Auto Tune on Skyviper GPS

ArduCopter SkyViper
1

I had tried auto tune today was in a large indoor space ,so I no wind influence . Armed in Althold , haven’t flown indoors very much with this one . Has a lot of drift. then used mode button combo to switch to Auto tune. Not sure if it was correct but here is what I got for mugs on the Web auto pilot interface.
SkyViper
SystemIMUBaroGPSEKFTransmitterCameraMotorsMessages
Flight Controller Messages

13:40:23 Initialising APM
13:40:27 Initialising APM
13:40:32 Initialising APM
13:40:38 Initialising APM
13:40:42 Initialising APM
13:40:47 Initialising APM
13:40:47 Tmode: thr mid 497
13:40:48 EKF2 IMU0 initial yaw alignment complete
13:40:49 GPS 1: detected as u-blox at 115200 baud
13:40:50 EKF2 IMU0 tilt alignment complete
13:40:54 MGA: ack:54 nack:0
13:41:01 u-blox 1 HW: 00080000 SW: ROM CORE 3.01 (107888)
13:41:02 PreArm: Gyros not calibrated
13:41:12 GPS: u-blox 1 saving config
13:41:56 Initialising APM
13:42:01 Initialising APM
13:42:06 Initialising APM
13:42:10 EKF2 IMU0 initial yaw alignment complete
13:42:11 GPS 1: detected as u-blox at 115200 baud
13:42:12 EKF2 IMU0 tilt alignment complete
13:42:15 MGA: ack:54 nack:0
13:42:23 u-blox 1 HW: 00080000 SW: ROM CORE 3.01 (107888)
13:42:24 Tmode: action 19
13:42:24 Tmode: mode ALT_HOLD
13:42:31 EKF2 IMU0 in-flight yaw alignment complete
13:43:04 AutoTune: Twitch
13:43:05 AutoTune: success 0/4
13:43:07 AutoTune: success 0/4
13:43:09 AutoTune: success 0/4
13:43:09 AutoTune: Twitch
13:43:11 AutoTune: success 0/4
13:43:11 AutoTune: Twitch
13:43:12 AutoTune: Twitch
13:43:13 AutoTune: Twitch
13:43:14 AutoTune: Twitch
13:43:15 AutoTune: success 1/4
13:43:15 AutoTune: Twitch
13:43:17 AutoTune: Twitch
13:43:17 AutoTune: success 1/4
13:43:18 AutoTune: Twitch
13:43:19 AutoTune: success 1/4
13:43:20 AutoTune: Twitch
13:43:21 AutoTune: success 1/4
13:43:23 AutoTune: success 1/4
13:43:25 AutoTune: Twitch
13:43:25 AutoTune: success 1/4
13:43:26 AutoTune: Twitch
13:43:26 AutoTune: Twitch
13:43:28 AutoTune: success 1/4
13:43:32 AutoTune: Twitch
13:43:33 AutoTune: Twitch

The instructions in Arducopter wiki are confusing to me mainly because we don’t have any mutilation switch .

2

Why would you perform an Auto Tune on a Skyviper GPS? I have many Arducopter craft where Auto Tune is useful but that’s not one of them. Defaults seem to just work.

3

I was hoping to tame the drift it has in Althold , as the SV has no trim on tx . I thought it might be helpful . But like your reply it wasn’t ,

4

Drift which way in AltHold? Even with Transmitters that have trim you would not use them for a multirotor running Arducopter. Always centered trim and address the issue you are having with configuration, calibration or tuning.

5

Hi Joe,

I’ve run Auto Tune on the frames many times, but nothing ever really achieved a better tune than what Leonard was able to provide us.

FYI, what you are seeing (message-wise) is in-line with what to expect.

If you aren’t doing it already, I would only run Auto Tune in a Per Axis mode, as the 1200 battery won’t be able to complete a full tune before running out. We were doing Roll for a battery, then Pitch for a battery, then Yaw.

1 Like
6

Thanks Matt , I think I understand what was confusing , this is a long process then . And I had one of 4 axis complete . And dk yes the Skyviper flies very well right out of the box . Which is a very good thing for old newbie like me who knows nothing about these things .

7

the drift in althold is normal, as only the altitude is corrected, other axis are free. Use Loiter or Poshold, if you want no drift

1 Like
8

If you have fast drift in altitude hold (indoor) mode in the absence of wind, you might want to try calibrating the accelerometer.

https://support.skyrocketon.com/hc/en-us/articles/115013506488-Advanced-Calibration-Methods

http://ardupilot.org/copter/docs/common-accelerometer-calibration.html

If that doesn’t help, the frame may be distorted such that the props are not all level. It’s not easy to fix this on a cheap molded plastic frame…

1 Like
9

I will post a badly needed frame fix soon. Very easy. Also need perfectly balanced prop shafts, which I am now having to work on. I have had position hold drift down to <2’ radius in calm conditions with my formerly perfectly square framed, repropped craft. Trying different props and have found Autotune Mode to be very useful and functional. Upgrades rock. So quiet and calm, with improved efficency (flight time), acceleration, etc.Also give you the options needed to try different motors! GF 5550 bn3bl on Crazypony 0820 (w/resoldered leads) works very well. Serious upgrade. Reshim motor as needed, new 12 & 13t pinions on order. Where can we find new prop shafts? W/gears, i guess.