Circular Road Sign Analysis and Visual Localization Approach Based on Monocular Vision

This paper proposes a circular road sign detection and analysis method based on monocular vision, which can be used for visual localization of mobile robots. To achieve a stable and reliable real-time detection, a simple but useful circular road sign has been designed. By color-based image segmentation, edge detection, contour selection, ellipse fitting and sign verification, road sign can be detected from monocular vision. Furthermore, perspective geometry is carried out to calculate the robots position based on sign detection result and sign position. The proposed method is experimented on a robot platform. The experimental results show that the method achieves a promising performance and meets the requirement of real-time and practical situations.