Cooperative Control Based on Absolute Positional Information of Grasped Object in Multiple Mobile Manipulators

Abstract

This paper describes a control strategy to realize grasping and cooperative motion in multiple mobile manipulators. In the general approach, the stable grasping motion is well realized, but the emergent motion such as the obstacle avoidance motion and the collision avoidance motion among the robots are not taken into account in the cooperative motion of multiple mobile manipulators. In the practical application, however, the above issue is important to realize an adaptive and sophisticated motion. The proposed approach introduces the null space motion based on the grasping matrix and the absolute position of target object in the grasping motion of the manipulator. In this case, each motion of mobile manipulator is given independently of the grasping and the cooperative motion, and the emergent motion is determined arbitrary. This is one of the remarkable features of the proposed strategy. Several numerical and experimental results show the validity of the proposed approach.