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[1.12.x] Anatid Robotics / MuMech - MechJeb - Autopilot - [2.14.1] [1st April 2022]


sarbian
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1 hour ago, Gordon Dry said:

Could it be that "launch into plane of target" is not working on ascent guidance?

RSS: Earth -> Moon

There is an inclination set but not "used" anyway - launch goes straight to east.

When launching from a non-equatorial location, the launch azimuth (direction of take off) and final intended inclination will not match.

For Cape Canaveral a due east launch (at the right time of day) will put the vessel within about 0.25° of the Moon's orbital inclination (better if you do a slight dogleg on ascent).

I haven't played RSS in 1.3 but the 1.2.2 version of RO has no problems with targeting a launch to plane of Moon from the Cape.

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Screen%20Shot%202017-06-20%20at%205.26.2Is there any way to have the MechJeb tab be not here in the VAB. It's incredibly annoying and it gets in the way no matter where I put it. Maybe just disable the dropdown menu altogether and just use the sidebar (or even blizzy's toolbar) during flight?

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1 hour ago, spacedoctor42 said:

[snip image] Is there any way to have the MechJeb tab be not here in the VAB. It's incredibly annoying and it gets in the way no matter where I put it. Maybe just disable the dropdown menu altogether and just use the sidebar (or even blizzy's toolbar) during flight?

Did you try the "Hide Menu Button" in MechJeb's settings window?

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Edited by smurphy34
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On 6/17/2017 at 9:22 AM, sarbian said:

I am quite certain that the problem is in RCS BA. A long time ago an other mod had the same problem. It modified the stock GUI skin without cloning it first, so it changed the UI of other mods.

You are correct, and I've come up with a fix (I think).

I'm waiting for someone to confirm (I'm at work, can't really start up KSP right now)

Putting link here in case anyone want to try it, but I'm watching the RCS BuildAid thread about this.

https://www.dropbox.com/s/6ebvryoohq7rcxh/RCSBuildAidBetaSkinFix.zip?dl=0

FYI.  The author is not available, so this is mostly an unofficial build, although I think he is aware of my efforts.

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Hohmann Transfer does not seem to work correctly.   The planner will setup the burn, and the map will show the resulting orbits, with the SOI change.  yet after warping to the SOI change the orbit does not actually intercept the new SOI and last second burns are required to make the new orbit.  this is of course very wasteful of the fuel as the burn is not optimal at this time.

 

this is as far as I can tell happening 100% of the time I try to use the transfer to get to the Mün or Minmus.

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39 minutes ago, Bit Fiddler said:

Hohmann Transfer does not seem to work correctly.   The planner will setup the burn, and the map will show the resulting orbits, with the SOI change.  yet after warping to the SOI change the orbit does not actually intercept the new SOI and last second burns are required to make the new orbit.  this is of course very wasteful of the fuel as the burn is not optimal at this time.

 

this is as far as I can tell happening 100% of the time I try to use the transfer to get to the Mün or Minmus.

Manoeuvre Planner's Hohmann transfer works fine in most cases. Too well often as it will plot a collision course with the Mun unless you adjust the manoeuvre afterwards. How well you might be able to execute the node will vary depending on vessel design (especially TWR and balance - any off-centre thrust can have a big effect)  and whether you perform the burn manually or tell MJ to execute it.

Besides what sort of final orbit do you want after your transfer - prograde, retrograde, polar, rendezvous with a space station, landing orbit for a surface base? The options are too many to fit into a convenient interface. So instead you get an answer and the tools to tweak it to fit your specific requirements.

But you shouldn't just immediately warp to the destination after the burn. Even if you performed it perfectly there may be a need (especially with Minmus) to do a small correction half way and this is what Manoeuvre Planner's "Fine Tune" option is for.

