ATTI to GPS transition while in flight?

[HighlandsVideo]

I have read flight logs posted on this forum that show a Home Point(HP) getting set well after launch in mid-air

If so, I would consider this a serious flaw in the firmware!

There should be no capability to automatically set a home point after launch. What purpose would that ever serve. The OP should have the ability to reset the home point during the flight, but the craft must never do so automatically, I would think. Just asking for catastrophe.

One firmware upgrade mentioned the addition of, I think it was called dynamic home point, intended I presume to allow the controller's location to be a mobile home point, again provided the device is equipped with GPS.

 

[sar104]

If so, I would consider this a serious flaw in the firmware!

There should be no capability to automatically set a home point after launch. What purpose would that ever serve. The OP should have the ability to reset the home point during the flight, but the craft must never do so automatically, I would think. Just asking for catastrophe.

One firmware upgrade mentioned the addition of, I think it was called dynamic home point, intended I presume to allow the controller's location to be a mobile home point, again provided the device is equipped with GPS.

It's not really a flaw in the firmware. The aircraft sets the home point as soon as it has a GPS location lock. If you choose to take off before that happens then it will still set a home point as soon as it can. The alternative would be that it never set a home point if you took off before it had a position lock unless you set it manually (which you can still do anyway). That would likely cause more problems - at least with the current scheme it will likely return to approximately the correct location in most cases.

 

[HWCM]

Its

If so, I would consider this a serious flaw in the firmware!

There should be no capability to automatically set a home point after launch. What purpose would that ever serve. The OP should have the ability to reset the home point during the flight, but the craft must never do so automatically, I would think. Just asking for catastrophe.

One firmware upgrade mentioned the addition of, I think it was called dynamic home point, intended I presume to allow the controller's location to be a mobile home point, again provided the device is equipped with GPS.

It's because he took off before the home point was set. If you don't hear the lady say "Home point has been set", then it will set after you take off and the mavic has acquired enough satellites. It's not a firmware flaw, it's a pilot flaw.

 

[HWCM]

It's not really a flaw in the firmware. The aircraft sets the home point as soon as it has a GPS location lock. If you choose to take off before that happens then it will still set a home point as soon as it can. The alternative would be that it never set a home point if you took off before it had a position lock unless you set it manually (which you can still do anyway). That would likely cause more problems - at least with the current scheme it will likely return to approximately the correct location in most cases.

Exactly, it will return pretty close to where you are and you can control it back to where you are.

 

[HighlandsVideo]

at least with the current scheme it will likely return to approximately the correct location in most cases.

OK, That makes some sense, provided it sets a home point somewhere near the launch site, but I contend that if if can automatically set it, it might do so miles away like after loosing and regaining GPS, for example. I guess I would prefer it had no home point rather than the ability to set one on its own, but that's just me since I choose never to rely on the RTH.

 

[HighlandsVideo]

It's not really a flaw in the firmware

Flaw might not be the right term, but how it could have nothing to do with the firmware? It would be the code in the firmware which gives the drone the ability to autonomously set a home point after take off and rewriting said firmware would be the only way to change it.

 

[sar104]

OK, That makes some sense, provided it sets a home point somewhere near the launch site, but I contend that if if can automatically set it, it might do so miles away like after loosing and regaining GPS, for example. I guess I would prefer it had no home point rather than the ability to set one on its own, but that's just me since I choose never to rely on the RTH.

It won't reset the home point if it loses and re-acquires a GPS lock - it stays at its originally set location.

 

[sar104]

Flaw might not be the right term, but how it could have nothing to do with the firmware? It would be the code in the firmware which gives the drone the ability to autonomously set a home point after take off and rewriting said firmware would be the only way to change it.

I'm not disputing that it is firmware-defined behavior - what I meant is that it is not a flaw.

 

[gjhick]

Its

It's because he took off before the home point was set. If you don't hear the lady say "Home point has been set", then it will set after you take off and the mavic has acquired enough satellites. It's not a firmware flaw, it's a pilot flaw.

It's a pilot "decision" to fly without satellite lock - not a "flaw". With my previous Phantom, which has a manual ATTI/GPS switch, I intentionally made flights in canyons and caves in ATTI mode with no home point set. The difference with the Mavic is that it will switch between those modes without pilot input and - as per this thread - it will set a home point when it does. Not a huge issue but definitely something to be alert for.

 

[gjhick]

This is an old thread, but as I was actually in this situation today (launching in a steep canyon with no satellite reception) I wanted to report back.

So .... in a canyon (or cave), if VPS sensors are active then the Mavic will launch in OPTI mode and won’t allow more than 16 feet elevation gain above the launch point. To proceed, you will need to turn off VPS so that the Mavic is instead flying in ATTI mode. And then, as several others have already said in this thread, the Mavic will eventually set a new home point and switch to GPS mode, once it acquires enough satellites — it may be some distance from the launch point when that happens.