A vehicle control method, device, storage medium, and vehicle
By calculating the upper and lower limits of torque transfer rate in real time, and combining driver needs and motor capabilities, drivability filtering is performed, which solves the smoothness problem during torque transfer in four-wheel drive vehicles and improves the driving stability and smoothness of the vehicle.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GAC AION NEW ENERGY AUTOMOBILE CO LTD
- Filing Date
- 2021-11-04
- Publication Date
- 2026-06-12
AI Technical Summary
In existing technologies, the torque transfer rate of four-wheel drive vehicles is not properly controlled during torque transfer, resulting in a decrease in vehicle ride comfort.
By calculating the upper and lower limits of the torque transfer rate in real time, the target torque distribution ratio is limited. Combined with the driver's needs and the motor's capabilities, drivability filtering is performed to obtain the actual torque distribution ratio.
It improves the vehicle's driving smoothness and ensures the stability and smoothness of the torque transfer process.
Smart Images
Figure CN116061700B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of automotive technology, specifically to a vehicle control method, device, storage medium, and vehicle. Background Technology
[0002] Compared to pure electric two-wheel drive vehicles, four-wheel drive vehicles use independent motors to drive the front and rear axles respectively. When the driver's required torque is determined, the vehicle can achieve independent front-wheel drive, independent rear-wheel drive, and four-wheel drive, making the power output more flexible and improving the vehicle's economy, stability, and passability.
[0003] However, to fully leverage the advantages of four-wheel drive vehicles, torque distribution and transfer are crucial. Torque distribution refers to the front and rear motors distributing torque according to a specific ratio (from 0 to 1) to meet the driver's torque demands; the calculation of this ratio must consider the influence of numerous factors. Torque transfer refers to the process of shifting from the current distribution ratio to the target distribution ratio; improper control of the torque transfer rate can significantly impact the overall vehicle performance.
[0004] Most existing technical solutions only focus on the control methods of four-wheel drive torque distribution, and no relevant solutions have yet been found for the problems existing in the torque transfer process. For example, when the total torque demanded by the driver remains constant, the torque transfer rate from the front axle to the rear axle is too fast, and the rear motor is in the commutation phase (the torque change slope is slower), the torque of the front motor has already decreased, while the torque of the rear motor has not made up for it in time. This will cause the torque output of the whole vehicle to decrease first and then increase, affecting the smoothness. Summary of the Invention
[0005] To address the aforementioned problems, this invention provides a vehicle control method that limits the target torque distribution ratio by calculating the upper limit and lower limit of the torque transfer rate in real time, thereby obtaining the actual torque distribution ratio and improving vehicle ride comfort.
[0006] On one hand, the present invention provides a vehicle control method, the vehicle control method comprising the following steps: obtaining the driver's required total torque based on accelerator pedal depth, vehicle speed, and driving mode; obtaining a target torque distribution ratio between the front motor and the rear motor based on the required total torque; performing drivability filtering on the front motor and the rear motor respectively to obtain a limit value for the torque change slope corresponding to the front motor and a limit value for the torque change slope corresponding to the rear motor; comparing the magnitudes of the limit values for the torque change slope of the front motor and the rear motor to obtain a minimum value of the limit values; obtaining an upper limit value and a lower limit value of the torque transfer rate based on the minimum value of the limit values and the required total torque; and limiting the target torque distribution ratio based on the upper limit value and the lower limit value of the torque transfer rate to obtain an actual torque distribution ratio.
[0007] In one embodiment, the step of obtaining the driver's required total torque based on accelerator pedal depth, vehicle speed, and driving mode includes the following steps:
[0008] The required total torque is obtained based on information such as accelerator pedal depth, vehicle speed, and driving mode.
[0009] The total torque change slope limit is obtained based on the accelerator pedal depth and the total required torque after the previous filtering, with the initial value used during the first start.
