71–80 of 101 posts
This bathtub style curve for perception of NASA design by HN commenters makes me question if the perception correlates with reality.
I can't think of a polite way to say this, but as someone who professionally develops drone software, both of the software failures experienced by Ingenuity have been embarrassingly amateur at a technical level. The first failure, which delayed the initial spin test, was described as a "watchdog timeout", which for anyone not familiar with embedded development basically means the code crashed. We all write code that…
In my opinion assuming they were "testing in production" (production being mars!), or writing code that "definitely not have passed code review", or that they did not do couple of hours of flight testing on earth, is an unnecessarily unkind assessment of this project.
[1] Helicopter Models and Test Facilities: https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_A...
NASA systems appear to have the property that they are both perfectly designed when HN commenters do not understand the code and amateurishly designed when they have errors. This bathtub style curve for perception of NASA design by HN commenters makes me question if the perception correlates with reality.
I can't think of a polite way to say this, but as someone who professionally develops drone software, both of the software failures experienced by Ingenuity have been embarrassingly amateur at a technical level. The first failure, which delayed the initial spin test, was described as a "watchdog timeout", which for anyone not familiar with embedded development basically means the code crashed. We all write code that…
From my perspective, I see a project that took years of prep. Multiple papers were written. It was tested on software sim, and NASA's physical space simulator[1]. And it finally _successfully_ flew on mars, with some minor bugs. In my opinion assuming they were "testing in production" (production being mars!), or writing code that "definitely not have passed code review", or that they did not do couple of hours of fl…
I am very skeptical of the claim that this code was not tested before launch.
Earlier quoted context omitted.
> Sensor fusion that incorporates visual information is outside of the typical classical controls sphere and is likely considered part of an advanced controls segment of the devices firmware as opposed to the bog standard deterministic controls algorithm. Not so advanced as very correctly pointed out by https://news.ycombinator.com/item?id=27554949 Motor-attitude control loop cannot, and should not be "fused" with na…
Do any of these commenters have experience designing small "helicopter" "drone" avionics systems using off-the-shelf hardware, as in Ingenuity? For instance, you mention "aerospace grade" inertial sensors, yet Ingenuity apparently uses COTS components in that role^[1]. There are smart people on HN, but unless they have actual professional experience designing similar vehicles, I'm inclined to give the JPL folks the b…
The commentator is correct. And saying something is done wrong is not the same as saying someone is incompetent.
While I understand you're trying to point out hubris, you're swaying the other way and appealing to authority.
Fusing video with IMU for navigation is called VIN (visual-inertial navigation) or VIO (visual-inertial odometry) and the field has made enormous progress over the last 10-15 years. It's the same technology that the iPhone uses for all its AR features. Dropped frames are one of the easiest things to handle. Yes, the visual feature tracking depends on frames of video but even cheap phone IMUs these days are good enoug…
It means that the people who know most about closed-loop vehicle control were not involved in the design of the copter. Such fragility is a really elementary design mistake any experienced engineer would not make. Certainly the vehicle that delivered the lander would not suffer from the same mistake. My interpretion is that the copter, as an inessential system component, was seen as an opportunity for junior people t…
or are you relying on a third party article's interpretation and then extrapolating that even further?
Fusing video with IMU for navigation is called VIN (visual-inertial navigation) or VIO (visual-inertial odometry) and the field has made enormous progress over the last 10-15 years. It's the same technology that the iPhone uses for all its AR features. Dropped frames are one of the easiest things to handle. Yes, the visual feature tracking depends on frames of video but even cheap phone IMUs these days are good enoug…
iPhone was not a first.
"Agent V" (2006) — a mobile AR game preinstalled on Nokia 3230 already has such technology.[0]
Earlier quoted context omitted.
It means that the people who know most about closed-loop vehicle control were not involved in the design of the copter. Such fragility is a really elementary design mistake any experienced engineer would not make. Certainly the vehicle that delivered the lander would not suffer from the same mistake. My interpretion is that the copter, as an inessential system component, was seen as an opportunity for junior people t…
do you have ANY evidence to support this claim? or are you relying on a third party article's interpretation and then extrapolating that even further?
Earlier quoted context omitted.
Agree. It's interesting that they don't treat the optical and gyroscopic systems as two separate sensors with the possibility to disregard one if it disagrees too much. A quick restart of the visual system would have been the most optimal solution #2020-hindsight
How would you know which one is wrong in this scenario?
[1] https://en.m.wikipedia.org/wiki/Triple_modular_redundancy#Ch...
I can't think of a polite way to say this, but as someone who professionally develops drone software, both of the software failures experienced by Ingenuity have been embarrassingly amateur at a technical level. The first failure, which delayed the initial spin test, was described as a "watchdog timeout", which for anyone not familiar with embedded development basically means the code crashed. We all write code that…