Alt_Hold and Loiter learnings

Hi again,

A few things I have learned after 30 flights or so:

Throttle Accel:
This appears to change how much automatic compensation occurs with a disturbance. If you move the heli up and down rapidly, you can see the swashplate doing the opposite of the movement. The higher the P and I value, the more the swash moves.

Throttle Rate:
This seems to change the band with of the total pitch amout available to the system. If I run a low P value .001, it limits the total travel on my machine to around 5 degrees in alt_hold or Loiter. so, if you are at 4 degrees when alt_hold is activated, The total amount of change that can occur is plus or minus 2.5 degrees pitch from that point. If I increase the number to .1, I can get almost full through of the collective on the bench when I move the collective stick up and down.

Altitude Hold:
As I increase this number, the swashplate followes my imputs on the collective stick faster. If I reduce the number, it will still react to the stick, but the maximum speed of the swashplate is reduced.

I have now reduced my heli from 12S lipo to 10S to get some of the power out of it. I dont need 7HP for this and it is complicating the tuning.

I am still not suscessful with Alt_hold or loiter. It acts like the it is acting opposite to the barometer. Now that I have slowed down and constrained the control loops on the throttle and collective, it seems to increase altitude at a increasing rate when alt_hold or Loiter is activated.

I need some help here, sombody have any ideas what is going on here??

I attached my log file of the last flight.


Hi Bobby,

I am stil struggling to achieve flight at alt_hold. I looked over your settings above. Do you advise me to use them? is that also work for me?

Thanks, Have a nice day.

Great post. The only thing I have to say is that when I first started with my trad heli, 450, APM 2.6, I had severe problems with alt hold. The altitude seemed to be reverse of the baro. Rob L. suggested that it was due to vibration. I added much better dampening and it solved my problems.