Precision turning of non-symmetric micro-structured surfaces based on FTS

A precision diamond turning system for fabrication of non-symmetric micro-structured surfaces based on fast tool servo(FTS) system is proposed.The fast tool servo is driven by a piezoelectric actuator along with a capacitive displacement sensor.To overcome the inherent non-linearity of the piezoelectric actuator,an inverse model of FTS is constructed using neural network and expended input space.Besides,PID feedback control is also implemented to achieve better tracking performance.Actual testing data show that the following error is less than 150 nm.The fabrication of a sinusoidal grid surface has indicated the effectiveness of the fabrication system.