Stabilization for a Class of Partially Observable Uncertain Fractional-Order Nonlinear Systems With Time-Varying Delays and Disturbance

This article focuses on the state feedback control design problem for a specific class of strict-feedback fractional-order nonlinear systems with unknown state time-varying delays, external disturbance, and limited observability. A state feedback control scheme is proposed based on the introduction of a reduced-order observer. The design of this control scheme utilizes Lyapunov-Krasovskii functional with static gain, leading to the development of a novel delay-independent and memoryless control strategy. The main objective is to guarantee the boundedness of all signals in the closed-loop system and ensure asymptotic stability. The effectiveness of the proposed control scheme is validated through simulation and experimental tests, demonstrating their capability to address the control challenges posed by the considered system models in neural networks, robot control and a real-time oscillator applications. Simulation and empirical results illustrate the improved performance achieved by the control strategy over two existing adaptive control schemes in terms of lower-steady-state error, faster system responsiveness and increased stability (milder oscillation) in the state responses. The proposed control scheme offers a practical way of achieving desired control objectives, providing valuable insights for researchers and practitioners in the field of control engineering.