Very informative. Thanks.And you actually did that ?
Once the AC battery hits CRITICAL ... you CANNOT over-ride the auto-land feature ...
The only action you can do is slow the descent and / or deflect the AC from its dead vertical location ...
Page 13 of manual makes this clear ....
The matter of auto-land is based on (again as per Page 13) where only enough battery remains to allow descent from the present location.
Remember that any action you then impose will INCREASE power drain and can cause power failure BEFORE landing out ...
OK - the myth of ATTI vs GPS mode and speed .... yes you can fly faster with ATTI ....BUT that means you are drawing more power from the battery to fly faster ...
Power drain is not a linear matter as throttle increased. Why ?
a) As you fly faster - drag increases and resistance to movement - increases power required.
b) Motors have efficiency curves and most efficient power point is never at 100% ... it is much lower in the usually 70 - 80% region.
c) Power draw ratio to output increases exponentially as you increase demand. Based on increased heat production in motor, in the battery itself, friction and drag in the motors.
d) As speed increases propellers enter into high speed areas especially at tips and their efficiency and conversion of power to speed reduces. As in b) Propellers have their prime efficiency point.
ATTI mode also means you are flying totally manually and not in a nice straight line ... I've been flying models for over 50yrs and I cannot fly as straight as P-GPS mode on RTH .... therefore any tiny saving you have in mA from P-GPS will be outweighed by your not so straight path home.
In P-GPS as well as ATTI mode - you can affect flight path ... and best is to leave P-GPS so you have straight line flight ... but add a slow descent so you are losing height in a gradient to your Home Point ... this avoids the large vertical element over Home Point, saving power.
I know there are some who will argue about the above ... fair enough ... each entitled to own PoV.
Nigel
How far?? And what happens if...
- Thread starter vxooxv
- Start date
- Joined
- Jun 21, 2017
- Messages
- 117
- Reaction score
- 62
- Age
- 45
I guess you misconstrued my previous post. Yes, I agree the auto land feature can not be disabled after critical battery level is reached -- but you CAN still maneuver the AC in both vertical and horizontal axes to choose a suitable landing spot. There will be a need to push up on the left stick to maintain altitude to fight the auto descent feature.
Your exact statement of "it will auto land no matter what you do" is somewhat misleading because it gives the impression that once the auto land feature is initiated then manual control of the AC is no longer possible.
Last edited:
Sorry but I think you have it mis-construed .... here are quotes from my previous posts all saying that control can affect landing position :
Quote :
"kicks in again and cannot be cancelled .... you can only adjust the point it lands !!"
and
"The only action you can do is slow the descent and / or deflect the AC from its dead vertical location ..."
and
"Page 13 of manual .... Auto Land will kick in and you can only adjust landing point ... it cannot be cancelled"
Unquote ....
....... So where do we differ on this point ? I never said you could not affect landed out point ... I said you cannot cancel Auto-land once critical battery reached.
Nigel
- Joined
- Jun 21, 2017
- Messages
- 117
- Reaction score
- 62
- Age
- 45
I guess it just comes down to semantics --- saying "it will auto land no matter what you do" sounds a bit confusing --- as if once auto land is initiated then you have no manual control over the AC.
A totally accurate statement would be ---- "AC will slowly descend at the exact vertical location auto land is initiated unless there is operator input on the control sticks".
Seems Jiggly Wiggly is an apt moniker for you .....
Trying to wriggle out of not reading my posts fully !
Nigel
- Joined
- Jun 21, 2017
- Messages
- 117
- Reaction score
- 62
- Age
- 45
Seems Jiggly Wiggly is an apt moniker for you .....
Trying to wriggle out of not reading my posts fully ! Nigel
You seem awfully triggered --- are you what they call a "snowflake"?
Any reasonable person who reads the statement "AC will auto land no matter what you do" will construe it as misleading --- they will assume the AC is going into fully autonomous landing and no manual input is allowed.
I guess I am not a reasonable person. I read that as once the auto-land feature "kicks in" you can not cancel it.
Your re-written statement - "AC will slowly descend at the exact vertical location auto land is initiated unless there is operator input on the control sticks." is incorrect. High winds etc can blow it off course. So if we are going for being precise...
