模糊PID算法在婴儿培养箱解耦控制中的应用

Application of fuzzy PID algorithm in decoupling control of infant incubator

婴儿培养箱温湿度控制系统存在较强的温湿度耦合关系是其产生时变性、滞后性的关键因素。本文采用前馈解耦的模糊比例-积分-微分(PID)控制方法,首先辨识得到温湿度双回路系统的系统模型,然后在控制系统中加入前馈解耦控制器,使原本相互耦合的温度、湿度变量等效为两个独立的温湿度控制子系统,最后在解耦回路中引入模糊PID控制机理,建立模糊增益控制器来增加系统的自适应性。在设定起始环境温度为28℃,起始环境相对湿度为60%RH的标况下,最后对改进后的解耦回路进行了仿真实验。由仿真的结果可知,相比传统PID解耦控制系统,模糊PID解耦控制系统的温湿度超调分别从3.2℃和10.7%减小到0.8℃和7.4%,温度和相对湿度的调节时间减小了190 s和230 s,解耦效果比较理想,双回路控制系统的稳定性及响应速度有了较大提高。

Infant incubator temperature and humidity control system has strong temperature and humidity coupling relationship,which is the key factor of its time denaturation and hysteresis.The feedforward decoupling method of fuzzy proportional-integral-differential(PID)control method,the temperature and humidity is obtained first combined with mechanism analysis and system identification system model of double circuit system,and then add feedforward decoupling controller in control system,make originally the mutual coupling of temperature,humidity variable equivalent to two independent temperature and humidity control subsystem,finally,the decoupling circuit introduced in fuzzy PID control mechanism,establish fuzzy gain controller to increase the adaptability of the system.Under the standard condition of setting the initial environment temperature as 28℃and the initial environment relative humidity as 60%RH,the improved decoupling loop is simulated.According to the simulation results,compared with the traditional PID decoupling control system,the temperature and humidity overregulation of the fuzzy PID decoupling control system decreased from 3.2℃and 10.7%RH to 0.8℃and 7.4%RH respectively,and the adjusting time of temperature and relative humidity decreased by 190s and 230 s.The decoupling effect is relatively ideal,and the stability and response speed of the double-loop control system are greatly improved.