[1.12.x] Anatid Robotics / MuMech - MechJeb - Autopilot - [2.14.3] [4th March 2023]

[OldMold]

I'm seeing weird behavior on ascent guidance with some rockets where MechJeb will just put the ship into a corkscrew roll. Not sure what is contributing to this, adding/removing reaction wheels and fins seems to only marginally help - can someone point me in the right direction to troubleshoot what controls may be at play?

I'm on the last dev version for 1.3.1. but I recall having similar issues with past versions, but never got to an answer.

Cheers!

 

[Jim DiGriz]

If it's just corkscrewing then it's probably a design problem where either you've got too much aerodynamic torque causing it to roll and/or you don't have enough torque from engines or reaction wheels.

If you can manually use the controls to neutralize the roll then it might be MJs fault.

If it's oscillating around the roll axis its probably MJs PIDs fault, and tuning the attitude controller could fix it.

If the displays in the lower left show that MJ is pinning the roll control at the rails trying to fight the roll but its still rolling then its pretty much certain its a design flaw.

Can you launch the rocket without MJ and not have it roll or does it spin under manual control as well?

etc..

 

[Gordon Dry]

I'm trying to use the Powered Explicit Guidance RSS/RO but what ever I do the engine never spools up...

I'm new to PEG but that it just does not want to work from the very beginning frustrates me.
In threads and wikis ppl say "the vessel will start to pitch very soon" but I don't see this in my case, like a dream that never fulfills...

It's MJ 2.7 for KSP 1.3.1, the normal rls version.

Edit:

It works with this version:
https://github.com/lamont-granquist/MechJeb2/releases/tag/mchenry14-131

Spoiler

 

 

Edited April 11, 2018 by Gordon Dry

[OldMold]

6 hours ago, Jim DiGriz said:

If it's just corkscrewing then it's probably a design problem where either you've got too much aerodynamic torque causing it to roll and/or you don't have enough torque from engines or reaction wheels.

If you can manually use the controls to neutralize the roll then it might be MJs fault.

If it's oscillating around the roll axis its probably MJs PIDs fault, and tuning the attitude controller could fix it.

If the displays in the lower left show that MJ is pinning the roll control at the rails trying to fight the roll but its still rolling then its pretty much certain its a design flaw.

Can you launch the rocket without MJ and not have it roll or does it spin under manual control as well?

etc..

 

I can launch them manually with a pretty great gravity turn consistently. MJ starts the spin gradually oscillating, rocking side to side like it's over correcting, and it just exacerbates from there until it's just corkscrewing and barely tilting over into the g-turn. 

[Gordon Dry]

@OldMold

I guess the attitude settings worked better in earlier versions - let alone the fact that in earlier versions my latest settings have been stored, now they're always back to default no matter if I revert or had a successful mission.

This is for latest official rls for KSP 1.3.1 and KSP 1.4.2 and also the myhenry rls that I use now in RO/RSS.

I think it was over a year ago, so to KSP 1.2.2 times, that the attitude settings were stored and it also worked better fighting the wobble and roll.

[OldMold]

Welp that fixed it! Thanks for pointing me to the attitude settings. Switching from MJ controller to Hybrid model worked like a charm, and the setting sticks!

[El Sancho]

5 hours ago, OldMold said:

Welp that fixed it! Thanks for pointing me to the attitude settings. Switching from MJ controller to Hybrid model worked like a charm, and the setting sticks!

@OldMold

Sorry but I've been following this, and I'm totally confused by your reply. WHAT fixed it? And what's with that github site?

[Gilph]

I have to say that the hybrid controller for liftoff of Kerbin is much more stable for the ugly stuff I'm trying to get into orbit. It's much smoother in the first 25K and I have way less flips.

[viperwolf]

What causes your craft to hover instead of landing?

[OldMold]

20 hours ago, El Sancho said:

@OldMold

Sorry but I've been following this, and I'm totally confused by your reply. WHAT fixed it? And what's with that github site?

So my problem was that the rockets would start to "corkscrew" roll on ascent. @Gordon Dry helpfully pointed out that this is likely due to the PID settings in the attitude controller.

