sarbian

[1.8.x] Anatid Robotics / MuMech - MechJeb - Autopilot - [2.9.0] [19 October 2019]

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16 hours ago, sarbian said:

It s at the bottom of the maneuver planner window

To do what ? Ascent works fine. Landing was added recently and seems to work too.

Landing Guidance in atmospheric planets needs work. It used to be ok, I used it back when Mr The Bull's PPTS was still up to date, and MJ could land it with near precision accuracy. Attempting to land recoverable stages (a la SpaceX) and capsules to the KSC pad is like rolling a pair of die, roll snake eyes or two 6s to land near your target. Once the Landing guidance didn't even bother with a boost back for the booster, just followed the current trajectory and made an almost constant deceleration burn. It had more than enough DV for boostback and landing

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On ‎2‎/‎18‎/‎2018 at 3:46 PM, Duke Leto said:

Understood.  I think in the meantime I need to work on some of the more fundamental issues I have with getting my ginormous SpaceY fuel freighters to dock successfully.

Hi,

I've been there...especially when building SpaceY fuel freighters. The heavy duty RCS modules are like 12 -15 times more powerful than stock and they consume 12 - 15 times the monoprop. I was faced with the choice of using those monster monoprop tanks or make smaller fuel transports. I settled on going back to a smaller vessel, using the regular 5 way RCS part and using verniers, since I have a lot of fuel onboard.

A workaround to the MJ issue (latest dev build) is that I use warp. I use MJ to get the ship moving to get it aligned to the starting point with a .4 speed limit, and hit a x5 warp. The ship drifts towards the target spot but uses no monoprop. Looking at the MJ docking screen, when the doc axis difference gets small, I stop warp. There's a burst of monoprop to stop lateral movement and pushes forward to dock. Hit warp again to get close and then stop. Another alignment burst at the end, and you're done. It can save a lot under the right circumstances.

It looks like the MJ team knows the issues, but I would like them to consider that, during the docking process, MJ never seems happy with the speed of the ship. It always feels the need to  correct something, especially the scenario when you are lined up and moving forward from about 30m. RCS will burn to accelerate to the speed limit, which stops at about 20m, then will actively burn to decelerate to close to 0. If the target is stable, there should be a coast window where no RCS is needed. The burn just before dock can also be very extreme. I've had vessels at .1m not dock because the RCS is burning in the opposite direction harder than the docking port pull force.

Hope this helps

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On 2/20/2018 at 9:10 AM, Gilph said:

Hi,

I've been there...especially when building SpaceY fuel freighters...

A much more basic practical design flaw was crushing me. 

Since I had constructed the stations that the SpaceY 10m freighters dock with using clamp-o-trons of a standard diameter attached to a hubmax, and wanted lots of distance between the docked freighters and good aerodynamic properties on liftoff, I gave the freighters noses of about the same length as the main SpaceY body holding the fuel, tapering from 10 m down to 1.25 with various sloping tanks and adapters, and some reaction wheels too... in a fit of poorly thought out insanity.

This meant that the docking nose had a habit of swaying back and forth, which made poor MechJeb's job even more difficult.  It tended to get close to the docking target but never able to finish because the docker was whipping from side to side in a 3-5m radius, (even with the reaction wheel turned off.)

A major redesign with some xtra-wide control systems on top of the freighter with a 10 m fairing underneath and a clapmp-o-tron Sr on top has shown a lot of promise, but it means deorbiting all the current freighters.  Oh well, at least the tourist missions are making it rain money.  :)

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On 2/16/2018 at 3:13 AM, MikeO89 said:

I'm going to probably asking a really stupid question about using mechjeb to launch to target. Using FASA Apollo mod going to the mun and back using my buddy Mechjeb all the way. Have Apollo  CSM orbiting the mun. Land LEM on Mun. Here's where my issues begin. I use Ascent Guidance and set it to target (after setting CSM as target.)   This is where it gets weird. It's a hit or miss thing on this.   About 2 out of every 3 times I try this the LEm blasts off in the opposite direction of orbit of the CSM.   So to try to  get on matching  a  plane   to one thats  going the opposite direction in orbit,  that's going take a lot work and fuel. So my stupid question is how do i know which direction the rocket is supposed to be going when I launch it to be able to rendevious with it? And why is Mechject when choosing to launch to Rendevious, sending the ship in the wrong direction?

I have a theory about this which is that your CSM is orbiting the moon retrograde. If, in map view, you zoom out such that Kerbin is behind the moon, you want your insertion into Munar SOI to come from the left. This will make sure your orbit is rotating in the same direction as Mun's rotation, because that's the direction that Mechjeb will launch with ascent guidance. 

