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In this study, a co-operative regenerative braking control algorithm was developed for an electric vehicle (EV) equipped with an electronic wedge brake (EWB) for its front wheels and an electronic mechanical brake (EMB) for its rear wheels. The co-operative regenerative braking control algorithm was designed considering the road friction characteristic to increase the recuperation energy while avoiding wheel lock. A powertrain model of an EV composed of a motor, and batteries and a MATLAB model of the control algorithm were also developed. They were linked to the CarSim model of the vehicle under study to develop an EV simulator. The EMB and EWB were modeled with an actuator, screw, and wedge to develop an EMB and EWB simulator. A co-simulator for an EV equipped with an EWB for the front wheels and an EMB for the rear wheels was fabricated, composed of the EV and the EMB and EWB simulator.

A regenerative braking algorithm is proposed to make maximum use of regenerative brake for improvement of fuel consumption. In the regenerative braking algorithm, the regenerative torque is determined by considering the motor capacity, battery SOC and vehicle velocity. The regenerative braking force is calculated from the brake control unit by comparing the demanded brake force(torque) and the motor torque available. The wheel pressure that is reduced by the amount of the regenerative braking force is supplied form the hydraulic brake module. In addition, CVT speed ratio control algorithm is suggested during the braking. The optimal operation line is obtained to operate the motor in the most efficient region. It is found from the simulation that the regenerative braking algorithm including the CVT ratio control provides improved fuel economy as much as 4 percent for federal urban driving schedule.