【作者】 李刚；

【导师】 彭辉；

【作者基本信息】 中南大学 ， 控制科学与工程， 2010， 硕士

【摘要】 液位控制作为过程控制的典型,具有大滞后、非线性、时变等特点,目前,在实际的液位控制中,多采用传统的PID控制方法。但是,对于滞后系统,难以调整合适的PID参数,很难达到理想的控制效果。模糊控制具有不依赖被控对象的数学模型、适应性强及鲁棒性好等优点,因此,适用于非线性系统。本文根据双容水箱液位控制的特点,采用模糊控制的方式,实现了双容水箱的液位控制。文章对液位控制方案及模糊控制算法的研究现状和意义进行了广泛深入的研究,综述了三容水箱及液位控制的研究现状,水箱控制策略的选择,模糊控制的研究意义,众多专家研究的方向及所取得的研究成果。而后,对三容水箱系统进行了介绍,包括其各个部件的性能指标、牛顿模块的地址分配等。本文利用组态王软件进行上位机监控系统的开发,在第三章给出了液位控制系统主监控画面及其各个子画面的开发过程,并通过“设备配置向导”定义外部设备,从而实现了上位机同下位机的实时通信。根据控制系统的需要,给出了实时曲线、历史曲线、报表的制作过程,实现了对实时数据、历史数据的查询、打印等功能,编写了控制程序,实现了液位系统的自动控制。随后,本文对模糊控制的基本原理进行介绍,具体说明模糊控制器的设计过程,给出模糊控制逻辑控制系统的组成及模糊控制器的基本结构,列出了模糊控制原理图及从模糊化到清晰化的具体实现方法。基于模糊控制不依赖实际被控对象的数学模型、鲁棒性好的特点,根据双容水箱液位控制的要求,设计模糊控制器及模糊补偿控制器,实现了双容水箱液位控制,并同传统的PID控制进行比较,从结果分析来看,模糊控制较PID控制对于复杂控制系统有更好的控制效果。最后对全文进行总结,对高级算法应用于液位控制系统进行展望,提出进一步的研究方向。更多还原

【Abstract】 As a typical case of process control, Level control has the characteristics of large delay, nonlinear, time-varying. At present, the traditional PID control method are used in the actual liquid level control, However, It is difficult to adjust the appropriate PID parameters for delay system and also difficult to achieve the desired control effect. Fuzzy control does not rely on the mathematical model of the controlled object, its adaptability and robustness are better, so it’s suitable for nonlinear systems. According to the characteristics of two-tank water level control system, we used the fuzzy control approach and achieve the two-tank liquid level automatic control.In this paper, we carried out extensive research on the status and significance of the liquid level control scheme and the fuzzy control algorithm. I summarized the research status of the three tank level control, the strategy choice of water control, the significance of fuzzy control. The experts’direction and the research results they obtained. Then, this paper introduced the three-tank system, including the performance indicators of every component and the address assignment of Newton module.In this paper, we used Kingview for the development of the PC monitoring system. It gives the development process of the pictures of the main monitor system and its sub-systems in the third chapter. We definite external devices through the "Device Configuration Wizard" and thus achieved the real-time communication between PC and lower machine. The paper given the production process of the real-time curve, the historical curve and the report according to the control system needs and thus achieved functions about query and print of real-time data and historical data. At last, we made control program to achieve automatic control of the level system.Subsequently, the basic principle of fuzzy control is introduced and the design process of fuzzy controllers is described specifically. This paper given the composition of fuzzy logic control system and the basic structure of fuzzy controller, listed the fuzzy control rule and the specific realization method from fuzzy to clarity. We designed the fuzzy controller based on the feature that Fuzzy control does not depend on the actual controlled object model and has better robustness according to the requirements of the two-tank water level control system and achieved automatic control of the two-tank water level control system. From the results of view, fuzzy control has better control effect for complex control system compared with the traditional PID control.Finally, summary the paper, and propose further research directions.更多还原