Active Fault-Tolerant Controller Based on Prescribed Performance with Finite-Time Nonsingular Terminal Sliding Mode for Quadrotor

This study presents a novel active fault-tolerant control strategy utilizing prescribed performance and finite-time nonsingular terminal sliding mode techniques for quadrotor attitude regulation under both normal and fault saturation conditions with external disturbances. The controller exhibits excellent control performance under both complete single-actuator failure and normal scenarios, which not only achieves controllable overshooting characteristics, but also takes into account the fastness and steady performance. In addition, the proposed controller exhibits significant robustness to external perturbations. First, this study establishes a rigid-body dynamics model and kinematics of the quadrotor. Then the primary axis based fault-tolerant controller is constructed through reduced attitude kinematics equations. And a prescribed performance function is introduced to constrain the primary axis tracking error within a prescribed range and limit the control input to avoid excessive control input, which is a keypoint to decrease the chattering. Subsequently, the design of the error transformation and finite-time sliding mode controller ensures that the primary axis tracking error can converge to the equilibrium point in finite time. Then the rigorous mathematical theory to demonstrate the stability and convergence of the controller is proposed. Numerical simulation results verify the superior performance of the controller in terms of dynamic performance, steady performance and robustness. Finally, this paper summarizes the main research results and points out the possible future research directions.