Safer, faster and more efficient than manual inspections, drone inspections are taking off in many industries.
In the construction and industrial sectors, drones are changing the way work gets done, moving the needle on productivity and safety. Among the dangerous and time-consuming tasks they are helping to transform are inspections.
Through in-house drone programs and end-to-end drone service providers such as United Rentals, drones are now being used to inspect everything from bridges to elevator shafts to roofs to industrial plant towers. In many cases, they can provide a clearer view and closer inspection in a fraction of the time, without the risk to human workers.
Here are a handful of current use cases, plus a glimpse at exciting future functionalities.
Drones are being used to inspect bridges, roadways, dams, levees, even high-mast light poles and transmission lines. According to one 2018 survey, 80 percent of state highway departments surveyed are now using drones for a variety of purposes. A key advantage of UAV infrastructure inspections is that they can sometimes be done without shutting down roads or otherwise inconveniencing motorists. Inspections of fixed public infrastructure assets such as water towers can sometimes be performed by drone without needing permission to cross private property lines.
At industrial plants such as refineries and power generation plants, drones can fly near and zoom in on equipment such as flare stacks while they are operating. Ordinarily, this equipment would need to be shut down and put into safe mode for human inspection, and workers would need to use ladders, lifts, rope or rigs to access it, which creates a fall hazard. A new generation of automated industrial drones can take off, fly pre-defined routes, and land, all without a human pilot.
Adoption of United Rentals’ rooftop drone inspection offering increased nearly 100-fold between 2018 and 2019. To look for leaks, cracks and other signs of structural failure, inspectors need to climb a ladder and/or climb onto the roof, sometimes carrying specialized equipment. They may need to work at night in order to detect thermal differentials. Drones equipped with a thermal camera can do the job in a fraction of the time and can reach roof areas that may be inaccessible to humans, which can increase the quality of the inspection.
Drones have proved to be better than humans at performing certain kinds of inspections. To detect leaks in underground pipelines, a drone can take images of the ground. Software can then be used to analyze the images for dead vegetation, a telltale sign of leaks. Drones with infrared cameras are being used to create thermal imagery of pipelines; hotspots can reveal defects in insulation or leaks that are difficult for humans to see on their own.
Confined space inspections
Drones are being flown inside pipelines, boilers and other confined spaces that pose risks to humans. “It’s a much more sophisticated skill from a pilot and data analysis standpoint,” said Helge Jacobsen, vice president of operations excellence at United Rentals. For boiler inspections, “you still have to shut down the boiler, but the temperature doesn’t have to be brought down to one a human worker can tolerate,” said Jacobsen. The alternative is shutting down the boiler, waiting days for it to cool off sufficiently, and installing and removing scaffolding.
What the future may bring
Drones are still hobbled by limited battery life, which can restrict flight time, and many models don’t perform well in inclement weather and need to be grounded in snow and rain. Other barriers include the fact that in many cases, FAA guidelines limit drone operation to 400 feet above the ground.
For inspections, perhaps the biggest current hurdle is the fact that operators must have direct line of sight with the UAV. Beyond visual line of sight (BVLOS) operations require hard-to-get waivers, expensive ground-based radar and human observers. Drone companies have been amassing research on the safety of BVLOS operations and sharing it with the FAA in the hopes that it will reshape the rules.
In addition, at least one drone company is developing a collision avoidance system that may help persuade the FAA to green-light BVLOS flying. BVLOS flying would enable continuous long-distance inspection flights for pipelines and power lines, which currently can require the use of helicopters or airplanes. Skyward recently conducted a BVLOS flight test using 4G LTE to fly a drone more than 2 miles over power lines.
Other drone applications are just over the horizon. Drones that operate in different environments, such as underwater, are tantalizingly close. Underwater drones could potentially relieve commercial divers from risky inspections of structures such as underwater bridge components, underwater retaining walls and offshore oil rigs.
One day, drones may go beyond replacing humans for dangerous inspection work to replacing them for dangerous repair work. The University of Michigan recently mounted a drone with an off-the-shelf nail gun and used a modified version of open-source autopilot software to have the drone nail roof shingles all by itself.
There’s a lot in store for commercial drones just beyond visual line of sight, so to speak.
Dave Johnson is a Los Angeles-based freelance writer who has been writing about all aspects of business and technology since before there was an internet.