针对一类离散不确定时滞系统,提出一种输出反馈变结构控制算法,该算法使系统状态无需完全可测.通过研究离散不确定时滞系统的简约型,基于LMI技术给出了滑模平面的设计方法,推导出了稳定的滑模面存在的充分条件,并将参数不确定性的影响等效为名义时滞系统的外界干扰,利用时延技术对干扰进行在线估计,从而抵消掉系统中的不确定性.采用离散趋近律的方法设计控制律,并通过仿真算例验证了所提出算法的有效性. Aiming at a class of discrete time-delay uncertain systems, a variable structure control algorithm based on output feedback is proposed, which makes the state of the system not necessary to be completely measurable. By studying the reduced form of discrete uncertain time-delay systems, Plane method, a sufficient condition for the existence of a stable sliding mode surface is deduced. The influence of parameter uncertainty is equivalent to the external disturbance of a nominal time-delay system, and the interference is estimated online by using the time delay technique to cancel out The uncertainty of the system.The control law is designed by the method of discrete approach law and the validity of the proposed algorithm is verified by simulation examples.