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

[Tassyr]

Yeah, I got a bug to report with Mechjeb 2. Sometimes when I ask it to land it'll engage the engine as if it's doing the deorbit burn, then start to rotate faster and faster until it's wasted all my fuel and the ship is spinning like a dang top. EVEN with RCS on- it just refuses to fire the RCS thrusters and spins like a top. This only seems to work with 'land at target' though. "Land somewhere" seems to work fine.

Advice?

[johnnyhandsome]

Stupid question, how do you upgrade to MechJeb2? I tried replacing the relevant parts and it wiped out ships using the plugin. Should delete the old Parts and Plugins and replace with new ones and everything should be fine?

[HGGundamReviews]

Stupid question, how do you upgrade to MechJeb2? I tried replacing the relevant parts and it wiped out ships using the plugin. Should delete the old Parts and Plugins and replace with new ones and everything should be fine?

For any ship currently flying you have to edit the presistance file and you will need to edit the Craft file as well to replace MJ 1.9.8 with MJ 2. Either that or delete the flying ships and launch new ones with MJ 2 parts instead of MJ 1, keep the MJ 1 installed until you have done one of these two things or it will cause you to lose ships and craft files because without the parts in the inventory they won't load in the VAB and SPH.

[COL.Neville]

problems that ive been running into consistently are

once it finishes a maneuver it wont return to its previous state. ie prograde is selected maneuver node completes it just spins wildly instead of going back to prograde.

the warp helper warp to SOI it will goto the SOI and just keep right on going to the next SOI change.

return from moon seems to send you off 180 degrees from where you should be going.

the transfer to another planet waits for years on a launch window in orbit instead of waiting on the Launchpad for days.

launch to rendezvous misses by a lot.

target rendezvous autopilot will run you directly thru the target instead of next to behind or above.

198 would do a 100x100x0 orbit everytime every rocket. mechjeb2 3 in 10 launches actually wind up where you told it to be.

okay what it does right.

it does look prettier.

[Lillz]

What Happens? - Ascent works as normal, reaches desired height, makes node to circularize. However, It will start the burn early AND not use a corrective angle to prevent losing altitude after you pass the apoapsis. Never had a problem with this before in mechjeb, but now I do.

[The_Duck]

What Happens? - Ascent works as normal, reaches desired height, makes node to circularize. However, It will start the burn early AND not use a corrective angle to prevent losing altitude after you pass the apoapsis. Never had a problem with this before in mechjeb, but now I do.

This is how it is supposed to work in MJ 2. MJ 1 would angle up to maintain altitude after reaching apoapsis. MJ 2 uses a different strategy where it always burns toward the maneuver node it creates, but tries to time the start of the burn so as to end up in a good circular orbit. The hope is that this reduces some problems the old strategy had with vessels with low TWR or poor attitude control authority. The new strategy does result in a slightly less circular orbit, but it should still be quite circular, and if you need precision you can use the maneuver planner to circularize precisely once in orbit.

Are you ending up with a bad final orbit? If so, if you give us the .craft file we'll try it out and see what's going wrong.

[tek_604]

once it finishes a maneuver it wont return to its previous state. ie prograde is selected maneuver node completes it just spins wildly instead of going back to prograde.

I've noticed this, but never really worried about it. I just press "T" to activate SAS, and then worry about my next move.

the warp helper warp to SOI it will goto the SOI and just keep right on going to the next SOI change.

I had this happen ONCE to me today, when trying to enter Minmus orbit. Wasn't really MJ's fault at this point, cause the Hohemann transfer was bad, and I wasn't paying attention. Still, I managed to recover it. I'd suggest keeping your mouse over the Abort button.

the transfer to another planet waits for years on a launch window in orbit instead of waiting on the Launchpad for days.

This is why I've given up on MJ for planet transfer. Try Protractor. I've been using it this weekend, and EVERY mission I have launched so far (Dres, Ike (via Duna), Gilly (via Eve) & Eve), Protractor never failed to get me on course. As soon as out of Kerbin SOI, I would then use MJ to fine tune the encounter.

I'd suggest somehow merging what Protractor does into MJ. Although it would mean I'd have to stop making the interplanetary burn manually, and I've actually been enjoying it

launch to rendezvous misses by a lot.

