压电作动器建模与非线性控制技术研究

【作者】 杨涛；

【导师】 潘仲明；

【作者基本信息】 国防科学技术大学 ， 仪器科学与技术， 2005， 硕士

【摘要】 本课题来源于国家自然科学基金项目“电荷反馈式压电陶瓷精密定位及非线性控制技术”(No:10376043)。根据要求,本文研制了回滞现象小、线性化高的压电式二维微动工作平台,这种工作平台在精密工程、超精密加工等领域具有广泛的用途。该平台主要由机械弹性体、压电作动器、压电作动器驱动电路及电荷反馈回路、差动变压器测微仪和C8051F021单片机控制装置等构成。本文针对压电陶瓷存在非线性与滞后的问题,根据电荷反馈原理设计了精密功率放大电路和电荷反馈回路;建立了压电作动器的机电模型,证明了电荷反馈控制对于减小回滞现象、提高线性度有明显的作用。在此基础上,以提高工作平台的定位精度、改善其线性度为目标,采用了数字控制的方法,对PID整定、模糊控制、神经网络等算法进行了仿真实验。仿真结果表明,PID模糊控制能取得较好的控制效果。与采用电压反馈的同类工作平台相比,非线性减少60%,滞后减少95%,几乎没有爬行现象。更多还原

【Abstract】 The dissertation derives from the project“Piezoelectric platform for precision positioning using charge-feedback and nonlinear control method”supported by National Natural Science Foundation of China (authorized No. 10376043). According to the contract, a two dimensional micropositioning platform with small creep and hysteresis behavior and with high linearity was developed in this paper. The platform is widely applied in precision engineering, ultraprecision machining and et al, which consists of a mechanical elastomer, two piezoelectric actuators, two driving circuits based on charge-feedback, two linear variable differential transformers, and a numerical control device based on C8051F021.In order to deal with the nonlinearity and hysteresis of piezoceramics, a precise power amplifier circuit with charge-feedback loop was developed. And an electromechanical model of piezoelectric actuator is presented to demonstrate that charge-feedback control is prominently effective to reduce hysteresis, creep and to improve linearity. Furthermore, in order to enhance the precision and linearity of the positioning platform, simulations of several numerical control algorithms, such as PID control, fuzzy control and NN (Neuro Net) had been carried out. The results show that fuzzy PID control has better performance than the others. Compared with the piezoelectric actuator using voltage-feedback control procedure, the nonlinearity of the platform is reduced by 60%, and the hysteresis and the creep are reduced by 95% or more.更多还原