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

[Soviet borris]

this is a truly excellent mod

[maro]

Unless I'm missing something it isn't possible to change orbital inclination using mechjeb right? Is that something that could be added?

Use NML+ or NML- form the Smart A.S.S. option will alter your inclination

[Nori]

Use NML+ or NML- form the Smart A.S.S. option will alter your inclination

That just points you in a direction right? So I guess I'll still have to do some work in applying the proper thrust.

[maro]

That just points you in a direction right? So I guess I'll still have to do some work in applying the proper thrust.

Look a the orbital Information Panel at "Inclination" - during you fire the engines this number you have to look at.

[[email protected]]

I\'m still getting a 'This part type isn\'t available in this version of KSP' error even when using MechJeb version 1.9 with KSP 0.16.

I got this problem too. One reason for it is because the plugin can't be loaded because it was blocked. If you're in windows, right click > properties > unblock > apply, should fix it

[Nuke]

Unless I'm missing something it isn't possible to change orbital inclination using mechjeb right? Is that something that could be added?

antinormal at the ascending node or normal at the descenting node, i think. i usually eyeball the maneuver by looking at the target orbit edge on, and wait till your current orbit crosses it, and then burn normal or antinormal until the two orbits look like they are in the same plane. i learned this playing orbiter really the orbiter manuals are a must read because it pretty much breaks down all your basic flight maneuvers. ksp makes it a lot easier with its 3d orbital view though.

Edited August 27, 2012 by Nuke

[Nori]

Look a the orbital Information Panel at "Inclination" - during you fire the engines this number you have to look at.

But but, it's not automagical! I mean how can you expect mere Kerbals to multitask like this?

Anywho, thanks for the advice. I really want to perform a rendezvous (for orbital mechanic) but I always seem to get screwed up inclinations..

[Nuke]

But but, it's not automagical! I mean how can you expect mere Kerbals to multitask like this?

Anywho, thanks for the advice. I really want to perform a rendezvous (for orbital mechanic) but I always seem to get screwed up inclinations..

those are fun. this is actually one of the things i never figured out when playing orbiter, as it had a pretty decent rendezvous gauge. i had to play ksp to figure out how to do it bny eyeball

step 1: align planes (use procedure in my last post for this), be extremely precise.

step 2: burn prograde/retrograde to move periapsis toward the target orbit till they touch (crossing it a little doesn't hurt). it doesn't really matter where in the orbit this is done.

step 3: at periapsis burn pro/retro to bring the apoapsis closer to the orbit, not all the way.

step 4: warp time till you have a close encounter with the target. should be a few degrees or less of a difference.

after that it gets trickey. with the orbits on the same plane the problem is a 2d problem. so you have 4 possible manuvers, prograde burn, retrograde burn, and +/-rad burns, these will all be smallish maneuvers. essentially you want to match velocity with the target, plus or minus what is needed catch up to the target or let the target catch up to you. once that is done then match speed with the target. you should then be close enough to do an approach. its fairly easy to transfer kerbals via eva at ranges of about 3km, i did a 5 km crew transfer with a little bit of overshoot. doing it with a whole ship is harder, but possible.

if you are behind the target, and your velocity is less than the target, burn prograde until your velocity is slightly higher than the target's velocity, when you pass the target you will want to then match speed as close as possible. if youre behind and velocity is more, then you are ok, just wait till pass it and match speed. if you are ahead of the target, and your velocity is more than the target, burn retrograde to drop your velocity slightly below the targets velocity, allowing it to catch up, and if the velocity already slower, you just need to wait for it to catch up. if you get a lot of yoyo try reducing the velocity difference during catch up-fall back maneuvers (i find a difference between 20 and 50 km/sec work fine).

while you are doing that there is another thing to worry about. you need to keep an eye on whether or not your orbits are converging or diverging, if they are converging yay, you are doing it right. now if you are diverging you need to fix that. ive actually found that burning along your orbits radius (+/- rad) can tweak your trajectory. out diverges your orbit away from the gravity source, and down diverges it towards it. you will have to do this alot.

eventually you will get within a few km of the target, and can approach visually. kill your rotation and try to gauge the horizontal and vertical motion of the object in your view. make appropriate burns to make that motion stop. while making sure the distance counter is counting down, but not too fast. its fun to practice with kerbals, as they can move fairly easy and can grab on to ladders.

[Nori]

Thanks for that information. It'd be great to see stuff like that on the wiki.

