Development of one-DOF robot arm equipped with mechanical impedance adjuster

In order to realize constraint tasks by a manipulator, it is effective to adjust the joint impedance to the appropriate value. Most of the previous studies use the active force control method that uses information from force sensors. Using this method, the performances are limited by the responses of the servo systems, the non-linear characteristics of the force sensors and the dynamics of the manipulator. The object of this study is to adjust the joint impedance of the manipulator to an ideal degree by a mechanism which consists of a spring and a damper. In a previous study, the authors proposed a compliance adjustment method using the spring mechanism, the structure and control of the pseudo-damper system, and simple control algorithms for the coordinated system. In this paper, the authors discuss the evaluation of the effect of these mechanisms and the control method using the 1-DOF Arm Model which was newly developed as a base model to build a multiple degrees of freedom manipulator.