Autonomous quadrotor flight using a vision system and accommodating frames misalignment

In this project, a Vicon motion capture/positioning system is employed to provide the pose (ground position, ground velocity and attitude) of an autonomous quadrotor. Some markers are mounted on the vehicle so that the Vicon system can track it. The markers arrangement is stored once in the Vicon system. In practice, after a few flights the markers´ configuration may be slightly altered causing offsets in the measurement of the true attitude of the quadrotor. The Vicon system itself may also measure the vehicle´s attitude with some errors in the angles due to small displacements of the cameras and a long period of use without recalibration of the whole system. Since it would be very tedious and cumbersome to recalibrate the whole vision system and making sure that the markers arrangement is still valid before every flight, a simple method has been developed to accommodate any offset in the attitude measurements. Better flight performance is obtained using the method presented.