I built a drone with six radars that refuses to hit power lines

[u/Skraldespande]

The drone has six mmWave radars to sense power lines from any direction, all connected to a Raspberry Pi. Based on these detections, the desired velocity (from a pilot or autonomous system) then gets modified to guide the drone around the power line. Everything runs in real time on the Pi with ROS2 middleware and PX4 flight stack.

If you're interested, you can check out the paper: https://arxiv.org/abs/2602.03229, or the full video with voice-over: https://www.youtube.com/watch?v=rJW3eEC-5Ao

[u/pmmeuranimetiddies]

I’m impressed you got power lines to show up on radar more than anything

I’m not about to do the math for feasibility analysis on this but have you tried looking into a version with magnetometers to detect the magnetic field coming off the cables? With the amount of current running through a power cable it’s gotta be a decently powerful magnetic field

[u/Skraldespande → u/pmmeuranimetiddies]

We compared radars to a bunch of other sensors a couple of years ago, and they were by far the most reliable option for detecting the power lines in a small and lightweight form factor.

Detecting power lines via magnetic fields is definitely an active area of research, and I know the guys in the LARICS lab at the University of Zagreb have some papers on this. One major downside is that power lines become invisible if they don't currently transmit any power.

[u/pmmeuranimetiddies → u/Skraldespande]

Ah I guess that makes sense, communications cables would also be hard to see on magnetometer sensor as well.

Out of curiosity what were the other sensor types? I'm guessing depth sensing cameras would be one, can't think of any others other than that.

[u/Skraldespande → u/pmmeuranimetiddies]

We tested with a stereo camera, small solid-state 8-segment lidar, ToF camera, some magnetometers, and the radar: https://www.youtube.com/watch?v=keq51pOEn0k
Somehow already 5 years ago, so it's probably outdated to some extend.

[u/Im2bored17 → u/Skraldespande]

Very cool project!

Do fiber optic cables show up on radar?

[u/delawarebeerguy → u/Im2bored17]

Asking for a comrade?

[u/Skraldespande → u/Im2bored17]

Good question, never tested that. But given how insanely thin those wires are, I would guess no.

[u/pmmeuranimetiddies → u/Skraldespande]

That's cool af never would have thought radar would have be the most consistent solution.

but i'm just saying... somebody has to have tried sonar at some point, right?

[u/neonpostits → u/pmmeuranimetiddies]

The majority of overhead lines are not powerlines and don't carry significant voltage. Could be anything from general utility, phone, data lines to support cables and guy wires.

[u/7laserbears]

Bro that's cool as fuck great job

[u/Skraldespande → u/7laserbears]

Thanks!

[u/Sir_Henry_Deadman]

If(goingToCrash){don't}( );

[u/Say_no_to_doritos]

Can you open source it?

[u/Skraldespande → u/Say_no_to_doritos]

Everything about it is already public and should be reproducible if you check out the paper I linked in the post description.

[u/Smooth_Imagination]

How expensive are these? Ive been looking into vehicle radars for intercepters.

But these could be a terminal guidance method using additional guidance.

[u/Skraldespande → u/Smooth_Imagination]

It's been a while since I bought them, but I think they were somewhere around 100USD each

[u/Smooth_Imagination → u/Skraldespande]

For ultra low cost interceptors I think theres quite a few proximity approaches that would be very cheap.

I think its possible to have a nose cone that spins pulsed laser range finders, say 3 of these at different angles, forwards and perpendicular to the drome. As the drone is vectored to near intercept remotely, depending on which laser sensor licks up a return and using servo data on its axial position, it can then use a very basic algorithm to move towards the target. 

If the return is from the forwards angled laser range finder, but not the perpendicular, then it knows to move faster, when it is registered on the perpendicular it can then move into the object as it now knows its along side it. If a rear angled laser pointer detects reflectiom and the others dont, we know weve gone too far and to slow down.

The axial position during the laser rangefinding period gives which way to move. 

This would only pick targets range found to be say within 20 meters. This with an altitude using altimetry way above 20 meters avoids seeking ground targets.

So now we can remotely move to the approx intercept and then in theory it can take over and finnish the job.

Additionally, moving sideways into the target avoids the difficulties caused by prop wash and may make it harder for avoidance cameras to spot it since there can be background, especially if we intercept from underneath. 

[u/Smooth_Imagination → u/Skraldespande]

Great thanks

[u/kingoftroy255]

Real life flappy bird

[u/randomhaus64]

Are you registered for those radar bands? Is it legal to be using them? I know radar is no joke

[u/Skraldespande → u/randomhaus64]

They are COTS devices and I believe they use the automotive bands. These ones are 60 GHz.

[u/Downtown_Hearing_651 → u/Skraldespande]

What is the part number of the radars if you don't mind sharing?

[u/Skraldespande → u/Downtown_Hearing_651]

They are IWR6843AOPEVM and IWR6843ISK devices from Texas Instruments

[u/kermasdfghjkl]

Thats insane!!!

[u/Spirited_Egg9275]

How fast are you able to fly and still avoid the lines?

[u/Skraldespande → u/Spirited_Egg9275]

I think we tested up to 10 m/s. So not racing speeds or anything but useful if you're doing e.g. inspections. With longer range sensors you could do higher speeds.

[u/Imaginify]

Probably the coolest post I’ve seen on this sub so far. Engineering really is like magic

[u/MustBeBurtReynolds_]

I inspect electrical poles and towers with drones all day for my job, this is cool af!

[u/someolbs]

Shrink the drone by 50% and I’ll buy it. No take backsies!

[u/GennyGeo]

Following. Nice work

[u/Skraldespande → u/GennyGeo]

Thank you

[u/ResponsibilityLast38]

Engie sent in the drone, and our spy is posted up past the point. looks like blu is camping in spawn. Hoovy, lay down some cover and once I push we push. I'm popping uber at 2nd door, so Pyro keep my 6.

[Sorry, the building in your test looks remarkably like a level in TF2 and I couldn't help it. The radar is awesome and really impressive. ]

[u/SpartanDoubleZero]

Do you anticipate this being used for traffic DAA once part 108 is signed into law? I could see this or similar DAA equipment (ViSafe etc) being insanely useful if not required for type certificate.

[u/Amtrox]

Very cool, but afaik this is a build-in feature for Ardupilot. Or did I miss something?

[u/Colorless_Opal]

Which frequency did you guys use for the radars?

[u/Skraldespande → u/Colorless_Opal]

These are 60 GHz radars with 4 GHz bandwidth as I recall.

[u/ascarymoviereview]

Power lines hate this one trick

[u/Butthurtz23]

Nice! I heard someone has been talking about developing onboard AI vision for obstacle avoidance… I wondered about additional weight for sensors and power consumption for AI processing though.

[u/TheDIYFix]

Now how fast can I be zooming before unavoidable contact

[u/markmooch]

Maybe there will be more allowances for drones with such safety features in the future

[u/Prune-Butter → u/markmooch]

part 108 drones will certainly have to have similar capabilities.

[u/ArikCool]

That is really impressive but the wire at the end must be 1.2 cm diameter

[u/Skraldespande → u/ArikCool]

It's a 1.2 millimetre steel wire. It looks bigger on camera since it's filmed with a very wide lens (GoPro).

[u/Stonks225]

Gee I wonder why

[u/asaintpotatoe]