A system has an acceleration region SU and a deceleration region SD between operation start and end positions of a wiper arm. In the acceleration region and the deceleration region, an addition amount and a subtraction amount are calculated, respectively, based on a difference between a maximum rotation speed and a current rotation speed to update a target rotation speed. The addition amount is larger than the subtraction amount, and a constant speed region CV is between the acceleration region SU and the deceleration region SD. When a change amount of an operation angle of the wiper arm does not exceed the constant speed region CV, the operation angle change amount is subtracted from the constant speed region. Further, when the operation angle change amount exceeds the constant speed region CV, the target rotation speed is updated by the same change amount.