Suboptimal Control for Nonlinear Systems with Disturbance via Integral Sliding Mode Control and Policy Iteration

In this paper, we consider a suboptimal control problem for nonlinear systems with unmatched disturbance via integral sliding mode control and policy iteration. Firstly, the unmatched disturbance is estimated by a nonlinear disturbance observer. Secondly, the integral sliding mode controller based on the disturbance estimation is designed to guarantee the reachability of the sliding-mode surface. Furthermore, the policy iteration approach based on actor-critic neural networks is used to design the suboptimal controller, which can achieve the desired performance. Finally, the effectiveness of the proposed approach is demonstrated through simulation examples.