Vehicle control method and device, vehicle and storage medium

Abstract

The invention relates to a vehicle control method and device, a vehicle and a storage medium, and the method comprises the steps that a plurality of whole vehicle driving parameters of the vehicle under the current driving working condition are obtained; judging whether the wheel speed difference between the wheel speed of a left wheel and the wheel speed of a right wheel of the vehicle meets a preset control protection condition or not based on the multiple whole vehicle driving parameters; if the wheel speed difference meets the preset control protection condition, the actual torque limit value of the vehicle is determined based on the wheel speed difference, the multiple whole vehicle driving parameters and the bearing capacity of a differential mechanism and a universal joint of the vehicle under the current driving working condition, and the motor output upper limit of the vehicle is limited based on the torque limit value. Therefore, the technical problems that in the related technology, the actual stress of vehicle parts exceeds the bearing capacity under the special driving working condition due to the fact that the vehicle lacks the off-line power test and the power limit value under the special driving working condition, and large potential safety hazards exist are solved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle control, and particularly relates to a control method, device, vehicle and storage medium for a vehicle. Background Art

[0002] The constant velocity drive shaft assembly (composed of constant velocity universal joints, shaft rods, etc.), as a key component for torque transmission in the automotive power transmission system, that is, the pure electric drive motor provides torque to the reducer to achieve the function of speed reduction and torque increase, and then the torque is finally transmitted to the left and right wheels through the left and right constant velocity drive shaft assemblies to realize the vehicle driving function, so as to meet the torque and speed transmission under various complex and abusive working conditions such as various adhesion road surfaces, extreme turning, and wheel up and down jumping.

[0003] In the related art, the constant velocity drive shaft assembly in vehicle development generally passively receives the power output torque and the torque and speed transmission under various complex working conditions. There are no refined design requirements and verifications for the load-bearing capacity of power transmission components under extreme or abusive working conditions. However, the output torque of the drive motor under after-sales or in the case of being good at challenging extreme working conditions or misoperation working conditions will generate an excessive dynamic load impact coefficient, which is very likely to cause damage to the constant velocity drive shaft assembly, thereby causing the vehicle to lose torque transmission, and even causing driving safety. Due to the limited reliability test working condition conditions set for the vehicle, it is impossible to cover all after-sales working conditions and extreme abusive working conditions such as road surfaces. For example, when going straight on a high-adhesion road surface or in an extreme turning working condition, the front wheels are blocked by external obstacles, that is, the wheels cannot get out of trouble due to external force interference and are in a non-slip state. In this working condition, an excessive dynamic load impact torque will be generated, which may exceed the load-bearing capacity of the constant velocity universal joint at a large angle, thereby causing the fixed joint cage to break. Or when the single-wheel speed is too high on a high-low adhesion split road surface and rotates at a high speed for a long time in a straight line or at a large angle, it will generate frictional heat, thereby causing internal components to burn out and the sheath to be damaged, and there is an urgent need for improvement. Summary of the Invention

[0004] The present application provides a control method, device, vehicle and storage medium for a vehicle to solve the technical problem that in the related art, there is no pre-production power test and power limit value under special driving conditions for the vehicle, so that the actual force on vehicle components under special driving conditions exceeds the load-bearing capacity, and there are relatively large potential safety hazards.

[0005] An embodiment of the first aspect of the present application provides a control method for a vehicle, including the following steps: obtaining a plurality of vehicle driving parameters of the vehicle under the current driving condition; based on the plurality of vehicle driving parameters, determining whether the wheel speed difference between the left wheel speed and the right wheel speed of the vehicle meets a preset control protection condition; if the wheel speed difference meets the preset control protection condition, determining an actual torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle driving parameters, and the load-bearing capacities of the differential and the universal joint of the vehicle under the current driving condition, so as to limit the upper limit of the motor output of the vehicle based on the torque limit value.

[0006] Optionally, in an embodiment of the present application, the determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle driving parameters, and the load-bearing capacities of the left and right wheels of the vehicle under the current driving condition includes: extracting a corner value of the vehicle under the current driving condition from the plurality of vehicle driving parameters; when the wheel speed difference is greater than a first preset threshold and the corner value is zero, matching a corresponding first torque limit coefficient based on the wheel speed difference and the load-bearing capacity; calculating the actual torque limit value based on the first torque limit coefficient.

[0007] Optionally, in an embodiment of the present application, the determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle driving parameters, and the load-bearing capacities of the left and right wheels of the vehicle under the current driving condition includes: when the wheel speed difference is greater than the first preset threshold and the corner value is greater than zero, extracting the rotation direction and rotation amplitude of the vehicle's steering wheel from the plurality of vehicle driving parameters; matching a second torque limit coefficient based on the rotation direction, the rotation amplitude, the wheel speed difference, and the load-bearing capacity; calculating the actual torque limit value based on the second torque limit coefficient.

[0008] Optionally, in an embodiment of the present application, the determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle driving parameters, and the load-bearing capacities of the left and right wheels of the vehicle under the current driving condition includes: when the wheel speed difference is less than or equal to the first preset threshold and the corner value is zero, extracting the motor speed and the vehicle speed of the vehicle from the plurality of vehicle driving parameters; when the motor speed is zero and the vehicle speed is zero, determining a third torque limit coefficient based on the vehicle's overall parameters; calculating the actual torque limit value based on the third torque limit coefficient.

[0009] Optionally, in an embodiment of the present application, determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle running parameters, the left wheel bearing capacity and the right wheel bearing capacity of the vehicle under the current running condition includes: when the wheel speed difference is less than or equal to the first preset threshold and the steering angle value is greater than zero, matching a fourth torque limit coefficient based on the rotation direction, the rotation amplitude and the bearing capacity; calculating the actual torque limit value based on the fourth torque limit coefficient.

[0010] An embodiment of the second aspect of the present application provides a control device for a vehicle, including: an acquisition module, configured to acquire a plurality of vehicle running parameters of the vehicle under the current running condition; a judgment module, configured to judge whether the wheel speed difference between the left wheel speed and the right wheel speed of the vehicle meets a preset control protection condition based on the plurality of vehicle running parameters; a control module, configured to determine the actual torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle running parameters, and the bearing capacity of the differential and the universal joint of the vehicle under the current running condition when the wheel speed difference meets the preset control protection condition, so as to limit the upper limit of the motor output of the vehicle based on the torque limit value.

[0011] Optionally, in an embodiment of the present application, the control module includes: a first extraction unit, configured to extract the steering angle value of the vehicle under the current running condition from the plurality of vehicle running parameters; a first matching unit, configured to match a corresponding first torque limit coefficient based on the wheel speed difference and the bearing capacity when the wheel speed difference is greater than the first preset threshold and the steering angle value is zero; a first calculation unit, configured to calculate the actual torque limit value based on the first torque limit coefficient.

[0012] Optionally, in an embodiment of the present application, the control module includes: a second extraction unit, configured to extract the rotation direction and the rotation amplitude of the steering wheel of the vehicle from the plurality of vehicle running parameters when the wheel speed difference is greater than the first preset threshold and the steering angle value is greater than zero; a second matching unit, configured to match a second torque limit coefficient based on the rotation direction, the rotation amplitude, the wheel speed difference and the bearing capacity; a second calculation unit, configured to calculate the actual torque limit value based on the second torque limit coefficient.

[0013] Optionally, in an embodiment of the present application, the control module includes: a third extraction unit, configured to extract the motor speed and the vehicle speed of the vehicle from the multiple vehicle driving parameters when the wheel speed difference is less than or equal to the first preset threshold and the steering angle value is zero; a determination unit, configured to determine a third torque limit coefficient based on the vehicle parameters of the vehicle when the motor speed is zero and the vehicle speed is zero; and a third calculation unit, configured to calculate the actual torque limit based on the third torque limit coefficient.

[0014] Optionally, in an embodiment of the present application, the control module includes: a third matching unit, configured to match a fourth torque limit coefficient based on the rotation direction, the rotation amplitude, and the load capacity when the wheel speed difference is less than or equal to the first preset threshold and the steering angle value is greater than zero; and a fourth calculation unit, configured to calculate the actual torque limit based on the fourth torque limit coefficient.

[0015] An embodiment of the third aspect of the present application provides a vehicle, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the program to implement the vehicle control method as described in the above embodiment.

[0016] An embodiment of the fourth aspect of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores computer instructions for causing the computer to execute the vehicle control method as described in the above embodiment.

[0017] An embodiment of the fifth aspect of the present application provides a computer program product, including a computer program, which when executed, is used to implement the vehicle control method as described above.

[0018] The embodiments of the present application can determine whether torque limitation is required based on the wheel speed difference between the left and right wheel speeds of the vehicle according to multiple vehicle driving parameters under the current driving condition of the vehicle. When torque limitation is required, the actual torque limit of the vehicle is determined based on the wheel speed difference, multiple vehicle driving parameters, and the load capacity of the differential and universal joint of the vehicle under the current driving condition of the vehicle, so as to limit the upper limit of the motor output of the vehicle based on the torque limit, achieving that the left and right wheel speed differences are stably within a certain range in a short time under different working conditions, and the maximum torque value of the motor is limited within the specified value range according to each protection preset condition, improving the safety performance of the vehicle, reducing the design and development cost at the same time, realizing lightweight design, and playing a protective role for transmission components such as the differential. Thus, the technical problem in the related art that the vehicle lacks pre-production power tests and power limits under special driving conditions, resulting in the actual stress of vehicle components exceeding the load capacity under special driving conditions and posing a large safety hazard, is solved.

[0019] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above-mentioned and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of embodiments in conjunction with the accompanying drawings, in which:

[0021] Figure 1 Schematic diagram of the principle of the vehicle control method provided for an embodiment of the present application;

[0022] Figure 2 Flowchart of a vehicle control method provided according to an embodiment of the present application;

[0023] Figure 3 Boundary diagram of the differential (universal joint) provided for an embodiment of the present application;

[0024] Figure 4 Strength boundary diagram of the universal joint provided for an embodiment of the present application;

[0025] Figure 5 Flowchart of the vehicle control method provided for an embodiment of the present application;

[0026] Figure 6 Schematic structural diagram of a vehicle control device provided according to an embodiment of the present application

[0027] Figure 7 Schematic structural diagram of a vehicle provided according to an embodiment of the present application.

[0028] Wherein, 1 - TCS (Traction Control System) control module, 2 - VCU (Vehicle Control Unit) control module, 3 - MCU (Microcontroller Unit) control module, 4 - drive motor, 5 - reducer, 6a - left drive shaft assembly, 6b - right drive shaft assembly, 7a - left wheel, 7b - right wheel; 10 - vehicle control device, 100 - acquisition module, 200 - judgment module, 300 - control module; 701 - memory, 702 - processor, 703 - communication interface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0030] A control method, device, vehicle, and storage medium for a vehicle according to an embodiment of the present application will be described below with reference to the accompanying drawings. In view of the technical problem in the related art mentioned in the above background art that there is a lack of pre-offline power tests and power limits under special driving conditions for vehicles, resulting in the actual force on vehicle components exceeding the load-bearing capacity under special driving conditions and posing a significant safety hazard, the present application provides a control method for a vehicle. In this method, based on the wheel speed difference between the left and right wheel speeds of the vehicle, it can be determined whether torque limiting is required according to multiple vehicle driving parameters of the vehicle under the current driving condition. In the case where torque limiting is required, the actual torque limit of the vehicle is determined based on the wheel speed difference, multiple vehicle driving parameters, and the load-bearing capacity of the differential and universal joint of the vehicle under the current driving condition, so as to limit the upper limit of the motor output of the vehicle based on the torque limit, achieving that the left and right wheel speed differences are stabilized within a certain range in a short time under different working conditions, and the maximum torque value of the motor is limited within the specified value range according to each protection preset condition, improving the safety performance of the vehicle, reducing the design and development cost at the same time, realizing lightweight design, and playing a protective role for transmission components such as differentials. Thus, the technical problem in the related art that there is a lack of pre-offline power tests and power limits under special driving conditions for vehicles, resulting in the actual force on vehicle components exceeding the load-bearing capacity under special driving conditions and posing a significant safety hazard, is solved.

[0031] Since the external characteristics of pure electric drive motors can achieve the transmission of maximum torque at medium and low speeds, and the application of models with an increasingly small turning radius is becoming more and more common, the requirements for the large angle and load-bearing capacity of constant velocity universal joints are getting higher and higher, which puts more stringent requirements on the control of torque in the power transmission system, the structural strength of parts, and the design life, and will inevitably bring greater challenges and requirements to the performance of power transmission mechanical components. Therefore, whether the structural strength, torque under extreme misoperation conditions, and rotational speed of the constant velocity universal joint and assembly of pure electric vehicles meet the requirements has attracted much attention.

[0032] To ensure the driving safety of the vehicle, the control method of the vehicle according to the embodiment of the present application can limit the torque of the vehicle under special driving conditions to avoid overwork or damage to vehicle components.

[0033] First, the structure involved in the embodiment of the present application will be described. To achieve the above objectives, as Figure 1As shown in the figure, the structure involved in the embodiment of the present application may include: a TCS control module 1, a VCU control module 2, an MCU control module 3, a drive motor 4, a reducer 5, a left drive shaft assembly 6a, a right drive shaft assembly 6b, a left wheel 7a, and a right wheel 7b.

[0034] Among them, the VCU control module 2 can monitor in real time signals such as the accelerator pedal, EPS (electric power steering) corner signal (steering wheel corner), left and right wheel speed signals, brake pedal, vehicle speed signal, gear position, and motor speed to determine the driving direction of the vehicle and whether there is an excessive wheel speed difference between the left wheel 7a and the right wheel 7b. When the wheel speed difference between the left wheel 7a and the right wheel 7b exceeds the preset limit, corresponding torque limits are performed. The TCS control module 1 controls the wheel speed difference and protects it within the preset difference range. The MCU control module 3 makes limit protection for the maximum torque output of the drive motor 4 under different wheel speed differences and under the combined action of different steering angles or their combinations.

[0035] Based on the above structure, the embodiment of the present application can implement a vehicle control method.

[0036] Specifically, Figure 2 is a schematic flowchart of a vehicle control method provided by an embodiment of the present application.

[0037] As Figure 2 shown, the vehicle control method includes the following steps:

[0038] In step S201, multiple vehicle driving parameters under the current driving condition of the vehicle are obtained.

[0039] In the actual execution process, the embodiment of the present application can use the vehicle's VCU to obtain multiple vehicle driving parameters under the current driving condition, such as steering condition, straight driving condition, rough road driving condition, etc., such as real-time monitoring of signals such as the accelerator pedal, EPS corner signal (steering wheel corner), left and right wheel speed signals, brake pedal, vehicle speed signal, gear position, and motor speed, etc., to determine the driving direction of the vehicle and whether there is an excessive wheel speed difference between the left and right wheels based on multiple vehicle driving parameters, so as to implement torque limitation according to the wheel speed difference subsequently.

[0040] In step S202, based on multiple vehicle driving parameters, it is determined whether the wheel speed difference between the left wheel speed and the right wheel speed of the vehicle meets the preset control protection condition.

[0041] Furthermore, embodiments of the present application can determine the wheel speed difference and driving direction of the vehicle by real-time monitoring of vehicle driving parameters such as the accelerator pedal, EPS corner signal (steering wheel angle), left and right wheel speed signals, brake pedal, vehicle speed signal, gear position, motor speed, etc., and perform corresponding torque limit protection according to whether the wheel speed difference is too large. Among them, the preset control protection condition can be the wheel speed difference threshold, and the specific value can be set by those skilled in the art according to the actual situation, and no specific limitation is made here.

[0042] For example, when the left and right wheel speed difference exceeds a certain limit, embodiments of the present application can, according to a certain torque limit standard, control the wheel speed difference through TCS and protect it within a preset difference range, and the MCU limits and protects the maximum torque output of the motor under different wheel speed differences and different steering angles or their combinations.

