Hi, I aways fly at same location, even with low light and visual positioning disabled. But this time several time I got VPS misreading, one of times it tried land automatically even 20 meters altitude..

I already calibrated visual sensors in notebook twice. In status it say that it's normal..

This + upward sensor on even with obstacle avoidance off caused crash when I was taking off from 10th floor balcony (when I was indoor going to outdoor), it fallen from 10th floor in the ground..
I already did about 250 flights with exactly same conditions, taking off from balcony and flying wirg same light level at night in same location and never had any problem.. Then it starter happening.. Somebody know solution?

Here is video showing it:

Quite amazed you use to get OA sensors working when flying in the dark - I would expect low ambient light to automatically turn them off.

Hiya,

Question....was Landing Protection ON?  if yes, than when VPS is measuring low altitude and with 100% stick down the software thinks you want to initiate a landing.
This is seen in the beginning of the video. Only 100% up does cancel the autolanding (as you did).

Don`t know why VPS height did indicate, flying close to the building mayby ??

Cannot comment on th fall from the 10th floor to the ground, if you like upload that flightlog on here.

cheers
JJB

VPS doesnt work at night.  The manual states that.  No amount of calibrating will help - the cameras are visual light not night vision.  The solution is disable them and not rely on them in low light.

Check to make sure your sensors are clean, shouldn't you be using the bottom LED lighting if you insist on flying at night, might not be amazing but should at least help your sensors to see something other than pitch black darkness. All the other vision sensors probably wont be useful at all at night so you should just turn them off.

JJB* Posted at 8-12 00:14
Hiya,

Question....was Landing Protection ON?  if yes, than when VPS is measuring low altitude and with 100% stick down the software thinks you want to initiate a landing.

He's flying at night JJB - close your eyes and what do you see - same principle with OA!

A J Posted at 8-12 05:13
He's flying at night JJB - close your eyes and what do you see - same principle with OA!

i know he was flying at night. Watch his VPS height indicates 0.2 or 03, 100% down stick.
For the SW its all the same, day or night for this sw action ; user initiated a forcelanding if landing protection is ON. Uh, yes it was ON that`s why you hear "landing"....
see# 8 as well

gnirtS Posted at 8-12 02:30
VPS doesnt work at night.  The manual states that.  No amount of calibrating will help - the cameras are visual light not night vision.  The solution is disable them and not rely on them in low light.

VPS visual sense does not work at night, true.
AFAIK VPS height sensor (different sensor than the visual one, at least on a MA) does work all the time.
IMO the ultrasonic sensors are the VPS height indication, works day and night.The monocular sensors ae for the VPS position, and doesn`t work with low light conditions and many more (see manual)

And yes, i agree on with you ; disabling landing protection brings more good than bad for flying a DJI drone.

JJB* Posted at 8-12 05:53
i know he was flying at night. Watch his VPS height indicates 0.2 or 03, 100% down stick.
For the SW its all the same, day or night for this sw action ; user initiated a forcelanding if landing protection is ON. Uh, yes it was ON that`s why you hear "landing"....
see# 8 as well

Landing protection utilises the VPS to gauge even ground and the transparency of the landing area in order to protect the drone from crash landing on uneven surfaces or water - this too will therefore be completely ineffective in low light conditions as the VPS will not be able to detect the surface. The drone will land when a critical error occurs and use the barometer to gauge approximate altitude - all sensors are ineffective in the dark which is my point. BTW - there are no ultrasonic sensors on the Mavic Air - it uses an IR sensor instead which is also heavily dependant on light.

A J Posted at 8-12 06:21
Landing protection utilises the VPS to gauge even ground and the transparency of the landing area in order to protect the drone from crash landing on uneven surfaces or water - this too will therefore be completely ineffective in low light conditions as the VPS will not be able to detect the surface. The drone will land when a critical error occurs and use the barometer to gauge approximate altitude - all sensors are ineffective in the dark which is my point. BTW - there are no ultrasonic sensors on the Mavic Air - it uses an IR sensor instead which is also heavily dependant on light.

Is this correct ? I was under the impression that the IR LED and the IR sensors are one unit, so darkness wouldn't be a massive factor with the IR sensor, as it is emitting the IR wave itself and sensing it's feedback. Isn't the opposite true? Massive amounts of sunlight/IR light would drown out the sensor and cause massive issues.

