Manouver Target node goes haywire... (MJ?)

[renejant]

I recently read someone's thread about the Manouver Target node going haywire while mechjeb tries to turn towards it... I've searched the forums but i can't seem to find that specific thread...

Yesterday I've launched a small ship into orbit using mechjeb 2.4.2, after reaching orbit i finetune the orbit to be more precise (align planes, inclination etc.) but when you've set up the node and mj almost reaches it. the node starts to move all over the navball which makes it impossible to reach it and so finalizing your manouver...

Is there a fix for this? Cause its quite annoying to keep adjusting it over and over again... It doesn't happen all the time, but certainly most of the times... Now i am also wondering if this is a MJ related "bug" or just a "bug"with the game itself?

If there's a fix for this, can someone point me into the right direction in fixing this?

[smjjames]

I've noticed this when the maneuver node delta v is tiny, and is often exacerbated when you have a heavy ship. I think it may be a combination of floating point error and other things.

maybe try the latest dev version? Or dev version #401 since 402 seemed a bit unstable to me.

[renejant]

Might give that a try... Im using MJ 2.4.2 stable release for now.... It doesn't give me much trouble, only the above specified problem i have been encountered so far... But im still wondering if this is related to MJ or not...

Going to try and set up the manouver nodes myself and let MJ handle them... lets see what that gives me...

[biohazard15]

It usually means that you have some problems with attitude-keeping. Mostly it manifests in large, non-symmetrical or overpowered ships.

You might wish to set "Tolerance" parameter in maneuver planner to 3-4 m\s. There is no tolerance option for ascent guidance, but you might wish to use throttle and\or acceleration limiters.

[renejant]

I have set my tolerance parameter set to 0. as standard... might that be the case? And i usely set my throttle limit to 10 or 25% Have to try it out and see what it gives me... Didn't knew that tolerance would affect to the manouver node so much????

[smjjames]

You mean 0.1? Because that's the default.

i haven't had the problem with the maneuver node on ascent, but I have had it when the delta v is in the tenths (as in 0.#) and the ship is heavy and/or slow to turn.

[biohazard15]

You mean 0.1? Because that's the default.

i haven't had the problem with the maneuver node on ascent, but I have had it when the delta v is in the tenths (as in 0.#) and the ship is heavy and/or slow to turn.

Yeah, that's what I mean.

Think of it as a dumptruck which tries to park between two other trucks - with a clearance of about twenty centimeters. Can it be done? Yes, but you'll need a really experienced driver. MJ is not an experienced driver.

Add some RCS and reaction wheels on your ship in order to keep its attitude.

[renejant]

I've tried the suggestions of smjjames and biohazard15 and im using the dev version of mj 401.... All these have worked so far, my manouver node is less wobbly now i can be more accurate with my docking attemps....

It seems that with using a tolerance of 3 m/s the ship seems to be more accurate... its still abit wobbly with the node, but alot less than it used to be... i thank you guys for guiding me into the right direction... still, i think this needs more attention as to how to pinpoint the specific problem...

It's on the manouver planner that i have found this kind of problem... dunno if im doing something wrong or that it is a specific problem with mj.... however every bit of help, helps me into the right direction into pinpointing the problem at hand...