Finite-time optimal control for uncertain strict-feedback nonlinear systems with input saturation and output constraints

In this paper, a finite-time optimal control (FTOC) strategy is proposed for output constrained uncertain nonlinear systems with input saturation. The controller adopts a feed-forward and optimal feedback control structure. The second-order command filter and the auxiliary error compensation system are designed in the feed-forward controller, which can eliminate the influence of filtering error on system performance while avoiding the singularity problem of finite-time control. A new critic weight updating law is proposed in the design of the optimal feedback controller, in which a neural network is utilized to approximate the relevant cost function. The control scheme can ensure that all signals in the optimize system are semi-global practical finite-time stable (SGPFS), and the cost function is also minimized. The effectiveness of the algorithm is validated through simulation examples.