[1.3.1] Ferram Aerospace Research: v0.15.9.1 "Liepmann" 4/2/18

[ferram4]

@icecubecookie: Oh, I see what's happening. Okay, yeah, that's somewhat minor, but is a really easy fix. I will address it for the next release.

@Jovus: Already found and and I, too, am deeply annoyed by it. I think it will be a simple fix though.

@TheReaper: Yes, that is normal. FAR removes the arrow because the arrow has no meaning at all and it confused people when they went to use it for rocket building.

@Everyone arguing over +AoA control should be which direction: Figure out something that makes sense and I'll change it if need be. Current logic is that setting it to positive AoA causes the control surface to deflect to increase its local AoA, but that can change if need be.

[DaMichel]

Awesome, this should make my marginally stable aircraft a bit easier to fly

I played a bit with the AoA setting already. I found that it can make a plane more statically stable but it will still be dynamically unstable. My test plane was pretty much uncontrollable ... until i used the pitch dampener! With this thing engaged it became a whole different kind of flying, very smooth and very maneuverable (with joystick).

A little feature suggestion @Ferram: It would be so cool if we could store the flight assist settings in the craft file. Not sure how exactly this should work. Maybe have a "copy settings" button in the flight gui. And in the editor add a "paste settings" button to every command module.

[AccidentalDisassembly]

@icecubecookie: Oh, I see what's happening. Okay, yeah, that's somewhat minor, but is a really easy fix. I will address it for the next release.

@Jovus: Already found and and I, too, am deeply annoyed by it. I think it will be a simple fix though.

@TheReaper: Yes, that is normal. FAR removes the arrow because the arrow has no meaning at all and it confused people when they went to use it for rocket building.

@Everyone arguing over +AoA control should be which direction: Figure out something that makes sense and I'll change it if need be. Current logic is that setting it to positive AoA causes the control surface to deflect to increase its local AoA, but that can change if need be.

Any luck with the TweakScale stuff?

[mardlamock]

Am i the only one getting some ridiculous aerodynamic effects when crossing the 200m/s mark? Every plane i ve flown just flips upwards and enters into an uncontrollable spin for no apparent reason

[Starman4308]

Am i the only one getting some ridiculous aerodynamic effects when crossing the 200m/s mark? Every plane i ve flown just flips upwards and enters into an uncontrollable spin for no apparent reason

Very much sounds like you've got center of lift/pressure in front of center of mass (screenshots would help). If you haven't seen it before, I strongly recommend reading this guide to spaceplane design.

[Hodo]

Am i the only one getting some ridiculous aerodynamic effects when crossing the 200m/s mark? Every plane i ve flown just flips upwards and enters into an uncontrollable spin for no apparent reason

Yep sounds like you have to much pressure at the front of your craft, or your CoL is in front of your CoM, either is bad.

[Xgkkp]

Very much sounds like you've got center of lift/pressure in front of center of mass (screenshots would help). If you haven't seen it before, I strongly recommend reading this guide to spaceplane design.

Awesome, I just came to this thread to find something exactly like this; I can't seem to design a plane to save my life (or Bob's, at least)

[mardlamock]

It doesnt seem to be that IMO, ive been playing with FAR for a long long time but this is the first time this ever happens to me. http://imgur.com/ImGLC39,iQ4uXYV,dqgCrvU,wniQcX7,asBQ6qk,fIOXU4C,6GyDrsj#1

[ferram4]

@AccidentalDisassembly: Haven't made any progress on that, sorry.

@mardlamock: I will need a full output_log.txt, or I can't help you. You should also try updating to v0.14.4; support is always void for the older versions of FAR.

Now, this is a bug that has been reported for Senshi's win64 fork... you wouldn't be violating his request to not bother me with support requests for his fork, would you? It's not like anyone using my version of FAR, even the ones that have manually removed the win64 check have ever run into that bug, so it sounds a lot like you're trying to get support for an unsupported KSP build and for a fork of my project. You wouldn't be trying to do that, now would you?

[mardlamock]

@AccidentalDisassembly: Haven't made any progress on that, sorry.

