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MechJeb 2 - Patch test bed release (October 10)


sarbian

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Re: latest build dated 8-25-2013

Autopilot is NOT docking but it is doing a fantastic job of stationkeeping. There has literally been zero drift between the two ships for a solid hour and very little monoprop lost.

It did that to me only once and it was because I was playing with conserve RCS fuel and smart RCS translation maybe next time that happen u can try to toggle it to see if it helps. It is options u can add from custom menu thing.

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Well a while ago "Iannic-ann-od" posted a way of doing it in the Chatterer thread, and then posted it in the Addon requests and support forum http://forum.kerbalspaceprogram.com/showthread.php/46238-Movable-Screen-Icon

here is the what he wrote:

Chatterer icon relocation for reference or just take it and use it:



protected Rect ui_icon_pos;
private bool changing_icon_pos;

protected void draw_GUI()
{
//Icon relocation
if (changing_icon_pos == false)
{
if (GUILayout.Button("Change icon position")) changing_icon_pos = true;
}
else GUILayout.Label("Click anywhere to set new icon position");
}

public void Update()
{
//Icon relocation
if (changing_icon_pos && Input.GetMouseButtonDown(0))
{
ui_icon_pos = new Rect(Input.mousePosition.x - 15f, Screen.height - Input.mousePosition.y - 15f, 30f, 30f);
changing_icon_pos = false;
}
}

Maybe Sarbian might like to include this in Mechjeb :)

That would be nice but maybe it would be best to let the guy concentrate on fixing bugs.

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It did that to me only once and it was because I was playing with conserve RCS fuel and smart RCS translation maybe next time that happen u can try to toggle it to see if it helps. It is options u can add from custom menu thing.

Thanks, that did the trick. Fuel conservation threshold cannot be set to anything at all or you will not go to dock today. It didn't seem to care that rcs conservation was enabled at all, just that the threshold not be enabled.

It is now back to stock MJ docking behavior meaning that it refuses to move faster than 0.05ish but 0.05 is better than 0.0 (nothin' into nothin'... carry the nothin'...)

edit: and the counterfiring. O how it loves to counterfire. over. and. over... and over......

Edited by Starwaster
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I'm not using this patch so I guess I'm serving as a control in this experiment. IMHO the patch is not introducing any problems in docking because the issues are the same in stock MJ2.

The above behavior definitely happens in unpatched MJ2. I believe the cause is that you still have "control from here" set on the MJ part itself (which is where it defaults to when the ship spawns) instead of the docking port. If MJ is the "control from here" part, it will line itself up with the target docking port. Because it's stuck on the side of the ship, this causes the 1/2-off misalignment. Setting "control from here" to the docking port or any centrally placed command pod solves this problem, but it's a problem the patch should fix.

Unpatched MJ also has the problem a docking ship stopping indefinitely a short distance from the target. I don't know what causes this but there's an easy work-around. Disable the autopilot, tap RCS in any direction (but usually ahead is better), then reengage the autopilot. This seems to shake it out of whatever vapor lock it's gotten into.

Just to touch on this from my perspective, I don't use the MJ part and have not in quite some time. The MechJebCore module is built into all of my command modules and probe cores. I haven't had any problem (aside from MJ's standard docking flakiness) since I turned off RCS fuel conservation and conservation thresholds....

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This is kind of an old bug, I noticed it in MJ2 awhile ago, but never remembered to report it (just like I still haven't remembered to hack the hacked kerbals from the stupidity test out of my save, grrr.)

I've seen this twice, with the same basic setup: An 'inert' (no engines) probe on top of a 'lifter', with the MJ unit on the lifter. I Frequently end up with fuel left over in the last 'lifter' stage once I get to where I want to dump the probe at.

Trick being, when I dump the probe? The 'Lifter' loses the ability to calculate Delta-V. Turns into just NaN from then on. I suspect it has something to do with the probe having the root part, but I'm not sure.

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Would it be possible to make MechJeb work like TAC fuel balancer or chatterer where the module is always active and doesn't require a part? I know I could always edit the command pods to include the mechjeb module but that gets annoying every time there's a mod update and I prefer not to modify the stock part files.

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New version : 2.0.13243.0010

- deactivate ASAS when MJ take control

- Ascent AP : Turn start altitude can't be set to 0km

- Remove special case for ascent AP that may turn some ship too soon.

