Registration Strategy of Handheld Scanner (HS) and Terrestrial Laser Scanner Integration for Building Utility Mapping

Currently, the need for a 3D model that represents the existing condition of a building is needed, especially for building management. While performed the 3D mapping of building utilities such as pipelines in buildings, the Terrestrial Laser Scanner (TLS) technology couldn’t cover the object in the ceiling, so Handheld Scanner (HS) was used to complete the scanned objects. The purpose of this article is conducting the process of mapping between HS and TLS for building pipelines. The integration between two different sensor resolutions and sensor scan coverage requires a separate strategy to generate 3D models for pipeline objects in building. The use of specific target and 3D transformation method could do the registration between two set of point clouds which was obtained by two different technologies. The target object, such as spherical object which is usually used as a tie point between scan results in the registration process, cannot be recorded by HS. The specific targets were pasted on the pipelines in order to be captured by the HS. The specific targets become tie point in the registration process. Meanwhile, the registration process using the Iterative Closest Point (ICP) algorithm cannot be carried out because the two scan results do not meet the overlap percentage standard, so that the 3D transformation would be used in registration process. The result is that the registration accuracy is 0.062 m.