Jump to content

[PART, 1.0.2] Anatid Robotics / MuMech - MechJeb - Autopilot - Historical thread

r4m0n

By r4m0n
in KSP1 Mod Releases

 Share

Recommended Posts

billkerbinsky

billkerbinsky

Posted
Posted
Thanks!

That worked. I took 2/3 of the fuel out of the Tug and set it so the nuclear engines fired with the last stage. The TWR changed to 2 or greater on all the stages. Mech Jeb was able to handle it, easy. In fact it kept the last stage, which I drained of its fuel before decoupling, leaving me with a space Tug which had tanks that were almost full again. Funny how less fuel and/or engines seems to be the answer to my overbuilding. Hmmm...

So it was really too much fuel in the stage before the tug... you should be able to shrink that stage's tanks and leave the tug mostly fueled and make it to orbit.

I suspect that what you saw is a bug/unintended behavior (ascent guidance shouldn't be pointing the nose below the horizon during a burn!), but it may only surface when there's little to no chance of reaching orbit ...

Link to comment
Share on other sites
Ricardo79

Ricardo79

Posted
Posted (edited)
Okay, having a weird Mech Jeb problem, which seems to happen on and off and I forgot how to fix it. Last night was having issues getting a Fuel Trailer into space. This morning realized that it wasn't Mech Jeb but the design. Once it was corrected Mech Jeb was able to place two into orbit, one after the other, no problem.

Now, I also decided to see if I could place my new Zero-G Shuttle/Tug into space again. Did it once, by the skin of my teeth, with Mech Jeb, and wanted to see if I could do it again. It is a wonderful, and simple, design that seems very common among players but mine is as heavy as heck and even needs to use its own nuclear engines near the end to help get into orbit.

Tried. Failed. Tried. Failed. Most of the failures were engineering and design issues and I finally got one out of the atmosphere....but Mech Jeb not only continued to try to gravity turn but pointed at the planet. So I figured, okay, my design is the problem..let me look it over, add some more SAS, some duct tape, so on. Make it stable, give Mech Jeb more torque and so on. Maybe it is too sluggish or something? Maybe too much fuel in the craft?

Nothing seems to work and after a few hours of watching it get out of the atmosphere only to watch it dive right back in....I'm looking to see if this is just a try, try again problem, a reboot problem (turn off the game and turn it back on), or something else.

It sounds to me this is a desing failure.

(spacethugs mostly uses just monoprop and some of them uses the smallest LFO engines But they are in no way heavy.)

If it is an asteroid mover that's another story...

But still if MJ points to the heart of the planet that is a common maneuver called circularize.

Just look at the map (or the MJ's orbital info window) if you find your orbit is eccentric that's why MJ points your ships nose down.

(Also for heavier more bulky craft's try to adjusting the curve of the ascend start the gravity turn late 20-25k high and flatten it out higher even 450k despite what kind of a low orbit you wanna make).

In this way the fuel efficiency is not the best, but the stability is maxed out during ascend.

edited here:

As for the below horizon thing. If you circularize in the uppermost part of the atmosphere you can get away with poorly designed ship sometime by building up orbital velocity.

Where there isn't much air resistance you can build up speed for sure even below 1g TWR with a little descend or better levelled flight.

Just watch SSTO-s video in the youtube.

If you have a 55-60 Km circular "orbit" and can gain even the tiniest amount of speed your apoapse will rise over time, and you find yourself slipping out from the atmosphere.

Edited by Ricardo79
Link to comment
Share on other sites
helaeon

helaeon

Posted
Posted

I think I may have found something broken. It looks like it is in all mechjeb dev versions going back to the addition of the arrows. I get this error spammed in my log on a craft that has ever been part of a docking-undocking. But not the ones that never have been. Decoupled doesn't do it. Disconnecting fuel pipes via KAS does. All of the arrows are disabled in my Attitude Adjustment window. I toggled them on and off just to make sure. I completely unloaded mechjeb and reset everything to defaults re-loaded and re-saved with no mechjeb and error is still there. It does not seem to happen if the craft is re-united.


[Error]: MechJeb module MechJebModuleDebugArrows threw an exception in OnUpdate: System.NullReferenceException: Object reference not set to an instance of an object
  at MuMech.MechJebModuleDebugArrows.OnUpdate () [0x00000] in <filename unknown>:0 
  at MuMech.MechJebCore.Update () [0x00000] in <filename unknown>:0

That's spammed pretty heavily. Quicksaving and reloading after undocking doesn't cause it to stop. Weird thing in testing this on varioius vessels in order to narrow down precisely what I saw in common the first vessel I noticed it with stopped exhibiting the behavior and I don't know why.