[0043] In step S203, if the wheel speed difference meets the preset control protection condition, the actual torque limit of the vehicle is determined based on the wheel speed difference, multiple vehicle driving parameters, and the bearing capacities of the differential and universal joint of the vehicle under the current driving condition, so as to limit the upper limit of the motor output of the vehicle based on the torque limit.

[0044] As a possible implementation manner, embodiments of the present application can, in the case of determining that torque protection limitation is required, combine the wheel speed difference, multiple vehicle driving parameters, and the bearing capacities of the differential and universal joint of the vehicle under the current driving condition to obtain a torque upper limit that can ensure the normal driving of the vehicle but reduce the damage to the differential and universal joint.

[0045] Optionally, in an embodiment of the present application, determining the torque limit of the vehicle based on the wheel speed difference, multiple vehicle driving parameters, and the left and right wheel bearing capacities of the vehicle under the current driving condition includes: extracting the corner value of the vehicle under the current driving condition from multiple vehicle driving parameters; when the wheel speed difference is greater than the first preset threshold and the corner value is zero, matching the corresponding first torque limit coefficient based on the wheel speed difference and the bearing capacity; calculating the actual torque limit based on the first torque limit coefficient.

[0046] When the wheel speed difference is detected to be > X (X generally ranges from 60 km / h to 80 km / h and can be determined according to the product characteristics), and the steering angle = 0, the accelerator pedal is in the open state. The TCS control module reduces the torque of the ESC. After reaching the wheel speed difference threshold value, it will feedback to the motor MCU for control, and the wheel speed difference will be controlled within the target value range (such as 40 km / h to 60 km / h, which can be determined according to the product characteristics and calibration strategy) within 1 - 2 seconds to protect the internal components of the constant velocity universal joint or the connection part with the differential from high-speed friction ablation when the wheel speed difference between the left and right wheels is too large during straight driving (such as on a split high and low adhesion road surface, the left high adhesion road surface is stationary, and the right low adhesion road surface slips) during long-term operation. The torque limit corresponding to different speed differences is selected by interpolation method. For example: when the speed difference is 80 km / h, the Tmax torque limit value is selected. Where Tmax is the maximum torque at the motor output wheel end. Among them, the limitation of torque, that is, the torque coefficient can be as Figure 3 shown, obtained from the boundary diagram of the differential (universal joint). The boundary diagram varies according to the vehicle model structure. The relationship between the wheel speed difference and the torque limit value can be shown in Table 1 and Table 2. Among them, Table 1 is the first relationship table between the wheel speed difference and the torque limit value, and Table 2 is the corresponding first example table.

[0047] Table 1

[0048] Wheel speed difference 80 100 140 180 220 260 Torque limit value T <![CDATA[X1Tmax]]> <![CDATA[X2Tmax]]> <![CDATA[X2Tmax]]> <![CDATA[X4Tmax]]> <![CDATA[X5Tmax]]> <![CDATA[X6Tmax]]>

[0049] Table 2

[0050] Wheel speed difference 80 100 140 180 220 260 Torque limit value T Tmax 0.9Tmax 0.7Tmax 0.6Tmax 0.5Tmax 0.4Tmax

[0051] Optionally, in an embodiment of the present application, the torque limit value of the vehicle is determined based on the wheel speed difference, multiple vehicle driving parameters, the left wheel bearing capacity and the right wheel bearing capacity of the vehicle under the current driving condition, including: when the wheel speed difference is greater than the first preset threshold and the steering angle value is greater than zero, extracting the rotation direction and rotation amplitude of the vehicle's steering wheel from the multiple vehicle driving parameters; matching the second torque limit coefficient based on the rotation direction, rotation amplitude, wheel speed difference and bearing capacity; calculating the actual torque limit value based on the second torque limit coefficient.

[0052] When the wheel speed difference is detected to be > X (X generally takes values from 60 km / h to 80 km / h, which can be determined according to the product characteristics) and the steering angle > 0, the accelerator pedal is in the open state to prevent damage to the internal components of the constant velocity joint. The VCU control module monitors the rotational speed difference and steering angle signals in real time. While the TCS and MCU modules limit the rotational speed difference and the corresponding torque, the MCU limits the maximum torque of the motor at different steering angles. Finally, the minimum value min(T1, T2) of the torque limits corresponding to different combinations of rotational speed differences and steering angles is selected to protect the internal components of the constant velocity joint from high-speed friction ablation or torque overload causing fragmentation damage to the internal components of the constant velocity joint when the left and right wheels have too large a wheel speed difference during turning. The torque limits corresponding to different rotational speed differences or steering angles are selected using the interpolation method. For example, when the rotational speed difference is 80 km / h, the Tmax torque limit is selected; when the steering angle is 100% A, 0.3Tmax is selected. That is, when 80 km / h and a steering angle of 100% A are detected, the limited torque (the maximum torque at a single wheel end output by the motor) selects the smaller value of 0.3Tmax, where A is the total steering angle, ± is the steering of the steering wheel (positive for left turn and negative for right turn), and the percentage is the ratio of the current steering wheel angle to the total travel of the steering wheel. The load-carrying capacity in the turning situation can be as Figure 4 shown. Specifically, according to different specifications of the universal joint, the load-carrying capacity is also different.

[0053] The relationship between the wheel speed difference and the torque limit can be shown in Table 3 and Table 4. Among them, Table 3 is the second relationship table between the wheel speed difference and the torque limit, and Table 4 is the corresponding second example table.