The PID (proportional–integral–derivative) controller settings are tunable, but require a level of calculus that exceeds my grasp (and my patience of trial and error fiddling), so I switched to a different default controller that MechJeb supports. You can find it through the "Attitude Adjustment" section of MechJeb, and switching it from the default "MJAttitudeController" to "HybridController". This worked for me beautifully, but of course your mileage may vary depending on your craft designs and/or mods that you have installed. Pic below:

Hope this helps!

[Gordon Dry]

@OldMold When PID settings worked for a (not tiny and light) launcher, then they were:

Tf range: min. default 0.1 (or 0.01) - max. 0.15
Kd = 1.5
Kp = 30
Ki = 60

Also no roll and steering control in Ascent Guidance.

But the HybridController helps a lot.

Edited April 13, 2018 by Gordon Dry

[El Sancho]

Hybrid controller does help a lot in Ascent Guidance, but I think MJ Controller works better when maneuvering in space.

[Gordon Dry]

@sarbian

Using dev #798

After going EVA and boarding, the MJ icon disappeared from toolbar, incl. the list of available icons.

The only MJ-related exception in my log is:

NullReferenceException: Object reference not set to an instance of an object
  at MuMech.RCSSolverThread.GetThrottles (.Vessel vessel, MuMech.VesselState state, Vector3 direction, System.Double[]& throttles, System.Collections.Generic.List`1& thrustersOut) [0x00000] in <filename unknown>:0
  at MuMech.MechJebModuleRCSBalancer.GetThrottles (Vector3 direction, System.Double[]& throttles, System.Collections.Generic.List`1& thrusters) [0x00000] in <filename unknown>:0
  at MuMech.VesselState.UpdateRCSThrustAndTorque (.Vessel vessel) [0x00000] in <filename unknown>:0
  at MuMech.VesselState.Update (.Vessel vessel) [0x00000] in <filename unknown>:0
  at MuMech.MechJebCore.FixedUpdate () [0x00000] in <filename unknown>:0
 
(Filename:  Line: -1)

Log:
https://www.dropbox.com/s/xk4am3tgeg4oami/2018-04-14_3 KSP.log.7z?dl=1

Edit:

@Gotmachine I have the suspicion that this could be triggered by MandatoryRCS.

Edited April 14, 2018 by Gordon Dry

[Gotmachine]

@Gordon Dry Why that ? I have some doubt about it since the only thing MandatoryRCS is messing with is the reaction wheels partmodule, it has not interaction with the RCS partmodules. Looks like to me that the MechJeb cache for RCS thrusters got corrupt somehow when switching vessels (technically EVA is a vessel), and judging by the "RCSSolverThread" class name, I would say that some common threading mess is happening in MechJeb.

[Gargamel]

Bug report:

If "Auto Deploy Solar Panels" in Utilities is already checked when loading a vessel on the launch pad, the panels will not deploy when reaching 70km, not using ascent guidance. Unchecking and rechecking the option works fine, deploying the panels. Loading a vessel on the LP, and then checking a previously unchecked ADSP in utilities works fine.

Panels were inside a fairing that deployed at 70km. Ascent guidance does not have this bug, previously checked ADSP works as intended. /O/

MJ 2.7.0 in KSP 1.3.1

Tracker: https://github.com/MuMech/MechJeb2/issues/1017

[Mark Kerbin]

@sarbian I noticed you recently added a decent aircraft autopilot. Thanks for that btw! No way was I going to fly halfway across kerbin for some BS without it.

While doing that I noticed the Autopilot is lacking something kinda sorta important, but not necessarily critical.

Drop Tank Functionality.

Auto stage apparently doesn't register if all the fuel in x stage is gone if its just fuel, and thus doesn't pitch it.  (My theory. No clue if its actually how it works.)

Any chance you could take some time out of your day to improve this? 

That thing is empty. Info keeps closing when I capture picture. Auto stage is on. 

[Gargamel]

2 minutes ago, Mark Kerbin said:

Auto stage apparently doesn't register if all the fuel in x stage is gone if its just fuel, and thus doesn't pitch it.  (My theory. No clue if its actually how it works.)

 

 

Auto stage has been working fine for me for years in planes.   Make sure your drop tanks are the fist (or next stage) to go, set your fuel flow (or use a mod) to make sure the drop tanks are emptying first, and then use Autostage.   Planes will draw from all tanks evenly if it's liquid fuel, so you really have to drain those tanks before the others. 

