sarbian

[1.8.x] Anatid Robotics / MuMech - MechJeb - Autopilot - [2.9.1] [15 November 2019]

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23 hours ago, sumghai said:

https://github.com/sumghai/SDHI_ServiceModuleSystem/archive/7c3064ad99eac2c1a873e86585f36bccbd6214fc.zip

The part in question is GameData/SDHI/Service Module System/Parts/SDHI_Service_Module/SDHI_Service_Module.cfg.

Ok, I found 2 problems that I fixed and it displays the dv properly but shows only one stage. I need to fix that so it shows 2 stages but I'll finish that when I am more awake :)

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4 hours ago, Jacke said:

Here's the Module Manager script I use to add MechJeb to all Command pods and the External Command Seat as well as unlock all functions at Career start.

Yeah that works, thanks

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I really want to see an overhaul of the landing guidance, the one thing I see needs a bit of work. When I get Mechjeb to land on something (like a barge), it seems to just land wherever its horizontal speed reaches zero. I want a mode where MJ will not pass a certain threshold (How far I'll let it land away from the target) and if it does, it either does a hop or drifts towards the target and then lands. Also, instead of locking to retrograde, when it gets slow, don't make it follow retrograde leading to growing (and often deadly) oscillations, make it stay vertical to an extent.

Also, none of the links at the bottom of your post work and the manual tried getting me to install what I can only assume to be a virus or bitcoin miner. I may also post this on GitHub in the case you don't take suggestions from the forum.

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I am eagerly waiting for your code submission. You'll either see that it is harder to code than to explain or you'll submit better code.

The ingame manual link was fixed last Sunday. (and I just fixed the one in the post now, thx for the reminder).

 

Edited by sarbian

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Just now, sarbian said:

I am eagerly waiting for your code submission.

The ingame manual link was fixed last sunday.

 

I don't know coding, only a few lines which I can't remember. I just tried the manual after the other links wanting to see the other mechjeb model, and I can confirm it tried making me install a sketchy chrome extension. You probably think I'm talking about the in-game manual link which I never tested. I know what it's like when you're tired and can't think straight (Me on a school morning every day). Speaking of the landing, I want MJ to do something like https://youtu.be/Xoe6siQL7BA?t=5m58s and https://youtu.be/Xoe6siQL7BA?t=8m15s where it can do mid-landing burns to get closer to the target. I know the landing guidance was just probably made to land in the general vicinity of a landing spot but I'd love to see an improvement of the landing algorithms to do cool stuff like that.

 

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@Bej Kerman In the latest few releases I've been able to use RCS and I think even pitch and yaw control works to move the touchdown point around during final descent, but I had a couple landings where RCS control seemed locked out. 

I used to have to come up with a unique lat/long target for each unique design if I wanted a hit the same coordinates on the ground. It only mattered trying to land near bases. In the most recent updates it's gotten a lot tighter. Last night I had a lander touchdown within 10m of the target where I was used to 200m errors and doing a hover taxi with the translatron to bring them in closer after touchdown.

I have my Mun & Minmus base's landing zones in the Landing Sites.cfg. I've gone back to letting landers use the same landing zone coordinate for all designs and most seem to be hitting it better, but I've also started using RCS to jog the landing spot to precisely where I want it.

Edited by Tonka Crash

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1 minute ago, Tonka Crash said:

@Bej Kerman In the latest few releases I've been able to use RCS and I think even pitch and yaw control works to move the touchdown point around during final descent, but I had a couple landings where RCS control seemed locked out. 

I used to have to come up with a unique lat/long target for each unique design if I wanted a hit the same coordinates on the ground. It only mattered trying to land near bases. In the most recent updates it's gotten a lot tighter. Last night I had a lander touchdown within 10m of the target where I was used to 200m errors and doing a hover taxi with the translatron to bring them in closer after touchdown.

I have my Mun & Minmus base's landing zones in the Landing Sites.cfg. I've gone back to letting landers use the same landing zone coordinate for all designs and most seem to be hitting it better, but I've also started using RCS to jog the landing spot to precisely where I want it.

Maybe it's just me and my odd obsesion with trying to reuse boosters on planets that have atmospheres (Kerbin, I'm not falcon heavy to Duna and back level).

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@Bej Kerman I'm not sure about Mechjeb's landing guidance in atmosphere my experience is mostly moon landings. Most of my reentries have been moon returns where I don't have a whole lot of dV available to choose my reentry target, so I just let them land where they can. I did do a Mechjeb guided landing from a station in Kerbin orbit recently (don't remember which Mechjeb release) and it at least hit the right continent :) I could see KSC on the coastline as I drifted down under the parachutes. I use Stage Recovery and avoid actually trying to flying in atmosphere as much as I can.

