一类开环不稳定串级控制系统的解析设计

Analytical design for a class of open-loop unstable cascade (control) systems

针对化工过程中常见的一类开环不稳定串级控制系统,提出一种新的给定值响应和负载干扰响应解耦的控制结构,从而可分别对其进行在线调节和优化.采用内模控制理论,基于鲁棒H2最优性能指标解析地推导出给定值响应控制器和抑制负载干扰的内外环扰动观测器,从而使控制系统时域响应指标可定量估计和整定.仿真实例验证了该控制结构的优越性.

A new control structure is proposed for a class of open-loop unstable cascade control systems frequently encountered in industrial and chemical processes, of which the setpoint response and the load disturbance response are decoupled from each other so that both of them can be separately regulated and optimized on line. By using the internal model control theory, the setpoint response controller and the disturbance estimators that are respectively in the inner and the outer loops for load disturbance rejection are analytically derived in terms of the robust H2 optimal performance specification. Hence the time domain response specification of the proposed control system can be quantitatively estimated and tuned. A simulation example demonstrates the superiority of the proposed control structure.