针对不确定性离散时间系统,分析和设计了一类变结构控制器。当存在外界干扰和不确定性时,系统状态也是全局有界稳定的。一个新的切换面作为系统的输出信号被提出,特别用来设计滑模控制器。系统状态一旦进入到准滑动模态,就对设备参数变化和外界干扰显示出强的鲁棒性,因为控制器的设计完全考虑了边界层的影响。外推法被用来估计不确定离散时间系统的不确定值。两种方法均有效地消除了系统的抖振,确保了系统的稳定性,且保证了变结构控制系统良好的品质。最后,仿真结果证实了所提出方法的有效性。
The paper analyzed and designed a class of robust variable structure controllers for the uncertain discrete-time system. It showed that the system state was globally ultimately bounded in the presence of disturbance and uncertainty. Introduced a new switching surface with the system output signals. It specifically designed for discrete-time sliding mode controllers. Once the quasi-sliding mode took place, the system performance became insensitive to the plant parameter variations and external disturbances. Because the controller designs, it fully considered the effect of boundary layer. Extrapolation method was used to estimate the uncertain value of uncertain discrete time system. Two methods eliminated system chattering effectively and ensured system stability, which guaranteed good performance of variable structure control systems. Finally, simulations confirmed the effectiveness of the proposed methods.