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

[CatastrophicFailure]

On other new Meumeu submitted a nice patch : This patch allows to modulate each engine thrust individually to launch unbalanced spacecraft, it also provides attitude control on the pitch and yaw axes.

You should find the checkbox to activate it in the Utilities windows.

By chance, would that build still work in .25?

[King Arthur]

Given that a lot of fuel flow logic and node handling needed to be rewritten with 0.90, among other things, I doubt that any of the MJ builds for 0.90 will work properly in 0.25.

[smjjames]

Solid rockets run at full thrust. They don't have a throttle, though some non-stock ones can have their burn profiles tweaked during assembly. If you put a big honking SRB on your rocket and it's not heavy enough to keep it from hitting terminal velocity on ascent, there's nothing you can do about that except add more weight.

MechJeb will throttle back throttleable engines (with stock aero) when SRBs ram into terminal velocity, if you have the TV limit engaged. Overpowering with SRBs is a nice way to save fuel in ascent. I've built some rockets with so much SRB power MJ will cut throttle completely from right after liftoff until SRB burnout.

With Stock Drag Fix (only aero mod I've used, it simply removes wet mass from being counted in stock drag calculation) MJ doesn't throttle back so much, often not at all, yet most of the time a lot less fuel gets used ascending from Kerbin and other places with atmosphere.

I understand and know that with the SRBs, I was just saying that with NEAR, it doesn't even try to change the throttle when I have 'limit to terminal velocity' on.

[nohey]

So for a few hours now i have been having real issues with Mechjeb. Only last night was Mechjeb working accurately and now it's simply broken without any change to the game, files, reason or ship usage. First all, my accent guidance is not working properly - the auto staging stops at stage 2 and won't continue (i have to do it manually past this point) fine okay. The guidence is now hugely out usually by as much as 100k or more on the AP - fine okay so i use a manoeuvre plan to correct the colossal mistake and use autopilot to execute this move. Nothing, it doesn't turn to the target on the navball at all. Fine okay so i do it manually, wait till the burn window - again nothing, doesn't fire the thrusters, nothing. At the moment it's just gone, the entire mod works in dribs and drabs.

Just for confirmation i have fully charged electrics, enough fuel to get to predicted ap and also when i have to correct orbit- not to mention it was working perfectly 24 hours ago.

I have reinstalled 3 times without any change.

Any ideas?

Thanks.

[smjjames]

@nohey, maybe something is breaking midflight? Use F3 to check the flight events log since if something broke, it'll be in there. Also, what does your ship look like?

Anyways, in addition to the previous post about issues with the landing, I tested it out a bit more with a proper lander (that is, with an engine under it and all) and it's still going at least a kilometer off target. Then I tried with 'land at target' (elsewhere this time) and it was still a kilometer off. For some reason though, it's actually better when I don't have RCS or an engine under it, or the tanks for them. I think it might be NEAR since before I put it in, the targeting was a whole lot better, should check that out. Edit: Okay, it actually works better without NEAR, so it looks like some problem in relation to the NEAR mod.

Edit: Also, I've got what looks like an actual bug, which is with NEAR active. During the final descent, the braking speed glitches out into some massive number with 12 rows of zeroes. It goes away when it does the actual braking burn.

Edited January 1, 2015 by smjjames

[nohey]

@nohey, maybe something is breaking midflight? Use F3 to check the flight events log since if something broke, it'll be in there. Also, what does your ship look like?

Hi James,

Nothing broke at all and the ship i am using is a small satellite launcher that i've used to launch sats into the orbits of Mun, Minmus and Kerbal for weeks. Yesterday i launched the same ship using Mechjab without problem and suddenly today it's going AWOL.

[Starwaster]

I understand and know that with the SRBs, I was just saying that with NEAR, it doesn't even try to change the throttle when I have 'limit to terminal velocity' on.

It will when the vertical component of your surface velocity exceeds your terminal velocity.

[smjjames]

It will when the vertical component of your surface velocity exceeds your terminal velocity.

Then how come it still does the mach speed visual effect and the re-entry plama effect even though I'm going up out of the atmosphere? I thought those effects meant I was hitting terminal velocity?

[Starwaster]

Then how come it still does the mach speed visual effect and the re-entry plama effect even though I'm going up out of the atmosphere? I thought those effects meant I was hitting terminal velocity?

Your terminal velocity is going to be a lot higher by the time you see those effects. Terminal velocity is the velocity at which the effects from drag forces equal the effects of gravity. It varies according to surface area, mass and air density

[ferram4]

Your terminal velocity with NEAR is probably something around 400 m/s at SL for a fully-fueled rocket. It's only going to get higher as you gain altitude. Stop thinking in terms of stock aerodynamics when you're running an aerodynamics mod.

[smjjames]

What's confusing me is that I thought the mach (sound barrier) and re-entry plasma effects meant that you were hitting terminal velocity. So, do they?

[Starwaster]

What's confusing me is that I thought the mach (sound barrier) and re-entry plasma effects meant that you were hitting terminal velocity. So, do they?

They do not.

