A vehicle four-wheel drive function safety diagnosis control method and vehicle

Abstract

The embodiment of the present invention provides a vehicle four-wheel drive function safety diagnosis control method and a vehicle, the method comprising: obtaining vehicle status data; obtaining a calculated value of a front and rear axle torque distribution ratio coefficient, the calculated value being calculated based on the status data; determining that the calculated value is unreasonable, and setting the value of the front and rear axle torque distribution ratio coefficient to a default value. The default value can be used when the calculated front and rear axle torque distribution ratio coefficient is unreasonable, thereby reducing safety hazards.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to a vehicle four-wheel drive function safety diagnosis and control method and a vehicle. Background Art

[0002] The vehicle's front-to-rear torque distribution coefficient calculated by the Powertrain Control Unit (PCU) may not be within an appropriate range. However, the vehicle does not monitor the rationality of the PCU's calculated front-to-rear torque distribution coefficient. Therefore, if the calculated front-to-rear torque distribution coefficient is unreasonable, the unreasonable front-to-rear torque distribution coefficient will continue to be implemented, posing a safety hazard. Summary of the Invention

[0003] In view of this, an embodiment of the present invention provides a vehicle four-wheel drive function safety diagnosis and control method and a vehicle, which can use default values ​​when the calculated front and rear axle torque distribution ratio coefficient is unreasonable, thereby reducing safety hazards.

[0004] In a first aspect, an embodiment of the present invention provides a vehicle four-wheel drive function safety diagnosis and control method, the method comprising:

[0005] Get vehicle status data;

[0006] Obtaining a calculated value of a front-rear axle torque distribution ratio coefficient, wherein the calculated value is calculated based on the state data;

[0007] It is determined that the calculated value is unreasonable, and the value of the front and rear axle torque distribution proportional coefficient is set to a default value.

[0008] Optionally, setting the value of the front and rear axle torque distribution proportional coefficient to a default value includes:

[0009] The value of the front and rear axle torque distribution proportional coefficient is gradually transitioned from the current value to the default value.

[0010] Optionally, determining that the calculated value is unreasonable includes:

[0011] The calculated value is greater than 1 or less than 0, and it is determined that the calculated value is unreasonable; or

[0012] The calculated value is greater than or equal to 0 and less than or equal to 1. The change rate of the front and rear axle torque distribution ratio coefficient is determined based on the current value of the front and rear axle torque distribution ratio coefficient and the calculated value. The change rate is greater than a first threshold, and it is determined that the calculated value is unreasonable.

[0013] Optionally, the vehicle status data further includes: steering wheel angle and wheel speed data;

[0014] After obtaining the status data of the electric four-wheel drive vehicle, the method further includes:

[0015] determining a state of a first anti-skid flag according to the wheel speed data;

[0016] determining a state of a second anti-skid flag position according to the steering wheel angle, the wheel speed data, the accelerator pedal state, and the brake pedal state;

[0017] When the second anti-skid flag is set and the first anti-skid flag is reset, gradually transitioning the anti-skid control torque from the current value to 0; or

[0018] When the first anti-slip flag is set, the second anti-slip flag is set, and the anti-slip control torque is greater than the required torque, the anti-slip control torque is gradually transitioned from a current value to a first target torque.

[0019] Optionally, after obtaining the status data of the electric four-wheel drive vehicle, the method further includes:

[0020] determining a state of a first differential protection control flag according to the wheel speed data and a second threshold;

[0021] determining a state of a second differential protection control flag according to the wheel speed data and a third threshold;

[0022] When the second differential protection control flag is set and the first differential protection control flag is reset, gradually transitioning the differential protection control torque from the current value to the second target torque; or

[0023] When the first differential protection control flag is set, the second differential protection control flag is set, and the differential protection control torque is greater than the required torque, the differential protection control torque is gradually transitioned from a current value to a third target torque.

[0024] Optionally, the vehicle status data further includes: motor data, shifter position, traffic conditions, high-definition maps, environmental information, and driving mode signals;

[0025] After obtaining the status data of the electric four-wheel drive vehicle, the method further includes:

[0026] Fault monitoring is performed on data in the status data, and faulty data is marked as invalid.

[0027] Optionally, the vehicle status data further includes: an accelerator pedal signal, a brake pedal signal;

[0028] After obtaining the status data of the electric four-wheel drive vehicle, the method further includes:

[0029] The rationality of the accelerator pedal signal and the brake pedal signal is monitored to obtain the accelerator pedal state and the brake pedal state.

[0030] On the other hand, an embodiment of the present invention provides a vehicle comprising a memory and a processor, wherein the memory is used to store information including program instructions, and the processor is used to control the execution of the program instructions, and is characterized in that the program instructions implement the steps of the above-described method when loaded and executed by the processor.

[0031] On the other hand, an embodiment of the present invention provides a computer storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer storage medium is located is controlled to execute the above-mentioned method.

[0032] On the other hand, an embodiment of the present invention provides a computer program product, which includes a stored computer program, wherein when the computer program is running, the device where the computer program product is located is controlled to execute the above-mentioned method.

[0033] In a vehicle four-wheel drive function safety diagnosis and control method and a vehicle technical solution provided by an embodiment of the present invention, the vehicle four-wheel drive function safety diagnosis and control method includes: obtaining vehicle status data, obtaining a calculated value of a front and rear axle torque distribution ratio coefficient, the calculated value being calculated based on the status data; and determining that the calculated value is unreasonable, setting the value of the front and rear axle torque distribution ratio coefficient to a default value. The default value can be used when the calculated front and rear axle torque distribution ratio coefficient is unreasonable, thereby reducing safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flowchart of a vehicle four-wheel drive function safety diagnosis and control method provided by an embodiment of the present invention;

[0035] Figure 2 A flowchart of another vehicle four-wheel drive function safety diagnosis and control method provided by an embodiment of the present invention;

[0036] Figure 3 This is a system architecture diagram for obtaining vehicle status data in an embodiment of the present invention;

[0037] Figure 4 A safety architecture diagram for an AWD system according to an embodiment of the present invention;

[0038] Figure 5 Schematic diagram of anti-skid control monitoring logic in an embodiment of the present invention;

