CIVIL ENGINEERING LAB REPORT

Lab Report: Due October 27, 2016 Work alone on this project, NOT with your partner.

Bridge Drones Scenario

You are a civil engineer at the Minnesota Department of Transportation (MnDOT). Seeing the

potential of Unmanned Aerial Vehicles (UAVs) to aid in bridge inspections, the Minnesota

Department of Transportation has requested a demonstration project to evaluate the technology,

safety, cost, and effectiveness as a tool for bridge inspection as compared to current methods.

You have been asked for a comparison several (UAVs), or drones, used for bridge inspection.

Bridges were selected based on the following factors:

1. Cooperation of Local Agency

2. Safety

3. Varied bridge types and sizes

4. Location

5. Requirements of FAA

The four bridges are:

 Bridge 13509, Chisago County, MN – Prestressed Beam Bridge

 Bridge 448, Oronoco, MN – Concrete Arch

 Bridge 49553, Little Falls, MN - Pedestrian Steel Deck Truss

 Arcola RR Bridge, Stillwater, MN – High Steel Arch Railroad Bridge

You have compiled the following information and must present it in a lab report with tables

and pictures. You include research you have found from competitors also.

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1.0 Aeryon Skyranger [1]

For this study, an Aeyron Skyranger UAV (Skyranger) was used. This aircraft was designed

with military, public safety and commercial use in mind. The Skyranger is a very robust and

capable unit and offered several advantages for this study. The all-weather ability allowed us

to work in the rain which occurred within the first two days of field work. The Skyranger has

the ability to change payloads to utilize a standard camera, an optical zoom camera, and an

infrared camera. The Skyranger also has a very long battery life at around 50 minutes. While

the Skyranger met many of the requirements for collecting inspection data, it did not have the

ability to look upward. Therefore, a 360 degree video camera was installed on top of the

Skyranger, but due to Wi-Fi signal interference it did not perform correctly. In addition, the

Skyranger did not have the ability to fly under the bridge decks because the loss of Global

Positioning System (GPS) signal would cause the aircraft to fly vertically and return to the

launch point; which was problematic with a bridge deck overhead.

The purchase cost for the Skyranger unit is approximately $140,000.

Figure 1. Aeryon Sky Ranger

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2.0 SenseFly by Albris [5]

High Resolution Results

With Albris you can achieve sub-millimeter image resolutions using a safe, lightweight system.

Albris can capture and geotag video, still and thermal imagery, all during the same flight,

without landing to change cameras.

Focus On Work, Not On Flying

Looking to map a pre-defined site or structure? Fly an autonomous, GPS-guided mission. Or

use Alibris’s ScreenFly feature to observe structures and surfaces live, in real time. The cost is

about $80,000.

Image 2. SenseFly by Albris

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3.0 Skycatch Evolution 3, Lower cost UAVs [6]

The original field work plan included utilizing different UAV models as a comparison between

technologies. Although exemptions for several models were submitted to the FAA, none were

approved in time for the field work portion of this project phase. There are many UAVs

currently on the market with GPS and imaging capability starting at around $1000. The wide

range in price is attributed to features and length of battery life.

A lower cost UAVs battery may only last 10-20 minutes, where a higher end UAV will

typically last close to 60 minutes. Lower end models typically lack post processing software,

fail safe modes, and have lower material and build quality making them less suitable as a tool

for bridge inspection. The costs and features available on UAVs is changing rapidly as the

technology advances.

Image 3. Skycatch Evolution 3

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4.0 Current Inspection Methods

Figure 4. Example of a under bridge inspection vehicle

Figure 5. Rope access

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Figure 6. Example of the detail obtained at a difficult to access bearing location

Figure 7. Bridge inspection machine

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References

[1] Aeryon Labs Inc., http://www.aeryon.com/aeryon-skyranger, viewed September 29, 2016.

[2] Minnesota Department of Transportation, Unmanned Aerial Bridge Inspection

Demonstration Report, Offices of Transportation Management, pp 1-24, 2016.

[3] Matt Hayes, Top 5 Reasons to Use a Drone for Bridge Inspection,

http://rdoic.com/blog/top-5-reasons-to-use-a-drone-for-bridge-inspection#.V-0K1fArLIU,

November 18, 2015, viewed September 29, 2016.

[4] Rovdrone-Air and Water Industrial Inspections, http://rovdrone.eu/drone-en/industrial-

inspections/bridge-inspections/, viewed September 29, 2016.

[5] SenseFly by Albris, http://rdoic.com/products/uav/albris#.V_VyF-ArLIU,

viewed October, 2016

[6] Skycatch Evolution 3, http://www.suasnews.com/2015/12/40855/, viewed October, 2016.