Nonlinear compensation method with bang-bang compensator for a high precision stage using synchronous piezoelectric device driver

The need for high precision and a fast response time in positioning tables in the machine tool and semiconductor fields has grown. To achieve such requirements, a synchronous piezoelectric device driver to control the stage has been proposed. The stage is driven by the scratching force of this device, but the control performance was shown to be affected by the nonlinear friction force. Thus, a friction compensation method which was based on PID+FF control with sliding mode compensator was proposed for a high precision stage control [1]. In this paper, we propose an alternative compensation method, consisting of the conventional method with a bang-bang friction compensator. Experimental results are given to show the effectiveness of our proposed method. Using our new method, the high frequency fluctuation phenomena in the control input becomes smaller than in the conventional method.