Here is a fat output_log for you where I was switching between the various vessels trying to see which ones would throw the exception https://www.dropbox.com/s/ncyjz07iz03oxyl/output_log.txt?dl=0

Link to comment
Share on other sites
funk

funk

Posted
Posted
I think I may have found something broken. It looks like it is in all mechjeb dev versions going back to the addition of the arrows. I get this error spammed in my log on a craft that has ever been part of a docking-undocking. But not the ones that never have been. Decoupled doesn't do it. Disconnecting fuel pipes via KAS does. All of the arrows are disabled in my Attitude Adjustment window. I toggled them on and off just to make sure. I completely unloaded mechjeb and reset everything to defaults re-loaded and re-saved with no mechjeb and error is still there. It does not seem to happen if the craft is re-united.


[Error]: MechJeb module MechJebModuleDebugArrows threw an exception in OnUpdate: System.NullReferenceException: Object reference not set to an instance of an object
  at MuMech.MechJebModuleDebugArrows.OnUpdate () [0x00000] in <filename unknown>:0 
  at MuMech.MechJebCore.Update () [0x00000] in <filename unknown>:0

That's spammed pretty heavily. Quicksaving and reloading after undocking doesn't cause it to stop. Weird thing in testing this on varioius vessels in order to narrow down precisely what I saw in common the first vessel I noticed it with stopped exhibiting the behavior and I don't know why.

Here is a fat output_log for you where I was switching between the various vessels trying to see which ones would throw the exception https://www.dropbox.com/s/ncyjz07iz03oxyl/output_log.txt?dl=0

same here...

Link to comment
Share on other sites
smjjames

smjjames

Posted
Posted (edited)

Hm, does dev build 405 have the new landing code in it? Because the landing behavior is, well, different, however, I'm not sure whether it's because of my ship design, TAC fuel balancer, or both (doesn't seem to be TAC fuel balancer though). It just crashlanded this ship sideways at over 100 m/s (only two parts exploded on impact). I'm going to try a more standard lander before I make any real conclusions.

Mechjeb has landed a ship with a similar kind of configuration before, so I know it can land that kind of thing.

Edit: You know what, I think it's possible that the engines I used in the craft below simply aren't strong enough. I landed a more typical lander and it landed just fine.

screenshot33_zpspapn2v3x.png

Also, whenever I try to use non-stock thrusters that have a strength stronger than 1 (vernier thrusters too), it goes crazy with the visual effects with light shooting every freaking where and it seems to WAY overthrust with thrusters like that.

screenshot21_zpsdmtrmakr.png

Edited by smjjames
Link to comment
Share on other sites
Ricardo79

Ricardo79

Posted
Posted

While I was having memory issues and were close to the limit of the 32bit.

MJ was crazy sometimes. And yes made some interesting moment for me for example forgot to brake and crashed my ships sometimes. (good designed ones)

So maybe you have some memory issues too. just check if KSP is below 3gig RAM usage.

Right now with the 405 I am playing for 2 hours (building. So massive screen changes between VAB and launchpad) The memory eating seems to be gone. Thank you.

Link to comment
Share on other sites
sarbian

sarbian

Posted
Posted

The RCS balancer can get a little crazy and the vernier seems to distrub it even more. One of those days I'll try to understand how it works, but that won't be soon...

Link to comment
Share on other sites
billkerbinsky

billkerbinsky

Posted
Posted
No, I'm positive that it was the design. I tried it with a different (though FAR lighter) craft and it landed fine.

if there's a common thread, it's that mechjeb doesn't check to see if what you're asking it to do is actually possible before it starts trying to do it..

Link to comment
Share on other sites
smjjames

smjjames

Posted
Posted
if there's a common thread, it's that mechjeb doesn't check to see if what you're asking it to do is actually possible before it starts trying to do it..

True. I've found that my ship apparently has a thrust balance problem though, which messes things up, even though MechJeb is appropriately cancelling when the angle gets out of whack. Basically, it's all coming down to ship design here.

Link to comment
Share on other sites
Starwaster

Starwaster

Posted
Posted

Also, whenever I try to use non-stock thrusters that have a strength stronger than 1 (vernier thrusters too), it goes crazy with the visual effects with light shooting every freaking where and it seems to WAY overthrust with thrusters like that.

http://img.photobucket.com/albums/v214/smjjames/screenshot21_zpsdmtrmakr.png

Get RCSFX. It seems to be immune to that effect.

Link to comment
Share on other sites
Starwaster

Starwaster

Posted
Posted
I think I have it, or rather I have a folder called ModuleRCSFX. Not sure which mod I got it off of.

Real Fuels.