[0054] Table 3

[0055] Rotational speed difference between left and right wheels 80 100 140 180 220 260 Steering angle ±100％A ±80％A ±60％A ±40％A ±20％A ±50％A Torque limit value T2 <![CDATA[Y1Tmax]]> <![CDATA[Y2Tmax]]> <![CDATA[Y3Tmax]]> <![CDATA[Y4Tmax]]> <![CDATA[Y4Tmax]]> <![CDATA[Y6Tmax]]>

[0056] Table 4

[0057] Rotational speed difference between left and right wheels 80 100 140 180 220 260 Steering angle ±100％A ±80％A ±60％A ±40％A ±20％A ±10％A Torque limit 0.30Tmax 0.45Tmax 0.6Tmax 0.75Tmax 0.75Tmax 0.75Tmax

[0058] Optionally, in an embodiment of the present application, the torque limit of the vehicle is determined based on the wheel speed difference, multiple vehicle driving parameters, the load-carrying capacity of the left wheel and the load-carrying capacity of the right wheel of the vehicle under the current driving condition, including: when the wheel speed difference is less than or equal to the first preset threshold and the steering angle value is zero, extracting the motor speed and the vehicle speed of the vehicle from the multiple vehicle driving parameters; when the motor speed is zero and the vehicle speed is zero, determining the third torque limit coefficient based on the vehicle parameters of the vehicle; and calculating the actual torque limit based on the third torque limit coefficient.

[0059] When the left - right wheel speed difference ≤ X (X generally takes values from 60 km / h to 80 km / h), the steering angle = 0, and the accelerator pedal is in the open state, when the motor speed is 0 km / h (the left - right wheel speeds are 0 rpm) and the vehicle speed is 0 km / h, the vehicle is in a stationary state, that is, the two front wheels are locked or jammed, and the maximum output torque of the motor is less than ZTmax (determined according to the product load and vehicle parameters, generally taking 0.7Tmax). The MCU control module restricts the motor current to meet the maximum torque limit protection. This protection strategy is mainly for the vehicle to output the maximum torque under extreme road conditions (such as when both front wheels are locked by external forces), and to protect the power transmission components from being damaged.

[0060] The relationship between the wheel speed difference and the torque limit can be as shown in Table 5. Among them, Table 5 is the relationship table of wheel speed difference, torque and torque limit.

[0061] Table 5

[0062] Rotational speeds of left and right wheels 0 km / h Vehicle speed 0 km / h Torque limit value T ZTmax

[0063] Optionally, in an embodiment of the present application, the torque limit of the vehicle is determined based on the wheel speed difference, multiple vehicle driving parameters, the left - wheel load - bearing capacity and the right - wheel load - bearing capacity of the vehicle under the current driving condition, including: when the wheel speed difference is less than or equal to the first preset threshold and the steering angle value is greater than zero, matching the fourth torque limit coefficient based on the rotation direction, rotation amplitude and load - bearing capacity; calculating the actual torque limit based on the fourth torque limit coefficient.

[0064] When it is detected that the wheel speed difference ≤ X (X generally takes values from 60 km / h to 80 km / h, which can be determined according to product characteristics) and the steering angle > 0, and the accelerator pedal is in the open state, the MCU control module restricts the current of the motor to meet the output of different maximum torques under different wheel speed differences and steering angles, so as to realize the protection of the torque input of the left - right equal - speed drive shafts when the vehicle is in extreme abuse and abnormal working conditions such as when the left - right wheels cannot rotate due to external forces or foreign objects and the ground adhesion is large enough during different turning angles and extreme turning angles, and prevent the damage of the internal components of the constant - velocity universal joint due to excessive torque output under extreme turning and road abuse conditions.

[0065] The relationship between the wheel speed difference and the torque limit can be as shown in Table 6 and Table 7. Among them, Table 6 is the third relationship table of wheel speed difference and torque limit, and Table 7 is the corresponding third example table.

[0066] Table 6

[0067] Steering angle ±100％A ±80％A ±60％A ±40％A ±20％A ±10％A Torque limit <![CDATA[Y1Tmax]]> <![CDATA[Y2Tmax]]> <![CDATA[Y3Tmax]]> <![CDATA[Y4Tmax]]> <![CDATA[Y4Tmax]]> <![CDATA[Y6Tmax]]>

[0068] Table 7

[0069] Steering angle ±100％A ±90％A ±80％A ±70％A ±60％A ±50％A Torque limit 0.30Tmax 0.35Tmax 0.45Tmax 0.55Tmax 0.60Tmax 0.75Tmax

[0070] Combined Figure 5 As shown, the working principle of the vehicle control method according to the embodiments of the present application will be described in detail with an example.

[0071] As Figure 5 shown, the embodiments of the present application can monitor the vehicle running parameters in real time through the VCU control module, calculate the wheel speed difference between the left and right wheels according to the vehicle running parameters, and determine the driving direction of the vehicle.

[0072] After the wheel speed difference exceeds a certain limit, the embodiments of the present application can match corresponding protection strategies (protection conditions A, B, C, D) for the vehicle according to the wheel speed difference and the turning angle. The TCS control module controls the wheel speed difference and protects it within a certain difference range. The MCU control module limits and protects the maximum torque output of the motor under different wheel speed differences and different steering angles or their combinations.