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Hi all

 

Please forgive me if my appeal for help is in the wrong place or otherwise inappropriate or impolite. I appealed for help in the following thread:

http://forum.kerbalspaceprogram.com/index.php?/topic/162291-installed-mechjeb-but-cant-see-mechjeb-controls/#comment-3098143

Basically to summerize:

I am running KSP version 1.0.5 on a Windows 7 Professional (64-bit) computer. I am using a Steam version of KSP but not the computer that KSP was originally downloaded onto. Steam is not installed on this computer either, if that makes a difference.

I have tried using MechJeb2-2.5.6.0 and MechJeb2-2.5.6.1, which are (as far as I can tell) the appropriate versions for my version of KSP. 

I have attempted to install Mechjeb several times, starting with a clean copy of KSP on each occasion.

After each installation the Mechjeb parts become available in the VAB as expected, but the 'tabs' or controls to adjust the Mechjeb don't appear.

The error generated in KSP.log is always the same. I posted it in the above mentioned thread which is why I think people stopped replying to said thread. 

What am I doing wrong? 

 

Can anyone help? Alternatively is there an alternative Mod for me? I just want to be able to dock. That's all I need Mechjeb for. I can get two ships within 200 meters and 15m/s of each other fairly reliably. Getting rid on the remaining deltaV and distance has proven to be beyond me, which is why I need MechJeb's help.

 

many thanks and regards

Orc

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7 hours ago, Bit Fiddler said:

Hohmann Transfer does not seem to work correctly.   The planner will setup the burn, and the map will show the resulting orbits, with the SOI change.  yet after warping to the SOI change the orbit does not actually intercept the new SOI and last second burns are required to make the new orbit.  this is of course very wasteful of the fuel as the burn is not optimal at this time.

 

this is as far as I can tell happening 100% of the time I try to use the transfer to get to the Mün or Minmus.

Some comments on this:

1)  Things are modeled as if the burn is instant.  The greater the orbital rotation during the burn the greater the error will be, to the point that with an interplanetary burn with the Nerva engine from LKO is guaranteed suicide (flies you into Kerbin.)  When I use the Nerva I raise my orbit before doing a big burn.

2)  The Hohmann routine does not do plane changes.  Thus it is normal for it to fail to intercept anything not in your orbital plane--say, Minmus.  Ideally you start out with the planes matched, but if they aren't it's much cheaper to do a midcourse correction for Minmus than to match while in Kerbin's orbit.  Mun's orbital plane matches Kerbin's equator so that is normally not a factor when heading there.

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Does the MJ's 'execute node' functionality use some custom code for keeping my craft pointed at the maneuver node or something in the stock game handles that? I'm asking it because some of my big crafts tend to start oscillating continuously with greater amplitude around the node marker. The amplitude needs to be manually damped from time to time to make the execution anywhere near accurate. So I'm wondering whether it could be fixed in MJ or I'm stuck with whatever the stock game does.

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On 2017-6-27 at 5:21 PM, siimav said:

Does the MJ's 'execute node' functionality use some custom code for keeping my craft pointed at the maneuver node or something in the stock game handles that? I'm asking it because some of my big crafts tend to start oscillating continuously with greater amplitude around the node marker. The amplitude needs to be manually damped from time to time to make the execution anywhere near accurate. So I'm wondering whether it could be fixed in MJ or I'm stuck with whatever the stock game does.

Hi, 

IM seeing this oscillation on my craft. gradually over reacts to keeping pointing at prograde/man points.

Is there an option which will help? Im having to manually intervene which gets silly lol.

 

Best mod sayyyyy whaaat!

C

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I do match planes before the intercept burn, my CoT is aligned with the CoM, and all of this worked fine in previous versions of KSP/MJ.  so I was thinking something must have changed with the way KSP or MJ is doing things.

