Using Drones, Laser Scanning and Infraworks to get Design Buy-In
Learn | April 16, 2018
Have you ever wondered what it would cost to build something, but didn’t have the time or the money for an all-out engineering design?
The TrueScan team uses a combination of drones, laser scanning, and Infraworks to create 3D visuals that not only provide project managers a quicker way to evaluate the cost of a potential project but also produce the necessary videos and visuals to get key stakeholders on board.
In a recent project, the TrueScan team used these tools to collect quick, accurate data to form the basis of a preliminary engineering design and quickly understand potential costs.
Stakeholders commissioned the Mill Creek Feasibility Study to understand what would be required to construct a bike path along Mill Creek from Sharon Road to Sharon Woods in Cincinnati, Ohio. This critical multimodal connector will open up opportunities for other communities such as Evendale and Reading to construct bike paths, with Sharon Woods as the recreation destination.
The most important project variable to understand was cost. In order for various stakeholders to begin the process of soliciting funding for the bike path, it was necessary to determine an approximate amount of funding that would be needed. How do you estimate cost, without knowing exactly what will be built?
Another major concern was understanding the geometry of the proposed alignment. That means accommodating a ten-foot-wide path somewhere between the creek bed and the existing buildings, parking lots, etc. Ideally, the path would be designed to avoid impacts to property, minimize construction costs, while supporting bicycles, wheelchairs, and pedestrians alike.
The solutions to these, and other, design challenges are usually solved through traditional engineering and land surveying methods. First, a comprehensive survey is done to map the locations of man-made features such as roads, fences, and buildings. Additionally, the survey will collect topographic information, to understand the terrain: areas that are high vs. low, or flat vs. steep. Using the survey data as a base, a detailed engineering plan can be designed, and construction documents prepared. This is how detailed construction costs are typically estimated.
Since time and money were both limited, the TrueScan team developed an innovative solution combining reality capture technology and cutting-edge software. The proposed route was about one mile in length and covered in dense vegetation. The length and the brush created time-consuming and costly conditions for conventional survey methods, but great conditions for surveying using an Unmanned Aerial System (UAS), also known as a drone. Mapping with the UAS was done by flying over the project site, taking numerous high-res photos, and using software to turn the photos into a contour map. A contour map produced by a UAS may not be quite as accurate as one produced by conventional surveying, but it can be done in a fraction of the time and for a fraction of the cost. At this early planning stage, accuracy requirements can usually be relaxed.
One portion of the proposed alignment was planned to pass underneath a bridge on Sharon Road. Since the drone photos can’t see through bridges, TrueScan used a 3D laser scanner to measure the geometry underneath the bridge. Survey control points allowed the laser scan data to be merged with the UAS data to create a complete topographic surface.
Software Design Tool – Autodesk Infraworks
The final step was using Infraworks, a planning and visualization platform from Autodesk, to create visuals. Simply stated, Infraworks combines basic engineering design functions with enhanced visual graphics functions to allow designers to quickly convey the intent of their proposed design. Additionally, it also allows the designers to input real survey data (from scanners or drones) to validate the design.
The result was a preliminary design, verified with real-world data, and an amazing visualization. The total time spent on data acquisition and design was far less than any alternative approach, and the resulting video is sure to convey the intent of the design, as well as the recreational opportunity desired by the community stakeholders. Follow the link below to see the video produced by TrueScan: