Integrated driving torque control system for automotive vehicles with continuously variable automatic transmission

Abstract

An integrated driving-torque control system for an automotive vehicle with a continuously variable automatic transmission (CVT) and an electronically-controlled engine, comprises a desired transmission ratio arithmetic-calculation circuitry calculating a required axle-driveshaft driving torque from an accelerator depression amount and a vehicle speed, and retrieving a desired transmission ratio on the basis of the required axle-driveshaft driving torque and the vehicle speed VSP. An electronic control unit (ECU) executes automatic shifting control for the CVT so that an actual transmission ratio is adjusted to the desired transmission ratio. A first arithmetic-calculation circuitry calculates a first desired engine output torque corresponding to the required axle-driveshaft driving torque, whereas a second arithmetic-calculation circuitry calculates a second desired engine output torque corresponding to the accelerator depression amount. A selector selects the first desired engine output torque as a desired engine output torque under a condition of VSP&gE;VSP,(a predetermined vehicle speed threshold), and selects the second desired engine output torque as the desired engine output torque under a condition of VSP<VSP,. The ECU executes engine power output control for the engine in response to the desired engine output torque selected by the selector.