linuxgurugamer

[1.8.x] CorrectCoL - Stock Aerodynamics Design Aid Continued

Recommended Posts

@Boris-Barboris didn't have time anymore for this, so I've adopted it.  Original thread here:  http://forum.kerbalspaceprogram.com/index.php?/topic/130783-12-

Important - New Dependencies

Support has been added for the ToolbarController and the ClickThroughBlocker.  These two mods are now required for this to run.  

Links:

yLSfmvk.png

Download and source (MIT license):

Source code:  https://github.com/linuxgurugamer/CorrectCoL

Download:  https://spacedock.info/mod/789/CorrectCoL

License:  MIT

Stockalike CoL indicator for stock Aerodynamics, accounts not only for ILiftProviders. Please, don't try it with FAR (mod disables itself if FAR is found).

Simple static stability analysis:

oYei22M.png

Most graphs are torque-AoA relations:

green graph - current fuel levels.
yellow graph - emptyed fuel tanks.

Exceptions:
blue graph - pitch L/D ratio (wet).
blue vertical line - level flight AoA (wet).

 

aoa range - AoA and sideslip range to plot, degrees.
aoa marks - horizontal axis marks step, degrees.
aoa compress -  zero for 1:1 AoA axis, positive for quadratic compression. Helps to focus on important stuff near zero AoA while not loosing large-AoA behaviour.
speed - speed towards root part nose direction, m/s. Enter negative values to analyze retrograde stability.
altitude - meters above sea level.

Four simplistic and quite stupid trait labels, may sometimes fool you.

New features

  • AutoUpdate toggle, click this to have the graph update automatically anytime a change is made
  • Tooltips - Hover over the labels to get a tooltip
  • Selectable planets - Click this button to select a planet

Be careful with launch clamps, they are accounted for too. Also, move your craft by the root part a little after loading to ensure correct results for graph (strange API stuff).

 

I'm adding a settings page which will define the default behaviour of AutoUpdate and ToolTips

Selectable planets, would you like to remember the setting between sessions?

Edited by linuxgurugamer

Share this post


Link to post
Share on other sites

New release, 1.5.1:

  • Added Settings page
  • Added option to make tooltips optional
  • Added option to make the autoupdate default to on
  • Added option to specify using last selected planet 
  • Fixed bug when closing planet selection window

Share this post


Link to post
Share on other sites

great update, thank you! :)

i answers from the original thread:

Quote

I'm not sure what you are asking about in #5, the whole idea behind the AoA range is to show how it is at different AoAs.   In terms of the COL marker, this mod isn't touching that.

I think this mod is touching the COL marker ( the blue ball), for example it takes care of the structural pannel as shown in the 1st post but it changes also the alpha-zero from the stock 1° to 3° in the SPH, doesnt changez in the VAB (vertical down),
also with the graph we can see the amount of torque for a given AoA, but not where the COL is, it can move backward or up or both etc... but we only the graph we can't know easily (or we have to rotate the whole craft that will mess the part placement after this)

See this post:  http://forum.kerbalspaceprogram.com/index.php?/topic/130783-12-correctcol-v144-stock-aerodynamics-design-aid/&do=findComment&comment=2381097

why this suggest? because i try to give angle to my wings instead of flying with a pitch angle (for a level flight), so my plane is horizontal and my wing a bit tilted instead of tilting the whole craft (more drag):

not really level here, but you can see the idea.

so my suggest are:
-be able to change this alpha-zero ( at least in a .cfg file)

- display the red arrow show in my picture in the hangars to visualize it easily.

thank you for having read this. :wink:

 

 

Edited by Skalou

Share this post


Link to post
Share on other sites

FINALLY I understand what the graphs mean.  Never could decipher the descriptions before.

Share this post


Link to post
Share on other sites
8 minutes ago, Skalou said:

also with the graph we can see the amount of torque for a given AoA, but not where the COL is,

1). it is changed to 3 degrees in VAB.

2). there's no difference four your positively inclined wings. You'll move the slider to try to learn something graph already shows to you.

 

In terms of suggestions:

graphs are always normalized, so it's currently not possible to see how overdamped the craft is by the graph, you need both the graph and CoL. You could solve it by calculating short-period frequency of each axis:  sqrt(k / MOI) / (2 * pi),   k - linear slope of the graph ... and present it near the graph.

Share this post


Link to post
Share on other sites
1 hour ago, Boris-Barboris said:

1). it is changed to 3 degrees in VAB.

2). there's no difference four your positively inclined wings. You'll move the slider to try to learn something graph already shows to you.

 

In terms of suggestions:

graphs are always normalized, so it's currently not possible to see how overdamped the craft is by the graph, you need both the graph and CoL. You could solve it by calculating short-period frequency of each axis:  sqrt(k / MOI) / (2 * pi),   k - linear slope of the graph ... and present it near the graph.

1)VAB too? not only SPH? didn't noticed it, thank's.

2) the graph don't show me WHERE is the COL (blue marker), for the same torque the COL can be more down, or more backward, etc...depending of the position of the different parts, and it doesn't have the same effect on a craft. It can be easier to design plane (keep the craft horizontal in the SPH but move the numbers), maybe it is possible to deduce it by reading accurately the graph but i think it's harder.

