Increasing friction braking in an electric vehicle when regenerative braking torque is limited

摘要

A method and system for the management of regenerative and friction braking in a motor vehicle having two processors 12,14 which process vehicle data. The two processors 12,14 are interconnected and interact such that when the operating data from one operating data source indicates that regenerative braking torque does not require to be limited, the torque modification data supplied to the first processor from the second processor equates to the brake torque request data, and the friction brake torque data does not cause the friction brakes to be applied but when the operating data operating data source indicates that the regenerative braking torque needs to be limited (eg. high battery charge) then the amount of limiting is subtracted from the torque modification data and is used as the amount of friction brake torque required to be supplied by application of friction brake means.