Flying the Mini 4 Pro Indoors - ATTI Mode or Other Tips?

[rohmattullah]

Hey everyone,

I'm planning an indoor flight with my DJI Mini 4 Pro inside an auditorium and I could use some advice.

I've been doing some research, and the general advice seems to be that using ATTI mode is essential for indoor flights, mainly because there's no GPS signal available.

My main question is: How can I manually switch to ATTI mode on the Mini 4 Pro? I've been looking through the DJI Fly app settings, but I can't seem to find the option.

If manually enabling ATTI isn't possible on this drone, what are your best tips or alternative methods for flying smoothly and safely indoors? I'm open to any suggestions on how to get more freedom of movement while keeping it under control.

Thanks in advance for your help!

 

[AeroJ]

On a Mini4P Atti is only a mode that it goes into when GPS signal doesn't meet minimum requirements - AFAIK it is not manually selectable using the regular controller / software.

However that should not cause you great problems flying indoors IF you do the obvious things before you take off like disabling RTH on signal loss (set to hover instead), set it to land in place at critical power level and perhaps even limit altitude to lower than the height of the area you are flying in.

It might be worth considering prop guard kits if you must fly in proximity to walls and ceiling and up stairs etc, and certainly initially Cine mode is a sensible choice for speed. You could even tweak your expo controls so that larger stick movements still result in quite minimal craft movement.

If you do enter ATTI mode, light and floor patterning are your best friends. If you have both, the visual sensing should be good enough to hold position and altitude, but as soon as one or other disappears you may end up drifting, and be aware that the drone itself will create a lot of turbulent air in an enclosed environment that will mean drifting does happen even in what may seem to be a windless space.

Try and position yourself in the room so that your controller always has direct line of sight with the drone. Amazing though Occusync 4 is if you drop down behind a few trees for a second, the effect is rather more dramatic if there are ever a couple of brick walls between the flyer and you. And that's why we need to make sure we don't RTH on signal loss via an ascent into the ceiling !

Lastly you can decide what you want to do about obstacle avoidance. In enclosed spaces, 'bypass' is not always the best action here - 'brake' is usually safer. Or you could turn it off, both to halt that annoying beeping you'll hear a lot of if you leave it on or don't turn it down in the RC settings, but obviously with all the additional risks that come with that lack of sensing.

I'm sure there is other stuff I have left out, but other people can chime in with that.

 

[EyesWideShut]

I have no experience with a Mini 4 Pro so someone will be along shortly to advise.

I have flown in ATTI mode successfully and safely many times over the past 15 years with only one problem. It's if the drone switches between modes when flying and you are not prepared for the different flight characteristics. Also being in a well lit area helps with consistent positioning.

 

[Meta4]

I've been doing some research, and the general advice seems to be that using ATTI mode is essential for indoor flights, mainly because there's no GPS signal available.


My main question is: How can I manually switch to ATTI mode on the Mini 4 Pro? I've been looking through the DJI Fly app settings, but I can't seem to find the option.

DJI hasn't made consumer drones with user-selectable Atti Mode for many years.
Atti Mode is what you have when your drone doesn't have GPS reception (and is unable to use the downward-facing sensors to maintain horizontal position).
Atti Mode = GPS Mode without GPS and without VPS
If you have no GPS but VPS is working, your drone will be in Opti Mode.

If manually enabling ATTI isn't possible on this drone, what are your best tips or alternative methods for flying smoothly and safely indoors? I'm open to any suggestions on how to get more freedom of movement while keeping it under control.

You should go to the auditorium and test to see if the building actually blocks GPS reception and if VPS will help or not.
If you can't use Opti Mode and would be flying in Atti Mode, your drone will maintain height, but not horizontal position.
It won't have any brakes and will continue to slide through the air after you centre the joysticks.
It also won't have any obstacle avoidance.
In that state, flying close to obstacles would be risky.
You would have to fly slowly and use gentle backwards control to bring it to a stop.
You would really need some practice, because the first time, it's going to be quite different from what you are used to.

 

[rohmattullah]

On a Mini4P Atti is only a mode that it goes into when GPS signal doesn't meet minimum requirements - AFAIK it is not manually selectable using the regular controller / software.

