[1.2][beta] Boosteriferous - SRB Thrust Profiles

[soundnfury]

The Space Shuttle's SRBs were designed to have a burn rate that varied with time, decreasing the thrust while the vehicle was passing through Max Q. So why can't KSP solid rockets do the same?

Now they can! Boosteriferous allows you to set up a thrust profile in the VAB / SPH. Instead of that dowdy old 'Thrust Limiter' slider, you can now set up your solid rockets with a variety of configurable thrust profiles, some of which require technologies to unlock.  Higher-tech SRBs can be throttled down further, and the "Kickback" SRB even has Thrust Termination Ports to shut it down when you need to abort!

Source code: https://github.com/ec429/boosteriferous
License: GPLv2
Download: from GitHub or direct from my website.

Edited October 29, 2016 by soundnfury
Released 0.2.3 (for KSP 1.2)

[Nansuchao]

Wonderful idea. Will it works also for modded SRBs?

[soundnfury]

[quote name='Nansuchao']Wonderful idea. Will it works also for modded SRBs?[/QUOTE]

Not automatically; you'll need a ModuleManager config to add the partmodule and parameters. See the included 'Squad_Boosters.cfg' file for an example. The segOptions should be listed in descending order, and must all be in (0, 1].

[Bev7787]

Great mod, this idea has been circulating for a long time

[soundnfury]

[b]Boosteriferous 0.1.1 released[/b] - mainly a bugfix release.

[list]
[*]Feature: add Thrust Termination Ports to the "Kickback" SRB, in the "Abort" action group by default.
[*]Feature: add editor part info.
[*]Fix: Propagate thrust profile changes to symmetry counterparts.
[*]Fix:Trigger vessel cost recomputation when changing the number of segments.
[*]Interop: add a .version file for use if the user has AVC / MiniAVC installed.
[/list]

Updated download links in the OP.

[Gaarst]

I don't know much about modding, but can't you put a config file with:
[code]@PART
[*]:HAS[@RESOURCE[SolidFuel]]{
MODULE{
name = //whatever your module name is
}}[/code]
to target all parts using solid fuel ?

[jonrd463]

Hey, awesome! Anyone who watches EJ_SA's stream probably knows about this lacking feature in stock. He's got a shuttle that he uses as his LKO delivery workhorse and has set up liquid fuel boosters with multiple engines that he shuts down through the phases of launch to simulate this very feature. I do the same thing, but always thought that method was just a tad "hacky", since it involved clipping engines.

Does this work with all SRBs. including mods? I've already got a few in mind that I want to use this with.

[DECQ]

It's almost what I was looking for, there is only one question, it can only be applied to the solid booster?

[soundnfury]

[quote name='Gaarst']I don't know much about modding, but can't you put a config file with:
[code]@PART
[*]:HAS[@RESOURCE[SolidFuel]]{
MODULE{
name = //whatever your module name is
}}[/code]
to target all parts using solid fuel ?[/QUOTE]

In general yes; but Boosteriferous needs some parameters on the module (segOptions and maxSegments) which should be different for different boosters. (Higher-tech boosters have more options and more segments.)

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[quote name='jonrd463']Does this work with all SRBs. including mods? I've already got a few in mind that I want to use this with.[/QUOTE]

See upthread: http://forum.kerbalspaceprogram.com/threads/139681-1-0-5-alpha-Boosteriferous-SRB-Thrust-Profiles?p=2298265&viewfull=1#post2298265
If you point me at the mods you want support for, I may be able to write .cfgs for them...

[COLOR="silver"][SIZE=1]- - - Updated - - -[/SIZE][/COLOR]

[quote name='DECQ']It's almost what I was looking for, there is only one question, it can only be applied to the solid booster?[/QUOTE]

You could apply the mod to a liquid engine as well, I suppose, if you also set throttleLocked = True, but it doesn't really make physical sense (liquid engines have different kinds of restrictions on throttling and can't have a thrust profile built into them the way solid rockets can). I wouldn't recommend it.

[DECQ]

Energia Rocket reset and is gaining traction as required during the flight as the RD0120 and RD170, in the KSP is virtually impossible (or very difficult) to implement, but the side boosters also eventually lose traction as the SSRB. I tried but did not work...

[Skalou]

Wow , i tried and like it very much!

A really awaited feature to (try to ) compete with the aspargarus,

I used  also "Engine Thrust Controll V2" but without a modifiable in game thrust so not easy to fine tune in game (honestly i only paremeters 2x with it),

your plugin also add this kind of stockalike progression and limitation, i like!

Only thing is missing for me, the caracteristics to be taken in account for the thrust reading in KER.

So congratulation and thank you!

What are your plans for the future?

 

Edited December 1, 2015 by Skalou

[Kolago]

I like that someone finally picked up this SRB Problem in KSP. Thanks!

But I have some hopefully constructive suggestions:

I don't like the segment idea. In the real world propellant grain (the shape of the solid fuel inside the booster) stretches over the ‎whole length of the booster. All of the exposed solid fuels burns in the buster over the the ‎whole length.

There is no instant change in thrust. See here: http://digitalvideo.8m.net/Rocketry/PropellantGrains.gif

The basic idea for KSP is to use the TechTree for more complex SRB grain profiles. Giving the player more options over time. This allows a general MM config over all SRBs in the game including SRBs from Mods.

The GUI complexity can be reduced to right click the SRB to open the context menu and select the profile.

