control and downlink frequency+4G control

[Bob IBV]

Bob,
According to: DJI (company) - Wikipedia -
Dà-Jiāng Innovations Science and Technology Co., Ltd (Chinese: 大疆创新科技有限公司; doing business as DJI) is a Chinese technology company headquartered in Shenzhen, Guangdong. It manufactures unmanned aerial vehicles (UAV), also known as drones, for aerial photography and videography, gimbals, flight platforms, cameras, propulsion systems, camera stabilizers, and flight controllers.

I assume that should cover most of the the Uav area.
However, it doesn't answer my question;-)

 

[Dave Pitman]

Does control over 4g require 2 network accounts, 1 for the RC and one for the craft?

 

[Dr Jon]

Yes but we are using PAYG for development phase using 4G we get 10GB for 40Yuan valid for 1 month. On the version to be sold to customers they will need to provide SIM themselves. As this will mostly be sold to operators or their contractors I'm sure that will be free to themselves. If i was doing it under contract i would charge for bandwidth used as an extra cost.

On a 15 minute flight we used only 1GB as it was given TAP fly and only updates and video was transmitted from the FPV camera. The main camera was recording to SD card and the downlink was set to lowest possible transmission rate but the final customer version will be at maximum camera recording rate.

So far we found the video feed using an X4S set at 4K was excellent and more than the customer could expect to get. When we get the code stable we will use a X5S as an alternate camera as the zoom lens would be useful in some situations.

 

[ringolong]

It looks like some good work is going on here! I just read that the i2 and the sdk had this capability today.

I did not think that there would have to be a connection dongle in the radio, and another sim in the i2. I was hoping that there could be a sim in the i2 and use a device that had 4g could be used.

What are you guys developing in? iOS and Android, or just one for now?

I am going to dig a little into the sdk to see what dji is providing.

 

[Dr Jon]

For our proposed commercial offer we need to takeoff at a given location using the R/C (after doing the normal calibration of compass etc). This will be completed by a qualified CAA UAV pilot, but once airborne and in stable flight the Inspire would then be controlled by an expert located at some other location. Download feed to local site would be FPV only (just in case) the video downlink and control would be at remote location. Once the Inspire had completed its mission or new batteries are required the Inspire would be handed back to the local control. We plan this to be a phone call and formal handover not just switch off the 4G.

Also

1. Customer has choice not to have video saved to CINESSD and remote recording only
2. Mission can be pre configured (similar to DJI GS)
3. In case of loss of 4G the Inspire will revert to R/C if possible, if not will hover until it is synched or when battery is low it will land. (we use a GPS tracker )
4. We may be breaking the CAA rules as the Inspire may fly out of LOS
5. There are some other "customer requirements" but these are subject to NDA

We are currently only developing in iOS but will consider Android but security of Android is a big concern. We did at first consider using an iPad as the base and a dongle in the Inspire. Found the encryption and other software in the R/C was too much to have to add to the code we are working on. Also would loose the "sticks" and other control functions built in to both code and physical R/C. We did look at doing all this by FPV headset but placed this "on hold" for the time being to get first release of code in customer hands and get feedback.

Planned demo is scheduled for 3rd February and everything looks on track to be ready for this. A few minor bugs associated with handover during loss of transmission from either R/C or 4G. Also need to add some more code to defeat some of the DJI standard code.

Trying to keep all code such that future DJI API are exploited and minimum new code is added.

Once we have the commercial offer sorted we plan to offer some of the code as to the Inspire owners to simply use the 4G instead of the R/C standard radio. We have already tried this with some excellent results and distance of transmission. The 4G is much more stable and never a single drop out even during handovers between base stations.

 

[Dave Pitman]

Interesting. Are you saying that one of the options is to stream to 4g instead of recording to ssd? Depending on format can't that range up to 400+ GB for a couple of flights. Is that even possible?

