RoMop: A New Type of Wheeled Mobile Platform Based on Rotating Locomotion

To address the problems of conventional mobile platforms for mobile manipulators, this article proposes the design and control of a new type of mobile platform, whose locomotion method is based on constant rotation. The proposed mobile platform is actuated by three conventional wheels, each of which is connected to the main body by a single-DOF passive planar motion mechanism. By rotating the platform during locomotion, multidirectional translation can be realized by avoiding singular configurations. The proposed mobile platform offers benefits in terms of high maneuverability, high precision, and low vibration. In this article, the mechanism and kinematics of the proposed mobile platform are first presented. Based on the singularity analysis, applicable locomotion methods and the design conditions of the planar motion mechanism are discussed. An example of the proposed mobile platform is introduced, and its kinematic characteristics and approximate model are then presented. To achieve obstacle and tip-over avoidance, a trajectory tracking control system based on model predictive control and a path planner was also developed. Finally, experiments using the prototype are presented. The results verify the effectiveness of the developed mobile platform and its control strategies.