Vehicle Positioning and Tracking Algorithm in the Visual Positioning System in Ship Cabin

Abstract

A large cargo ship is widely used for vehicle transporting, and it is necessary to position vehicles in the cabin. For the characteristic of large space, low height of ship cabin and large vehicle, building a multi-camera positioning system for vehicles is the optimal one. In this paper, a high accuracy vehicle positioning algorithm is proposed to locate multiple moving vehicles in the positioning system. Firstly, the conversion relationship between the pixel coordinate and the world coordinate is calculated. Zhang’s calibration method is adopted to correct the lens distortion, the images are stitched to get the complete cabin image and the height of vehicle body is calibrated. Secondly, a method for vehicle positioning and tracking is proposed. Background subtraction method is adopted to detect the preliminary vehicle position, and Spatio-Temporal Context (STC) algorithm is adopted to track the mark on the vehicle body. The experimental results show that in 2.56m*0.62m space of the simulated ship cabin, for three vehicle models with size of 0.45m*0.14m*0.15m, the horizontal positioning accuracy can reach 2cm each, less than 1%. With the proposed algorithm, multiple moving vehicles positioning with high accuracy and high precision in ship cabin can be reached.