CS6 latest gain settings video

[RTRyder]

I had a chance to try out some different basic gain settings today along with having the ATTI gains adjustable from the TX. I think I've pretty much hit the optimum for the current setup, I don't see it getting much better than this although I can get a bit smoother on the sticks with a few more hours flight time on the CS. Still getting used to the size of this bird, it is substantially bigger than everything else I own or have flown and it does take a little getting used to.

Here's some clips form the last flight I did today while trying out a few different settings on the ATTI gain adjustment. Raw video from the Nex 5N only edited for run time, no stabilization added...

Ken

 

[Choppercam]

That is super smooth. Is that with the cinestar camera mount and wk stabilization?

Might have to sell my mk okto2!!!!!

Cheers. Tim

 

[BorisS]

Very nice KEN ! Hope i will be there soon !

Boris

 

[Siteline]

That's very very impressive!

 

[Droider]

Very nice ken.. whats your gimbal settings..
Do you have any gitter on the servos as its stood on the ground?

Dave

 

[BorisS]

Its a strage one today I dont have the jitter gitter on the ground. Gonna fly it later and see what happens !

Boris

 

[wbrown]

That is super smooth. Is that with the cinestar camera mount and wk stabilization?

Might have to sell my mk okto2!!!!!

Cheers. Tim

Amazing footage! Hearing alot of good things about the wookong!

Also what props did you settle with?

 

[RTRyder]

That is super smooth. Is that with the cinestar camera mount and wk stabilization?

Might have to sell my mk okto2!!!!!

Cheers. Tim

Current setup is the CineStar frame and camera gimbal mounting system with a Photohigher AV130 mount. The AV130 is powered by a CC BEC Pro at 6.2 volts and only the signal wire connected to the WKM for stabilization.

Very nice ken.. whats your gimbal settings..
Do you have any gitter on the servos as its stood on the ground?

Dave

No movement at all while on the ground although the servos do hum and whine which is normal for hi-res digitals. If you watch through to the end you can see after it lands the video is perfectly steady until my hand pushes the stop button on the camera. This one I can power up and leave it sit on the ground until well after it has acquired full GPS lock and the mount will never move. The Quad with WKM and 2 axis GoPro mount, also with Savox hi-res servos is the complete opposite, it hums, whines, twitches, drifts, and generally looks like it is incapable of staying steady. Once in the air it seems to settle down and I have gotten a lot of good video from it...

Amazing footage! Hearing alot of good things about the wookong!

Also what props did you settle with?

Currently using Graupner 11 x 5 on it. I've got a couple pairs of 4S 8000 mAh packs coming which is going to add some weight over the 4S 5000 pairs now in use. I'd like to get the weight up enough to use 12 inch props but it's not there yet, too much prop with not enough weight will give the WKM a bad case of the wobbles. Still have a lot of experimenting to do to find the best overall setup.

 

[GGoodrum]

Its a strage one today I dont have the jitter gitter on the ground. Gonna fly it later and see what happens !

Boris

Was the system initialized to where the red LED only flashes twice, once or not at all? For some odd reason, the twitches only start happening once the system sees enough sats that it is not flashing three times anymore.

Sidney says the engineers are working on it, but he's now off for the Thanksgiving holiday until next Monday. Unfortunately, that means I probably won't hear anything more before then. :upset:

Ken, just out of curiosity, what values are you using for the gimbal gains? Also, do you happen to know what the reduction ratios are for the AV-130?

-- Gary

 

[BorisS]

Hi Gary, the jitters came gradually during the flight and every further flight they were present from beginning, so the point of the sat lock being linked to it could be correct. Hmm it the GPS module absolutely necessary does the yaw gain need the digital compass. If someone knows that flying without the gps module works i would try it out.

 

[RTRyder]

Was the system initialized to where the red LED only flashes twice, once or not at all? For some odd reason, the twitches only start happening once the system sees enough sats that it is not flashing three times anymore.

Sidney says the engineers are working on it, but he's now off for the Thanksgiving holiday until next Monday. Unfortunately, that means I probably won't hear anything more before then. :upset:

Ken, just out of curiosity, what values are you using for the gimbal gains? Also, do you happen to know what the reduction ratios are for the AV-130?

