회전 행렬을 이용한 다수 쿼드콥터의 3차원 궤적 추종 실내 비행 제어

Abstract

This paper describes an effective solution for multiple multicopters to track their 3D curved trajectories in indoor environment. The research was performed by both imulation and real flight. As aircrafts, the organization’s own developed small quadcopters were used. As a flight control computer, a popular open-platform PX4 autopilot was utilized. To provide accurate position measurement to crafts and to evaluate their flight traces accurately, a commercial motion capture system is used. For generating time-constrained curved reference trajectory, the time adjusted C-spline method developed in previous research is adopted. To represent singularity-free 3D target attitude to track 3D trajectory, rotation matrix is used instead of quaternion. Typical structures of flight controllers are compared with each other by simulation. The flight results for arbitrarily given trajectories of various shapes are shown to verify the capability of the controller. The solutions for various cases occurring in real flights are presented, including gravity compensation, battery voltage drop compensation, indoor geomagnetic field distortion, straightness improvement for linear movement by adopting speed profile, control gain scheduling, and the effect of feedforward with the reference velocity and acceleration.