Sliding Mode Control for Hexacopter Stabilization with Motor Failure

Abstract

This study presents a fault-tolerance approach for hexacopters with failed propulsion systems (i.e., motors and propellers) using sliding mode control theory. In this study, we use an explicit control allocation method with linear constraints for allocating the control input to redundancy actuators, as well as a new sliding model controller designed to stabilize the attitude and maintain the basic flight performance of a vehicle with a single failed motor during an outdoor autonomous flight mission. An asymmetrical motor rotation arrangement is applied in order to ensure controllability for all degrees of freedom. We verify the developed system on a real hexacopter suffering propulsion-system failure. Finally, the comparative results between the linear-quadratic-integral controller and model reference sliding mode controller are presented to evaluate the robustness of each controller against the failure of redundancy actuators.