A Fast Response Piezoelectric Actuator for Servo Correction of Systematic Errors in Precision Machining

Summary A piezoelectric actuator has been developed for use in the on-line correction of systematic machine errors, which would otherwise cause errors in workpieces on metal cutting machines. The actuator consists of piezoelectric elements for producing small displacements, parallel diaphragms constraining movement to one linear direction, a Linear Variable Differential Transformer (LVDT) for sensing position, and a microprocessor system for closed-loop positioning control. The actuator has 10 nm positioning accuracy over the total range of 6 μm, positioning bandwidth is 50 Hz, and axial stiffness is 300 N/μm.