Further reading for people with math background:

Solid propellant grain geometry design, a model for the evolution of star shaped interfaces

http://dare.uva.nl/cgi/arno/show.cgi?fid=200147

Grain Design Program

http://www.aedelectronics.nl/gdp/gdp.htm

But for KSP its better to keep it simple with some grain profiles (thrust profiles) to chose from.

For getting started I can see two simple start and end thrust percent sliders.

Edited January 5, 2016 by Kolago

[soundnfury]

Boosteriferous 0.2.0 released - near-total rewrite for KSP 1.1.

The profiles have been greatly simplified, they now start at full thrust and the user chooses when they throttle down and by how much.  This is for two reasons:

1. that's a much easier thing to turn into a FloatCurve
2. the old way made people think I didn't know how SRBs work, partly because of the unfortunate choice of word 'segments'.

Only lightly tested; I await the inevitable flood of bug reports with, uh, eager anticipation.  Or possibly the other thing.

[Skalou]

Nice to see this mod' updated!

thank you to share it

however i don't like the new system ( after a few try it is just constant full thrust during a certain proportion of fuel and then reduce it for a 2nd thrust value ?) it is far less usefull IMO, we can't throttle it up after max Q?

an idea of what could be really great:

https://www.reddit.com/r/KerbalSpaceProgram/comments/2jwc28/mod_idea_solid_fuel_thrust_profiles/

this and the gameplay integration of your (old) boosteriferous (number of segments/points, price, etc...) and it could be perfect for me.

of course it's just a suggest, and you ride your mode as you want.

 

 

[soundnfury]

5 minutes ago, Skalou said:

however i don't like the new system, it is far less usefull IMO, we can't throttle it up after max Q?

I am planning to add more profile types in the next version (this release was just a quick 'get something out the door for 1.1').  As well as the current 'step' profile, there will probably be 'linear' that ramps down smoothly from start to end, and then some two-part profiles that allow you to throttle back up after max Q.  However, there won't be anything quite as complex and customisable as the old version of this mod had, let alone the 'draw a graph' in the concept you linked.  Part of that is for UI simplicity reasons (I'm not great at writing GUIs), and part because of burn time calculations (I have to be able to integrate the reciprocal of the thrust curve so I can put an appropriate number in maxThrust).

There will be gameplay integration of this new system, the more complex profiles will cost more and possibly require tech unlock.

[Skalou]

Nice, i will follow it with attention!

unfortunatelly i have 0 skill in coding,

but maybe SRB Variable Thrust Limiter  from Crzyrndm  could help you?

and for the UI of the curve in game :

 

[soundnfury]

1 minute ago, Skalou said:

and for the UI of the curve in game :

 

Yeah, I saw those.  Unfortunately, like I said, I can't allow arbitrary FloatCurves, because I have to be able to integrate the burn times.  And I don't fancy writing code for algebraic integration of the reciprocals of arbitrary Hermite polynomial splines bozhe moi.

So I'm limiting to piecewise linear functions.  Much easier to integrate

[Skalou]

Oh ok, i missunderstood you previous post i think,

but i agree that some multi-"segments" of linear ramp/slope (like in the image i posted) could be far enought and much easier for the player ( and to you! ) to deal with than a strange float-curve,

[soundnfury]

Boosteriferous 0.2.1 released - adds a wider variety of thrust profiles, with technology unlock requirements.  Also fixes the Thrust Termination Ports which were broken in 0.2.0.

[linuxgurugamer]

Does this work for 1.1.3?

Would you mind if I add it to CKAN?

[linuxgurugamer]

27 minutes ago, linuxgurugamer said:

Does this work for 1.1.3?

Would you mind if I add it to CKAN?

I just compiled this for 1.1.3

I had to make a couple of changes.  Also, I don't think you should include all the DLLs in both the github AND in the mod itself

Let me know if you want me to push them back to you

[linuxgurugamer]

1 hour ago, linuxgurugamer said:

I just compiled this for 1.1.3

I had to make a couple of changes.  Also, I don't think you should include all the DLLs in both the github AND in the mod itself

Let me know if you want me to push them back to you

@soundnfury I forgot to tag you in my messages

[soundnfury]

On 24/08/2016 at 2:16 PM, linuxgurugamer said:

I just compiled this for 1.1.3

I had to make a couple of changes.  Let me know if you want me to push them back to you

Please do send me a PR on github.  I'll try and make an "official" release for 1.1.3 "soon", if I can find the time.

And, yeah, the src/lib/ stuff should be .gitignored, that was a mistake.  (But the mod download itself doesn't contain them, what are you referring to here?)

[linuxgurugamer]

1 minute ago, soundnfury said:

Please do send me a PR on github.  I'll try and make an "official" release for 1.1.3 "soon", if I can find the time.

And, yeah, the src/lib/ stuff should be .gitignored, that was a mistake.  (But the mod download itself doesn't contain them, what are you referring to here?)

They came in when I cloned the repo.

I'll upload my changes this evening.

[linuxgurugamer]

13 hours ago, soundnfury said:

Please do send me a PR on github.  I'll try and make an "official" release for 1.1.3 "soon", if I can find the time.

And, yeah, the src/lib/ stuff should be .gitignored, that was a mistake.  (But the mod download itself doesn't contain them, what are you referring to here?)

PR done.

I also updated the .version file to 1.1.2, you will need to update the ksp-avc site to match:x

 

For anyone who wants, here is a version for 1.1.3:  https://github.com/linuxgurugamer/boosteriferous/releases/tag/1.1.2-beta

Edited August 26, 2016 by linuxgurugamer
Updated with github link