Discrete-Time Fixed-Step Sliding Mode Control Based Model-Free Adaptive Control

This paper presents a novel discrete-time sliding mode control (DSMC) strategy integrated with model-free adaptive control (MFAC) to enhance tracking performance and robustness. Unlike traditional approaches, which focus on finite-step convergence, this study introduces a fixed-step dead-beat sliding mode control method. The proposed control framework ensures that the tracking error converges to the steady-state band within a predetermined number of steps, independent of initial conditions. By employing a switching reaching law based on the arctangent function, chattering effects are mitigated while maintaining high robustness against disturbances. Theoretical analysis establishes the boundedness and stability of the closed-loop system, and simulation results validate the effectiveness of the proposed DBSMC scheme.