Maximum Altitude Setting Not Working

[MRomine]

On my SC controller I have the Maximun Altitude set for 30m or 98 ft. On Monday I was shooting a job in Case D airspace that has an altitude restriction of 100 ft at the location where I was working. My SC contorler was not stopping the M2P at 30m in fact my flight records show that my maximun altitude that day was 115ft. Is there a setting that I'm missing or is there something defective with my SC?

 

[rangemaster728]

DJI drones are equipped with the so-called IMU, an acronym for "Inertial Measurement Unit". It is the heart of the flight controller that allows the drones like the Dji Mavic 2 to fly in a stable and safe way. Its main sensors are: accelerometer, gyroscope, barometer and thermometer.

The barometer measures air pressure; its altitude indication (as calculated by the IMU and passed to the DJI app) shows height above the takeoff point.

While some have maintained that the GPS might also be (additionally) used in this calculation GPS altitude in DJI consumer birds is not as accurate as most of the high-end commercial drones. GPS is more accurate for horizontal positioning than vertical and will depend on the number of satellites locked.

Altitude indications via barometer - filtered thru the IMU - may also be subject to a sampling rate/integration time to smooth out the results. Some drones have dual barometers...and dual IMUs for increased accuracy and reliability.

The Mavic 2-series (along with some others) have some additional controls for precision altitude that uses downward sensors, but that is only functional up to about 8 meters...

Someone will inevitably point out it is the PIC’s responsibility to monitor altitude and not rely on the controller, but I’m not concerned about a 17-foot deviation being a regulatory problem.

I would recommend a flight test; using the same settings (not in a 100-foot Class D) try to go to the limit and see if it stops...then take a screen shot. Hover at 3 ft...make sure the indicated altitude is 3’ (-ish).

Next, review the flight logs and see if that value upon reaching the altitude limit and 3 ft. hover agree...

 

[MRomine]

DJI drones are equipped with the so-called IMU, an acronym for "Inertial Measurement Unit". It is the heart of the flight controller that allows the drones like the Dji Mavic 2 to fly in a stable and safe way. Its main sensors are: accelerometer, gyroscope, barometer and thermometer.

The barometer measures air pressure; it’s altitude indication (as calculated by the IMU and passed to the DJI app) shows height above the takeoff point.

While some have maintained that the GPS might also be (additionally) used in this calculation GPS altitude in DJI consumer birds is not as accurate as most of the high-end commercial drones. GPS is more accurate for horizontal positioning than vertical and will depend on the number of satellites locked.

Altitude indications via barometer - filtered thru the IMU - may also be subject to a sampling rate/integration time to smooth out the results. Some drones have dual barometers...and dual IMUs for increased accuracy and reliability.

The Mavic 2-series (along with some others) have some additional controls for precision altitude that uses downward sensors, but that is only functional up to about 8 meters...

Someone will inevitably point out it is the PIC’s responsibility to monitor altitude and not rely on the controller, but I’m not concerned about a 17-foot deviation being a regulatory problem.

I would recommend a flight test; using the same settings (not in a 100-foot Class D) try to go to the limit and see if it stops...then take a screen shot. Hover at 3 ft...make sure the indicated altitude is 3’ (-ish).

Next, review the flight logs and see if that value upon reaching the altitude limit and 3 ft. hover agree...

Thanks for taking the time to write and share all that information. I did not know much of that and your little test suggestion is good too!

I appreciate it.

 

[Meta4]

On my SC controller I have the Maximun Altitude set for 30m or 98 ft. On Monday I was shooting a job in Case D airspace that has an altitude restriction of 100 ft at the location where I was working. My SC contorler was not stopping the M2P at 30m in fact my flight records show that my maximun altitude that day was 115ft. Is there a setting that I'm missing or is there something defective with my SC?

The controller is not what stops the drone going higher than the Max Altitude Limit (which is stored in the drone itself).
It sounds like the Max Altitude Limit was not what you thought it was.
Post your flight data which will have a lot more information to help see what was really happening.

 

[MRomine]

The controller is not what stops the drone going higher than the Max Altitude Limit (which is stored in the drone itself).
It sounds like the Max Altitude Limit was not what you thought it was.

It may get stored on the aircraft as you say but why is there an option in the GO4 app to set a Maximum Altitude limit in the first place if it does not actually work? That makes no sense at all.