[0039] Figure 6 Schematic diagram of differential protection control monitoring logic in an embodiment of the present invention;

[0040] Figure 7 A schematic structural diagram of a vehicle four-wheel drive function safety diagnosis and control device provided by an embodiment of the present invention;

[0041] Figure 8 A schematic diagram of a vehicle provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0043] It should be understood that the embodiments described are only a portion 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 persons of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0044] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "an", "the" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0045] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0046] With the rapid development of the automotive industry, electric vehicles, especially electric four-wheel drive models, have gradually become the new favorites in the market due to their advantages such as high efficiency and low emissions. Electric four-wheel drive systems achieve more precise power distribution and superior driving performance by independently controlling the motors of the front and rear wheels or left and right wheels. However, while pursuing high performance, functional safety and fault diagnosis have become important aspects of electric four-wheel drive technology that cannot be ignored, mainly reflected in the following aspects:

[0047] ① Ensuring driving safety: The electric four-wheel drive system achieves precise power distribution, improving vehicle controllability and stability. However, any system failure could pose a threat to driving safety, so functional safety is the foundation for ensuring safe driving.

[0048] ② Improve user experience: A stable and reliable four-wheel drive system that can diagnose and handle faults in a timely manner can provide users with a more secure and comfortable driving experience.

[0049] ③ Improve maintenance efficiency: Accurate fault diagnosis results can provide maintenance personnel with valuable information, helping them quickly locate the cause of the fault and take appropriate repairs, thereby shortening maintenance time and reducing maintenance costs.

[0050] Regarding the vehicle's front and rear axle torque distribution ratio coefficient, the front and rear axle torque distribution ratio coefficient calculated by the power control unit PCU may not be within a reasonable range, but the vehicle does not monitor the rationality of the front and rear axle torque distribution ratio coefficient calculated by the PCU, and continues to execute the calculated unreasonable front and rear axle torque distribution ratio coefficient, posing a safety hazard.

[0051] In response to the above technical problems, an embodiment of the present invention provides a vehicle four-wheel drive function safety diagnosis and control method, which can use default values ​​when the calculated front and rear axle torque distribution ratio coefficient is unreasonable, thereby reducing safety hazards.

[0052] Figure 1 A flow chart of a vehicle four-wheel drive function safety diagnosis and control method provided by an embodiment of the present invention is as follows: Figure 1 As shown, the method includes:

[0053] Step 101: Obtain vehicle status data.

[0054] Step 102: Obtain a calculated value of a front and rear axle torque distribution ratio coefficient, where the calculated value is obtained based on the state data.

[0055] Step 103: Determine that the calculated value is unreasonable, and set the value of the front and rear axle torque distribution ratio coefficient to a default value.

[0056] An embodiment of the present invention provides a technical solution for a vehicle four-wheel drive function safety diagnostic control method, comprising: obtaining vehicle status data, obtaining a calculated value of a front and rear axle torque distribution ratio coefficient, the calculated value being calculated based on the status data; and determining that the calculated value is unreasonable, setting the value of the front and rear axle torque distribution ratio coefficient to a default value. Using the default value when the calculated front and rear axle torque distribution ratio coefficient is unreasonable can reduce safety risks.

[0057] Figure 2 A flowchart of another vehicle four-wheel drive function safety diagnosis and control method provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown, the method includes:

[0058] Step 201: Acquire vehicle status data, including motor data, wheel speed data, steering wheel angle, accelerator pedal signal, and brake pedal signal.

[0059] In the embodiment of the present invention, each step is executed by the PCU of the vehicle.

[0060] Among them, status data can also include: shifter position, traffic conditions, high-definition maps, environmental information and driving mode signals.

[0061] For example, Figure 3 FIG. 1 is a system architecture diagram for obtaining vehicle status data in an embodiment of the present invention. Figure 3 As shown in the figure, the PCU obtains motor data from the microcontroller unit (MCU), wheel speed data from the electronic stability control system (ESC), steering wheel angle from the steering wheel angle sensor of the electronic power steering system (EPS), accelerator pedal signal from the accelerator pedal sensor, brake pedal signal from the brake pedal sensor, shifter position from the shift control unit (SCU), traffic conditions and high-definition maps from the telematics box (T-BOX), environmental information from the environmental sensors, and driving mode from the driving mode switch. Dashed lines indicate hardwired connections, and solid lines indicate CAN connections.

[0062] For example, Figure 3 As shown, the PCU sends a motor control mode request and a motor torque request to the MCU, so that the MCU controls the operating mode and output torque of the drive motor according to the motor control mode request and the motor torque request. At the same time, the MCU feeds back motor data to the PCU.

[0063] The motor data includes: the current current of the driving motor, the current temperature of the motor controller, the current temperature of the motor, the current torque of the motor, the current control mode of the motor, the current speed of the motor, the working status of the motor and the current output power of the motor.

[0064] For example, Figure 3 As shown, the wheel speed data includes: the vehicle's four wheel speeds, yaw rate, longitudinal acceleration, lateral acceleration, ESC working status and vehicle speed.

[0065] For example, Figure 3 As shown, the SCU sends the shifter position to the PCU, the PCU performs corresponding operations according to the shifter position, and then feeds back the current gear status of the vehicle to the SCU.

[0066] Illustratively, the environmental sensor may include an environmental temperature sensor, an environmental humidity sensor, and the like.

[0067] For example, the environmental information may include environmental temperature, environmental humidity, etc.

[0068] Therefore, the embodiments of the present invention can achieve real-time and high-precision acquisition of key parameters of the electric four-wheel drive system by optimizing sensor layout and signal processing technology.

[0069] Step 202: Perform fault monitoring on the data in the status data, and mark the faulty data as invalid.

[0070] The embodiment of the present invention also designs all-wheel drive (AWD) software (also called "AWD system"), which is deployed in the PCU to monitor whether the behavior of the vehicle system violates known boundaries and adopts some measures to put the vehicle system into a safe state, thereby realizing multiple redundant safety functions at the software level.

