Adaptive Fractional-Order SMC Controller Design for Unmanned Quadrotor Helicopter Under Actuator Fault and Disturbances

This paper presented an adaptive and fractional-order sliding mode control(FOSMC) method for the unmanned quadrotor helicopter. The aircraft system includes actuator fault and external disturbances. The switching sliding mode law enables the system to reach the predefined sliding surface from arbitrary states. Then the equation control law keeps the trajectory stay over the sliding hyperplane. In order to make sure sliding motion from the arbitrary states to the surface within limited time, a novel fractional-order power switching control law is developed. System actuator failures are compensated online with adaptive control laws. The controllers are derived from the Lyapunov theory, which guarantees that the controllability and feasibility. This novel control strategy has higher tracking accuracy through the timely faults and disturbances compensation law. The presented fractional-order sliding mode scheme improves the speed of system convergence and shortens the reaching time. The adaptive strategy estimated the bounds of the disturbances and good robustness has been achieved. Simulation results shown that the presented strategy has numerous advantages in terms of attitude and position tracking.