Hi,
I have my heli tuned well in stabalilze mode now. Remember, I am running a flybarred helicopter using H1 and the Flybarless setting. I am happy with both pitch and roll rate P=.05 I=.25 D=0 IMAX=500 and FF=.04. The heli feels like a plane with dihedral, when I roll it and let go, it rolls back. it seems very tollerant of high P values, when it wobbles it is not violent.
In a prevous post, sombody mentioned that he had broke landing gear when he switched to Alt_hold or Loiter can’t remember which one. I can reproduce his condition. He also mentioned 10 seconds before loiter or Alt_hold would work.
My normal response on the bench (Heli armed) and the mode changed to Loiter ro Alt-Hold was the swash would drive down to almost full negative pitch. The only difference was Alt_Hold I had cyclic and Loiter I had nothing. So with this resopnse, I was sure if I changed modes, it would end poorly.
So, tonight, I finished my rate tuning, getting dark, so I landed pulled full negative to burn off the rotor speed and switched the Heli in Loiter. I notice somthing different, I had a little cyclic. So I moved the collective to full positive, and the swash traveled slowly to full positive. Now we are getting some where. I tried switching to alt_hold and the same thing, I could move the swash up and down at a slow rate.
Humm, why did it do that.
So, I disarmed and re-armed the Heli, and it was back to its old thing, Loiter and Alt_hold drive the swash full negative. I switched back to stabalize and spooled it up and hovered it for 60 seconds or so, landed, shut down the motor, and loiter and ALT_hold functioned correctly again. This is a scary situation, loiter or ALT_hold is engaged, too early, it will screw itself into the ground.
Is this a leftover from the quad code, I take off on my IrIs most of the time in loiter. Right or wrong, I arm the IrIs, switch into loiter and hit the throttle, it takes some time after the “ARM” before the throttle will respond. (I make sure it has a GPS lock before I arm). The difference is the quad spins the motors on the ARM, the Heli does not.
Is the Pixhawk looking for a PWM signal on the throttle before it enables the “smart modes”
making more progress, I will try alt_hold and Loiter tomorrow after I fly it for a bit.
BV