[0071] For example, Figure 4 This is a safety architecture diagram for the AWD system in an embodiment of the present invention, such as Figure 4 As shown, the AWD system includes application software (ASW) Level 1 (L1), ASW Level 2 (L2), Level 3 (L3) + basic software (BSW).

[0072] For example, ASWL1 is the main software used to operate the system, which is usually very complex and needs to include all functional software. Figure 4 As shown, ASWL1 includes PCU function software and AWD function software.

[0073] Among them, the PCU functional software is the basic vehicle driving function control software, which can execute power on and off, starting, acceleration and deceleration, torque control, motor torque request sending, energy management, high-voltage system operation, etc.

[0074] Among them, the AWD function software is the basic function control software of four-wheel drive, which is responsible for the front and rear axle torque distribution, anti-skid control, differential protection control, etc.

[0075] For example, ASW L2 is a security monitoring software, which is a relatively simple software used to monitor whether the system behavior violates known boundaries and can take some actions to put the system into a safe state. Figure 4 As shown, ASW L2 includes PCU safety software and AWD safety software.

[0076] Among them, PCU security software monitors key functions related to PCU functional software security to ensure system security.

[0077] Among them, the AWD safety software monitors key functions related to the safety of the AWD functional software to ensure system safety.

[0078] Level 3 is the controller-level software, primarily monitoring hardware as well as ASW Level 1 and Level 2. L3+BSW ensures the correct execution of the PCU software, provides signal exchange between the PCU and external devices, and performs appliance diagnostics.

[0079] In summary, the AWD system outputs different safety states by diagnosing the input signal, the front and rear axle torque distribution ratio coefficient, the anti-skid control monitoring, and the differential protection control monitoring to ensure the functional safety of the AWD system.

[0080] Therefore, fault monitoring of the data in the status data can be achieved through ASW L1 and ASW L2 in the AWD system, and the faulty data can be marked as invalid.

[0081] by Figure 3 Taking the input signal in as an example, all CAN signals received from the CAN transceiver need to be passed from BSW to ASW. ASW needs to process the signals. ASW L1 and ASW L2 should process these signals respectively.

[0082] For CAN communication inputs, each safety-critical signal requires E2E (End-to-End) protection, and the same operation must be performed on each signal. E2E protection means that the safety-critical signals in these CAN messages include rolling counters and checksums to ensure the integrity of information transmission. When the PCU receives a CAN message, it monitors the timeout, rolling counter, and checksum of each message. If a fault is detected, the corresponding signal is considered invalid when other safety functions are used. This can reduce the impact of fault data on diagnostic results and improve the accuracy of diagnostic results.

[0083] by Figure 3 Taking the input signals in as an example, all signals input from the hard line are read by BSW and passed to ASW. The diagnosis of hard line input signals needs to be assigned to BSW and ASW, and ASW L1 and ASW L2 should process these signals respectively.

[0084] For hard-wired inputs, typical failure modes need to be covered or factored into the diagnosis. If a fault is detected, the corresponding signal should be considered ineffective when other safety functions are used. This can reduce the impact of fault data on diagnostic results and improve diagnostic accuracy.

[0085] Step 203: Monitor the rationality of the accelerator pedal signal and the brake pedal signal to obtain the accelerator pedal state and the brake pedal state.

[0086] In the embodiment of the present invention, L3 monitors the rationality of the brake pedal signal and the accelerator pedal signal.

[0087] L3 needs to perform input signal rationality monitoring, including accelerator pedal signal, brake pedal signal and driving mode signal. The rationality monitoring must be completed before the PCU safety software uses these signals.

[0088] For the accelerator pedal status, the PCU obtains a piece of accelerator pedal information (the first accelerator pedal information) from the accelerator pedal signal. It also calculates another piece of accelerator pedal information (the second accelerator pedal information) based on the status data. If the accelerator pedal signal rationality fault has not occurred, the first accelerator pedal information is used as the accelerator pedal status. If the accelerator pedal signal rationality fault has occurred, the smaller of the first and second accelerator pedal information is used as the accelerator pedal status.

[0089] For the brake pedal status, if the rationality failure of the brake pedal signal does not occur, the brake pedal information in the brake pedal signal is used as the brake pedal status; if the rationality failure of the brake pedal signal occurs, the state in which the brake pedal is not depressed is used as the brake pedal status.

[0090] Step 204 : Obtain a calculated value of the front and rear axle torque distribution ratio coefficient, where the calculated value is obtained based on the state data.

[0091] In this step, ASW L1 calculates the front-to-rear axle torque distribution coefficient based on vehicle status data. Specifically, ASW L1 uses vehicle status information such as steering wheel angle, speed, slope, vehicle weight, longitudinal acceleration, driver torque demand, and driving mode, along with front and rear axle motor efficiency, to determine the front-to-rear axle torque distribution coefficient for different scenarios, taking into account economy, power, and stability.

[0092] Step 205: Determine that the calculated value is unreasonable, and set the value of the front and rear axle torque distribution ratio coefficient to a default value.

[0093] In the embodiment of the present invention, the AWD system needs to monitor whether the front and rear axle torque distribution ratio coefficient calculated by ASW L1 is within a reasonable range.

[0094] In some possible embodiments, determining that the calculated value is unreasonable includes: determining that the calculated value is unreasonable when the calculated value is greater than 1 or less than 0; or

[0095] The calculated value is greater than or equal to 0 and less than or equal to 1. The change rate of the front and rear axle torque distribution ratio coefficient is determined based on the current value and the calculated value of the front and rear axle torque distribution ratio coefficient. If the change rate is greater than the first threshold, it is determined that the calculated value is unreasonable.

[0096] If the front and rear axle torque distribution ratio coefficient R calculated by ASW L1 is greater than 1 or less than 0, it is determined that the front and rear axle torque distribution ratio coefficient R exceeds the range fault and the R calculation is unreasonable.

[0097] If the change rate of the front-rear axle torque distribution ratio coefficient R calculated by ASW L1 is greater than the first threshold, it is determined that a front-rear axle torque distribution ratio coefficient R jump fault occurs and R calculation is unreasonable.

