4 ms·

Is anyone working on solving the noise problem with drones? Is it even really solvable in any realistic way? What would it take to have a "silent" drone?

JoeAltmaier 6y ago
Lots can be done, but at the expense of fuel efficiency.
- buzzkillington 6y ago
  Which is much less of a problem when you can charge the drones from a carrier.
adamsea 6y ago
Our drones need a blimp mode : ) :)
- jcims 6y ago
  A lighter than air mothership makes a lot of sense. You could have the delivery drones glide to the location, fire up the propellers for the controlled package dropoff, then fly back.
- asdff 6y ago
  Kids with airsoft guns will have a field day
  - dmurray 6y ago
    Blimps aren't normally brought down by a few bullet holes. The pressure inside is close to atmospheric pressure, so helium leaks out very slowly.
Wistar 6y ago
I have often wondered if larger, shrouded, multi-bladed rotors that can spin at a much lower speed can work. Perhaps uneven blade spacing — or even articulated blades with tunable lead-lag hinges to modulate blade spacing — to spread the noise over a greater frequency range. Complex problem for sure.
- outworlder 6y ago
  > tunable lead-lag hinges See, drones traded moving parts for the annoying whiny motors(but fixed in a rigid frame). If we are going to use moving parts anyway, there's helicopters.
  - Wistar 6y ago
    First-hand experience: helicopters are wildly more difficult to fly. Perhaps the lead-lag hinges can be elastomeric and one could purchase props with different fixed hinge stiffnesses for different amounts of noise dampening or frequency spread but perhaps at the cost of prop-speed change response? There'd probably have to be some compensatory mechanism in the flight- or motor-control software that'd be set for a given prop's hinge elasticity. Of course, I am just idly speculating here on whether there's any benefit at all to any of my blather.

JoeAltmaier 6y ago

Lots can be done, but at the expense of fuel efficiency.

buzzkillington 6y ago
Which is much less of a problem when you can charge the drones from a carrier.

adamsea 6y ago

Our drones need a blimp mode : ) :)

jcims 6y ago
A lighter than air mothership makes a lot of sense. You could have the delivery drones glide to the location, fire up the propellers for the controlled package dropoff, then fly back.
asdff 6y ago
Kids with airsoft guns will have a field day
- dmurray 6y ago
  Blimps aren't normally brought down by a few bullet holes. The pressure inside is close to atmospheric pressure, so helium leaks out very slowly.

Wistar 6y ago

I have often wondered if larger, shrouded, multi-bladed rotors that can spin at a much lower speed can work. Perhaps uneven blade spacing — or even articulated blades with tunable lead-lag hinges to modulate blade spacing — to spread the noise over a greater frequency range. Complex problem for sure.

outworlder 6y ago
> tunable lead-lag hinges See, drones traded moving parts for the annoying whiny motors(but fixed in a rigid frame). If we are going to use moving parts anyway, there's helicopters.
- Wistar 6y ago
  First-hand experience: helicopters are wildly more difficult to fly. Perhaps the lead-lag hinges can be elastomeric and one could purchase props with different fixed hinge stiffnesses for different amounts of noise dampening or frequency spread but perhaps at the cost of prop-speed change response? There'd probably have to be some compensatory mechanism in the flight- or motor-control software that'd be set for a given prop's hinge elasticity. Of course, I am just idly speculating here on whether there's any benefit at all to any of my blather.