Control and Performance of a Reconfigurable Multi-Copter

This paper presents a concept of a multicopter that can be reconfigured between a quadcopter, hexacopter, octocopter, and decacopter. The controls for each of the configurations are identified, and for the configurations with control redundancy, the power optimal controls are presented. A dynamic simulation model is implemented and used to compare the various configurations. The maximum useful weights of the octocopter, hexacopter, and quadcopter were 76.5%, 53.1%, and 29.7% that of the decacopter, respectively. Over a range of useful weights, the decacopter required the least power when the useful weight was greater than around 23% of its maximum, due to lower induced and profile power requirements of the lighter-loaded, slower-spinning rotors. At lower useful weights, smaller configurations required less power due to their lower empty weight. Increasing the number of rotors increased the maximum hover endurance, cruise endurance, and maximum range. Maximum moments and accelerations produced by each aircraft are also explored, with the hexacopter being the most agile at low useful weight, and the decacopter most agile at high weight. Each configuration exhibits longitudinal and lateral phugoid modes. The larger configurations had higher surge/sway and less negative damping ratios.