Consensus control of flexible joint robots

Synchronization of networks composed by fully-actuated robot manipulators has received a lot of attention from the control theory community. Unfortunately, the case of under-actuated robots has not been deeply studied. The aim of this paper is to extend previous results reported by the authors [2] addressing the particular (but of practical interest) case of networks composed by flexible-joint robots. The main feature of the contribution is to consider a change of coordinates, first introduced in [1], to solve the consensus problem assuming the existence of unknown delays in the communication channels. The extensions consist in: the presentation of a control scheme that, in contrast to the one considered in [2], does not require knowledge of the initial conditions; the proof that the controller can also be implemented in Cartesian coordinates; and the statement of the stability properties adopting a Cascaded systems perspective. The usefulness of the contribution is illustrated through numerical simulations.