However that should not cause you great problems flying indoors IF you do the obvious things before you take off like disabling RTH on signal loss (set to hover instead), set it to land in place at critical power level and perhaps even limit altitude to lower than the height of the area you are flying in.

It might be worth considering prop guard kits if you must fly in proximity to walls and ceiling and up stairs etc, and certainly initially Cine mode is a sensible choice for speed. You could even tweak your expo controls so that larger stick movements still result in quite minimal craft movement.

If you do enter ATTI mode, light and floor patterning are your best friends. If you have both, the visual sensing should be good enough to hold position and altitude, but as soon as one or other disappears you may end up drifting, and be aware that the drone itself will create a lot of turbulent air in an enclosed environment that will mean drifting does happen even in what may seem to be a windless space.

Try and position yourself in the room so that your controller always has direct line of sight with the drone. Amazing though Occusync 4 is if you drop down behind a few trees for a second, the effect is rather more dramatic if there are ever a couple of brick walls between the flyer and you. And that's why we need to make sure we don't RTH on signal loss via an ascent into the ceiling !

Lastly you can decide what you want to do about obstacle avoidance. In enclosed spaces, 'bypass' is not always the best action here - 'brake' is usually safer. Or you could turn it off, both to halt that annoying beeping you'll hear a lot of if you leave it on or don't turn it down in the RC settings, but obviously with all the additional risks that come with that lack of sensing.

I'm sure there is other stuff I have left out, but other people can chime in with that.

Hey @AeroJ ,

Thanks for the tips earlier! I gave it a try, but I noticed the drone drifts a lot. Sometimes it even starts to descend by itself.

My guess is that the obstacle avoidance system is causing this. Can we completely disable the sensors to see if that fixes the drifting issue?

 

[rohmattullah]

DJI hasn't made consumer drones with user-selectable Atti Mode for many years.
Atti Mode is what you have when your drone doesn't have GPS reception (and is unable to use the downward-facing sensors to maintain horizontal position).
Atti Mode = GPS Mode without GPS and without VPS
If you have no GPS but VPS is working, your drone will be in Opti Mode.


You should go to the auditorium and test to see if the building actually blocks GPS reception and if VPS will help or not.
If you can't use Opti Mode and would be flying in Atti Mode, your drone will maintain height, but not horizontal position.
It won't have any brakes and will continue to slide through the air after you centre the joysticks.
It also won't have any obstacle avoidance.
In that state, flying close to obstacles would be risky.
You would have to fly slowly and use gentle backwards control to bring it to a stop.
You would really need some practice, because the first time, it's going to be quite different from what you are used to.

Hi @Meta4 ,

I tried flying in the auditorium, and it was tricky!

The drone wouldn't let me get close to the ceiling or walls—I guess the sensors were working overtime. Because of that, getting any decent shots was out of the question.

Curious to know, do you fly indoors often? What's your usual setup or workflow when you do?

 

[Meta4]

Curious to know, do you fly indoors often? What's your usual setup or workflow when you do?

I don't fly indoors but I started flying back when DJI drones had a switch which allowed you to fly in atti mode when you wanted to.
I used to do it often but never anywhere near obstacles.

 

[AeroJ]

My guess is that the obstacle avoidance system is causing this. Can we completely disable the sensors to see if that fixes the drifting issue?

What does the manual say ?! You have read that, right ?!

 

[Felix le Chat]

Hey @AeroJ ,

Thanks for the tips earlier! I gave it a try, but I noticed the drone drifts a lot. Sometimes it even starts to descend by itself.

My guess is that the obstacle avoidance system is causing this. Can we completely disable the sensors to see if that fixes the drifting issue?

You didn't mention whether you managed to get any kind of satellite reception during the test flight. If you did: it's likely to have been sporadic and have dropped out at times - that's when ATTI mode kicks in and your drone gets squirrelly (handling becomes unpredictable and challenging).

If it was also descending (or climbing) without stick input, the VPS probably didn't have enough available light to provide a positioning fix... or the floor surface didn't have enough contrast for the VPS to lock on to. Solution: see if the individual in charge of the venue can increase the ambient light levels - that might give the VPS enough to work with.