 

I noticed all this because I have a career game going and I made some communication sats to send to the Mün and Minmus.  it is the exact same sat for both and I had launched 1 to each body as a proof of concept before the 1.3 switch and everything worked perfectly.  and now fast forward to the present...  I am now ready to try and begin the exploration/colonization of the Mün and Minmus. so I am sending the rest of these sats to finish my constellations and the burn now no longer gets me to the desired SOI change point.  it is not missing it by a small amount either, it is missing it by about 500Km.  I know other mods that have updated may be causing this change in performance as well, but I figure I would ask here first, as it is the most obvious place for a change to have been made.

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On 6/7/2017 at 8:35 PM, Voodoo8648 said:

Is it possible to use Scripting Module to make a self automated probe like Voyager I & II? I'm early on into my career and don't have the technology for long range comm antennas but I want to send a probe to Eve and slingshot to Duna or Jool. I'd need the Hohmann Transfer planner to set up a maneuver after entering Eve's SOI, but it doesn't appear as though this is possible. Am I missing anything?

Hi,

This should be possible. Once you are on Eve's trajectory, you set the following actions:

- "Time" => "Warp to" and select "SOI change". This will wait until you enter Eve's SOI.

- "Target" => "Target body" and select "Duna".

- "Trajectory" => "Manoeuver" and select "Hohmann transfer to target"

- "Trajectory" => "Execute node" and select "next node". This will execute the manoeuver previously set

@sarbian Do you mind opening a Wiki access for me on the documentation so I can document the features of the Scripting module?

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Sometimes my MechJeb behaves strangely. One time, it burns toward the planet during circularization in ascent guidance mode, and I have to turn it off and circularize manually before the tin moron crashes my rocket. Another time, it botches landing on Tylo spectacularly. Is it the supposed behaviour of MechJeb?

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9 minutes ago, ave369 said:

Sometimes my MechJeb behaves strangely. One time, it burns toward the planet during circularization in ascent guidance mode, and I have to turn it off and circularize manually before the tin moron crashes my rocket. Another time, it botches landing on Tylo spectacularly. Is it the supposed behaviour of MechJeb?

As for the circularization:  I have seen two cases that can result in it going spectacularly wrong but both are predictable.

1)  The circularization burn is computed based on the engine you are using at the time.  It is quite accurate if you continue to use that engine but if you stage to a lower thrust engine during the burn (note:  there also is an issue that I do not understand, sometimes it can stage during circularization fine, sometimes it can't.  Any given rocket either works or must be manually staged.) it will be off on it's timing.  The bigger the thrust difference and the lower the target orbit the worse this will be.  If I'm going beyond LKO and not landing I use a Nerva engine for space use--and this really shows up the circularization problem.  The rocket I'm flying as I write this must be aimed to at least 120km up in order to survive circularization--and the result leaves the apoapsis twice the periapsis, the latter just barely outside the atmosphere.

2)  it will not consider the circularization burn until it leaves the atmosphere.  With a high thrust first stage (which makes for a less than ideal gravity turn) and a very low target orbit you can end up doing the burn late because it can't start it in time.  It touches atmosphere and doesn't know how to recover.

 

As for landings, I am aware of two issues:

1)  As far as I can tell both from behavior and from an admittedly not too deep look at the source code the land anywhere function is only safe if you have very little horizontal velocity.

2)  MechJeb's safety margins do not consider how fast the rocket can turn.  If a rocket isn't maneuverable enough (and note that the more gravity the more maneuverability it needs) it won't be able to point the engine correctly in time.  This is especially bad if the rocket is both hard to turn and very powerful.  (Beware fuel shuttles--powered to lift with full tanks but landing on nearly empty tanks.  Even on Minmus I've watched them get into an overcorrection loop and smack the ground without ever trying to stop.)

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8 hours ago, SPD13 said:

@sarbian Do you mind opening a Wiki access for me on the documentation so I can document the features of the Scripting module?

Add a page on the github wiki. I gave you push access to the repo to make things easier.

Edit : actually the wiki should not require any special access.

Edited by sarbian
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