Low-Cost Ultra Wide-Angle Camera for Motion Tracking in Ship Maneuvering Experiments

Ship maneuvering experiments require a motion-tracking system to track the trajectory of the ship model. Some methods for motion tracking have proven to be reliable; however, they are relatively costly. Most studies on low-cost digital optics for motion measurement in hydrodynamic experiments were conducted on moored models with restricted translational motion. In contrast, maneuvering experiments require a measurement system for a wide trajectory area. This paper proposes a low-cost motion tracking system using Yi 4K action camera with an ultra wide-angle lens for measuring the trajectory in maneuvering experiments. The camera was calibrated in two steps using Bouguet's toolbox. For camera pose estimation, a grid pattern was arranged on the water surface of the basin. The motion of the ship model was measured based on the position of LED targets on the model, which were detected by their color in image sequences. Several maneuver experiments were carried out to investigate the accuracy of the system. The proposed method was validated against the Qualysis system in measuring turning diameter. With less than 5% error, it is classified as excellent according to the measurement acceptance criteria.