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12 minutes ago, Tonka Crash said:

@Bej Kerman I'm not sure about Mechjeb's landing guidance in atmosphere my experience is mostly moon landings. Most of my reentries have been moon returns where I don't have a whole lot of dV available to choose my reentry target, so I just let them land where they can. I did do a Mechjeb guided landing from a station in Kerbin orbit recently (don't remember which Mechjeb release) and it at least hit the right continent :) I could see KSC on the coastline as I drifted down under the parachutes. I use Stage Recovery and avoid actually trying to flying in atmosphere as much as I can.

 

Today I was experimenting, seeing if MJ could land on a barge (being slightly less than twice as far as the abandoned airstrip, on the equator). It landed about 1km away most of the time but if I was careful I could guide MJ closer to the barge. Hope to see the landing guidance become more useful for things like this.

https://imgur.com/a/RPUOhfE

^Ship I used intended as something to practise using FMRS^

Edited by Bej Kerman

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5 hours ago, Bej Kerman said:

[snip] I just tried the manual after the other links wanting to see the other mechjeb model, and I can confirm it tried making me install a sketchy chrome extension. You probably think I'm talking about the in-game manual link which I never tested. [snip]

what .. exact link are you talking about? i just tried each and every one of sarbian's footer links, and none acted in the way you refer to.

 

 

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It's difficult to contact lamont-granquist so I just type it here:

Could it be that https://github.com/lamont-granquist/MechJeb2/releases/tag/mchenry17-145 works well with PEG but does not work with "Classic Ascent Profile" at all?

Like "normal" MechJeb behaves the other way around?

Edit:
Scrap that, it's some unknown bug (no exceptions in the log for 15 minutes now):
After reverting to launch pad I cannot launch at all - the 1st stage engines are not activated.

It doesn't matter which ascent guidance method I choose.

Edited by Gordon Dry

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3 minutes ago, Cheesecake said:

Your links to Imgur don`t work.

Can't get them to work.

EDIT: Fixed it

Edited by Bej Kerman

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5 minutes ago, Bej Kerman said:

Can't get them to work.

You must use the BBCode Sharelink in imgur.

Mouseover your Pic. At the right is a simple arrow --> Get share link --> Copy BBCode --> insert the link in your post.

For Albums you can use the Embed Post Code on the right when you opened your album in imgur..

Edited by Cheesecake

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1 minute ago, Cheesecake said:

You must use the BBCode Sharelink in imgur.

Mouseover your Pic or Album. At the right is a simple arrow --> Get share link --> Copy BBCode --> insert the link in your post.

This is going off topic... Plus I don't get an arrow.

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This is also offtopic then, but ...

Spoiler

I always copy the direct link from imgur and paste that here ... this way I make sure the pictures are loaded and shown.

And I use spoilers when there are too many pictures to show.

Edited by Gordon Dry

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Also offtopic about imgur.com

Spoiler

I've recently had serious issues with the images from imgur.com not loading here when shared in forum posts, just leaving the alternate text "<random string>.<picture format tag>".  I'm always having to go back to a tab on imgur.com and clear its cache and cookies then opening the posts in a new tab to actually get the pictures to load.

Also use spoilers to compact away pictures.

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A question for the MJ community, of the how would you use Mechjeb to do this variety.

So I'm playing in Career Mode, and it's early days, Year 1, Day 9. I've placed an unmanned probe in Mun Orbit, and that's my best achievement so far. Now there's a mission-

	Position satellite in polar orbit of Kerbin
	AP: 8,403,702
	PE: 7,817,928
	Inclination: 90 degrees
	Longitude of Ascending Node: 359.7 degrees
	

OK, the first three parameters, no problem. Used KSP and MJ enough to do it in my sleep. But that Longitude of Ascending Node business, what exactly is that, and how would you use Mechjeb to achieve it?

 

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1 hour ago, El Sancho said:

A question for the MJ community, of the how would you use Mechjeb to do this variety.

So I'm playing in Career Mode, and it's early days, Year 1, Day 9. I've placed an unmanned probe in Mun Orbit, and that's my best achievement so far. Now there's a mission-

 


	Position satellite in polar orbit of Kerbin
	AP: 8,403,702
	PE: 7,817,928
	Inclination: 90 degrees
	Longitude of Ascending Node: 359.7 degrees
	

 

OK, the first three parameters, no problem. Used KSP and MJ enough to do it in my sleep. But that Longitude of Ascending Node business, what exactly is that, and how would you use Mechjeb to achieve it?

