I. Introduction
Position estimation is a classical problem in computer vision, which is to solve the spatial position of the camera by using the camera model and the geometric relationship under the given camera parameters. Target recognition and tracking [1], mobile robot navigation and positioning [2], visual guidance [3], 3D image reconstruction [4], unmanned navigation based on vision sensor, synchronous positioning and mapping, augmented reality and other practical applications [5] need high precision and real-time position estimation.