High-order adaptive dynamic surface control for output-constrained non-linear systems based on fully actuated system approach

In this study, the authors propose a high-order adaptive dynamic surface control (HOADSC) method by using the fully actuated system-based approach for uncertain high-order strict-feedback systems (SFSs) with an output constraint. Each subsystem of the SFSs is a high-order system with a full actuation structure. In contrast to the traditional first-order state space method, the proposed control method directly treats each high-order subsystem as a whole without transforming it into a first-order system, which is a concise and efficient treatment. By introducing a series of first-order low-pass filters in each step of the design, the high-order derivatives of the virtual control law are obtained, and the complex and multiple derivation operations are transformed into simple algebraic operations. The Barrier Lyapunov function is combined to ensure that the output of the system satisfies the given constraints. And the Lyapunov theory is used to prove that all signals in the closed-loop system are ultimately uniformly bounded, and its output can accurately track the desired reference signal without violating the given constraints. The effectiveness of the proposed control method is verified by simulations of an actual manipulator system.