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

[Cairan]

Am I the only one with issues on automated landings nowadays? Previously, MechJeb would land on a dime to a designated target, but now it tends 8 times of 10 to mistime the burns and I end up doing some high-G lithobraking... Seems it underthrotles and initiates the burn later than it should. Also, it now "chases" the landing target even on final descent. I don't know if something was changed, but normally it should just put the thing down safely even if we are off-course a little, say by a few hundred meters.

[Whitecold]

I have problems with Mechjebs Docking autopilot of lately. After I activate it, having selected both target and controlling docking port, it just wastes some RCS fuel before it idles with a message "moving to docking axis at 0.0m/s" aka doing nothing. Anyone knows this problem or even what to do about?

[Jason Cox]

I have problems with Mechjebs Docking autopilot of lately. After I activate it, having selected both target and controlling docking port, it just wastes some RCS fuel before it idles with a message "moving to docking axis at 0.0m/s" aka doing nothing. Anyone knows this problem or even what to do about?

I used to have that problem several versions ago; the solution for me always was to disengage the AP, thrust forward and then reactivate the AP.

The only issue I'm having (with regards to the docking AP) these days is that the AP now seems to fly straight toward the docking port while blowing through a ton of RCS whereas before the AP would, as in real life, first align itself with the target vessel and then slowly move toward it.

[Papa_Joe]

Am I the only one with issues on automated landings nowadays? Previously, MechJeb would land on a dime to a designated target, but now it tends 8 times of 10 to mistime the burns and I end up doing some high-G lithobraking... Seems it underthrotles and initiates the burn later than it should. Also, it now "chases" the landing target even on final descent. I don't know if something was changed, but normally it should just put the thing down safely even if we are off-course a little, say by a few hundred meters.

May or may not be related, but I saw something like this issue and realized I had SmartASS activated... seems SmartASS overrides any maneuvering... can be annoying when you are trying to figure out why your ship won't rotate 180 degrees when hitting circularize...

One time I went to land, and went into a 3 million meter orbit...

Edited October 31, 2013 by Papa_Joe

[Cairan]

Nah SASS is not enabled. As I said, this issue crops up often enough that now I just use it for the initial targeting burn, then I land manually... which is sad because even if I'm able to pilot it to a safe landing, I really enjoy MechJeb for surface base logistical missions.

[sarbian]

To get that fixed you'll need to post your ship and/or save, the planet you were landing on and the mods you use.

I tested my landing change with a lot of lander without trouble, so it may be a latter patch or a specific use case.

[Tassyr]

Does anyone know what I have to remove to get the game to stop considering mechjeb a pod? It's nice and all but the fact that the game always insists on using mechjeb as the main control device- regardless of what other command units were placed or when they were placed is getting annoying.

[a__gun]

Does anyone know what I have to remove to get the game to stop considering mechjeb a pod? It's nice and all but the fact that the game always insists on using mechjeb as the main control device- regardless of what other command units were placed or when they were placed is getting annoying.

Need to remove this:

MODULE
    {
        name = ModuleCommand
        minimumCrew = 0

        RESOURCE
        {
            name = ElectricCharge
            rate = 0.005
        }
    }

[sumghai]

Does anyone know what I have to remove to get the game to stop considering mechjeb a pod? It's nice and all but the fact that the game always insists on using mechjeb as the main control device- regardless of what other command units were placed or when they were placed is getting annoying.

I presume you could go into the AR-202's CFG and remove the MODULE{} definition corresponding to the Command Pod.

EDIT: dammit, ninja'd again!

[Acecool]

I'm trying to use Mechjeb in career however the parts are grayed out and say they lack something in the tech tree.

I changed the parts tech to require start, I've replaced the parts. I've uninstalled, launched, quit, reinstalled, launched, quit.... etc... I even downloaded someones entire settings folder which wasn't being created. I made it so HIDDEN is now NORMAL in the global settings. I've tried seemingly everything but it's not working, they remain grayed out even with

    TechRequired = start
    entryCost = 0   
    cost = 0
    category = Control
    subcategory = 0
    title = MechJeb 2 (AR202 case)
    manufacturer = Anatid Robotics
    description = A ruggedized version of MechJeb's neural circuits in a radial-mount case.

Any ideas?

[Tassyr]

Need to remove this:

MODULE
    {
        name = ModuleCommand
        minimumCrew = 0

        RESOURCE
        {
            name = ElectricCharge
            rate = 0.005
        }
    }

Thank you so much.

[sumghai]

I'm trying to use Mechjeb in career however the parts are grayed out and say they lack something in the tech tree.

I changed the parts tech to require start, I've replaced the parts. I've uninstalled, launched, quit, reinstalled, launched, quit.... etc... I even downloaded someones entire settings folder which wasn't being created. I made it so HIDDEN is now NORMAL in the global settings. I've tried seemingly everything but it's not working, they remain grayed out even with

-snip-

Any ideas?

Have you tried going into the R&D building, clicking on the first Tech Node and unlocking the MechJeb AR202 within the category?

[Acecool]

Have you tried going into the R&D building, clicking on the first Tech Node and unlocking the MechJeb AR202 within the category?

Wow, I never noticed that. I saw everything had owned when I clicked on them so I didn't notice that. Thanks so much!

[Galane]

May or may not be related, but I saw something like this issue and realized I had SmartASS activated... seems SmartASS overrides any maneuvering... can be annoying when you are trying to figure out why your ship won't rotate 180 degrees when hitting circularize...

One time I went to land, and went into a 3 million meter orbit...

Ships don't always burn retrograde to circularize. If the launch has exceeded the target orbit altitude, then a retro burn is needed to bring the altitude down, followed by a prograde burn to hit the horizontal velocity required for the target orbital altitude.

If MechJeb is burning to a higher orbit when you're wanting to land, it's most likely you have Control from here set to a part upside down with respect to the engines you are using to do the deorbit burn. It's especially easy to do with docked craft.

Deactivate the engines you're not going to use for deorbit then set control from here on a part of the other ship, the one with the engines you will be using. It's easy to check if it's upside down. In SASS click OBT and retrograde. If the craft points its nose instead of its engines in the direction it is orbiting, you've selected an upside down part or a part on the wrong docked craft.

Before the automatic adjusting ascent path, you had to always ensure the turn end altitude was no higher than the target orbit or Bad Things would happen (like rising to the target orbit height then nosing over and heading for the ground or spinning around and thrusting in various directions, or wildly gimbaling the engines during coast phase and breaking up the ship).

You still have to check the altitude setting, especially when you switch from launching from airless bodies to ones with atmosphere. Launching to a 15KM orbit on Kerbin, not a good thing... I just let the ascent path take care of itself and build to fly it.

I also found that those early auto adjust versions didn't work in KSP .21, even with the auto adjust turned off, it'd still do crazy things - so buh-bye went .21, hello .22.

[jtaylor996]

Ugh. The spaceplane autopilot is pretty terrible. Anybody else find it completely useless to use to land on the island runway?

When you land a plane, you control descent with the trhottle, and the speed with the pitch of the plane. Mechjeb appoarently doesn't know that is and is chasing the altitude with the pitch, and seem to use no control over the throttle at all.

Also, it needs to be getting it's altitude from the mean aerodynamic chord of the wing (center of lift), not from where the pod is located. This is required to get the control inputs smoothed out (so it's not oscillating all over the place in pitch, or if corrected, in throttle to get the correct altitude).

It would be useful if it could calculate an offset to the wheels as well (which depends on the angle of attack). This would prevent the problem of mechjeb crashing you in to the end of the runways.

Who's on these fixes

[Taris]

I compiled MechJeb2.dll with Mono to find out the output file was 'tad(about 500 kB)' smaller.

Here is the link for MechJeb2.dll compiled by MonoDevelop IDE(3.0.5.2, yeap, that one in Ubuntu repo...) with Mono C# compiler 2.10.8.1(Yeap, mono-gmcs in current Ubuntu repo...). Also, compiled with optimization option, without debug symbols. The OS was Gubuntu...errr Ubuntu GNOME 13.10. I checked the sources out yesterday (GMT -5:00) morning from the GitHub with 'git clone -b dev ~~~~'.

I'm just curious.. well, 500 kilo bytes are something can completely be ignored these days... Maybe I'm overly curious for a n00b without any experience in C#(actually, I don't have any professional experience in programming at all, just a few MATLAB scripts and VHDL codes to drive active matrix LCD displays...)

ps. I can use Mono compiled .dll in Windows KSP without any problem. Everything just works. Of course, I don't know how to compare plugin performances in KSP... but I didn't feel any notable difference either.

