Fault-tolerant control for a quadrotor unmanned helicopter subject to sensor faults

摘要

This paper presents an active fault-tolerant control scheme for a quadrotor unmanned helicopter with velocity sensor faults. A two-level control scheme is designed to guarantee the trajectory following of the quadrotor when there are no faults. The control scheme consists of an external-loop Proportion Differentiation (PD) control law and an internal-loop Proportion Integration Differentiation (PID) control law. A fault diagnosis unit is designed to detect and estimate sensor faults. The fault detection is achieved by using an observer-based residual generator of a Luenberger type and the fault estimation problem is solved by utilizing an augment variable observer. The asymptotical convergence property of estimation errors is proved. A fault-tolerant control law is proposed by combing the external-loop PD control law and the result of fault estimation. Finally, the experimental results demonstrate the effectiveness of the scheme.