- Add some feedback for this special case

- Made BloodyRain2k Auto ascend params use clearer with a radio button to activate it

- Improved Docking AP - More agressive and does dock :)

- Fix Exception spam on "Suicide burn countdown" & "Time to impact"

- taniwha-qf #162 : MechJeb doesn't see in-flight docked fuel

The Ascent AP special case may be why some had their ship turning to circularize before they got out of atmo. I removed the special case but added a Text under the AP status. If you had the problem and you see "Early circularization" while testing please report it.

BloodyRain2k AP auto ascent param now use switch. Easier to understand. When active you have :

- Turn End Altitude is the larger of 85% of your orbit altitude / 30km / the atmo end if there is one

- Turn start is 10% of Turn End or 20m above the ship if there is no atmo

Docking should work better. At least it does for me. Setting the maximum speed is now recommended, unless you want to see some true Jeb piloting ( MJ2 could fly Docking AP twice as fast but I feel some margin would be useful )

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New version : 2.0.13243.0010

- deactivate ASAS when MJ take control

- Ascent AP : Turn start altitude can't be set to 0km

- Remove special case for ascent AP that may turn some ship too soon.

- Add some feedback for this special case

- Made BloodyRain2k Auto ascend params use clearer with a radio button to activate it

- Improved Docking AP - More agressive and does dock :)

- Fix Exception spam on "Suicide burn countdown" & "Time to impact"

- taniwha-qf #162 : MechJeb doesn't see in-flight docked fuel

The Ascent AP special case may be why some had their ship turning to circularize before they got out of atmo. I removed the special case but added a Text under the AP status. If you had the problem and you see "Early circularization" while testing please report it.

BloodyRain2k AP auto ascent param now use switch. Easier to understand. When active you have :

- Turn End Altitude is the larger of 85% of your orbit altitude / 30km / the atmo end if there is one

- Turn start is 10% of Turn End or 20m above the ship if there is no atmo

Docking should work better. At least it does for me. Setting the maximum speed is now recommended, unless you want to see some true Jeb piloting ( MJ2 could fly Docking AP twice as fast but I feel some margin would be useful )

Will it use less RCS fuel? I've got to the point that I have to turn on unlimited RCS every time I use autodocking and I hate doing that.

Would it be possible to make MechJeb work like TAC fuel balancer or chatterer where the module is always active and doesn't require a part? I know I could always edit the command pods to include the mechjeb module but that gets annoying every time there's a mod update and I prefer not to modify the stock part files.

ModuleManager. Every single one of my capsules and cores is MJ2 equipped and not a single one of their .cfg files edited.

Edited by Starwaster
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Will it use less RCS fuel? I've got to the point that I have to turn on unlimited RCS every time I use autodocking and I hate doing that.

I've given up on MechJeb's rendezvous and docking autopilots, they're completely hopeless in terms of fuel usage and time. These two procedures I do manually these days- specifically I'll use Smart A.S.S. and occasionally the maneuver planner rather than the autopilots.

The docking pilot has the right idea, but it needs to combine 'holding still in Z and moving towards docking axis' and 'moving in to dock' into a single mode, and that mode needs to have a narrowing tolerance window so that if you start it 200m out it allows itself to be really coarse with the adjustments as long as they're approximately ok (and thereby save a TON of mono), and become finer as it gets closer. Ideally it should have the two ports aligned and the relative motion vector parallel to the docking axis by about 10m out.

For visualisation purposes, envisage a curved horn or funnel coming to a ~1cm point 10m out from the target port. The docking pilot should use the minimum amount of RCS fuel to maintain appropriate forwards velocity while remaining within this shape.

A while ago I made a quicksave then let MechJeb's docking autopilot do the procedure. Came back in 15 minutes (yeah it takes aaages), and disgusted at it using 300 units of monoprop I did it myself. With 7 units of monoprop and about 5 minutes.

If I'm feeling lazy, I'll engage the docking autopilot then make judicious use of timewarp to prevent it constantly spamming RCS and shredding the monoprop.

The rendezvous autopilot should avoid the phasing orbit completely if a single burn could get an adequately close intercept. I've had numerous situations where I did one burn of ~30m/s to get my intercept within 2km then a tiny adjustment burn of maybe 4m/s to get it within 200m, where the rendezvous autopilot used a couple hundred m/s creating a phasing orbit then plotting an intercept from there.

