PID-based fail-safe strategy against the break of opposite motors in quadcopters

The growing interest on service robotics with the use and exploitation of unmanned aerial vehicles has revealed important issues related to safety and fail prevention during navigation, and recent research has been devoted to understand and modeling the breaking of 1, 2 or even 3 motors. In this context, the present paper investigates the dynamics of an unmanned aerial vehicle of quadrotor type using PID controllers before a scenario of total failure in two opposite engines and analyses the existing relation between an equipment design issue and its navigation condition after such a failure. As a contribution, it is proposed and discussed from simulations a strategy to mitigate the mentioned failure by landing the quadrotor in a smoothly fashion. At last, preliminary results of a real failure scenario are shown to match simulated predictions.