Modelling of piezoelectric micropositioning system using direct mapping and numerical analysis for precision grinding process control

摘要

For microano positioning systems using piezoelectric actuators for precision grinding process control, sinusoidal command signals will be used and will give additional problems in comparison with the commonly used step signals due to the hysteresis effect, which require good modelling of the effect. To avoid discontinuity in obtaining the values of the piezoelectric constant, a method of direct mapping with polynomial fit has been proposed. Compared with the single polynomial approach, the model obtained was able to reduce the modelling error by 6.5%. To further reduce the modelling error, a new method using direct mapping and numerical analysis is proposed while discontinuity is avoided. Theoretical and experimental studies are conducted and comparative studies are made. Compared with the single polynomial approach, it is able to reduce the modelling error to 7.3%, which is 45.5% lower. Compared with the direct mapping with polynomial approach, the proposed method is able to reduce the modelling error by 41.7%. For a typically fast piezoelectric microano positioning system, hysteresis distortion is more significant towards modelling error than dynamic distortion. The proposed new approach should be useful in precision grinding process control.