Advanced SRB dev [test version 0.7 released]

[kujuman]

Latest News

I've published v0.7 Alpha. There is still a lot more to be done before a general release, but I figured I need some feedback, in particular about the UI. I don't think it's particularly buggy (except the launch clamps), but who knows what mods may make it misbehave. By downloading and using v0.7 Alpha you should understand that it is still a work in progress so you should create backups of your existing save files or start new ones.

For general information on how to use the pack visit the general release thread, which I have linked in my signature.

The link should be at Advanced Solid Rocket Boosters

This version requires blizzy78's Toolbar mod http://forum.kerbalspaceprogram.com/threads/55219 (included) and makes use of ModuleManager by ialdabaoth and sarbian http://forum.kerbalspaceprogram.com/threads/55219

Source linked below

Please list any bugs you find, including steps you did to create them. I am still in the process of creating a burn profile for an entire stack at once, but that'll be for later, I wanted to get a release out tonight; you have to set the burn profile for each segment right now.

0.7 Alpha c 2014 All Rights Reserved.

============

This thread will serve to inform/ask the community about the overhaul of the Advanced SRB mod from v.6.

The original goals of the AdvSRB mod were:

to create stackable SRBs

to allow custom burn profiles

to give SRBs some respect

Since the initial release of AdvSRB, there have been two significant improvements to SRBs: procedural SRBs and tweakables. Even with these, I still feel that there is a gap for improved SRB functionality, which is why I'm continuing development.

Major changes from AdvSRB v.6

Burn times are now linked to nozzles, not segments.

Added primitive delta-v page to help while building rockets.

Primitive heat generation (based on burn rate).

Added rocket shake: thrust from AdvSRBs will cause a bit of wobble, but not too much.

Added thrust surging: thrust (Isp actually) will cycle from higher to lower to higher fairly rapidly. Make sure you've strutted everything.

Github https://github.com/kujuman/ksp-ksf-advSRB

Edited May 7, 2021 by Snark
Link to defunct website removed by moderator

[Space_Kraken]

Yay! Now I can have my perfectly tuned Ariane 7 (or whatever it is now-a-days)!

[BLUAV8R]

Love it! will help as tester if needed

[kujuman]

Love it! will help as tester if needed

Ok. I'd be interested in feedback about the GUI initially, so when I get a little more progress on it I'll get a test copy ready for release.

[Space_Kraken]

I want to be a tester also.

[MrHappyFace]

And me, this sounds like a much needed addition to SRBs

[kujuman]

Got the graph generator code working again (wasn't too much of a hassle). The scattered blips are a result of the thrust variation feature. The first image has a variation factor of .3, the second is with a variation factor of .05.

The blue is the mass of the segment + fuel (scale at left)

The cyan is thrust (scale at right)

The yellow is extra thrust (thrust - mass * 9.81m/s)

I expect a test release this weekend.

[montyben101]

HOLY **** that is amazing!!!!!! Will it work with mod SRBS like the tiberdyne ones and kw rocketry ones?

[kujuman]

HOLY **** that is amazing!!!!!! Will it work with mod SRBS like the tiberdyne ones and kw rocketry ones?

I'm planning on creating/releasing Module Manager files for some of the more popular packs, as well as the stock SRBs (except the seprtron and other similar motors. No need to complicate things ).

I intend to have a MM file for at least stock and KW (as it's the only pack with SRBs I currently use) done when I release .7 (the first major redo) of the mod.

All that needs to be done is take out the ModuleEnginesFX and replace as such.

MODULE
{
name = KSF_SolidBoosterSegment
topNode = top
endOfStack = true
GUIshortName = LargeBooster
thrustVariation = .05
}
MODULE
{
 name = KSF_SBNozzle
 atmosphereCurve
  {
     key = 0 250
    key = 1 230
  }
 thrustTransform = thrustTransform
 effectGroupName = running_closed
 resourceName = SolidFuel
 topNode = top
}

[NathanKell]

This looks awesome! Even better than Engine Thrust Controller for simulating solids. Given that this, too, will be writing to thrust, (and thus there can be only 1, I think), could you also do thrust curves? I..e. when sum(amount_of_SF_available) / sum(maxAmount) = x, thrust should be y% of stated maxThrust.

[kujuman]

Given that this, too, will be writing to thrust, (and thus there can be only 1, I think), could you also do thrust curves? I..e. when sum(amount_of_SF_available) / sum(maxAmount) = x, thrust should be y% of stated maxThrust.

I'm not sure exactly what you mean by thrust curves (if it's any different than what I'm using currently. I have thrust curves based on time, not % of propellant expended), but I'll explain what currently happens:

1. Two PartModules, Nozzle and Segment. Nozzle is used similarly to a LFE, Segment to a LF tank.

2. Nozzle contains atmo curve for Isp, propellant type, and an ignition T+ counter. Pretty basic really. Segment basically stores an animation curve with keys containing Time, MassFlow (in tonnes per second), and in and out tangents. Each segment's burn profile can be edited in the VAB or SPH.

3. The nozzle part creates a list of connected parts containing a Segment (using the topNode name). This can include itself (for one part boosters)

4. On ignition, and thereafter, the Nozzle queries each Segment in the connected parts list to get MassFlow(t). It then subtracts that resource mass from the Segment and sums the MassFlows from all connected Segments.