[0073] Among them, protection condition A: when it is detected that the wheel speed difference > X (X generally takes a value of 60 km / h - 80 km / h, which can be determined according to the product characteristics) and the turning angle = 0, and the accelerator pedal is in the open state, torque limitation is performed according to the protection strategy corresponding to protection condition A. The TCS control module reduces the torque of the ESC, and after reaching the wheel speed difference threshold value, it will feedback to the motor MCU for control, and control the wheel speed difference within the target value range (such as 40 km / h - 60 km / h, which can be determined according to the product characteristics and calibration strategy) within 1 - 2 s, so as to protect the internal components of the constant velocity universal joint or the connection part with the differential from high-speed friction ablation due to excessive wheel speed difference between the left and right wheels during straight running (such as on a split high and low adhesion road surface, the left high adhesion road surface is stationary, and the right low adhesion road surface slips) for a long time.

[0074] Protection condition B: when it is detected that the wheel speed difference > X (X generally takes a value of 60 km / h - 80 km / h, which can be determined according to the product characteristics) and the turning angle > 0, and the accelerator pedal is in the open state, to prevent damage to the internal components of the constant velocity universal joint, torque limitation is performed according to the protection strategy corresponding to protection condition B. The VCU control module monitors the rotational speed difference and turning angle signals in real time. While the TCS and MCU modules limit the rotational speed difference and the corresponding torque, the MCU limits the maximum torque of the motor under different turning angles. Finally, the minimum value min(T1, T2) of the torque limits corresponding to different combinations of rotational speed differences and different turning angles is selected, so as to protect the internal components of the constant velocity universal joint or the connection part with the differential from high-speed friction ablation or the internal components of the constant velocity universal joint from cracking and damage due to excessive torque when the wheel speed difference between the left and right wheels is too large during turning.

[0075] Protection condition C: When the left-right wheel speed difference is detected to be ≤ X (X generally takes a value of 60 km / h - 80 km / h) and the steering angle = 0, and the accelerator pedal is in the open state, when the motor speed is 0 km / h (the left and right wheel speeds are 0 rpm) and the vehicle speed is 0 km / h and the vehicle is in a stationary state, that is, the two front wheels are locked or jammed, torque limitation is carried out according to the protection strategy corresponding to protection condition C. The maximum output torque of the motor is less than ZTmax (determined according to the product load and vehicle parameters, generally taking 0.7Tmax). The MCU control module is used to limit the motor current to meet the maximum torque limitation protection. This protection strategy is mainly for the vehicle to output the maximum torque under extreme road conditions (such as when the front wheels are locked by the outside or external force), and to protect the power transmission components from being damaged.

[0076] Protection condition D: When the detected wheel speed difference is ≤ X (X generally takes a value of 60 km / h - 80 km / h, which can be determined according to the product characteristics) and the steering angle > 0, and the accelerator pedal is in the open state, torque limitation is carried out according to the protection strategy corresponding to protection condition D. The MCU control module limits the current of the motor to meet the output of different maximum torques under different wheel speed differences and steering angles, so as to realize the protection of the torque input of the left and right constant velocity drive shafts under extreme abuse working conditions such as when the left and right wheels cannot rotate due to external force or foreign object constraints and the ground adhesion is large enough at different turning angles and extreme turning angles of the vehicle, and to prevent the damage of the internal components of the constant velocity universal joint due to excessive torque output under extreme turning and road surface abuse working conditions.

[0077] In summary, the embodiments of the present application can detect signals such as the left and right wheel speed differences, ESP steering angle, accelerator pedal, gear position, brake pedal, motor speed, and vehicle speed in real time through the vehicle VCU control module, monitor whether the left and right wheel speed differences, EPS steering angle, motor speed, and vehicle speed meet the preset conditions, and perform execution control according to the protection strategies A, B, C, and D respectively according to different preset conditions. The protection conditions A, B, C, and D are set based on the working use characteristics of the constant velocity drive shaft universal joint (including the use conditions at the boundary connection part with the differential: the load conditions under different speed differences, the maximum allowable speed difference), and the load capacity (the maximum load curve under different included angles). The TCS control module controls the wheel speed difference according to different protection strategies, and the MCU limits the output torque of the motor, thereby realizing that the left and right wheel speed differences are stably within the preset range within a short time under different working conditions, and the maximum torque value of the motor is limited within the specified value according to each protection preset condition. This protection strategy solves the problems of damage to the constant velocity drive shaft universal joint components (including cage fragmentation, shaft rod fracture, star sleeve damage, sheath oil leakage, etc.) and ablation damage at the connection part with the differential of pure electric vehicles under special road surfaces and after-sales abuse working conditions (such as the front wheels being jammed by the outside at extreme turning), and at the same time reduces the design and development cost, realizes lightweight design, and plays a protective role for transmission components such as the differential.

[0078] According to the vehicle control method provided by the embodiments of the present application, based on multiple vehicle driving parameters under the current driving condition of the vehicle, it can be determined whether torque limitation is required according to the wheel speed difference between the left and right wheel speeds of the vehicle. When torque limitation is required, based on the wheel speed difference, multiple vehicle driving parameters, and the load-bearing capacity of the differential and universal joint of the vehicle under the current driving condition, the actual torque limitation of the vehicle is determined, so as to limit the upper limit of the motor output of the vehicle based on the torque limitation, achieving that the left and right wheel speed differences are stabilized within a certain range in a short time under different working conditions, and the maximum torque value of the motor is limited within the specified value according to each protection preset condition, improving the safety performance of the vehicle, reducing the design and development cost at the same time, realizing lightweight design, and playing a protective role for transmission components such as the differential. Thus, the technical problem in the related art that there is no pre-offline power test and power limitation under special driving conditions for the vehicle, resulting in the actual force on the vehicle components exceeding the load-bearing capacity under special driving conditions and posing a large safety hazard is solved.