@mardlamock: I will need a full output_log.txt, or I can't help you. You should also try updating to v0.14.4; support is always void for the older versions of FAR.

Now, this is a bug that has been reported for Senshi's win64 fork... you wouldn't be violating his request to not bother me with support requests for his fork, would you? It's not like anyone using my version of FAR, even the ones that have manually removed the win64 check have ever run into that bug, so it sounds a lot like you're trying to get support for an unsupported KSP build and for a fork of my project. You wouldn't be trying to do that, now would you?

Who? Me? Impossible, i would never try such a thing! Ehhmm it seems the problem has solved itself, no need to get violent or anything. Now, would you mind if i asked you how you calculate the moments of inertia? Im building a model for a rocket's movement with atmospheric drag lift and everything but i cant get anything done with orientation without the moments, and for the time being i have no idea how to calculate them. Would you mind referring me to some book or anything i could use?

[ferram4]

@mardlamock: Hmm... okay, you didn't do that, and don't let it happen again. For reference, that is exactly why I wasn't thrilled with Senshi's fork of FAR; I have to keep track of any bugs in my version and his version.

Anyway, so the basic definition of for a moment of inertia requires an integral of each unit of mass and its distance^2 to the reference point... not something you want to do manually. Fortunately, each part in KSP has its principal moments of inertia stored and a transform or quaternion describing the orientation of those principal moments wrt the part itself. If you want to get the total moment of inertia for a vehicle in KSP, go through each part, transform the principle moments of inertia for each part into a general inertia tensor aligned with the axes you care about, and then add that to the total inertia tensor, and then use the parallel axis theorem to account for the offset in the reference position of the part inertia tensor to where you're measuring your overall inertia tensor.

FAR has some code that does this in FAREditorGUI.cs if you don't care about getting into GPL code. Alternatively, I built most of that up with my nose buried in Chapter 9 of Orbital Mechanics for Engineering Students, Howard D. Curtis, 2e, which is a chapter on rigid body dynamics for analyzing the behavior of satellites. Any textbook with a focus on rigid body dynamics should suffice though.

[mardlamock]

@mardlamock: Hmm... okay, you didn't do that, and don't let it happen again. For reference, that is exactly why I wasn't thrilled with Senshi's fork of FAR; I have to keep track of any bugs in my version and his version.

Anyway, so the basic definition of for a moment of inertia requires an integral of each unit of mass and its distance^2 to the reference point... not something you want to do manually. Fortunately, each part in KSP has its principal moments of inertia stored and a transform or quaternion describing the orientation of those principal moments wrt the part itself. If you want to get the total moment of inertia for a vehicle in KSP, go through each part, transform the principle moments of inertia for each part into a general inertia tensor aligned with the axes you care about, and then add that to the total inertia tensor, and then use the parallel axis theorem to account for the offset in the reference position of the part inertia tensor to where you're measuring your overall inertia tensor.

FAR has some code that does this in FAREditorGUI.cs if you don't care about getting into GPL code. Alternatively, I built most of that up with my nose buried in Chapter 9 of Orbital Mechanics for Engineering Students, Howard D. Curtis, 2e, which is a chapter on rigid body dynamics for analyzing the behavior of satellites. Any textbook with a focus on rigid body dynamics should suffice though.

Thanks man!

[kerbon]

Hello!

Has anyone encountered this problem ? Right after loaded the plane on the runway, it "spins" on its back wheels. This isn't a big problem with lightweight planes but with big ones, like B9 stampledon, the engine explodes.

I have B9 Aerospace 5.2.6 and FAR 0.14.4. It seems this problem appears when both mods are in use.

This is a drone provided by B9. For stock spaceplanes, the problem doesn't appear. And if I remove FAR, the drone is loaded fine. Can you help me please ?

[Wanderfound]

Hello!

Has anyone encountered this problem ? Right after loaded the plane on the runway, it "spins" on its back wheels. This isn't a big problem with lightweight planes but with big ones, like B9 stampledon, the engine explodes.