[Mark Kerbin]

16 minutes ago, Gargamel said:

Auto stage has been working fine for me for years in planes.   Make sure your drop tanks are the fist (or next stage) to go, set your fuel flow (or use a mod) to make sure the drop tanks are emptying first, and then use Autostage.   Planes will draw from all tanks evenly if it's liquid fuel, so you really have to drain those tanks before the others. 

Ill have a look. Ive got the fuel drain set up, but the stage ill have a look at. Would the auto stage not like have the engines on the first stage?

Edited April 15, 2018 by Mark Kerbin

[Mark Kerbin]

@sarbian + @Gargamel Annnnndddd now it works... I clearly had a kraken attack. Thanks for your help.

Edited April 15, 2018 by Mark Kerbin

[mcbmaestro]

Can someone please help me with this.. I can't get any help with this and it's driving me insane.

I want to make all of MJ available at the start of career.  Now I know how to do this, done it many times:  change the unlock levels to start in the config file.

It's all working fine, I get it all at start of career EXCEPT Landing guidance.  I have checked that I did it wrong in the part file, I even copied over a fresh MJ and edited it again.   Same thing.  Everything but landing.

I suppose doing landers manually isn't the end of the world,  but can anyone please tell me what I'm doing wrong?

So I noticed in my career when I have every tech unlocked, I do get the Landing Guidance.  So it seems for some reason the landing guidance is still not working at the 'start' tech and still only working at some tech later on.

Edited April 15, 2018 by mcbmaestro

[Beetlecat]

On 4/14/2018 at 5:41 PM, Mark Kerbin said:

@sarbian + @Gargamel Annnnndddd now it works... I clearly had a kraken attack. Thanks for your help.

I like the looks of that plane -- any more shots/kerbalx dl?

[Mark Kerbin]

15 hours ago, Beetlecat said:

I like the looks of that plane -- any more shots/kerbalx dl?

Ill check if I have that version of the plane, drop tanks had to be edited a bit to extend range.

[Gordon Dry]

@sarbian I didn't have this for some time, but here it is again (using #799):

NullReferenceException: Object reference not set to an instance of an object
  at MuMech.RCSSolverThread.GetThrottles (.Vessel vessel, MuMech.VesselState state, Vector3 direction, System.Double[]& throttles, System.Collections.Generic.List`1& thrustersOut) [0x00000] in <filename unknown>:0 
  at MuMech.MechJebModuleRCSBalancer.GetThrottles (Vector3 direction, System.Double[]& throttles, System.Collections.Generic.List`1& thrusters) [0x00000] in <filename unknown>:0 
  at MuMech.VesselState.UpdateRCSThrustAndTorque (.Vessel vessel) [0x00000] in <filename unknown>:0 
  at MuMech.VesselState.Update (.Vessel vessel) [0x00000] in <filename unknown>:0 
  at MuMech.MechJebCore.FixedUpdate () [0x00000] in <filename unknown>:0 
 
(Filename:  Line: -1)

RCS does not work at all because of this.

I switched to a polar satellite / scanner vessel that already was in orbit for 130 kerbal days to change inclination.

Rotating to a maneuver node had to be worked out without RCS, but as soon as the node was reached RCS started to fire, all thrusters the same time and without stopping - I had to disable RCS to stop wasting MP.

Log:
https://www.dropbox.com/s/2pzfu08y3r471ih/2018-04-22_1 KSP.log.7z?dl=1

Edit: Gonna remove Fusebox (issues) and WernherChecker (issues with KCT) and see again... @linuxgurugamer

Edited April 22, 2018 by Gordon Dry

[Swagger897]

 

Just got finished with the 1.4.2 update and updated through CKAN. CKAN states current version is only 1.4 but I'm interested to see what others here are getting if they're on current version too. Once I get to the main screen and open my save I'm getting an #autolocXXXXXX error and game will CTD.

[Mittrandir]

Hi, I'm not aware if this is possible (I'm a newbie in moding KSP!), but it would be nice if one was able to specify the coordinates of any custom runway (as the ones in RO/RSS) to the aircraft approach and Autoland feature, directly via drop menus in MechJeb.