摘要
工程实际中，应用最为广泛的调节控制规律为比例、积分、微分控制，简称PID控制。PID控制自出现后，以其结构简单、稳定性好、鲁棒性好、可靠性高而广泛应用于工业过程控制领域。比例、积分、微分的组合决定了PID控制效果，决定了系统能否高效可靠地运行。常规方法整定PID控制器参数后仍然需看情况进一步调节。随着控制要求的提高，多次手动调节不满足期望，因此参数优化日益成为迫切需要。
遗传算法是一种基于生物进化理论的全局搜索优化方法。本文介绍了遗传算法的基本原理、算法框架等基本知识，并利用算法解决PID参数优化问题。通过MATLAB对一阶纯滞后系统、二阶滞后系统、三阶系统进行参数优化仿真，证明了优化后有更好的动态特性和控制效果，验证了遗传算法的有效性。
关键词：PID控制；遗传算法；参数优化；MATLAB仿真
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Abstract
In the practical engineering, the most widely used control law is proportional integral differential control,PID control for short. It has been widely used in industrial process control system because of its single algorithm, good robustness and high reliability since it appeared. The combination of PID parameters determines whether industrial equipments run efficiently and stably.The conventional methods always need further adjustments. But with the improvement of control requirements, manual regulation for many times doesn't meet expectations. So the optimization of parameters is an increasingly urgent need.
Genetic algorithm is a new optimizing searching mechod based on biology evolutionary theory. This paper introduces the basic principle of Genetic algorithm, the framework of Genetic algorithm,and applies Genetic algorithm to solve the problem of parameters optimization. The simulations on the first-order lag system, the second-order lag system, the third-order system prove the genetic algorithm better dynamic characteristics and control effects, and verify the effectiveness of the genetic algorithm.
KEY WORDS：PID control；Genetic algorithm；Parameter optimization；Matlab
simulation
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目录
0 前言 ...........................................................................................................................................1 1 绪论 ...........................................................................................................................................2 1.1 选题背景与研究现状 ..................................................................................................2 1.2 选题的目的和意义 ........................................................................................................2 1.3 研究方案和预期结果 ..................................................................................................2 1.4 论文结构 .............................................................................................................................3 2 PID控制理论 ........................................................................................................................4 2.1 PID控制 ..............................................................................................................................4 2.2 模拟PID控制 ..................................................................................................................4 2.3 数字PID控制 ..................................................................................................................5 2.3.1 位置式PID控制器 ..................................................................................................6 2.3.2 增量式PID控制器 ..................................................................................................7 2.4 PID控制的性能指标 ....................................................................................................7 3 PID参数的整定 ..................................................................................................................8 3.1常规整定方法 ...................................................................................................................8 3.1.1 理论计算整定法 .........................................................................................................8 3.1.2 工程整定法 ....................................................................................................................8 3.1.3 最佳整定法 ....................................................................................................................9 3.1.4 经验法 ..............................................................................................................................9 3.2 智能整定方法 ..................................................................................................................9 3.2.1 基于模糊控制的PID参数整定法 .................................................................10
3.2.2 基于神经网络的PID参数整定法 .................................................................10 3.2.3 基于遗传算法的 PID 参数整定法 ..............................................................10 3.2.4 基于免疫算法的 PID 参数整定法 .............................................................. 11 4 遗传算法 ...............................................................................................................................13 4.1 遗传算法的原理 ...........................................................................................................13 4.2 遗传算法的描述 ...........................................................................................................13 4.2.1 遗传算法有效性的理论基础 ............................................................................13 4.2.2 遗传算法的基本内容 ............................................................................................13 4.2.3 遗传算法的运算过程 ............................................................................................19 4.3 遗传算法的特点和应用 ...........................................................................................20 5 基于遗传算法的PID参数优化 ...............................................................................22 5.1 常规PID参数整定 ......................................................................................................22 5.2 基于遗传算法的PID参数优化介绍 ................................................................23 5.2.1 参数优化原理 ............................................................................................................23 5.2.2 参数优化步骤 ............................................................................................................23 5.3 一阶滞后系统的PID参数整定 ...........................................................................25 5.3.1 常规法整定 ..................................................................................................................25 5.3.2 基于遗传算法的PID参数优化 ......................................................................26 5.4 二阶系统滞后系统的PID参数整定.................................................................31 5.5 三阶系统的PID参数整定 ......................................................................................33 5.5.1 常规法整定 ..................................................................................................................33 5.5.2 基于遗传算法的PID参数优化 ......................................................................34
6 技术经济分析 ....................................................................................................................38 7 结论 .........................................................................................................................................39 致谢 ..............................................................................................................................................40 参考文献 ...................................................................................................................................41 附录A 译文 .............................................................................................................................43 附录B 原文 .............................................................................................................................45 附录C 程序 .............................................................................................................................48