Patent ID: 6278916
Filing Date: 2001-08-21
Classification: B60L,Y02T

Abstract:
A motor vehicle comprising:road-engaging wheels;a powerplant comprising a rotary electric machine that is operatively coupled through a drivetrain to the road-engaging wheels and that is capable both of delivering traction torque to the wheels and of imposing regenerative braking torque on the wheels;friction brakes for applying friction brake torque to the wheels;a throttle request source;a brake request source; aat least one operating data source furnishing operating data that, at certain times, calls for limitation of regenerative braking torque;at least one processor for processing throttle request data from the throttle request source and torque modification data to develop motor torque request data for controlling rotary electric machine torque and for processing brake request data from the brake request source, the throttle request data, and operating data from the at least one operating data source to develop friction brake torque data for controlling friction brake torque applied to the wheels and the torque modification data;wherein 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 equates to the brake torque request data from the brake request source, 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; andwherein for vehicle speeds greater than zero speed, but less than or equal to a threshold, a grade hold friction brake torque that is a function of vehicle speed is added to the friction brake torque data.