不稳定时滞对象的改进内模直接控制

摘要

为解决内模控制不能直接控制不稳定对象的问题,分析系统内部稳定性,提出一种改进的二自由度内模控制器直接控制方案.利用改进的结构与经典二自由度内模结构的对应等价关系进行控制器设计;根据不同对象的特征,改进滤波器,提高系统的控制性能.该结构可以使设定值跟踪与抗负载扰动设计优化独立,具有良好的设定值跟踪和抗负载扰动能力.仿真结果表明,该方法适用于广泛的不稳定对象,具有理想的鲁棒性和控制性能.%To control the unstable processes with time delay directly,the direct control scheme based on modified internal model control was proposed by analyzing the internal stability.By analyzing the equivalence relationship between the proposed structure and the classic two degree of freedom internal model control,the controller was designed.Meanwhile,based on the process cha-racteristics,the enhanced filter was used to improve the performance.The structure allows separate optimization of load distur-bance rej ection from setpoint tracking.Illustrative examples demonstrate the satisfactory response and robustness of the pro-posed method for a variety of unstable processes.