GeoReferenced, UAVBased 3D Surveying System for Precision Construction

For the construction industry, compact, highly accurate and low cost mobile lidar systems are needed for acquiring the real world 3D geo-registered data required to generate the as built models of constructions used in building information modeling (BIM). This is particularly important for small modular reactors (SMRs), where BIM is needed to support planning, excavation, construction, commissioning, operation, maintenance, security, and regulatory compliance, and thereby reduce development and planning costs, improve quality, and enhance safety. While lidar has made significant inroads in providing data for civil and building information systems, today, 3D lidar measurements are mostly acquired with large, expensive fixed terrestrial laser scanners. When multiple perspectives are needed to collect non line of sight data, fixed terrestrial systems must be moved and calibrated. Mobile lidar systems offer the potential to generate geo-registered 3D points as the platform moves through a scene, enabling remote inspection of extensive areas of installation work closed off from direct visual inspection, such as complex pipework, concrete seams, and structures in hard to access locations. However, while mobile lidar systems have now been commercially available for a few years, none have the performance required of BIM. Systems with the requisite accuracy remain large. There is no low cost, ~1kgweight, soda can sized lidar sensor compatible with the handheld, unmanned air vehicle, and unmanned ground vehicle platforms needed for mobile data acquisition. GENERAL STATEMENT OF HOW THIS PROBLEM IS BEING ADDRESSED: The ocular hazard regulations, along with the size, weight, and power (SWAP) constraints of mobile unmanned platforms—added to the requirement to measure position and orientation with a very high degree of accuracy for the creation and geo-referencing of point clouds, over long ranges—has previously made LIDAR based surveys impractical for mobile lidar systems. To address the need for accurate, high resolution, compact, mobile lidar instruments, an eye safe mobile lidar system—with the geospatial position and pointing accuracy and mm scale accurate range measurements required for as built drawings—is being developed, with a SWAP consistent with small autonomous platforms. WHAT WAS DONE IN PHASE I: To address the need for mobile 3D lidar instruments, and refine SMR requirements, key industry stakeholders were consulted to detail SMR project lifecycle BIM requirements, identify data product requirements, specify interfaces to BIM databases, detail database formats, and identify industry life cycle software work flows. After working with industry stakeholders, a rigorous trade study was conducted. Then, key eye safe lidar components and subsystems were demonstrated with 10m to 1km range capabilities, mm scale resolution, and highly accurate geospatial positioning, orientation, and pointing. The design was developed of a mobile lidar, optimized for rapidly obtaining geospatially accurate 3D point clouds over large areas at long range. WHAT IS PLANNED FOR THE PHASE II PROJECT: In Phase II, a compact, lightweight lidar system optimized for acquiring the mm scale accuracy 3D point cloud data required for BIM will be developed, characterized, and demonstrated in a relevant environment. The mobile lidar will be calibrated and demonstrated capable of acquiring accurate geospatial data and interfacing to data work flow software. The capabilities of the mobile lidar will then be demonstrated on an unmanned ground vehicle (UGV) and an unmanned air vehicle (UAV). COMMERCIAL APPLICATIONS AND OTHER BENEFITS: Various end use industries incorporate BIM and civil information modeling (CIM) solutions in infrastructural development, including: water and waste water; bridges, roads, and highways; rail transit and aviation; energy generation facilities, houses and apartments; education institutes and commercial spaces; government buildings; factories and warehouses; dams; and others. The mobile lidar innovation enables new capabilities for each of these markets. The innovation in mobile lidar also has application in autonomous navigation and automated driver assistance systems, UAV mapping, and robotic navigation. KEY WORDS: Building information modeling, BIM, LADAR, laser radar, lidar, laser rangefinder, small modular reactor, SMR