Abstract: Aiming at the problem of time-delay normally exist in the Network Control System（NCS）, a new intelligent control strategy which the fuzzy adaptive algorithm and Smith Predictor algorithm combined with the conventional PID controller is proposed. The method makes full use of the Smith predictive control algorithm to control the system with time delay, at the same time use fuzzy adaptive algorithm to realize the online self-tuning of PID parameters to further improve the performance of PID controller. The simulation results show that network control system based on the new controller overcomes the defects like large overshoot of the traditional PID controller and excessive dependence on the accurate mathematical model of the conventional Smith predictor, can effectively reduce the negative effect of time-delay on the performance of the system, have desirable static and dynamic performance.

Key words: Network Control System, time-delay, fuzzy self-adaptive algorithm, Smith predictive control

摘要： 针对网络控制系统中普遍存在的时延问题，提出了一种将模糊自适应算法和Smith预估补偿算法与常规PID控制器相结合的智能控制策略。该方法充分利用了Smith预估控制算法对带时延系统的良好控制能力，同时利用模糊推理算法实现对PID参数的在线自整定，进一步改善PID控制器的性能。仿真结果表明，基于该智能控制器的网络控制系统克服了传统PID控制超调量大及常规Smith预估补偿过分依赖于被控对象精确数学模型的缺陷，可以有效降低时延对系统性能的不利影响，使被控对象具有良好的动、静态特性。

关键词: 网络控制系统, 时延, 模糊自适应, Smith预估控制