时滞不稳定系统的串级内模控制

对于工业控制过程中的时滞不稳定过程,提出串级内模控制设计方法.为避免开环不稳定极点对系统的稳定鲁棒性和抑制扰动能力的影响,对控制器进行了稳定鲁棒性以及抑制扰动能力的分别设计,首先利用反馈方法整定内环的不稳定系统,然后设计前馈-反馈控制来抑制被控过程的扰动;最后使用内模控制方法对时滞被控过程进行串级外环控制,以达到对给定值的跟踪.仿真结果表明所提出的控制方法能很好地解决稳定鲁棒性和抑制扰动的均衡,且对于控制系统中过程变化引起的模型失配,可通过调整内模控制器的滤波器时间常数λ来提高控制系统的鲁棒性.

Series internal model control for unstable processes with time delays

Aiming at the unstable processes with time-delay systems,this paper provides a strategy with series internal model control method in order to eliminate the influences on the stable robustness and the ability to restrain disturbances caused by open-loop unstable pole.In this structure,the stable robustness and the ability to restrain disturbances are designed separately.Firstly,the inner-loop unstable system is tuned by backward method,then a forward-backward control strategy is designed to restrain the disturbance.At last,an outer-loop series control is designed using internal model control method in order to trace the set-value.The result of simulation shows that the strategy proposed can solve the problems on robust stability and restrain disturbances.Meanwhile,when mismatch occurs,the robustness can be improved by tuning the filter time constant.