Fault tolerance analysis of a multirotor with 6DOF

Several works have addressed the issue of obtaining a six degree of freedom (6DOF) capable multirotor. However, the capability of keeping full control in the case of a total failure in one of the rotors has not yet been analyzed. In this work, it is proven that eight is the minimum number of rotors necessary to achive 6DOF control of a multirotor, in the case of a total failure in one of them. Also, an octorotor configuration with 6DOF control capabilities in a failure situation is proposed and analyzed through numerical simulations, comparing its flight performance in a nominal and a failure case.