Utilizing Drones for Culvert Inspection and Mapping

Introduction

This case study examines the innovative application of drone technology for the inspection and mapping of culverts. The primary objective of this survey was to conduct a condition assessment and map out the culvert’s route using the LiDAR payload. The study emphasizes the effectiveness of drones in collecting comprehensive data and obtaining measurements. This approach facilitated informed planning and maintenance decisions, showcasing the significant advantages of using drones in infrastructure assessment.

Culvert Outlet

Structure Information

Prior to Vertex attending site, we had limited information on access, dimensions and previous reports however, we knew where the outlet was and had been told the culvert was approximately 100m long. We also knew the dimensions at the outlet were approximately 1.8m x 2.0m . Ideally, we would have more comprehensive information than this before attending site which made this one a challenge from the get go.

Locating Access Points

Signal Repeater In Position

Using the Co-ordinates provided, Vertex operatives located the outlet of the culvert and set up a base to begin the inspection and mapping survey.

Being told the approximate length was 100m, we were confident the drone would make the distance to the inlet if the clearance stayed the same throughout. This would allow operatives on site to work out the location of the inlet.

Signal Issues

Sharp Incline and Direction change at ~40m

After completing a recce-flight, it was found the drone couldn’t get past 75m due to signal strength. This was because of a sharp elevation change and direction change at around 40m in. Our surveyors completed the condition survey up to around 70m and began LiDAR scanning the culvert with the Survey Package LiDAR. Ground Control Points were also picked up to give the pointcloud reference and check the accuracy of our model.

Using On-Site Data to Locate The Inlet

Red - Potential Location of Inlet

Using the data collected from the inlet, the LiDAR had picked up approximately 80m of the culvert which we could use to find the rough path it followed on site. Comparing the google maps location of the outlet and the LiDAR scan imported from the laptop, we could roughly mark and measure where the inlet is likely to be.

Continued Data Collection From Inlet

Location of Inlet Found

Using the approximate location, operatives where able to locate the culvert inlet and continue the survey from this location. Locating this was also important for us to be able to get ground control points down and check the accuracy of our Pointcloud from one side to the other.

Using distinctive features and historic sprayed numbers on the culvert walls, we could clearly work out where we got to from the other side, and made sure to overlap this to make sure we had 100% coverage of LiDAR and Visual Condition Survey. This would also allow for stitching the two separate pointclouds together using Faro Connect. The large jagged rocks and direction changes allow for cloud-to-cloud stitching with confidence in this environment.

Post-Processing and Analysis

When exporting the data from this job, we allocated the still images with chainage and video footage for our condition surveyors along with the RAW LiDAR data and GCP data for our Geospatial team.

RAW LiDAR Data

Still Images with Chainage

Using Faro Connect, we re-processed the pointcloud with the best parameters for this environment. We then also geo-referenced the pointcloud using the GCP’s we took on site. This gave us a pointcloud of the route of the culvert and surrounding area with co-ordinate data ready to be imported into CAD and tied in with topographical surveys above ground.

Merged and Co-ordinated Pointcloud

Conclusion

Overall, the culvert measured ~115m in length as opposed to the assumed 100m. There were also multiple areas with very little clearance and fast water flow which made for a challenging flight for our operators. The signal difficulties were overcome by using multiple access points to provide 100% coverage within the culvert.

Despite these challenges, this highlights the obvious advantages for using a drone instead of confined space entry for inspections like this. There was no one in a position of danger at any time and we were able to provide crucial information for if confined space entry is needed in the future allowing for a much safer plan of action.

Utilizing Vertex’s Confined Space Drones for Assessment and Planning on Renovation Project

Introduction

This case study explores the successful implementation of our confined space drone in the assessment and planning phase of a renovation project at a former theater in Arlington Road, Camden, London. The goal was to transform the theater into an upmarket events venue and cinema. However, accessing critical areas such as the fly tower and roof void posed significant challenges. This case study highlights how the drone enabled comprehensive data collection and accurate measurements, ultimately facilitating effective planning for the renovation works.

Challenges Faced

Inaccessibility of critical areas

ELIOS 3 Collecting Data in Roof Void

The fly tower and roof void were inaccessible on foot, making it difficult to gather essential data required for the renovation project.

Insufficient data from terrestrial scanners

Initial attempts using terrestrial scanners from accessible locations did not yield enough data for creating a comprehensive point cloud of the site.

Vertex’s Solution

We made use of our confined space drone to overcome the challenges our client encountered during the assessment and planning phase. With its compact size, robust design, and advanced flight capabilities, the Elios 3 proved to be the ideal tool for this project.

Results and Benefits

Comprehensive data collection

Live Feed From Safe Location

Our pilots successfully completed an entire survey of the site within just one hour from a safe location. By navigating through narrow and confined spaces, the drone captured detailed visual data of the inaccessible areas, including the fly tower and roof void.

Point cloud generation

Using the LiDAR unit on the confined space drone, a detailed point cloud of the site was created. This point cloud provided an accurate representation of the structure, enabling the client to visualize and analyse the building's current condition effectively.

Visual condition assessment

In addition to the point cloud, we also captured high-resolution video footage. This footage played a vital role in conducting a visual condition assessment of the site, allowing the client to identify areas requiring immediate attention and prioritize renovation works accordingly.

High Definition Video for Visual Condition Surveys

Precise measurements and planning

The accurate data collected on site enabled the client to take precise measurements of various areas within the theatre. These measurements were crucial in planning the renovation works, ensuring that the proposed designs and installations would seamlessly fit within the existing structure.

Conclusion

The implementation of the Elios 3 drone in the assessment and planning phase of the project proved to be a resounding success. By overcoming the challenges posed by inaccessible areas, the drone facilitated efficient data collection, visual condition assessment, and precise measurements. The comprehensive data and visual representations provided by our confined space drone allowed the client to plan the renovation works effectively, ensuring a seamless transformation of the former theatre into an upmarket events venue & cinema. The successful integration of drone technology showcases its potential to revolutionize the construction and renovation industry, providing efficient and cost-effective solutions for complex projects.