Optimization Design and Propulsion System Sizing Methodology of Double-Layer Staggered Octocopter

Abstract

Small-scale multirotor drones often require careful consideration of many aspects including the selection of structural parameters and the propulsion system. Double-layer staggered octocopters (DLSOs) are a type of arrangement with advantages in structural layout and aerodynamic performance compared with other configurations, which can conserve structural space and restrict the aerodynamic interaction between the rotors. For the purpose of increasing thrust, reducing weight, and maximizing power efficiency, DLSOs are designed with the optimal combination of structural parameters and propulsion systems using noncustomized products. The optimization process is divided into two steps. First, utilizing the simulation results from Latin hypercube design-guided sample points, a surrogate model is established by the radial basis function (RBF)–based neural network to forecast the thrust of the staggered rotors. An optimal structural configuration of the DLSO is then obtained by applying the adaptive geometry estimation–based multiobjective evolutionary algorithm (AGE-MOEA). Second, based on an improved propulsion system sizing method, the propulsion system, including motors, electronic speed controllers (ESCs), and batteries, is further optimized using standard methods and noncustomized propulsion system product data, to minimize weight and maximize power efficiency. The optimized DLSO has greatly enhanced its total thrust and power efficiency when compared to some well-known market products.