[0010] The total required torque is filtered based on the filtering parameters of the total torque change slope limit to obtain the filtered total required torque.
[0011] In one embodiment, the step of obtaining the target torque distribution ratio between the front motor and the rear motor based on the total required torque includes the following steps:
[0012] Based on the torque distribution control strategy, the target torque distribution ratio between the front motor and the rear motor is obtained through the filtered total required torque.
[0013] In one embodiment, the step of performing drivability filtering on the front motor and the rear motor respectively to obtain the limit value of the torque change slope corresponding to the front motor and the limit value of the torque change slope corresponding to the rear motor includes the following steps:
[0014] When the motor is in the torque commutation stage, the torque before slope filtering is obtained according to the total required torque and the target torque distribution ratio of the first motor, where the first motor is the front motor and / or the rear motor.
[0015] The torque before slope filtering is limited by the limit value of the previous torque change slope, with the initial value used during the first start-up, in order to obtain the torque after slope filtering.
[0016] The limit value of the torque change slope corresponding to the first motor is obtained based on the accelerator pedal depth, the slope-filtered torque, the motor speed, and the driving mode coefficient.
[0017] When the motor is in the non-torque commutation phase, the filtering parameters for the total torque change slope limit are obtained based on the accelerator pedal depth and the filtered total required torque.
[0018] Based on the filtering parameters of the total torque change slope limit and the target torque distribution ratio between the front motor and the rear motor, the limit values of the torque change slope corresponding to the front motor and the torque change slope corresponding to the rear motor are obtained.
[0019] In one embodiment, the step of obtaining the upper limit value and the lower limit value of the torque transfer rate based on the minimum value of the limit value and the total required torque includes the following steps:
[0020] The upper limit and lower limit of the torque transfer rate are determined based on the minimum value between the limit value of the torque change slope corresponding to the front motor and the limit value of the torque change slope corresponding to the rear motor.
[0021] In one embodiment, the step of limiting the target torque distribution ratio based on the upper limit and the lower limit of the torque transfer rate to obtain the actual torque distribution ratio includes the following steps:
[0022] The maximum value of the actual torque distribution ratio when it changes upward shall not exceed the upper limit of the torque transfer rate, and the minimum value of the actual torque distribution ratio when it changes downward shall not be lower than the lower limit of the torque transfer rate.
[0023] This invention proposes a vehicle control method, device, storage medium, and vehicle. Using the filtered total torque demand of the driver and the limit values of the torque change slope of the front and rear motors, the torque transfer rate is calculated in real time. The target distribution ratio calculated by the torque distribution strategy is restricted to obtain the actual executable torque distribution ratio, thereby improving the smoothness of the vehicle. Attached Figure Description
[0024] Figure 1 This is a flowchart of a vehicle control method according to an embodiment of the present invention;
[0025] Figure 2 As an embodiment of the present invention Figure 1The detailed flowchart of step S31 is shown below;
[0026] Figure 3 As in one embodiment of the present invention Figure 1 The detailed flowchart of step S31 is shown below;
[0027] Figure 4 This is the structure of the vehicle control device in the present invention. Detailed Implementation
[0028] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of preferred embodiments with reference to the accompanying drawings. Through the description of the specific embodiments, a more in-depth and specific understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the present invention.
[0029] Figure 1 , 2 This is a flowchart of the vehicle control method in this invention. Figure 1 The vehicle control method shown can be applied to, but is not limited to, a vehicle control device.
[0030] like Figure 1 As shown, the vehicle control method includes the following steps:
[0031] Step S11: Obtain the driver's required total torque based on accelerator pedal depth, vehicle speed, and driving mode;
[0032] Step S12: Obtain the target torque distribution ratio between the front motor and the rear motor based on the total required torque;
[0033] Step S13: Perform drivability filtering on the front motor and / or rear motor to obtain the limit value of the torque change slope corresponding to the front motor and the limit value of the torque change slope corresponding to the rear motor.
