基于单片机的模糊PID温度控制系统设计

摘要：模糊PID控制器实际上跟传统的PID控制器有很大联系。区别在于传统的控制器的控制前提必须是熟悉控制对象的模型结构，而模糊控制器因为它的非线性特性，所以控制性能优于传统PID控制器。对于时变系统，如果能够很好地采用模糊控制器进行调节，其控制结果的稳定性和活力性都会有改善。但是，如果调节效果不好，执行器会因为周期振荡影响使用寿命，特别是调节器是阀门的场合，就必须考虑这个问题。为了解决这个问题，出现了很多模糊控制的分析方法。本文提出的方法采用一个固定的初始域，这样相当程度上简化了模糊控制的设定问题以及实现。文中分析了振荡的原因并分析如何抑制这种振荡的各种方法，最后，还给出一种方案，通过减少隶属函数的数量以及改善解模糊化的方法缩短控制信号计算时间，有效的改善了控制的实时性。(优秀毕业设计:www.2bysj.cn)

Abstract: A fuzzy PID controllers are physically related to classical PID controller. The settings of classical controllers are based on deep common physical background. Fuzzy controller can embody better behavior comparing with classical linear PID controller because of its non linear characteristics. Well tuned fuzzy controller can be also more stable and more robust for the time varying systems. On the other hand, when the fuzzy controller is tuned badly it can exhibit limit cycle which can decrease lifetime of the actuator. This phenomenon is critical especially when the actuator is valve. Knowing about these problems, more analytical methods of tuning fuzzy controllers can be found. The method with unified universe considerably simplifies the setting and realization of fuzzy controllers. This paper tries to analyze causes of oscillations and it outlines the possibilities how to reduce them. The paper also shows solution how to reduce time needed for computation of control signal by decreasing the number of membership functions and by changing defuzzification method.

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