Powerplant - N1 Changes Unnatural During Cruise/Descent

[amahran 603]

While descending or during cruise, making minor changes to the throttle results in unnatural changes to the engine N1:

1. The N1 could snap from one number (e.g., 66.0%) to another (e.g., 65.2%) within something like a quarter of a second. This is just not natural for a turbine to do, especially considering how long N1 changes typically take (for a first order system, the time to move 50% of the way from one state to another should be the same no matter the size of the input...in a simple scenario, such as comparing 60%-61% to 60%-65%).
2. N1 logic could be reversed in descent at times: in some instances you could have an N1 (e.g., 66%) and try to reduce it a touch by lowering the thrust levers a bit...and it goes a bit higher instead (e.g., 66.2%), once again, very unnaturally snapping.
3. In some instances, moving the throttle back from the climb detent to the manual range results in a small increase in N1 before the decrease to cruise power.

 

I know this topic here exists, but this is not relevant: I use a Microsoft Sidewinder Force Feedback 2.

[JRBarrett 675]

Hans has made improvements to the throttle position vs. N1 processing, and it is working well in the test version. This will be included in the first update.

[JRBarrett 675]

I would add that for anyone experiencing any sudden uncommanded thrust changes, it would be a good idea to look at the throttle axis in the Windows joystick calibration menu while moving the throttle from one end to the other.
 

Older controllers that use potentiometers to resolve position can be subject to noise spikes due to contamination by dust, or having a worn spot. These are most easily seen in the Windows calibration menu as a sudden “glitch” in displayed position. 

Newer controllers with Hall effect position sensors are normally not subject to this problem.

[amahran 603]

I see some general improvements in N1 change commands with the new update during climb and cruise adjustments. However, the descend phase N1 movements still needs improvement. 

 

Some steps to recreate it:

1. Get to cruise altitude of FL400
2. Begin a 2500 fpm descent
3. At various points, make minor thrust lever adjustments

You'll note that at some points the thrust lever commands simply do not correspond to logical N1 changes. I've seen N1 snapping (in one instance I think it was as bad as a 10% N1 snap), reverse sensing (decrease thrust lever position causes an increase in N1, or vice versa), and too rapid an N1 response to thrust lever positions. I can't recreate exactly what it is because it seems random in nature, yet consistent enough that it happens on every flight.

[Aerosoft Team [Inactive Account] 51558]

Yes as written, this is a area of concern for us as well and will be looked at again.