Edited by Skalou

Share this post


Link to post
Share on other sites

To aid switching between building aircraft (which this helps) and rockets (for which this only seems to be confusing), could a switch be added to the in-game configuration to disable this mod?  (Added as a feature request issue on GitHub.)

Share this post


Link to post
Share on other sites
On 8/30/2017 at 1:32 PM, Jacke said:

To aid switching between building aircraft (which this helps) and rockets (for which this only seems to be confusing), could a switch be added to the in-game configuration to disable this mod?  (Added as a feature request issue on GitHub.)

Can you define "disable"?  Do you want the CoL indicator which this provides (which is more correct than stock) to be disabled?

It already has a button to display/hide the analysis window.  Who is this confusing?

Share this post


Link to post
Share on other sites
4 hours ago, linuxgurugamer said:

Can you define "disable"?  Do you want the CoL indicator which this provides (which is more correct than stock) to be disabled?

It already has a button to display/hide the analysis window.  Who is this confusing?

That's a very good question.  I've not used the analysis window yet, but I will be soon.  This is about using simple CoM wet/dry versus CoP analysis on rocket.

Stock and CorrectCoL indicators respectively (with CoM wet and dry courtesy of RCS Build Aid) on a rocket in the VAB.

Spoiler


screenshot_2017-08-31--17-50-48a.png

 

screenshot_2017-08-31--20-45-50a.png

 

For this application, the stock CoL as a CoP is a bit easier to use, as well as to see that there's no asymmetry that slipped into the design.

The CorrectCoL marker has shifted a bit ventral and forward, likely due to assuming a bit of pitchup as if the rocket is an aircraft.  For a simple CoM vs CoP analysis, it's a bit confusing.

This is a sounding rocket with no control and just Basic Fins for guidance.  Even for more advanced rockets like launch vehicles, they only pull a bit of pitch to start their turn off vertical to start the gravity turn for ascent to orbit.  Body lift can be important to check there for larger rockets and in fact using both and the analysis window would be helpful.

So, to be exacting, what I'm asking for is a switch to turn the marker from that of CorrectCoL as it is now to look more like stock.  This is for rocket design analysis where seeing the relative positions of CoM wet/dry versus CoP is what's desired.

Share this post


Link to post
Share on other sites
9 hours ago, Jacke said:

So, to be exacting, what I'm asking for is a switch to turn the marker from that of CorrectCoL as it is now to look more like stock.  This is for rocket design analysis where seeing the relative positions of CoM wet/dry versus CoP is what's desired

To "look" like stock and still behave the same, or to be able to disable it and let the stock col be visible?

Share this post


Link to post
Share on other sites
5 minutes ago, Rocket In My Pocket said:

Someday in the far flung future literally every single KSP mod will be adopted by @linuxgurugamer

I for one welcome our new modding overlord.

(Seriously dude, you are the man. Thanks for updating this and many other mods that I use.)

You're welcome.

Just an FYI, I do have a Patreon page

Share this post


Link to post
Share on other sites
2 hours ago, linuxgurugamer said:

To "look" like stock and still behave the same, or to be able to disable it and let the stock col be visible?

I think he wants the stock col to be visible

Share this post


Link to post
Share on other sites
1 minute ago, TheRagingIrishman said:

I think he wants the stock col to be visible

I think so, they actually do display slightly different angles.  I'm working on it

Share this post


Link to post
Share on other sites

New release, 1.6.1:

  • Added option in Settings to disable/enable in both VAB and SPH
  • Added option in settings as to whether it's active at all in the game 
  • Added toggle on analysis window to toggle between the stock CoL and this mod's CoL

Share this post


Link to post
Share on other sites
1 hour ago, linuxgurugamer said:

New release, 1.6.1:

  • Added option in Settings to disable/enable in both VAB and SPH
  • Added option in settings as to whether it's active at all in the game 
  • Added toggle on analysis window to toggle between the stock CoL and this mod's CoL

Just checking it out.  That's exactly what I wanted.  Thanks, @linuxgurugamer ! :)

Share this post


Link to post
Share on other sites

New release, 1.6.2.1:

  • Really Fixed exception on exiting editor this time.  Was actually a problem in the VAB
  • Fixed build to release a build compile rather than a debug compile

Share this post


Link to post
Share on other sites
4 hours ago, shdwlrd said:

Would it be possible to show the center of pressure?

It is not easy to calculate one, and sometimes it does not exist.

Share this post


Link to post
Share on other sites
11 hours ago, Boris-Barboris said:

It is not easy to calculate one, and sometimes it does not exist.

Ok, Thanks for the reply.

Share this post


Link to post
Share on other sites

Thank you very much for this mod. It saves so much head-ache when designing almost anything.

It would be even better if the graph had vertical axis labeled or the scale were displayed somewhere.

I found that it is possible to make a barely stable airplane but the pitching moment would look perfectly (flat decreasing line). I think what happens is that the pitching moment is very low across all AoA, but the scaling of graph made it look like it was OK.

Share this post


Link to post
Share on other sites
18 hours ago, prykpryk said:

Thank you very much for this mod. It saves so much head-ache when designing almost anything.

It would be even better if the graph had vertical axis labeled or the scale were displayed somewhere.

I found that it is possible to make a barely stable airplane but the pitching moment would look perfectly (flat decreasing line). I think what happens is that the pitching moment is very low across all AoA, but the scaling of graph made it look like it was OK.

The graph is relative, there are no units or scales to display

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.