Research On Distribution Strategy For Pure Electric Vehicle Braking Force Based On Fuzzy Control

Electric vehicles as an effective means to improve the situation of energy shortage and environmental pollution, its limited driving distance and short battery lifespan have become the key factors that obstruct its industrialization. When the electric vehicle is decelerating or braking, with the function of regenerative braking system it will convert braking kinetic energy into electric power, thus to achieve the purpose of recycling braking energy. This thesis uses front-wheel-drive of EVs as research objectives by navigating the contents of regenerative braking control strategy which in other words is using braking force distribution to serve the purpose of improving the braking energy recovery efficiency. The main works are as follows:Firstly, in the light of the inadequate of the traditional power distribution control system, by taking advantage of the analysis of dynamic vehicle braking processing, this paper introduces an improved braking force distribution control strategy which to put another way, is to let the front wheel bare more braking force under the base of ensuring the safety and stability of vehicles braking by taking different power distribution of the front and rear wheel according to the braking strength.Secondly, in contrary to the influential factors of recycling braking energy and the difficulties of establishing a precise mathematical model, this article brings up the fuzzy controller based on the fuzzy control theory, in which the input is braking strength, vehicle speed and battery state of charge based and the proportion of regenerative braking force and front wheel braking force are three times input and single time output. At the mean time, this thesis achieves the purpose of building simulation control strategy model by designing fuzzy controlling regenerative braking control strategy combined with the proposal of improved braking force distribution strategy.Thirdly, to test the simulated software of regenerative braking control strategy model that built in with fuzzy control, this paper chooses three typical road cycling condition which are UDDS, ECE, NYCC to conduct comparison of simulation with the analysis of the built-in front and rear braking force distribution strategy of ADVISOR software. The simulation result shows that braking control strategy designed in this paper performs much better than the braking control strategy built-in ADVISOR software in terms of braking energy recycling efficiency, thus to verify the effectiveness of the strategy established in this thesis.