Adaptive Prescribed-Time Tracking Control for Strict-Feedback Nonlinear Systems: A Novel Full Errors Approach
针对带有复合扰动和输入约束的严格反馈非线性系统，提出一种仅需调整n个参数即可实现全误差预设时间收敛的控制方案，并通过RLC电路仿真验证了有效性。
In this article, a novel full errors prescribed-time tracking control issue is studied for strict-feedback nonlinear systems with compounded perturbations and input constraints. The conventional error constraint methods that require adjusting 2<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> design parameters to ensure all errors enter the specified accuracy within a preassigned settling time greatly increase the complexity of controller design. By blending the modified shifting function and the barrier Lyapunov function, the presented control scheme only needs to adjust <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> parameters to achieve full errors prescribed-time convergence. Besides, the dead-zone input is divided into a linear term and an interference-like term. A disturbance observer is devised to estimate and compensate the compounded perturbations, including external perturbations, fuzzy approximation errors and interference-like term, which significantly enhances the accuracy of the feedback compensation mechanism. It is proved that all signals of the closed-loop system are bounded. Finally, the availability of the proposed control strategy is testified via a simulation example of an RLC circuit.