Abstract: A basic requirement for autonomous guided vehicles or indoor autonomous mobile robots is that they should be able to avoid obstacles in unknown environment and successfully arrive at the predetermined destination. Bug and its derivative algorithms are famous sensor-based navigation algorithms which can meet the above-mentioned requirement. They hold that a robot is a point on a plane, having a 360° sensing range, capable of skirting any obstacle. However, Bug algorithms cannot be directly applied to the ordinary robot with physical dimensions and a non-360° sensing range. A novel and practical method to accomplish inherently collision-free boundary following is presented so that DistBug algorithms, a derivative from Bug algorithms, can be implemented on these mobile robots, which features the following: A straight path technique reducing robot’s motion to pure turning and pure translation; Pure turning is further divided into three classes to serve different purposes; virtual antennae are used to utilize sensory data to provide inputs to the whole algorithm for decision making. Based on this boundary following method a practical goal directed navigation approach for robots equipped with non-360° sensing system is implemented, which is tested with a Pioneer 3-AT mobile robot where a 180° laser range finder fits.

Key words: Autonomous navigation, Mobile robots, Non-360° sensor, Obstacle avoidance, Virtual antenna