毕业设计论文基于Smith预估算法则加热炉温度控制.doc

毕业设计（论文）--基于Smith预估算法则加热炉温度控制 摘 要 大迟延对象的控制一直是控制领域研究的焦点问题加热炉温度控制便属于这类复杂的控制对象传统的加热炉温度控制系统采用的是原料油出口温度同燃料油流量或同炉膛温度的串级控制但由于燃料油流量存在波动使得温度控制效果较差而且由于近年来炉膛改造炉膛容积增大使得控制系统主副被控对象均存在较大的时间滞后对于无滞后或滞后比较小的系统通常采用PID控制对于大滞后系统PID控制效果并不好需要另加补偿因此提出了Smith预估补偿控制系统而 Smith 预估算法则在模型匹配时具有好的性能指标 但是由于这种算法严重依赖模型的精确匹配 而在实际中这是很难做到的 当模型失配时Smith 预估算法就难以取得良好的控制效果因此提出了改进型Smith控制系统 本文研究的重点是设计与实现适用于燃烧控制过程的控制规律和控制算法具体讨论了纯滞后系统的Smith预估器及工程实现方法着重对这种控制算法进行了较深入的讨论并提出了一种改进型Smith预估控制器该控制器把自适应控制与史密斯预估器有机地结合起来实现对控制系统的参数自整定而且还通过仿真对设计和改进的结果进行了分析仿真实验中若采用PID控制算法系统会出现较大的超调量采用史密斯预估补偿控制没有超调量若保持控制器和模型的参数不变改变对象参数使估计模型与之失配此时史密斯预估算法出现振荡系统稳定性被破坏改进型Smith算法不仅能够保持系统的稳定而且振荡次数少收敛速度快 关键词加热炉增益自适应史密斯预估器 Abstract Large delay time has been the focus of research in the control field Furnace temperature control is belong to this complex control objectTraditional furnace temperature control system uses raw oil outlet temperature with the fuel oil flow cascade control or furnace temperature but due to volatility in fuel flow making the temperature control less effective In recent years due to the furnace chamber volume increases the control system exists in a large time lag For no or less delay the system usually adopts PID control For large delay system PID control effect is not good need additional compensation Thus puts forward Smith-predictor compensator control system The Smith-predictor in the matching model has good performance when but this algorithm heavily depends on the exact match model but it is difficult to do in practice Smith-predictor algorithm is difficult to obtain good control effect when the model mismatch Thus put forward an improved Smith-predictor control system This stduy focuses on design and realize the control laws and control algorithm that is applicable to furnace combustion control process Specific discuss the method of Smith- predictor engineering realization for pure time-delay system focusing on such a control algorithm for a more in-depth discussion and puts forward an impr