Development and Validation of the Rensselaer Multicopter Analysis Code (RMAC): a Physics-Based Comprehensive Modeling Tool

A comprehensive analysis tool (RMAC) is developed and validated for use on small-scale multi-rotor aircraft. RMAC can model multicopters with arbitrary rotor number, orientation, and position as a 6-DOF rigid-body dynamic system. Several induced-flow models, from momentum-theory to vortex-wake are available for rotor aerodynamic analysis, and rotor dynamics can optionally be modeled using the Hodges-Dowell equations. RMAC is capable of determining trim conditions, as well as generate linear models and provide nonlinear simulation in Simulink. Isolated rotor loads are validated against experimental data, with hover loads predicted as well as the analysis tool CAMRAD II. In forward flight, trends are captured well by RMAC. Predictions of the linear dynamics of the University of Portland Hexacopter are compared against experimental data, with adequate accuracy for the development of linear feedback controllers.