[FishyFishy13]

Are you planning on making a fully automated rendezvous system? It's the one operation in ksp that I can never perfect I get so close and I still manage to over Shoot my target every time.

[Turnip199]

Apparently, when you decouple a MechJeb controlled probe/satellite from above the ship makes it uncontrollable by the module. Has anyone else come upon this problem or is it just localized to the setup of my probe?

[Ekku Zakku]

It's a known bug, it's known though and so it should be fixed in the next version (I hope). But it could also be the game, because my Escape Pod SAS also does this. I think it's just something to do with controlling separated parts.

[Colderjake1524]

i would trust mechjebs landing autopilot over my own landings any day.

[MrMoog]

i would trust mechjebs landing autopilot over my own landings any day.

I don't care too much about landing, as long as I have some fuel to spare! But the auto-ascent feature is a godsend for huge rockets that want to eat my CPU and let me with 1fps or less on lift off.

[Colderjake1524]

I was flying the Eagle I from another mod and it works perfectly with the main engine, if I use its VTOL engines it goes crazy.

[Nuke]

yea until you land something like this monstrosity. mechjeb only gets it right 1/3 of the time.

[Colderjake1524]

yea until you land something like this monstrosity. mechjeb only gets it right 1/3 of the time.

That is just huge.

[Nuke]

it has no re-launch capability. its kind of a moon base with room for 28 kerbals.

[Colderjake1524]

I forget to take pictures of my launches. I guess I will start taking more.

[Colderjake1524]

This is what I have been flying for the past 10 minutes

[ptaylor25]

This is what I have been flying for the past 10 minutes

Space 1999 flashback

[Colderjake1524]

Yep, it works perfectly with the mechjeb

[eoosting]

I am curious if the mecjeb developers have considered implementing something like a "flight director" function. For those unfamiliar, in an aircraft a flight director is essentially a display of the control inputs required to maintain the desired attitude, while not actually (or perhaps not necessarily) taking control of the flight controls. So I'm imagining that mecjeb would indicate to the pilot what control inputs, direction, throttle settings would be commanded by the mecjeb were it set in "auto pilot" mode vs "flight director" mode.

This could be an excellent learning tool for pilots or those that just want help flying without the full auto-pilot.

Thoughts?

[Nuke]

i think the big issue with landing huge payloads is rotational overshoot. i dont think mechjeb is accounting for the time it takes to change a massive ship's orientation, and as a result misses time critical burns. ive seen some ships where it can never seem to get into the right orientation at all. it would get close but because of the angular momentum and the time neccisary to stop it would be impossible to stop in time, and so the ship spins in circles just before it hits the ground at high velocity. thats my theory anyway. ive been able to get around it somewhat with about 3 dozen rcs thrusters, and no fewer than 5 1-meter rcs tanks.

its also likely my fault as the 19-engine coupler (my part by the way) im using hasn't been thorough balanced yet. after i landed that base i realized that the weight for the part was 32 tonnes (x2). considering it does hold a large amount of fuel that seemed appropriate. but ive seen other parts with bigger volume and lower mass, so i halved both mass and fuel capacity and it works better now (i wasnt using all the fuel anyway, that ship is loaded). i need to find some better balance guidelines.

for reference this is the stack i launched it on. this is however the motorcade version used to land all the rovers. the base launcher used the same descent tower and the same launch vehicle though, the only difference is the decoupler arrangement and the fact that the lower 19-coupler was hard attached to the launcher and the decouplers attatched right under the carts instead, and this provided slightly more fuel to the main engine which i believe was one of the 3 meter engines from novapunch.

mechjeb could launch the thing if you set the target apoapsis high enough and tweaked the launch profile curve to get the ship all the way out of the atmo before doing the gravity turn. otherwise the ship would topple and explode. though it does have the delta-v neccisary to do a flat trajectory transfer to mun. should try that one day.

Edited August 29, 2012 by Nuke

[lstutzman]

Probably the wrong place, but anyway. The stats windows (orbital, surface, vehicle, ascend), show awesome info, but with all of them active they take up a lot of screen real estate. In the same way that the logistics plugins stream out the info on a Tcp port, could MechJeb output the stats as well? This would allow me to write a client running outside of KSP to display/compare/graph the stats, while giving me back more of the screen in KSP itself. I would be able to have the client run on a seperate monitor, or even a seperate machine.