View Planning and Automated Data Acquisition for Three-Dimensional Modeling of Complex Sites

摘要

Constructing highly detailed three-dimensional (3-D) models of large complex sites using range scanners can be a time-consuming manual process. One of the main drawbacks is determining where to place the scanner to obtain complete coverage of a site. We have developed a system for automatic view planning called VuePlan. When combined with our mobile robot, AVENUE, we have a system that is capable of modeling large-scale environments with minimal human intervention throughout both the planning and acquisition phases. The system proceeds in two distinct stages. In the initial phase, the system is given a two-dimensional site footprint with which it plans a minimal set of sufficient and properly constrained covering views. We then use a 3-D laser scanner to take scans at each of these views. When this planning system is combined with our mobile robot it automatically computes and executes a tour of these viewing locations and acquires them with the robot's onboard laser scanner. These initial scans serve as an approximate 3-D model of the site. The planning software then enters a second phase in which it updates this model by using a voxel-based occupancy procedure to plan the next best view (NBV). This NBV is acquired, and further NBVs are sequentially computed and acquired until an accurate and complete 3-D model is obtained. A simulator tool that we developed has allowed us to test our entire view planning algorithm on simulated sites. We have also successfully used our two-phase system to construct precise 3-D models of real-world sites located in New York City: Uris Hall on the campus of Columbia University and Fort Jay on Governors Island.