JJB* Posted at 8-12 05:53
i know he was flying at night. Watch his VPS height indicates 0.2 or 03, 100% down stick.
For the SW its all the same, day or night for this sw action ; user initiated a forcelanding if landing protection is ON. Uh, yes it was ON that`s why you hear "landing"....
see# 8 as well

This is not how I read it if Landing protection IS NOT on pulling down 100% on throttle will bring craft below .05

Ben Mason Posted at 8-12 06:35
Is this correct ? I was under the impression that the IR LED and the IR sensors are one unit, so darkness wouldn't be a massive factor with the IR sensor, as it is emitting the IR wave itself and sensing it's feedback. Isn't the opposite true? Massive amounts of sunlight/IR light would drown out the sensor and cause massive issues.

The IR sensor needs to detect and relay information to the flight controller working with the two downward facing cameras that make up the overall vision positioning system. That is why VPS will not work effectively in low light conditions which, therefore, impacts the stability of landing protection, precision landing and, additionally, all obstacle avoidance cameras/sensors will not work effectively too in low light conditions - it even stipulates that in the DJI manual with every drone they have manufactured.

IR transmitters also have very restricted range and the IR transmission can be absorbed very easily by certain material and highly reflective surfaces which is why the VPS has proximity cameras in addition to IR and also explains why the Mavic 2 series now uses an AUX light that turns on automatically when landing in low light and also explains the 7m, limited range and function of the IR side sensors on the Phantom 4 Pro models.

hallmark007 Posted at 8-12 06:44
This is not how I read it if Landing protection IS NOT on pulling down 100% on throttle will bring craft below .05

tested this on my Mavic Air.

If Landing protection in ON :  hover at low altitude, apply 100% down stick and MA will do a automatic landing (in the log as 'ForceLanding' ), all sticks to zero and stll autolanding.
To stop this landing pull 100% up and autolanding will stop.

If Landing protection in OFF, hover at low altitude and you have to bring your drone manual down, adjusting the down speed with the stick.

IMO the 'problem' with this Landing protection ON is that is uses the VPS height data, if VPS height is measuring low height (fog, dirt, ect) and user apply 100% stick down the SW will initiate a 'force landing';
You can check it out by yourself.

cheers
JJB

A J Posted at 8-12 06:21
Landing protection utilises the VPS to gauge even ground and the transparency of the landing area in order to protect the drone from crash landing on uneven surfaces or water - this too will therefore be completely ineffective in low light conditions as the VPS will not be able to detect the surface. The drone will land when a critical error occurs and use the barometer to gauge approximate altitude - all sensors are ineffective in the dark which is my point. BTW - there are no ultrasonic sensors on the Mavic Air - it uses an IR sensor instead which is also heavily dependant on light.

right, MA has an IR sensor.
Will test my IR sensor out at night, see if VPS height is measuring height or not.

JJB* Posted at 8-12 07:06
right, MA has an IR sensor.
Will test my IR sensor out at night, see if VPS height is measuring height or not.

Be careful - always best to switch off at night or you may be joining the OP!

JJB* Posted at 8-12 07:04
tested this on my Mavic Air.

If Landing protection in ON :  hover at low altitude, apply 100% down stick and MA will do a automatic landing (in the log as 'ForceLanding' ), all sticks to zero and stll autolanding.

I’m only going by what the manual tells me, I think having landing protection on is good for many reasons.

A J Posted at 8-12 06:48
The IR sensor needs to detect and relay information to the flight controller working with the two downward facing cameras that make up the overall vision positioning system. That is why VPS will not work effectively in low light conditions which, therefore, impacts the stability of landing protection, precision landing and, additionally, all obstacle avoidance cameras/sensors will not work effectively too in low light conditions - it even stipulates that in the DJI manual with every drone they have manufactured.

IR transmitters also have very restricted range and the IR transmission can be absorbed very easily by certain material and highly reflective surfaces which is why the VPS has proximity cameras in addition to IR and also explains why the Mavic 2 series now uses an AUX light that turns on automatically when landing in low light and also explains the 7m, limited range and function of the IR side sensors on the Phantom 4 Pro models.

Just read the M2Z manual.

2 type of sensors at the bottom ;  downward vision sensor and downward infrared sensor.

In the manual a !  Visual system are disabled during landing. (imo = the visual sensing for obstacles)
But Landing protection remains ON during low batt RTH and failsafe RTH (imo = the other sensor for measuring height)

If Landing protection is ON and you manually bring the craft to a low hover, and do 100% stick down, it does work as well as ; a controlled landing done by the SW.

cheers
JJB

hallmark007 Posted at 8-12 07:17
I’m only going by what the manual tells me, I think having landing protection on is good for many reasons.
[view_image]

yes, this is during a Smart RTH. i am talking when flying manual.

as is said, give it a try with your drones.

