MnDOT recently entered into a contract with Collins Engineers Inc. to complete a third phase of research testing drones for bridge inspections, with a new focus on confined spaces.

This Phase 3 project is titled “Improving Quality of Bridge Inspections Using Unmanned Aircraft Systems.” Jennifer Wells, MnDOT maintenance bridge engineer, will serve as the project’s technical liaison. Barritt Lovelace, regional manager for Collins Engineering, will serve as principal investigator.

“Phase 3 will allow us to utilize a new drone specific to confined space inspections,” Wells said. “This new drone is meant to reach places the prior drones could not, which will supplement our efforts nicely.  Also, Phase 3 will include more bridge inspections in order to get a more comprehensive feel for cost and time savings.”

The increasing costs of bridge inspections are a concern for MnDOT. The use of unmanned aircraft systems (UAS) has been shown to reduce costs, improve the quality of bridge inspections, and increase safety. The UAS can deploy a wide range of imaging technologies including high definition still, video, and infrared sensors, and data can be analyzed using 3D imaging software.

MnDOT completed a small research project in 2015 to study the effectiveness of UAS technology applied to bridge safety inspections. The project team inspected four bridges at various locations throughout Minnesota and evaluated UAS’ effectiveness in improving inspection quality and inspector safety based on field results.

A second research effort demonstrated UAS imaging on the Blatnik Bridge and investigated UAS use for infrared deck surveys. Additionally, a best practices document was created to identify bridges that are best suited for UAS inspection.

It is the goal, based on this next phase of research, to implement a statewide UAS bridge inspection plan, which will identify overall cost effectiveness, improvements in quality and safety, and future funding sources for both state and local bridges.

Collins Engineering will also investigate a collision tolerant drone — the Flyability Elios — for confined space inspections.

As part of the Phase 3 project, Collins Engineering will:

• Review current Federal Aviation (FAA) rules, technical literature, owners and industry experiences, and ongoing UAS research.
• Develop bridge inspection list based on Phase II research regarding best practices. Approximately 20-25 bridges will be inspected under this contract depending on location and size.
• Develop a field work plan for the bridge inspection list. If approvals for these bridges cannot be obtained, suitable alternatives will be chosen. This field work plan will address safety concerns, FAA, and other agency requirements.
• Establish a work schedule and deliverable submission schedule.
• Establish methods of access and schedule equipment.
• Receive training on the Flyability collision tolerant drone for use in the study.
• Perform field work at the selected bridges to collect imagery and evaluate the technology to accomplish the project goals.
• Inspect known deficiencies identified during previous inspections with the use of the UAS to evaluate the ability to identify deficiencies using photos and video.
• Enter bridge inspection data in Minnesota’s Structure Information Management System (SIMS) providing element condition ratings, photos, videos, etc. based on UAS imagery and information.
• Prepare a draft report to document project activities, findings and recommendations.

The Phase 3 project is scheduled to be complete by July 2018.