sarbian

Optional MechJeb Modules for FAR, NEAR & km_Gimbal 2/3 (July 16)

Recommended Posts

does this work with near? Mechjeb cannot control anything in atmosphere with NEAR istalled.

For everyone worried about NEAR support with MechJeb... just pick a better ascent profile and make sure your launch TWR is ~1.20 by using the thrust limiters. Pretend you're all rocket scientists!

I get solid launches (with MechJeb and NEAR) when I have a solid rocket design. General parameters are as follows:

Orbit Altitude: 100km

Gravity turn start: ~0.5km

Turn shape: ~66%

Turn complete altitude: ~45km

You'll notice (weirdly!) that these are much more realistic launch parameters than what stock KSP favors. You don't even need control surfaces or RCS if you set up your launch correctly.

Capture.JPG

Capture2.JPG

EDIT: That being said... I WOULD like to see "limit to terminal velocity" work in MechJeb with NEAR... especially in non-Kerbin atmospheres.

Edited by FlexGunship

Share this post


Link to post
Share on other sites

I haven't had quite that setup work well for assent settings, but do totally agree just experiment with the parameters for a profit that works best. Have not had any problems at all with NEAR and MJ for launch. :)

Possible weird problem with landing where the landing system won't work if the TWR is between 1.00 and about 1.8. Lower and higher works fine but between then the landing system doesn't want to aim. Not sure if it's really because of NEAR though as the same issue occurs on moons without an atmosphere.

Share this post


Link to post
Share on other sites
For everyone worried about NEAR support with MechJeb... just pick a better ascent profile and make sure your launch TWR is ~1.20 by using the thrust limiters. Pretend you're all rocket scientists!

EDIT: That being said... I WOULD like to see "limit to terminal velocity" work in MechJeb with NEAR... especially in non-Kerbin atmospheres.

Im talking about spaceplanes, rockets are fine. When I use spaceplane guideance

a) it cant land and when I enable autoland it makes my ship oscillate all over the place

B) when i try to make it hold my current heading +/- a few degreees and my altitude +/- a few hundred m it does the same thing. very annoying.

Share this post


Link to post
Share on other sites
Im talking about spaceplanes, rockets are fine. When I use spaceplane guideance

a) it cant land and when I enable autoland it makes my ship oscillate all over the place

B) when i try to make it hold my current heading +/- a few degreees and my altitude +/- a few hundred m it does the same thing. very annoying.

Understood, my apologies.

Share this post


Link to post
Share on other sites

I uploaded a new version of MechJebFARExt.

- should not trigger part failures due to aerodynamic stresses anymore

- report better info to MJ when you disable pitch/roll/yaw on a surface control

- use a bit less CPU

Share this post


Link to post
Share on other sites

And I added MechJebNEARExt for NEAR support inside MJ.

Share this post


Link to post
Share on other sites
I uploaded a new version of MechJebFARExt.

- should not trigger part failures due to aerodynamic stresses anymore

- report better info to MJ when you disable pitch/roll/yaw on a surface control

- use a bit less CPU

I was just about to post a bug report when I saw this post. I was having a problem where control surfaces on my spaceplanes would detach if I switched vessels in orbit and switched back to the plane. If I understand correctly, this fixes that problem? I really like how stable the plugin makes my space plane launches, but I've had to send two rescue missions to retrieve crew from derelict planes and since removed the plugin. If that's fixed, I'll be reinstalling ASAP. Just wanted to make sure.

Share this post


Link to post
Share on other sites

Yes, it fixes that.

Share this post


Link to post
Share on other sites
I was just about to post a bug report when I saw this post. I was having a problem where control surfaces on my spaceplanes would detach if I switched vessels in orbit and switched back to the plane. If I understand correctly, this fixes that problem? I really like how stable the plugin makes my space plane launches, but I've had to send two rescue missions to retrieve crew from derelict planes and since removed the plugin. If that's fixed, I'll be reinstalling ASAP. Just wanted to make sure.

Hilarious! That's exactly my story too. :) Looking forward to trying out the FAR extension again with that fix. :)

Share this post


Link to post
Share on other sites

Just add the EXT to the mechjeb folder and keep both dll or do i need to replace them?

Share this post


Link to post
Share on other sites
Just add the EXT to the mechjeb folder and keep both dll or do i need to replace them?

