Transmission system for vehicle

A transmission system for a vehicle comprising:

• a clutch disposed in a power transmission path between an engine and a vehicle wheel;
• a transmission disposed in the power transmission path, a clutch actuator that switches the clutch between an engaged state and a disengaged state;
• a shift actuator that switches a shift stage of the transmission;
• a vehicle wheel speed sensor that detects a rotational speed of the vehicle wheel as a detected rotational speed;
• a sudden deceleration detecting unit that detects whether a predetermined sudden deceleration of the vehicle wheel occurs based on the detected rotational speed;
• and
• a shift control unit that executes an ordinary shift control in response to the sudden deceleration detecting unit detecting no predetermined sudden deceleration is occurring, and executes a sudden deceleration adaptive shift control in response to the sudden deceleration detecting unit detecting the predetermined sudden deceleration of the vehicle wheel,
• in the ordinary shift control, the shift control unit controlling the clutch actuator, and further controlling the shift actuator to shift to a current speed adaptive shift stage selected from a plurality of speed adaptive shift stages based upon a value of the detected rotational speed, and
• in the sudden deceleration adaptive shift control, the shift control unit controlling the clutch actuator, and further controlling the shift actuator to shift to a current sudden deceleration shift stage selected from a plurality of sudden deceleration shift stages based upon the value of the detected rotational speed or a predicted speed, the current sudden deceleration shift stage being
• lower than an actual shift stage at the time of detection of the predetermined sudden deceleration, and
• higher than the current speed adaptive shift stage executed in the ordinary shift control with the detected rotational speed.