Collaborative transportation with 3 mobile manipulators and human interaction

Nowadays multi-robot system (MRS) is becoming more and more popular in the industrial field taking advantage of its improved robustness and efficiency compared to single-robot system. In fact, many tasks, such as object transportation, can benefit from MRS's flexibility and reliability to extend the load-carrying capacity. In this work, a centralized controller is proposed to provide the reference velocities for each arm grasping the object and a fixed formation of 3 robots is used to carry and keep it in the center. The object position displacement w.r.t. the initial position is used to move the bases of the manipulators in the direction of the displacement. In this way, the higher controller moves the object within the bases to control the velocity of the entire formation. Furthermore, this approach allows the human to directly command the formation, by acting as the higher controller, pushing or pulling the object. Experiments using Hebi Rosies mobile manipulators are demonstrated in order to validate the theory.