CN-121989706-A - Intelligent torque distribution control method and system for pure electric four-wheel drive automobile

CN121989706ACN 121989706 ACN121989706 ACN 121989706ACN-121989706-A

Abstract

The invention provides an intelligent torque distribution control method and system for a pure electric four-wheel drive vehicle, and belongs to the technical field of whole vehicle energy management of the pure electric four-wheel drive vehicle. The method comprises the steps of collecting running state parameters, battery parameters and environment parameters of an electric drive system of a vehicle in real time, calculating wheel end required torque under the current working condition based on the running state parameters, the battery parameters and the environment parameters of the electric drive system, obtaining candidate torque distribution coefficients based on the current speed and the wheel end required torque, calculating total power loss generated by the electric drive system after the electric drive system distributes torque according to the coefficients aiming at the candidate torque distribution coefficients, selecting the coefficient with the minimum total power loss from the candidate torque distribution coefficients as an optimal torque distribution coefficient under the current working condition, and controlling torque output of a front motor and a rear motor based on the optimal torque distribution coefficient. The invention can effectively reduce the power consumption, improve the endurance mileage of the vehicle and solve the problem that the motor control and the actual high-efficiency area deviate in the prior art.

Inventors

LIU YAWEI
LONG JINSHI
LEI ZHI
CAO XINYUN
YANG LIANG

Assignees

奇瑞汽车股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260109

Claims (10)

1. The intelligent torque distribution control method for the pure electric four-wheel drive automobile is characterized by comprising the following steps of: collecting running state parameters, battery parameters and environmental parameters of an electric drive system of a vehicle in real time; Calculating the wheel end required torque under the current working condition based on the running state parameters, the battery parameters and the environmental parameters of the electric drive system; based on the current vehicle speed and the wheel end required torque, acquiring a plurality of candidate torque distribution coefficients; Calculating total power loss generated by the front and rear electric drive systems after distributing torque according to the coefficient aiming at each candidate torque distribution coefficient; And controlling the torque output of the front motor and the rear motor based on the optimal torque distribution coefficient.
2. The intelligent torque distribution control method for the pure electric four-wheel-drive automobile according to claim 1, wherein the running state parameters comprise ambient temperature, speed, accelerator and brake data, the battery parameters comprise battery SOC, battery voltage, battery current, maximum allowable battery charge and discharge power and battery temperature data, and the ambient parameters of the electric drive system comprise cooling water temperature, electric drive controller temperature, electric drive stator and rotor temperature, oil temperature, electric drive rotating speed, electric drive torque and electric drive peak torque data.
3. The intelligent torque distribution control method for a pure electric four-wheel-drive vehicle according to claim 1, wherein calculating the wheel end required torque under the current working condition based on the running state parameter, the battery parameter and the environmental parameter of the electric drive system comprises: the vehicle speed, the accelerator, the brake, the maximum allowable charge and discharge power of the battery and the electric drive peak torque are analyzed to obtain the wheel end required torque at the moment, and the vehicle speed-wheel end required torque-torque distribution coefficient data set is calibrated through a preset torque distribution control strategy based on the current vehicle speed and the current wheel end required torque.
4. The intelligent torque distribution control method for a pure electric four-wheel-drive vehicle according to claim 1, wherein obtaining a plurality of candidate torque distribution coefficients based on a current vehicle speed and the wheel end required torque comprises: based on the current real-time vehicle speed and the wheel end required torque, a torque distribution coefficient data set is obtained by calling a preset torque distribution control strategy, and each discretized value in the torque distribution coefficient data set is a candidate torque distribution coefficient; And extracting all discretized values from the torque distribution coefficient data set to form a plurality of candidate torque distribution coefficients, wherein each candidate torque distribution coefficient corresponds to a front motor torque distribution proportion and a rear motor torque distribution proportion and is used for screening the optimal torque distribution coefficient.
5. The intelligent torque distribution control method for a pure electric four-wheel drive vehicle according to claim 1, wherein for each candidate torque distribution coefficient, calculating total power loss generated after the front and rear electric drive systems distribute torque according to the coefficient comprises: Aiming at each candidate torque distribution coefficient, respectively calculating target distribution torques of the front and rear electric drive systems under the candidate coefficient according to the currently calculated wheel end required torque; Receiving a target distribution torque command sent by a vehicle controller, and controlling a front electric drive system and a rear electric drive system to operate according to the target distribution torque; Judging the current running condition of the vehicle based on the running state parameters, the battery parameters and the environmental parameters of the electric drive system, which are acquired in real time; And respectively calculating the power loss of the front and rear electric drive systems of the vehicle under different vehicle driving conditions to obtain the total power loss of the front and rear electric drive systems corresponding to the current candidate torque distribution coefficient.
6. The intelligent torque distribution control method for a pure electric four-wheel drive vehicle according to claim 1, wherein a coefficient minimizing total power loss is selected as an optimal torque distribution coefficient under a current working condition from the plurality of candidate torque distribution coefficients, further comprising: And obtaining optimal torque distribution coefficients of the vehicle under different vehicle speeds and different wheel end torque demands, dividing the vehicle speeds and the wheel end torque demands according to specific intervals, and fitting and converging the optimal torque distribution coefficients according to the vehicle speed intervals and the wheel end torque demand intervals to obtain a vehicle speed-wheel end torque demand-optimal torque distribution coefficient table.
7. The intelligent torque distribution control method for a pure electric four-wheel drive vehicle according to claim 1, wherein controlling torque output of front and rear motors based on the optimal torque distribution coefficient comprises: and according to the environment information of the front and rear electric drives and the vehicle speed-wheel end required torque-optimal torque distribution coefficient table, learning and training a preset torque distribution control model, after training, outputting the vehicle speed-wheel end required torque-optimal torque distribution coefficient table based on the motor environment information by the torque distribution control model, and controlling the torque distribution output of the pure electric four-wheel drive vehicle under different motor environments according to the vehicle speed-wheel end required torque-optimal torque distribution coefficient table.
8. An intelligent torque distribution control system for a pure electric four-wheel drive automobile, which is characterized by comprising: the data acquisition module is configured to acquire running state parameters of the vehicle, battery parameters and environmental parameters of the electric drive system in real time; The wheel end required torque calculation module is configured to calculate wheel end required torque under the current working condition based on the running state parameters, the battery parameters and the environmental parameters of the electric drive system; a torque distribution coefficient acquisition module configured to acquire a plurality of candidate torque distribution coefficients based on a current vehicle speed and the wheel end required torque; The optimal torque distribution coefficient calculation module is configured to calculate total power loss generated after the front and rear electric drive systems distribute torque according to each candidate torque distribution coefficient; selecting a coefficient which minimizes the total power loss from the plurality of candidate torque distribution coefficients as an optimal torque distribution coefficient under the current working condition; And a torque output control module configured to control torque outputs of the front and rear motors based on the optimal torque distribution coefficient.
9. A computer-readable storage medium having a program stored thereon, which when executed by a processor, implements the steps of a method for intelligent torque distribution control of a four-wheel drive electric vehicle according to any one of claims 1 to 7.
10. An electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of a method for intelligent torque distribution control of a four-wheel drive electric vehicle as claimed in any one of claims 1 to 7.