-- Gary

I've got the gimbal gains set to 22 for both axis. Don't recall what the ratios are for the 130, I know the roll axis has changed from the first one I have to the second along with the change in servos. I seem to recall something like 5:1 for roll and maybe a bit less for tilt.

Ken

 

[GGoodrum]

I've got the gimbal gains set to 22 for both axis. Don't recall what the ratios are for the 130, I know the roll axis has changed from the first one I have to the second along with the change in servos. I seem to recall something like 5:1 for roll and maybe a bit less for tilt.

Ken

Thanks.

One thing I've noticed, in all my playing around with the gimbals, and several different mounts, is that the gains are basically a way to "tune" the outputs to the amount of reduction in each axis. With the gains at 20, it seems well matched to a direct-drive/1:1 setup. With a mount with about a 2-1/2 to 3:1 reduction, in the roll axis, I had to crank the gain up to about 42 in order to get it to react the same as a direct drive, with no reduction. What I do to check is hold the platform up, so that I can see some horizontal reference point, on the camera, or the platform. I then line this up with some horizontal reference several feet away, like the top of a cabinet, or bookcase. As the platform is moved, the two horizontal references should remain lined up. If the camera/platform is tilting left (counterclockwise...) from the external horizontal reference. the gain is too low. If it tilts the other way (clockwise...), the gain is too high.

I know that you and other "pros", like Tabb, get good video through a combination of smooth flying, belt-driven mounts, with lots of reduction and by having a wobble-free platform with great vibration dampening. Your mount is reacting very smoothly to gimbal output changes, mainly, I believe, because you have the gains dialed down pretty low, relatively speaking. I believe this is also why you don't see the drifting/hunting/twitching many of the rest of us are experiencing. Anyway, the CineStar's vibration isolation takes care of eliminating that as a factor in the equation, and you have been playing with the gains, etc., in order to take care of the wobble issue, so the rest of it is simply your superbly smooth flying skills. The net result is very smooth videos, where the camera basically just "slides" around, left and right, and front and back.

I have a theory, however, that it should be possible to achieve the same sort of smoothness, from the camera's perspective, by working on the gimbal's interaction with the MC's correction outputs. With the gains dialed in on my direct drove setup, I can move the platform all over the place, and the camera stays put. The reason is that with fast servos, and with zero reduction, the mount can react instantly to the changes in the gimbal outputs. With regular servos, however, there's a "stair-steppiness" to the servo movements, so it is not smooth. I found, however, that by using the newer 12-bit/hires-type servos, the movement is a whole lot smoother, maybe not perfect, but much better, nonetheless. I think what is needed is to use some reduction, via a belt drive, but not so much that there is too much of a speed penalty that reduces the quick react-ability that the direct drive exhibits. I'm still playing with this, but I think something around 2:1 will be a good compromise. this should smooth the action out, and still allow the camera platform to remain stationary.

Anyway, if my theory proves out, it won't matter what the platform is doing, the camera should stay "level". Not only does this mean that it's not so critical to dial out "wobbles", it also means you don't necessarily need to be a "pro-level" pilot in order to get decent video.

I hope to suss this out by this weekend. I received my 3328 motors and 40A HW ESCs today, so I will be finishing up my CS 6 build in the next couple days. I also have a two-axis mount that I am in the process of modifying to use a 2:1 belt drive, with the same ultra-fast 12-bit HS-7940TH servos I'm using on my direct-drive GoPro mount.

-- Gary

 

[RTRyder]

Thanks.

One thing I've noticed, in all my playing around with the gimbals, and several different mounts, is that the gains are basically a way to "tune" the outputs to the amount of reduction in each axis. With the gains at 20, it seems well matched to a direct-drive/1:1 setup. With a mount with about a 2-1/2 to 3:1 reduction, in the roll axis, I had to crank the gain up to about 42 in order to get it to react the same as a direct drive, with no reduction. What I do to check is hold the platform up, so that I can see some horizontal reference point, on the camera, or the platform. I then line this up with some horizontal reference several feet away, like the top of a cabinet, or bookcase. As the platform is moved, the two horizontal references should remain lined up. If the camera/platform is tilting left (counterclockwise...) from the external horizontal reference. the gain is too low. If it tilts the other way (clockwise...), the gain is too high.

