To provide a device to control a torque transmission system, such as a clutch in the drive system of an automobile, and a transmission and provided with a control unit and at least one actuator, the control unit controlling at least one actuator to operate a torque transmission system and switch the transmission ratio of the transmission, and the control unit to provide comfortable operation characteristics during a controlled gear switching process by improving at least one sensor and an apparatus connected to an engine electronics by a signal.

During an automatic controlled switch process of the transmission ratio of a transmission executed by an actuator, the number of revolutions of a drive unit 1 is intentionally reduced at least at a first stage by controlling an engine electronics 20 through the working of a control unit 7. The number of revolutions of the drive unit 1 is intentionally increased at a second stage through control by the control unit 7.