DRONE TECHNOLOGIES ARE HELPING STREAMLINE CONSTRUCTION MANAGEMENT TASKS
It’s 7:30 a.m and Marty Laporte is watching her drone, a DJI Phantom 4 Pro, on its first photo mission of the day over a construction site soon to be a new Kinesiology & Wellness Center on the campus of a central California community college.
With her eyes focused intently above, Laporte holds a tablet, sun shade, radio transmitter and other gear so she can instantly take manual control of the craft if it runs into trouble on its preprogrammed route over the sites.
“So, what's up with the model airplanes?” I ask. Laporte laughs and explains she first became aware of drone technology as a geologist.
“I worked in environmental and hydrogeology for many years, managing water resources, groundwater management and remediation, wastewater management and environmental programs in general,” Laporte says. Today, she is the principal of ManageWater Consulting, Inc., a water management and technology consulting firm in Redwood City, Calif. She's also been a commercial RC pilot under the Federal Aviation Administration's Part 107 since November 2016.
“Drones are very complicated pieces of equipment. It's a flying computer, really,” she continues. “The Small Unmanned Aerial System integrates the use of GPS satellites using a remote controller on the ground that also has a little computer in it. And so, it's not something you can just pick up and roll with, but it is extremely useful technology to have in your tool kit if you need something to look at areas that are hard to access or even hazardous to access, if you need frequent views or images of that area.”
Software is Key
Don't think here of the large, fixed-wing military drones you may have seen flying in combat zone videos. Drones, in our context, are officially called Unmanned Aerial Vehicles (UAV) or Small Unmanned Aerial Systems (sUAS), and they're generally lightweight, highly maneuverable and lifted into the air by powerful electric motors driving four rotors at the end of arms mounted to a central pod. Lately, they have become de rigeur pieces of gear in the construction management and building inspection industries, as well as many others.
Because of the rapid implementation of drone technologies across many industries and the rise of the drone as a hobby item, the Federal Aviation Administration needed to step in and create rules for what was not long ago a simple, radio-controlled toy for flying around the park. Today, there are two ways to pilot a drone. First, as a hobbyist, you must register with the FAA under the Special Rule for Model Aircraft (Section 336) as a “modeler,” label your drone with a registration number, and adhere to all of the rules for hobby and recreation flights. To fly commercially under the FAA's sUAS Rule (Part 107), you must register your drone with the FAA and obtain a Remote Pilot Certificate from the FAA. Again, you must also comply will all airspace and pilot restrictions in effect under the rule.
"We have issued about 90,000 remote pilot certificates across the country," says Ian Gregor, public affairs manager for the FAA's Pacific Region, adding much of the agency's regulations for commercial drone pilots are available online. "The provisions of the rule — formally known as Part 107 — are designed to minimize risks to other aircraft and people and property on the ground."
Whether it's something like creating site map mosaics at different times during construction or facade and roof inspections or leak detection and moisture testing once construction is complete, drones are saving time and money and reducing worker exposure to construction site or building maintenance hazards on high-rise structures.
It seems, with drones, there's more to the game than simple aerial photography. As Laporte says, “You can take photos of these things, but to actually get accurate measurements, you need the software that's available using aerial imagery.”
The software used in conjunction with drones is capable of everything from programming a flight to calculating the volume of a pile of dirt on a job site. Jono Millin is co-founder of DroneDeploy in San Francisco, since 2003 a supplier of surveying and mapping software for drones being used in the construction, agriculture, roofing and other industries. He says DroneDeploy's software, “does a handful of things.”
“The three [areas] you can think about are flying, processing, and analyzing,” Millin says. “On the flying side, we have an app on the Google and Apple app stores you can download on to your iPad, iPhone, or Android phone or tablet. That [device] plugs into the remote control via a normal USB cable, like you'll charge your phone with, and that remote control is the one that comes with the drone that you'll buy off of Amazon or from Best Buy or off of one of the manufacturer's websites.”
From there, Millin says, the user can indicate on a map an area for the drone to photograph. “From there, we turn it into the specific detailed commands the drone needs to have in order to capture the right data of the right places to successfully create a 3D model of that area,” he said.
“The user will put in the boundary of the construction site and press the 'Go' button,” he says. “And we figure out how fast it should be flying, what camera parameters it should have, make sure that all the drone subsystems are in a safe state, check in with the aerospace. All of the complexities behind doing a good job, we will automate. The drone will take off automatically, capture the images automatically, come back home and land completely automatically.”
Things aren't enitrely automated and hands-off, though. Current regulations require pilots to have eyes on their drones at all times and each drone in the air requires a pilot to be ready to take over flying chores if the electronics suffer a glitch. Soon enough, however, there might come a day when a building maintenance operator will unleash a squadron of pre-programmed drones from a shed on the roof of a building, each one flying its own mission, taking its own pre-programmed photos and eventually returning to its very own landing spot and, perhaps, automatically downloading its photo data to storage where it can be retrieved, manipulated and studied later at the operator's convenience.
“That's a great vision of the future, and that's exactly what we're hoping to unlock,” Millin says. “All the technology that's required to do what you suggest does exist, the regulations are, right now, the big blocker for us to be able to do that effectively.”
Laporte says some of the science fiction-like possibilities made available by drone technology are already being realized. Consider the sewers of Barcelona, for example.
“They have very old, huge sewers — eight or 10 feet in diameter,” she says. “They send drones in to inspect where the leaks are and where they need to fix them. And that's an autonomous mission for sure because of gases being a risk. The other thing is the sensor technology is really evolving incredibly. So, you can sense gases, methane for example. In fact, I'm planning on purchasing a drone that can use an infrared camera and multispectral camera to detect leaks from water pipelines.”
We can hear a faint whistling buzz as we watch the drone fly its pre-programmed mission, a large S-shaped pattern some 280 feet above the construction site. The drone dutifully flies through the still, cool air between 36 predetermined checkpoints on its route. At each, the craft establishes a rock-solid hover for the brief moment it takes to capture a high-resolution photograph of the terrain directly below with its gimble-mounted 20 megapixel camera.
The entire flight, including a global-positioning system-assisted autonomous return to the exact spot from which it had taken off, takes about three minutes. Laporte monitors the flight's progress and autonomous return to its takeoff coordinates. The plan for this series of pictures is to use software to knit them together into a two- or three-dimensional mosaic of the entire site. She agrees with Millin, saying there's much more to it than simple mapping.
“The aerial perspective is different than a site perspective because you see the integration of parts,” she says. “For example, connections of pipes, from the air you have a bird's eye view whereas from the site you might not see those connections as well.” Laporte adds that she is set to monitor this site until the project's completion in 2019.
“You can do more frequent documentation of specific aspects of a project and then share those remotely with project managers in the office,” she says. “So, people can make decisions about things. For example, if you're digging a footing and there's something that's in the way, you can take a photograph, send it to someone so they don't have to travel. So, it's certainly less time consuming.”
Saving time is saving money. And, using drone technology, construction managers can not only monitor progress on a project, they can also easily make certain they have all the materials they need or easily assess damage and formulate repair plans without leaving their desks. Does that pile of gravel seem a little small to be 25 cubic yards? Call in the drone.
“We have a suite of tools online to do that analysis for you,” DroneDeploy's Millin says. “So, you can just select a stockpile, and we will automatically compute the volume. And typically, you know, we find from our customers that we tend to be potentially even more accurate than using a laser scanner or a typical survey method.”