I know that you and other "pros", like Tabb, get good video through a combination of smooth flying, belt-driven mounts, with lots of reduction and by having a wobble-free platform with great vibration dampening. Your mount is reacting very smoothly to gimbal output changes, mainly, I believe, because you have the gains dialed down pretty low, relatively speaking. I believe this is also why you don't see the drifting/hunting/twitching many of the rest of us are experiencing. Anyway, the CineStar's vibration isolation takes care of eliminating that as a factor in the equation, and you have been playing with the gains, etc., in order to take care of the wobble issue, so the rest of it is simply your superbly smooth flying skills. The net result is very smooth videos, where the camera basically just "slides" around, left and right, and front and back.

I have a theory, however, that it should be possible to achieve the same sort of smoothness, from the camera's perspective, by working on the gimbal's interaction with the MC's correction outputs. With the gains dialed in on my direct drove setup, I can move the platform all over the place, and the camera stays put. The reason is that with fast servos, and with zero reduction, the mount can react instantly to the changes in the gimbal outputs. With regular servos, however, there's a "stair-steppiness" to the servo movements, so it is not smooth. I found, however, that by using the newer 12-bit/hires-type servos, the movement is a whole lot smoother, maybe not perfect, but much better, nonetheless. I think what is needed is to use some reduction, via a belt drive, but not so much that there is too much of a speed penalty that reduces the quick react-ability that the direct drive exhibits. I'm still playing with this, but I think something around 2:1 will be a good compromise. this should smooth the action out, and still allow the camera platform to remain stationary.

Anyway, if my theory proves out, it won't matter what the platform is doing, the camera should stay "level". Not only does this mean that it's not so critical to dial out "wobbles", it also means you don't necessarily need to be a "pro-level" pilot in order to get decent video.

I hope to suss this out by this weekend. I received my 3328 motors and 40A HW ESCs today, so I will be finishing up my CS 6 build in the next couple days. I also have a two-axis mount that I am in the process of modifying to use a 2:1 belt drive, with the same ultra-fast 12-bit HS-7940TH servos I'm using on my direct-drive GoPro mount.

-- Gary

The gains set the amount of travel at the extreme end points of motion in either axis, the proper way to set them is to use a level sitting on the center of the platform, I have a small circular bubble level I use. First thing I do is make sure both axis are as close to the centerpoint of the servos travel as possible, sometimes it requires using a servo tester and mechanical adjustment to get it right. The other thing I do with the AV130s is use the servo tester to find the exact centerpoint of both external pots for the servos, ideally you want mechanical center and pot center to be the same.

Once that's done what I do is power up the multi on a level surface and use the bubble level to make sure the platform is level in both axis at the centerpoint and that the software is correctly set for the center point. Next I prop up one side of the multi so the mount travels to almost the limit of travel in that direction, put the bubble level back at the center of the platform and see how far off level it is. Now adjust the gain in whichever direction is necessary to get the platform level at that point in it's travel and the repeat the procedure in the opposite direction of travel. Unless there is a mechanical issue which can be the case with linkage drives being uneven, the platform should also be perfectly level at the end of its travel in opposite direction and the center point set earlier should still be the center point. Some not so great flight controllers I've used have caused the center point to drift once the gains were set so its worth checking again.

Now I repeat the procedure for the tilt axis and then check everything again afterward, the end result is the video you see me post. The gain settings are NOT for setting the speed of movement for the platform although some people use them for that but its a sure way to wind up with wobbly looking video because the level will be off to some degree once the platform moves off center depending on how far it moves. So the bottom line is that the gain settings are going to be different for every mount regardless of direct, gear or belt drive and the only way to set it properly is to use a level on both axis. Sometimes a change of as little as 1 or 2 can make a significant difference in how far off the mount is at the end of travel on that axis, really depends a lot on the flight controller and how they handle gimbal setup in the firmware.

Ken

 

[BorisS]

Ken when you find the gains in order for the gimbal to be level at its end points in tilt and roll, do you consider your actual flight mode or flying style, Expo etc. I am just noticing that a lot of time the AV 130 will be level at the end point but not on its ways there. Than I have noticed that my endpoint are much to extreme considering that i slowly hover and control the bird with dual 70% expo 40%. So actually i think i was doing it wrong and i should use end points to setup the gains that are not extreme but are slightly more than needed in the actual flight. Hope i am being clear what i mean.

