Force Controlled Assembly of a Ring-shaped Elastic Part Based on Dynamic Characteristics of Skilled Workers

Abstract

This paper proposes a novel method for assembling a ring-shaped elastic part to a cylinders’ outer groove by using an industrial robot. To assemble a ring-shaped elastic part, forces acting on an elastic part should be made as small as possible. In our proposed method, while the force control strategy itself is determined based on the human characteristics, the parameters of the controller is determined by using a numerical optimization. First, the position data and the force data while a human demonstrates the assembly are measured. Then they are qualitatively analyzed and two control methods are derived. However, we do not obtain the parameters of the force control from the human data. This is because the performance, for example the response characteristics, of robots is different from that of human and the parameters obtained from human data are not necessarily suitable for robots. Thus we obtain the parameters by an optimization with the downhill simplex method which is feasible for an optimization based on actual machine. To confirm that the applied force is significantly reduced, we conduct experiment and compare two force control methods.