A J Posted at 8-12 06:48
The IR sensor needs to detect and relay information to the flight controller working with the two downward facing cameras that make up the overall vision positioning system. That is why VPS will not work effectively in low light conditions which, therefore, impacts the stability of landing protection, precision landing and, additionally, all obstacle avoidance cameras/sensors will not work effectively too in low light conditions - it even stipulates that in the DJI manual with every drone they have manufactured.

IR transmitters also have very restricted range and the IR transmission can be absorbed very easily by certain material and highly reflective surfaces which is why the VPS has proximity cameras in addition to IR and also explains why the Mavic 2 series now uses an AUX light that turns on automatically when landing in low light and also explains the 7m, limited range and function of the IR side sensors on the Phantom 4 Pro models.

I never mentioned Vision sensors, my comment was in regards to the Raw data from the IR sensors, which is not effected by darkness.

A J Posted at 8-12 07:12
Be careful - always best to switch off at night or you may be joining the OP!

I was and am always careful flying and flying drones!

JJB* Posted at 8-12 07:19
Just read the M2Z manual.

2 type of sensors at the bottom ;  downward vision sensor and downward infrared sensor.

Of course it will work but it is not detecting obstacles - if the drone can not detect the ground it will hover in landing protection then you will need to make a judgement on whether to bring the drone down to the ground manually by holding down the throttle stick for couple of seconds. With sufficient light the drone will be able to land immediately without a pop up slider whilst being able to detect the ground with the aid of the internal AUX light.

Ben Mason Posted at 8-12 07:36
I never mentioned Vision sensors, my comment was in regards to the Raw data from the IR sensors, which is not effected by darkness.

Yes, but my point is that the VPS of the drone is not just an IR sensor so the limitations of the overall vision system also need to be taken into consideration. I do not believe that the IR sensors work idependantly to enable sensing in the dark. Otherwise DJI would surely advise that the IR sensors will compensate for the limitations of the other sensors and flying in low light with obstacle detetion will be fine. That does not appear to be the case.

Ben Mason Posted at 8-12 07:36
I never mentioned Vision sensors, my comment was in regards to the Raw data from the IR sensors, which is not effected by darkness.

Guess you are right.

Did not have to test fly this night, i already have some night data.Pitch dark night and VPS indicates steady, almost the range as in the manual.
see #25
cheers
JJB

JJB* Posted at 8-12 07:26
yes, this is during a Smart RTH. i am talking when flying manual.

as is said, give it a try with your drones.

It doesn’t make sense, if I’m 0.3 meter above the ground and I press 100% down I’m initiating craft to land, I haven’t seen anything regarding this in fog, but the same if I’m above a roof at 0.3 m and I push throttle down 100% that’s what I as the controller wants it to do , that’s a bit like saying if you want your craft to go down you can’t , that can’t be right.
If you command up craft should go up if you command left expect it to go left so it seems right that if I command down it should go down, I’m not certain this is causing forced landing, I have just tried with Mavic Air going forward over hedge 100% down on left stick from approx .5 metre, it beeps and jumps up because of OA.
I try approx 0.3m off the ground left stick 100% down craft lands this is correct and what I expect .

see my video at night
front sensor is watching the dark at ground level (thus warning), back sensor is watching the house with some lights.
After take both sensors are in the darkness.

JJB* Posted at 8-12 07:51
see my video at night
https://vimeo.com/353389872

Is that with the Spark which uses an IR sensor only for forward facing obstacle avoidance. Does that work in the dark?

A J Posted at 8-12 07:58
Is that with the Spark which uses an IR sensor only for forward facing obstacle avoidance. Does that work in the dark?

I guess not looking at the spark manual which also advises when "lighting conditions are sufficient" and that only uses IR to the front...

hallmark007 Posted at 8-12 07:50
It doesn’t make sense, if I’m 0.3 meter above the ground and I press 100% down I’m initiating craft to land, I haven’t seen anything regarding this in fog, but the same if I’m above a roof at 0.3 m and I push throttle down 100% that’s what I as the controller wants it to do , that’s a bit like saying if you want your craft to go down you can’t , that can’t be right.
If you command up craft should go up if you command left expect it to go left so it seems right that if I command down it should go down, I’m not certain this is causing forced landing, I have just tried with Mavic Air going forward over hedge 100% down on left stick from approx .5 metre, it beeps and jumps up because of OA.
I try approx 0.3m off the ground left stick 100% down craft lands this is correct and what I expect .