Remove NEAR and replace it with FAR (temporarily) and you can open up a window which will show you how your terminal velocity increases with altitude (and decreasing air density)

When you get up to around 10km, your terminal velocity will be several kilometers per second

[Kaput]

Fairly sure the effects just mean you are going faster than x speed at y height. Hence why you get re-entry effects while launching if you go fast enough.

[smjjames]

@kaput and starwaster, okay, I get it now.

Also, theres a small bug that I'm seeing, sometimes when switching to a debris object (while flying another ship), it'll flip to a random asteroid instead. Incidentially, it just shunted me to an asteroid that appears to be en route to impact Kerbin. It's B class though.

Not sure if it's a Mechjeb bug though.

Edited January 1, 2015 by smjjames

[Commissar]

They do not.

Remove NEAR and replace it with FAR (temporarily) and you can open up a window which will show you how your terminal velocity increases with altitude (and decreasing air density)

When you get up to around 10km, your terminal velocity will be several kilometers per second

that's what i miss... the GUI is nice to have... i just set my acceleration to like 12m/s^2, untill i get to like .01 air density

[Pecan]

@kaput and starwaster, okay, I get it now...

Most importantly - if you're changing the aerodynamics with FAR/NEAR make sure you have a compatability patch of MechJeb.

[smjjames]

Is anybody else having an issue where if you have autostage on in the ascent guidance, select a target and do either rendevous, match plane, or interplanetary window so that it warps, and you click engage, the launchpad stability enhancers disappear with a bang? I actually had this problem a lot with previous dev builds, but I haven't seen that bug in a while. Until I suddenly started having it with this ship that I just made.

Here's the ship and output log:

http://sta.sh/02fujz5aym8l The only non-stock parts are a structural piece and the retro-rockets (using them as separators) from B9 Aerospace, and of course, MechJeb.

To reproduce:

1. Select a target (I was using Moho because that's where I wanted to go, but any target will work).

2. Make sure autostage is on.

3. select either launch to rendevous, launch into plane, or interplanetary window, it doesn't matter which one.

4. Engage autopilot and watch the launchpad stabilizers vanish with a bang when the autopilot starts the auto-warp.

Back when MechJeb was having this problem a lot, I found that I could bypass that bug by manually warping (using the warp helper also works without issue) close to the launch time and then engaging the autopilot from there.

I'm running FAR, but I had this problem a long while ago (shortly after the 0.90 release) where MechJeb constantly had this problem.

Edit: Oh, I'm using the latest dev build, 381.

Edit2: I think that ship may have some stability problems as it broke in half when coming out of manual warp. Wish we could extend the horizontial part of the stabilizers.

EDIT3: This ship is having the problem where if you click engage autopilot, it launches without player input as far as starting the engines. Wasn't this mentioned a whole bunch of pages back?

Edited January 3, 2015 by smjjames

[Starwaster]

Is anybody else having an issue where if you have autostage on in the ascent guidance, select a target and do either rendevous, match plane, or interplanetary window so that it warps, and you click engage, the launchpad stability enhancers disappear with a bang? I actually had this problem a lot with previous dev builds, but I haven't seen that bug in a while. Until I suddenly started having it with this ship that I just made.

Here's the ship and output log:

http://sta.sh/02fujz5aym8l The only non-stock parts are a structural piece and the retro-rockets (using them as separators) from B9 Aerospace, and of course, MechJeb.

To reproduce:

1. Select a target (I was using Moho because that's where I wanted to go, but any target will work).

2. Make sure autostage is on.

3. select either launch to rendevous, launch into plane, or interplanetary window, it doesn't matter which one.

4. Engage autopilot and watch the launchpad stabilizers vanish with a bang when the autopilot starts the auto-warp.

Back when MechJeb was having this problem a lot, I found that I could bypass that bug by manually warping (using the warp helper also works without issue) close to the launch time and then engaging the autopilot from there.

I'm running FAR, but I had this problem a long while ago (shortly after the 0.90 release) where MechJeb constantly had this problem.

Edit: Oh, I'm using the latest dev build, 381.

MechJebFARExt is throwing exceptions

MechJeb module MechJebFARExt reports an exception in OnStart: System.IO.FileNotFoundException: Could not load file or assembly 'FerramAerospaceResearch, Version=0.14.5.1, Culture=neutral, PublicKeyToken=null' or one of its dependencies.

I don't think that's the issue because it's pretty much all internal to MechJeb and it's trapping the errors and reporting them after.

Your launch clamps report being activated; no logging of them being destroyed or anything else happening to them. (activated just means they were loaded in and turned on... so to speak. Doesn't mean they disengaged or did anything in particular. Every part that loads in does that)

You might want to try removing StickyLaunchPadFix and trying again. I have nothing solid to base that on, there's no errors or anything logged about interaction between the two so it's just a hunch really. That's all I got right now.

[smjjames]

I checked back and yeah it's basically the same as what that higgs guy was experiencing, except without the spasm launching and his problems with polar orbits, and without the yelling too.

As for the launch clamps, they just vanish along with the bang sound that accompanies the unclamping. However, the thing is that I did NOT activate them, they seem to just activate themselves upon going into auto warp. I checked with one of my other ships and that one isn't having the problem.

