Hardware and Software Architecture for Nonlinear Control of Multirotor Helicopters

This paper presents the design and implementation of a nonlinear control scheme for multirotor helicopters that takes first-order drag effects into account explicitly. A dynamic model including the blade flapping and induced drag forces is provided and a hierarchical nonlinear controller is presented. This controller is designed for both high-precision flights as well as robustness against model uncertainties and external disturbances. This is achieved by using saturated integrators with fast desaturation properties. The implementation of the controller on the flybox hexacopter platform is described. The hardware and software architecture of this UAV is discussed, and useful hints and insights gained during its design process are presented. Finally, experimental results and videos are reported to demonstrate the successful implementation and the performance of the overall system.