Your re-written statement - "AC will slowly descend at the exact vertical location auto land is initiated unless there is operator input on the control sticks." is incorrect. High winds etc can blow it off course. So if we are going for being precise...
You seem awfully triggered --- are you what they call a "snowflake"?
Any reasonable person who reads the statement "AC will auto land no matter what you do" will construe it as misleading --- they will assume the AC is going into fully autonomous landing and no manual input is allowed.
C'mon JW ...
You called me out and I replied by showing that I did not say as you claim ... I always had the rider that you could alter the position of landing.
No 'snowflake' about it ... you made a statement that Auto Landing could be cancelled when triggered by Critical battery ... which I showed by Page 13 of manual to be false.
If you think I'm 'triggered' - whatever that means ... then I think your mistaken ... I am just posting correction and facts as observed by my own flights and written by DJI themselves.
I will say this ... I have been accused of being less than respectful - and I say that it is never intended. I am a Brit who deals with claims on shipping / Fuel matters Miltary and Civilian every day ... makes me a tad on the blunt - say it straight .... after 40 odd years of it !
I do not mince words or cloak in niceties ... I speak plain and simple. No offense intended or implied.
If I want to be rude or be a bit 'off' - then it is plain for all to see and understand, as odd people have found out.
JW ... I am not trying to upset you ... just stating the info as needed.
Nigel
- Joined
- Jun 21, 2017
- Messages
- 117
- Reaction score
- 62
- Age
- 45
Like I said --- my main sticking point wasn't referring to your other posts in this thread, in which you did point out that manual control is still possible during the Auto Land process --- but rather with that short statement "AC will auto land no matter what you do". I interpreted that as meaning "Once Auto Land is initiated, there is nothing the operator can do to alter the landing spot". It's really as simple and innocent as that.
I happen to share your British bluntness when it comes to my work. I'm a senior engineer on large construction projects. Millions of dollars are riding on key decisions I have to make while on duty. The BS stops at the door when I clock in, and I wont tolerate it from my inferiors, either!
- Joined
- Jun 21, 2017
- Messages
- 117
- Reaction score
- 62
- Age
- 45
The problem with your retort is that ANY unforeseen circumstance can alter the landing spot during an Auto Land sequence --- such as a meteor strike, bird strike, errant flying baseball or football, etc. So it's rather impossible to come up with a single precise sentence that could explain every possible theoretical cause to alter the descent path during Auto Land.
My post is simply to make it clear to the Noobs that once Auto Land is initiated --- you are still free to manually control the bird to a safe landing spot as long as you still have a link to the controller.
C'mon JW ..... you are now nit-picking .....
The fact is the P3 will act to land in same GPS coords as when the Auto Land is initiated unless you input stick commands to alter that position ... so in fact wind and outside influences that are less than P3's capability will not alter that landing position .... the P3 will correct based on GPS / VPS ...
It does not get switched off when auto landing ...
So if nit-picking ... it would have to be a significant influence to alter the landing spot if you are not doing it by sticks ...
Second the distance / degree of modification to landing position is extremely limited as you are already in dire straits in terms of power availability .... something I found out to my own cost when my P3 went swimming.
Nigel
- Joined
- Jun 21, 2017
- Messages
- 117
- Reaction score
- 62
- Age
- 45
That's really a subjective assessment of how you interpret "extremely limited". On a perfectly calm day, I've flown my P3P close to half a mile back home after hitting critical battery at 10% and Auto Land initiated. Of course, that was during a "soiled diaper" moment that I don't care to repeat, but it does reinforce the idea that Auto Land serves a useful purpose as long as flights are over land and not sea
The BS stops at the door when I clock in, and I wont tolerate it from my inferiors, either!
Your inferiors? Boy, I bet your colleagues think you're a really great guy...
JW --- sorry but I am extreme.y skeptical about your claim to have flown a half mile after Auto-land initiated ... this was with 'critical battery' ?
Once you get into low battery levels - the fall in % left is fast as the voltage is no longer there to maintain the watts --- therefore the amps increase significantly.
For some months in early part of this year - I conducted extensive range testing with my P3 .... as many here know. Testing of FW's and APP's to determine best ... as well as antenna and booster systems. A few times I pushed too far and critical battery kicked in ... I soon found out the limitations. The .last one in fact had me scrambling to get into one of my boats to go rescue it from the river ... sadly the P3 is now dead after its swim .... waiting for me to decide what to do with it. Most likely I will strip out the DJI gear and hack it to a full aerobatics FPV machine ....
