滑模变结构控制本质上是一类特殊的非线性控制，其非线性表现为控制的不连续性，这种控制策略与其它控制的不同之处在于系统的“结构”并不固定，而是可以在动态过程中根据系统当前的状态(如偏差及其各阶导数等)有目的地不断变化，迫使系统按照预定“滑动模态”的状态轨迹运动。由于滑动模态可以进行设计且与对象参数及扰动无关，这就使得变结构控制具有快速响应、对参数变化及扰动不灵敏、无需系统在线辩识， 物理实现简单等优点。(In essence, sliding mode variable structure control is a special kind of nonlinear control, whose nonlinear performance is the discontinuity of control. The difference between this control strategy and other controls is that the "structure" of the system is not fixed, but it can change purposefully in the dynamic process according to the current state of the system (such as deviation and its derivatives of each order, etc.), forcing the system to "slide" according to the preset State track motion of "dynamic mode".)