I wouldn't.  I just line up the launch site with the contracted orbit line in map view by waiting until Kerbin rotates to put the contract line almost over the launch site (or the launch site under the requested orbit, if you prefer), accounting for the time spent in the ascent.  If necessary, I adjust the final orbit to match the contracted orbit, or at least get it close enough to meet it.  Be careful to launch in the correct direction, i.e. North or South.

Edited by Brigadier
Spelling error

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@El Sancho Mechjeb does have a Maneuver Planner mode to change Longitude of Ascending Node. (the point where your orbit crosses the equator). It may not be unlocked yet for you in career. It can take a lot of fuel to do large changes of this once you are already in orbit. As Brigadier said it's simpler to wait for the ascending node to be overhead. Make sure you launch north on the ascending node, if you launch on the descending node you need to launch south or you'll be going the wrong direction. I use Woomerang for these kinds of polar orbits just to add some variety.

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18 hours ago, Tonka Crash said:

@El Sancho Mechjeb does have a Maneuver Planner mode to change Longitude of Ascending Node. (the point where your orbit crosses the equator). It may not be unlocked yet for you in career. It can take a lot of fuel to do large changes of this once you are already in orbit. As Brigadier said it's simpler to wait for the ascending node to be overhead. Make sure you launch north on the ascending node, if you launch on the descending node you need to launch south or you'll be going the wrong direction. I use Woomerang for these kinds of polar orbits just to add some variety.

@Tonka Crash  Successfully completed, thanks very much! With 1800 Dv to spare, even.

You're right about the Dv costs of changing the Longitude of Ascending Node, they are  significant, but the higher your orbit, the less it costs. This I discovered by simple  trial and error.

What I did was note the direction of the glow chasing itself around the circle, and found I needed to launch South. That got me close. Then I boosted orbit to around 3000km, corrected alignment, corrected Longitude of Ascending Node, then did a final correction to Alignment. This got me in the right plane. Then I used Planner to setup a standard increase to the desired Ap of 8000 or so, but it was way in the wrong place, so I clicked on the maneuver node in map view, and just dragged it around until my planned Ap lined up with the desired Ap , jiggered the duration of thrust a bit, and had my Ap just right. From there getting the Pe right was just a simple burn, and I got that happy green color. Ten seconds later, mission was complete.

This highlights one of the things I have said before about  Mechjeb; there are many features I have yet to explore.

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5 hours ago, El Sancho said:

You're right about the Dv costs of changing the Longitude of Ascending Node, they are  significant, but the higher your orbit, the less it costs. This I discovered by simple  trial and error.

Changing the LAN will change the orbital inclination, AKA plane change, not in size but in direction, so it's a special case of that.  And because it's an orbital velocity vector change, it takes less dV if the orbital velocity is smaller, as it usually is for higher orbits.  Most astronautics texts have a section where a rough calculation is done to determine the minimum dV for a plane change by adding in 2 other maneuvers, one to raise the Ap to a higher altitude, where the actualy plane change maneuver occurs, then a third to lower the Ap back down.

 

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On 9/24/2018 at 2:31 PM, sarbian said:

It's not a problem I have and no one else complained about it. So I would rather have a vessel file so I can see what is going on. 

 

I did further testing. It has nothing to do with the vessel or other mods. It`s MJ itself. I installed an older MJ-version for 1.3.1 in KSP 1.4.1.That did it. Now it works like always.

So, I think a change in MJ cause this issue.

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Hi Everyone!

I am having a rather strange problem with the Powered Explicit Guidance in Mechjeb ascent autopilot.

Sometimes, seemingly randomly, the stage analysis window throws NaN, instead of some of the numbers for the stages. When that happens, A, B and pitch become NaN. The time to go reading is sometimes an erratically changing negative number or just another NaN as well.

If I launch like this, the guidance mode will never engage, and the autopilot will just stick to prograde indefinitely, after the pitch program.

It, usually, tends to happen after reverting a flight, but sometimes, immediately after starting the game, or even creating a completely new save. It does not seem to depend on the vessel or whether it is physically capable of reaching orbit.

I should say that I am also running Real Solar System, and the basic mods from the Realism Overhaul pack, but everything seems to work, so not sure, if this could be contributing.

What could be causing this?

Thank you!

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