Steuervorrichtung und Steuerverfahren für ein Kraftfahrzeug

摘要

The device has a turbine wheel revs. rate detector (14), an engine revs. rate detector (10), a memory unit (6) and a controller (6,20). The memory unit stores a characteristic relating the capacity of the torque converter (2a) to its revs. rate and a characteristic relating the engine (1) torque to its speed.The controller derives the converter speed from the detected engine speed and turbine wheel speed to obtain the actual engine torque ratio and stored capacity characteristic. A magnitude ratio between the actual torque and the estimated torque is derived and used to determine whether the vehicle is operating at high or low road altitudes, i.e. in relatively low or high air density. An engine parameter and/or the transmission is or are controlled accordingly to achieve a desired ratio between the actual and estimated torques.