Virtual Target Strategy in Fuzzy Navigation of Reactive Mobile Robots

Abstract

Abstract Reactive mobile robot often suffers from a so-called limit cycle problem – the robot wanders indefinitely in a loop in the course of navigation in unknown environment. In this study the cause of the limit cycle is analysed intuitively and then proved mathematically, leading to a necessary condition for identifying the critical points from which the robot likely starts a limit cycle path. By taking into account the abrupt change of the target orientation at the critical points, a virtual target strategy is proposed for resolving the limit cycle problem, in which the real target is switched to a virtual location following the critical point and the robot is navigated according to the virtual target set up temporarily and the real environment information sensed, until aswitching-back condition is reached. The condition for switching back to the real target is established using a specific change in the obstacle information sensed. Main features of the proposed strategy are highlighted by comparing wi...