 

[Meta4]

It may get stored on the aircraft as you say but why is there an option in the GO4 app to set a Maximum Altitude limit in the first place if it does not actually work? That makes no sense at all.

The reason you can set the Max Altitude in the app is that there's nowhere else you can change it.
To confirm whether your drone failed to stop at your Max Altitude limit we'd need to see what the limit was set to in your recorded flight data.
If you want to get to the bottom of this mystery, post your flight data.

 

[MRomine]

If you want to get to the bottom of this mystery, post your flight data.

Ok, so how do I send that one specific flight record from the SC? Thanks

 

[Meta4]

Ok, so how do I send that one specific flight record from the SC? Thanks

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.

Details for doing this from the SC are toward the bottom of the instructions

 

[MRomine]

Details for doing this from the SC are toward the bottom of the instructions

Thank you for trying to help but his instructions are not matching up with my SC and the DGI GO4 app. What I am seeing is entirely different. His instructions must be for an earlier version.

 

[Meta4]

Thank you for trying to help but his instructions are not matching up with my SC and the DGI GO4 app. What I am seeing is entirely different. His instructions must be for an earlier version.

If you can find the .txt file, just post that.
It would be very unusual for the Max Altitude limit to be bypassed so I'd be interested to look into this further.

 

[MRomine]

If you can find the .txt file, just post that.
It would be very unusual for the Max Altitude limit to be bypassed so I'd be interested to look into this further.

I'm gong to have to get the SC manual out and read it because I am not seeing a way to do this. I'm sure there is a way I just do not know how.

 

[Meta4]

I'm gong to have to get the SC manual out and read it because I am not seeing a way to do this. I'm sure there is a way I just do not know how.

Have you checked the Max Altitude setting with the drone connected to the controller?

 

[MRomine]

Have you checked the Max Altitude setting with the drone connected to the controller?

Yes, it is set to 30m.

 

[MRomine]

If you can find the .txt file, just post that.
It would be very unusual for the Max Altitude limit to be bypassed so I'd be interested to look into this further.

Ok, I think I found the .txt file that I need. I am attaching it to this post.

 

[Meta4]

On my SC controller I have the Maximun Altitude set for 30m or 98 ft. On Monday I was shooting a job in Case D airspace that has an altitude restriction of 100 ft at the location where I was working. My SC contorler was not stopping the M2P at 30m in fact my flight records show that my maximun altitude that day was 115ft.

That's the correct file and your flight data looks like this: DJI Flight Log Viewer - PhantomHelp.com

It seems that you've confused RTH height with the Max Altitude limit.
Your RTH height was set to 98 feet but unless you've changed the default Max Altitude limit it will still be 400 ft.

Is there a setting that I'm missing or is there something defective with my SC?

The setting you are missing is at the bottom of the screen here (on a non-smart controller).
Like the RTH height, the Max Altitude limit is stored in the drone so it has to be connected to make changes.

 

[MRomine]

That's the correct file and your flight data looks like this: DJI Flight Log Viewer - PhantomHelp.com

It seems that you've confused RTH height with the Max Altitude limit.
Your RTH height was set to 98 feet but unless you've changed the default Max Altitude limit it will still be 400 ft.

The setting you are missing is at the bottom of the screen here (on a non-smart controller).
Like the RTH height, the Max Altitude limit is stored in the drone so it has to be connected to make changes.

Interesting, I'm looking at my SC right now and both of those cells (RTH and Max Altitude) have 30m entered into them.

 

[Meta4]

Interesting, I'm looking at my SC right now and both of those cells (RTH and Max Altitude) have 30m entered into them.

Is the drone connected?

 

[MRomine]

Is the drone connected?

Yes it is.

 

[Meta4]

Is the drone connected?

Well that's very unusual.
Unless you have changed the Max Altitude limit from the default setting it came with, it should still be at 400 ft.
If the limit was at 30 metres during the flight you posted, it would not have allowed the drone to exceed the limit.
It really looks like the limit is set higher than 30 metres.

Try changing the setting and doing a little testing.

 

[MRomine]

Well that's very unusual.
Unless you have changed the Max Altitude limit from the default setting it came with, it should still be at 400 ft.
If the limit was at 30 metres during the flight you posted, it would not have allowed the drone to exceed the limit.
It really looks like the limit is set higher than 30 metres.

I have not changed it. Is 30m the default setting? I did do a Firmware Refresh to both the drone and the SC tongiht. Would doing so reset it to a default setting?