Help! UNIVERSITY DRONE CATCHER PROJECT

[clolsonus]

Yes you're absolutely right, there is plenty of kinematics etc to go into the methodology section of my report. The report is also, like you say, in an experimental format that will require predictions/hypothesis and comparisons to real results and calculated percentage errors. I will report back here when I get further down the line with my findings.
Thank you for your interesting comments

We had a student here find a net drag modeling paper, but it was for a fishing net in water. We had him try to adapt the coefficients for air, but the student bogged down and then we decided we weren't going to drag that style of net anyway. Good luck, time flies so don't let yourself get too bogged down in any one thing, and if you can get a prototype (even super simplified and dumbed down) going right away, that can be really helpful towards informing the rest of your semester. It's really hard actually to get something working on the first try ... we have student projects all the time that pull everything together in the last 2 days ... only to discover that nothing works or they have some brutal design flaw (like they never computed the CG of the airplane and now it's physically impossible to achieve) or the crash on their first test flight and shatter everything to bits. Getting something to work and fly is actually pretty impressive when we see it. It doesn't seem like much because people around here are designing and building and flying all kinds of crazy stuff, but in the context of a student project in a semester, it's actually not all that many groups that end up being highly successful.

One of our more successful student groups in the past couple years built a foam board scale prototype (yeah!) and flew it successfully, then their final build was really awesome, they even went into bonus points land. It was a flying wing design and we set it up so you could freeze one wing servo at neutral as if it failed ... we proved it was still possible to manually navigate and even fly an approach and land with only one servo working on a flying wing... One of our grad students then took that idea and ran with it, and designed a fancy schmancy state space controller to navigate a flying wing on only one servo and even fly an approach and land (landings were rough, don't get me wrong, but proved under some circumstances we could avoid a crash or a fly-away.) He got a phd out of it, and I got to help out a bit as the test pilot.

 

[harrys]

I was thinking from the airframe. With drag saved vs dragging a net around you could probably have several launchers but if you have to retain the target that is less feasible. Are you committed to fixed wing?

I'm not currently committed to anything really, so a multi rotor is still possible. However what I'm concerned about is that it would be much like this system

which isn't really sophisticated enough for a final year university project.

 

[harrys]

We had a student here find a net drag modeling paper, but it was for a fishing net in water. We had him try to adapt the coefficients for air, but the student bogged down and then we decided we weren't going to drag that style of net anyway. Good luck, time flies so don't let yourself get too bogged down in any one thing, and if you can get a prototype (even super simplified and dumbed down) going right away, that can be really helpful towards informing the rest of your semester. It's really hard actually to get something working on the first try ... we have student projects all the time that pull everything together in the last 2 days ... only to discover that nothing works or they have some brutal design flaw (like they never computed the CG of the airplane and now it's physically impossible to achieve) or the crash on their first test flight and shatter everything to bits. Getting something to work and fly is actually pretty impressive when we see it. It doesn't seem like much because people around here are designing and building and flying all kinds of crazy stuff, but in the context of a student project in a semester, it's actually not all that many groups that end up being highly successful.

One of our more successful student groups in the past couple years built a foam board scale prototype (yeah!) and flew it successfully, then their final build was really awesome, they even went into bonus points land. It was a flying wing design and we set it up so you could freeze one wing servo at neutral as if it failed ... we proved it was still possible to manually navigate and even fly an approach and land with only one servo working on a flying wing... One of our grad students then took that idea and ran with it, and designed a fancy schmancy state space controller to navigate a flying wing on only one servo and even fly an approach and land (landings were rough, don't get me wrong, but proved under some circumstances we could avoid a crash or a fly-away.) He got a phd out of it, and I got to help out a bit as the test pilot.

Thank you, I reckon I may need some luck! That's a big concern of mine that it crashes on the first test flight delaying the project hugely but it's all a learning curve! That sounds like a very impressive project, I hope mine turns out as well as that! Thank you for your advice

 

[Hondo76251]

This is nothing against you, believe me, I love nothing more than to imagine creative solutions to problems but I am not thrilled with the fact that so many are spending so much time dwelling on a problem that is vastly over stated.

We just spent 20 years fighting and we were the only ones using drones effectively. Turns out explosives work much better when hidden, buried, or launched. I know, I've seen a few. If someone with some savvy wanted to be nefarious you would not catch them with a net... best you are going to do is catch a phantom flown by an idiot doing lookie loos... and a simple 2.4 jammer would just send it home (rth) but that's just my $0.02...

