Simplification of motion generation in the singular configuration of a wheel-legged mobile robot

Abstract

Wheel-legged mobile robots (i.e., robots that use leg and wheel mechanisms) have the potential for efficient movement in response to the environment. Singular configuration is an inevitable problem in wheel-legged mobile robots and must be solved to realize motion. This paper proposes a simplification of the motion generation method in the singular configuration of a wheel-legged mobile robot. The problem of inverse kinematic calculations in a wheel-legged mobile robot is first modeled, and a solution method is proposed using an extension of the constraints to the acceleration level and the redundancy of the robot. The singular configuration problem in the low-speed region is then solved using the Levenberg–Marquardt method. A simple decision method using a weighted matrix for the damping factor is also proposed. The method is then verified using a three-dimensional simulation and an experiment.