Hmmm many valid points. My usage case with a gasser would simply be maintain X headspeed. Stick to a fixed rpm on the rotor head and do not exceed a setpoint of engine rpm.
Would idleups be necessary on an AP equipped rig? At the moment the 5 point curve works well but if I could simply say “hey heli please maintain 1100 RPM headspeed yet don’t over rev past 15000rpm on the engine” it would be a thing of beauty plus one less bit of electronics to mount.
My personal opinion is, no. Idleups come from the 3D aerobatic world where a pilot sets a tame headspeed for takeoff/landing, then flips it into Wild Mode for flight. They are not used in full-size helicopters, running a combustion piston engine at anything other than the range between peak torque and peak hp results in poor fuel economy, and it results in poor performance from the governor. If you operate the engine too close to the knee of the torque curve, it will have no torque rise for the governor to use. If you operate it past the peak hp rpm the engine will experience huge droop on loading that the governor cannot respond to.
When you take into account the characteristics of the engines used in UAV heli’s, plus the gear ratio, this leaves only about 50 rpm main rotor range from optimum where the helicopter will actually perform decent. They are no different than full-size ones in that respect.
However, other folks consider the idleup feature to be something necessary to have. So my opinion is that it is fairly easy to code, you have to expect less than optimum performance if you use it, experienced pilots will not use it.
This does not preclude having a governor trim on a knob or slider like some full-size governors use, such as on the Rolls-Allison 250 turboshaft in the 206 Jet Ranger. That governor is a mechanical unit and it has a trim on the collective lever that the pilot can nudge to get the RRPM needle in the middle of the green to compensate for density altitude. So that is my current idea, maybe allowing a wider range of set speeds for pilots that want to use it. However, the one in the Jet Ranger only allows setting the headspeed from 394 +/- 5 rpm. A change of only about 1% either way.
Hi Chris
I really appreciate it.
Finally, I succeeded in getting rpm !!
I still do not know exactly what the problem is,
I’ve definitely confirmed RPM information from MP in my eyes.
Thank you very much, Chris.
Glad you got it working!