A motor drives a window glass of a door of a vehicle in an opening
direction and a closing direction. A rotation sensing device outputs a
pulse signal in response to rotation of the motor. A controller senses
pinching of an object by the window glass based on the rotational speed
signal. Specifically, the controller computes a rate of change in the
rotational speed, i.e., a rotational speed difference based on the
rotational speed signal. The controller senses start of the pinching
based on the rotational speed difference. When an amount of change in the
rotational speed since the time of sensing the start of the pinching
exceeds a pinching determining threshold value, the controller confirm
the pinching of the object.