A high-precision control method for piezoelectric ceramic actuators

Abstract

A high-precision control method for a piezoelectric ceramic executor relates to the technical field of high-precision micro electro mechanical systems and servos, and overcomes the shortage of a conventional control method for the piezoelectric ceramic executor. The piezoelectric ceramic executor comprises a piezoelectric ceramic linear interference observer, a feedback controller and a linear front feed, wherein the piezoelectric ceramic linear interference observer is used for converting factors such as piezoelectric ceramic nonlinear retardation, external interference, inertia force and other unmodeled dynamics into equivalent interference in a united way and achieving observation and compensation of the equivalent interference so as to guarantee the linearity of the response characteristics of the piezoelectric ceramic executor; the feedback controller comprises an integration element and a double integral element for guaranteeing the tracking accuracy of the piezoelectric ceramic executor to an instruction; and the linear front feed is used for directly acting a position instruction onto the piezoelectric ceramic executor according to the linearized characteristics of the piezoelectric ceramic executor to improve the dynamic performance of the executor. The high-precision control method does not depend on a nonlinear retardation model, is simple and reliable, and improves the servo accuracy of the piezoelectric ceramic executor.

Description

technical field [0001] The invention relates to the fields of motion control technology and high-precision servo technology, in particular to a high-precision control method for piezoelectric ceramic actuators. Background technique [0002] Piezoelectric ceramic actuator is a kind of precision actuator, which is used for high-precision positioning and servo at micron or even nanometer level. Due to the severe nonlinear hysteresis and creep characteristics of piezoelectric ceramics, it is difficult to achieve high-precision positioning without control. Traditional methods for controlling the nonlinear characteristics of piezoelectric ceramics include model-based compensation methods, feedback control methods and compound control methods. [0003] The model-based compensation method establishes nonlinear models (such as Preisach model, Maxwell model, etc.) such as hysteresis characteristics of piezoelectric ceramics, and adds corresponding compensation quantities to the contr...

AI Technical Summary

Problems solved by technology

However, since the nonlinear characteristics of piezoelectric ceramics are not compensated, compared with actuators with higher linearity (such as motors), it is difficult to effectively guarantee the dynamic performance of the closed-loop system.

[0005] The composite control method combining traditional feedback control and feedforward control can improve the dynamic performance of the system and ensure static accuracy, but the feedforward link mostly uses nonlinear models, and the controller design is relatively complicated, which is not conducive to rapid engineering design

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