Mismatched Disturbance Anti-disturbance Control of Quadrotor UAV
A flight control scheme of a quadrotor UAV in the presence of mismatched disturbances and actuator faults is investigated.A disturbance-observer-based control in combination with a non-singular terminal sliding mode control(NTSMC)is developed to achieve a composite anti-disturbance and fault-tolerant controller that provides expected perform-ance.Starting from the kinematic models of UAVs,the control-oriented model subject to actuator faults and mismatched disturbances are constructed.Firstly,two novel nonlinear disturbance observers are designed to estimate the mismatched disturbances and the actuator faults,which make the estimation errors converge to zero in finite settling time.Secondly,a NTSMC method is proposed to achieve desired tracking performance in finite time and effectively reduces the chatter.Final-ly,numerical simulations show the effectiveness and desired control performance of the proposed method.