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

[DerekL1963]

Ok, why in heck can't I land on a target on Eve?

Anytime I select or enter a target, it performs the de-orbit burn, then a xxm/s course course correction, then a minute (or more) long .0xm/s or .00m/s "course correction" - and then it goes dead. It stays suck in "coasting towards deceleration burn" mode and flies right into the terrain. The only way to get it to perform any kind of a landing at all is to wait until I'm 10km or so up, abort autoland and select "land anywhere" - at which point it updates to final descent mode and lands 'normally'.

[Secret Squirrel]

Ok, why in heck can't I land on a target on Eve?

Anytime I select or enter a target, it performs the de-orbit burn, then a xxm/s course course correction, then a minute (or more) long .0xm/s or .00m/s "course correction" - and then it goes dead. It stays suck in "coasting towards deceleration burn" mode and flies right into the terrain. The only way to get it to perform any kind of a landing at all is to wait until I'm 10km or so up, abort autoland and select "land anywhere" - at which point it updates to final descent mode and lands 'normally'.

Not a fix but I have noticed if you abort autoland after the deorbit burn and wait a second and select autoland again it works better. For me at least, something to try. If I am going for a targeted landing and don't do that Ill land 100+m away from target but if I cycle it I'm always right within 5m of my target.

[Galane]

MechJeb is still altering the stage assignments for engines. http://pastebin.com/jSQTHXF9 The only mods that one needs are ReStock for the monster solid boosters and the very long tanks, and the large inline reaction wheel from KSPX.

It launches smooth towards a 71KM orbit with corrective steering on, the SRBs drop and it keeps going for a while just fine until suddenly the upper stage engines get activated and moved down to the first stage and the rocket goes out of control. That. Should. Never. Happen. If the rocket doesn't have enough thrust in the current active stage, do not try to "fix" things by activating more engines somewhere else on the vehicle.

This is a WIP design for one half of the booster that will go under my WIP 32,000 unit Kethane mining lander - but testing is a bit difficult when MechJeb decides to stick a finger in where it shouldn't.

[sojourner]

In all the time I've used mechjeb I have never had it reassign engines to different stages. Are you positive the rocket isn't breaking in some way? what does it say when you hit F3 at the point where it fires up those engines and goes out of control? It sounds suspiciously like the rocket is breaking somewhere below your upper stage, which would have 2 results.

1. The lower stage will keep firing and still show in the stage list.

2. Mechjeb will fire the upper stage engines and try to continue to orbit.

Edited October 27, 2013 by sojourner

[peluche399]

or turn off autostage. then its impossible.

but like sojuurner said I would be willing to bet my hat your rocket is breaking and MJ is just moving to the next available stage. remember that when a rocket breaks off of a ship while firing it continues to fire out of control.

[Galane]

Did you actually fly the rocket to see what it's not doing right?

Here is a version that I finally got to stop it lighting up the upper stage engines. http://pastebin.com/Gepq13w4

That's after multiple versions of adding more engines at the bottom. The version just prior to this only had fuel pipes going from the big tanks to the small ones. When the fuel ran low in the big tanks, MechJeb would light up the pair of poodles in the upper stage. I flew it that way a few times and *every time* until I added the other pipes it'd do that.

The only change from that one to this one is I added fuel pipes running back from the small tanks to the large ones so all the engines will run out at the same time.

I've had this happen many times on rockets that are pushing the low end of TWR in a stage, with nothing wrong structurally - until after MJ goes looking for more thrust.

I did add four struts crossed between the orange tanks and the large tanks, and two more struts from the orange tanks to the nosecones on the SRBs, but that was to counteract the breaking from the downward jerk when physics kicks in. No other changes to the main stack.

Before switching to LV-30's added, I tried skippers but the throttle up after the SRBs dropped was too much and it all came apart. Turning off terminal velocity limit was also not a success with that configuration. Same as the original LV-30 config, I only had pipes running from the big tanks to the small tanks above the skippers. Too much thrust with too abrupt throttle control. Before that, I tried adding first four, then eight of the white, radial mount engines. The more power I added, the higher altitude it'd reach before MJ would fire the upper stage.

MJ could really use a throttle response speed control, ideally settable per stage. Would reduce the need to spam a rocket with struts just to handle the throttle abuse MJ dishes out.

