Altitude Hold not working

Wanted to do a quick test of Gimbal so flew my Iris+ up and switched to ALT HOLD, after I while it appeard it was getting higher. Suddenly it went full speed to above where I was and figured it went to RTL. I thought it was odd because I had only been flying for 5 minutes. I pulled the logs and I found that in ALT_HOLD my Iris+ kept ascending to Geofence and then RTL’d. What would cause this?

[attachment=0]Screen Shot 2014-12-13 at 6.57.01 PM.png[/attachment]

This looks to be self inflicted. The Throttle In was above 1500 so the copter is going to rise.

Your dead zone is only 50 PWM so from 1550 up is climb which is where you had it. Mine is set to 100.

During most of the flight you were at almost 1700. Just over mid throttle.



I was thinking AltHold would hold altitude regardless of stick. Good to know.

Much good reading to be had.


If the throttle stick is in the middle (40% ~ 60%) the vehicle will maintain the current altitude. Outside of the mid-throttle deadzone (i.e. below 40% or above 60%) the vehicle will descend or climb depending upon the deflection of the stick. When the stick is completely down the copter will descend at 2.5m/s and if at the very top it will climb by 2.5m/s. These speeds can be adjusted with the PILOT_VELZ_MAX parameter.

The size of the deadband can be adjusted with the THR_DZ parameter (AC3.2 and higher only). This params value should be between “0” and “400” with “0” meaning no deadband. “100” would produce a deadband 10% above and below mid throttle (i.e. deadband extends from 40% to 60% throttle stick position).