Fuzzy Behaviour Based Navigation of a Mobile Robot for Tracking Multiple Targets in an Unstructured Environment

This paper presents fuzzy behaviour based control for a differential drive mobile robot in an unstructured environment capable of tracking priority based multiple targets. Behaviours implementation is done by incorporating the obstacle range data from each ultrasonic range finder, current location of mobile robot and selected target location based on its priority. This behaviour based control architecture is composed of two layers; the first layer selects a group of behaviours and second implements controller actions for the selected group. The layered architecture reduces the rule base as well as allows further decomposition of behaviours. The behaviour conflict management is done by using inhibition at first layer and suppression at second layer. The selection of the next target to be tracked is done on the basis of predefined priorities and conflict among equal priority targets is resolved by minimum Euclidean distance measure. Simulation results verify the effectiveness of proposed method by implementing Obstacle Avoidance, Wall Following, Corridor Following, Target Steering and Emergency behaviours successfully in a single, and multiple target environments. Moreover the conflict management scheme for tracking multiple targets with equally priority is also validated. Key-Words: Fuzzy Behaviour Controls, Multiple Target Tracking, Obstacle Avoidance, Ultrasonic Range Finders