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by njoubert 1823 days ago
The article title is still misleading. The sensor fusion was the root cause of the malfunction, it was not the advanced control technique that was deployed to survive the anomaly.
2 comments

My understanding from reading an earlier explanation from JPL was that it appeared the issue wasn't so much from the missing frame itself but rather the software not being tolerant of the frame count being off.

IIRC, it seemed more like a missing test case or scenario in the software validation suite might have been the ultimate root cause.

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?
This reminds me of the adage “ Never go to sea with two chronometers; take one or three” [1] to avoid this exact conundrum

[1] https://en.m.wikipedia.org/wiki/Triple_modular_redundancy#Ch...

Incidentally, I learned the hard way why you never run two instances of Consul (or any Raft powered stack), only 1 or 3. All sorts of wacky state can occur.
You have the navigation system as a third ‘sensor’, but in this case the sensor with an abnormal spike could be disregarded