Buggy Booster is going to need the poodles upgraded to skippers and possibly will need some more engines strapped onto its upper stage. Two of the LV-30s will get moved so all four will be on one side because two of these stacks are going under the tandem 16K tank kethane mining lander. Might have to lash on some more Rocko Monster SRBs too.

Something has changed in this since the 2.0.9 release. MJ 2.0.9 in KSP 2.1 would blow up this one http://pastebin.com/HmBZ2WgW by firing the separatrons and the LV-909 at the same time. (Yes, I tried it several times.) To make it not do that I had to swap the stage positions of them, pairing the separatrons with the decoupler. I just tested it, reverted to the configuration (as pastebinned) that didn't work before, now it works in .22 with MechJeb 2.1.0.0-92 Other than the micro reaction wheel from KSPX, that rocket is stock parts.

BUT there's still the issue that MJ will not auto stage the final on the missile, no matter which way they're ordered. (I'm going to put it back the way it was, with the separatrons going first because it missed the target this time by a long ways with the separatrons as stage 0.)

I have a couple of manned landers that MJ will not auto stage the lander engine even though it is paired with a decoupler. Start the landing with just a little fuel in stage 1 and MJ will let the ship crash instead of popping off the dry stage and lighting up stage 0. I should try this with my Kethane rovers on the Mun. When making the first landing I manually stage off stage 1 because the landers have to make it down on the fuel they have onboard. Could test by first stopping at one of the refineries and draining all but a little fuel then go to land and see if MJ will do the staging properly.

[sarbian]

There is no code in MJ to move part in the staging list. When an engine goes down to the last stage it is when it start and the game move it.

I just tried your first file 3 time. The first time it broke under its own weight on the launch pad, the 2 other times there was a structural failure.

With the second version I had to add strut for it to not cut itself in two after take off, and even then it ended with the same message than the first one :

"Structural failure on linkage between Rockomax Jumbo-64 Fuel Tank and Bigger Badder Bi-Coupler."

After that MJ think that the upper engine are the only one left and start them, making things worse.

But the problem is the structural failure.

[mwlue]

errr, is AR202 essential for mj??

MODULE

{

name = MechJebAR202

}

i found this module causing ****loads of "NullReferenceException: Object reference not set to an instance of an object" and seems to be the cause of fps drop on me. after commenting out AR202, the NullReferenceException is gone.

[sarbian]

Did you add the MechJebAR202 module to something else than the AR202 ? This module control the light on the AR202, so on a part that don't have the light your get errors

[mwlue]

Did you add the MechJebAR202 module to something else than the AR202 ? This module control the light on the AR202, so on a part that don't have the light your get errors

it causing NullReference even with AR202 attached to my rocket. so it is just about lights and no other function?

[a__gun]

If any of MechJeb's modules are active the green light is shown, otherwise the red light, the MechJebAR202 module is what controls this and only this - so yes you can remove it without it breaking anything else.

As sarbian says, if you add this module to any parts that dont use the AR202 model then it will cause issues.

[sojourner]

Did you actually fly the rocket to see what it's not doing right?

No, I had no interest in loading up the mods required. Did you hit F3 at the time of the problem to see what sequence of events took place?

Your rockets are breaking in half. MOAR STRUTS.

As for your landers. I am not sure landing autopilot stages in Mechjeb. I don't build multistage landers.

Edited October 27, 2013 by sojourner

[Guest]

As for your landers. I am not sure landing autopilot stages in Mechjeb. I don't build multistage landers.

MechJeb does not autostage landers. You have to switch off the autoland function, adjust the vehicle's orientation if necessary, eject the stage, then resume autoland. Make sure the ejected stage is clear, because the MJ will immediately perform a correction burn to account for the change in mass.

[Bromoc]

Is there a way to add columns to the Delta-V stats? I'm working on a formula to determine how a stage contributes to an ascent. Manually inputting the data in excel is starting to get annoying. And once I am done, would like to contribute the forumla to the mechjeb team.

[Starwaster]

Is there a way to add columns to the Delta-V stats? I'm working on a formula to determine how a stage contributes to an ascent. Manually inputting the data in excel is starting to get annoying. And once I am done, would like to contribute the forumla to the mechjeb team.

