一种鲁棒直接自适应模糊控制算法

A Robust Direct Adaptive Fuzzy Control Algorithm

针对一类含有不确定项的非线性系统,提出了一种鲁棒直接自适应模糊控制算法.首先,该算法中用广义模糊双曲正切模型逼近系统的等价控制项;之后,设计了双曲正切函数的鲁棒补偿项,从而得到一种没有抖振的平滑控制输入.在系统的控制增益已知、部分已知和未知三种情况下,利用Lyapunov函数证明了采用上述控制策略可保证控制系统跟踪误差收敛到原点的一个小的邻域内,且所有的变量一致有界.仿真例子说明了该算法的有效性.

A robust direct adaptive fuzzy control scheme is proposed for a class of nonlinear systems with uncertainty. In this scheme, the equivalent control term is approximated by a fuzzy model, i.e., the generalized fuzzy hyperbolic model （GFHM）. Then, a robust compensation term is developed in form of hyperbolic tangent function to obtain a smooth control input without chattering phenomena. On conditions that the control gain of the system is known, partly known and unknown, it is proved by Lyapunov that the proposed control scheme can guarantee that the tracking errors converges at the small neighborhood of origin and that all variables involved are uniformly bounded. A simulation example is provided to demonstrate the effectiveness of the proposed control algorithm.