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[1.8.x] Anatid Robotics / MuMech - MechJeb - Autopilot - [2.9.1] [15 November 2019]

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3 minutes ago, JH4C said:

But the latest version built for 1.5.x has been 2.8.1 since mid-week. That would be why you're getting an error message. https://ksp.sarbian.com/jenkins/job/MechJeb2-Release/

JH4C, thank you for the courtesy of your reply.

I got mine from the dev side, which is here - https://ksp.sarbian.com/jenkins/job/MechJeb2-Dev/

...and even right now is still showing 2.7.4,  though 812 was released about 14 hours ago. I honestly don't pretend to understand , but that's what happened :)

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I don't think the Dev side's been updated to 1.5.x yet; @Jim DiGriz has been working on the orbital transfer stuff in the older codebase, hopefully it'll pop up in the release version too.

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3 hours ago, JH4C said:

I don't think the Dev side's been updated to 1.5.x yet; @Jim DiGriz has been working on the orbital transfer stuff in the older codebase, hopefully it'll pop up in the release version too.

dev will work fine in 1.4.x or 1.5.x just ignore the compatibility check.

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short Q: is it possible to blacklist the ;settings,flightrecorder,utilities and aircraftautopilot or hide the icon for one of them

have tried dozent variations,but no luck

 

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The new bi-impulsive transfer is great! I'm regularly saving 700-1000 deltaV on each trip to Moho compared to the old transfer method. Can't wait to go moon-hopping around Jool :P

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2 hours ago, Gorby1 said:

The new bi-impulsive transfer is great! I'm regularly saving 700-1000 deltaV on each trip to Moho compared to the old transfer method. Can't wait to go moon-hopping around Jool :P

Hah, I forgot about that, of course it works interplanetary as well if you escape first.  Can you beat the advanced transfer to another planet function or do you just prefer to eject out of the SOI first then Hohmann transfer?

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I'm a little confused as to the landing autopilot. I know there's a bug with "land at target", when do I have to engage it to keep it from getting stuck at course correction?

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Also, when I engage the landing autopilot, it will go from being right on target to saying it's off course by ~25 km. It's on target and agrees with Trajectories until I engage the landing autopilot, then the prediction becomes off about 25 to the east. This was on the Mun

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On ‎10‎/‎15‎/‎2018 at 3:58 AM, Jim DiGriz said:

- The MechJeb you are using with 'A' and 'B' numbers is Atlas-Centaur "PEG" (which is not PEG)

- To get Shuttle PEG (actual PEG) you need to download one of the versions with the PEG changes: https://github.com/lamont-granquist/MechJeb2/releases

- In real life NASA and Russian agencies had full blown trajectory optimizers so that the pitch programs they fed into their boosters put the rocket on a course where closed-loop guidance was guaranteed to pick it up and work.  If they had guessed at a bad pitch program like KSP players do, then their rockets would have flown equally as bad.

- I don't find it a compelling programming problem, or even a compelling historical problem to have old versions of guidance.  In reality the old Atlas-Centaur guidance, and Saturn IGM and Shuttle PEG were all informed by better trajectory analysis on the ground and therefore performed vastly better than what we can get out of them with no help.  So, no, I've entirely abandoned Atlas-Centaur guidance and mostly abandoned PEG as well (I'm still keeping it up to day with current MJ-dev).  The problem is that people ask "can it do this?  can it do that?" and the answer for PEG in a lot of cases is that it can't.  So I'm going to build guidance that can.  If that means that it generates the flip problem that you get ahistorically high guidance accuracy I don't have the time or interest in caring about that problem.

And no logs won't help, there's not going to be anything in the logs and the solution to problems with Atlas-Centaur guidance is to use PEG.

 

So, this is not a Mechjeb software bug, as such, but rather a realistic limitation of the actual algorithm? In other words, the guidance algorithm does not know, how to get to orbit from that set of starting conditions, and it will work, if brought closer to a working solution? Is that what you are saying?

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On 10/23/2018 at 4:48 AM, Kitspace said:

So, this is not a Mechjeb software bug, as such, but rather a realistic limitation of the actual algorithm? In other words, the guidance algorithm does not know, how to get to orbit from that set of starting conditions, and it will work, if brought closer to a working solution? Is that what you are saying?

