Abstract:
We present a backstepping-free adaptive control approach for tracking control of uncertain strict-feedback systems with guaranteed predefined-time prescribed performance. By introducing a novel predefined-time performance function to quantitatively set the constraint boundaries for tracking error and transforming the original uncertain strict feedback system into a new pseudo high order fully actuated (HOFA) system, as well as combining the fully actuated system theory for control design, the proposed method not only successfully achieves an improved prescribed performance control, but also effectively avoids the shortcomings of iterative design based on adaptive backstepping method, simplifying the controller design process. Based on the Lyapunov stability theory, it is proven that all signals in the closed-loop system are uniformly ultimately bounded, the system output can track the reference signal, and the tracking error can be steered into a prescribed precision within the pre-specified time. Finally, a direct current motor actuated robotic manipulator is considered to illustrate the effectiveness of the proposed approach.