Proper selection of sonar and visual sensors for vehicle detection and avoidance

The general paradigm for vehicle detection and avoidance by proper selection of visual and sonar sensors are proposed. The most appropriate sensor for robot detection and navigation is properly selected depending on its functions. Four types of actions based on stereo-typed motion are used for the navigation of the robot: moving along wall, moving alone;, moving forward and tracking motion. The first approach is based on sonar, and the remaining are vision based actions. The visual detection of vehicle is based on the locomotion strategy: the sign pattern based stereo-typed motion. The sign pattern of vehicle is the shadow underneath the vehicle which is darker than any other parts of the asphalt paved road. The robot detects the sign pattern of vehicle from the distance of 30m and extracts its front shape in real time processing