Cameras in Construction

(PHOTO: © BINARY STUDIO / ADOBE STOCK)

Cameras and imaging systems are changing construction sites. From site mapping to project tracking, cameras, drones and lasers are providing very accurate and precise information that can be harnessed to produce more efficient builds.

On March 20, three industry experts, Steve Mahaney, VDC area manager for Eastern Canada at EllisDon; Cody Nowell, construction services manager at PCL Constructors; and Steve Rollo, national BIM/ VDC manager at Graham, took part in a virtual discussion, moderated by yours truly, the editor of On-Site Magazine to share how these technologies are being used by their teams on sites throughout Canada.

And these technologies are varied, from traditional video-shooting drones to hardhat-mounted cameras and laser imaging systems that generate point clouds – and even photo-realistic 360-degree visuals. Thankfully, the panellists were up for all points of discussion.

To help illustrate the benefit of using drones on a project, Mahaney provided attendees with a special aerial look at the Centre Block Rehabilitation Project currently happening in Ottawa, with video provided by PCL EllisDon Joint Venture, the team working on the project at Parliament Hill.

“The teams use the drone data quite frequently,” he said, explaining that the images have been used by the BIM team in its modelling, as well as for logistics and planning purposes. “It’s an important asset that they continue to use on a daily basis.” He and his team at EllisDon use both drones and 360-degree imagery on a regular basis for most projects and view the use of this technology as an important part of the company’s business.

“The amount of data and how quickly you can capture it now provides our project teams with really great insight and also validates design from the consultants or the trade contractors,” he explained. “We can take that scan data and overlay it with models and see where we’re at.”

“Being able to get cameras and drones into the hands of all of our project teams, not just the mega projects, I think is something that we’ve seen a lot of advantage from,” said PCL’s Nowell. “When it comes to laser scanning, while the hardware is a little bit more expensive, I would say there are use cases, depending on the type of project.”

He says that getting a good representation of the existing geometry is very informative to his company’s BIM models, ensuring that the live site matches the model as closely as possible.

Graham’s Rollo is also a fan of drones. “We’re definitely seeing a huge uptick, especially in the last two years in Canada,” he said. “That, along with the 360 cameras, almost becomes just a natural thing. It’s not even discussed if it’s going to be used on a project anymore. It’s just part of a project kickoff checklist.”

INSIGHTS BY DRONE

Although there will still be some projects and situations where drones are not a perfect fit, they can be especially helpful to map out large sites, and to capture visuals where space can be difficult to otherwise navigate.

“On larger sites, it’s far easier to get a drone up in the air to map the site out,” explained Rollo. “If we’re doing a large stretch of road or bridge, bridge, we can get the high-level scope a lot easier than just taking pictures.”

“Here in Ottawa, we do a lot of rehabilitations. Looking at older buildings, the drone technology definitely comes into play,” added Mahaney. “At Centre Block, they use it for masonry, taking a look at that going up to the Peace Tower.” With each block expected to be rehabilitated during that project, the early look will help both with the restoration work and the rebuilding of the structures.

“The really nice thing I like about drones is being able to geo-reference things,” added Mahaney. “Being able to put a ground control point in, and then fly a survey flight, suddenly you’re providing the client with a geo-referenced map of exactly where that underground piece has gone.” Being able to reference the map years later to identify where pipe or other buried infrastructure is located is a major benefit to the contractor, and to the client, he explained.

“The nice thing about drones is that you can harness a lot of different types of data,” said Nowell. “You can use it for logistics planning, you can use it for quantity takeoffs. You can use it for inspections. There’s a lot of different use cases that you have with drones.”

“I think one of the biggest things that we leverage it for is our progress tracking and QA/QC practices, so that we can have that different visual of the big picture of the project to track how the project is going,” stated Rollo, adding yet more advantages to the use of visuals on a site. “We also leverage it pre-pour it to identify the PT cable layout… things of that nature… it’s a lot different to get it from that overhead perspective, and then tie that in and align it with the design intent, model or drawings… We use it heavily as part of our progress tracking and progress turnover packages that we present to the client afterwards.”

RISKS AND REGULATIONS

Use of drones is not without its challenges, risks and regulations, however. “The RPAS [Remotely Piloted Aircraft Systems] pilot has to be aware of what those inherent risks are,” advised Nowell. Once the risks have been assessed, a decision can be made on whether a traditional approach or the flying digital technology is best for the situation.