Correct.

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@Jim DiGriz okay, I also had the idea, but it was very very tight - you cannot assume that the orientation is still perfectly fit to the node after timewarping ...

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1 minute ago, Gordon Dry said:

@Jim DiGriz okay, I also had the idea, but it was very very tight - you cannot assume that the orientation is still perfectly fit to the node after timewarping ...

It doesn't.  There's some additional time added to pre-burn for slewing.  It also doesn't ignite until it is aligned with the node.

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Does anyone have a download for the alternative modules like the TomTom ? the download links does not work anymore and I've accidentally deleted the file ...:/

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4 hours ago, matts73 said:

Does anyone have a download for the alternative modules like the TomTom ? the download links does not work anymore and I've accidentally deleted the file ...:/

 

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As many have said before, life without MechJeb would not be nearly so nice, so thanks @Sarbian for maintaining this mod...

I do have a couple requests if you're in for that sort of thing:

1 - Could there be an indicator on the maneuver planner window to show if MechJeb is currently executing the next maneuver node or all maneuver nodes?

2 - When MechJeb is executing the current maneuver node and it encounters another maneuver node that begins before the currently executing node ends, it appears that the remainder of the first burn is lost or the burn is marked completed and MechJeb moves directly into executing the second node.  Would it be possible to modify this behavior so that if a second node is encountered before the first is completed, MJ would continue executing the first to completion or possibly even combine the two maneuvers?

 

Thanks,

Danny

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Hey, guys...
I LOVED the update and the changes you´ve done to the KSP 1.5.1 compatibility. Most of all, those little changes on the maneuver planner. Great!
Thank you for the efforts!

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Is there a way to have MJ simultaneously circularize and change inclination together?

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50 minutes ago, dlrk said:

Is there a way to have MJ simultaneously circularize and change inclination together?

No, with the Maneuver Planner it's always separate maneuvers. Personally I don't try to use MechJeb for complex orbital maneuvers that are trying to combine multiple orbital changes like this. I do it by hand with the stock maneuver node tool and save MechJeb for the routine maneuvers.

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5 hours ago, dlrk said:

Is there a way to have MJ simultaneously circularize and change inclination together?

Sorta.

You can combine two maneuvers if one of them can be made to happen "at a specific time". So circularization works for that. So, set up the plane inclination how you want. Then use the maneuver planner to create a new maneuver to circularize at a fixed time of t=0 seconds after the last node. Then you go to the maneuver editor, and it should have "merge with next node" button. Click that and it will combine the two nodes.

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I've been playing around a bit with the new bi-impulse transfer function, and it would be nice if there was an option for the old Hohmann transfer functionality as well. Sometimes, a three-burn solution is just better. To give a concrete example, I tried a fairly standard Kerbin->Minmus transfer just now. With the 3-burn system, you do a ~920 m/s initial burn, then a plane change somewhere along the way (usually about 10 or so m/s, though it varies) and then the capture burn. With the bi-impulse, it was giving me a transfer burn of ~11-1200 m/s (using the "optimum time" setting). It was also picking a decidedly higher-energy transfer, taking maybe 6 days to reach Minmus, and hence needing a bigger capture burn as well. In all, I'd estimate it was giving a solution that was maybe 300 m/s less efficient than the previous setup, so call it 25% more dV

I assume that it's a combination of the higher dv cost of low-altitude plane changes (even when combined with the big prograde burn) and more importantly the solver getting stuck in a local minimum in parameter space. The latter is a Hard Problem to solve (I deal with nonlinear optimizers from time to time in my day job, so I'm very sympathetic to the difficulty), so being able to fall back to a numerically-simpler algorithm might not be a bad idea. 

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9 hours ago, dlrk said:

Is there a way to have MJ simultaneously circularize and change inclination together?

Look at the very nice precise maneuver mod. (The mod author has computer issues that have kept him from updating the compatibility test, so it poodlees about not being compatible with 1.5.1, but it really is). Create the circularization mods with MJ; then the precise maneuver node editor will open up and allow you to easily add a plane change.

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