JJB*
Core User of DJI
Flight distance : 12260774 ft
Netherlands
Offline
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Bashy Posted at 9-30 19:14
You guys contradict each other with regards to horizontal positioning/vertical hold, which is it, please? because i am fairly sure its vertical holding else why would some drones in the past swim when they have been over water and i am fairly sure at least one of them was just hovering taking a shots of a waterfall.
Labroides "Horizontal position holding can be problematic when low over water, but not vertical height holding."
Hi,
It is common on public fora the member differs from opinion.
Myth or facts.
If i read the manual and check the Vision Used value in the log than it is clear.
GPS is used for horizontal positiong when GPS signal is good.
With a weak GPS signal the Vision is used for this horizontal positioning.
If vision is used is seen on the log, True/False value for "Vision used"
Easy to check, if GPS < 3 that True for Vision.
But what role does the Downward Vision have in positioning when GPS signal is strong?
Does it help/assist horizontal positioning when GPS is strong and False is set for Vision used in the log?
I do no see any difference in hover precison on my crafts, flying on GPS or flying only using the vision. (indoors or in dense wood waiting for the sats to come through...)
Vertical positioning (height control) is done by the info from the barometric sensor, but IR height sensor info is used as well in some situations. For example flying too low and it will fly up or lowering the descent speed when lowering craft from high height into IR range towards the ground. (from 5 m/s to 3, to 2 and to zero at 0.5 meter)
If this IR sensor has more influence on height control in other situation is the question.
Seen few logs (plus my own experience), flying low over water, where drone could not keep height control, always a case where the IR height sensor did measure yes/no height.
Conclusion : IR height height info affects the height control.
Seen few logs where keeping positioning over (streaming) water was not possible, but always with GPS < 3 and Vision is use.
Over streamimg water drone drifted from position (no RC input ofcourse).
Never saw this drifting with a Good GPS lock, so if someone love to share such a log, love to see this data!
cheers
JJB |
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