串级不稳定时滞过程的内模控制器设计

Design Method of IMC Controllers for Unstable Cascade Processes with Time Delay

针对串级不稳定时滞过程研究了内模控制器的设计方法。该方法副回路采用传统内模控制,能及时快速消除内环干扰对系统整体控制性能的影响;主回路采用一种二自由度内模控制结构,将设定值跟随特性与干扰抑制特性解耦,控制器的参数整定不需要在两种特性之间折中选择,克服了传统内模控制的不足。理论分析和仿真结果表明,该方法不仅能有效减少控制器的个数,而且可使系统同时获得良好的设定值跟随特性、干扰抑制特性和鲁棒性。

A design method of internal model control （IMC） controllers for unstable cascade processes with time delay is presented. The cascade proposed structure contains two control loops, a secondary loop and a primary loop. In the secondary loop, an analytical design method is derived based on the traditional IMC, it can quickly reject the disturbance in the inner loop. In order to decouple the set-point tracking characteristic from disturbance rejection characteristic, a 2 degree of freedom （DOF） IMC structure is used in the primary loop. Then the set point tracking controller and the disturbance rejection controller can be tuned independently, which overcomes the shortage of a traditional IMC. Both theoretical analysis and simulation results demonstrate that the proposed method can reduce the number of controller effectively, meanwhile provide good performance of set-point tracking and disturbance rejection as well as robustness simultaneously.