Description

Intelligent torque distribution control method and system for pure electric four-wheel drive automobile Technical Field The invention belongs to the technical field of whole vehicle energy management of a pure electric four-wheel drive vehicle, and particularly relates to an intelligent torque distribution control method and system of a pure electric four-wheel drive vehicle. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. With the increasing severity of global energy crisis and environmental pollution problems, the development of new energy automobiles has become a major direction of transformation in the automobile industry. The pure electric vehicle is widely accepted in the market by virtue of the advantages of zero emission, high energy efficiency, low noise and the like. In the pure electric vehicles, four-wheel drive vehicles are favored by consumers because of their superior traction performance, stability and trafficability. The torque distribution control of the existing pure electric vehicle type mainly makes a fixing strategy based on normal-temperature rack test data of a motor. The technical staff obtains an efficiency map (efficiency characteristic curve), a dragging map (dragging loss characteristic) and a 0Nm loss map (energy loss without torque output) of the front motor and the rear motor through a bench test, and then, in combination with the basic requirements of the vehicle dynamics and the driving stability, a group of fixed front motor and rear motor torque distribution coefficients are calibrated in advance and used for guiding the power distribution in the whole vehicle driving process. However, in the actual running process of the vehicle, the running state of the motor is influenced by multiple dynamic factors, so that the existing strategy is seriously disjointed from the actual working condition. For example, the motor is affected by bus voltage, ambient temperature, water temperature, stator and rotor temperature, oil temperature and the like, the efficiency and high efficiency area is offset, and drag loss at low temperature is increased, so that the control of the motor operating point in the prior art is deviated from the actual comprehensive operation and high efficiency area of the motor. The existing torque distribution control method of the pure electric four-wheel drive automobile cannot dynamically adapt to environmental changes, voltage fluctuation and multi-system coupling loss in actual operation of a motor, so that the operation point of the motor is obviously deviated from a comprehensive high-efficiency area, and the energy consumption advantage of a double-motor framework cannot be fully exerted. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides the intelligent torque distribution control method and the intelligent torque distribution control system for the pure electric four-wheel drive automobile, and the comprehensive energy efficiency optimization of the whole automobile driving system under various working conditions is realized by collecting the environmental parameters and the running states of the motor in real time and dynamically optimizing the torque distribution coefficients. To achieve the above object, one or more embodiments of the present invention provide the following technical solutions: The first aspect of the invention provides an intelligent torque distribution control method for a pure electric four-wheel drive automobile; An intelligent torque distribution control method for a pure electric four-wheel drive automobile comprises the following steps: collecting running state parameters, battery parameters and environmental parameters of an electric drive system of a vehicle in real time; Calculating the wheel end required torque under the current working condition based on the running state parameters, the battery parameters and the environmental parameters of the electric drive system; based on the current vehicle speed and the wheel end required torque, acquiring a plurality of candidate torque distribution coefficients; Calculating total power loss generated by the front and rear electric drive systems after distributing torque according to the coefficient aiming at each candidate torque distribution coefficient; And controlling the torque output of the front motor and the rear motor based on the optimal torque distribution coefficient. The running state parameters comprise ambient temperature, vehicle speed, accelerator and brake data, the battery parameters comprise battery SOC, battery voltage, battery current, maximum allowable charge and discharge power of the battery and battery temperature data, and the ambient parameters of the electric drive system comprise cooling water temperature, electric drive controller temperature, electric drive stator and rotor temperature, oil