Practical Prescribed‐Time Control for Strict‐Feedback Nonlinear Systems Subject to Sensor Faults and Input Saturation

Abstract

ABSTRACT This article proposes a novel and practical prescribed time control (PPTC) method for strict feedback nonlinear systems (SFNSs) subject to input saturation and sensor faults. This method fills the research gap in existing literature, which only addresses a single constraint (either input saturation or sensor faults) rather than their simultaneous occurrence. By constructing a novel time‐varying scaling transformation function (STF), a new practical prescribed‐time stability (PPTS) criterion is established. The designed decoupling control parameter mechanism can directly preset the upper bound of the convergence time and independently adjust the control accuracy, thus overcoming the limitations of traditional fixed‐time control (FxTC)–namely, the ambiguous correlation between control parameters and convergence time, as well as the difficulty in presetting the convergence time explicitly. Meanwhile, the proposed method circumvents the singularity problem and the defect of excessive initial control input in the prescribed time control (PdTC). The algorithm does not require an accurate mathematical model of the system's nonlinear components. Instead, it addresses unknown nonlinearity via fuzzy logic systems (FLSs) and enhances system robustness by integrating fault‐tolerant design with saturation compensation mechanisms. Stability analysis demonstrates that all signals of the closed‐loop system are bounded within the practical prescribed time, sensor faults are effectively compensated, and the tracking error is constrained within the preset range. The simulation results verify the effectiveness and superiority of the proposed scheme.