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[1.12.x] Anatid Robotics / MuMech - MechJeb - Autopilot - [2.14.3] [4th March 2023]


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On 1/6/2020 at 11:17 PM, ChrisF0001 said:

Might I ask if there's been a change to how Rover Stability Control works in the last few versions?  While driving forward it seems okay, if a little weak, but if a rover is stopped with Stability Control on it seems to dramatically flip out (for lack of a better description).  I suspect that if the velocity is 'backwards' for any reason (reversing, rolling backwards down a slope, rounding error...) it's trying to pull the nose around to comply with the velocity vector by hook or by crook, even if this involves grinding the nose into the ground or scraping off all the solar panels.

It seems much more pronounced on the Mun rather than just outside KSC...

I'm having this same issue. It's making AFK rover voyages impossible. I'd like to be able to stop at every waypoint and quicksave, but as soon as i pass below 3m/s, the rover starts spazzing out. The stability assist should reduce to 0 below a configurable speed.

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Regarding the rover issue, here is what Jim DiGriz said the other day when I asked him about this:

 

On 2/27/2020 at 3:07 AM, Jim DiGriz said:

And the problem is that I've never used rovers, and don't think I've ever touched the rover autopilot once.  MJ is way too sprawlingly vast.  Similarly I haven't had any time to play with any of the new features.  And there's hundreds of hours of work that I'd like to get done ahead of that just to make rockets work better.  I've got some code right now which implements a quaternion-based PID controller which might be a quantum jump up in PID control and fix a lot of the issues people have with controls which cuts across the board.

Before I touched rovers/BG I'd probably look at fixing the rendezvous autopilot since there HAS to be a way to make that better and easier to use without wasting so much RCS.

In the RSS/RO world people have been bugging me a lot about mid-course corrections since often plane changes in low orbit are very suboptimal.  Could also do bi-elliptic transfers now that the maneuver planner supports multi-node planning (which is like a 4 year old user request).

 

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Can anybody explain to me why my satellite is stuck rolling? take a look at the indicator, this is without any input.
This issue occurs after a maneuver made with Mechjeb's Manuever Planner is finished/cancelled
Usually (not 100%) it goes away when I save and load until the next manuever.


qd8BIu7.jpg

 

The only part that has mechjeb enabled is a drone core in the back part of the satellite you see, but even when mechjeb is disabled on every part it keeps rolling, so I'm not sure what is happening

 2KntXCO.png

 

Here is a picture of my mod list in case it's another mod, doubt it though

https://i.imgur.com/XGUhOvd.png

Edited by Rodonies
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I guess this has been explained somehwere, but I can't find it, so I'm going to trust some of you has it "fresh" to link it to me (thanks in advance).

My ships are unable to land on target if there is an atmosphere (Kerbin mainly). Everything goes "well" until they touch the atmosphere, apparently the ship aerobrake much more than needed and making mechjen undershoot the target. Literally something like "Required braking vel: 1800 - Surface vel: 1750". I don't know what else to try, it always fails for between 14-70km (depending on the ship). What I'm doing wrong? 

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17 hours ago, Rodonies said:

Can anybody explain to me why my satellite is stuck rolling? take a look at the indicator, this is without any input.
This issue occurs after a maneuver made with Mechjeb's Manuever Planner is finished/cancelled
Usually (not 100%) it goes away when I save and load until the next manuever.

[snip]

The only part that has mechjeb enabled is a drone core in the back part of the satellite you see, but even when mechjeb is disabled on every part it keeps rolling, so I'm not sure what is happening

[snip]

Here is a picture of my mod list in case it's another mod, doubt it though

https://i.imgur.com/XGUhOvd.png

Your pictures don't tell us what operational mode you have MechJeb set to. Just having the MechJeb installed and enabled is like a cruise control in a car you have turned on, but you haven't a speed to hold yet.  As a minimum you need to activate Smart A.S.S and tell it to kill kill rotation.  When you give it a maneuver to execute MechJeb is taking control to execute the maneuver, but then goes back into standby waiting for you to tell it what to do.

4 hours ago, Treikan said:

I guess this has been explained somehwere, but I can't find it, so I'm going to trust some of you has it "fresh" to link it to me (thanks in advance).

My ships are unable to land on target if there is an atmosphere (Kerbin mainly). Everything goes "well" until they touch the atmosphere, apparently the ship aerobrake much more than needed and making mechjen undershoot the target. Literally something like "Required braking vel: 1800 - Surface vel: 1750". I don't know what else to try, it always fails for between 14-70km (depending on the ship). What I'm doing wrong? 

