An Active Actuator Fault-Tolerant Control of a Quadrotor Based on Analytical Redundancy Relations

In order to maintain the performance of the control systems affected by the fault, a fault-tolerant control (FTC) method is used. This controller tries to minimize the effect of the fault by modifying or correcting the control law of the system at the time of fault occurrence, so that the system can continue its normal operation. In this paper, we present an analytical method for controlling the actuator faults in quadrotor. In this method, called analytical redundancy relations, we try to estimate the system states using the analytic relations, and therefore, we do not need an observer to estimate system states. So we can achieve the faulty system states without using the observer, and we can reconfigure or modify the control laws using these estimated states. This approach is an active FTC that can handle any kind of unforeseen faults that may affect the system. In this research, the control law of the main system in the normal operation is the sliding mode control that has a good performance in dealing with nonlinear complex dynamical system models.