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Wow, docking is massively different. Very little RCS usage that I see, but boy does it push that speed limit. I like it.

One problem I've found (but haven't narrowed down) is that if you're negative position relative to the docking vector (vector pointing outward from the target dock - toward where the active docking vessel will be) then the docking vessel appears to orient the right way, but thrust the wrong way - so it flies away from the target. If you get positive position relative, it works fine. I'm not sure precisely what the condition is that causes the problem, but it did it it twice to me and that appears to be when it happens. Essentially, I'm rotating my orbital boost stage 90 degrees and re-docking to the same craft.

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docking feedback: Wow. huge improvement. I do see some thruster usage that I consider unnecessary but since overall usage is hreatly reduced, it might be within acceptable limits to me. More research needed.

I've been wanting a more aggressive docking autopilot for awhile and now it's here. In fact it scared me to watch it in action. Might be best to have it back up a little more and it doesnt have necessarily have to face the dock to move away from it.

The circumstances under which I tested it were atypical however. In an actual docking scenario I would try to set the situation up better. the scenario I threw at it involved a slightly unbalanced RCS and I asked it to dock at a port 5 meters further 'up'. procedure was undock, set control from port, target other port, autodock.

AP backed away a little

Translated 'upwards' with 2 second burst while still backing away.

balance issue caused the nose to pitch down

MJ stopped thrust and reoriented to the port.

slowed craft

moved forward and docked.

I didnt realize it was a balance issue I was seeing at first because the craft is mostly balanced . It just looked like AP turned the pod to back up into the target port axis. I.E. it seemed deliberate but instead what happened was that as it lost port alignment it stopped RCS action and reoriented to the port. In short, it was a case where unbalanced RCS helped it dock even though it was unintentional.

advice to those trying this new docking AP, leave speed limit at 0.1 until you're comfortable with it because it's alot faster using the default valu than it used to be.

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OK, for all those that think autodocking sucks, let me give you a little run down on how to get the best results. First, use your preferred method to get the active vessel close to the target, whether that be rendezvous autopilot or manual, now:

For these instructions, the active vessel is "A" and the destination vessel is "B".

1. switch to the B, select "control from here" on the desired docking port.

2. target the desired docking port on A that will be docking. set smart ASS to tgt+

3. switch back to A

4. select the desired docking port on this vessel and "control from here".

5. target the same port on B from step 1. set smart ASS on A to tgt+

6. both ships should now be pointing the desired docking ports straight at each other. turn on autodocking.

7. sit back and be amazed by how very little monoprop is used.

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Wow, docking is massively different. Very little RCS usage that I see, but boy does it push that speed limit. I like it.

One problem I've found (but haven't narrowed down) is that if you're negative position relative to the docking vector (vector pointing outward from the target dock - toward where the active docking vessel will be) then the docking vessel appears to orient the right way, but thrust the wrong way - so it flies away from the target. If you get positive position relative, it works fine. I'm not sure precisely what the condition is that causes the problem, but it did it it twice to me and that appears to be when it happens. Essentially, I'm rotating my orbital boost stage 90 degrees and re-docking to the same craft.

Confirming this bug, I also had one of my ships fly away from the station when I came in on the wrong side and asked MJ to auto-dock to a port on the far side of the station from where I was.

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An other version (2.0.13243.1312)

- Ship flying away when docking from opposite side of the station

- Better RCS usage, I hope

- Speed Limit can't be negative

- Default docking speed is set to 0.5m/s now. Check yours and don't let it at 0 ( unlimited speed ).

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@triffid_hunter

I agree that right now it's not from perfect but it does the job in my last version.

I implemented your suggestion a few min ago in an newer version ( 2.0.13243.1409 )

Rendezvous autopilot will have to wait for now.

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I like how the rendezvous autopilot currently works, it prioritizes less time spent flying rather than saving fuel by insisting heavily on using phasing orbits. A rendezvous without the phasing orbit is already possible through the manuever planner (inclination match -> hohmann transfer -> match velocity at closest approach).

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sarbian, you're a machine. :) Haven't tested the new docking yet but people seem excited about it, just wanted to thank you for picking up the torch on this mod that many of us deem essential.

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