锆钛酸铅镧陶瓷光致微位移的闭环伺服控制

利用锆钛酸铅镧(PLZT)陶瓷的光致形变效应,提出了一种光控微位移伺服系统,并通过实验对其闭环伺服控制特性进行研究。建立PLZT陶瓷光致微位移闭环伺服系统的多物理场耦合数学模型,通过静态实验对光照与光停阶段PLZT陶瓷光致形变表达式进行了参数识别。搭建了PLZT陶瓷光致微位移闭环伺服控制实验平台,基于ON-OFF控制策略,在不同光照强度下对PLZT陶瓷的光致微位移进行了闭环伺服控制实验。结果表明,通过对紫外光源施加ONOFF控制,能够实现PLZT陶瓷输出位移的闭环伺服控制。PLZT陶瓷输出位移曲线在伺服控制阶段出现超调量之后,围绕目标值上下波动。光致微位移伺服系统的响应速度、超调量与波高随着光照强度的增强而增加;在400mW/cm2光照强度下,PLZT陶瓷输出位移到达目标值的时间仅为100mW/cm2光照强度下的20%。实验结果为PLZT陶瓷在微驱动方面的工程应用奠定了基础。

Closed-loop servo control of photo-induced micro displacement of PLZT ceramic

An optical control servo system for micro displacement was proposed based on the photodeformation effect of PLZT(Lead Lanthanum Zirconate Titanate) ceramic and its closed-loop servo control characteristic was researched via an experiment method. The control equations of servo system were derived based on the mathematical model of PLZT with coupled multi-physics fields. Then, parameters in photodeformation expression of PLZT ceramic during light on/off phases were identified through the static experiment. An experimental platform for closed-loop servo control of photo-induced micro displacement of PLZT ceramic was set up and corresponding control experiments were carried out based on on-off control strategy under different light intensities. The experimental results show that the output displacement of PLZT ceramic is controlled with simple on-off method by applying ultraviolet light. After the output displacement curve of PLZT ceramic actuator reaches the target value, some different degrees of overshoot are presented, and the output displacement of PLZT ceramic actuator fluctuates around the target value. The response speed, overshoot and fluctuation height increase with the increasing light intensity. The time of the output displacement of PLZT ceramic reaching the target value under the illumination of 400 mW/cm² is only about 20 percent of that under the illuminated of 100 mW/cm² by the UV light. The results lay foundation for application of the PLZT ceramic in micro actuator engineering.