An analysis and design of bilateral control based on disturbance observer

In this paper, an analysis and design of bilateral control based on disturbance observer are discussed. Poles of bilateral control go to the poles of position control and poles of force control respectively when disturbance observer gain is infinite. Four-channel controller which is hybrid of position and force in the acceleration dimension based on disturbance observer can be divided into two modes: common and differential modes. Position is controlled in differential mode space, force is controlled in common mode space. Relationship between these spaces is revealed, design of bilateral control in the virtual space is proposed. According to this method, design of bilateral control can be treated as position control and force control about one robot separately. These theories are applied to the 6-degree-of-freedom industrial manipulator. The numerical and experimental results show viability of the proposed method.