Geographic mapping for small-diameter gas pipelines in a city
Geographic location of a pipeline is important information for pipeline maintenance and fault detection. Usually, the geographic location of a pipeline on the ground can be measured directly with global positioning system (GPS) technology, but it is much difficult to determine the geographic position of an inaccessible underground pipeline in a city. In this research, a new geographic mapping methodology is proposed for small-diameter gas pipelines in a city. A pipeline mapping micro robot equipped with a micro electro mechanical system (MEMS) based inertial measurement unit (IMU) and odometers is developed. The technique of motion identification and measurement is proposed based on the odometers. A new estimation approach is proposed to reconstruct robot path based on the features of a pipeline, the bending angles and the identified motion modes. The geographic location of a pipeline is obtained by the path optimization algorithm. The proposed methodology can help the partner organization obtain the 3-dimensional (3D) map of old gas pipelines in a city, facilitate the maintenance and leak position detection, so as to reduce troubles in the pipeline and avoid economic losses.