Hi all,
Does anyone know of any redundancy solutions for the PIXHAWK/APM2.5+? I'm flying a very expensive and heavy quadrotor that can do some serious damage. I want to reduce the risk of a single point controller failure to the best of my ability.
Thanks!
Tony
Replies
A quadrotor has no redundancy, that means a lot of single point failures are possible...
One broken prop, one broken engine, broken ESC...
All said and done, its really exciting to see fly. I'd post pictures but its proprietary at the moment..
Wow, that's definitely heavy!
Good luck with the project and post some pictures whenever you can!
We ended up moving to a eight motor solution.
I think that's a very good choice!
I'm just curious here: how heavy is your aircraft?
I'm certainly not an expert but I do have a fair amount of experience with 'failures' with larger copters. :-) Fortunately things have improved greatly as I gained more experience and knowledge.
I think you'll find that the least likely component to fail will be the flight controller, regardless of which one you use. There are just so many other things that can, and will, go wrong in this class of equipment. Concentrating on those factors will give you a much better return on investment IMHO than adding the complexity and expense of redundant FCs.
Thanks for the response Darrell! I think you definitely bring up a great point, the mean time between failure on these controllers are definitely very high which makes them very reliable (thank god). I think I'm just looking for some peace of mind in knowing a beast of a UAS won't just fail and drop from the sky on me or anyone around.
I'm curious, what do you think is the biggest risk in a large quad system?
BTW, I hate to say this to you but if it flies it will more than likely crash at some point in time. So get ready for it. That's why safety protocols are so important.
Far too many solder joints and ESCs would be on my list.
I've seen PDBs from top manufactures with bullet connectors on them that snapped off. Most users avoid bullet connectors at all costs but I do have some that have worked quite well. Quality components are a requirement. Don't skimp on ESCs for example. Get components that have proven track records with those that have a lot of experience.
We've seen power modules with leads that aren't soldered on properly and break. I know people who go to the extent of re-soldering the wires on ESCs because they don't trust them.
A lot of solder points are exposed. It only takes a small clip or screw to get loose to short everything out. I now use liquid electrical tape on everything and make sure every damn screw on the thing is secure. I had an ESC overheat causing the shrink wrap to melt a bit that caused a dead short to the frame of the copter. Big bang and lots of smoke on that one. Being an Octo I managed to land it fine. I know users who now insulate their ESCs from the frame because of that.
Loose connectors on the Rx or the FC can vibrate loose. Basically it's all the wiring. Go over it with a fine tooth comb and make sure every single millimetre of it is secure and tight. That in itself will improve the reliability a great deal. Someone will chime in that these are common sense things that everyone should do. That's true but I bet you'll find a lot of flight failures come down to these factors even though people are careful.