Design of a Force Controller Based on Frequency Characteristics

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, implicit force control algorithms control the manipulator motion-force relation. Recently, the equivalence of these two types of algorithms has been shown by A. A. Goldenberg (1992), and R. Volpe and P. Khosla (1993). In this paper, we propose a method to design an explicit force controller based on the equivalence to the impedance controller, so that the resultant control system has the 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.