[0079] Next, a vehicle control device according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0080] Figure 6 It is a block diagram of a vehicle control device according to an embodiment of the present application.

[0081] As Figure 6 shown, the vehicle control device 10 includes: an acquisition module 100, a judgment module 200, and a control module 300.

[0082] Specifically, the acquisition module 100 is configured to acquire multiple vehicle driving parameters of the vehicle under the current driving condition.

[0083] The judgment module 200 is configured to judge whether the wheel speed difference between the left and right wheel speeds of the vehicle meets a preset control protection condition based on multiple vehicle driving parameters.

[0084] The control module 300 is configured to determine the actual torque limitation of the vehicle based on the wheel speed difference, multiple vehicle driving parameters, and the load-bearing capacity of the differential and universal joint of the vehicle under the current driving condition when the wheel speed difference meets the preset control protection condition, so as to limit the upper limit of the motor output of the vehicle based on the torque limitation.

[0085] Optionally, in an embodiment of the present application, the control module 300 includes: a first extraction unit, a first matching unit, and a first calculation unit.

[0086] Among them, the first extraction unit is configured to extract the corner value of the vehicle under the current driving condition from multiple vehicle driving parameters.

[0087] The first matching unit is configured to match a corresponding first torque limit coefficient based on the wheel speed difference and the load capacity when the wheel speed difference is greater than a first preset threshold and the steering angle value is zero.

[0088] The first calculation unit is configured to calculate an actual torque limit based on the first torque limit coefficient.

[0089] Optionally, in an embodiment of the present application, the control module 300 includes: a second extraction unit, a second matching unit, and a second calculation unit.

[0090] Among them, the second extraction unit is configured to extract the rotational steering and rotational amplitude of the vehicle's steering wheel from multiple vehicle driving parameters when the wheel speed difference is greater than a first preset threshold and the steering angle value is greater than zero.

[0091] The second matching unit is configured to match a second torque limit coefficient based on the rotational direction, rotational amplitude, wheel speed difference, and load capacity.

[0092] The second calculation unit is configured to calculate an actual torque limit based on the second torque limit coefficient.

[0093] Optionally, in an embodiment of the present application, the control module 300 includes: a third extraction unit, a determination unit, and a third calculation unit.

[0094] Among them, the third extraction unit is configured to extract the motor speed and vehicle speed of the vehicle from multiple vehicle driving parameters when the wheel speed difference is less than or equal to a first preset threshold and the steering angle value is zero.

[0095] The determination unit is configured to determine a third torque limit coefficient based on the vehicle's overall vehicle parameters when the motor speed is zero and the vehicle speed is zero.

[0096] The third calculation unit is configured to calculate an actual torque limit based on the third torque limit coefficient.

[0097] Optionally, in an embodiment of the present application, the control module 300 includes: a third matching unit and a fourth calculation unit.

[0098] Among them, the third matching unit is configured to match a fourth torque limit coefficient based on the rotational direction, rotational amplitude, and load capacity when the wheel speed difference is less than or equal to a first preset threshold and the steering angle value is greater than zero.

[0099] The fourth calculation unit is configured to calculate an actual torque limit based on the fourth torque limit coefficient.

[0100] It should be noted that the foregoing explanation of the embodiment of the vehicle control method also applies to the vehicle control device of this embodiment, and will not be elaborated here.

[0101] The vehicle control device provided by the embodiments of the present application can determine whether torque limiting is required based on the wheel speed difference between the left and right wheel speeds of the vehicle according to multiple vehicle driving parameters under the current driving condition of the vehicle. In the case where torque limiting is required, the actual torque limit of the vehicle is determined based on the wheel speed difference, multiple vehicle driving parameters, and the load-bearing capacity of the differential and universal joint of the vehicle under the current driving condition of the vehicle, so as to limit the upper limit of the motor output of the vehicle based on the torque limit, achieving that the left and right wheel speed differences are stably within a certain range within a short time under different working conditions, and the maximum torque value of the motor is limited within the specified value according to each protection preset condition, improving the safety performance of the vehicle, reducing the design and development cost at the same time, realizing lightweight design, and playing a protective role for transmission components such as the differential. Thus, the technical problem in the related art that there is a lack of pre-production power tests and power limits for vehicles under special driving conditions, resulting in the actual stress of vehicle components exceeding the load-bearing capacity under special driving conditions and posing a large potential safety hazard is solved.

[0102] Figure 7 The structural schematic diagram of the vehicle provided by the embodiments of the present application. The vehicle may include:

[0103] A memory 701, a processor 702, and a computer program stored on the memory 701 and executable on the processor 702.

[0104] When the processor 702 executes the program, it implements the vehicle control method provided in the above embodiments.

[0105] Further, the vehicle further includes:

[0106] A communication interface 703 for communication between the memory 701 and the processor 702.

[0107] The memory 701 is used to store a computer program executable on the processor 702.

[0108] The memory 701 may include a high-speed RAM memory, and may also include non-volatile memory, such as at least one disk memory.

[0109] If the memory 701, the processor 702, and the communication interface 703 are implemented independently, the communication interface 703, the memory 701, and the processor 702 can be interconnected through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of simplicity of representation, Figure 7 only a thick line is used in Figure 7 , but it does not mean that there is only one bus or one type of bus.

