Two of the most exciting developments in construction technology today are the evolution of aerial imaging using drones and the adoption of Building Information Modeling (BIM).
Both have been embraced quickly and enthusiastically in recognition of their many benefits. It is therefore only inevitable that a blending of aerial imagery and BIM would lead to an ongoing and ever-closer relationship between the two.
Drones offer highly precise mapping and analysis capabilities that begin at the initial survey stage and continue to the completion of the project. Lately, the detailed imagery captured by drones has become increasingly compatible with advanced BIM software in the form of millions of visual references called “point clouds.”
What is a point cloud? It’s a collection of data points gathered by a drone flying over a project site. Each point consists of a precise x-y-z co-ordinate within the scanned area. Assembled together, these millions of individual points create a 3D image, just as millions of water droplets form a cloud in the sky. Once an aerial scan is complete, the data points are uploaded into software to create survey-grade 3D images.
One of the purposes of BIM is to allow contractors, subcontractors, owners, authorities and other stakeholders to collaborate in real time and create computer-generated 3D models. Interfacing the point clouds with BIM software can go one step beyond, creating precise 3D-modeling and imagery of both the site and the structure under construction. Since it takes less than an hour for a drone to scan a typical site, daily updates are possible — a repeatable process simply not feasible using human labour.
The integration of precise aerial imagery therefore enhances the ability to optimize design. It also assists with such matters as permit applications and reduces costly, in-process design changes. This blending of regularly updated point clouds with BIM creates what is essentially 4D imagining — 3D plus time.
There’s more. The 4D aerial imagery created using point clouds, and its seamless integration into BIM, offers the additional potential of reducing disputes and litigation by creating highly accurate project record-keeping.
This record-keeping can prove vital. In an academic paper published in 2015 called Building Information Modeling (BIM) and Unmanned Aerial Vehicle (UAV) technologies in infrastructure construction project management and delay and disruption analysis, the authors wrote, “Methods for effective project management for the avoidance of delays or effective delay analysis and mitigation measures are essential.”
In fact, the authors believe that the record-keeping capabilities of 4D visualization are worthwhile and cost-effective for dispute-resolution reasons alone, pointing out that traditional project record-keeping consists of manual methods such as diaries, photographs and reports.
These are usually presented and monitored by updating a software program and often visualized as a Gantt chart, a type of bar chart used as a management tool to illustrate the timeline of a project. However, this can lead to uncertainties, inaccuracies, and a level of mistrust regarding the objectivity of the information.
As an alternative, the authors suggest that the accuracy and veracity of 4D imagery collected during construction could assist arbitrators or judges develop fairer resolutions in less time.
Parallel with its rapid acceptance into construction, integrating aerial imagery into BIM is being made increasingly easy and economical for industry players. Downloadable software platforms offered with various levels of sophistication, and made available through monthly subscriptions, are a starting point. Many companies around the world also offer consultancy services to assist surveyors and contractors make the integration smoother.
This continued expansion of software and support is further evidence that the marriage of BIM and drone technology is certain to be a long and happy one.
John Bleasby is a Coldwater, Ont. based freelance writer. Send comments and Inside Innovation column ideas to firstname.lastname@example.org.