A fast tool feeding mechanism using piezoelectric actuators in noncircular turning

Piezoelectric actuators have wide applications because of their indefinite resolution and high stiffness, for use in optical devices, measurement systems and ultra-precision machine tools. In noncircular turning, the tools feeding servo should be long-travel, high-frequency and high-precision. In order to meet these requirements, a new flexure-hinge structure is used to amplify the output displacement of piezoelectric actuators. A hybrid of feed-forward control in the disturbance channel, repetitive control and Proportion and Integration control (PI) are also employed to better the tracking precision and robustness of the system.