Design and performance analysis of retractable-clawwheels for field robots

This paper presents a new retractable-claw wheel with six sets of claw mechanism to improve the capability of climbing obstacles. The structure and performance of the retractable-claw wheel is analysed. A robot prototype named as Rabbit is developed with retractable-claw wheels. The experimental results show that the Rabbit robot can move smoothly in various terrain conditions (e.g., flat, step, slope, and multiple-obstacle). Experiments demonstrate that the retractable-claw wheels enable the robot to traverse over steps whose height is 1.4 times of the wheel radius; over sloped terrains up to 40? tilt angle, which is much larger than conventional robots can do. The retractable-claw wheels are proved to be suitable for planetary rovers or field robots.