Since he said that it is intended to be used with the newest mechjeb dev version, and that the two part .cfg files have not changed in a long time, and in particular that the EXT is about 1/10 the size of the mechjeb2.dll, it seems most likely that they are intended to be both present at once (I had the same question, and that was the though that I thought).

Share this post


Link to post
Share on other sites
Since he said that it is intended to be used with the newest mechjeb dev version, and that the two part .cfg files have not changed in a long time, and in particular that the EXT is about 1/10 the size of the mechjeb2.dll, it seems most likely that they are intended to be both present at once (I had the same question, and that was the though that I thought).

Yea figured it out with the proverbial "Trial by fire" and threw it all in and loaded KSP, all was fine.

Share this post


Link to post
Share on other sites
And I added MechJebNEARExt for NEAR support inside MJ.

This is brilliant! Thanks.

...now to cautiously transition from praise to a request...

I would love it dearly if the "limit to terminal velocity" function worked with FAR and/or NEAR. Are there any plans to incorporate that piece?

Share this post


Link to post
Share on other sites

Why ever would you need it? Unless you have a liftoff TWR of 4 or so and you make a very shallow ascent, it's not relevant.

Share this post


Link to post
Share on other sites

Mechjeb is reporting thrust (and acceleration) that is significantly less than actual. This is occuring on all engines - for example, the KW Griffon 8D, with ~1641 KN of thrust at sea level (I use KIDS) (obtained from right-click menu on that engine) - mechjeb reports ~410 KN of thrust, and an acceleration of ~2.9 m/s^2. As my ship is moving upwards rapidly from Kerbin's surface, this is clearly in error. Is there a possible mod conflict here? or might I have some other issue?

EDIT: this is using the 309 dev release.

Edited by ABZB

Share this post


Link to post
Share on other sites
Why ever would you need it? Unless you have a liftoff TWR of 4 or so and you make a very shallow ascent, it's not relevant.

It's handy to "automatically" throttle a main engine after SRBs are exhausted. I totally understand what you're saying; proper use of thrust limiters can balance stages for the most part. But for SRB heavy launches it's helpful... you don't have to adjust the thrust limited mid-ascent.

I feel like, with MechJeb and NEAR (or FAR), if you design your rocket well, it shouldn't require any input between launch and stable orbit. This is the only piece missing for me.

Share this post


Link to post
Share on other sites

No, what he is telling you is that hitting the terminal velocity with FAR or NEAR require ridiculously overpowered rockets.

ABZB : I'll have a look but why did you report it here ? it's a pure MJ problem not related to the ext.

Share this post


Link to post
Share on other sites

My bad, then - this started after I updated the ext (and updated to the latest dev version) - I had initially assumed it was an issue with the ext. on further copy/pasting versions around, it is not due to the ext (still happens with that removed) and is present for me in the previous two dev releases (308 and 309).

Share this post


Link to post
Share on other sites

I gave this a try and it seems to be working ok. Ascent guidance is a lot smoother with km_Gimbal loaded, thanks Sarbian.

Share this post


Link to post
Share on other sites
No, what he is telling you is that hitting the terminal velocity with FAR or NEAR require ridiculously overpowered rockets.

Fair enough, you guys know better than I do. Capsule drop shows about 120 m/s below 1km. And about 250 m/s at 3.5km. Maybe it's not a good test; but these numbers aren't impossible to hit at a TWR of ~1.5. Especially if you start your gravity turn early.

Share this post


Link to post
Share on other sites

"Capsule drop"

Which your rockets are shaped nothing like. Let's recall that FAR and NEAR are *all about* having shape *matter*.

Share this post


Link to post
Share on other sites

I fixed an error in MechJebKMGimbalExt so you should update it ( and MJ since an similar error was fixed )

Share this post


Link to post
Share on other sites

What are the actual parameters of this support? Is it just Ascent Guidance, or Landing Guidance and Spaceplane Guidance too?

Share this post


Link to post
Share on other sites

Hello.

I am using Ferram aerospace research and Realism overhaul and there is a problem of some sort with them.

The problem is that at pretty high speeds at some point into the flight Mechjeb is suddenly starting to use extrmely agressive control inputs where no inputs at all would still do good and finally makes a firm and stable rocket wobble like crazy and maybe even fall apart even with the modules from here installed.

It will happen to basicly any vehicle no matter how stable it is and how much control authority does it have.

Thank you.

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.