Obstacle avoidance - Do I really need it to turn ON? Especially when I am running in high altitude and there is no chance of colliding with any substance. I turn off when I fly it indoors. is there any impact of it on return to home or any other aspect of flying? Turning it off also increase the front speed I think?

you are correct you don't need it on for every flight..

and you are also correct about the speed..

the spark has 4 speeds... or speed limits..

tripod

collision sensors on

collisions sensors off

sport

DJI likes to tout its software and how intelligent its flight systems are yet their apps are quite dumb and offer little in automation or smarts..

for example.. if I have a RTH altitude set.. IE a harddeck where above that altitude there should be no obsticals  .. collision avoidance should turn off once above that RTH altitude and re-engage if I manually fly below it... simple right?

Only in areas near obstacles to avoid - I almost always switch it off

Does this effect return to home functionality in any way? I mean if I turn off the collision detection, will it return to home without any problem?

Ehsancgfx Posted at 2018-10-19 23:41
Does this effect return to home functionality in any way? I mean if I turn off the collision detection, will it return to home without any problem?

That's a good point. If you're are doing automatic RTH then I'd leave it on. Might save your drone from trees, branches, buildings while it's coming home on autopilot.

Hi Ehsancgfx, thank you for reaching DJI Forum.  We do appreciate bringing this query to us. In general, obstacle avoidance should be enabled especially when you fly your aircraft in urban areas. If you are flying at a high altitude as you mentioned, then there's no need to have it ON since there is no chance of colliding. Have a safe flight always.

Ehsancgfx Posted at 2018-10-19 23:41
Does this effect return to home functionality in any way? I mean if I turn off the collision detection, will it return to home without any problem?

Just ensure your RTH altitude is set higher than any obstacles in the area before take off.

Ehsancgfx Posted at 2018-10-19 23:41
Does this effect return to home functionality in any way? I mean if I turn off the collision detection, will it return to home without any problem?

Have a look in the 'Advanced Settings' in the 'Visual Navigation Settings' menu in DJI Go 4. There you should see 'RTH Obstacle Check', have a read of the note there. It states that, if enabled, RTH Obstacle Check  will function in RTH even if Obstacle Avoidance is disabled.

The real question is, does it conserve battery and result in longer flight time when it is turned off? But the test would have to be in a controlled environment.

H. Arif - 6IX Posted at 2018-10-20 15:33
The real question is, does it conserve battery and result in longer flight time when it is turned off? But the test would have to be in a controlled environment.

several people have commented that anything they turn off reduces batt drain

not starting video recording until you need it, turning off sensors.. obviously taking off prop guards .. anything that saves current will increase flight time.... although I suspect very modestly ..

as one thread says.. with the drone on the ground wit motors off it uses 1 minute of flight time for every 5 minutes on the ground.. so I doubt turning off collision avoidance buys even 15 seconds of flight time due to current draw..

where having collision avoidance off buys you flight DISTANCE.. not necessarily TIME because of the faster flight speed.

just because you can fly longer doesn't mean you can fly further..

in real aircraft we have multiple performance speeds we have to know..

there is a best endurance speed... to maximize flight TIME, there is best range speed to max RANGE
additionally during takeoff there are different speeds that get us more height for distance traveled (steepest climb) as well as most efficient distance during climb for fuel burned..

any who.. if you go trucking around at collision avoidance speeds.. you will not fly as far compared to flying at around 21kts .. which I believe is the RTH speed

DJI also quotes a speed for the 16 minute flight time figure I don't recall it at the moment..
I got this from another thread

DJI's claimed 16 minute flight time is under perfect conditions that nobody flies with:  "no wind at a consistent 12.4 mph (20 kph)".


that speed is pretty close to p-mode collision off... but I get more flight distance.. 15000ft + flying more sport mode speed.. which also turns off some sensors and gimble processing .. but its the speed mostly that contributes to the greater range efficiecy ... its the same for real helicopters .. hover is very inefficient .. forward flight increases lift ...  

that is why most people that want more time on station at a point far away.. will fly out in sport mode.. switch to p-mode, film, then come home in sport or RTH speeds...

I did see a video where a guy went out to something like .9KM and hovered until 50% and flew back once at RTH and another hand flying in sport and sport had far more battery remaining than the RTH...

I would suspect that to be even more true if you flew out with a tailwind and were battling a headwind on the way back .. I would go sport to make it back..

DeuceDriv3r Posted at 2018-10-21 05:17
several people have commented that anything they turn off reduces batt drain

not starting video recording until you need it, turning off sensors.. obviously taking off prop guards .. anything that saves current will increase flight time.... although I suspect very modestly ..

I agree, Sport is quicker and more efficient than RTH, RTH also requires an increase in satellite connection to locate he exact RTH spot, Which in theory, would discharge the battery at a faster rate. thanks