I have B9 Aerospace 5.2.6 and FAR 0.14.4. It seems this problem appears when both mods are in use.

This is a drone provided by B9. For stock spaceplanes, the problem doesn't appear. And if I remove FAR, the drone is loaded fine. Can you help me please ?

http://i.imgur.com/foxkHFq.jpg

FAR allows the adjustment of wing weight/strength; default FAR wings are considerably heavier than stock wings (but can be adjusted to be much lighter, at a cost in durability). The change in wing weight has shifted the CoM behind the landing gear.

As a rule of thumb for the wing mass/strength tweakable: .25 is light but very fragile (like ye olde FAR wings, before the mass tweakable was introduced), .5 is tough enough for anything that a sensible pilot should throw at it, 1.0 is overkill unless you're planning high-G aerobatics at treetop altitudes.

[kerbon]

Thank you for your help!

Is there a GUI tool to tweak that value ? Thanks to https://github.com/ferram4/Ferram-Aerospace-Research/commit/2bfd6cbaf554054a2b9338bc5a1d6c7af1f7b2b3 , it seems

[Guest]

Would that be possible to add a feature to disable the strength adjustment? It's mostly for things like Realism Overhaul, where the winglets concerned are simulating real parts, meaning the mass shouldn't be adjustable. It's not a huge problem now, but I need that feature before I start doing either Shuttle or Buran.

[kcs123]

Thanks a lot for this mod, it really helps to understand how and why planes actually flies. I have small suggestion/feature request to improve it.

It seems that lot of newcomers to mod forgot to check craft behaviour with negative AoA, like praise the suuun did in his picture or like I did on this picture in attempt to explain my craft designs.

If you set default AoA values for static analysis like -25 to +25 AoA, I think that less people will wondering what is wrong with their craft designs.

Also, since each craft design has it's own limits when comes to maximum negative and positive AoA and safe roll degree, can you make some additional item similar to firespitter trim control. That item should be nothing more then variable value container for min/max AoA, roll and yaw bounds.

Purpose for this item will be to use those values for FAR flight assistance, when craft is loaded to use values in that container instead of global settings for FAR flight assistance. Also other autopiloting mods like MJ or kOS will be able to read those values. That can help autopilot modders to make better autopilots that will not going to crash craft when it is used along with FAR mod.

Even better, it could be embeded within command modules, so it does not require additional part, but it should be done in a way that if someone uninstall FAR mod it doesn't break whole craft file.

Don't know how hard it is to make something like this, but thanks for your time if you put it in consideration for future updates.

[etheoma]

Ok on RSS I'm having a problem with all my ship having a rapid unplanned disassembly when I try and descend this is with

Aerodynamic Failures Disabled

Anyways someone was saying in the RSS thread I should try editing the Temp curve values but I have no idea how do to that could anyone tell me how that is done.

[Master Tao]

@etheoma:

Temperature curves are a Deadly Reentry feature. If you hit F3 after your ship is destroyed, you'll probably find that parts were destroyed due to overheating, so you'll need to ask in the DRE thread. In particular, read the first post and the last few pages since there's been some discussion about how to adjust temperature curves.

[ferram4]

@kerbon: Right-click on the wing.

@Dragon01: It is certainly possible, but I'd rather not; I already have plans to scrap the current wing code entirely, I don't want to put more work into it when it's all going to get trashed anyway.

@kcs123: The default values stay where they are; anyone running into problems at negative AoA should be smart enough to ask the sim to run it at negative AoAs, not expect it to read their minds.

FAR already goes slightly outside scope with the control systems it provides; any more work on parameters for that should be done inside the dedicated autopilot /control system mods, not FAR itself.

@etheoma: Dunno, RSS is the mod that changes the temperature curve of planets. FAR doesn't change the curves, it just reads off of them. Ask how to change it in the RSS thread, there's probably a config somewhere to modify.

[etheoma]

@etheoma: Dunno, RSS is the mod that changes the temperature curve of planets. FAR doesn't change the curves, it just reads off of them. Ask how to change it in the RSS thread, there's probably a config somewhere to modify.