[0034] Step S14: Compare the limit values of the torque change slope of the front motor and the torque change slope of the rear motor to obtain the minimum limit value;
[0035] Step S15: Based on the minimum limit value and the total required torque, obtain the upper limit value and the lower limit value of the torque transfer rate;
[0036] Step S16: Limit the target torque distribution ratio according to the upper limit and lower limit of the torque transfer rate to obtain the actual torque distribution ratio.
[0037] In one embodiment, considering the capacity limitations of the battery and motor, the total demand torque is also filtered to obtain a filtered total demand torque TqReq that is closer to the sum of the torques executed by the front and rear motors and can be used for torque distribution. fild As shown in the formula below, where TqReq represents the total required torque and Perc pedal The accelerator pedal depth is indicated by V, vehicle speed by V, and driving mode by DrvMode.
[0038] TqReq fild =Filtered{TqReq(Perc pedal ,V,DrvMode)}
[0039] In one embodiment, step S12, the step of obtaining the target torque distribution ratio between the front motor and the rear motor based on the total required torque, includes: filtering the total required torque according to the filtering parameters of the total torque change slope limit to obtain the filtered total required torque; and obtaining the target torque distribution ratio between the front motor and the rear motor based on the torque distribution control strategy using the filtered total required torque. Specifically, the filtering parameters of the total torque change slope limit can be obtained by looking up a table based on the current accelerator pedal depth and the torque of the previously filtered total required torque. The first filtered total required torque can be, but is not limited to, a set initial value.
[0040] like Figure 2 As shown, in one embodiment, step S13: performing drivability filtering on the front motor and / or rear motor to obtain a limit value for the torque change slope corresponding to the front motor and a limit value for the torque change slope corresponding to the rear motor, including:
[0041] Step S131a: When the motor is in the torque commutation stage, the torque before slope filtering is obtained according to the total required torque and the target torque distribution ratio of the first motor. The first motor is the front motor and / or the rear motor. The torque before slope filtering is limited by the limit value of the previous torque change slope to obtain the torque after slope filtering.
[0042] Step S132a: Obtain the limit value of the torque change slope corresponding to the first motor based on the accelerator pedal depth, the torque after slope filtering, the motor speed, and the driving mode coefficient.
[0043] like Figure 3 As shown, in one embodiment, step S13: performing drivability filtering on the front motor and / or rear motor to obtain a limit value for the torque change slope corresponding to the front motor and a limit value for the torque change slope corresponding to the rear motor, including:
[0044] Step S131b: When the motor is in the non-torque commutation stage, obtain the filtering parameters of the total torque change slope limit based on the accelerator pedal depth and the filtered total required torque;
[0045] Step S132b: Based on the filtering parameters of the total torque change slope limit and the target torque distribution ratio between the front motor and the rear motor, obtain the limit values of the torque change slope corresponding to the front motor and the torque change slope corresponding to the rear motor.
