Coordinated motion control of multiple mobile manipulators based on virtual 3-D caster

In this paper, we propose two types of cooperation system, of multiple mobile manipulators based on the caster-like dynamics referred to as virtual 3-D caster for handling a single object in 3-D space. One is the human-robots cooperation system, in which a human handle a single object in cooperation with multiple mobile manipulators. The other is the leader-follower type cooperation system, in which a mobile manipulator referred to as leader handle a single object together with other mobile manipulators referred to as follower. In both control algorithms, the grasping point of each mobile manipulator is controlled as if it has a caster-like dynamics in 3-D space, so that the multiple mobile manipulators could realize the cooperation for handling a single object without using the geometric relations among the robots. The proposed control algorithms are experimentally applied to multiple mobile manipulators, and the validities of the proposed control algorithms are illustrated by the experimental results.