The coordinated control of motor regenerative braking torques defined by accelerator pedal and brake pedal of electric vehicle

Driver can operate accelerator pedal and brake pedal to control the driving force and the braking force exerted on vehicle. For electric vehicles, it is possible that the braking force can be controlled by manipulating the accelerator pedal because of the regenerative braking function. In this paper, fuzzy control theory is employed to calculate regenerative braking force during releasing accelerator pedal based on the accelerator pedal opening and its change rate. Two modes are designed to coordinate the braking forces defined by accelerator pedal and brake pedal. One mode is engine braking imitation mode, and the other is auxiliary braking mode. The simulation results show that engine braking imitation mode can provide the similar driving feel to internal combustion engine vehicle. Auxiliary braking mode changes the traditional driving habit, but it has much higher regenerative efficiency. Auxiliary braking mode is suitable for the city driving condition which has frequent braking requirement.