Is there something wrong Tsiolkovsky's rocket equation??? It's worked great for a number of space fairing nations for decades!!!

[Cryphonus]

I have a strange problem with my mechjeb. I decided to start my carreer mode from scratch and created a new save. My mechjeb is quite limited, i can only see vessel info, orbital info and some other buttons. There is no ascent guidance no landing autopilot there is nothing that uses automation. When i leave my landing autopilot window on from the sandbox carreer i can use it in the carreer mode but when i close the window i can't open it again because it just doesn't show up in the GUI. Here are some facts:

- I changed nothing about mechjeb and it functions normal in my other savegames, it doesn't function in my newest savegames.

- I set the requiredtech to "start" long ago so its not related with that.

- As i said, GUI is partially there containing only information buttons such as orbital info Delta-V stats and vessel info, rest of the buttons are not there.

What is wrong?

-

[johnsonwax]

What is wrong?

You have to earn the individual features in the tech tree.

[Cryphonus]

You have to earn the individual features in the tech tree.

Is it how it functions now? If so i gotta say i am impressed

[johnsonwax]

Version 2.1

Changed the way MJ searches for Modules in other assemblies so a module in an assembly that failed loading doesn't fail loading for everything;
Move MJ2 Button with right click, drag & drop;
Docking Autopilot Improvement;
Let user force Roll for Smart ASS and Docking AP;
Improved Attitude controler;
Fix for some ship turning to circularize while still in atmosphere;
Fix exception spam when launching a vessel with no saved MJ2 setting directly form the Space Center screen;
Improved RCS control for Docking;
Added a stock-SAS toggle to Attitude Adjustment;
Landing Guidance control for Parachutes and Legs;
Fixed runway positions for 0.22;
[B]Added support for selective module unlocking for Career mode;
[/B]

[Estel]

have someone else noticed a big increase in monopropellant usage while docking? i had a ship in .21 with sarbian version that was able to dock 5 or six times before needing monoprop refuel, now is not even enough for docking once. From what i can see this version doesn't use reaction wheels to help keeping the ship orientation, it continues to compensate with rcs, rapidly draining it. Can someone look into it?

Another minor bug i experienced is the SmartASS not switching to auto when autoLanding\manouvering, the ship can't orient on the manouver node, it remains 5-10 degrees off.

[Wijbrandus]

You have to earn the individual features in the tech tree.

How do I put it back to how it was?

I'm not interested in unlocking the features through science. I would rather have all the MechJeb features from the start, like in the Sandbox.

Nevermind, I figured it out. Just delete the "unlock" requirement lines, in case anyone else wants to know.

Edited October 27, 2013 by Wijbrandus
updated

[Starwaster]

How do I put it back to how it was?

I'm not interested in unlocking the features through science. I would rather have all the MechJeb features from the start, like in the Sandbox.

Nevermind, I figured it out. Just delete the "unlock" requirement lines, in case anyone else wants to know.

In the AR202 module I suppose?

[mjones1052]

After loading up MJ 2.1 does anyone else see a huge increase in the time it takes to load when you first launch the game and it's running through all your plugins? This normally takes 1-2 minutes for me. Once I load up MJ 2.1 it stops about 1/3 through and never starts again. I go back to 2.0.9 and I'm fine. Install 2.1 and it's messed up again.

I'm assuming it's a conflict since no one else seems to have it? The plugin loading seems to hang up on B9. Any known compatibility issues?

[mjones1052]

Is there something wrong Tsiolkovsky's rocket equation??? It's worked great for a number of space fairing nations for decades!!!

Well, you can add a custom window. Is this not what you're looking for? I'm guessing you mean not using the pre-determined categories from the list and using your own formula? You could possibly find the DeltaV window in the code and plug everything in?

[Bromoc]

Is there something wrong Tsiolkovsky's rocket equation??? It's worked great for a number of space fairing nations for decades!!!

Nothing wrong with his equation. Mechjeb doesn't give me the results. I'm trying to come up with a metric that allows me (if not others) at a glance to see there ship can achieve a certain orbit at a certain distance, at a certain planet. And you fail to answer my question. how do I add a column to the delta-V window?