Ok, it does make sense i think...

If you hover manually above the ground and you want to land (with Landing protection ON) you only have to push 100% down for a moment ; SW will take over and land you craft. Release all sticks and craft still land. Agree?

With Landing Protection OFF you have to bring her down youself, controlling the down speed with the stick. If 100% stick all the time it will be a hard landing.

I have see some logs where the craft flys high altitude and VPS height (error height) is indicating 0.3 meter, when the user than applys 100% stick down the SW acts and make the craft go into a landing.

In this thread its happening also, VPS height indicates and user gives 100% down > landing mode.
But the OP pulled up 100% so the landing mode was killed.

see this thread : https://forum.dji.com/forum.php?mod=viewthread&tid=195519   flying at 119 meters and a long-landing-time....

cheers
JJB

A J Posted at 8-12 07:58
Is that with the Spark which uses an IR sensor only for forward facing obstacle avoidance. Does that work in the dark?

Nope, its my MA  (Spark does not have APAS)

So i do believe that sensing obstacles is hardly or not possible low light conditions, but the IR sensor does work at night.

This IR sensor is for the VPS height measuring and thus indicating. and ofcourse if the IR singnal is absorbed into material than the signal back is getting weaker.

cheers
JJB

JJB* Posted at 8-12 08:09
Nope, its my MA  (Spark does not have APAS)

So i do believe that sensing obstacles is hardly or not possible low light conditions, but the IR sensor does work at night.

I do not believe the IR sensor works at night or in low light. My M2P was hovering indoors in a poorly lit room with the AUX light off and switched to ATTI mode as the IR did not detect the ground - the drone drifted into the wall and wrote off 4 blades - thankfully no harm to the actual drone. If the IR worked independently to sense the ground through the dark to assess the altitude and stabilise the hover that would not have happened. Why do none of the manuals ever written by DJI advise that the IR sensors work in the dark yet they all state the need for "sufficient lighting conditions"?

A J Posted at 8-12 08:17
I do not believe the IR sensor works at night or in low light. My M2P was hovering indoors in a poorly lit room with the AUX light off and switched to ATTI mode as the IR did not detect the ground - the drone drifted into the wall and wrote off 4 blades - thankfully no harm to the actual drone. If the IR worked independently to sense the ground through the dark to assess the altitude and stabilise the hover that would not have happened. Why do none of the manuals ever written by DJI advise that the IR sensors work in the dark yet they all state the need for "sufficient lighting conditions"?

oke, guess my MA is a special one....   in a pitch dark night it is measuring the correct height, as seen in de video.

But indoor both systems should give correct info for OPTI mode, when there is no GPS reception.
Indoors with too low light the visual sensors doesn`t work, so ATTI ofcourse.

Good question about the DJI manual, i see more 'mistakes'in the DJI manuals.

cheers
JJB

JJB* Posted at 8-12 08:27
oke, guess my MA is a special one....   in a pitch dark night it is measuring the correct height, as seen in de video.

But indoor both systems should give correct info for OPTI mode, when there is no GPS reception.

I don't think the multi billion dollar company that made the drones make that many mistakes in their instructions which has helped me in not crashing a single DJI drone outdoors in nearly 2,000 miles of flight. How about you take off with your Spark in a pitch black room and fly it towards a wall... The forward facing IR sensor will stop it crashing right?

BTW - the barometer will measure altitude without a GPS connection. That is why the drone doesn't crash into the ground when GPS is lost... In your video ALL sensors are recorded as being inoperable due to weak ambient light upon take off and you have a GPS lock - you will also notice that the 3m reading simply disappeared and did not increase as you flew away - that shows no ongoing detection or an inaccurate detection. Looking at the yaw in the radar it is also evident that you took off with the rear sensors (showing the 3m detection) facing the direction of the light coming through the curtains in the house... What are you trying to prove?

A J Posted at 8-12 08:17
I do not believe the IR sensor works at night or in low light. My M2P was hovering indoors in a poorly lit room with the AUX light off and switched to ATTI mode as the IR did not detect the ground - the drone drifted into the wall and wrote off 4 blades - thankfully no harm to the actual drone. If the IR worked independently to sense the ground through the dark to assess the altitude and stabilise the hover that would not have happened. Why do none of the manuals ever written by DJI advise that the IR sensors work in the dark yet they all state the need for "sufficient lighting conditions"?

