Robust Optical Spatial Localization using a Single Image Sensor

A novel 3-D spatial localization method using a single camera with temporal-difference image processing is proposed. The proposed active localization method uses a ring of light-emitting diodes embedded on the target. The diameter and the central location of the ring's image on the image sensor are used to estimate the target location using a Volterra series expansion of the target coordinates. No knowledge of the camera hardware parameters is needed. Instead, Volterra series parameters are obtained through a prior training that needs to be performed only once. The proposed method can be implemented with low computational complexity and storage. The performance of the proposed method is compared against an earlier method that relies on prior knowledge of the camera hardware parameters. The proposed method demonstrates excellent performance even when the target is located far away from the axial direction of the camera lens. The proposed method can be applied in low-power outdoor unmanned aerial vehicle localization and indoor robotic navigation.