[0098] In some possible embodiments, setting the value of the front and rear axle torque distribution proportional coefficient to a default value includes: gradually transitioning the value of the front and rear axle torque distribution proportional coefficient from a current value to the default value.

[0099] When the front-to-rear axle torque distribution coefficient R received by the PCU from the AWD system is unreasonable, the PCU should provide a default value for R based on the currently monitored hybrid mode. The default value of R can be calibrated, for example: the default value for plug-in hybrid electric vehicles (PHEVs) is 1, the default value for non-PHEVs is 0.6, and the default value for pure electric vehicles is 0.4-0.5.

[0100] The PCU needs to execute the default value of R according to a certain gradient, so that the values ​​of the front and rear axle torque distribution coefficients gradually transition from the current value to the default value, to avoid phenomena such as vehicle jerking caused by rapid switching of the values ​​of the front and rear axle torque distribution coefficients.

[0101] Step 206: Determine the state of the first anti-skid flag according to the wheel speed data.

[0102] In this step, ASW L1 determines whether the vehicle is slipping based on the wheel speed data. If slipping is determined, the first anti-skid flag is set; if not, the first anti-skid flag is reset. The first anti-skid flag is the front or rear axle anti-skid control flag of ASW L1.

[0103] Specifically, taking the front axle anti-skid control flag as an example, when the vehicle is accelerating, when the vehicle speed is less than or equal to 7 kph and the actual shaft speed of the front axle is greater than or equal to 5 kph, the front axle anti-skid control flag is considered to be established (the flag established in this article can be understood as the flag position); when the vehicle speed is greater than or equal to 7 kph and the front axle slip ratio is greater than or equal to 20%, the front axle anti-skid control flag is considered to be established; when the vehicle is decelerating, when the vehicle speed is less than 7 kph and the actual shaft speed of the front axle is less than 5 kph, the front axle anti-skid control flag is considered to be established; when the vehicle speed is greater than 7 kph and the front axle slip ratio is less than 20%, the front axle anti-skid control flag is considered to be established;

[0104] Specifically, taking the rear axle anti-skid control flag as an example, when the vehicle accelerates, when the vehicle speed is less than or equal to 7kph, and the actual axle speed of the rear axle is greater than or equal to 5kph, the rear axle anti-skid control flag is considered to be established; when the vehicle speed is greater than or equal to 7kph, and the rear axle slip rate is greater than or equal to 20%, the rear axle anti-skid control flag is considered to be established; when the vehicle decelerates, when the vehicle speed is less than 7kph, and the actual axle speed of the rear axle is less than 5kph, the rear axle anti-skid control flag is considered to be established; when the vehicle speed is greater than 7kph, and the rear axle slip rate is less than 20%, the rear axle anti-skid control flag is considered to be established.

[0105] Step 207: Determine the state of the second anti-skid flag according to the steering wheel angle, wheel speed data, accelerator pedal state, and brake pedal state.

[0106] In this step, ASW L2 determines whether the vehicle is skidding based on the steering wheel angle, wheel speed data, accelerator pedal status, and brake pedal status. If skidding is determined, the second anti-skid flag is set; if not, the second anti-skid flag is reset. The second anti-skid flag is the ASW L2 front or rear axle anti-skid control flag.

[0107] Specifically, ASW L2 detects vehicle front and rear axle slippage as follows:

[0108] ① When the accelerator pedal opening is greater than 10% and the brake opening is less than 5%, it is in the driving state. If the difference between the highest and lowest wheel speeds among the four wheels is greater than the fourth threshold (this threshold is obtained by looking up the steering wheel angle table), it is determined that the axle with the highest wheel speed is slipping.

[0109] ② When the accelerator pedal opening is less than or equal to 5% and the brake opening is greater than or equal to 10%, it is in the braking state. If the difference between the highest wheel speed and the lowest wheel speed among the four wheels is greater than the fourth threshold (this threshold is obtained by looking up the steering wheel angle table), it is determined that the axle with the lowest wheel speed is slipping.

[0110] Among them, the fourth threshold (converted into vehicle speed kph unit): when the steering wheel angle = 0, the fourth threshold is 20% of the lowest wheel speed (that is, the slip rate is greater than 20%); when the steering wheel angle is not 0, that is, the vehicle is turning, the fourth threshold is 20kph, and a value greater than 20kph is considered to be slipping.

[0111] Step 208: When the second anti-skid flag is set and the first anti-skid flag is reset, the anti-skid control torque is gradually transitioned from the current value to 0; or

[0112] When the first anti-slip flag and the second anti-slip flag are set and the anti-slip control torque is greater than the required torque, the anti-slip control torque is gradually transitioned from the current value to the first target torque.

[0113] The first anti-skid flag is the front axle anti-skid flag of ASW L1, the second anti-skid flag is the front axle anti-skid flag of ASW L2, the anti-skid control torque is the front axle anti-skid control torque of ASW L1, the required torque is the front axle required torque, and the first target torque is the first front axle target torque; or

[0114] The first anti-skid flag is the rear axle anti-skid flag of ASW L1, the second anti-skid flag is the rear axle anti-skid flag of ASW L2, the anti-skid control torque is the rear axle anti-skid control torque of ASW L1, the required torque is the rear axle required torque, and the first target torque is the first rear axle target torque.

[0115] In the embodiment of the present invention, the anti-skid control monitoring includes two parts: one is the monitoring of the anti-skid control flag of ASW L1, and the other is the monitoring of the anti-skid control torque limiting function of ASW L1.

[0116] For example, Figure 5 FIG. 1 is a schematic diagram of the anti-skid control monitoring logic in an embodiment of the present invention, as shown in FIG. Figure 5 As shown in the figure, regarding the monitoring of the anti-slip control flag, if ASW L2 detects slip but the anti-slip control flag of ASW L1 is not set, the ASW L1 anti-slip control flag is determined to be faulty. Because the threshold used by ASW L2 to monitor slip is very high, this is an extreme case. In this case, if the ASW L1 anti-slip flag is faulty, a torque cut request should be triggered. Based on the torque cut request, the PCU gradually transitions the anti-slip control torque from the current value to 0.

