Partial-State Decomposition-Based Control of MIMO Nonminimum Phase Nonlinear Systems With Application to a Hypersonic Vehicle Model

This article proposes a stabilizing control scheme based on partial-state decomposition to exponentially stabilize multi-input and multioutput nonminimum phase nonlinear systems in a general normal form with a general relative degree. The scheme reveals that partial-state variables can play an essential role in stabilizing the whole system. Specifically, partial-state variables are decomposed into a sum of two vector signals s and N. Then, setting s as the output vector, a new normal form is derived. For the new normal form, N and an auxiliary signal are designed to exponentially stabilize the unstable zero/internal dynamics of the auxiliary system; and the real input is designed to ensure that $s $ is exponentially stable. In particular, the zero/internal dynamics dependence on the input is fully considered in this article, and the proposed method ensures global stabilization of the closed-loop system without relying on the existence condition of Lyapunov functions. Finally, a high fidelity hypersonic vehicle model is given to show the design procedure and verify the feasibility and validity of the proposed stabilizing control scheme.