And and I just realized that you need a config to patch it for RCSFX. Raptors stock configs for RF is should have it. (If not now then next time he updates)

Link to comment
Share on other sites
helaeon

helaeon

Posted
Posted
So I connect 2 ship via KAS, disconnect them and I should get the error ? Should be easy to fix. Thanks

Yes, or dock and undock. It seems the "parent" ship is not affected only the child. In the case of my little Duna flier it was affected and the base was not. But that's also the ship that stopped exhibiting the error for the reason I couldn't figure out.

My space station around Minmus that I haven't used in a very long time was exhibiting the error, I did use the KAS fuel pipe on it once a very long time ago. My remote drills were also exhibiting the behavior and those were never connected via KAS just docking ports when I landed the stack of them. Though I did stick a RTG to them via KAS.

Thanks for looking into it.

Link to comment
Share on other sites
Valley

Valley

Posted
Posted

Any tutorial on how to use Mech Jeb's Rover Controls? I have figured out a few things by working with it on the ground at KSC - have it going the right direction for one - but can't figure out how to keep it under a certain speed. On the Mun it will end up just flipping or crashing. I also hear it is not very good with going down hill.

Link to comment
Share on other sites
damerell

damerell

Posted
Posted

I've got a bit of a problem with MechJeb. The "RCS balancer" window offers a "Smart translation" option. "Smart translation" doesn't seem to do anything useful, but instead makes RCS behave very oddly. However, if it's not turned on, all the other options vanish (there's an "if (balancer.smartTranslation)" in MechJebModuleRCSBalancerWindow.cs which hides them all), so there's no way to turn off RCS for rotation, which I'd like to both to save monoprop and because I'm, ahem, usually docking unbalanced vehicles and so RCS rotation also makes them translate. I would be utterly delighted if the answer to this question is "you missed an obvious tickybox, idiot".

Link to comment
Share on other sites
Ricardo79

Ricardo79

Posted
Posted
The RCS balancer can get a little crazy and the vernier seems to distrub it even more. One of those days I'll try to understand how it works, but that won't be soon...

I didn't tried that, But I see "positive" changes inside the windows. Minor ones, like a +- button on the node precision scale. That's neat.

I don't know if the mod don't allow it or I am just blind. But in the custom window editor I cannot see the execute next node button as a usable option.

I created one window with all the info I'd use but that one. Is it there somewhere?

There are buttons like open and close solarpanels. (I didn't see toggle though... :D ) But hey what is inside it changed a lot since I first saw it. And absolute into the more positive sfera.

Thank you.

P.S.: Yesterday was a run for a 6 hour gaming in one go. built up 25 craft and only 600 MB surplus memory usage (from start to finish) So I am absolute sure about that memory leak problem is gone.

Link to comment
Share on other sites
Starwaster

Starwaster

Posted
Posted (edited)
I've got a bit of a problem with MechJeb. The "RCS balancer" window offers a "Smart translation" option. "Smart translation" doesn't seem to do anything useful, but instead makes RCS behave very oddly. However, if it's not turned on, all the other options vanish (there's an "if (balancer.smartTranslation)" in MechJebModuleRCSBalancerWindow.cs which hides them all), so there's no way to turn off RCS for rotation, which I'd like to both to save monoprop and because I'm, ahem, usually docking unbalanced vehicles and so RCS rotation also makes them translate. I would be utterly delighted if the answer to this question is "you missed an obvious tickybox, idiot".

Yes, it's called Smart Translation. That's what turns on RCS Balancing. ;)

Edited by Starwaster
Added winky smiley so I don't come off as snarky
Link to comment
Share on other sites
Ricardo79

Ricardo79

Posted
Posted
....I just realized that you need a config to patch it for RCSFX. Raptors stock configs for RF is should have it. (If not now then next time he updates)

I am waiting for it impatiently :D As I do have that fix thing installed.

And it would be nice if there were KSP AVC support in the package. (Maybe it is there in the release then I am sorry. Right now I am using 405 dev build.)

If it comes out as a release I'D like to get noted.

Link to comment
Share on other sites
damerell

damerell

Posted
Posted
Yes, it's called Smart Translation. That's what turns on RCS Balancing. ;)

But I don't want RCS balancing. I want RCS not to be used for rotation by MechJeb.

I am happy to receive answers of that form, but only from people who read the question.

Link to comment
Share on other sites
Ricardo79

Ricardo79

Posted
Posted (edited)

Make a custom window. (custom window editor) And on that you can choose from the available options/infos/buttons And I am pretty sure there is that Use RCS checkbox or something. Just uncheck it.

(Rcs rotation (not intended) is more like a bad designed ship issue...)

I understand not all orbital base part should have an RCS thruster... So I use KAS and get rid of them (the surpluss) after the docking maneuvers.

Edited by Ricardo79
Link to comment
Share on other sites
Guest
This topic is now closed to further replies.
 Share
Go to topic listing
×
×
  • Create New...