Sensorless Positioning Control of Single-Link Robot Arm by Means of Sliding Mode Observer-Controller.

摘要

The advantages of applying sensorless control to mechanical systems are cost reduction, prevention of instability of the control system by collocation, noise reduction, decrease of breakdown frequency, increase of reliability and space saving. In this study, we deal with a sensorless positioning control problem of a single-link robot arm with nonlinear friction torque at the drive system. The state of the system is estimated by means of an observer from the angular velocity obtained indirectly from the coil current of the motor to drive the arm, and controlled by a controller. In order to realize such a control system, robust performances are required in the state estimation in addition to the control law. We combined a sliding mode observer and a sliding mode controller to construct a nonlinear robust control system. Then, we applied it to the motion control system of the robot arm. Finally, we investigated the performance with regard to positioning control of the arm.