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Modeling And Control Of Hysteresis Nonlinearity In Piezoelectric Ceramic Acmators

Posted on:2015-03-09Degree:MasterType:Thesis
Country:ChinaCandidate:K LiFull Text:PDF
GTID:2252330431957117Subject:Control theory and control engineering
Abstract/Summary:PDF Full Text Request
Piezoelectric ceramic actuators are increasingly used in many fields because of its ultrafine resolution, fast response time, high output force and high bandwidth. However, the piezoelectric ceramic actuators suffer from the inherent hysteresis and creep nonlinearities in the piezoelectric actuators and vibration effect in the mechanical structure. These conditions affect positioning precision of piezoelectric ceramic actuators. This thesis focuses on the modeling and control for the hysteresis nonlinearity in piezoelectric ceramic actuators and the control software design. The main contents and contributions are listed as follows:1. Control software is designed to control piezoelectric ceramic actuators. And the functions of the software are described. This software can be used to send control voltage, acquisition displacement and control interval. Besides it can generate sine wave and triangular wave control signal by itself. If desired displacement and error limitation are given in close-loop control, the software can accomplish the control by itself and give accomplish time, actual displacement and control voltage. Finally the control software based on Matlab/Simulink is implemented.2. Classical Preisach model is introduced first. In practice, the Preisach operator needs to be discretized during the identification process. And the discretization level is chosen by experiment. Discretized Preisach model can be identified by input and output signals from piezoelectric ceramic actuators. The experiment results show that hysteresis can be described by discretized Preisach model. Classical Preisach model is modified to describe the main hysteresis cycle and the initial curve of piezoelectric ceramic actuators at the same time. Through experiment we can find that the modified model follows the demand.3. Firstly, the way to get inverse model of Preisach model is introduced. Then the inverse model of classical Preisach model and modified Preisach model are verified by simulate and experiment. Feedforword controllers are also designed and verified by experiment. Finally PID feedback controller is added in order to improve control performance. Through experiment we find that the composite control scheme has better performance than feedforward control algorithm alone.4. An adaptive inverse control scheme based on Preisach model is developed. The discrete Preisach model is used to describe the hysteresis nonlinear in the piezoelectric ceramic actuators. The density function of Preisach model is updated by the ratio between actual displacement and desired displacement. Experiment results show that the adaptive inverse control scheme can improve positioning precision of piezoelectric ceramic actuators.Finally a summary of the full thesis and the future works on the modeling and control of piezoelectric ceramic actuators are given.
Keywords/Search Tags:Piezoelectric ceramic actuators, Hysteresis nonlinearity, Control software, Preisach model, Composite control, Adaptive inverse control
PDF Full Text Request
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