大滞后系统Smith预估器的控制仿真

大滞后系统Smith预估器的控制仿真一、实验目的学习借助MATLAB软件设计一个Smith预估器控制一个大滞后环节,并且了解Smith预估器参数对系统的影响。二、实验原理借助MATLAB软件我们可以轻易的模拟大滞后系统,对其进行控制仿真,Smith预估器的基本原理就是预先估计出过程在基本扰动下的动态特性,然后由预估器进行补偿,力图使被延迟了τ的被调量超前反映的调节器,使调节器提前动作,从而明显的减小超调量和加速调节过程。控制框图如下：U(s)Y(s)+--+Y’(s)+其中三、实验内容：对以下大滞后环节采取Smith预估器控制方案进行控制，其中K=2.2T=200τ=60。采用工程整定中的动态特性参数法，有一组公式如下：由此得到一组参数为：Kc=2.36Ti=134.7sTd=20.9s用MATLAB中的Simulink仿真工具箱仿真。Gc(s)KsGs(s)TransportDelay1TransportDelay2.2200s+1TransferFcn22.2200s+1TransferFcn12.2200s+1TransferFcnStepScope1sIntegrator20Gain2-K-Gain12.4Gaindu/dtDerivative１．其中KTτ变化5%，其中K=2.31T=210τ=63时。TransportDelay1TransportDelay2.31210s+1TransferFcn22.31210s+1TransferFcn12.31210s+1TransferFcnStepScope1sIntegrator20Gain2-K-Gain12.4Gaindu/dtDerivative其中KTτ变化-5%，其中K=2.09T=190τ=57时。TransportDelay1TransportDelay2.09190s+1TransferFcn22.09190s+1TransferFcn12.09190s+1TransferFcnStepScope1sIntegrator20Gain2-K-Gain12.4Gaindu/dtDerivative２．其中KTτ变化10%，其中K=2.42T=220τ=66时。TransportDelay1TransportDelay2.42220s+1TransferFcn22.42220s+1TransferFcn12.42220s+1TransferFcnStepScope1sIntegrator20Gain2-K-Gain12.4Gaindu/dtDerivative其中KTτ变化-10%，其中K=1.98T=180τ=54时。TransportDelay1TransportDelay1.98180s+1TransferFcn21.98180s+1TransferFcn11.98180s+1TransferFcnStepScope1sIntegrator20Gain2-K-Gain12.4Gaindu/dtDerivative-２．其中KTτ变化15%，其中K=2.53T=230τ=69时。TransportDelay1TransportDelay2.53230s+1TransferFcn22.53230s+1TransferFcn12.53230s+1TransferFcnStepScope1sIntegrator20Gain2-K-Gain12.4Gaindu/dtDerivative其中KTτ变化-15%，其中K=1.87T=170τ=51时。TransportDelay1TransportDelay1.87170s+1TransferFcn21.87170s+1TransferFcn11.87170s+1TransferFcnStepScope1sIntegrator20Gain2-K-Gain12.4Gaindu/dtDerivative四、实验总结：通过试验，发现Smith预估器的控制能力强，控制范围广，对大延迟系统有很强的控制能力,使被延迟了τ的被调量超前反映的调节器,使调节器提前动作,从而明显的减小超调量和加速调节过程。