VPs is pretty good in dark with M2, had it out the other night and it preformed pretty well and accurate readings, auxiliary lights come on at 5 m I noticed when these turn on there is some slight movement particularly as they turn on, but certainly up to 30/35 ft it’s pretty good .

hallmark007 Posted at 8-12 08:50
VPs is pretty good in dark with M2, had it out the other night and it preformed pretty well and accurate readings, auxiliary lights come on at 5 m I noticed when these turn on there is some slight movement particularly as they turn on, but certainly up to 30/35 ft it’s pretty good .

I found the VPS on my M2P to be the best in low light accuracy for sure. Why would the AUX lights turn on automatically if the IR sensor can still detect the ground in the dark without them? Or am I right in thinking that the readings from both the downward vision cameras and the IR sensor need to be operable for the whole VPS to work efficiently?

A J Posted at 8-12 09:00
I found the VPS on my M2P to be the best in low light accuracy for sure. Why would the AUX lights turn on automatically if the IR sensor can still detect the ground in the dark without them? Or am I right in thinking that the readings from both the downward vision cameras and the IR sensor need to be operable for the whole VPS to work efficiently?

You can set auxiliary lights to come on automatically in low light when craft is within 5 metres from the ground .

hallmark007 Posted at 8-12 11:22
You can set auxiliary lights to come on automatically in low light when craft is within 5 metres from the ground .

Yeah they are good to have and also helps with VLOS when flying as can be left on permanently and seen quite far away. As for the sensors, they should never be replied upon 100% as we all know so I'll just continue to follow the advice in the manuals as that works for me.

A J Posted at 8-12 08:35
I don't think the multi billion dollar company that made the drones make that many mistakes in their instructions which has helped me in not crashing a single DJI drone outdoors in nearly 2,000 miles of flight. How about you take off with your Spark in a pitch black room and fly it towards a wall... The forward facing IR sensor will stop it crashing right?

BTW - the barometer will measure altitude without a GPS connection. That is why the drone doesn't crash into the ground when GPS is lost... In your video ALL sensors are recorded as being inoperable due to weak ambient light upon take off and you have a GPS lock - you will also notice that the 3m reading simply disappeared and did not increase as you flew away - that shows no ongoing detection or an inaccurate detection. Looking at the yaw in the radar it is also evident that you took off with the rear sensors (showing the 3m detection) facing the direction of the light coming through the curtains in the house... What are you trying to prove?

uh ?? have i been in any way dis-respectful to you?

As i said ; the VPS visual sensors does not work well in a pitch dark flight, so yes ofcourse the 3M indication dissapeard when turning away from the house (turning at the spot).

Trying to prove ?  nothing.  Just saying that the VPS system had more sensors, and that my MA height IR sensor does work in the dark, as shown in the video.

Yep, baro sensor has no connection to the GPS module. Did i mention anything about that?

And, i will not try to fly my SPARK in a pitch black room. Why should i do that ? 3D front sensing system is not a IR device so will not work in the dark.

cheers
JJB

JJB* Posted at 8-12 11:40
uh ?? have i been in any way dis-respectful to you?

As i said ; the VPS visual sensors does not work well in a pitch dark flight, so yes ofcourse the 3M indication dissapeard when turning away from the house (turning at the spot).

I never said you have been disrespectful - what an utterly bizarre comment.

You stated that "in the pitch dark night it is measuring the correct height" - the altitude is measured by the barometer.

How does a 3D sensing system on the Spark that consists of an IR module not be an IR device?

Try and fly safe now

JJB* Posted at 8-12 11:40
uh ?? have i been in any way dis-respectful to you?

As i said ; the VPS visual sensors does not work well in a pitch dark flight, so yes ofcourse the 3M indication dissapeard when turning away from the house (turning at the spot).

It’s hard to fly dji drone in pitch black as you will get continuous flashing from front and back leds lol .

Hello and good day. The VPS may not work well if the light is too weak or too bright. I would suggest changing to another open place with enough light and check if the error message will show once again. Also, I'll attach the DJI Mavic 2 user manual ( https://dl.djicdn.com/downloads/ ... Manual_v2.0_en_.pdf ) and a screenshot of VPS working conditions for your reference. Thank you.