受限的非仿射非线性系统的自适应控制

针对受限的非仿射非线性系统,结合自抗扰思想提出了非仿射系统的扩张状态观测器(ESO)设计,从而将辅助系统设计技巧拓展到了非仿射系统,然后利用反演和指令滤波器设计了自适应控制器,为受限的不确定非仿射系统提供了新的设计思路.为了补偿受限带来的影响,引入了辅助系统,它的状态被用来补偿跟踪误差.指令滤波器用来处理虚拟控制受限问题,同时获得虚拟控制导数的估计,避免了backstepping中对它的繁琐计算,扩张状态观测器被用来估计系统的未知非仿射非线性项和外部干扰.利用输入状态稳定性(ISS)分析了闭环系统的全局一致有界稳定性.最后仿真结果验证了该设计方案的有效性.

Adaptive control of non-affine nonlinear system with saturation constraint

The extended state observer (ESO) for the non-affine nonlinear system is presented based on the idea of active disturbance rejection. Thus, the auxiliary system design method is extended to the non-affine system. Next, an adaptive controller is proposed by combining the command filters and the backstepping algorithm for a class of uncertain non-affine nonlinear systems with input constraints and states constraints. This design scheme brings about a new ideal to deal with the constraint non-affine system. The auxiliary system is introduced to analyze the effect of constraints, and its states are used to design the adaptive tracking control. The command filters are adopted to accommodate the constraints on the virtual control laws and to avoid the tedious analytic computations of time derivatives of virtual control laws in the backstepping procedure. The extended states observers are used to estimate the unknown terms and disturbances. In the proposed control scheme, the global uniformly ultimate bounded stability of the closed-loop is proved by the input-to-state stability (ISS) synthesis, and the transient performance is improved with trajectory initialization. Finally, simulation studies are presented to illustrate the effectiveness of the proposed tracking controller.