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

[sarbian]

Sabrian's version seems works fine in 0.22.

Don't use my version anymore, all my change and more are in the official dev version.

If you want to use the lastest version user the dev version link from the first post ( http://jenkins.mumech.com/job/MechJeb2/ )

[mwlue]

Don't use my version anymore, all my change and more are in the official dev version.

If you want to use the lastest version user the dev version link from the first post ( http://jenkins.mumech.com/job/MechJeb2/ )

Arr ok, noted with thanks.

[randommonicle]

Hello all,

Love this little bit of kit. Really helps. I was just wondering if anyone could give any advice? Im trying to use its landing assist feature, and the maneuver planner to get to the mun, but when it hits the moment to initiate the burn, to either head out to the mun, or to land back on kerbin, then it simply does nothing, and the countdown goes in to the t+'s. Is this down to an improperly designed spacecraft? Or am i doing something wrong?

Thanks everyone.

[DerekL1963]

Don't use my version anymore, all my change and more are in the official dev version.

If you want to use the lastest version user the dev version link from the first post ( http://jenkins.mumech.com/job/MechJeb2/ )

The current dev version (build 83) does not however play well with the new SAS. It can't maintain attitude worth a dang.

Love this little bit of kit. Really helps. I was just wondering if anyone could give any advice? Im trying to use its landing assist feature, and the maneuver planner to get to the mun, but when it hits the moment to initiate the burn, to either head out to the mun, or to land back on kerbin, then it simply does nothing, and the countdown goes in to the t+'s. Is this down to an improperly designed spacecraft? Or am i doing something wrong?

You do have power and sufficient attitude control authority?

[a__gun]

Don't use my version anymore, all my change and more are in the official dev version.

If you want to use the lastest version user the dev version link from the first post ( http://jenkins.mumech.com/job/MechJeb2/ )

Sarbian you should really get that thread closed or just edit the first post to tell people to head back to this thread...or both lol

[Troberg]

My rocket is very tail-heavy, and has plenty of gimbaled engine power, all at the bottom. Also have plenty of RCS and a few fins.

Depending on lifter configuration, it's a 1000-2000 ton vessel, with a 150 ton payload.

Does it matter where the "control from" part is located (direction is forwards, but it's a bit off center).

[Payload]

Alright guys.

I DLed the latest dev version.

Problem, the ship tries to make a 180 deg roll right off the pad. Now that is using one of the stock command pods as the mech jeb unit but my old version never did that. It is rolling until the POD faces north. That is usually not a problem but if you have a ship that needs a little speed before it has control authority it will never make the roll. It causes the ship to wobble all over the sky.

It's like it is trying to force roll even though I have that unchecked. You should not be forcing roll off the pad. People orient the ship how they want in the VAB. Stock VAB rotation is 180 degrees. MechJeb is trying to force roll 0 right off the pad. That needs to stop. It never did that before. Even the last version I had that had force roll didn't have that problem.

[drippygoo]

i downloaded this, and its not showing in Career mode. is there something special i need to do?

i got the one from here

http://jenkins.mumech.com/job/MechJeb2/

got it working

had to add a thing to the part file

Edited October 18, 2013 by drippygoo

[sarbian]

It does however save fuel, when you deploy parachutes, your predicted landingsite is garbage though.

Not anymore ! Coming to a dev version in the next 24H.

[MOARdV]

Problem, the ship tries to make a 180 deg roll right off the pad. Now that is using one of the stock command pods as the mech jeb unit but my old version never did that. It is rolling until the POD faces north. That is usually not a problem but if you have a ship that needs a little speed before it has control authority it will never make the roll. It causes the ship to wobble all over the sky.

That happens to me on occasion (not every time, usually after several launches). If you look at the roll indicator in the lower-left corner before launch and you see the needle is all the way to one of the sides, tap Q or E (the roll buttons) and it will reset to center.

