Research On The Integrated Control Of Regenerative Braking And Anti-lock Braking For An Electric Vehicle

As energy shortage and environmental pollution problem being more and more serious,electric vehicle has become the focus of attention in the automotive industry.The main factor hindering the marketization of electric vehicle nowadays is its short driving mileage.The electric vehicle regenerative braking can recover some braking energy and prolong the mileage of electric vehicle,but it also increases the complexity of electric vehicle braking system,so it's necessary to develop regenerative braking control strategy to allocate braking force reasonably.As modern car must be equipped with anti-lock braking function,how to coordinate regenerative braking and anti-lock braking is also an important research topic in the field of electric vehicle.Based on a national science and technology supporting electric vehicle project,research on the integrated control of regenerative braking and anti-lock braking for electric vehicle is done in this dissertation and the research works mainly include the following aspects:Firstly,the layout of the electric vehicle,the braking system,the motor,the battery and the transmission devices are selected and matched firstly on the basis of the main parameters and design performance indexes of the vehicle.Then the vehicle performance is simulated based on the ADVISOR software and the simulation results verify the rationality of the parameter matching.After that,the regenerative braking control strategy for electric vehicle is designed and its model is built based on the Simulink.Then the model is embedded in the EV model in the ADVISOR and the effect of braking energy recovery under typical conditions is simulated.Simulation results show that the regenerative braking control strategy is better than the default one in the ADVISOR.Then,a method of identifying the optimal slip rate of pavement based on fuzzy reasoning is put forward.A sliding mode control law for the optimal slip rate control is designed based on the mixed approach law and the sign function in the approach law is replaced by the hyperbolic tangent function in order to weaken the buffeting.Lastly,the integrated control strategy of regenerative braking and anti-lock braking based on optimal slip rate sliding mode control for electric vehicle is formulated.Based on the CarSim and Simulink co-simulation platform,the braking simulation model of electric vehicle is built.The optimizing method based on genetic algorithm and off-line simulation to look for the optimal values for the parameters of the approach law of the sliding mode control is proposed.Simulation results show that the fuzzy identifier can identify the optimal slip rate of the pavement,and the anti-lock braking strategy is effective,and the wheels are control at the optimal slip rate,and some braking energy is recycled.Sliding mode controller with the optimal parameter values can get better control effect and improve the braking performance of vehicle.