大滞后对象的预测控制仿真研究

文档编号:ZD328  文档字数:11599,页数:29

摘　　要
 
 大滞后对象在工业过程中是非常普遍的，而在过程控制领域中这是一个难点。大滞后的存在严重地影响了系统的稳定性,导致系统的超调量变大,调节时间大大加长,甚至出现振荡、发散,系统的动态品质明显变差。常规的控制算法,例如：PID控制、Smith预估控制、Dahlin算法控制,已经很难满足工业过程的要求。针对大滞后对象难控的特点，本文引入了预测控制，它具有适应性强、响应速度快、超调量小、调节时间短、鲁棒性强等特征,而且对模型的精确度要求也不高,可以很好地控制大滞后系统。本文在深入研究预测控制的发展、基本思路、控制算法的基础上，着重研究模型算法控制(MAC),并将其应用于控制大滞后对象,通过算法实现与MATLAB仿真，并与PID控制比较，验证了此种方法的有效性。由于模型算法控制大滞后对象的输出呈阶梯型，而且迟延时间越大，阶梯越宽。因此，本文又提出了一种基于预测偏差的模型算法控制（PEBMAC）,并通过算法实现与仿真，验证了它的有效性。

关键词:大滞后　　预测控制　　模型算法控制
Simulating Research on Predictive Control of a Long time-delay Target
ABSTRACT
 
 The long time-delay targets are very widespread in the industrial processes, and it is difficulty in the control domain. Its existence affects the stability of the system seriously, causes system overshoot becoming big, makes settling time become long consumedly, or even appear to oscillation and divergence. The dynamic quality of system also becomes obviously bad. The conventional control algorithms are difficult to satisfy the requests of the industrial process, such as, PID control, Smith predictor control, Dahlin algorithm control. For the characteristics of the long time-delay target being difficult to control, the predictive control is proposed in this paper, and its characters are good self-tuning ability, fast response, little overshoot, short settling time and strong robustness, etc. It has higher control precision without the necessary of precise model, so it can control the long time-delay target. On the base of the deeply study the development, basic ideas and control algorithms of the predictive control, this paper emphasizes on researching the model algorithm control (MAC), and uses it to control the long time-delay target. The simulation results show that this approach is effective by the algorithm, MATLAB simulation, and the comparison with PID control. The output of the long time-delay target which is controlled by the model algorithm control is stepped. Moreover, the longer the time-delay is, the wider the step is. Therefore, the paper proposes a model algorithm control that based on the predictive error (PEBMAC), and the results show this approach is very effective by the algorithm and simulation.

Key words : Long time-delay　　Predictive control　　Model algorithmic control
目　　录
　　
 一引言 1
 1.1大滞后对象的控制难点 1
 1.2大滞后对象的控制方法 1
 1.2.1PID控制 1
 1.2.2Smith预估控制 1
 1.2.3Dahlin算法 2
 1.3课题的提出 2
 二预测控制 3
 2.1预测控制提出的背景 3
 2.2预测控制的特点及基本思想 3
 2.3预测控制的基本原理 3
 2.3.1预测模型 4
 2.3.2滚动优化 4
 2.3.3反馈校正 4
 2.4预测控制算法 4
 2.4.1模型算法控制 4
 2.4.2动态矩阵控制 5
 2.4.3广义预测控制 5
 2.5预测控制的发展前景 5
 三模型算法控制 7
 3.1内部模型 7
 3.2反馈校正 8
 3.3参考轨迹 9
 3.4滚动优化 9
 四大滞后对象的模型算法控制 11
 4.1不含滞后对象的模型算法控制 11
 4.2大滞后对象的模型控制算法 12
 4.3算法实现与仿真分析 13
 4.3.1求内部模型 13
 4.3.2算法实现与仿真分析 13
 五基于预测偏差的模型算法控制 17
 5.1预测稳态差 17
 5.2基本原理 17
 5.3算法实现与仿真分析 18
 5.3.1求内部模型 18
 5.3.2算法实现与仿真分析 18
 六总结 21
 谢辞 22
 参考文献 23
 附录 24

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