Hey just curious if someone can answer this one for me.  I have a P4 and am very happy with it.  I learnt the hard way that the front obstacle avoidance needs good daylight to work as I flew mine into a fence as dusk was settling.  Broke a prop and that was all, not even a scratch on it as it fell from about half a metre onto grass, but it's the underneath sensors that I'm questioning.  If I fly my drone downwards and there is an obstacle in the way, like a massive house roof, it doesn't try to avoid it and given the chance will hit it.  Also if I fly it downwards and put my hand up it'll just hit that, doesn't try to avoid in any way.

Am I missing something here?

The P4 only has obstacle avoidance in the forward direction, the sensors on the bottom are to aid positioning, and do not provide obstacle avoidance at all.

I was also wondering that, now we know. Maybe the next phantom 5 will have downwards obstacle avoidance.

Not sure how you would land it with obstacle avoidance below?  

I did find it a bit disappointing that it is possible to fly it forward into a gentle slope, the ground doesn't seem to count as an obstacle, it could easily prevent that with it's sonar and enforce zero horizontal speed at less than 1 meter altitude and for a landing.

fans689722dd Posted at 2016-12-18 15:17
I was also wondering that, now we know. Maybe the next phantom 5 will have downwards obstacle avoidance.

I don't think you will ever see downward OA , this would cause more problems than it could ever solve.

Nigel_ Posted at 2016-12-18 16:32
Not sure how you would land it with obstacle avoidance below?  

I did find it a bit disappointing that it is possible to fly it forward into a gentle slope, the ground doesn't seem to count as an obstacle, it could easily prevent that with it's sonar and enforce zero horizontal speed at less than 1 meter altitude and for a landing.

It should rise if it meets a slope during tracking (altitude <10m):-

Aardvark Posted at 2016-12-18 22:28
It should rise if it meets a slope during tracking (altitude

I think that is only when using active track?

If I have an almost flat field and just fly it normally across the field at a height of 1m without realising that the field is 2m higher at the other end then it will crash even with obstacle avoidance turned on...

Nigel_ Posted at 2016-12-19 07:26
I think that is only when using active track?

If I have an almost flat field and just fly it normally across the field at a height of 1m without realising that the field is 2m higher at the other end then it will crash even with obstacle avoidance turned on...

I have a P3 advanced If I am flying at 2feet high and walk up a slope or down the P3 keeps the same altitude .This is in p mode and about 20 feet away and walking pace.Not game to try higher or faster

Geebax Posted at 2016-12-18 16:02
The P4 only has obstacle avoidance in the forward direction, the sensors on the bottom are to aid positioning, and do not provide obstacle avoidance at all.

That explains it, cheers.

Oh and thanks for the other input too! ...