I find launch to rendezvous is difficult to use. When you go to map, and select the already orbiting vessel, it doesn't enter it into the MJ window, replacing it with some angle. Little bit confusing.

But, I don't expect the launch to put me right next to my target, just in the general area. From there, you can either dock direct (never tried this myself, and it would probably murder your mono consumption), or, you can use the Rendezvous Guidance to target. This is awesome to watch, and usually puts you in 50m or less of your target.

198 would do a 100x100x0 orbit everytime every rocket. mechjeb2 3 in 10 launches actually wind up where you told it to be.

I've noticed some difficulty with getting some rockets into 100x100. Usually, this is because the payload is too small compared to the rocket you've used. Also, if you have not enough torque to turn your rocket, this causes MJ problems, but then again, it would cause you problems if you tried to fly it manually

okay what it does right.

it does look prettier.

Bit unfair. I've had so much success this weekend with Protractor for planetary transfer, and MJ for everything else. This time last week, I thought my rockets were not powerful enough, and I wasn't getting enough Delta V to orbit. This weekend, turns out actually everything was fine, and every inner planet (Eve to Dres) I can reach easily with at least 1000m/s to spare.

Except Moho. Except Moho. The area between Moho and Eve is now littered with probes out of fuel

[COL.Neville]

yeah that's what im using is protractor and then use mj for the snuggle up next to the body. that angle is the launch/lead phase angle and ive noticed that if you subtract 10 from whatever it puts in there it gets closer but its supposed to be storing the performance data for your rocket and should know how long it takes to make the same ap as the target.

Even if you target and want to rendezvous with the target because I used the launch to rendezvous button its still using the altitude limits in the ascent guidance box instead of the altitude of the target.

yeah the prettier thing might have been a tad harsh. but instead of littering the screen with stuff that doesn't work how about just focus on making the basics work you know like it used to.

[Deltac]

This post was deleted. please bring back deleting...

[AndreyATGB]

Maybe it's been posted before, but why has the "Current TWR" been removed from MechJeb 2? I found it useful in 1.9.

[COL.Neville]

if im not mistaken the twr displayed is the current twr. ive noticed it changing as the rocket sheds stages, srb's etc.

[planetx]

This is how it is supposed to work in MJ 2. MJ 1 would angle up to maintain altitude after reaching apoapsis. MJ 2 uses a different strategy where it always burns toward the maneuver node it creates, but tries to time the start of the burn so as to end up in a good circular orbit. The hope is that this reduces some problems the old strategy had with vessels with low TWR or poor attitude control authority. The new strategy does result in a slightly less circular orbit, but it should still be quite circular, and if you need precision you can use the maneuver planner to circularize precisely once in orbit.

Are you ending up with a bad final orbit? If so, if you give us the .craft file we'll try it out and see what's going wrong.

What MJ2 does is how it should be:

It halves the calculated burn time and burns each 50% on each half of the maneuver node. So if the burn time for a maneuver is 60 seconds, it will start the burn 30 seconds before the maneuver. It's the most accurate way to burn a maneuver node. MJ1 had its own unique method of circularizing, but since MJ2 uses maneuver nodes that's what makes it "burn differently" but you still end up with a good result.

[nuclearace]

I'm running MJ 2.0.7 and I'm having a problem where when I create a 'transfer to another planet node' whenever the spacecraft begins to orient to the node the required D/v goes through roof. Say if it was 800 m/s before I execute the node it sometimes jumps to 3000 m/s. It's done this even when there were only a few days to the node. The only solution I've found is to orient to the node, then cancel it, and then make a new node and hope that I can maneuver to the node without messing up the d/v.

[AndreyATGB]

if im not mistaken the twr displayed is the current twr. ive noticed it changing as the rocket sheds stages, srb's etc.

It isn't. It's changing because you're using up fuel, reducing the mass and thus increasing the thrust available but it's still only valid for the surface.

[The_Duck]

Maybe it's been posted before, but why has the "Current TWR" been removed from MechJeb 2? I found it useful in 1.9.

We can certainly add it back as a custom window item if it's useful.

