Research On Drive Control Strategy Of Pure Electric Vehicle Based On Driver’s Style And Road Condition

Due to limited petroleum resources,rising prices and increasingly severe environmental pollution,pure electric vehicles have begun to enter the public’s field of vision due to their zero pollution,low emissions,and low noise.The vehicle controller is the brain of a pure electric vehicle,and it directs the execution of the lower-level controllers at all levels.Drive control strategy is one of the most core content of vehicle control strategy,which is closely related to the power and drivability of the vehicle.Therefore,in order to achieve better vehicle performance,it is particularly important to formulate a reasonable and feasible drive control strategy.In the complex closed-loop system composed of human-vehicle-environment,the impact of driver behavior on the entire vehicle cannot be ignored.At present,more drive control strategies mainly consider the aspect of driving intention,and there are few researches on driving style.Therefore,This paper proposes a drive control strategy that combines driver style,driver intention and road conditions to control the output drive torque,so that the vehicle can achieve the driver’s expectations to the greatest extent.The main research contents of this paper are as follows:(1)First,analyze the structure of the pure electric vehicle power transmission system in this paper.Based on the basic parameters of a target model,according to national standards and market research,design performance indicators,select the drive motor and power battery of the key components of the transmission system and design the parameters.(2)Through the research of the basic theory of drive control strategy,on the basis of traditional control strategy,according to the presence or absence of the accelerator pedal,the driving mode with the accelerator pedal participation is proposed.The driving mode is designed with the acceleration average value and the average value of the accelerator pedal change rate as input.The fuzzy controller for driver style recognition uses the torque load coefficient curve in the power mode and the torque load coefficient curve in the economic mode as the boundary,and uses the driver’s style recognition results to adaptively adjust the torque load coefficient curve to achieve The control of the reference torque;the electric climb mode without the accelerator pedal participation,this mode meets the requirements of not "rolling backward" when starting uphill,and not "carrying over" when starting downhill,which improves the stability and safety of starting.(3)A control strategy based on the driver’s intention and road conditions to dynamically correct the torque is formulated.According to the driver’s acceleration urgency,the driver’s acceleration intention is subdivided into slow acceleration,medium acceleration,and emergency acceleration.The road condition mainly considers the factor of slope,and the estimation of slope is completed according to the kinematic force analysis when the car stays on the road.Based on this,the driving intention recognition results and the slope are used to determine the compensation torque under flat road conditions and climbing conditions.Finally,the final motor demand torque is obtained on the basis of the reference torque.In order to prevent the occurrence of motor overheating and battery over-discharging,the motor overload management and battery power limiting strategy are proposed to further restrict the output torque,so as to improve the driving safety of the vehicle and the power adaptability to different working conditions.(4)Based on experimental data and theoretical research,the vehicle model and control strategy model are built in the Matlab/Simulink simulation platform,and the offline simulation analysis of the strategy is completed.The results show that the established drive control strategy has improved the vehicle dynamics and compared with the traditional control strategy,it has been optimized and has certain rationality and feasibility.