一类离散不确定系统自适应滑模输出反馈控制

An Adaptive Sliding Mode Output Feedback Control Strategy for a Class of Uncertain Discrete Systems

研究了离散不确定系统的滑模输出反馈控制问题.考虑离散系统的不确定为非匹配不确定,且具有未知的范数界,通过设计死区自适应律,实现了对此不确定界的在线辨识.在此设计的基础上,基于快速输出采样(multirate output sampling)原理,对系统设计了具有不确定自适应的滑模输出反馈控制器,在所设计的控制器作用下系统渐近稳定.快速输出采样是通过设置输出采样频率大于输入采样频率,经过相应的运算得到系统的当前状态信息与系统前一时刻输入信息和当前输出信息具有一定的函数关系.最后通过数值仿真验证了所设计控制器的有效性.

The problem of sliding mode output feedback control for uncertain discrete systems was investigated. The uncertainty of the discrete system was assumed to be mismatched, with an unknown norm bound. A dead-zone adaptive law was designed to identify the unknown bound online. The discrete sliding mode controller was designed based on the multirate output sampling theory. The discrete system is asymptotically stable with the proposed controller. Multirate output sampling is achieved by setting the output signals in a faster sample rate than that of the input signals, through relevant calculation, the current system states can be evaluated from the inputs at the previous time instance and the current outputs. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed control strategy.