 

[Dr Jon]

The stream is output to an external hard disk so storage is not an issue. The down link is set on the R/C and is the same speed as used on the 4G. We have an API interface that can overcome this limitation at a later release but want to get the code in customer hands before we waste too much time on quality that is not required. Don't forget the "output" would be viewed on an external HDMI monitor and for now 1080 is okay. Don't forget streaming on the Inspire is already a "standard" offering we simply divert this to the 4G.

Concerns are that if recorded to CINESSD this could be viewed by "others" if Inspire is lost. !!!

 

[Dave Pitman]

Ah, okay, I understand now. Since you mentioned cinessd I thought you were saying you were going to stream and remotely record cinema dng 5k video and I was thinking that was nuts, lol ! Also, it sounds like your client doesn't even trust their pilot in the field.
Interesting project.

 

[Dave Pitman]

I wanted to mention that the video downlink is not recored to the ssd anyway. It is recorded to the smart device connected to the RC. Much larger files are recorded to the ssd if the record function is triggered. This is different than the video downlink.

 

[Dr Jon]

It's not about trust but the need to being approved , classified and certified at a specific security level. You may have guessed it's not for a civilian entity.


Sent from my iPad using InspirePilots

 

[Bob IBV]

The stream is output to an external hard disk so storage is not an issue. The down link is set on the R/C and is the same speed as used on the 4G. We have an API interface that can overcome this limitation at a later release but want to get the code in customer hands before we waste too much time on quality that is not required. Don't forget the "output" would be viewed on an external HDMI monitor and for now 1080 is okay. Don't forget streaming on the Inspire is already a "standard" offering we simply divert this to the 4G.

Concerns are that if recorded to CINESSD this could be viewed by "others" if Inspire is lost. !!!

It's great to follow as more details are revealed. In some countries none LOS flights are not a problem with permission. For us making remote inspection and survey work the 4g mainly helps us to solve penetration issues in the hilly forest areas and resulting range limitations. It also adds extra safety.
I hope we can test this option soon!;-)

 

[rulppa]

Any updates with this?

 

[Dr Jon]

Customer demo scheduled for 4 Feb,, right now its CNY so all my staff are away at their hometowns

 

[NickU]

If they're worried about aircraft local media being viewable, then they need to be aware of the 'black box' flight log recorder in the aircraft (hard wired sd card). That contains several detailed flight logs and, certainly on other DJI drones, some stills from various points in the flight... sometimes take-off, sometimes landing.

I've heard that some countries will not allow use of DJI drones in classified areas because of the internal logs/pics and their potential to be sent back to DJI's servers.

 

[Dr Jon]

Yes we fixed this... automated the process that once we go in to landing mode we copy the DAT files to our own SD card and deleted those on the internal SD card. If we need to ship the I2 back to DJI for any reason we have to reinstall the original code anyway as DJI wont touch the APP we created. There will be no DAT files. We also had to a workaround for some of the DJI code that enforces flight restrictions as we could be flying in'red' zones

 

[NickU]

Hmm, what about if the landing mode isn't engaged and the aircraft crashes for some reason, then the internal is still available...

 

[Dr Jon]

I2 is fitted with a GPS tracker, the location is tracked whilst in flight and the location of crash situation is known to the "on site" pilot.

 

[NickU]

So, secure enough basically. It sounds an interesting project all round - good luck with it, and hope your demo goes well!

 

[Dr Jon]

For the last 10 days i have been flying my I2 using 4G only and a hidden benefit is you don't need line of sight so where i used to loose signal before it doesn't happen now. I can fly behind buildings over the other side of mountains and its still 100%. You do need to be a little careful when you get BS handover as you can loose contact for 500ms. But the I2 doesn't enforce RTH for such a small break in transmission. Obviously filming continues as is goes to SD card

One minor issue is you cant fly very high as the 4G is terrestrial focused so at about 200m you begin to get into issues. For my project this is not an issue, but the fly high guys cant use this..

 

[rulppa]

To be able to control drone with video feed (dji brand) over 4G is the thing i'm waiting for, when this is available i will make my i2 order. Otherwise, i will just stick with phantom series., Kinda frustrated fiddling with remotes, antenna boosters, different panels or airside-boosters. It's never ending route, 4G would simply stop this nonsense..