[0046] Specifically, in one embodiment, to ensure vehicle smoothness, both the front and rear motors are differentiated into torque commutation and non-torque commutation phases, and drivability filtering is applied separately for each. The torque change slope limit value of the front motor is set by GrdtTq. front It indicates that the accelerator pedal depth is determined by Perc. acpedal The torque after slope filtering of the front motor is represented by Tq. front The motor speed of the front motor is represented by N. front The driving mode coefficient corresponding to the front motor is indicated by Fac. front This indicates that the filtering parameters for the total torque change slope limit are determined by GrdtTq. sum This indicates that the target torque distribution ratio is determined by Perc. tqsplttar This indicates that the torque commutation range of the front motor is Tq1 to Tq2, and the torque commutation range of the rear motor is Tq3 to Tq4. Please refer to the front motor for the variable symbols for the rear motor, except that the subscript for all variables in the rear motor is "rear". The specific calculation formula is as follows:
[0047]
[0048]
[0049] In one embodiment, the calculation of the upper limit of the torque transfer rate in step S15 is carried out in order to avoid exceeding the value of the front motor GrdtTq. front The slope of the torque change of the rear motor (GrdtTq) rear To further ensure vehicle smoothness, the smaller of the torque change slopes of the front motor and the rear motor is first compared and calculated in Nm / s. This smaller value is then divided by the filtered total required torque TqReq. fild Then multiply by 100%, and finally convert the unit to % / s. Additionally, the upper limit of the torque transfer rate is TqTransRate. upper and the lower limit of torque transfer rate TqTransRate lower For opposite signs, the formula is as follows:
[0050]
[0051] TqTransRate lower =-TqTransRate upper
[0052] In other embodiments, step S15: obtaining the upper limit and lower limit of the torque transfer rate based on the minimum limit value and the total required torque includes:
[0053] Stability factors are obtained based on vehicle speed and driving mode;
[0054] Find the minimum value between the stability factor and the minimum limit value to determine the upper limit and lower limit of the torque transfer rate.
[0055] The step of obtaining the stability factor based on vehicle speed and driving mode may include, but is not limited to: obtaining a first adjustment coefficient based on vehicle speed and driving mode; obtaining a second adjustment coefficient under different torque distribution states; and obtaining the stability factor based on the product of the first adjustment coefficient and the second adjustment coefficient.
[0056] Specifically, but not limited to, a two-dimensional coefficient table can be created based on vehicle speed V and driving mode DrvMode to obtain the first adjustment coefficient, and then a second adjustment coefficient Fac can be distinguished between different torque distribution adjustment states. TqAdjMode Therefore, based on the first adjustment coefficient and the second adjustment coefficient Fac TqAdjMode The product of the product yields the stability factor Fac stability The stability factor Fac is obtained. stability The specific calculation formula is as follows, where the second adjustment coefficient can be, for example, steering, ESP intervention, etc.:
[0057] Fac stability =Fac TqAdjMode ×Fac(V,DrvMode)
[0058] Then, obtain the stability factor Fac. stability The minimum value between the limit value and the minimum value is used to determine the upper limit of the torque transfer rate, as shown in the following formula:
[0059]
[0060] TqTransRate lower =-TqTransRate upper
[0061] In one embodiment, step S16: limiting the target torque distribution ratio according to the upper limit and lower limit of the torque transfer rate to obtain the actual torque distribution ratio includes: controlling the maximum value of the actual torque distribution ratio when it changes upward to not exceed the upper limit of the torque transfer rate, and controlling the minimum value of the actual torque distribution ratio when it changes downward to not be lower than the lower limit of the torque transfer rate.
[0062] Figure 4 This is a structural diagram of the vehicle control device in this invention. Figure 4 As shown, the vehicle control device 4 includes a memory 41 and a processor 42. The memory stores a computer program, and the processor executes the computer program to implement the steps of the vehicle control method described above.
[0063] The present invention also provides a storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described vehicle control method.
[0064] The present invention also provides a vehicle including the vehicle control device described above.
[0065] The vehicle control method, vehicle control device, storage medium, and vehicle of the present invention can perform drivability filtering on the front motor and / or the rear motor to obtain a limit value for the torque change slope corresponding to the front motor and a limit value for the torque change slope corresponding to the rear motor, thereby limiting the target torque distribution ratio to obtain the actual torque distribution ratio, which can improve the smoothness of the vehicle.
[0066] This invention can perform drivability filtering on the front motor and / or rear motor to obtain limit values for the torque change slope corresponding to the front motor and the torque change slope corresponding to the rear motor, thereby limiting the target torque distribution ratio to obtain the actual torque distribution ratio and improving vehicle smoothness. The above description is merely a preferred embodiment of the invention and is not intended to limit the invention in any way. Although the invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the invention, without departing from the scope of the invention, still fall within the scope of the invention.