[Galane]

Does it matter where MechJeb is on the craft, as long as it's pointed in the right direction?

I have a large craft that tends to tip over at around 20-30000m during launch, even though center of gravity and center of thrust are perfectly aligned and I have plenty of RCS as well as gimbaled engines. I really want to do a successful launch with this beast.

Do you have corrective steering on or off?

[Galane]

Alright guys.

I DLed the latest dev version.

Problem, the ship tries to make a 180 deg roll right off the pad. Now that is using one of the stock command pods as the mech jeb unit but my old version never did that. It is rolling until the POD faces north. That is usually not a problem but if you have a ship that needs a little speed before it has control authority it will never make the roll. It causes the ship to wobble all over the sky.

It's like it is trying to force roll even though I have that unchecked. You should not be forcing roll off the pad. People orient the ship how they want in the VAB. Stock VAB rotation is 180 degrees. MechJeb is trying to force roll 0 right off the pad. That needs to stop. It never did that before. Even the last version I had that had force roll didn't have that problem.

Something to note is that the build in the VAB gets rotated 90 degrees when placed onto the pad. For example, if you build a rover oriented so it should be able to roll out the door and up the ramp, it gets plopped sideways onto the pad when you click launch. Why does it break with the visuals that way? Is what's seen out the VAB door the same virtual environment as the outdoor launchpad area or is it a separate "set" where for some reason it's always daylight? I never noticed the rotation until I built a rover.

[ocbaker]

Is it possible for Mechjeb to have it's own science tree? And each function of Mechjeb was unlockable.

I.E: You unlock the AR-202 then you have to unlock ascent, overheating assist etc.... This would make Mechjeb feel much more balanced in the scope of Career mode.

[jpkerman]

Is it possible for Mechjeb to have it's own science tree? And each function of Mechjeb was unlockable.

I.E: You unlock the AR-202 then you have to unlock ascent, overheating assist etc.... This would make Mechjeb feel much more balanced in the scope of Career mode.

+400 It would be a function advancement instead of an new part being added. If that works then you could have other parts that could add functions rather than becoming out-dated.

[Nostromo]

Not sure if I posted in the right area but found an issue with MechJeb 2.0.9 : http://forum.kerbalspaceprogram.com/threads/53848-Possible-MechJeb-2-0-9-Spaceplane-Autoland-Issue-in-0-22-Suggestion

[jztemple]

Once in orbit around Kerbin:

1) Go to map view, and select the Mun as a target.

2) Go to MJ Manoeuver Planner and select Hohmann Transfer to Targer and click Create and Execute Node.

3) After the burn, go to MJ Warp and select SOI and WARP

4) Once in the Mun's SOI, go to Manoeuver Planner and select Change Periapsis, enter your altitude and click Create and Execute Node.

5) After the burn, in to Manoeuver Planner and select Circularize, specify at Periapsis and click Create and Execute Node.

6) To land, go to Landing Guidance, set your coordinates and Auto Land.

You can avoid step 4 (and save fuel) if you edit the Manoeuver Node before burning in Step 2, but you wanted foolproof. Ideally, the Hohmann Transfer should have settings for a target Periapsis and whether you want a prograde or retrograde orbit at the target.

This explanation has been very useful to me when going to the Mun and Minmus. Hell, it's probably the only way I go there now. However, the other planets and especially the moons of other planets have been giving me a hard time. Would Nibb31 or some other guru please post similar foolproof instructions like the above for going to other planets and their moons? Thanks for any help you can give.

[Dingbat1967]

Could someone explain to me the difference between the mechjeb file downloadable from the start of this thread and a mechjeb file that I found in the spaceport that actually seems to contain a folder of modified parts from the gamedata\squad\parts\command section?

I'm trying to fix mechjeb in Sandbox mode on my KSP 0.22 but I did not have the AR-202 folder or anything like that.