The stickylaunchpad only applies to the tier 2 pad, and since I'm using science mode, it should be fine.

How did you know I had the stockbug fixes in there? Besides maybe seeing my post in the thread for it.

Edit: Removing that stickylaunchpad fix doesn't change anything. I did build the ship a bit oddly, so that may have something to do with it. So, I guess it's like mechjeb is going 'eep, that doesn't look very stable, launching NOW'

Edit2: After a few launch attempts, I've come to the conclusion that this rocket is simply designed badly.

Edited January 3, 2015 by smjjames

[Starwaster]

I checked back and yeah it's basically the same as what that higgs guy was experiencing, except without the spasm launching and his problems with polar orbits, and without the yelling too.

As for the launch clamps, they just vanish along with the bang sound that accompanies the unclamping. However, the thing is that I did NOT activate them, they seem to just activate themselves upon going into auto warp. I checked with one of my other ships and that one isn't having the problem.

The stickylaunchpad only applies to the tier 2 pad, and since I'm using science mode, it should be fine.

How did you know I had the stockbug fixes in there? Besides maybe seeing my post in the thread for it.

It's in your log file. It lists your mods. And if those mods want to log any debugging info that's in there too. That's why modders want the output_log.txt (or player.log if Linux/Mac)

[smjjames]

I've come to the conclusion that this ship is both designed poorly and a bit oddly since it was wobbling severely on launch and there is pratically a semi-flexible joint between stages. Which is probably why MechJeb is doing that.

Weren't higgs ships also designed poorly or something? I think someone said something to that effect. Here, I was just trying out something which ended up not working so well.

[Starwaster]

I've come to the conclusion that this ship is both designed poorly and a bit oddly since it was wobbling severely on launch and there is pratically a semi-flexible joint between stages. Which is probably why MechJeb is doing that.

Weren't higgs ships also designed poorly or something? I think someone said something to that effect. Here, I was just trying out something which ended up not working so well.

They had some issues, but I tested with them and didn't have any ill effects happen, other than what you'd expect from lack of struts in key areas. Nothing that was an issue in MechJeb interaction.

I'm not using too many struts these days myself though. In fact excessive numbers of struts can sometimes cause worse problems than they solve. I had one craft that I downloaded from the net that when launched just led to cascading structural failures and the more struts I added to fix the perceived problems, the worse it got. I think I fixed it by reducing the struts to key areas.

And I'm getting off topic a bit, but lately I've been experimenting with dephysicalizing all decouplers. Except for separators they don't really contribute anything by being separate physical attachments. Most of my rockets are as rock steady as with KJR and launches as smooth as a baby's bottom.

[smjjames]

After a redesign (used a single engine instead of the bicoupler I had going and placed the side boosters so that they were attached at the middle rather than at the engines I was using, everything else is exactly the same), MechJeb worked fine. Although it did make the launch clamps vanish twice on going into warp, but after a launch restart, it was fine, so, I dunno what's up with that. Want the output log from it?

Edited January 3, 2015 by smjjames

[BioHaZarD.PT]

What building upgrades are required to get full Mechjeb functionality in .90 career mode? I've yet to see the Landing and Rendezvous sections show up. I fully upgraded the Tracking Station and edited the part.cfg to get all Mechjeb functions early on the tech tree, but those things are still missing. What else do I need?

EDIT: Updating to latest dev version solved my problem.

Edited January 4, 2015 by BioHaZarD.PT

[skips]

I am getting an ArgumentException that appears to be coming from MechJeb. I am using KSP 0.90.0.705 (OSXPlayer) BETA and MechJeb Dev version MechJeb2-2.4.2.0-381. I can reproduce the error by moving a ship to the launchpad, opening the Maneuver Planner window and selecting Duna as the target. The log contains

[EXC 13:29:24.629] ArgumentException: Getting control 6's position in a group with only 6 controls when doing Repaint
Aborting
	UnityEngine.GUILayoutGroup.GetNext ()

	UnityEngine.GUILayoutUtility.DoGetRect (UnityEngine.GUIContent content, UnityEngine.GUIStyle style, UnityEngine.GUILayoutOption[] options)

	UnityEngine.GUILayoutUtility.GetRect (UnityEngine.GUIContent content, UnityEngine.GUIStyle style, UnityEngine.GUILayoutOption[] options)

	UnityEngine.GUILayout.DoButton (UnityEngine.GUIContent content, UnityEngine.GUIStyle style, UnityEngine.GUILayoutOption[] options)

	UnityEngine.GUILayout.Button (System.String text, UnityEngine.GUILayoutOption[] options)

	MuMech.MechJebModuleManeuverPlanner.WindowGUI (Int32 windowID)

	UnityEngine.GUILayout+LayoutedWindow.DoWindow (Int32 windowID)

	UnityEngine.GUI.CallWindowDelegate (UnityEngine.WindowFunction func, Int32 id, UnityEngine.GUISkin _skin, Int32 forceRect, Single width, Single height, UnityEngine.GUIStyle style)