 

[Hondo76251]

That being said, I like your idea of fixed wing as I think it has a speed and durability edge over most multirotors... just the logistics of retention that are difficult...

 

[harrys]

This is nothing against you, believe me, I love nothing more than to imagine creative solutions to problems but I am not thrilled with the fact that so many are spending so much time dwelling on a problem that is vastly over stated.

We just spent 20 years fighting and we were the only ones using drones effectively. Turns out explosives work much better when hidden, buried, or launched. I know, I've seen a few. If someone with some savvy wanted to be nefarious you would not catch them with a net... best you are going to do is catch a phantom flown by an idiot doing lookie loos... and a simple 2.4 jammer would just send it home (rth) but that's just my $0.02...

Appreciate your opinion, and I'm well aware there are much better electronic solutions to this problem with signal jammers etc, however I am a mechanical engineer not an electronic engineer so I'm not a big fan of programming. My project will consist of 'moving parts' not signals. Drones like phantoms and even much cheaper drones are carrying out prison supply drops everyday and a rth wouldn't allow for prosecution. I understand my concept is quite crude and rough round the edges but I'm not trying to get a patent and make millions, I'm only trying to pass my final year project, thank you though.

 

[harrys]

That being said, I like your idea of fixed wing as I think it has a speed and durability edge over most multirotors... just the logistics of retention that are difficult...

Also longer flight times over most multirotors to my understanding

 

[Hondo76251]

Also longer flight times over most multirotors to my understanding

That's why I use them!

Now drones over prisons, there is a market. (Also something I know a bit about as I have a black sheep for a sibling)

Retaining the drone does little to aid in prosecution unless they were stupid enough to write their name on it. Odds are its drugs and a cell phone... in which case prevention via crashing it is acceptable (or even net with a parachute) but taking advantage of a fixed wings range and loiter time, following a suspect drone back to the location of launch... there's a job for a fixed wing with a good camera!

 

[harrys]

That's why I use them!

Now drones over prisons, there is a market. (Also something I know a bit about as I have a black sheep for a sibling)

Retaining the drone does little to aid in prosecution unless they were stupid enough to write their name on it. Odds are its drugs and a cell phone... in which case prevention via crashing it is acceptable (or even net with a parachute) but taking advantage of a fixed wings range and loiter time, following a suspect drone back to the location of launch... there's a job for a fixed wing with a good camera!

It's very common in the UK, and yes mostly for 'safe' payloads such as drugs and cell phones. There is the potential for forensics depending on crime severity. A good idea, I like it!

 

[Foam Folder]

If by rules you mean laws then my concept would be used, in theory, by groups such as the military, HMPS etc etc who would be allowed to disobey these rules to prevent serious consequences such as a terrorist attack. Apologies for not making this clear in my initial post

I don't think any drone flyer here would be able to handle any kind of payload that would be able harm anyone.

 

[Hondo76251]

I wouldnt completely discount a launched net, my buddies and I built one using a can cannon last year (but please dont mount one of those! Lmfao) and we used net wrap from the hay baler, it was quite effective. The beauty of taking down a drone is that you dont actually need to net it, a single string will effectively fowel a prop and remain stuck enough to hold the drone... that's why I said bolo style net (think McLeach catching the eagle in "the rescuers down under") 3 one inch PVC pipes would give 3 launched nets that could be in excess of 20' across. If the snare line was secured very near to the spar of the wing, if not on it directly, a plane could have a chance of towing a load...

Whatever you build, be sure to keep posted here, most everyone here loves cool out of the box projects!

 

[harrys]

I wouldnt completely discount a launched net, my buddies and I built one using a can cannon last year (but please dont mount one of those! Lmfao) and we used net wrap from the hay baler, it was quite effective. The beauty of taking down a drone is that you dont actually need to net it, a single string will effectively fowel a prop and remain stuck enough to hold the drone... that's why I said bolo style net (think McLeach catching the eagle in "the rescuers down under") 3 one inch PVC pipes would give 3 launched nets that could be in excess of 20' across. If the snare line was secured very near to the spar of the wing, if not on it directly, a plane could have a chance of towing a load...

Whatever you build, be sure to keep posted here, most everyone here loves cool out of the box projects!

I do quite like the idea if it was possible to mountain control of the drone after it's fouled, I'll keep it in mind and rethink. I will keep you updated!

 

[Hondo76251]

Can cannon... just fyi...