Cooperative control of two mobile manipulators transporting objects on the slope

This paper reports our recent results on the motion control of cooperative transportation by two mobile manipulators following a reference trajectory on the slope. We propose a cooperative control algorithm which is divided into two steps. In the first step, the mobile manipulators regulate their postures to keep themselves away from falling using their redundant Degree-Of-Freedom. If the robots still cannot keep stable, then in the second step, both robots adjust their forces acting on the transported object to avoid falling. Simulation results are given to validate the proposed method.