive the vehicle, and enters the rear axle drive motor two-wheel drive limp mode. When the rear axle drive motor 4 has a serious fault causing the output torque to be zero, the vehicle controller 16 controls the clutch 2 to engage and controls the front axle drive motor 3 to drive the vehicle. Considering the problem of the back electromotive force of the rear axle drive motor 4, the vehicle controller limits the maximum speed of the vehicle, and the vehicle enters the front drive motor two-wheel drive limp mode; when the clutch 2 cannot be separated, the vehicle controller 16 controls the clutch 2 to remain engaged, controls the front axle drive motor 3 and the rear axle drive motor 4 to drive the vehicle together, and enters the forced four-wheel drive limp mode; when the front axle drive motor 3 or the rear axle drive motor 4 has a general fault causing the output torque to be limited, the vehicle controller 16 controls another motor to compensate for the torque, thereby ensuring the driver's needs, and the vehicle enters the alarm mode. When a key assembly fails and the vehicle enters the limp mode, the vehicle controller 16 sends a command to the instrument display system 17 to light up the fault indicator light corresponding to the power system fault, and prompts the driver through text whether to stop in a safe area or limp to the maintenance station.

[0063] Fig.13 is a structural block diagram of a control device for a pure electric four-wheel drive system according to one embodiment of the present invention. Fig.13 As shown, the device includes: an acquisition module 51, which is used to obtain fault information of the assembly components of the pure electric four-wheel drive system, wherein the assembly components include at least one of the following: a power battery, a front axle motor, a rear axle motor, and a clutch, and the clutch is arranged between the front axle motor and the front wheel of the vehicle; a determination module 52, which is used to determine the fault type of the assembly components based on the fault information, wherein the fault type includes at least one of the following: a first fault type, a second fault type, and a third fault type, the first fault type includes a fault that causes a safety risk to the entire vehicle, the second fault type includes a fault that causes a complete failure of the assembly components, and the third fault type includes a fault that does not affect the normal operation of the assembly components; a generation module 53, which is used to generate a control instruction set based on the fault type, and the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, wherein the preset working mode includes at least one of the following: a safety mode, a parking mode, a power-limited limp mode, a rear axle drive motor two-wheel drive limp mode, a front axle drive motor two-wheel drive limp mode, a forced four-wheel drive limp mode, and a torque compensation mode.

[0064] Through the above-mentioned device, a method of obtaining fault information of assembly components of a pure electric four-wheel drive system is adopted, by determining the fault type of the assembly components based on the fault information, and generating a control instruction set based on the fault type, the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, thereby achieving the purpose of selecting different failure limp home modes according to the different fault types of each assembly component of the pure electric four-wheel drive system, thereby solving the technical problem that the pure electric four-wheel drive system cannot perform failure limp home control according to the fault classification of each assembly component, resulting in low safety of the pure electric four-wheel drive vehicle.

[0065] It should be noted that the above modules can be implemented by software or hardware. For the latter, it can be implemented in the following ways, but not limited to: the above modules are all in the same processor; or the above modules are in different processors in any combination.

[0066] An embodiment of the present invention further provides a processor, which is configured to run a computer program to execute the steps in any of the above method embodiments.

[0067] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here.

[0068] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0069] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0070] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0071] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0072] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0073] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A control method for a pure electric four-wheel drive system, characterized in that: include: Acquiring fault information of an assembly component of a pure electric four-wheel drive system, wherein the assembly component includes at least one of the following: a power battery, a front axle motor, a rear axle motor, and a clutch, and the clutch is disposed between the front axle motor and the front wheels of the vehicle; Determining a fault type of the assembly component based on the fault information, wherein the fault type includes at least one of the following: a first fault type, a second fault type, and a third fault type, wherein the first fault type includes a fault that causes a safety risk to the entire vehicle, the second fault type includes a fault that causes complete failure of the assembly component, and the third fault type includes a fault that does not affect normal operation of the assembly component; generating a control instruction set based on the fault type, the control instruction set being used to control the pure electric four-wheel drive system to enter a preset working mode, wherein the preset working mode comprises at least one of the following: a safety mode, a parking mode, a power-limited limp mode, a rear axle drive motor two-wheel drive limp mode, a front axle drive motor two-wheel drive limp mode, a forced four-wheel drive limp mode, and a torque compensation mode; Generating a control instruction set based on the fault type also includes: generating a third control instruction in the control instruction set when the fault information of the front axle motor is the second fault type, the third control instruction is used to control the pure electric four-wheel drive system to enter the two-wheel drive limp mode of the rear axle drive motor, wherein when the pure electric four-wheel drive system is in the two-wheel drive limp mode of the rear axle drive motor, the front axle motor is in a state of no torque output, the clutch is in a disconnected state, and the rear axle motor outputs the driving power required by the driver; The second fault type of the clutch includes a clutch engagement fault and a clutch disengagement fault, and generating a control instruction set based on the fault type further includes: generating a sixth control instruction in the control instruction set when the fault information of the clutch is the clutch disengagement fault, and the sixth control instruction is used to control the pure electric four-wheel drive system to enter the forced four-wheel drive limp mode, wherein when the pure electric four-wheel drive system is in the forced four-wheel drive limp mode, the clutch is in an engagement state, and the front axle motor and the rear axle motor jointly output the output power required by the driver; Generating a control instruction set based on the fault type also includes: when the fault information of the clutch is the clutch combination fault, generating a seventh control instruction and one of the third control instructions in the control instruction set, the seventh control instruction is used to control the pure electric four-wheel drive system to enter the parking mode, wherein when the pure electric four-wheel drive system is in the parking mode, the front axle motor and the rear axle motor are both in a no-torque output state, and the clutch is in a disconnected state.