MORE QUESTIONS MISTER!!! FAR does apply them like a curve right so as I pass from one entry to the next say 0 - 2km it doesn't just change instantly when I get to 2km

because if not I can just break up them up into further gradations, if it already does that automatically then I'm screwed.

Well it only seems to be ripping apart the new Mk2 parts porbably do to weak connections between the parts.

I'm am breaking up in the atmos at like 105 - 92km at 7200ms to 6000ms in RSS Eve which is less than 0.001 frac SL density with aerodynamic failures disabled but I'm not even getting the high dynamic pressure warning anyway.

And even with high dynamic pressure warning your not likely to break up by the joints on something breaking usually. unless your in like kerbin sea level atmos travelling at 400ms and then you pancake.

And I am able to go though Kerbins atmos at over 10 times the air density and I will be fine as long as I don't go crazy with the AOT

And there is no real way to slow down much more because the air densities are so low that not even a bunch of aerobreaks wont do it... Also I dislike using aerobreaks up that high at those velocities because its not realistic in the slightest.

Also I keep getting random kicks which will always push my craft to the left and slightly up. Even when using B9 parts which have stronger connections in general.

I know its probably a problem with RSS because I wasn't having these problems before but people in the forum keep telling me I'm going to fast when I know full well at those speeds and air densities you shouldn't be falling apart especially with air-dynamic failures disabled and an angle of attack not exceeding 20 degrees and usually more like 5 - 10 degrees.

TL;DR

Basically what I need from you is to tell me no 7200/ms is too fast in a atmos of 0.001< frac SL density ridiculous speeds stop being stupid or say they should be fine so I can get some help on the RSS forum, because one of the dev's is refusing to help because he says that I'm going to fast even though I have shown him that on RSS kerbin you can go WAY WAY WAY beyond what I was doing on Eve.

Thank you for for your help I hope...

Edited November 30, 2014 by etheoma

[Hodo]

@Dragon01: It is certainly possible, but I'd rather not; I already have plans to scrap the current wing code entirely, I don't want to put more work into it when it's all going to get trashed anyway.

Can you give us some insite on what will change on the wing code? How will it affect current designs? Will it require a complete redesign of existing craft?

I mean I would be really upset at losing this gem of a craft, my Mirage 2000 knock off SSTO.

I mean it handles like a dream, flies easier than anything I have ever made, and it was all accidental.

On a more serious note, I have noticed another minor bug. Not sure what is causing it, tried removing FAR then reinstalling with the latest build on Github. But after each flight the CoL shifts way back, almost to where I imagine the CoL shifts to at hypersonic speeds. But as soon as I tap the procedural wing or take off a control surface and put it back it updates back to where it should be.

But it has no affect to the craft in flight or in the FAR diagnostic graphs or charts.

Oh one more request..... do you have any information for real aircraft like a F-16 or Mig-21 in the FAR diagnostic graphs and charts? I would love to see what a highly menuverable aircraft that is unstable naturally looks like compaired to a stable aircraft that doesnt need fly-by-wire controls to keep it in the air.

[NathanKell]

etheoma: what you are consistently failing to realize is that the sea level density of Venus is not the sea level density of Earth. 0.1% of 110 is a lot more than 0.1% of 1.225!

Edited November 30, 2014 by NathanKell

[Hodo]

And B9 Aerobreaks are still OP.

B9 air brakes are not OP right now. If I just place two of the larger ones on a decent sized craft, they barely slow it down. I have had 6 of them on one craft that weighed in at a hefty 60 tons on re-entry it wouldn't slowdown, it barely slowed down for landing at a 3deg glide slope.

[camlost]

Oh one more request..... do you have any information for real aircraft like a F-16 or Mig-21 in the FAR diagnostic graphs and charts? I would love to see what a highly menuverable aircraft that is unstable naturally looks like compaired to a stable aircraft that doesnt need fly-by-wire controls to keep it in the air.

The “AoA†feature is a simple simulation of a fly-by-wire feature, and FAR charts take account of it. So, an unstable aircraft would seem unstable, but becomes stable when you tune the AoA right