Cooperative regenerative braking control strategy considering nonlinear tire characteristic in front-wheel-drive hybrid electric vehicle

An electric motor for regenerative braking in front-wheel-drive hybrid electric vehicle is only connected to the front axle, and mechanical friction braking can be independently applied on each of the 4 wheels. Excessive regenerative braking only at front wheels to improve fuel economy can cause under-steer and eventually vehicle instability. Nonlinear tire characteristic may cause this vehicle instability in severe cornering with hard braking. Therefore, cooperative braking control strategy has to be considered nonlinear tire characteristic for guaranteeing the vehicle stability while enhancing the braking energy recovery. This paper is to compare the performance of cooperative braking control strategy according to consider the influence of braking force on the lateral force. Carsim™ software is used to evaluate the performance of cooperative regenerative braking control regarding to the vehicle stability and regenerative braking efficiency.