2. The control method of the pure electric four-wheel drive system according to claim 1, characterized in that: Generating a control instruction set based on the fault type, including: When the fault information of the power battery is the first fault type, a first control instruction in the control instruction set is generated, and the first control instruction is used to control the pure electric four-wheel drive system to enter the safety mode, wherein when the pure electric four-wheel drive system is in the safety mode, the high-voltage relay of the power battery is in a triggered state, the front axle motor and the rear axle motor are both in a no-torque output state, and the clutch is in a disconnected state.

3. The control method of the pure electric four-wheel drive system according to claim 1, characterized in that: Generating a control instruction set based on the fault type also includes: When the fault information of the power battery is the third fault type, a second control instruction in the control instruction set is generated, and the second control instruction is used to control the pure electric four-wheel drive system to enter the limited power limp home mode, wherein when the pure electric four-wheel drive system is in the limited power limp home mode, the output power of the front axle motor and the rear axle motor are both less than the allowable power of the power battery.

4. The control method of the pure electric four-wheel drive system according to claim 1, characterized in that: Generating a control instruction set based on the fault type also includes: When the fault information of the rear axle motor is the second fault type, a fourth control instruction in the control instruction set is generated, and the fourth control instruction is used to control the pure electric four-wheel drive system to enter the front axle drive motor two-wheel drive limp mode, wherein when the pure electric four-wheel drive system is in the front axle drive motor two-wheel drive limp mode, the rear axle motor is in a no-torque output state, the clutch is in a engaged state, the front axle motor outputs the driving power required by the driver, and the output power of the front axle motor is less than the preset power.

5. The control method of the pure electric four-wheel drive system according to claim 1, characterized in that: Generating a control instruction set based on the fault type also includes: In the case that one of the fault information of the front axle motor and the fault information of the rear axle motor is the third fault type, a fifth control instruction in the control instruction set is generated, and the fifth control instruction is used to control the pure electric four-wheel drive system to enter the torque compensation mode, wherein when the pure electric four-wheel drive system is in the torque compensation mode, one of the front axle motor and the rear axle motor outputs the driving power required by the driver, and the other of the front axle motor and the rear axle motor outputs the torque compensation power.

6. A control device for a pure electric four-wheel drive system, characterized in that: The control device is used to execute the method according to any one of claims 1 to 5, comprising: An acquisition module, used to acquire fault information of an assembly component of a pure electric four-wheel drive system, wherein the assembly component includes at least one of the following: a power battery, a front axle motor, a rear axle motor, and a clutch, and the clutch is arranged between the front axle motor and the front wheel of the vehicle; a determination module, configured to determine a fault type of the assembly component based on the fault information, wherein the fault type includes at least one of the following: a first fault type, a second fault type, and a third fault type, wherein the first fault type includes a fault that causes a safety risk to the entire vehicle, the second fault type includes a fault that causes a complete failure of the assembly component, and the third fault type includes a fault that does not affect the normal operation of the assembly component; A generation module is used to generate a control instruction set based on the fault type, and the control instruction set is used to control the pure electric four-wheel drive system to enter a preset working mode, wherein the preset working mode includes at least one of the following: a safety mode, a parking mode, a power-limited limp mode, a rear-axle drive motor two-wheel drive limp mode, a front-axle drive motor two-wheel drive limp mode, a forced four-wheel drive limp mode, and a torque compensation mode.

7. A processor, characterized in that: The processor is used to run a program, wherein the program is configured to execute the method described in any one of claims 1 to 5 when run.

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