[0117] Specifically, the strategy for setting the ASW L2 front or rear axle anti-skid control flag is as follows:

[0118] If ASW L2 determines that the front axle is slipping, but the front axle anti-skid control flag of ASW L1 is not set, then the front axle anti-skid control flag of ASWL2 is set;

[0119] If ASW L2 determines that the rear axle is slipping, but the rear axle anti-skid control flag of ASW L1 is not set, then the rear axle anti-skid control flag of ASWL2 is determined to be set;

[0120] If the front or rear axle anti-skid control flag of ASW L2 is set, the AWD system should send a torque reduction request to gradually transition the anti-skid control torque from the current value to 0.

[0121] like Figure 5As shown in the figure, regarding the monitoring of the anti-slip control torque limit function of ASW L1, if ASW L1 and ASW L2 simultaneously detect slip (both anti-slip flags are set), if the anti-slip control torque of ASW L1 is still greater than the required torque, it is determined that the anti-slip control torque limit of ASW L1 is not being implemented. ASW L2 should gradually reduce the anti-slip control torque to 0. Typically, the required torque during slip is 0.

[0122] For example, after the ASW L1 front or rear axle anti-skid control flag is set, the AWD system should calculate the driver's required torque based on parameters such as the front and rear axle torque distribution ratio monitored by the PCU. The calculation process is as follows:

[0123] When driving:

[0124] Required torque (front axle) = total required torque at the front axle wheel end * front and rear axle torque distribution ratio coefficient;

[0125] Required torque (rear axle) = total required torque at the rear axle wheel end * (1-front and rear axle torque distribution ratio coefficient);

[0126] When braking:

[0127] Required torque (front axle) = total required torque at the front axle wheel end * front and rear axle torque distribution ratio coefficient;

[0128] Required torque (rear axle) = total required torque at the rear axle wheel end * (1-front and rear axle torque distribution ratio coefficient).

[0129] The ASW system's monitoring scheme for the anti-slip control torque limiting function of ASW L1 is as follows:

[0130] (1) When both the front axle anti-skid control flag of ASW L1 and the front axle anti-skid control flag of ASW L2 are set, check whether the limit value of the front axle anti-skid control torque of ASW L1 is reasonable:

[0131] ① When the accelerator pedal opening is greater than 10% and the brake opening is less than 5%, which is the driving state, if the ASW L1 front axle anti-skid control torque limit value is higher than the front axle required torque, the ASW L1 front axle anti-skid control torque limit value is determined to be unreasonable.

[0132] ③ When the accelerator pedal opening is less than or equal to 5% and the brake opening is greater than or equal to 10%, it is the braking state. If the limit value of the front axle anti-skid control torque of ASW L1 is lower than the front axle required torque, it is determined that the limit value of the front axle anti-skid control torque of ASW L1 is unreasonable.

[0133] (2) When both the ASW L1 rear axle anti-skid control flag and the ASW L2 rear axle anti-skid control flag are set, check whether the limit value of the ASW L1 rear axle anti-skid control torque is reasonable:

[0134] ① When the accelerator pedal opening is greater than 10% and the brake opening is less than 5%, which is the driving state, if the limit value of the rear axle anti-skid control torque of ASW L1 is higher than the rear axle required torque, the limit value of the rear axle anti-skid control torque of ASW L1 is determined to be unreasonable.

[0135] ② When the accelerator pedal opening is less than or equal to 5% and the brake opening is greater than or equal to 10%, which is the braking state, if the limit value of the rear axle anti-skid control torque of ASW L1 is lower than the rear axle required torque, it is determined that the limit value of the rear axle anti-skid control torque of ASW L1 is unreasonable.

[0136] If it is detected that the limit of the ASW L1 front axle or rear axle anti-skid control torque is unreasonable, the ASW L1 front axle or rear axle anti-skid control torque should be reduced from the current value to the first target torque. Specifically, when the ASW L1 front axle anti-skid control torque is established, the AWD system should calculate the first target torque according to the wheel speed difference. The calculation formula is:

[0137] First target torque (front axle) = total required torque at the front axle wheel end * fact1 (based on the wheel speed difference table);

[0138] When the rear axle anti-slip control torque of ASW L1 is established, the AWD system should calculate the first target torque according to the wheel speed difference. The calculation formula is:

[0139] First target torque (rear axle) = total required torque at the rear axle wheel end * fact1 (based on the wheel speed difference table).

[0140] Among them, the greater the wheel speed difference, the smaller the fact1 value, and the value of fact1 is between 0.3-0.7.

[0141] Step 209: Determine the state of the first differential protection control flag according to the wheel speed data and the second threshold.

[0142] In this step, ASW L1 determines whether the differential protection is activated based on the wheel speed data and the second threshold. If the differential protection is activated, the first differential protection control flag is set; otherwise, the first differential protection control flag is reset. The first differential protection control flag is the front or rear axle differential protection control flag of ASW L1.

[0143] Specifically, when the difference between the left front wheel speed and the right front wheel speed (taking the absolute value) is higher than the second threshold, the front axle differential protection flag should be set; when the difference between the left rear wheel speed and the right rear wheel speed (taking the absolute value) is higher than the second threshold, the rear axle differential flag should be set.

[0144] The second threshold is based on a vehicle speed lookup table, as follows:

[0145] Vehicle speed: 0 20 40 80 100 120 kph

[0146] Second threshold: 0 40 55 90 90 90 kph

[0147] Therefore, when the vehicle speed is 20 kph, the second threshold is 40 kph; when the vehicle speed is 40 kph, the second threshold is 55 kph; if the vehicle speed is an intermediate value, the second threshold is determined by interpolation.

[0148] Step 210: Determine the state of the second differential protection control flag according to the wheel speed data and the third threshold.

[0149] In this step, ASW L2 determines whether differential protection is activated based on the wheel speed data and the third threshold. If the differential protection is activated, the second differential protection control flag is set; otherwise, the second differential protection control flag is reset. The second differential protection control flag is the front or rear axle differential protection control flag of ASW L2.

[0150] Specifically, when the speed difference between the left and right wheels of the front axle is greater than the third threshold, it is determined that the front axle triggers the differential protection to be turned on; when the speed difference between the left and right wheels of the rear axle is greater than the third threshold, it is determined that the rear axle triggers the differential protection to be turned on.

