Fuzzy Control of a Log Carrying Robot on Tree-Filled Steep-Sloping Terrains

A modular robotic system and its fuzzy logic based controller are proposed for use in logging operations in forest environments with steep slopes. The Log-Carrying Robot (LCR) concept is composed of two modular wheeled robotic agents with individual wheel steering that connect to the ends of a log to a form a centrally controlled robot. A fuzzy controller specifies the desired direction of travel using four factors: the presence of obstacles, boundaries limiting the robot’s travel space, the heading of the goal position relative to the robot, and the slope of the terrain. The capabilities of the proposed controller are demonstrated in simulation using a rectangular robot with four individually actuated and steered wheels. Results indicate that the controller successfully steers the robot towards the goal position while avoiding obstacles using only eleven fuzzy rules. Additionally, the simple rules are shown to be effective at automatically compensating for sloped terrain by avoiding direct travel down hills, as well as adapting for various robot lengths