Claims
1. A vehicle control method, characterized in that, The method includes: The total torque required by the driver is obtained based on the accelerator pedal depth, vehicle speed, and driving mode. The target torque distribution ratio between the front motor and the rear motor is obtained based on the total required torque. The front motor and / or the rear motor are subjected to drivability filtering to obtain a limit value for the torque change slope corresponding to the front motor and a limit value for the torque change slope corresponding to the rear motor; The minimum value of the limit value is obtained by comparing the limit value of the torque change slope of the front motor and the limit value of the torque change slope of the rear motor. Based on the minimum value of the limit and the total required torque, obtain the upper limit value of the torque transfer rate and the lower limit value of the torque transfer rate; The target torque distribution ratio is limited based on the upper limit and the lower limit of the torque transfer rate to obtain the actual torque distribution ratio. The step of obtaining the upper limit and lower limit of the torque transfer rate based on the minimum value of the limit and the total required torque includes: A stability factor is obtained based on the vehicle speed and the driving mode; The minimum value between the stability factor and the minimum value of the limit value is obtained to determine the upper limit value and the lower limit value of the torque transfer rate.
2. The vehicle control method as described in claim 1, characterized in that, The steps for obtaining the target torque distribution ratio between the front and rear motors based on the total required torque include: The total required torque is filtered based on the filtering parameters of the total torque change slope limit to obtain the filtered total required torque. Based on the torque distribution control strategy, the target torque distribution ratio between the front motor and the rear motor is obtained through the filtered total required torque.
3. The vehicle control method as described in claim 1, characterized in that, The step of performing drivability filtering on the front motor and / or the rear motor to obtain a limit value for the torque change slope corresponding to the front motor and a limit value for the torque change slope corresponding to the rear motor includes: When the front motor and / or the rear motor are in the torque commutation stage, the torque before slope filtering is obtained according to the total required torque and the target torque distribution ratio of the front motor and / or the rear motor. The torque before slope filtering is limited by the limit value of the previous torque change slope to obtain the torque after slope filtering. The limit value of the torque change slope corresponding to the front motor and / or the rear motor is obtained based on the accelerator pedal depth, the slope-filtered torque, the speed of the front motor and / or the rear motor, and the driving mode coefficient.
4. The vehicle control method as described in claim 1 or 3, characterized in that, The step of performing drivability filtering on the front motor and / or the rear motor to obtain a limit value for the torque change slope corresponding to the front motor and a limit value for the torque change slope corresponding to the rear motor includes: When the front motor and / or the rear motor are in the non-torque commutation phase, filter parameters for the total torque change slope limit are obtained based on the accelerator pedal depth and the filtered total required torque. Based on the filtering parameters of the total torque change slope limit and the target torque distribution ratio between the front motor and the rear motor, the limit values of the torque change slope corresponding to the front motor and the torque change slope corresponding to the rear motor are obtained.
5. The vehicle control method as described in claim 1, characterized in that, The steps for obtaining the stability factor based on the vehicle speed and the driving mode include: A first adjustment coefficient is obtained based on the vehicle speed and the driving mode; Obtain the second adjustment coefficient under different torque distribution states; The stability factor is obtained by multiplying the first adjustment coefficient and the second adjustment coefficient.
6. The vehicle control method as described in claim 1, characterized in that, The method for limiting the target torque distribution ratio based on the upper limit and the lower limit of the torque transfer rate to obtain the actual torque distribution ratio includes: The maximum value of the actual torque distribution ratio when it changes upward is controlled not to exceed the upper limit of the torque transfer rate, and the minimum value of the actual torque distribution ratio when it changes downward is controlled not to be lower than the lower limit of the torque transfer rate.
7. A vehicle control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the vehicle control method as described in any one of claims 1 to 6.
8. A storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the vehicle control method as described in any one of claims 1 to 6.
9. A vehicle, characterized in that, Includes the vehicle control device as described in claim 7.