Torque control strategy for management of creep and grade hold torque in a wheeled vehicle whose powertrain includes a rotary electric machine

摘要

A torque control strategy control for management of regenerative braking in a motor vehicle. A first processor (12) processes throttle request data (20) and torque modification data (40) from a second processor (14) to develop motor torque request data (28) for controlling rotary electric machine torque. The second processor processes brake request data (26), the throttle request data, and operating data from the at least one operating data source to develop friction brake torque data (30) for controlling friction brake torque applied to the vehicle and the torque modification data for the first processor. The two processors interact such that as long as the operating data from the at least one operating data source does not require that regenerative braking torque 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, and when the operating data from the at least one operating data source calls for some limiting of the regenerative braking torque, the amount of limiting is subtracted from the torque modification data and the friction brake torque data equates to that amount of limiting for causing the friction brakes to be applied in that amount. At zero and near-zero speeds grade hold torque is calculated according to a formula and added to the friction torque.