Constrained Adaptive Fractional‐Order Sliding‐Mode Controller for Stabilizing the Two‐Degree‐of‐Freedom Gimbal System With Limited Field‐of‐View Sensors: Theoretical and Experimental Discussion

ABSTRACT This research outlines the development and implementation of a constrained adaptive fractional‐order sliding‐mode controller specifically designed for a two degree‐of‐freedom Gimbal system equipped with sensors that have a limited field‐of‐view (FOV) constraint. A fractional‐order sliding‐mode controller, which employs the Barrier Lyapunov function, is utilized to stabilize this system, ensuring that the state variables of the system remain within acceptable boundaries, thereby addressing the constraints posed by the sensors' restricted FOV in real‐world applications. The angular velocities of both the elevation and azimuth axes are driven towards zero through the adaptive fractional‐order sliding‐mode controller that has been meticulously designed. The design process takes into account the cross‐coupling effects between the inner and outer Gimbals, as well as the uncertainties arising from the moment's products and external disturbances. Both simulation and experimental findings confirm that the stabilizing controller, which incorporates a constrained adaptive fractional‐order sliding‐mode framework, successfully stabilizes the nonlinear two degree‐of‐freedom Gimbal system.