Study on vision-based hybrid tracking scheme for accurate registration in AR system

Nowadays one of the key problems that influence the performance of an AR (Augmented Reality) system is the registration error. It is common that in the current AR systems a virtual object appears to swim about as the user moves, and often does not appear to rest at the same location when viewed from different directions. In order to provide a stable tracking result for our AR application, a hybrid tracking scheme that combines the robustness of the magnetic tracking and the static accuracy of the vision based tracking is developed. The principle of the vision-based tracking is presented and the tracking accuracy of the rotation angle is studied. A magnetic tracker composed of magnetoresistive sensors and accelerometers is proposed to compensate the shortcomings of the vision-based tracking. The algorithm to calculate the position and orientation of the tracked object by combining the calculation result of the magnetic tracking and the vision-based tracking is analyzed. The setup and the experimental results of the proposed AR system are given. The results validate the feasibility of the proposed AR system.