The O/A sensors are doing what they're supposed to and saving your drone from piling itself into the walls. I'd leave them on if I were you.

Also: before you fly: check that the compass isn't getting too much interference from metal fixtures in the structure: take a look at the orientation arrow displayed on the map screen - it shows you which direction the control app thinks the nose of the drone is pointing... if it is different to the actual direction the drone's pointing in: there's a chance you'll end up with a yaw error (compass deflection) which will send your drone off on a wild journey of its own that you won't be able to control.

Get a set of prop guards and fit them. Also flip the controller slider from 'normal' to 'cine' as soon as you get your bird in the air.

 

[offtheback]

Hey everyone,

I'm planning an indoor flight with my DJI Mini 4 Pro inside an auditorium and I could use some advice.

I've been doing some research, and the general advice seems to be that using ATTI mode is essential for indoor flights, mainly because there's no GPS signal available.

My main question is: How can I manually switch to ATTI mode on the Mini 4 Pro? I've been looking through the DJI Fly app settings, but I can't seem to find the option.

If manually enabling ATTI isn't possible on this drone, what are your best tips or alternative methods for flying smoothly and safely indoors? I'm open to any suggestions on how to get more freedom of movement while keeping it under control.

Thanks in advance for your help!

Not a great idea without outdoor practice near no obstacles.

 

[GadgetGuy]

Hey everyone,

I'm planning an indoor flight with my DJI Mini 4 Pro inside an auditorium and I could use some advice.

I've been doing some research, and the general advice seems to be that using ATTI mode is essential for indoor flights, mainly because there's no GPS signal available.

My main question is: How can I manually switch to ATTI mode on the Mini 4 Pro? I've been looking through the DJI Fly app settings, but I can't seem to find the option.

If manually enabling ATTI isn't possible on this drone, what are your best tips or alternative methods for flying smoothly and safely indoors? I'm open to any suggestions on how to get more freedom of movement while keeping it under control.

Thanks in advance for your help!

You don't mention what the purpose of the indoor auditorium flight is.
As long as you are not intending on recording an event with people inside, and you have full control of the space for your intended flight, lighting and contrast are your best friends. Turn on all the lights to their brightest settings. If there is insufficient contrast on the floors for VPS to lock onto, bring along some patterned floor rugs and position them appropriately. Ideally, you want to still be in OPTI mode whenever GPS is lost, rather than full ATTI mode, as @Meta4 stated above in post #4.

 

[Dogpilot]

I have a device very similar to this one. It repeats the gps signal inside an enclosed space. I use it for maintenance on my aircraft avionics in hangers. Not very expensive if you want to do indoors flight.

GPS repeater on ebay

 

[Felix le Chat]

I have a device very similar to this one. It repeats the gps signal inside an enclosed space. I use it for maintenance on my aircraft avionics in hangers. Not very expensive if you want to do indoors flight.

GPS repeater on ebay

Very interesting addition to the comments. Thanks for this.

 

[GadgetGuy]

I have a device very similar to this one. It repeats the gps signal inside an enclosed space. I use it for maintenance on my aircraft avionics in hangers. Not very expensive if you want to do indoors flight.

GPS repeater on ebay

Unfortunately, while it will provide GPS, the GPS reading will not change while the drone flies around inside. It's ideal for functional testing indoors, but not useful for flying a drone around indoors, while navigating the space.

Can I fly a drone/UAV indoors using a GPS repeater?

GPS repeaters provide signal inside buildings or spaces where it may not normally be present. Does this allow a drone to operate indoors?

www.gps-repeaters.com

Could a drone be flown indoors using signal from a GPS repeater?

A single repeater unit, mounted 10 meters up in the ceiling, facing down, will provide signal over an area of around 35-40 meters diameter.

Thing is, wherever you are within the coverage area you will only pick up the (fixed) positional coordinates of the outdoor antenna: longitude, latitude, elevation = outdoor antenna location.

A drone can get confused, because when it moves it is still receiving the same GPS coordinates as if it was standing still.

So this doesn’t provide the means to navigate inside the building as the signal is the same wherever you are.

Signal from a repeater can be used for functional testing, but usually not for indoor flight/navigation.

