限定初始状态非线性取代积分滑模算法的研究

Research of nonlinear replacement integral sliding mode algorithm at limited initial state

针对常规滑模控制算法抑制抖振的边界层方法存在稳态误差的缺点,考虑在常规滑膜面基础上加一个跟踪误差的积分项,这就是常规积分滑膜控制器。积分项的引入虽然可以减少稳态误差,补偿模型的不确定性,但是在大的初始误差条件下,大的超调和长的调节时间会使系统的暂态性能恶化甚至可能出现积分windup效应导致整个系统的不稳定,同时为了克服常规滑模控制在到达阶段不具有鲁棒性的缺点,又设计了限定初始状态非线性取代积分滑模控制器。通过仿真结果可以看出这种滑模控制器不但能够较好地削弱稳态误差和抑制抖振,而且也具有较好的鲁棒性。

Because the boundary layer method of traditional sliding mode control algorithm restrains buffeting had steady-state error, a tracking error of the integral term was added to the traditional sliding mode surface and this was the traditional integra- tion sliding mode controller. Although the introduction of the integral term could reduce the steady-state error and offset the un- certainty of model, in a large initial error condition, large overshoot and long regulation time would cause deterioration of system transient performance, Integral windup effect might even oeeured and it would lead to instability of the whole system, meanwhile in order to overcome the shortcomings that the traditional sliding mode control didn＇ t have the robustness in the reaching phase, the paper designed the nonlinear replacement integral sliding mode controller at the limited initial state. The simulation results show that this sliding mode controller not only can weakened steady-state error and restrain the buffeting well but also has a good robustness.