Comment on Wind-Tolerant, Autonomous Drones Could Cut Bridge Inspection Costs by 30%
linearchaos@lemmy.world 9 months ago
Either bridge inspectors get paid a hell of a lot less per hour than I think they do, or the company doing the drone inspections is way overcharging. One relatively inexperienced pilot could fly the full structure of the bridge throw it into point cloud software and drop off a highly detailed 3d model of every inch of the bridge to be inspected from the comfort of someone’s desk.
No OSHA, no driving a crane truck, no having to retract and re-extend the bucket around every structural element, no netting, no walkways or temporary bridges needing to be made.
When you do bridge inspection you have to be real close to the structure. And basically stationary as well. You are looking for minuscule gaps and other damages.
You can easily do a 3D map from afar but that won’t have anywhere near the resolution required.
close for a camera is just resolution. drone is there to provide an angle. This is a technical problem , not a time one.
It’s not just resolution
Its also stability/focus and speed
Get the camera with highest zoom you can and plop it in a drone and you will get shitty photos. Drones have a ton of vibrations.
“Its also stability/focus and speed” “Drones have a ton of vibrations.”
I think you’re conflating ‘drone’ with a $1000 consumer grade DJI. You can put whatever light, sensor or camera you want any one of a dozen stabilized platforms that are good up to 50 lbs. They’re still not any harder to fly, it’s still a one person job, you could make it two people and have the second person aiming and shooting you can do the work twice as fast.
“highest zoom you can” I didn’t say that, because it would be an intensely stupid statement to make.
If you want sub millimeter resolution of the entire structure, that’s doable. You want infrared? FLIR? all doable.
If you used a stabilized 50MP mirrorless with a fixed lens to take pictures from 10ft away, you could get 2.62 pixels per mm. If you reeled that in to 5ft at a time, you’d get 5.25 pixels per mm.
On a gimbal, with a stabilized lens, vibration would be a non issue. But if you want to beat that horse, you have 6 blades at 10krpm. The maximum frequency of the vibrations would be around 1000hz. (6*10000rpm/60) which means if you’re shooting faster than 1/1000 there’s no time for vibration even if it was completely un-stabilized. That’s easily doable with a light source. That said shooting at 800 would be more than adequate.
And there are cameras with higher resolution and faster sensors available. I’m just taking an upper end off the shelf Nikon at the moment to make the point.
See your way would create jobs and big business want less employees. So expensive autonomous drones it is !
mle86@feddit.de 9 months ago
I’m no expert on inspecting bridges, but I’d think that you still would need a professional inspector to do the inspecting, only that they would save the time of actually travelling out to the bridge themselves and instead could do it in their office, no?
And then there are probably things which still need to be done on site, such as non-visual inspections (ultrasound, X-Ray, Vibration testing, Tourque measuring on bolts, paint thickness,…? IDK)
linearchaos@lemmy.world 9 months ago
Not just travel time, but also climbing around on the bridge itself.
at the very least they would identify all the parts that need to be looked at in person.
The amount of time it takes a body to hand inspect every inch should be the lions share of the time. if it’s not, you need a new bridge :)
moistclump@lemmy.world 9 months ago
Visual inspection is an important starting point to determine if you need more extensive testing. You get a sense of the area, bridge type, and age of the bridge. This would be great for younger bridges that are low risk but should have a visual once over every couple years or so.
dvtt@lemmings.world 9 months ago
30% cost reduction vs current drone systems which can’t tolerate wind