Position/force decoupling for micro-macro bilateral control based on modal space disturbance observer

A four channel bilateral control is one of the teleoperation techniques. In this control, position control system and force control system should be decoupled precisely. However, there is some interference between position control and force control, if the inertia of the master robot is different from slave side. In this paper, a diagonalization method using modal space observer is proposed for the sake of decoupling position control from force control. This method diagonalizes an equivalent mass matrix in a modal space, which is called task mass matrix. Operationality and reproducibility, which are performance indices, are indicated. Furthermore, root locus plots are shown to analyze the stability. The validity of the proposed method is verified by experiments. In other words, the decoupling effect of the diagonalization method is higher than conventional method, and more stable.