In this study, the trajectory of a mobile robot is controlled by using a method based on the time state control form. It is possible to adjust the control parameters of this robot based on linear control theory. The distance to obstacles is measured by using a laser range finder. When the robot approaches to obstacles, the proposed controller switches the traveling direction and the control gain of the rotating motion. In the experiments, the robot avoided the obstacles and reached the target position, traveling back and forth automatically. Futhermore, the switching position and control parameters were searched by using a genetic algorithm. The parameters found by genetic algorithm made it possible for the robot to reach the target position in a short time.