LNC Assisted Localization and Mapping in Pipe Environment

Regular maintenance of pipelines is an important task to ensure oil transportation and other operation (sewers, nature gas). Precise localization of pipeline damage can greatly improve the efficiency of maintenance work. Since the texture similarity and illumination change of pipe, traditional local descriptors for image matching like SIFT, SURF and ORB are easy to suffer from false correspondences. As to remove the false matches, the local neighborhood constraints (LNC) that contain spatial constructs around feature points are proposed. Good correspondences are essential for the high-accuracy localization and mapping solution given the limited textures and illumination in the pipes. The LNC method is also integrated into the state-of-the-art visual SLAM system. The proposed LNC image matching method and the SLAM system are evaluated on datasets gathered from the pipe environment. Compared with other state-of-the-art methods, our LNC image matching method achieves similar or better performance in precision, recall and runtime. The SLAM system provides state estimation and map reconstruction of the pipe in real-time, and the localization error is within 1%.