A Novel Approach to Master and Slave Control by Force Feedback Based Virtual Impedance Controller

Abstract

A field of research which deals with tactile sensation is called haptics. Many researchers have been investigated haptics in recent years. In the past research, 4ch bilateral controller based on torque/force sensorless approach is developed so as to achieve high transparency as teleoperation systems. In actual system with geared motor, however, the high transparency leads to instability because of disturbances. In particular, the geared motor has a large joint friction which affects the torque/force sensorless control, though its cost is low. This means that the high quality of tactile sensation is not expected in case the geared motor is used in experimental system. To improve the effect of friction, linear motor is often utilized in the past research, though its cost is high. To address this issue, his paper focuses on a novel control strategy to realize low cost teleoperation systems based on the geared motor, that is, master and slave systems. To reduce the effect of joint friction, a novel approach to master and slave control by force feedback based virtual impedance controller is proposed. By using the proposed method, position and force controllers can be designed independently and it is one of remarkable features. To verify the validity of proposed method, the performance of the controller is analyzed and evaluated by using "Reproducibility" and "Operationality". Furthermore experimental validation is conducted with 1-DOF manipulator.