Tau Labs OP CC for camera mount stabilization

[jes1111]

ah - okay - I see what you're asking now - sorry

As far as I understand - no, there shouldn't be any problem using it that way at the moment, just so long as you know what's what within the GCS configuration. Set it up as a "Custom" aircraft type - three channels (servos), each responding (with a "127" value in that column/row) to Roll, Pitch and Yaw commands.

Stabilisation settings are likely to be the cause of confusion. I'm going to find out on that one and come back to you

 

[Bartman]

ok, thanks! at least we're working on the same problem now.

Here's another problem I've encountered in the last few minutes....maybe Crash with his MK FC knowledge will be able to explain this one.....

I'm trying to wire my camera mount servos and video Tx to a separate 6 volt pack while pulling servo signals from the FC. I've always thought battery and signal could come from different sources when it comes to servos. THe problem is though that It's not working. Can there be any logic in the servo outputs on the FC that say if there's no power being drawn then no signal will be sent?

 

[BorisS]

Bart

since I have a similar setup like the one you are going for and it is working, just not with a 6 volt pack but a Ubec powering the servos, I doubt that it would be different with your FC.

 

[Pano-Dirk]

Bart, you have to connect minus (ground) from the second battery and the main battery. Ground from the power supply for the servos and ground for the servo signal have to be on the same level.

I am using this with 7,4 Volt for the servos and it is working fine.
(high voltage servos)

 

[jes1111]

Bart, you have to connect minus (ground) from the second battery and the main battery. Ground from the power supply for the servos and ground for the servo signal have to be on the same level.

I am using this with 7,4 Volt for the servos and it is working fine.
(high voltage servos)

Yep - just like a car - one common ground for everything - very important for a well-sorted system

 

[Bartman]

thanks guys, nice to find the answer first thing in the morning.
hit it early this morning and replaced the ground wires i cut from the harness last night. i used two 24" y-extensions and modified them for the servo wires. tied them together at a deans connector then just pulled what wasn't needed for the signal branches and yanked the signal wire in the battery branches
pic below
View attachment 690

i'm going to fly with a camera after breakfast so we'll see if I'm in a good place for further tweaking or if I'm way off.

thanks again.

 

[DennyR]

This idea does have the potential to make a very serious camera mount IMU. With a 12 bit ADC you could have 4960 possible steps of resolution. May I ask what is wrong with just taking the conventional heli or fixed wing set-up and just placing the IMU on the camera base plate so it thinks it is stabilising an aircraft in three axis.

 

[Bartman]

This idea does have the potential to make a very serious camera mount IMU. With a 12 bit ADC you could have 4960 possible steps of resolution. May I ask what is wrong with just taking the conventional heli or fixed wing set-up and just placing the IMU on the camera base plate so it thinks it is stabilising an aircraft in three axis.

DennyR
I wish I understood where the electrons go when they enter a flight controller or servo but I just don't. Is the 12 bit ADC a part of the OP coptercontrol or are you saying it would be an upgrade to it?
I think it should be an easy application as well but Pano-Dirk has tried and given up so I'm wondering where the challenge is? I've got a paying gig on the 15th so I'm using MK camera control just so I have something working on that day but then it will be back to the CC camera scheme.
Seems pretty straightforward but is it?

 

[jes1111]

It's certainly possible (with a second, separate Tx/Rx) but, like I said earlier - stabilisation settings need to be tuned to the application. I'd be interested to hear what problems Pano-Dirk encountered. Nobody in the core team has tried this yet - they've simply pronounced it "possible".

It's probably also possible with a single Tx/Rx but that would need some fiddling in UAVobjects, me thinks.

 

[Pano-Dirk]

Yes, I used a seperate RX only for the CC board. The problem was, to find the stabilisation settings. The stabilisation was to slow, then to fast, then the camera moved a little bit to much and so on. It was not possible for me to find the right values, that the camera is looking in one direction also when the mount was moved a little bit. Perhaps I have not configured all settings in the correct way.

Perhaps it is possible.