“There’s a perception out there that even with a sub-250-gram or smaller drone that basically anyone can just go out and fly,” said Rollo. “And while that’s true to a certain extent, there are a lot of rules.” He explained that failure to follow proper procedures, file appropriate flight plans when necessary, and encroaching into restricted airspace can result in Transport Canada shutting the flight down, and possibly issuing financial penalties. “You need to be conscious of that,” he advised.

“Client communication is another key part,” said Mahaney, explaining that not all clients would understand why a general contractor would want to fly a drone, and may be worried about their airspace security. He suggested communicating details about what information would be gathered, and how it would be gathered, including how RPAS requirements are to be safely met, can ease the client’s mind.

LASER PRECISION

While much of the discussion focused on drone technologies, panellists also spent time discussing how laser scanning is also assisting contractors work up 3D models so that they can work more effectively and efficiently.

“I think we where we see the most value is where we are recapturing the existing geometry,” said Nowell. His company used laser imaging technology to help with the build of a new 10-storey building on top of an existing parkade structure. New foundations were needed, which necessitated the cutting of openings in the slab and driving piles, but it was discovered that the as-built information was not accurate, which would have created significant problems.

“We use the laser scanner to capture that geometry, adjust the design and make the changes before the piling rig was even mobilized,” he said. “And that’s really where we see tremendous value in those applications. Yes, that laser scanner is an expensive piece of kit. But in the right application, it’s a lifesaver.”

“With rehabilitations, we like to have the laser scanner go out and do the ‘as-found’ conditions, so that we can really validate the information that we’re getting,” said Mahaney, who explained that the measurement accuracy has also helped in other ways as well.

“Just looking at the speed of the laser scanner now, you’ll get a superintendent who says, ‘Hey, I need a custom grate for this entryway, can you come scan this?’ And it’s like, ‘Yeah, that’s a 15-minute job, no problem, we’ll get you the most accurate data,’” he said. “It’s a great tool for the project teams to be able to scan data and start taking measurements.”

ACCURACY AND TRUST

Of course, that begs the questions, “Can I trust the data?” and “How do I know I have accurate and trustworthy measurements?”

“With photogrammetry… it’s this magic box. I take these photos, I put it into the magic box and magic spits out: I get these quantities, and this digital model, and this point cloud,” said Nowell. “Our teams are always so amazed with the data that we can pull from this thing, but how much do you really understand about what you’re capturing and what the outputs are? How are you verifying the accuracy of the information that you’ve captured?”

He explained that the software is so easy to use that can be easy to make mistakes, which may not be picked up right away.

“We’ve made a focus of trying to make sure that we’re training our people to understand what ‘good’ looks like, and to understand what common errors are,” he said. “If you’re turning over data that you don’t know what the accuracy is like, there’s big risks associated with that… there’s a lot that goes into making an accurate scan and capturing an accurate model that you can rely on. And it’s not just putting pictures into a software and then spitting it out.”

Of course, photos, videos and image-driven apps can also help with project tracking to ensure that project errors are caught as early as possible.

“Something we implement on almost every single job that that we’ve done, at least on the building side, is a hardhat-mounted 360-camera,” stated Rollo. “Similar to doing our drone flights for select jobs, this has been going on, I would say for a vast majority of our jobs now, to be able to capture our progress.”

The use of the camera and app leans on the daily site walk that needs to be done anyways, but it has now become a handsfree experience that they don’t even have to think about.

“And they don’t have to walk the same path every time,” he added, one of the ways that the geo-referenced data differs from the traditional methods formerly used for progress tracking.

NEXT STEPS FOR IMAGING

The fact is that imaging is changing the way that construction sites operate, and for the most part, technology is proving its value to project owners, construction managers and workers on the sites.

“The value cases are there, and they’re proven,” stated Nowell. “If you’re not there yet, you should be.”

“I think the biggest thing is that this is data that we need for our jobs anyways, and these technologies provide a very low-cost, efficiency gain to the project and are actually capturing the data accurately,” added Rollo. “Not only does it add a value benefit to the owner, but for your own internal record keeping, it’s huge value down the line, should that data need to be recalled at any given point.”

And for those who have already embraced the change, Mahaney says there are still next steps and technologies to look forward to.

“I think the next thing we have to look at is artificial intelligence,” he said. “Getting this imagery up into the cloud so that the machines can take a look at it, and we can start doing stuff like progress tracking and talking about billing and that sort of thing.” To watch the full webinar, please visit On-Site Magazine’s YouTube channel, or visiting https://youtu.be/w1BqtR_U4Oc.