摘要:大迟延对象的控制一直是控制领域研究的焦点问题。锅炉温度控制便属于这类复杂的控制对象。传统的锅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Smith控制系统改进。7381
针对此现象,把史密斯(Smith)预估控制原理和模糊控制器参数调整方法结合起来,即在Smith预估控制系统中,利用整定模糊控制器的参数,即根据控制系统在各个阶段呈现出的不同特点来调节模糊控制器的量化和比例因子,以适应对象特性的变化。仿真研究表明,所提方法能有效克服普通模糊控制算法不适应大时滞系统控制和常规Smith算法过于依赖模型精度的缺陷,提高了普通模糊控制器对大滞后系统的控制能力。同时该算法还具有很强的鲁棒性和良好的控制品质。
关键词:史密斯预估控制;模糊控制;matlab仿真
Improvement of Smith predictor in the boiler temperature based on fuzzy control
Abstract: Large delay time has been the focus of research in the control field. Furnace temperature control is belong to this complex control object.Traditional 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.
Aiming at the long time - delay, the paper combines the Smith predictive control with fuzzy control, and utilizes to tune parameters of fuzzy controller on - line. Namely, adjusting the scale and quantity factors of fuzzy controllers according to different characteristic of system presenting in different phases. Consequently, making the controller fit the persification of object characteristic. Simulation shows that the presented method can effectively overcome limitations of common fuzzy control algorithm not fitting long time - delay system and general Smith algorithm depending on precision model excessively. At the same time, the self - adaptive fuzzy Smith control algorithm has strong robustness and better control performance.
Keywords: Smith predictive control; fuzzy control; MATLAB simulation
目录
1.绪论 1
1.1研究的背景及意义 1
1.2国内外基于锅炉温度控制的研究 1
1.3课题研究的内容 2
2.锅炉温度系统概况 4
2.1锅炉性能的主要指标 4
2.2锅炉燃烧控制系统结构及分析 4
3.模糊控制概况 7
3.1模糊控制简介 7
3.2模糊控制基础 7 基于模糊控制的锅炉温度史密斯预估器的改进:http://www.751com.cn/zidonghua/lunwen_5320.html