Bad idia in new firmware

[skyhighdiver]

2). Further improvement on detecting bad battery readings that may cause sudden landing (due to 'invalid battery' error).

Battery readings should not even factor into the flight!
its good to send us the info, its good to have a warning, but I don't want the machine to land itself unless it has lost signal.period

 

[Migmon]

2). Further improvement on detecting bad battery readings that may cause sudden landing (due to 'invalid battery' error).

Battery readings should not even factor into the flight!
its good to send us the info, its good to have a warning, but I don't want the machine to land itself unless it has lost signal.period

i flew mine to 3% today and didnt get this... not sure when its sposed to fly home

 

[jadebox]

2). Further improvement on detecting bad battery readings that may cause sudden landing (due to 'invalid battery' error).

Battery readings should not even factor into the flight!
its good to send us the info, its good to have a warning, but I don't want the machine to land itself unless it has lost signal.period

I think you're reading that wrong. I think they are saying that the fix is intended to prevent a "sudden landing" (crash?) due to a bad battery reading, not force a "sudden landing."

-- Roger

 

[garygid]

There are two different ways to estimate the remaining battery
energy. The first is to just use the total pack voltage, but
this provides only a rough estimate.

Since one cell might be lower than the other two cells
(in an unbalanced condition), the readings of all three of
the cells is needed to make a better estimate of the usable
energy remaining in the battery pack.

When the battery's data contacts are not working, the
P2V's internal flight controller will be getting no new data,
which might be interpreted as zero remaining energy,
so the flight controller might abruptly execute a forced,
emergency landing, perhaps a poor choice for handling
this situation.

 

[LeoS]

When they program the logic of 'forced landing', it's generally because of 2 things:

1. It doesn't know where 'home' is anymore (compromised gps) and it has lost control signal (can't get commands from you), so it makes a landing than taking a chance to fly 'home'.

If you think about it, this condition usually happens when the phantom is sufficiently far enough from you (weak control signal)...
so there's a much higher chance of it flying further away from you than picking the correct direction to fly home.

2. It doesn't think it has enough power to safely maintain its altitude. Rather than risk a battery cutoff during flight which results in uncontrolled crash, it puts the phantom down in one piece for you to recover.

 

[iDrone]

When the battery's data contacts are not working, the P2V's internal flight controller will be getting no new data, which might be interpreted as zero remaining energy, so the flight controller might abruptly execute a forced, emergency landing, perhaps a poor choice for handling this situation.

As of v1.05 firmware, loss of data comm between SmartBattery & PV no longer initiates an auto-landing. Instead it throws a warning message to your iDevice and suggests you fly home ASAP. But PV still monitors the SmartBattery's output terminals and if it detects it dropping below 10.65v will initiate an auto-landing. This has been carried over to v1.08 firmware as well.

iDrone

 

[Knighthawk]

When they program the logic of 'forced landing', it's generally because of 2 things:

1. It doesn't know where 'home' is anymore (compromised gps) and it has lost control signal (can't get commands from you), so it makes a landing than taking a chance to fly 'home'.

If you think about it, this condition usually happens when the phantom is sufficiently far enough from you (weak control signal)...
so there's a much higher chance of it flying further away from you than picking the correct direction to fly home.

2. It doesn't think it has enough power to safely maintain its altitude. Rather than risk a battery cutoff during flight which results in uncontrolled crash, it puts the phantom down in one piece for you to recover.

As far as it not knowing where home is and possibly flying further away - I could understand that if GPS was completely lost, but IMHO if it sees 5 or even 4 satellites, it should pretty well still know where home is. The PV uses it's own barometric altimeter to determined height, so basically the satellites are used for direction info only. Heck, even 3 could be enough for it to know where to go.

 

[garygid]

I agree, declaring that having only 6 locked satellites is a GPS in-flight failure
seems premature to me too.

 

[skyhighdiver]

I agree, declaring that having only 6 locked satellites is a GPS in-flight failure
seems premature to me too.

agree as well better to come home 20ft off than to just land a mile away or in the middle of a lake

 

[LeoS]

If the answer is that simple, why do you suppose DJI does not implement that?