[0151] For example, the third threshold is 95 kph.

[0152] Step 211: When the second differential protection control flag is set and the first differential protection control flag is reset, gradually transition the differential protection control torque from the current value to the second target torque; or

[0153] When the first differential protection control flag is set, the second differential protection control flag is set, and the differential protection control torque is greater than the required torque, the differential protection control torque is gradually transitioned from the current value to the third target torque.

[0154] The first differential protection control flag is the front axle differential protection control flag of ASW L1, the second differential protection control flag is the front axle differential protection control flag of ASW L2, the differential protection control torque is the front axle differential protection control torque of ASW L1, the required torque is the total required torque of the front axle wheel end, and the second target torque is the second front axle target torque; or

[0155] The first differential protection control flag is the rear axle differential protection control flag of ASW L1, the second differential protection control flag is the rear axle differential protection control flag of ASW L2, the differential protection control torque is the rear axle differential protection control torque of ASW L1, the required torque is the total required torque of the rear axle wheel end, and the second target torque is the second rear axle target torque.

[0156] In the embodiment of the present invention, the differential protection control monitoring has two parts: one is the monitoring of the differential protection control flag of ASW L1, and the other is the monitoring of the differential protection control torque limiting function of ASW L1.

[0157] For example, Figure 6 FIG. 1 is a schematic diagram of the differential protection control monitoring logic according to an embodiment of the present invention, as shown in FIG. Figure 6 As shown in the figure, regarding the monitoring of the differential protection control flag, if ASW L2 detects that differential protection has occurred but the differential protection control flag of ASW L1 is not set, it is determined that the L1 differential protection control flag is faulty. ASW L2 should reduce the differential protection control torque to the second target torque.

[0158] In this embodiment of the present invention, if ASW L2 determines that the front axle differential protection is on, but ASW L1 determines that the front axle differential protection is not on, the AWD system should calculate the second target torque based on the wheel speed difference. The calculation formula is:

[0159] Second target torque (front axle) = total required torque at the front axle wheel end * fact2 (value: 0.7-0.9 according to the wheel speed difference table);

[0160] If ASW L2 determines that the rear axle differential protection is on, but ASW L1 determines that the rear axle differential protection is not on, the AWD system should calculate the second target torque according to the wheel speed difference. The calculation formula is:

[0161] Second target torque (rear axle) = total required torque at the rear axle wheel end * fact2 (value: 0.7-0.9 according to the wheel speed difference table).

[0162] Additionally, if ASW L1 front differential protection is enabled, L1 front differential protection torque limiting is required. For example, if the speed difference between the left and right front wheels exceeds 55 kph, the motor torque reduction is controlled to keep the speed difference around 55 kph. To account for hysteresis, the target speed difference is typically 45 kph.

[0163] Similarly, if ASW L1 rear differential protection is enabled, the L1 rear differential protection will limit torque. For example, if the speed difference between the left and right rear wheels exceeds 55 kph, the motor torque will be controlled to reduce the speed difference to around 55 kph. To account for hysteresis, the motor torque reduction is generally set to a target speed difference of 45 kph.

[0164] like Figure 6 As shown in the figure, regarding the monitoring of the differential protection control torque limit function, when ASW L1 and ASW L2 simultaneously detect that the differential protection is on (both differential protection flags are set), if the differential protection control torque of ASW L1 is still greater than the required torque, it is determined that the differential protection control torque limit of ASW L1 is not being executed. ASW L2 should reduce the differential protection control torque.

[0165] Specifically, when the front axle differential protection flag of ASW L1 and ASW L2 is set, the AWD system should detect whether the limit value of the front axle differential protection control torque of L1 is reasonable based on the driver's required torque (front axle) and the differential protection control torque of ASW L1 (front axle). The specific detection method is as follows:

[0166] ① When the accelerator pedal opening is greater than 10% and the brake opening is less than 5%, which is the driving state, if the ASW L1 front axle differential protection control torque limit value is higher than the front axle required torque, the front axle differential protection torque limit value is determined to be unreasonable.

[0167] ② When the accelerator pedal opening is less than or equal to 5% and the brake opening is greater than or equal to 10%, which is the braking state, if the limit value of the front axle differential protection control torque of ASW L1 is lower than the front axle required torque, it is determined that the limit value of the front axle differential protection control torque of ASW L1 is unreasonable.

[0168] Specifically, when the ASW L1 rear axle differential protection flag is set and the ASW L2 rear axle differential protection flag is set, the AWD system should detect whether the limit value of the ASW L1 rear axle differential protection control torque is reasonable based on the driver's required torque (rear axle) and the ASW L1 differential protection control torque (rear axle). The specific detection method is as follows:

[0169] ① When the accelerator pedal opening is greater than 10% and the brake opening is less than 5%, which is the driving state, if the limit value of the ASW L1 rear axle differential protection control torque is higher than the rear axle required torque, the limit value of the ASW L1 rear axle differential protection control torque is determined to be unreasonable.

[0170] ② When the accelerator pedal opening is less than or equal to 5% and the brake opening is greater than or equal to 10%, which is the braking state, if the limit value of the rear axle differential protection control torque of ASW L1 is lower than the rear axle required torque, it is determined that the limit value of the rear axle differential protection control torque of ASW L1 is unreasonable.

[0171] It is detected that the front axle differential protection control torque limit of ASW L1 is unreasonable. The front axle differential protection control torque should be reduced from the current value to the third target torque (front axle). The calculation formula of the third target torque (front axle) is:

[0172] Third target torque (front axle) = total required torque at the front axle wheel end * fact2 (value: 0.7-0.9 according to the wheel speed difference table); or

[0173] It is detected that the rear axle differential protection control torque limit of ASW L1 is unreasonable, and the rear axle differential protection control torque should be reduced from the current value to the third target torque (rear axle). Specifically, the calculation formula of the third target torque (rear axle) is:

[0174] The third target torque (rear axle) = the total required torque at the rear axle wheel end * fact2 (value: 0.7-0.9 according to the wheel speed difference table).

