Fractional-Order Sliding Mode Control for a Remotely Operated Vehicle With Saturated Input Constraints

A fractional-order sliding mode controller (FOSMC) is proposed for the trajectory tracking problem of a remotely operated vehicle (ROV) in the presence of external disturbance and input saturation constraints. Firstly, the ROV dynamics model is established. Secondly, based on the ROV dynamics model, an equivalent mathematical model that facilitates the design of the FOSMC is derived. Subsequently, the fractional-order differential operator is introduced into the sliding mode surface and control law of the traditional sliding mode control (SMC) algorithm. Utilizing the fast convergence properties of the fractional-order differential operator, a FOSMC was developed. Proof of the stability of the control system is given according to the Lyapunov theorem. Finally, the simulation results show that, compared to the Proportional-Integral-Derivative (PID) controller and traditional SMC, FOSMC offers superior control accuracy, strong robustness against external disturbances, and lower energy consumption under input saturation constraints.