I have recently used ascent guidance from the Mun and Minmus for a landing in every individual biome, with a launch to rendezvous, so that's over 20 launches, and Mechjeb never launched retrograde. My guess is that your CSM is orbiting in the wrong direction.

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2 hours ago, drhay53 said:

I have a theory about this which is that your CSM is orbiting the moon retrograde. If, in map view, you zoom out such that Kerbin is behind the moon, you want your insertion into Munar SOI to come from the left. This will make sure your orbit is rotating in the same direction as Mun's rotation, because that's the direction that Mechjeb will launch with ascent guidance. 

I have recently used ascent guidance from the Mun and Minmus for a landing in every individual biome, with a launch to rendezvous, so that's over 20 launches, and Mechjeb never launched retrograde. My guess is that your CSM is orbiting in the wrong direction.

Should be easy to check, go to the orbiting craft and look at the inclination, its is around 0 then its going the right direction, if its around 180 then thats the problem.  And I agree, I recently did a number of launches from the mun with a reusable lander using ascent guidance and it worked great. 

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That's got to be it, thanks guys. When I warped past POI to see me facing the mun, I would select change periapsis in mechjeb  to 30km and sometimes it would create the periapsis on the left of the mun and other times on the right side of the  mun. Whichever one  it was I just went with it and then circularized. Never paid much attention if it was a clockwise or counter-clockwise orbit as I didn't think it made much difference in the scheme of things. Guess it does to Mechjeb. If it was out of inclination with mun's orbit around kerbin, I would just correct it on the way back to kerbin. Lately with that issue I was having, I landed the LEM then switched back to the CSM, warped it around the mun to be close to the LEM, switched back to the LEM where I could see the CSM coming past and then launch to it's direction manually following the CSM into orbit. Was actually fun doing it that way. I'm a super rookie in this game and the pleasure I get out of doing a successful Apollo to the mun and back mission causes me much coolness. It's like stepping back in time every time I do it. Mechjeb and the FASA mod are my true buddies.  More than worth the price of the game for those two alone. My grandson will come into my room and say, "papa, you playing this mission again"?  I would say with an excrement eating grin on my face, "yup".

Edited by MikeO89

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7 minutes ago, MikeO89 said:

That's got to be it, thanks guys. When I warped past POI to see me facing the mun, I would select change periapsis in mechjeb  to 30km and sometimes it would create the periapsis on the left of the mun and other times on the right side of the  mun. Whichever one  it was I just went with it and then circularized. Never paid much attention which direction the orbit was I didn't think it made any difference in the scheme of things. Guess it does to Mechjeb.

One note, it does make a difference in a different way, in the sense that if you launch prograde (with the direction of the planet's rotation), it requires less delta-v to get to orbit, since you gain the benefit of the velocity at the surface of the rotating planet. Because with ascent guidance, you could launch retrograde (absolute value of inclination greater than 90). 

 

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23 hours ago, YaitsBilly said:

How do I keep windows in the same position after going from  hanger to launch and back an fourth?

Editor and flight position are saved separately. But the position in the editor should always be the same. Do they change for you ? Something may not save properly so I ll need a log (see first post first line) 

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On 2/22/2018 at 9:17 PM, MikeO89 said:

I would say with an excrement eating grin on my face, "yup".

:)

Still the ascent AP should not put you in the wrong orbit so something may be broken somewhere. I'll have a look when I feel less ill.

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While in orbit around minmus picking a landing target does not display coordinates and only focuses on minmus. As far as I can tell, minmus is the only planet/moon affected. Disabling OPM fixes this but its one of my favorite mods and I'd rather not play without it if possible. Below are two screenshots, one showing the mod working without OPM, the other showing that you cant see or select coordinates with OPM installed. https://nofile.io/f/MZAWEOxsSM1/output_log.txt
https://nofile.io/f/KDOQSucmm4E/KSP.log
36635807-8bb04fa6-1989-11e8-9239-d6160ff

36635852-3ceca49a-198a-11e8-82ab-afa90e3

Edited by GhastlyKerbal

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Hi sarbian,

I would like to inquire about the effect of MJ+RO on RT. With MJ+RT (exclude RO), I observe that on a vessel equipped with MJ part, RT is not able to enforce signal delay on its own commands (seem got bypassed by MJ). If a vessel is without MJ part, RT commands are correctly delayed. With RO+MJ+RT, every command part has MJ by default. As far as I can tell, signal delay is skipped on all commands issued by RT.