[Dingbat1967]

Never mind, I think I figured it out. In the KSP Spaceport, there's a Mechjeb entry from a guy called "The White Guy" that rolled up something into the default parts of KSP some mechjeb lines for each component. Now that kinda sucks now because that means my current save game with all my ships (I have a Massive Space Program going on in sandbox mode) are going to lose mechjeb and I can't just retroactively add the module (I think). I'll see if I can manually modify my files but I wish the stupid spaceport was better organised. Had I known this was not the "correct" way ...

MODULE

{

name = MechJebCore

RESOURCE

{

name = ElectricCharge

rate = 0.005

}

}

Edited October 19, 2013 by Dingbat1967

[Troberg]

Do you have corrective steering on or off?

Tried both. Also, tried to not limit to terminal velocity (that's the reason for the 2000 ton lifter...), the idea being that more engine thrust would provide more powerful steering to gimbaling engines.

The thing is, as long as it's vertical, it's fine. But, as soon as it tips over, even if just a little, it will continue to tip over into a tumble. (I've actually almost made orbit once, despite doing two full tumbles on the way up, but I didn't manage to get it into a stable heading for the circulization burn before the orbit declined...)

For really heavy vessel, it would be really nice if it was possible to use ordinary engines for steering, instead of RCS. Just put a bunch of sideways poodles on the ship (or, if you are Whackjob level insane, mainsails ), and have the RCS system control them. Perhaps some talanted modder out there who feels inspired?

[BloodyRain2k]

Tried both. Also, tried to not limit to terminal velocity (that's the reason for the 2000 ton lifter...), the idea being that more engine thrust would provide more powerful steering to gimbaling engines.

The thing is, as long as it's vertical, it's fine. But, as soon as it tips over, even if just a little, it will continue to tip over into a tumble. (I've actually almost made orbit once, despite doing two full tumbles on the way up, but I didn't manage to get it into a stable heading for the circulization burn before the orbit declined...)

For really heavy vessel, it would be really nice if it was possible to use ordinary engines for steering, instead of RCS. Just put a bunch of sideways poodles on the ship (or, if you are Whackjob level insane, mainsails ), and have the RCS system control them. Perhaps some talanted modder out there who feels inspired?

As far as I know was there already a mod that allowed the use of engines for RCS.

Though you could just make highpower RCS thrusters that just eat more fuel, or just add wings.

And I think it's time to show a screen of your monster because it seems you're lacking control over it when it can't even counter a slight tip to the side.

[CatastrophicFailure]

This explanation has been very useful to me when going to the Mun and Minmus. Hell, it's probably the only way I go there now. However, the other planets and especially the moons of other planets have been giving me a hard time. Would Nibb31 or some other guru please post similar foolproof instructions like the above for going to other planets and their moons? Thanks for any help you can give.

Quick version:

1. Get into orbit

2. Select an interplanetary target.

3. Select interplanetary transfer in mechjeb. It will probably give you a node days or weeks in the future. This will take a LONG time waiting in LKO due to the time accel limit. I strongly suggest getting Kerbal alarm clock so you can set an alarm for this node, switch to something on the ground or in high orbit, then time accel till it's time. Note that with this maneuver node created by mechjeb you probably WILL NOT see an encounter in map view. Trust the box, mechjeb isn't the most efficient interplanetary planner but it will get you there and you will learn how to finesse it on your own as you progress. Anyways...

4. Once you're a few minutes from your node let MJ fly it. Time accel till you're just outside of Kerbins SOI, then select "fine tune distance to target". You may have to reset your target as well. This maneuver SHOULD get you an encounter and again will be many days in the future but now you can time accel all the way.

