滴丸机石蜡油液位模型参考模糊自适应PID 控制.docVIP

滴丸机石蜡油液位的模型参考模糊自适应PID控制 彭彦卿1,2，庄进发1，罗键1，陈李清3 （1.厦门大学自动化系 福建 厦门 361005 2.厦门理工学院电子与电气工程系　福建 厦门 361005 3.厦门星鲨制药有限公司 福建 厦门361026）ontrol of Paraffin Oil Level in Capsule Forming Machine PENG Yan-qing 1,2 , ZHUANG Jin-fa 1 , LUO Jian1，CHEN Li-qing 3 Department of Automation, Xiamen University, Xiamen 361005, China; 2. Department of Electronic and Electrical Engineering, Xiamen University of Technology, Xiamen 361005, China; 3. Xiamen Xingsha Pharmaceutical Co. Ltd., Xiamen 361026, China. ) Abstract: The paraffin oil level control system in capsule forming machine is a nonlinear, time-variant and coupling system. Firstly, the mathematical model of the level control system is established. To handle the nonlinearity of the system and the time-variant parameters in the model, a new model reference fuzzy adaptive PID (MRFA-PID) control policy is proposed by combining the adaptive control, fuzzy control and PID control technique. The proposed method need not identify the parameters of the controlled plant. Thus, it has a very good real-time performance, and is easy to be implemented on line. Simulation results show that the proposed method is efficient to design a robust paraffin oil level control system for capsule forming machine with good dynamic character and high regulation. Even though parameters perturbations reach 20%, the closed-loop system still has satisfied dynamic performance. The effectiveness of the proposed method is also verified by the physical experiment. Key words: Paraffin oil level control; Modeling; Model reference adaptive control; Fuzzy control; PID control 滴丸机是鱼肝油生产行业生产无缝胶丸的重要的专用设备，其基本原理是以脉动的形式将药液打入液体明胶，然后进入石蜡油循环系统进行冷却，同时在胶液表面张力的作用下，形成球形胶丸．石蜡油循环系统中胶丸定型杯的石蜡油液位控制是一个非常关键的工艺条件，直接影响着胶丸的定型，液位太高或太低会造成胶丸变形，胶皮厚薄不均，在后续的工序中易发生胶丸破损现象，严重影响产品的质量和合格率．因为被控对象特性比较复杂，具有非线性、强耦合性和参数时变不确定性等特征，因此要求所设计的系统在具有很好的稳态精度和动态响应性能的同时，还应具有很好的鲁棒性． PID控制器具有结构简单、稳定性能好、可靠性高等优点，适用于被控对象参数固定，非线性不很严重的情况．但是在过程参数变化比较大的时候，PID控制器就难以取得良好的性能． 自适应控制[1]主要用于解决那些传统方法难以解决的控制对象参数在大范围变化的问题，它具备自适应能力