Nigel
Once you get into low battery levels - the fall in % left is fast as the voltage is no longer there to maintain the watts --- therefore the amps increase significantly.
For some months in early part of this year - I conducted extensive range testing with my P3 .... as many here know. Testing of FW's and APP's to determine best ... as well as antenna and booster systems. A few times I pushed too far and critical battery kicked in ... I soon found out the limitations. The .last one in fact had me scrambling to get into one of my boats to go rescue it from the river ... sadly the P3 is now dead after its swim .... waiting for me to decide what to do with it. Most likely I will strip out the DJI gear and hack it to a full aerobatics FPV machine ....
Nigel
YOUR range totally 100% depends on the environment you are flying in. Both physical and electrical environments.
Things like tress, buildings and other structures will eat into your max range.
Electrical interference such as other RF signals (cell towers, microwave repeater dishes and other WiFi signals) will eat into your max range.
Out in the country with 50mi to the nearest WiFi router, with no trees, you will get max range. In a city with lots of buildings and a crapton of RF such as radio, two-way, cell and WiFi, very limited range.
Things like tress, buildings and other structures will eat into your max range.
Electrical interference such as other RF signals (cell towers, microwave repeater dishes and other WiFi signals) will eat into your max range.
Out in the country with 50mi to the nearest WiFi router, with no trees, you will get max range. In a city with lots of buildings and a crapton of RF such as radio, two-way, cell and WiFi, very limited range.
My understanding is that the battery life decide when the RTH function kick in to make sure there is enough life left to get you home. If you say you're bat was at 60% when returning home that tells me you where a long distance from the home point
- Joined
- Aug 15, 2016
- Messages
- 3,591
- Reaction score
- 1,540
- Age
- 43
On my own experience when the 10% critical automatic landing kicked in this is what happened...
* I can control the bird left, right, forward, backwards, yaw left, yaw right
* I can slow down the descent (this was from 80 meters, any higher then maybe it would over ride my slowing down as it needs to land before battery hits 0%)
* In no way could I cancel the auto land after 10% critical battery.
Hope that helps [emoji4][emoji4]
* I can control the bird left, right, forward, backwards, yaw left, yaw right
* I can slow down the descent (this was from 80 meters, any higher then maybe it would over ride my slowing down as it needs to land before battery hits 0%)
* In no way could I cancel the auto land after 10% critical battery.
Hope that helps [emoji4][emoji4]
- Joined
- Mar 8, 2016
- Messages
- 624
- Reaction score
- 258
- Age
- 67
OP: I don't go for distance, but I still use the parabolic antenna extenders to maintain a good signal in areas of strong interference.
Yes, if you lose signal the RTH kicks in, but keeping a strong signal means you can keep on the job without it stopping and turning back home.
Scenario: If you lose signal and it kicks into RTH before you're done, and you don't regain signal until it's part way back, you may not have enough battery to go return to finish the job. So you *sigh* and let it come home so you can swap out to a full battery then go back out. Using the parabolic antenna extenders helps ensure that you can stay out there the first time without interruption.
Speck
Yes, if you lose signal the RTH kicks in, but keeping a strong signal means you can keep on the job without it stopping and turning back home.
Scenario: If you lose signal and it kicks into RTH before you're done, and you don't regain signal until it's part way back, you may not have enough battery to go return to finish the job. So you *sigh* and let it come home so you can swap out to a full battery then go back out. Using the parabolic antenna extenders helps ensure that you can stay out there the first time without interruption.
Speck
Thank you for that ... I have been trying to get this through to some others who kept insisting Auto-Land can be cancelled ....
Nigel
- Joined
- Oct 4, 2015
- Messages
- 154
- Reaction score
- 22
Before I started flying on longer distances and higher altitudes I made a simple test.
I just went to a safe area and turned off the remote while I was flying. That's the same thing as you would lose a signal when you're far away.
I wanted to know what would happen when flying well above the RTH altitude because I was afraid that it would descent to the RTH altitude and then return home. It wouldn't be a good idea because there could be a mountain in between. And it didn't.
Similar threads
