非线性积分滑模控制方法

Sliding mode control approach with nonlinear integrator

中文关键词  非线性系统  非线性积分  滑模控制  控制受限

英文关键词  nonlinear system  nonlinear integrator  sliding mode control  control constraint

中文摘要

      针对一类不确定非线性系统的滑模控制, 提出了一类具有“小误差放大, 大误差饱和”功能的光滑非线性饱和函数来改进传统的积分滑模控制, 以形成非线性积分滑模控制. 在保持传统积分滑模控制跟踪精度的同时获得更好的暂态性能. 应用Lyapunov稳定性理论和LaSalle不变性原理证明了对最终常值干扰可以完全抑制. 考虑控制受限时, 所设计的饱和控制器类似于一种PD+非线性I控制器. 最后, 仿真算例验证了所提的非线性积分滑模控制方法的有效性.

英文摘要

      A nonlinear integral sliding mode control approach is proposed for a class of uncertain nonlinear systems. To promote the performance of the traditional integral sliding mode control, this approach incorporates a new nonlinear saturation function which enhances small errors and will be saturated with large errors in shaping the tracking errors. While maintaining the tracking accuracy of the traditional integral sliding mode control, this approach provides better transient performances. Using Lyapunov stability theory and LaSalle invariance principle, we prove that the proposed approach ensures the zero steady-state error in the presence of a constant disturbance or an asymptotically constant disturbance. When the control input is constrained, the saturated controller operates like a PD controller with a nonlinear I term. Simulation example is given to demonstrate the effectiveness and robustness of the proposed approach.