Controlled Flight Model of Hybrid Multicopter for Computer Implementation

Among modern unmanned aerial vehicles, a special place is taken by hybrid multicopters, in structure of which gasoline engines are used along with electric motors to create the lifting force. Hybrid multicopters can carry a larger load for a longer time. The dynamics and control of such rotorcrafts are significantly complicated due to the combination of more powerful engine with less powerful ones, including the variability of inertial characteristics during the flight. The very limited practical experience in exploitation of such devices is the motivation for the research and development in this area. In the paper it is considered a helicopter-type multicopter with five electric motors (four plus one on the tail) and gasoline engine in a center. A mathematical description of the vehicle dynamics and kinematics is developed for the purpose of a controlled flight computer simulation. The description is counted all internal dynamic factors and is given simultaneously with respect to the inertial and body frames that simplifies the solution of the flight control problem as much as possible. For the latter, a multiloop motion control scheme is developed. The algorithms are based on the decomposition of the problem under the conditions of typical motion modes and the modal control method, which provides the desired quality of transitional processes. An all-purpose mechanism for the interaction of control algorithms for each engine is described. A typical flight program is simulated, and includes increase in flight altitude, yaw change, heading to and landing under the designated hover point. Simulation results confirmed the efficiency of the developed algorithms and determined the directions for further research. The results in the form of a mathematical model, decomposition methods and specific algorithms can be used in the process of designing a hybrid multicopter control system.