Boris

 

[RTRyder]

Ken when you find the gains in order for the gimbal to be level at its end points in tilt and roll, do you consider your actual flight mode or flying style, Expo etc. I am just noticing that a lot of time the AV 130 will be level at the end point but not on its ways there. Than I have noticed that my endpoint are much to extreme considering that i slowly hover and control the bird with dual 70% expo 40%. So actually i think i was doing it wrong and i should use end points to setup the gains that are not extreme but are slightly more than needed in the actual flight. Hope i am being clear what i mean.

Boris

The short answer is no, flying style has no bearing on how the gains are set, they are simply an adjustment to make the platform level across its travel as best as possible. Servos, linkages, and drive ratios are what actually determine the speed that things move at along with the firmware and flight controller output circuitry although some are better than others at telling the servo what to do. You can limit the total amount of movement in either axis by setting the travel limits in the software, sometimes I do, sometimes I don't, depends on the mount and what its hanging under.

To illustrate the point I'm trying to make, watch from 3:25 onward in this video, this is not smooth or gentle flying yet its easy to see the camera platform stays flat and level in relation to the frame even at extreme banking angles. It's a Coptersky 2 axis GoPro mount, direct drive, and not exactly state of the art in camera mounts but with some TLC on the assembly of the mount and a careful setup as I described above, this is the end result so the process definitely works...

In this case it took a couple very high speed, high resolution, Savox servos to give the mount the speed it needed to work correctly. I could not have done this just by tweaking the gain settigns so it moved faster, it was a mechanical solution backed up by proper setup in the software.

Ken

 

[GGoodrum]

Actually, I never meant to imply that I thought the gains adjusted the speed of the outputs. I agree, that what it really controls is how much angular movement the servo will be commanded to move, in response to a given angle that the platform moves. I basically have done the same sort of adjustment that you have, but maybe not as precise, with a bubble level, but I think I'm getting close to the same results. I also did the mechanical zeroing of the servos, using the servo programmer.

Anyway ,none of this really changes my plan to try a 2:1 belt drive in each axis, with ultra-fast 12-bit servos. I still believe that mounts with lots of reduction are going to lag, in the response. This forces you to have to fly smoother, with small angular movements. Just my theory, but well see.

-- Gary

 

[Tabb Firchau]

Gary, keep in mind that on these mounts with lots of reduction still have the pots on the actual axis of rotation. As long as the servo's top speed (accounting for the reduction) is faster then the rate of disturbance it should compensate just fine assuming decent IMU. If a mount with 5:1 reduction can slew at 60 degrees per second max speed then it should still be plenty fast to deal with the disturbances we see on these smooth flying multis.

Tabb

 

[GGoodrum]

Gary, keep in mind that on these mounts with lots of reduction still have the pots on the actual axis of rotation. As long as the servo's top speed (accounting for the reduction) is faster then the rate of disturbance it should compensate just fine assuming decent IMU. If a mount with 5:1 reduction can slew at 60 degrees per second max speed then it should still be plenty fast to deal with the disturbances we see on these smooth flying multis.

Tabb

Yes, I can see how that could make a difference, having the external pots. I haven't played with these mounts enough yet to really do much more than theorize, I'm afraid. That will change soon, however, because I hope to have my own CS 6 flying by the weekend.

-- Gary

 

[DennyR]

Gary, keep in mind that on these mounts with lots of reduction still have the pots on the actual axis of rotation. As long as the servo's top speed (accounting for the reduction) is faster then the rate of disturbance it should compensate just fine assuming decent IMU. If a mount with 5:1 reduction can slew at 60 degrees per second max speed then it should still be plenty fast to deal with the disturbances we see on these smooth flying multis.

Tabb

As the gyro is 300 deg/sec the slew rate of the camera platform is somewhat of a mismatch. A 67 deg./sec gyro is what you need. If you want to get any advantage from a geared drive system.

 

[ssjheli]

I have one qustion, as a helicopter pilot dont understand why not mount the gyro on the element that has to be stabilized in heading lock mode? The gyro has a internal calkutated heading and gives output to the servo untill the gyro arrives are at the calkulated heading.
søren.