Autopilot Settings

[jte65]

Question about the autopilot for those who have it installed. Are settings for sensitivity, torque, rates of climb/descent and turn programmed by Van's locked files or are they just set at the Dynon defaults? If they are the Dynon defaults, what settings have those with autopilots ended up using? We tried the autopilot this weekend and while it works, it does seem to wallow in turns. Once it gets to an assigned heading, it generally keeps it but is not very stable. We still have a heavy right wing and thought that perhaps this was confusing it at times. A lot of twitching of the stick which we have not noted with other AP brands- perhaps this is normal with the Dynon?

Jeff

 

[Mark Henderson]

I just started testing mine. I have the same twitching in the stick, but roll is fine. I have not adjusted mine yet. I spoke to another 12 owner who advised that the Dynon controlls the settings, not the locked Vans file. There is no point in adjusting anything until the 5.4 firmware has been installed. I hope to do that today. The autopilot needs to be adjusted to be less sensitive.

 

[jte65]

Thanks Mark. I already have 5.4 installed. Will be interested in hearing what you and others find in terms of optimal settings. You comment about the sensitivity being too high makes sense. I thought 5.4 was supposed to minimize the twitching of the controls. However, we did the upgrade to 5.4 prior to the first flight so I can't make a comparison to what it was like with prior firmware versions.

Jeff

 

[Brantel]

The ride is what is important, not the twitching of the stick....twitching on the ground is absolutely normal. In the air it is the ride that counts and the ride can be tuned...

The AP must be tuned, the numbers from Dynon are just a starting place.

I recommend you set the Turn Rate Limit parameter to "0" to enable the latest mode for the roll servo.

Use the following for a guide on how to tune the advanced pitch parameters. Start at the top and work your way down if needed....these defaults are Dynon's defaults and if Van's has modified them for the 12, disregard them.

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Pitch Gain: Use only after sensitivity is set as well as it can be. Increase gradually if airplane does not settle on altitude. The default setting is 20. ​

Altitude Gain (ALT GAIN): Use only after sensitivity and all of the above settings are set as well as they can be. Increase gradually if airplane levels off too soon. Reduce gradually if airplane overshoots altitudes after climbs and descents. The default setting is 6.

Pull Rate: Use only after sensitivity and all of the above settings are set as well as they can be. Controls the rate the AP will push or pull when changing vertical speed. The default setting is 10.

VSI Gain: Use only after sensitivity and all of the above settings are set as well as they can be. Increase gradually if overshooting altitude after climbs or descents, decrease if rounding out too early. The default setting is 15.

G Error Gain (G ERR GAIN): Use only after sensitivity and all of the above settings are set as well as they can be. Increase gradually if vertical speed changes are not smoothed enough; Decrease if ride is too harsh. G Error Gain adjustments affect the most noticeable changes while the aircraft is in turbulence. The default setting is 10.

G Error Limit (G ERR LIM): Use only after sensitivity and all of the above settings are set as well as they can be. Controls the max additional G the autopilot will push or pull to control vertical speed (up to the G limiter). G Error Limit adjustments affect the most noticeable changes while the aircraft is in turbulence. The default setting is 25.
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[jte65]

thanks Brantel for taking time to outline your suggestions for settings!

Jeff