just a quick question

[Dominic]

Hi All

I have wired the positive and negative ESC, feeds in to two clusters, so doing away with the need for a distribution board. Would this cause the bad status light to come on more often?? And how often should it come on??

This is our set up:

AD6 HL
DJI Wookong M
30amp ESC's
Torxpower motors
13/6.5 props

No vibration shows on video now as I have balanced the props. The ESC's are tucked between the main mount plates and the electrics are all under the bottom plate. I did this to keep the risk of noise down to a minimum! The IMU is directly in the middle and the GPS is 5" aft on the rear motor boom to the middle of the IMU.

The UAV, works well in 0 wind but even the slightest wind turns it in to a crazy machine and the white lights start, 2, then 3 lights at a time. in GPS, it wonders up to 1.5mtrs across and 1mtr up and down so it's hunting for a fix even though there are no red lights, so a good gps status!

Radio's
2.4ghz to operate the AD6.
2.4ghz to operate the gimble.
900Mhz video to ground live feed.

Hope you can help guys.

Thanks in advance for all your advise cheers Dominic

 

[Michael64]

A couple of question what are your gain settings set at and what is the All up flying wieght and one last thing what is the distance from center on motor across to center of motor shaft.
This info will help in helping give you info to try.

Michael64

 

[Dominic]

Hi Michael64

So the Pitch is 240% Role 240% Yaw 240% Vertical 250%

Attitude Gain 85% 85% weight is 10.5lb 4.76kg 723mm motor shaft two motor shaft

​

 

[Michael64]

Dominic
Yours is close to mine, you may try to up the yaw gain to about 280 and lower the vertical to 195-205. As far as pitch and roll you may need to up it a little to say 260-265. Now on the atti gains try them about 65 on both and see how that does. Also how is the IMU mounted, by that I mean mounted to the plate, also did you make sure the measurement you entered real close and with the right Positive and Negative numbers as well, you most likely have but worth asking.

Michael64

 

[quadcopters]

I would also agree the COG settings are very critical for good gps holding , I have experimented a lot with COG settings and it does make a difference .
And vertical gains does seem high , I have never had to go that high on vertical or Yaw so might be worth setting the Vertical on a dial on the radio so you can tune in flight .

Geoff

 

[Dominic]

Thanks loads Guys
We are going to work on it tomorrow. I will input the gains you have given me Michael and see how it goes. We will re-calibrate and re-do the C of G again to make sure we have not made any mistakes!

cheers Dom

 

[UAVproducts]

Like Geoff said. CG is very important. Change in CG changes the Z setting and that is the setting that needs full attention.

It would be nice if we could put the Z offset settings on a remote switch to make adjustments in flight. Hmmmmm.....something to request to DJI I think.

Post a pic of your setup if possible and that will help us get a better understanding.

 

[andrewrob]

Update

Ok we've done some further testing.

We have used the gain settings suggested above by Michael and its flying exactly the same as before so gains don't seem be the issue.
We adjusted the gains down until we got to 200% and didn't notice any difference at all.

We are also getting 2 white lights consistently even when hovering and 10 seconds after landing when the rotors aren't even spinning.
The white lights are worse since we lifted the IMU higher (as shown in the pictures below).

Could having the ESC input wires soldered together in a clump rather than on a distribution ring be causing interference with the IMU?

View attachment 3416View attachment 3417

 

[UAVproducts]

Ok we've done some further testing.

We have used the gain settings suggested above by Michael and its flying exactly the same as before so gains don't seem be the issue.
We adjusted the gains down until we got to 200% and didn't notice any difference at all.

We are also getting 2 white lights consistently even when hovering and 10 seconds after landing when the rotors aren't even spinning.
The white lights are worse since we lifted the IMU higher (as shown in the pictures below).

Could having the ESC input wires soldered together in a clump rather than on a distribution ring be causing interference with the IMU?

View attachment 4845View attachment 4846

Can you show us a screen shot of your XYZ offset values?

The reason I ask is if they are not set correctly you will be "chasing" the gains to no end. The XYZ numbers tells the DJI where the IMU is in relation to the true CG point. It uses the numbers in a Algorithm.

True CG point is where the frame will balance on all Axis's. That is in theory if you could put a rod with a swivel on it the frame would balance perfectly on all axis. Now that is a little extreme of course what we really want to work on is the Z axis.

Take a picture of your XYZ settings and a pic of the whole craft from the side and that should at least help us to get a general idea on the Z settings.

Hope that helps and makes sense. I'm still having my morning coffee so I might be a little slow.

 

[andrewrob]

Can you show us a screen shot of your XYZ offset values?

The reason I ask is if they are not set correctly you will be "chasing" the gains to no end. The XYZ numbers tells the DJI where the IMU is in relation to the true CG point. It uses the numbers in a Algorithm.

True CG point is where the frame will balance on all Axis's. That is in theory if you could put a rod with a swivel on it the frame would balance perfectly on all axis. Now that is a little extreme of course what we really want to work on is the Z axis.

Take a picture of your XYZ settings and a pic of the whole craft from the side and that should at least help us to get a general idea on the Z settings.

Hope that helps and makes sense. I'm still having my morning coffee so I might be a little slow.

Thanks, here you go. Ignore the fact that they are in red, the other laptop is the one we usually plug in so I've just keyed in the settings from that on mine
Forgot to say the camera isn't in it there as I'm using it to take the picture! Its a canon 550d which weighs around 600-700g
View attachment 3420View attachment 3419

 

[UAVproducts]

So where are you taking your Z measurement from?

Is that IMU mount very stiff. It can't move at all right?

 

[andrewrob]

The IMU mount is stiff
Where the yellow line intersects the red is the Z axis COG (as far as we can tell)
View attachment 3421

 

[UAVproducts]

That looks about right then. That would have been my guess.

The only other thing is RF interference of some kind because of the layout of hardware or power Dist. board.

 

[andrewrob]

The only thing that has changed in that respect since it was last working is the main power wiring. Before we were using a distribution ring, now we have all of the positive ESC wires soldered together in a bundle and all of the negative in a bundle. Could that increase interference in any way?

Thanks

 

[UAVproducts]

Yes, I'm sure it could. Especially if it was working fine before you changed it.

Why did you switch out the power Dist. board?

 

[andrewrob]

Just because it was a neater fit doing it that way. Dom is putting it back to a distribution ring now so will see how it fairs. Thanks very much for your help. We will hopefully be able to post up how its gone by the end of the day.

 

[andrewrob]

Went back to the distribution ring and its so much better now. Massive difference, thanks for your help.
Does anyone know if there are any issues with the latest DJI firmware at all? We are on Software 1.1 Firmware 4.2
but didn't want to update to the latest in case there were any issues with it.

Thanks