Nano Positioning Control for Ultra-precision Machining using Inverse Hysteresis Model

In this study, inverse-hysteresis model, which can inversely calculate input voltage for desired displacement, is suggested for tracking performance. In this paper, tracking performance and movement precision of piezoelectric actuator as operating parts of ultra-precision cutting unit is improved using feedback control of inverse-hysteresis model to remove hysteresis property. PID feedback control is studied as controller to compensate the error in inverse-hysteresis model. In addition, straightness error of spindle, thermal expansion error of mechanical structure is analyzed to detect movement error property in ultra-precision machining. Via machining performance evaluation using ultra-precision machining experiments, the machining precision of ultra-precision CNC lathe can be improved.