 

[jes1111]

Problem is I don't think we should be asking the core team to devote any time to this right now - they've got more than enough on their plates. Have you tried flying a quad with the CC? I'm guessing it would help to become more familiar with the tuning parameters. In basic terms I think the objective would be to tune it as if it was a very fast-reacting aircraft, i.e. the correction of a rotational error is almost instant. Mode should be "attitude", definitely no Feedforward. Remember that all the tuning will be much closer to that of a plane (with a single control surface for each axis) than a quad - so maybe search the OP forum and wiki for clues on how planes are being set up? I'm not in the air myself yet, and anyway I only have one CC board, so it'll be a while before I'm able to test this myself.

 

[Bartman]

here's the mixer table that Peabody124/James suggested

http://forums.openpilot.org/topic/5...tion-with-tilt/page__view__findpost__p__21244

Bart

 

[jes1111]

Latest report from the front:

Question: Sounds good to me! So am I right in thinking that there will be just the three instances? - CameraDesired.Pitch .Roll and .Yaw? And if a GCS module wants to do anything else (like focus, shutter release, etc.) we'd use the "Accessory" objects?

Answer: Yeah - there will hopefully be an arbitrary number of extensible controls. Stac is working on multi receiver and GCS support (so for example fly with TX, control camera through GCS). For outputs there will be the three axes like you said.

(My) translation into English - the core team are (as always) doing a thorough, professional job on this, not just "hacking the code to make it work" - we can expect a super-flexible system that supports many permutations. We just have to be patient

 

[DennyR]

Bart

The gyro which is the sensor that measures the (angular rotational disturbance) outputs a small mv. change from it's nominal analog output at rest. With an 8 bit Analog to Digital converter you get 1024 steps and with a 12 bit you get 4096 thus creating better resolution. What you do with that signal afterwards is a matter for those who designed the system and write the code. IMHO the CC board has an impressive set of components which could be just as useful as a stand alone camera platform as it is a FC controller. I have already started playing. I see the CC board as the missing link that we need to create the ultimate stand alone solution. Yes a separate TX or Rx or a modified TX that has an extra stick like my 14 MZ system. With different gyros that have much greater sensitivity it is possible to match the performance that I paid many thousands to achieve just a few years ago. For example a Fiber optic gyro (one axis) could set you back 5,000 usd but an invensense IDG 1150 two axis is just 6 usd. The IDG does not have the range but the sensitivity is not far short.

 

[matwelli]

here's the mixer table that Peabody124/James suggested

http://forums.openpilot.org/topic/5...tion-with-tilt/page__view__findpost__p__21244

Bart

Hey Bart, i have played with the mixer ALOT for multis, let me know how you get on, if i have time i will have a play and see if i can get a cc to do stand alone camera comp

 

[Bartman]

Thanks Matt. I really appreciate it.
I had been gearing up for some video work on Monday but they've postponed the project so I'm going to take a break for a few days then start over on Sunday. That means I'm going to make my own camera mount and try again to do the CC stabilization trick. If I can get the mount built by Tuesday or so I'll be back to tinkering in GCS middle of next week.
I've learned a ton in the last couple of weeks trying to get an averticalview.com mount to come together but I think I can do better with my own stuff.
Regards,
Bart

 

[peabody124]

So for anyone that wants to test camera stabilization and has a quad with a mount please PM Dankers and I on the OP forums and ask for access to the testing group. I'm going to post a test build there.

As for a standalone stabilizer it should work out of the box, but will require some work to find good settings. I'm not 100% the traditional dual loop controller structure is what you want for this circumstance. If you run into issues PM me on OP and I'll see it more quickly. I'll try and follow this though. Here was a starting mixer I posted earlier on OP
http://forums.openpilot.org/topic/5...tion-with-tilt/page__view__findpost__p__21244

 

[Bartman]

I may be ready as early as Wednesday to have a mount worth testing. My current mount is more mods than original parts so I'm starting over.
I had things basically working but the two axis stabilization wasn't proportional, it would only react full deflection in either direction as I moved the CC board.
Thanks peabody
Bart

 

[peabody124]

I may be ready as early as Wednesday to have a mount worth testing. My current mount is more mods than original parts so I'm starting over.
I had things basically working but the two axis stabilization wasn't proportional, it would only react full deflection in either direction as I moved the CC board.
Thanks peabody
Bart

That sounds like a flipped sign to me. Makes in unstable and causes exactly that.

 

[Bartman]

well, see that? we're making progress already.