复杂过程控制系统设计及控制策略的研究

【作者】 章铅飞；

【导师】 王海梅；

【作者基本信息】 南京理工大学 ， 控制理论与控制工程， 2012， 硕士

【摘要】 工业生产过程中,复杂过程普遍存在,这类过程具有的多变量和大时滞等特性,使得常规控制策略难以取得理想控制效果。论文以浙江中控的CS4000高级过程控制实验装置为研究对象,以JX-300XP DCS为控制系统,着重对复杂过程控制系统的设计过程及其控制策略进行研究。论文主要工作如下：(1)辨识了多个过程对象的数学模型,具体包括：运用阶跃响应曲线法分别建立了双容串级液位对象、双容耦合液位对象的数学模型；运用矩形脉冲响应曲线法建立了温度对象的数学模型。(2)设计了系统主管路流量与液位的自动选择性控制系统,研究了PID控制策略在该控制系统中的应用。针对自动选择性控制系统,论文又研究了一种基于模糊控制的PID参数自整定控制策略(简称模糊PID控制策略),仿真结果表明,该控制策略作用下的系统存在余差,通过进一步改进,采用含附加积分项的改进模糊PID控制策略,有效消除了余差。(3)经典PID控制策略虽然应用广泛,但对于大时滞对象,往往容易产生较大的超调量或者较大幅值的震荡。论文讨论了变参数PID控制策略以及双闭环逻辑控制策略在大时滞过程中的应用,这两种策略能够根据偏差的范围智能地调节控制器参数,进而调节控制作用的强弱。具有时滞的温度过程控制系统运行结果表明,上述两种策略较传统PID控制算法具有较好的效果。针对CS4000装置中因循环用水而导致的温度对象的非自衡特性,论文提出了一种改进的Smith预估控制策略,仿真结果证明了该策略的可行性。(4)设计了双容耦合液位控制系统,讨论了传统的解耦控制策略。考虑到策略的易实现性,研究了一类纯系数形式的解耦策略,系统运行结果显示了该控制策略的有效性和易实现性。更多还原

【Abstract】 During the process of industrial production, complex systems commonly exist, while most of these systems own the characteristic of multi-variables or time-delay, which lead conventional control strategy could not effectually work. The dissertation chooses CS4000 experimental equipment of process control as research object, and uses JX-300XP as control system, mainly study the design of process control system and control strategy which used to the complex process.What the dissertation did as follows:(1) Identifyed some mathematical models of process objects, inculding:using step response cure method established mathematical model of dual capacity cascade level object, and double-capacity coupling level object; using rectangular pulse response cure method established the mathematical model of temperature object.(2) Designed a system of main pipeline flow and liquid level of automatic selective control system, and studyed PID control strategy’s whitch used in the system. The dissertation studyed a self-tuning PID control strategy whoes parameters are calculated by Fuzzy control (FPID). Simulation results showed that strategies may lead the system hold residual error. And further improvement, used an improved Fuzzy PID with an additional intergration part, that the residual will eliminate effectively.(3) Although classic PID control strategy is used widely, whitch often produced large overshoot or oscillation of larger amplitude when used to the large time delay object. The dissertation discussed the application of a variable parameter PID control strategy and a double loop logic control strategy in the large time delay process. These two strategies’ control parameters adjusting by the scope of the deviation, and forther, adjusted the strength of the controller’s out. The operation result of temperature of the process control system with time delay show that these two strategies could reach batter results when compared with the traditional PID control algorithm. According to water recycling of CS4000 device, the temperature object with the characteristic of non-self-regulating, the paper presents an improved Smith predictor control strategy, whoes simulation results prove the feasibility of the strategy.(4) Designed a coupling of the two-capacity level control system, and discussed traditional decoupling control strategy’s application in the system. Consided an easy realizing of strategy, studyed a pure coefficient form of decoupling strategy, running results show the effectiveness of the control strategy and ease of achievability更多还原