【摘要】 本文提出一种利用形状记忆合金(SMA)驱动性质并结合模糊逻辑算法进行结构位置控制的方法。首先,介绍利用常温下马氏体形状记忆镍钛合金(Nitinol)的驱动特性制成的位置控制装置的基本原理。采用电加热的方法改变Nitinol的温度,从而驱动控制对象发生位置变化。采用与温度变化相关的输出位移作为反馈信号,设计出基于反馈控制的自调节控制系统。其次,进行基于模糊逻辑的控制器设计。根据SMA自身的物理特性具有非线性,温度滞后,时变等特性,采用了不依赖于SMA数学模型的模糊控制系统。然后,进行数值仿真分析。在仿真前,对模糊控制模块进行编辑,根据Matlab提供的模糊逻辑编辑器对模糊控制器进行编译。最后,进行试验验证。试验在实验室中完成。试验采用马氏体Nitinol丝材,通过电加热的方法控制物块的移动位置。通过热电偶反馈Nitinol的温度信号,利用电加热控制作动器的运动,利用LVDT监测物块的位置。仿真分析和实验结果均表明,该控制器控制精度高,响应速度快,稳定性好等特点。更多还原

【Abstract】 A structure position control method that based on actuating property of shape memory alloy(SMA) and fuzzy logic algorithm was proposed in the paper.Firstly,the principle of the position control system that based on actuating property of the martensite Nitinol SMA wire was introduced.Electrically Joule heating method was used to change the temperature of the SMA wire to control the movement of the controlled object.A self-adjusting control system that based on feedback signals was designed by using the temperature related displacement output.Secondly,a fuzzy logic algorithm based controller was designed.Considering the nonlinear characteristic,temperature hysteresis and time variability of the SMA,a fuzzy logic control system which was independent on the math model was adopted.Then,a numerical analysis was conducted using Matlab software.Finally,a model test was conducted in the laboratory to validate the proposed method and the numerical analysis.In the test,a martensite Nitinol wire was used to control the movement position by Joule heating method.A thermocouple was used to instantaneously detect the temperature change of the wire and a LVDT was applied to measure the movement of the controlled object.The results of both numerical analysis and experiment showed that the developed controller has the properties of high precision,quick response and good stability.更多还原