Here's one of the referenced software frameworks (if I understand correctly) used for the ingenuity control systems: https://github.com/nasa/fprime
How NASA Designed a Helicopter That Could Fly Autonomously on Mars
51–60 of 95 posts
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#52Can someone who understands aeronautical engineering explain why they went with a helicopter over a winged aircraft?
My guess is that takeoff would be too difficult for a traditional winged aircraft and VTOL was way too complicated.
But given the thin nature of the atmosphere, a helicopter seems even more difficult to get lift than a winged aircraft.
Can someone explain or link to the science between lift and air density and it's relation to helicopters and winged aircraft? Thanks!
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#53What's the point of flying a helicopter on Mars? What scientifically relevant data do you get? Its fun and cool but why?
The article covers this.
In the future maybe they can fly with LiDAR to get more accurate surface details for the rovers to navigate with, and finding interesting features
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#54Earlier quoted context omitted.
Actually the computing power of Ingenuity surpasses one of the Perseverance rover (and probably by a lot). The rover has a radiation hardened RAD 750 CPU (based on PowerPC 750 architecture, which was introduced in 1997 to compete with Intel's Pentium II [1,2]) with 250-150nm technology process operating at 200Mhz[3]. Ingenuity's Snapdragon 801 can reach up to 2.5 GHz and is based on more energy-efficient 28nm modern…
Do you know why radiation hardening is not needed for the Ingenuity? Is there a mechanical shield? Or is it just the shorter runtime that makes the use of an off-the-shelf processor acceptable?
I had the opportunity to go down to JPL and speak with team members about this design decision. The space hardened processors are not fast enough to do real time sensor fusion and flight control, so they were forced to move to the faster snapdragon. This processor will have not flips on Mars, possibly up to every few minutes. Their solution is to hold two copies of memory and double check operations as much as possible, and if any difference is detected they simply reboot. Ingenuity will start to fall out of the sky, but it can go through a full reboot and come back online in a few hundred milliseconds to continue flying.
In the far future where robots are exploring distant planets, our best tech troubleshooting tool is to turn it off and turn it on again.
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#55Earlier quoted context omitted.
Do you know why radiation hardening is not needed for the Ingenuity? Is there a mechanical shield? Or is it just the shorter runtime that makes the use of an off-the-shelf processor acceptable?
I had the opportunity to go down to JPL and speak with team members about this design decision. The space hardened processors are not fast enough to do real time sensor fusion and flight control, so they were forced to move to the faster snapdragon. This processor will have not flips on Mars, possibly up to every few minutes. Their solution is to hold two copies of memory and double check operations as much as possib…
Do you have a source for those fast reboots? It's running Linux after all
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#56Can someone who understands aeronautical engineering explain why they went with a helicopter over a winged aircraft? My guess is that takeoff would be too difficult for a traditional winged aircraft and VTOL was way too complicated. But given the thin nature of the atmosphere, a helicopter seems even more difficult to get lift than a winged aircraft. Can someone explain or link to the science between lift and air den…
it needs to fit inside the fairing. also what do winged aircraft use to fly?
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#57Earlier quoted context omitted.
I had the opportunity to go down to JPL and speak with team members about this design decision. The space hardened processors are not fast enough to do real time sensor fusion and flight control, so they were forced to move to the faster snapdragon. This processor will have not flips on Mars, possibly up to every few minutes. Their solution is to hold two copies of memory and double check operations as much as possib…
Do you have a source for those fast reboots? It's running Linux after all
A few hundred milliseconds seems easily doable with a custom linux distro.
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#58Can someone who understands aeronautical engineering explain why they went with a helicopter over a winged aircraft? My guess is that takeoff would be too difficult for a traditional winged aircraft and VTOL was way too complicated. But given the thin nature of the atmosphere, a helicopter seems even more difficult to get lift than a winged aircraft. Can someone explain or link to the science between lift and air den…
No runways on Mars, so takeoff could be difficult. Maybe we could do that once we have well prepared surfaces.
Helicopters can also hover and are much more manoeuvrable than fixed-wing.
Lift is proportional to density.
L = Cl x .5 x rho x v^2 x S
(L is lift, Cl a non-dimensional coefficient which depends on wing shape, rho is density, v is speed and S is surface area of the wing).
For fixed wing aircraft, v is speed of aircraft. For helicopters its the speed of the blade (when its in hover. When its moving forward its a bit more complex).
Haven't done the math but the aircraft has to be going pretty fast ('v' in the equation) to generate the required lift. This also means longer runway lengths.
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#59Earlier quoted context omitted.
Do you know why radiation hardening is not needed for the Ingenuity? Is there a mechanical shield? Or is it just the shorter runtime that makes the use of an off-the-shelf processor acceptable?
I had the opportunity to go down to JPL and speak with team members about this design decision. The space hardened processors are not fast enough to do real time sensor fusion and flight control, so they were forced to move to the faster snapdragon. This processor will have not flips on Mars, possibly up to every few minutes. Their solution is to hold two copies of memory and double check operations as much as possib…
I'm a little surprised they didn't go for three separate computers and compare them for every operation, or something like that, but I'm sure they have their reasons.
Re: How NASA Designed a Helicopter That Could Fly Autonomously on Mars
#60So many interesting details in this article. Snapdragon 801-based hw running Linux, sensor fusion from three sensors whereof some bought COTS from sparkfun (who make breakout boards for sensors, basically the sensor datasheet recommended design). 3 flights planned, but potentially more which will be planned after the three first. 30 day lifetime window, due to dependecy on the rover, which needs to conserve resources…
Actually the computing power of Ingenuity surpasses one of the Perseverance rover (and probably by a lot). The rover has a radiation hardened RAD 750 CPU (based on PowerPC 750 architecture, which was introduced in 1997 to compete with Intel's Pentium II [1,2]) with 250-150nm technology process operating at 200Mhz[3]. Ingenuity's Snapdragon 801 can reach up to 2.5 GHz and is based on more energy-efficient 28nm modern…
I haven't seen much on the 'sky crane' portion. It seems that it will just use whatever fuel it has left after the landing procedure to just get as far away as possible. It seems like the perfect place to stick some experimental imagery gear: film everything you can all the way down and transmit it back to Perseverance. And there's the possibility that it would survive its crash too with all hardware intact.