Optimal design for a self-adaptive mobile robot based on virtual center of motion

This paper presents an innovative locomotion concept with virtual center of motion (VCM) which can improve the performance of the mobile robot on rough terrain. The mechanism with the character of VCM is one of the limited degree of freedom (DOF) mechanisms in nature. This allows for simplifying the static model of the mobile robot. The VCM was applied to mobile robots to extend their climbing capabilities on terrain for its features. The front jockey mechanism of the robot was optimized through analyzing the relationship between the VCM and the level of the front wheel axis. In order to minimize the friction coefficient of the wheels, the parameters and the suspension position of the spring on the jockey were optimized through static analysis. An optimized prototype has been designed and developed. Experimental results show that the robot is able to passively overcome obstacles approximately up to 2.1 times its wheel diameter and climb up steps over 1.27 times its wheel diameter.