Research On Control Strategy Of Pure Electric Vehicle Brake Energy Recovery System Based On Fuzzy Control

In response to the current global energy crisis and environmental problems,new energy vehicles,as new technology vehicles that use unconventional vehicle fuel as a source of power or new power devices,have been the only alternative to traditional fuel vehicles.Among them,pure electric vehicles have many advantages and are deemed to be the most promising new energy vehicles.However,due to the short range and long charging time,pure electric vehicles limit their popularity.The braking energy recovery system can reduce the energy dissipation to a certain extent and improve the cruising range.This paper analyzes the influencing factors of braking energy recovery,starting from the braking energy recovery control strategy,the main research contents are as follows:(1)The selection and parameter matching of the driving motors and power batteries of the core components of pure electric vehicles,building the vehicle model in CRUISE software and carrying out simulation verification of power and economy,and formulating braking energy recovery control strategies and follow-up Co-simulation provides the basis for the complete vehicle model.(2)Establish a dual fuzzy control strategy model based on the driver’s braking intention,and formulate the braking intention recognition fuzzy controller and the braking energy recovery proportional fuzzy controller from three aspects: input and output parameter selection,membership function construction and fuzzy rules.According to the types of membership functions of front and rear fuzzy controllers,four dual fuzzy controller structures are compared to determine the braking energy recovery ratio on the premise of identifying the driver’s braking demand intensity.(3)Based on the ideal I curve,ECE regulations and road conditions,put forward segmented curves of front and rear wheel braking force distribution for good road surface and extreme road weather,and build front and rear wheel braking force distribution under good road surface in Simulink model.(4)Build a collaborative simulation platform based on MATLAB / Simulink and CRUISE software,and select NEDC,WLTC and CLTC-P three cycle conditions for simulation test analysis according to the urban traffic situation in China.Taking thechange of battery SOC value and cruising range as the evaluation criteria under different working conditions,the validity and effectiveness of the braking energy recovery strategy set out in the present paper are verified.This paper proposes a double fuzzy control strategy to provide a new control strategy for the development and design of the vehicle controller in the electronic control unit of a pure electric vehicle,which has important practical engineering significance and predictability.