[0175] In addition, if both the first differential protection control flag and the second differential protection control flag are reset, ASWL2 should send the arbitration torque of ASW L1 to the PCU as the final torque determined by the AWD system.

[0176] The arbitration torque of ASW L1 is determined by the following method:

[0177] ① When the accelerator pedal opening is greater than 10% and the brake opening is less than 5%, it is in the driving state and the minimum value of the differential protection control torque of ASWL2 and the differential protection control torque of ASW L1 is taken.

[0178] ② When the accelerator pedal opening is less than or equal to 5% and the brake opening is greater than or equal to 10%, it is the braking state, and the maximum value of the differential protection control torque of ASW L2 and the differential protection control torque of ASW L1 is taken.

[0179] It should be understood that steps 206 to 208 and steps 209 to 211 may be performed simultaneously with steps 204 to 205 .

[0180] This embodiment of the present invention designs a PCU+AWD electric four-wheel drive functional safety architecture, which offers numerous benefits, including improved vehicle performance, enhanced system reliability, and optimized user experience. Its modular design facilitates system maintenance and upgrades. This embodiment of the present invention utilizes the PCU+AWD electric four-wheel drive functional safety architecture to design an electric functional safety and diagnostic control system to ensure driving safety.

[0181] Figure 7 A schematic diagram of a vehicle four-wheel drive function safety diagnosis and control device provided by an embodiment of the present invention is shown in FIG. Figure 7 As shown, the device includes: a processing module.

[0182] A processing module is used to obtain vehicle status data and a calculated value of a front and rear axle torque distribution ratio coefficient, wherein the calculated value is calculated based on the status data; if the calculated value is determined to be unreasonable, the value of the front and rear axle torque distribution ratio coefficient is set to a default value.

[0183] Optionally, the processing module is specifically configured to gradually transition the value of the front and rear axle torque distribution proportional coefficient from a current value to the default value.

[0184] Optionally, the processing module is specifically configured to determine that the calculated value is unreasonable if the calculated value is greater than 1 or less than 0; or

[0185] The calculated value is greater than or equal to 0 and less than or equal to 1. The change rate of the front and rear axle torque distribution ratio coefficient is determined based on the current value of the front and rear axle torque distribution ratio coefficient and the calculated value. The change rate is greater than a first threshold, and it is determined that the calculated value is unreasonable.

[0186] Optionally, the vehicle status data includes: steering wheel angle and wheel speed data;

[0187] After acquiring the status data of the electric four-wheel drive vehicle, the processing module is further configured to: determine the status of a first anti-skid flag according to the wheel speed data; determine the status of a second anti-skid flag according to the steering wheel angle, the wheel speed data, the accelerator pedal status, and the brake pedal status; when the second anti-skid flag is set and the first anti-skid flag is reset, gradually transition the anti-skid control torque from a current value to 0; or when the first anti-skid flag is set, the second anti-skid flag is set, and the anti-skid control torque is greater than the required torque, gradually transition the anti-skid control torque from a current value to a first target torque;

[0188] wherein the first anti-skid flag is a first front axle anti-skid flag, the second anti-skid flag is a second front axle anti-skid flag, the anti-skid control torque is a front axle anti-skid control torque, the required torque is a front axle required torque, and the first target torque is a first front axle target torque; or

[0189] The first anti-slip flag is the first rear axle anti-slip flag, the second anti-slip flag is the second rear axle anti-slip flag, the anti-slip control torque is the rear axle anti-slip control torque, the required torque is the rear axle required torque, and the first target torque is the first rear axle target torque.

[0190] Optionally, after acquiring the status data of the electric four-wheel drive vehicle, the processing module is further configured to: determine the status of a first differential protection control flag according to the wheel speed data and a second threshold; determine the status of a second differential protection control flag according to the wheel speed data and a third threshold; when the second differential protection control flag is set and the first differential protection control flag is reset, gradually transition the differential protection control torque from a current value to a second target torque; or when the first differential protection control flag and the second differential protection control flag are set and the differential protection control torque is greater than the required torque, gradually transition the differential protection control torque from a current value to a third target torque;

[0191] Wherein, the first differential protection control flag is a first front axle differential protection control flag, the second differential protection control flag is a second front axle differential protection control flag, the differential protection control torque is a front axle differential protection control torque, the required torque is a front axle required torque, and the second target torque is a second front axle target torque; or

[0192] The first differential protection control flag is the first rear axle differential protection control flag, the second differential protection control flag is the second rear axle differential protection control flag, the differential protection control torque is the rear axle differential protection control torque, the required torque is the rear axle required torque, and the second target torque is the second rear axle target torque.

[0193] Optionally, the vehicle status data further includes: motor data, shifter position, traffic conditions, high-definition maps, environmental information, and driving mode signals;

[0194] After acquiring the status data of the electric four-wheel drive vehicle, the processing module is further configured to: perform fault monitoring on data in the status data and mark faulty data as invalid.

[0195] Optionally, the vehicle status data further includes: an accelerator pedal signal, a brake pedal signal;

[0196] After acquiring the status data of the electric four-wheel drive vehicle, the processing module is further configured to: perform rationality monitoring on the accelerator pedal signal and the brake pedal signal to obtain the accelerator pedal status and the brake pedal status.

[0197] The vehicle four-wheel drive function safety diagnosis and control device provided by the embodiment of the present invention can be used to achieve the above Figures 1 to 6 The vehicle four-wheel drive function safety diagnosis method in the embodiment of the vehicle four-wheel drive function safety diagnosis method can be described in detail, and will not be repeated here.

[0198] Figure 8 This is a schematic diagram of the structure of an embodiment of the vehicle of this specification, as shown in FIG. Figure 8 As shown, the vehicle may include at least one processor; and at least one memory in communication with the processor, wherein the memory stores program instructions that can be executed by the processor, and the processor calls the program instructions to execute the instructions in this specification. Figures 1-6 The illustrated embodiment provides a vehicle four-wheel drive function safety diagnosis and control method.

[0199] Figure 8 A block diagram of an exemplary vehicle suitable for implementing embodiments of the present description is shown. Figure 8 The vehicle shown is only an example and should not limit the functionality and scope of use of the embodiments of this specification.