[0110] Optionally, in a specific implementation, if the memory 701, the processor 702, and the communication interface 703 are integrated on a single chip, the memory 701, the processor 702, and the communication interface 703 can communicate with each other through an internal interface.

[0111] The processor 702 may be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0112] This embodiment also provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the control method of the vehicle as described above is implemented.

[0113] This application embodiment also provides a computer program product, including a computer program, and when the computer program is executed by a processor, the control method of the vehicle provided by the embodiments of the present invention is implemented.

[0114] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations 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 N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0115] In addition, 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 quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0116] Any process or method description represented in a flowchart or otherwise described herein may be understood to represent a module, segment, or portion of code including one or N executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of this application includes additional implementations, where the functions may be executed in a substantially simultaneous manner or in a reverse order according to the functions involved, rather than in the order shown or discussed, which should be understood by those skilled in the technical field to which the embodiments of this application belong.

[0117] The logic and / or steps represented in a flowchart or otherwise described herein, for example, may be considered a sequenced list of executable instructions for implementing a logical function, and may be specifically implemented in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection portion with one or N wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium may even be paper or other suitable medium on which the program can be printed, as the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpretation, or otherwise processing as appropriate, and then stored in a computer memory.

[0118] It should be understood that each part of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits with logic gate circuits for implementing logic functions on data signals, application specific integrated circuits with appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0119] Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing relevant hardware through a program. The said program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0120] In addition, in each embodiment of the present application, the functional units can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. When the above integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0121] The above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A control method for a vehicle, characterized in that, including the following steps: Obtain a plurality of vehicle running parameters of the vehicle under the current driving condition; Based on the plurality of vehicle running parameters, determine whether the wheel speed difference between the left wheel speed and the right wheel speed of the vehicle meets a preset control protection condition; If the wheel speed difference meets the preset control protection condition, determine the actual torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle running parameters, and the load-bearing capacity of the differential and universal joint of the vehicle under the current driving condition, so as to limit the upper limit of the motor output of the vehicle based on the torque limit value.

2. The method according to claim 1, wherein The determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle running parameters, and the load-bearing capacity of the left and right wheels of the vehicle under the current driving condition includes: Extract the steering angle value of the vehicle under the current driving condition from the plurality of vehicle running parameters; When the wheel speed difference is greater than a first preset threshold and the steering angle value is zero, match a corresponding first torque limit coefficient based on the wheel speed difference and the load-bearing capacity; Calculate the actual torque limit value based on the first torque limit coefficient.

3. The method according to claim 2, wherein The determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle running parameters, and the load-bearing capacity of the left and right wheels of the vehicle under the current driving condition includes: When the wheel speed difference is greater than the first preset threshold and the steering angle value is greater than zero, extract the rotation direction and rotation amplitude of the vehicle's steering wheel from the plurality of vehicle running parameters; Match a second torque limit coefficient based on the rotation direction, the rotation amplitude, the wheel speed difference, and the load-bearing capacity; Calculate the actual torque limit value based on the second torque limit coefficient.

4. The method according to claim 2, characterized in that, The determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle running parameters, and the load-bearing capacity of the left and right wheels of the vehicle under the current driving condition includes: When the wheel speed difference is less than or equal to the first preset threshold and the steering angle value is zero, extract the motor speed and vehicle speed of the vehicle from the plurality of vehicle running parameters; When the motor speed is zero and the vehicle speed is zero, determine a third torque limit coefficient based on the vehicle's overall parameters; Calculate the actual torque limit value based on the third torque limit coefficient.

5. The method according to claim 3, wherein The determining the torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle running parameters, and the load-bearing capacity of the left and right wheels of the vehicle under the current driving condition includes: When the wheel speed difference is less than or equal to the first preset threshold and the steering angle value is greater than zero, match a fourth torque limit coefficient based on the rotation direction, the rotation amplitude, and the load-bearing capacity; Calculate the actual torque limit value based on the fourth torque limit coefficient.

6. A control device for a vehicle, characterized in that, including: An acquisition module for acquiring a plurality of vehicle running parameters of the vehicle under the current driving condition; A judgment module for determining whether the wheel speed difference between the left wheel speed and the right wheel speed of the vehicle meets a preset control protection condition based on the plurality of vehicle running parameters; A control module, configured to determine an actual torque limit value of the vehicle based on the wheel speed difference, the plurality of vehicle driving parameters, and the load-bearing capacities of the differential and the universal joint of the vehicle under the current driving condition when the wheel speed difference meets the preset control protection condition, so as to limit the upper limit of the motor output of the vehicle based on the torque limit value.

7. The device according to claim 6, characterized in that, The control module includes: An extraction unit, configured to extract a corner value of the vehicle under the current driving condition from the plurality of vehicle driving parameters; A matching unit, configured to match a corresponding first torque limit coefficient based on the wheel speed difference and the load-bearing capacity when the wheel speed difference is greater than a first preset threshold and the corner value is zero; A calculation unit, configured to calculate the actual torque limit value based on the first torque limit coefficient.

8. A vehicle, characterized in that, It includes: A memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the program to implement the vehicle control method according to any one of claims 1-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to be used to implement the vehicle control method according to any one of claims 1-5.

10. A computer program product comprising a computer program, characterized in that, When the computer program is executed, it is used to implement the vehicle control method according to any one of claims 1-5.

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