The comment for DeactivateControl flag in MechJebCore.cs says MJ can be instructed not to control the vessel (not ideal for RT players who want to utilise MJ's control functions). The current MJ behaviour does not have the concept of signal delay and I do not see a way to shield RT commands from MJ. Is it correct?

Thanks.

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7 minutes ago, TaxiService said:

The current MJ behaviour does not have the concept of signal delay and I do not see a way to shield RT commands from MJ. Is it correct?

It is. And it will not change until the whole MJ UI is redone with an event system (and modern Unity UI) and that will not be for a while.

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I am here to determine if an issue is on my end or if anyone else is having it, before I submit the bug. Does anyone else have the issue of not being able to pick target for auto land on map, and having the auto land window bug out whenever you tick landing predictions??? Ill be submitting logs when I get access to my PC.

Log

https://www.dropbox.com/s/dh5ix1xf1nq0ur0/output_log.txt?dl=0

Edited by Yuri kagarin56

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38 minutes ago, Yuri kagarin56 said:

I am here to determine if an issue is on my end or if anyone else is having it, before I submit the bug. Does anyone else have the issue of not being able to pick target for auto land on map, and having the auto land window bug out whenever you tick landing predictions??? Ill be submitting logs when I get access to my PC.

Log

https://www.dropbox.com/s/dh5ix1xf1nq0ur0/output_log.txt?dl=0

I can't read the log from work but I guess you have Kopernicus and a planet pack installed ? Kopernicus had a bug where it deleted the biome map of planets. MJ (the stock game code actually) has a bug when trying to display the biome of a planet with no biome map. I added a fix in MJ in the dev version but Kopernicus 1.3.1-7 fix the biome bug so you should update

Edited by sarbian

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39 minutes ago, sarbian said:

I can't read the log from work but I guess you have Kopernicus and a planet pack installed ? Kopernicus had a bug where it deleted the biome map of planets. MJ (the stock game code actually) has a bug when trying to display the biome of a planet with no biome map. I added a fix in MJ in the dev version but Kopernicus 1.3.1-7 fix the biome bug so you should update

Ill have to download the latest dev version then. I do have the latest kopernicks though. And is that what would be causing the entire landing guidence window to bug put when I hit landing prediction?

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6 minutes ago, Yuri kagarin56 said:

And is that what would be causing the entire landing guidence window to bug put when I hit landing prediction?

The window displays the biome of the predicted landing point. To do that MJ call a stock method that crashes and throw an exception if the planet has no biome map. Since MJ still uses the old UI the window is messed up because the code crashed while building the window. The old UI is... annoying to stay polite. I stared working seriously on the new UI yesterday but it will take time

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Im sure this is not mechjebs fault but my design. What causes jeb to keep searching for its target point on the nav ball? It just keeps fighting to line up, not all the time, just certain maneuvers. What causes it not to autostage, every other stage works except my first stage. It is my booster separation that it wont do. However it use to when i first built the rocket. All the other stages work.

Most of the rocket is KW Rocketry.

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5 hours ago, viperwolf said:

Im sure this is not mechjebs fault but my design. What causes jeb to keep searching for its target point on the nav ball? It just keeps fighting to line up, not all the time, just certain maneuvers. What causes it not to autostage, every other stage works except my first stage. It is my booster separation that it wont do. However it use to when i first built the rocket. All the other stages work.

Most of the rocket is KW Rocketry.

I've seen this behavior before with a long rocket and inadequate control authority.  It appears to be in the core game as it can be reproduced with a Kerbal on EVA with the jetpack throttled way down.

The problem appears to be waiting until too late to attempt to stop the rotation of the rocket, it overshoots the target and then has to go back looking for it--and overshoots again.  And again and again and again.

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14 hours ago, Loren Pechtel said:

I've seen this behavior before with a long rocket and inadequate control authority.  It appears to be in the core game as it can be reproduced with a Kerbal on EVA with the jetpack throttled way down.

The problem appears to be waiting until too late to attempt to stop the rotation of the rocket, it overshoots the target and then has to go back looking for it--and overshoots again.  And again and again and again.

Yeah that sounds right, I was wondering if i had to much control. I have RCS in the right positions according to what Ive read about it. I also have a reaction wheel on my "launcher" , plus the torque of the guidance or command pod Im using at the time.

 

Edit: Hmmm im not sure what Ive done, but even my proven and trusted builds are chasing the nodes now. No use in worrying to much about it, the update will hit March 13th and probably knock everything out of whack again :). ugh when i think about i have 12 Rovers and 19 Sats launched.

Edited by viperwolf

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Well 1.4 is out and it sneaked on me. I ll update later today but since I see no one complaining I guess it justwork™ ?

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