[keithkrause]

I don't seem to have all the options the screen shot shows. What I really want is Ascent Guidance but it isn't there. Did I not do something right?

[sarbian]

Let me guess, you are playing in Career mode ? You need to unlock more research node to unlock some functions.

@Taris This compiler most likely optimize more for size. I doubt that this help in any way, but why not.

[NNYGamer]

I looked back over the posts but didn't see my problem mentioned. Maybe I missed it. It may be my designs too.

Whenever I have mechjeb going to a maneuver node it seems to over control it. It spins around the long axis, over powers to the node, over shoots and goes back and forth. I've tied turning off all ASAS/SAS and gimbles, made sure the RCS was balanced but still it goes crazy. Turning of mechjeb lets me manually go to the node but it still over corrects/spins when I'm at it.

Even on launch it won't keep on track, it goes up and down. Same ship design worked fine with the old version.

[Jason Cox]

I looked back over the posts but didn't see my problem mentioned. Maybe I missed it. It may be my designs too.

Whenever I have mechjeb going to a maneuver node it seems to over control it. It spins around the long axis, over powers to the node, over shoots and goes back and forth. I've tied turning off all ASAS/SAS and gimbles, made sure the RCS was balanced but still it goes crazy. Turning of mechjeb lets me manually go to the node but it still over corrects/spins when I'm at it.

Even on launch it won't keep on track, it goes up and down. Same ship design worked fine with the old version.

I'm having the same issues. And not just with old craft upgraded from 0.21, but newly designed craft too.

[Starwaster]

I looked back over the posts but didn't see my problem mentioned. Maybe I missed it. It may be my designs too.

Whenever I have mechjeb going to a maneuver node it seems to over control it. It spins around the long axis, over powers to the node, over shoots and goes back and forth. I've tied turning off all ASAS/SAS and gimbles, made sure the RCS was balanced but still it goes crazy. Turning of mechjeb lets me manually go to the node but it still over corrects/spins when I'm at it.

Even on launch it won't keep on track, it goes up and down. Same ship design worked fine with the old version.

I'm having the same issues. And not just with old craft upgraded from 0.21, but newly designed craft too.

Is it possible your craft are just overpowered in that stage? What's the TWR and have you tried throttle limiting in Utilities?

[CrazyCanadian]

idunno, in general iv found the new mechjeb has some issues. a few things have been wonky. executing a node doesn't work if Smart A.S.S. is set to pro grade or something of the like. My pro grade and retro grade butons work but my kill rot is totally useless. doesn't work at all, used to work great in ksp .21.

so iv been using the stock SAS system to hold rotations in everything and using Smart A.S.S. for pro grade and the such. landing guidance has been less than accurate. and it doesn't seem to be calculating thrust when executing nodes.

but the Smart ASS is killing me, is there a solution to that issue?

[Galane]

When having MechJeb do maneuvers, click OFF on Smart A.S.S. and it goes to AUTO so MechJeb handles the rotations etc as needed.

[Jason Cox]

Is it possible your craft are just overpowered in that stage? What's the TWR and have you tried throttle limiting in Utilities?

Feel free to give her a test flight, but I doubt that's the issue. She worked great in 0.21 so I'm unsure if the issue I'm running into is an issue with MechJeb itself or another mod causing issues in active memory. I'm also seeing the issue with other crafts; wether they be upgrades from 0.21 or completely new builds.

Download Crew Transfer Vehicle Mk. III (craft file only)

Notes:

The CTV Mk. III is simple enough to fly, just activate Ascent Autopilot and she'll park herself in LKO. You should see the bug (where MechJeb keeps firing the engine and spinning around like crazy chasing the gimbal) at the end of the orbital insertion burn; if it doesn't crop up there, send a second CTV up and try the Rendezvous Autopilot.

Required Mods:

• MechJeb v2.1
  
• B9 Aerospace R4.0c
  
• Kerbal Attachment System v0.4.4
  
• Kethane v0.8
  
• KW Rocketry v2.5.4
  
• Procedural Fairings v2.4.2
  

[CrazyCanadian]

doesn't solve the fact that kill rot doesn't work ever... and mechjeb wont prevent jet flameout anymore...that function is also non working.