[0200] like Figure 8 As shown, the vehicle is represented as a general purpose computing device. Components of the vehicle may include, but are not limited to, one or more processors 21, memory 23, and a communication bus 24 connecting various system components (including the memory 23 and the processor 21).

[0201] The communication bus 24 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures. Examples of such architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnection (PCI) bus.

[0202] Vehicles typically include a variety of computer system readable media. These media can be any available media that can be accessed by the vehicle, including volatile and non-volatile media, removable and non-removable media.

[0203] The memory 23 may include computer-readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory. The vehicle may further include other removable or non-removable, volatile or non-volatile computer storage media. The memory 23 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of various embodiments of this specification.

[0204] A program / utility having a set (at least one) of program modules may be stored in memory 23. Such program modules include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. The program modules generally implement the functions and / or methods of the embodiments described herein.

[0205] The processor 21 executes various functional applications and data processing by running the programs stored in the memory 23, such as implementing the Figures 1-6 The illustrated embodiment provides a vehicle four-wheel drive function safety diagnosis and control method.

[0206] The embodiment of this specification provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, wherein the computer instructions enable the computer to execute the embodiment of this specification. Figures 1-6 The illustrated embodiment provides a vehicle four-wheel drive function safety diagnosis and control method.

[0207] The above-mentioned non-transitory computer-readable storage medium can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (Read Only Memory; hereinafter referred to as: ROM), an erasable programmable read-only memory (Erasable Programmable Read Only Memory; hereinafter referred to as: EPROM) or flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by an instruction execution system, device or device or used in combination with it.

[0208] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0209] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0210] Computer program code for performing the operations of this specification can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0211] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0212] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this specification. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0213] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout this specification, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0214] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of this specification includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of this specification belong.

[0215] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0216] It should be noted that the terminals involved in the embodiments of this specification may include but are not limited to personal computers (Personal Computer; hereinafter referred to as: PC), personal digital assistants (Personal Digital Assistant; hereinafter referred to as: PDA), wireless handheld devices, tablet computers (Tablet Computer), mobile phones, MP3 players, MP4 players, etc.

[0217] In the several embodiments provided in this specification, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some interface, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0218] In addition, the functional units in the various embodiments of this specification may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or hardware plus software functional units.

[0219] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute some steps of the method described in each embodiment of this specification. The aforementioned storage medium includes: a USB flash drive, a mobile hard disk, a read-only memory (hereinafter referred to as ROM), a random access memory (hereinafter referred to as RAM), a magnetic disk or an optical disk, and other media that can store program code.

[0220] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this specification should be included in the scope of protection of this specification.

Claims

1. A vehicle four-wheel drive function safety diagnosis and control method, characterized in that: The method comprises: Get vehicle status data; Acquire a calculated value of a torque distribution ratio coefficient of the front and rear axles, wherein the calculated value is calculated based on the state data; It is determined that the calculated value is unreasonable, and the value of the front and rear axle torque distribution ratio coefficient is set to a default value.

2. The method according to claim 1, characterized in that The step of setting the value of the front and rear axle torque distribution ratio coefficient to a default value includes: The value of the front and rear axle torque distribution ratio coefficient is gradually transitioned from the current value to the default value.

3. The method according to claim 1 or 2, characterized in that: Determining that the calculated value is unreasonable includes: The calculated value is greater than 1 or less than 0, and it is determined that the calculated value is unreasonable; or The calculated value is greater than or equal to 0 and less than or equal to 1. The change rate of the front and rear axle torque distribution ratio coefficient is determined based on the current value of the front and rear axle torque distribution ratio coefficient and the calculated value. If the change rate is greater than a first threshold, it is determined that the calculated value is unreasonable.

4. The method according to claim 1, characterized in that: The vehicle status data includes: steering wheel angle and wheel speed data; After obtaining the status data of the electric four-wheel drive vehicle, the method further includes: determining a state of a first anti-skid flag position according to the wheel speed data; Determine the state of the second anti-skid flag position according to the steering wheel angle, the wheel speed data, the accelerator pedal state and the brake pedal state; When the second anti-skid flag is set and the first anti-skid flag is reset, gradually transitioning the anti-skid control torque from a current value to 0; or When the first anti-skid flag is in position, the second anti-skid flag is in position and the anti-skid control torque is greater than the required torque, the anti-skid control torque is gradually transitioned from a current value to a first target torque.

5. The method according to claim 4, characterized in that After obtaining the status data of the electric four-wheel drive vehicle, the method further includes: Determining a state of a first differential protection control flag according to the wheel speed data and a second threshold; Determine the state of the second differential protection control flag according to the wheel speed data and a third threshold; When the second differential protection control flag is set and the first differential protection control flag is reset, gradually transitioning the differential protection control torque from the current value to the second target torque; or When the first differential protection control flag is set, the second differential protection control flag is set, and the differential protection control torque is greater than the required torque, the differential protection control torque is gradually transitioned from a current value to a third target torque.

6. The method according to claim 4, characterized in that The vehicle status data also includes: motor data, shifter position, traffic conditions, high-definition maps, environmental information and driving mode signals; After obtaining the status data of the electric four-wheel drive vehicle, the method further includes: Fault monitoring is performed on the data in the state data, and the faulty data is marked as invalid.

7. The method according to claim 4, characterized in that The vehicle status data also includes: an accelerator pedal signal and a brake pedal signal; After obtaining the status data of the electric four-wheel drive vehicle, the method further includes: The rationality of the accelerator pedal signal and the brake pedal signal is monitored to obtain the accelerator pedal state and the brake pedal state.

8. A vehicle comprising a memory and a processor, wherein the memory is used to store information including program instructions, and the processor is used to control the execution of the program instructions, characterized in that: When the program instructions are loaded and executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

9. A computer storage medium, characterized in that: The computer storage medium includes a stored computer program, wherein when the computer program is executed, the device where the storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

10. A computer program product, characterized in that The computer program product comprises a stored computer program, wherein when the computer program is executed, the device where the computer program product is located is controlled to execute the method according to any one of claims 1 to 7.

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