Analysis of a quadrotor in forward flight

Abstract

In general, quadrotors are designed to be stabilized about hover conditions. This allows the dynamics of the vehicle to be linearized about a single equilibrium point. Additionally, aerodynamic effects can be neglected leaving only rigid body dynamics to be modeled. While this formulation works under hover conditions, it is no longer valid when flying at high speed or in prolonged forward flight as the aerodynamics can no longer be ignored. This results in a highly nonlinear system with both aerodynamics and rigid body dynamics affecting the dynamics. In this thesis, a model of a quadrotor that takes into account both rigid-body dynamics and aerodynamics is presented. Flight testing was performed to test the validity of the this dynamic model. These flight tests were performed using a new flight space integrated into the Wright Brothers Wind Tunnel using a motion capture system. Additional flight tests were performed to gather data for a system identification of a quadrotor in forward flight using subspace methods. The results of the system identification can be used for control design for the system.