It's raining robots-
That will be the headline all of us will cringe at, when the Media goes manic over the first commercial drone crashes of any significance. The same way they do anytime something new takes a stumble (or two).
The thought of my craft hitting somebody really haunts my mind. I'm sorry to be a downer, this topic is definitely a buzz-kill from the heady intoxication of being in the midst of the next great economic boom, but I can't let it go.
So the topic is failure. Despite what your high school sports coach told you, failure is not just an option, it's a guarantee. Yes- our thrust makers, power systems, flight controls, and firmware will get better quickly. However, even if we could magically achieve 100% reliability with all of our flight critical components, failure will still be there. The most random shit is always going to happen.
I'm focusing on multicopters in particular with this project, but I feel that a similar strategy would be effective with fixed wing craft as well, in fact it's used all the time.
The specific type of failure scenario I want to tackle here is a total loss of thrust and/or control. Deployable parachutes are being developed, and seem to be working well. I would like to pursue a more passive system, an aerodynamic design built into the airframe itself. Inspired by watching Marcy fly around and wingsuit pilots, I hope to achieve a passive "auto-rotation" or glide of the entire airframe. If the the craft looses thrust, the actual act of falling makes the conversion into an alternate flight mode. A slow spiraling glide to the ground, with a gear down orientation maintained. Energy absorbing landing gear, maybe even a supplemental air bag would compliment the design. The key in my opinion is making the recovery mode completely non-dependent on any system other than gravity and wind resistance. Time is so critical in a recovery scheme for these types of failures at the altitude multis usually work. No sensors, servos, or firmware required, just a thoughtful arm and frame design. The challenge will be to prevent undesired flight characteristics while in normal powered flight, in fast controlled descents we don't want to be induced into a flat spin! Can the free fall decent rate be slowed enough to usefully lower the risk of damage on the ground and airframe itself?
Step one- Get to the sewing machine and build a Bat suit for one of my quads
To be continued.