Disturbance observers have been used extensively for decouplingcontrol of robot manipulators. But the conventional disturbanceobservers are sometimes useless for decoupling control because they areusually constructed under the assumption that the disturbance isconstant during the sampling period and the trade-off between decay rateof the estimation error and the sensitivity to sensor noise is aninevitable problem. This paper proposes a variable-structure disturbanceobserver and a method for decoupling control of robot manipulators byapplying the proposed observer. The proposed observer can treat ageneral class of disturbances and overcome the problems of theconventional disturbance observers, that is, sensitiveness to sensornoise and delay of convergence. The proposed control method isimplemented into an experimental 3-degree-of-freedom DD robot. It isshown through experimental results that the proposed method can realizedecoupling control for robot manipulators more precisely and robustly
展开▼