 

[garygid]

Perhaps they chose to keep the hardware and software propriatary,
so that we cannot help them find bugs, and provide improvements?
Of course, that is partially a liability issue.

They do not have enough programming or design experience
to catch these bugs?
Probably they were rushing to market to get this Christmas
buying spree, and ran out of time for sufficient QC.

Perhaps they are saving some features and improvements
for their next model?
Many times each product is crippled a bit, just to leave
room for other more-expensive products.

 

[skyhighdiver]

As of v1.05 firmware, loss of data comm between SmartBattery & PV no longer initiates an auto-landing. Instead it throws a warning message to your iDevice and suggests you fly home ASAP. But PV still monitors the SmartBattery's output terminals and if it detects it dropping below 10.65v will initiate an auto-landing. This has been carried over to v1.08 firmware as well.

this is good !!
I didn't like battery data lose and auto land idea at all
if power is low ok better auto land than a dead drop but not just because of data lose

 

[Knighthawk]

If the answer is that simple, why do you suppose DJI does not implement that?

A valid question, for sure. But, good luck getting an answer from them!

 

[jadebox]

I agree, declaring that having only 6 locked satellites is a GPS in-flight failure
seems premature to me too.

If communication with the transmitter is lost (i.e. "in fail safe mode"), then it will land if there are not enough GPS locks to return home. It's not going to land just because the number of GPS locks drops to 6.

-- Roger

 

[LeoS]

Perhaps they chose to keep the hardware and software propriatary,
so that we cannot help them find bugs, and provide improvements?
Of course, that is partially a liability issue.

Their hardware and software has always been proprietary afaik, I don't see how this relate to them setting a seemingly over-conservative gps threshold.

They do not have enough programming or design experience to catch these bugs?

If you can appreciate the intricacies of phantom's design behind its apparent simplicity, I don't think you would underestimate their capability on this front.

Probably they were rushing to market to get this Christmas
buying spree, and ran out of time for sufficient QC.

And thus, they put the wrong setting by picking 'less than 7' satellites, instead of less than... say 3? (absolute minimum to triangulate a position?)

Perhaps they are saving some features and improvements
for their next model?
Many times each product is crippled a bit, just to leave
room for other more-expensive products.

I believe this happens, although it ties in to development schedule, hardware\software revisions, etc (a bit too long to elaborate here)... but in this instance, really?

Phantom III can return home with just FIVE satellite lock! Buy it today!

 

[jimre]

The more satellites you have, the more error-checking you can do. Seems to me they chose 6 to ensure a reasonable margin of error. *Maybe* it could fly home (or in the general direction of home) with only 4-5 sats but with a greater chance of error (where error means random or uncontrolled fly-away). Sounds like a classic trade-off to me.

 

[jimre]

Again, this is only an issue if you're already in Failsafe/Return to Home mode (something bad has happened) - AND it then loses the lock on 6 GPS satellites. Not quite worst-case scenario, but close.

Perhaps the resulting behavior could be an advanced user preference:

1) If you primarily fly in open fields or neighborhoods, you'd rather have the Phantom do an immediate controlled descent in this case (what it does now).

2) Or if you're flying over water or something, then you'd rather risk the Phantom trying to fly home, with fewer satellites and a smaller margin of error, and greater likelihood of fly-away.

 

[LeoS]

One more thing to do if you've lost control of the phantom (and it's not flying home):

Run like hell toward it while flicking the ATTI switch and angling your transmitter/antenna to improve its direction :shock:

 

[iDrone]

+10 absolutely! Lol!

One thing I learned performing range tests trying different antenna configurations is to restablish the Control link ASAP (you can watch the PV's beacons if you've also lost telemetry) it should come back under control when you get close enough. If the telemetry or video dropped out, I rotate the PV 90° once I get control so one of the antennas on the side of the camera faces me, then wait for a few seconds or exit & reopen the Vision app, then crab back sideways towards the LZ.

iDrone