5. After this correction node you may need to do it again as you near your target. Even two or three times. Once you're in your targets SOI you can fine tune your desired periapse. The way the game estimates & rounds numbers while under time accel your peri isn't really accurate till you're in the new SOI

6. Once you're this far set up an aerobrake, powered capture burn, etc.

7. Once you've got an orbit around a planet, THEN work an an intercept to its moon.

Ok that wasn't so quick. Once you've been thru this a few times you'll get the hang of how the mechanics work and you'll figure out how to tweak MJ's nodes and/or add your own for a more efficient flight. Mechjeb also generally does not give you the most efficient transfer window when going to a highly inclined target like Moho or Dres, and Eeloo just confuses the hell out of it. Timing your encounter to the AN/DN is still trial & error but you should be able to get to Duna, Eve, or Jool with just a few clicks.

[CatastrophicFailure]

This. Also consider more reaction wheels. Myself, I almost never put RCS on a craft unless it needs dock.

[Galane]

Match planes with the target first, then setup the Hohmann transfer. That step isn't automatically done like it is in Rendezvous autopilot. What if you get out of Kerbin SOI, then match planes with the target plant, then do the Hohmann transfer?

The latest development release MechJeb2-2.0.9.0-83.zip of MechJeb does not play nice with KSP .21 I tried it to launch the rovers I have on Minmus and it would not light the engines for the circularization burn.

Tried a launch from KSP and despite incliniation set to 0 it'd take off with an immediate slight turn *east* then at the gravity turn start it'd just keep going over and head for the ground.

It seems to work in .22, at least for the one launch I did in a vanilla setup with no mods other than MechJeb. Launched, turned and circularized just fine.

The -83 release has an automatic turn height adjuster which changes according to the altitude set in Ascent Guidance. Doesn't matter if that's on or off, Ascent Guidance just doesn't work right in .21 with that release.

This one MechJeb2-2.0.9.0-82.zip works properly in .21

Get 'em here. http://jenkins.mumech.com/job/MechJeb2/

Edit: WTH? I was sure I had the -82 release working in .21 last night. Just tried rolling back to it and same problems, it's completely out to lunch on ascent guidance. I'll have to try older releases until I find the newest one that works - or see if .22 will go with all the mods at half texture resolution setting.

Edited October 19, 2013 by Galane

[jztemple]

Quick version:

1. Get into orbit

2. Select an interplanetary target.

3. Select interplanetary transfer in mechjeb. It will probably give you a node days or weeks in the future. This will take a LONG time waiting in LKO due to the time accel limit. I strongly suggest getting Kerbal alarm clock so you can set an alarm for this node, switch to something on the ground or in high orbit, then time accel till it's time. Note that with this maneuver node created by mechjeb you probably WILL NOT see an encounter in map view. Trust the box, mechjeb isn't the most efficient interplanetary planner but it will get you there and you will learn how to finesse it on your own as you progress. Anyways...

4. Once you're a few minutes from your node let MJ fly it. Time accel till you're just outside of Kerbins SOI, then select "fine tune distance to target". You may have to reset your target as well. This maneuver SHOULD get you an encounter and again will be many days in the future but now you can time accel all the way.

5. After this correction node you may need to do it again as you near your target. Even two or three times. Once you're in your targets SOI you can fine tune your desired periapse. The way the game estimates & rounds numbers while under time accel your peri isn't really accurate till you're in the new SOI

6. Once you're this far set up an aerobrake, powered capture burn, etc.

7. Once you've got an orbit around a planet, THEN work an an intercept to its moon.

Ok that wasn't so quick. Once you've been thru this a few times you'll get the hang of how the mechanics work and you'll figure out how to tweak MJ's nodes and/or add your own for a more efficient flight. Mechjeb also generally does not give you the most efficient transfer window when going to a highly inclined target like Moho or Dres, and Eeloo just confuses the hell out of it. Timing your encounter to the AN/DN is still trial & error but you should be able to get to Duna, Eve, or Jool with just a few clicks.

Thanks for the help, I'll give this a try

[Nostromo]

Can't seem to get the Docking autopilot to work at all even following the steps, trying different designs, etc. I can see it using the RCS thrusters but it does not try to dock at all. Just floats around.