I tried Autotune starting at level 5. The level 5 tune was not agressive enough for me, so I progressed to level 8, hoping to see sequentially more aggressive tunes. To my surprise, the PID stayed about the same. It has been reported elsewhere that each Autotune session will adjust the PIDs again. As I stated, that was not my experience.
Could Tridge or one of the developers chime in as to how to get a “fresh” Autotune at a more aggressive level?
Thanks!
Same here, to mild.
BTW, when manually change P value on pitch to 1.50, the servo will end up move strangely, short movement (not following transmitter or FBWA stabilizing) and stuck on down position.
[color=#00BF00]Split off from release topic, so it does not get lost inside the release thread.[/color]
It’s hard to say whats happening unless we can get logs.
The tune level primarily changes the time constant, rate limit and the multiplier from P gain to D and I gain. The P gain may not change much.
Make sure your radio is calibrated so that you can demand the full pitch angle and roll angle.
Also you need to be very aggressive on the sticks, so that they spend as much time at the extremities and minimum time moving across. Because it tunes based on achieved rate (not angle) you don’t need to wait for it to achieve the angle before reversing the stick direction, so a second at each extreme before switching direction is enough.
[quote=“priseborough”]It’s hard to say whats happening unless we can get logs.
The tune level primarily changes the time constant, rate limit and the multiplier from P gain to D and I gain. The P gain may not change much.
Make sure your radio is calibrated so that you can demand the full pitch angle and roll angle.
Also you need to be very aggressive on the sticks, so that they spend as much time at the extremities and minimum time moving across. Because it tunes based on achieved rate (not angle) you don’t need to wait for it to achieve the angle before reversing the stick direction, so a second at each extreme before switching direction is enough.[/quote]
Thanks for getting back to me. I didn’t post tlogs cuz I thought it was more of a general question. That said, the PID changed ever so marginally from level 5 to 8. I mean maybe 5% max. I saw no change at all in the time constant from any of the tunes. In other words, I had it originally set to 22 and it stayed there. Based on the tuning guide, I then changed it manually to 18.
Yes, I was moving those sticks back and forth, full throw, as fast as I could. Yes, I read it was rate based and only held the sticks at extremes for a second.
Yes, even though my radio was already calibrated, I did it again to be sure.
So, back to my general questions; Is the difference between Level 5 and 8, in terms of aggressiveness, predominantly in the P and time constant.? If I set the I and D to 0, P to say, .6 and the Time Constant to 25 and start again are these good starting points for a Bixler? And if I do these settings and start over several times, what repeatability should I expect to get? If I keep on flying in Autotune after the 20 extreme control movements will that affect the tune? Or should I switch to manual or auto and not use Autotune? Is there any chance the Autotune could “over tune” the D parameter or Time Constant and cause oscillation?
Thank you for your help.
In answer to your questions:
Auto tune level adjusts time constant and the ratio of D and I gain to P gain. The P gain is what is adjusted during the tuning process and then the D and I are scaled from P depending on auto tune level. This means manually setting initial values for D and I will have no effect on the auto tune result.
In auto tune you should either be very aggressive on the sticks or not moving them at all. Avoid partial movements. Do not leave it in auto tune mode and switch to another mode as soon as you have finished the tuning.
I saw repeatability of around 10% when I used it.
Yes, if you set the auto tune level too high for the airframe, it can become unstable. So be ready to switch to manual if you are pushing the auto tune level higher.
http://www.youtube.com/watch?v=Dxz6_0_gP1w
Too busy making aggressive turn. I don’t realize I flew to low.