SURROGATE MODELS OF PM BRUSHLESS MOTOR FOR THE PRELIMINARY DESIGN OF A MULTI-ROTOR DRONE

Multi-rotor drones see their ranges of applications and dimensions expand rapidly. Their design often involves empirical knowledge based on previous products or prototypes. For new concepts, especially with heavy loads, design models are however interesting to avoid costly iterations. This article focuses on the definition and optimization of the electric propulsion system of multi-rotor UAVs. In particular, a focus will be made on the brushless motor / gearbox / propeller assembly in order to make a comparison between devices with or without gearbox for different ranges of drone dimensions. The design constraints can be of static (hover flight) or transient (take off) type, the models can be local (distributed parameters) or global (lumped parameters). In order to support the designer, a Model-Based Design methodology is proposed in order to represent distributed parameters models (3D FEM) by low cost surrogate models dedicated for sizing. The optimization loops at both local and global levels are implemented in an open source environment.