Just search this thread for "atmosphere" and you find lots of people with the same complaint.  MechJeb is only accurate in vacuum.  MechJeb will get you safely down in atmosphere, but it isn't capable of precision as it doesn't accurately account for the aerodynamics.  

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Well, at least is not my rockets fault. Thanks Tonka, I hope it can be fixed, it doesn't really sounds very difficult to workaround (if breaking vel is higher than real vel... just use thrusters). It will waste a lot of fuel, but it will be more accurate until there is someway to accurately account the aerodynamics.

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On 3/1/2020 at 11:34 PM, Tonka Crash said:

Your pictures don't tell us what operational mode you have MechJeb set to. Just having the MechJeb installed and enabled is like a cruise control in a car you have turned on, but you haven't a speed to hold yet.  As a minimum you need to activate Smart A.S.S and tell it to kill kill rotation.  When you give it a maneuver to execute MechJeb is taking control to execute the maneuver, but then goes back into standby waiting for you to tell it what to do.

Just search this thread for "atmosphere" and you find lots of people with the same complaint.  MechJeb is only accurate in vacuum.  MechJeb will get you safely down in atmosphere, but it isn't capable of precision as it doesn't accurately account for the aerodynamics.  

after doing a manuever:

https://www.youtube.com/watch?v=t6sstj4mXoE

 

after quitting game or going to main menu and then loading the game and flying the satellite:

https://www.youtube.com/watch?v=IavuoGQwu1o

 

Why is it doing this, and how can I prevent it from happening?

Edited by Rodonies
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Ah, now I understand :) 

As per my experience (and the MJ developers are aware of this, just scroll back a few pages. Quoting Jim DiGriz "Yeah MJ really needs a proper finite burn executor"), during the finishing moments of a burn, the maneuver indicator naturally becomes unstable (to be expected), and MJ tries to follow it, hence the odd movements of your craft. It seems, the way you built your vessels made it very susceptible of this issue.

Your craft though should stay stable though after engaging SAS/Kill Rot for a few moments, yes? I.e., it doesn't start spinning after that?

Edited by VoidSquid
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1 minute ago, VoidSquid said:

Ah, now I understand :) 

As per my experience (and the MJ developers are aware of this, just scroll back a few pages. Quoting Jim DiGriz "Yeah MJ really needs a proper finite burn executor"), during the finishing moments of a burn, the maneuver indicator naturally becomes unstable (to be expected), and MJ tries to follow it, hence the odd movements of your craft. It seems, the way you built your vessels made it very susceptible of this issue.

Your craft though should stay stable after engaging SAS/Kill Rot for a few moments, yes? I.e., it doesn't start spinning after that?

Yes, it is stable during SAS/Kill Rot, but then it starts rolling again once it's turned off
you can see the roll indicator at the bottom left, it has a 1 bar offset, even if I manually try to roll the opposite way I can't reach the outer end of the indicator, it's like there is a thing permanently trying to roll.

Edited by Rodonies
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For what I can see in your video... did you forget the wires? When it load, it just stat to spin due to the game physics, or that is what I think. It is like when you load a rover, and it "jumps" on the surface of minmus/muna

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Sadly version 1.9.1 throws a fit and says it is incompatable, no mech jeb for me, or has anyone got it to work with the latest update, am i missing something
Basic KSP no expansions (no addons)

Edited by irondarren
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I'm using MechJeb2 v2.9.1.0 with KSP v1.9.1.2788 (x64) and all seems to work fine.

seems that there is no longer a *.version file in MechJeb2

- there are posts to mod the *.version file to get rid of the initial "not compatible"  warning pop-up.

 

 

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7 hours ago, irondarren said:

Sadly version 1.9.1 throws a fit and says it is incompatable

You could use a MJ dev version, the latest ones are marked as compatible up to KSP 1.9.99, just add "MechJeb2-dev | https://ksp.sarbian.com/ckan/MechJeb2-ci.tar.gz" to the CKAN repository list.

Be aware though that MJ #948 still has some issues with Porkchop Transfers, Jim DiGriz is working on this.

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On 3/7/2020 at 4:53 AM, Rodonies said:

after quitting game or going to main menu and then loading the game and flying the satellite:

As per the second video, I can't see MJ being involved here at all, might be an issue with your craft, your save game, or KSP itself. What KSP version are you using, what part mods? maybe you can share the .craft file?

 

Edited by VoidSquid
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I cant get it to work on the latest 1.9.x verison either, i literally copy the latest 2.9.2 mech jeb version into game data, but nothing loads in game. No error message either. This is with a fresh install ( no mods or addons ) of the latest KSP.

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