 

[Felix le Chat]

Unfortunately, while it will provide GPS, the GPS reading will not change while the drone flies around inside. It's ideal for functional testing indoors, but not useful for flying a drone around indoors, while navigating the space.

Can I fly a drone/UAV indoors using a GPS repeater?

GPS repeaters provide signal inside buildings or spaces where it may not normally be present. Does this allow a drone to operate indoors?

www.gps-repeaters.com

Could a drone be flown indoors using signal from a GPS repeater?

A single repeater unit, mounted 10 meters up in the ceiling, facing down, will provide signal over an area of around 35-40 meters diameter.

Thing is, wherever you are within the coverage area you will only pick up the (fixed) positional coordinates of the outdoor antenna: longitude, latitude, elevation = outdoor antenna location.

A drone can get confused, because when it moves it is still receiving the same GPS coordinates as if it was standing still.

So this doesn’t provide the means to navigate inside the building as the signal is the same wherever you are.

Signal from a repeater can be used for functional testing, but usually not for indoor flight/navigation.

I did wonder about how the drone calculated it's local position in relation to the relay... was thinking in terms of one of the RTK rover units, which I guess might be a viable option with one of the RTK-enabled drones. Thanks for the clarification.

 

[GadgetGuy]

I did wonder about how the drone calculated it's local position in relation to the relay... was thinking in terms of one of the RTK rover units, which I guess might be a viable option with one of the RTK-enabled drones. Thanks for the clarification.

I was disappointed myself to discover that it won't work for navigating inside, but it will work to test DJI Custom Unlocks indoors, that otherwise require taking the drone outside to test, when a Home Point setting is required before they will work.

 

[Dogpilot]

I am not sure which one you have, but mine, which is a decent unit. I have to use decent gear, I have a Federal license to work on Avionics in aircraft. It works quite well. I had to go out to the hanger today to fetch one of the nav cards to log some stuff. So I brought it home. My house is cut into the rock of the mountain. So the lower story is underground. Seems to work quite well for me.

Sorry about the crappy pics:

 

[Meta4]

Seems to work quite well for me.

But what does that mean?
When you move the GPS receiver 5 metres, do the coordinates show that?
Or do they stay the same because the repeater is just rebroadcasting the coordinates for the location of the static repeater?

 

[Dogpilot]

You know, I didn't look at the actual coordinates, except on the Garmin. The drone was quite happy flying around the basement area without issues. It showed a strong signal, where there was none before. It was able to stable hover, climb up to the ceiling and maneuver in through doorways and so on. It was like it was outdoors. I have used this with my starting with the Mavic 2 Pro and the 3 series. We use slightly more expensive units underground in the mines for LIDAR mapping of drifts. I would go and set it up again, but it is raining here now. If you want to fly, this works.

 

[GadgetGuy]

You know, I didn't look at the actual coordinates, except on the Garmin. The drone was quite happy flying around the basement area without issues. It showed a strong signal, where there was none before. It was able to stable hover, climb up to the ceiling and maneuver in through doorways and so on. It was like it was outdoors. I have used this with my starting with the Mavic 2 Pro and the 3 series. We use slightly more expensive units underground in the mines for LIDAR mapping of drifts. I would go and set it up again, but it is raining here now. If you want to fly, this works.

Nothing beats first hand experience. However, I strongly suspect the VPS system is the one controlling your drone indoors in a well lit area. Try flying inside completely in the dark to really test the GPS ability to navigate without VPS. The GPS coordinates are fixed to the location of the external antenna with any device like this, and should not change unless the drone itself is actually independently receiving GPS.

Post #14 above was taken directly from the web-site of high end GPS repeater systems vendor which clearly describes the purpose and the limitations of all GPS repeater systems, especially as it relates to drone flights indoors.

=====

"Wherever you are within the coverage area you will only pick up the (fixed) positional coordinates of the outdoor antenna: longitude, latitude, elevation = outdoor antenna location."

“A drone can get confused, because when it moves it is still receiving the same GPS coordinates as if it was standing still.

“So this doesn’t provide the means to navigate inside the building as the signal is the same wherever you are.”

“Signal from a repeater can be used for functional testing, but usually not for indoor flight/navigation."