Motor failures pose a significant problem for the autonomous operation of multicopters. On the one hand the fault has to be detected and on the other hand the remaining asymmetric actuator envelope has to be fully exploited to maintain control of the vehicle. In this paper an algorithm for the online detection of such motor failures on a multicopter is derived using only inertial measurements. The effectiveness of each actuator is estimated from the forces and torques acting on the vehicle and those expected from the commanded motor thrusts. In addition, a method to completely utilize the available control space is presented. After a failure has been detected, the control allocation to the actuators is changed and the vehicle is able to continue its mission or return home and land safely. The control allocation is based on an exact variant of the redistributed pseudoinverse method and is able to fully utilize the available control space. If the desired commands are outside the physically possible control space, the proposed method automatically limits them to feasible values without distorting the direction of the commands. The proposed algorithms have been demonstrated in Hardware-in-the-Loop Simulations and by post-processing data collected during flights with a real multicopter.
展开▼