I'm running MJ 2.0.7 and I'm having a problem where when I create a 'transfer to another planet node' whenever the spacecraft begins to orient to the node the required D/v goes through roof. Say if it was 800 m/s before I execute the node it sometimes jumps to 3000 m/s. It's done this even when there were only a few days to the node. The only solution I've found is to orient to the node, then cancel it, and then make a new node and hope that I can maneuver to the node without messing up the d/v.

This sounds like it's somehow caused by physics jitter/numerical precision errors in KSP. Is your orbit perhaps very circular when this happens, so that the Ap and Pe markers on the map view go crazy? I'm not sure how exactly this could cause problems, but I could imagine some connection.

When the dV gets messed up, what happens to the predicted trajectory after the node? Does it still look reasonable or is it perhaps pointing off in the wrong direction?

[IlludiumQ36]

Smart ASS is completely disabling my keyboard when using surface (SUR?) controls (set heading and pitch). I can't manually stage or change throttle or anything - can't even pause the game with ESC. If I close the Smart ASS window or switch to ORB or TGT, keyboard control is restored. What is the issue with that?

[The_Duck]

Smart ASS is completely disabling my keyboard when using surface (SUR?) controls (set heading and pitch). I can't manually stage or change throttle or anything - can't even pause the game with ESC. If I close the Smart ASS window or switch to ORB or TGT, keyboard control is restored. What is the issue with that?

Perhaps one of the input text fields has keyboard focus? When this happens, try clicking somewhere on the scene outside the Smart ASS window to give keyboard focus back to the game.

[welshboy]

Smart ASS is completely disabling my keyboard when using surface (SUR?) controls (set heading and pitch). I can't manually stage or change throttle or anything - can't even pause the game with ESC. If I close the Smart ASS window or switch to ORB or TGT, keyboard control is restored. What is the issue with that?

I have noticed this too when using various options not just the Smart ASS . It does not do it all the time at least that I can remember but I have had it happen using the rendezvous module.

From 1 example that I remember , I would be on the map screen and activated rendezvous and the not being able to get out of map view to make sure I was not going to collide with my space station , could not press esc or anything else until de-activating the module.

Oh and this is with the 2.0.7 version

[Payload]

Perhaps one of the input text fields has keyboard focus? When this happens, try clicking somewhere on the scene outside the Smart ASS window to give keyboard focus back to the game.

OMG THIS! It's the most annoying thing ever. This has caused me many harsh failures.

[Malachai]

Quick question: can Mechjeb (either 1.9.8 or the prerelease) handle landings when the cockpit/drone core is horizontally oriented, or will it only land at 180 degrees?

And if this question has been asked, forgive me. I did a quick search, and I didn't find anything relevant. And reading through 130 pages isn't something I want to do.

[goldenpeach]

I have a suggestion:

First of all,I know that MJ 2 bring a new ascent mode.I know that the new ascent mode is better for ships that have low TWR and/or low control.

However, the ascent mode of MJ 1 was making more circular orbits than thew ascent mode of MJ 2.

My suggestion is not the keep the ascent mode of MJ 1 and throw away the ascent mode of MJ 2 but to have both of them.

In the ascent guidance options,you could be able to choose between the two ascent mode which will allow very circular orbits to rockets whit a high TWR and control and in the same time it will allow a less circular(but still very good) orbit to the others rockets.

Thank you for reading and sorry if it has already been suggested.

EDIT:I just wished to say that the new version is very good and that I like the new option it offer.(I know that it has already been told many time and it is not original at all...)

Edited May 7, 2013 by goldenpeach

[planetx]

I'm running MJ 2.0.7. I've been having issues with MJ auto-staging even though auto-stage is turned off and even though I'm not even using ascent guidance.

Also I can usually create new stages on the fly while the ship is being flown but for some reason MJ keeps "auto-staging" and it just prevents me from doing that.

[sadron]

Which version should I use? 1.9.8 or 2.0.7?

[AndreyATGB]

Which version should I use? 1.9.8 or 2.0.7?

2.0.7 is better looking and does more stuff.

[Galantir]

I actually thought of something today, i'm not sure if it is mentioned somehwere already and i've missed it but...

In my opinion a combination of the RemoteTech addon and MechJeb would be awesome.

That way we would be able to control satelites and stuff remotely with MechJeb controls.