Flight Question spurious RCS activity

[Dennyc39]

Sometimes when flying the DG, I have RCS activity that I think is uncommanded. None of the autopilot buttons are in, but the craft begins to rotate at an accelerating rate. I can stop it with Kill Rotation or Prograde, but it sometimes acts as though it is fighting itself and uses RCS fuel continually. Turning the RCS Off does not help., and trim setting has no effect. (Maybe it's only aerodynamic trim?)

This evening when trying to re-enter earth atmosphere, I could not control attitude, and the RCS would not respond. The ending was bad. Seemed like RCS fuel exhaustion.

 

[Zatnikitelman]

Were you under time acceleration when this was going on?
Do you have a joystick plugged in?

 

[Dennyc39]

I had time acceleration off and on; mostly off when trying to troubleshoot this.

I have a joystick plugged in (CH Pro), and both trim wheels were in their centered detents.

 

[Moach]

try flying without the stick (keyboards only) and see if you still experience problems...

sometimes, the "dead zone" in the action-center of the stick isn't large enough to prevent potentiometer spikes (and unwanted RCS blasts)
this happens with "dirty" potentiometers quite a lot... do you have that joystick for a long time?

a quick fix for that would be, whenever you're not controlling the craft by hand, switch off the RCS authority (hit ctrl+/ on the numpad)
but then, if you don't want that hassle, i'd advise you check if there's anyways you can add a bit of deadzone to that controller


or... see if you have any MFD's that you use which may be causing this.... there are some attitude controller MFDs that can retain command activity even if they're switched out of the screen (select something else)

a couple of aother non-MFD addons also have the ability to tamper with RCS - so check your addons :thumbup:

 

[n122vu]

I'd double-check the calibration on the Ch Pro. I've seen some joysticks that would have random noise in the cable or the connection that caused errant input to be registered.

Just as a troubleshooting question, is this a USB joystick or gameport?

**Edit**

:ninja: 'd!

 

[Dennyc39]

It's USB.

---------- Post added at 04:29 PM ---------- Previous post was at 04:23 PM ----------

The stick has many hours on it with X-Plane, though it always seemed smooth enough and quiet with that app.

I did shrink the dead zone to 200 with Orbiter, seeking better control in docking maneuvers.

I can proceed on suspicion that the stick is the source of the problem and leave it disconnected for orbit and transfer maneuvers.

 

[Tommy]

Increase the deadzone on the stick. A very slight "input" from the stick can easily go unnoticed in X-plane, since it's effect will be so small it will be "dampened out" by aerodynamic forces.

With Orbiter, ANY "input" from the stick will have an effect once you are in orbit, even the tiniest bit of RCS thrust will cause a rotation - and there's nothing to counteract the effects of that thrust.

 

[Izack]

Do you have any scripts running, or MFDs active that can control your attitude?

 

[Slaintemaith]

At least we know it's not a Gemini 8 recreation.

 

[coffeene]

This might help a little. For some reason I noticed my PeA would drop for no apparent reason. I have the Arrow in LEO Ecc 0.0000, switch to XR2, launch with good inc, achieve orbit. Then notice the arrow is Ecc 0.0009.

Upon further examination I noticed when I switched to outside view then back to inside view ALL ships had Ecc changes, including the ISS, that later de-orbited into the Atlantic.

I popped in here to announce my findings and post my addons and read this post. Deciding to try to unplug my joystick as well and noticed no Ecc changes.

If requested I'll post my addons but I think joysticks are the culprit as it did fix my problems.