Design of force controller based on frequency characteristics

Abstract

This paper proposes a method to design a force controller based on frequency characteristics. Generally, force control algorithms are classified into two types, the explicit force control algorithms such as hybrid position/force control and the implicit force control algorithms such as impedance control. The explicit force control algorithms control the contact force directly, while the implicit force control algorithms control the manipulator motion-force relation. Recently, Goldenberg and others have shown the equivalence of these two types of algorithms. In this paper, we propose a method to design an explicit force controller based on its equivalence to the impedance controller, so that the resultant control system has desired frequency characteristics. The method is applied to a manipulator with one-degree-of-freedom and experimental results illustrate the effectiveness of the proposed method.