The purpose of this study is to combine ultrasonic and CMOS image sensors In this study, CMOS image sensor was used to deal with small obstacles and to retrieve image information in front of the robot. In this work, ultrasonic sensors are adopted to implement a real-time obstacle avoidance system for wheeled robots, so that the robot can continually detect surroundings, avoid obstacles, and move toward the target area. Secondly, six ultrasound sensors installed on the wheeled robot were utilized to detect large obstacles and to obtain distance information between the robot and the obstacle. The PD controller was used in the wall-following method to achieve the optimized path design. Experimental results verified that ultrasonic sensors of the obstacle avoidance system on the wheeled robot, with ATMega162 embedded microcontroller as the core of the system, can indeed help avoid obstacles and reach the established target area.