Mars helicopter employs advanced control techniques to survive in-flight anomaly
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Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#2After five successful flights, the Mars Helicopter had a minor incident during its sixth voyage that was fixed using advanced control systems.
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#3Time to set up a GPS constellation on Mars? Somehow forgot that this navigation aid -- that we take for granted on Earth -- is missing on this other planet.
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#4It’s cool to see how they compensated for the IMU inaccuracy. I bought an IMU off of Amazon once and tried to use it to measure the position of a steering wheel. This worked for one rotation, but as it mentions, it’s incredibly hard to compensate for the error margin — as you integrate more measurements, the error builds up irreconcilably to the point where it’s a useless instrument.
I am sure the one on the Mars helicopter had more precision though :)
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#5I see no mention of "advanced control techniques"? Sounds like there is just a limit on roll/pitch angles and a limit on distance applied. Saying "advanced control techniques [for multirotors]" sets an expectation for something along the lines of Tedrake's Underactuated Control approaches: http://underactuated.mit.edu/
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#6Time to set up a GPS constellation on Mars? Somehow forgot that this navigation aid -- that we take for granted on Earth -- is missing on this other planet.
Pretty sure SpaceX's first deliveries to Mars (orbit) will include just that. I think they could probably use Starlink satellites without much modification (most important one I can think of would be more panels to cope with the reduced solar irradiance)?
The GPS constellation has 32 satellites. A GPS satellite weighs ~2000kg. Starship should get 100-150 tons to Mars - the math checks out! (Disclosure: I got all my rocket science from sending Kerbals to their doom.)
So, MPS for Mars, LPS for Luna? Just imagine the amount and quality of rover footage we could get if each of them had (constant!) 1Gbps uplink to Earth...
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#7Time to set up a GPS constellation on Mars? Somehow forgot that this navigation aid -- that we take for granted on Earth -- is missing on this other planet.
It might be enough for the rover to just drop a few radio beacons at various distances.
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#8I see no mention of "advanced control techniques"? Sounds like there is just a limit on roll/pitch angles and a limit on distance applied. Saying "advanced control techniques [for multirotors]" sets an expectation for something along the lines of Tedrake's Underactuated Control approaches: http://underactuated.mit.edu/
Sensor fusion is part of the control system. 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. You need not gatekeep here, this is a real term.
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#9I see no mention of "advanced control techniques"? Sounds like there is just a limit on roll/pitch angles and a limit on distance applied. Saying "advanced control techniques [for multirotors]" sets an expectation for something along the lines of Tedrake's Underactuated Control approaches: http://underactuated.mit.edu/
I wish they had gone into more detail. Unfortunately, my experience is that, yes, such limiters do count as "advanced."
First time I got my hands on a working mounted arm, I was cautioned again and again the need to run any new program in low-speed mode first. Because the arm had no limiting logic and would cheerfully power-bomb its own base with all the force and torque its motors could muster if I told it to.
Preventing that is still considered an "advanced technique."
Re: Mars helicopter employs advanced control techniques to survive in-flight anomaly
#10Time to set up a GPS constellation on Mars? Somehow forgot that this navigation aid -- that we take for granted on Earth -- is missing on this other planet.
Yes, but wouldn't help with this particular problem. This was a roll/pitch issue, not fundamentally a position issue.