Fixed-time prescribed performance fault-tolerant control for quad rotor UAV based on ESO

摘要

Considering the need for high precision control in the flight process of quadrotor unmanned aerial vehicle (UAV), a kind of fault-tolerant control strategy based on fixed-time prescribed performance control (FXTPPC) and extended state observer (ESO) is designed to solve the control problem of quadrotor UAV in the case of external disturbance, output error constraint and fault. Firstly, a simplified model of quadrotor UAV is established. Secondly, a double closed-loop fixed-time continuous output feedback controller based on inner loop attitude control and outer loop position control is designed. The actuator fault, sensor fault and external disturbance are estimated and compensated by ESO in real time to effectively solve the quadrotor stability control problem. Further, a FXTPPC function is introduced to convert the original constrained nonlinear system into the equivalent unconstrained nonlinear system. Finally, the stability analysis shows that the designed controller can guarantee the stability of system. Simulation results also verify the effectiveness of the proposed scheme. The tracking error can converge rapidly to the range specified by the performance function within the fixed time.