5. Nozzle then calculates thrust (constant flow, varying Isp makes thrust vary) and applies it.

There is no set limit on the thrust a single nozzle can accommodate, and one can stack booster segments as high as one would like (well, limited to 250 times to help check against an infinite loop).

There is tons more info at the release thread, linked in my sig.

[sgt_flyer]

Do you plan to add advanced nozzles ? Like gimballed nozzles / assymetric thrust ones (for Atlas V assymetric boosters placement style) - maybe even an angled multi nozzle one for escape towers - i don't like how the stock escape tower works

Could even do with a vacuum nozzle / pill shaped solid fuel tank, for those who would want to build a solid fuel upper stage

[kujuman]

added a link to the first test version .6.1 on the first post. There's still a lot more work before general release. Be advised that unlike (pretty much all) other mods, these parts are somewhat designed to break apart and explode if you push them too hard.

Do you plan to add advanced nozzles ? Like gimballed nozzles / assymetric thrust ones (for Atlas V assymetric boosters placement style) - maybe even an angled multi nozzle one for escape towers - i don't like how the stock escape tower works

Could even do with a vacuum nozzle / pill shaped solid fuel tank, for those who would want to build a solid fuel upper stage

All of the boosters have in the pack currently have gimballing, including the stock SRBs if you have ModuleManager. I'm not intending to create a bunch of parts for this plugin, partly because I'm pretty slow and partly because I'm not nearly as good as others on here.

I'm not sure I want to get upper stages worked on until I get some way to spit out delta-V for the user, but it shouldn't stop anyone else from doing it.

[kujuman]

Update time!

I'm refactoring the nozzle code yet again to be derived from ModuleEngines. The impetus for this was wanting to make AdvSRBs play more nicely with other mods, such as any center of thrust or auto gimbal mods. I don't think that this will help much with some of the mods which make bigger assumptions about fuel flow and need a maxThrust estimate, like MechJeb or Engineer, but it's still a step in the right direction.

The testing I've done shows that almost everything is still working as designed except that I broke the effects system again. What a shock.

This is something I've wanted to do for a long time, so it's really rewarding seeing it working, and in less time than I thought it would take. With .24 now in experimentals, I may actually get .7 released to coincide with it.

[kujuman]

More updates

Nozzle code is now based on ModuleEnginesFX, so it will natively support (at least, better support) the new effects system. I've also enabled the old effects system to work with it via a bool in the .cfg. So effects are working nicely.

I wrote a MM config for the KW pack and it works nicely with AdvSRBs.

Still want to enable the player to set one thrust curve for the entire stack. It shouldn't be too difficult, but integrating it into the UI nicely will take some thinking.

[ShadyAct]

I'm looking forward to this maturing and eventually becoming a finished product, I like mods that add another layer of realism or complexity for those that want to delve that deep. Do you need people to bug-test this?

[falken]

Hi, this is exactly the mod I want to see as a shuttle enthusiast. I am constantly trying to find the perfect settings for my STS system srbs and this could be it. If I can help with testing that would be wonderful.

[falken]

Okay, I've been fooling around with the settings and I'm still not quite mastering this. Can someone tell me how I can have an SRB stack have more power to start off with, and slowly trail off as my shuttle punches through the atmosphere, and finally around 5 seconds of very little thrust for me to then do an SRB sep?

[kujuman]

Okay, I've been fooling around with the settings and I'm still not quite mastering this. Can someone tell me how I can have an SRB stack have more power to start off with, and slowly trail off as my shuttle punches through the atmosphere, and finally around 5 seconds of very little thrust for me to then do an SRB sep?

I don't have time to answer this directly, but I think this video has an explaination

[falken]

Okay, I have been doing some testing and this still works as intended in .24! Rejoice!

[Ikaneko]

Bit fiddler, you've posted this on every non-updated mod thread I've seen. Please don't cross-thread spam. It's quite annoying.

[kujuman]

~tap tap tap tap tap~

This microphone, is it on? Yes? Yes! And so...

Development is not quite resuming, but it's on the list. Once NavUtils v.5 gets out I'll focus on rewriting this. I think it'll bring lots of compatibility breaking, but I don't think there are so many users that compatibility would be a big issue.

I've learned a lot writing NavUtils, so you can expect:

-Simpler booster configuration process. Configure the burn time for the nozzle, instead of each segment. Interesting note: the reason segments have the burn time embedded in them is from a time before the GUI in the VAB...each segment part came with different burn profiles.

-Support for symmetry in nozzles (this actually may be in there...I have yet to reread the code).

-Better UI, perhaps nicer graphs eventually.

-Support for stock AppLauncher and blizzy78's ToolBar

-An attempt at creating support for Engineer and similar mods

-Changes to/removal of stack disintegration feature.

Possible changes to core functionality, if expected benefits outweigh time spent:

-Basic pressure simulation. Thrust/ISP may be based on nozzle configuration (thanks to mod developer's great expansion of tweakable part configs)

[falken]

Looking forward to it. Do you think you'll be enhancing the nozzle exhaust effects as well? That was the only thing I found was a bit lacking with Advanced SRBs.

[kujuman]

Looking forward to it. Do you think you'll be enhancing the nozzle exhaust effects as well? That was the only thing I found was a bit lacking with Advanced SRBs.

I'll probably use the new SRB effects. Unless you mean something else?

[falken]

Well, the new effects are alright, but there is the KW effects which are crazy good. Even just hotrockets integration would be super.