Come back old ASAS - all is forgiven!

[stupid_chris]

Except for those of us where its NOT holding a heading, not at all. Im not talking about the old days, spinning around, letting go of F right on the mark and just waiting for it to get back there. Starting from no movement, with SAS engaged, on a balanced rocket, with power, in a vacuum, using a command pod with reaction wheels and SAS, using extra reaction wheels, with gimballing engines...and away it drifts when you hit the gas. Its like the SAS is sort of a suggestion, it will usually keep it sort of in the neighborhood, but half an inch off the marker, and floating about is quite a difference when aiming at another planet.

It seems the people who have no problem just can not comprehend that anything could be wrong, we are all lunatics imagining this, or "cheaters" spoiled by mechjeb or too stupid to have the proper parts on our ships.

There is no way Squad intended the control I have now on rockets to be this way, its no way to get anywhere.

Yes, that's something else, I was speaking for his problem only. The other issues where it doesn't work as intended are the ones worrying me. In his case, it's working as intended, but not as he would want it to.

[allmappedout]

This post sums up my feelings about it

1. If you have multiple gimballing engines you can still sometimes get a cascade effect, particularly when the thrust is high. On one of my rockets I built, with a middle skipper and 4 mainsails surrounding it, in order to be able to pull off the gravity turn without unplanned disassembly, I had to disable gimballing on two of the mainsails, otherwise the entire craft flipped out as I moved away from 90deg.

2. When the SAS is providing a significant input into the PID system already (such as a plane that is nose heavy and thus requires a high amount of pitch up), any attempt to correct it seems to forget the previously required pitch up (ie: your input starts back at zero, rather than where the PID controller is currently applying the force). As a result, it's hard to trim the craft with SAS on, as the trim resets that axis, and effectively de-binds it from input control.

TL;DR - it's great, needs tweaking for one or two scenarios. 2 is more of a priority than 1.

[Conzolax]

I did watch it, I saw. I believe it simply doesn't account for CoT and CoM not being aligned for now in vacuum, and that's a valid claim. It should correct that situation. But take a normal lander or anything with those two aligned, and it won't budge a notch while thrusting forward.

Now, this might just be me, but if your CoT and CoM are aligned in a vacuum, your ship wouldnt budge at all, ASAS or no ASAS.

AFAIK the whole point of ASAS is to hold your ship in the direction of your choosing, and try to compensate for a sligtly off CoM/CoT with the control surfaces/gimbal/torque it has available.

Ofc, i might be totally wrong.

Edited July 25, 2013 by Conzolax

[njd80]

For everyone who is having problems, in this video http://youtu.be/-tslKIlAxHQ C7 mentioned the new SAS system in relation to joysticks, and states the need to set deadzones. Perhaps the drift from stable can be attributed to micro-inputs from an ever-so-slightly off center joystick or controller?

[stupid_chris]

Now, this might just be me, but if your CoT and CoM are aligned in a vacuum, your ship wouldnt budge at all, SAS or no SAS.

It is just you, the CoM is a scalar and the CoT is a vector, they can't cancel each other out. What I meant is for the CoM to be on the same line as the CoT, not exactly at the same place. Gimbals wouldn't work if they were overlapped, but you would thrust just fine.

[Temeter]

Yes, that's something else, I was speaking for his problem only. The other issues where it doesn't work as intended are the ones worrying me. In his case, it's working as intended, but not as he would want it to.

Can you please stope with that condescending attitude? The rocket strolling of course and the sas ignoring gimbal or actively adding spin was a rather unusual thing and surely some kind of bug. Starting rockets works quite well most of the time.

In my case it's the same matter of the sas just being unable to hold the heading, as Kerbinson also wrote. The sas stabilizes to some degree, but in fact insufficiently accounts for problems shifting the craft of it's course.

[Tiron]

Yes, that's something else, I was speaking for his problem only. The other issues where it doesn't work as intended are the ones worrying me. In his case, it's working as intended, but not as he would want it to.

Actually it's all the same issue. There's only one, I'm pretty sure. And I'm pretty sure it's NOT intentional.

Some of the old SAS worked the way you describe, the pods because they were supposed to be only a partial version they got free as a demo for the full one, and the avionics because attitude hold would make a plane unflyable. the regular SAS also got modified to act this way sometime in 0.20, presumably to make it work as a rover stabilizer. the ASAS never did.

But more than that? Check this out:

Pre-release demo vid from Chad himself. You'll note there that he starts a rotation on the station, then lets the SAS have it, the same test I was doing, only with a station. It starts off by damping the rotation out, then REVERSES it, and then stops it not where it originally started at, but at the point where he stopped telling it to roll, exactly as I describe.

You're mistaking what was in the old version a kludge to make certain things work with the completely unforgiving old system for a design intention.

Edit: And the only link I can find that you posted is to a thread where a bunch of people are posting partial system info, mostly people who swear it works fine, which isn't really helpful.

[Danger Will Kerbinson!]

From my observation on my wandering SAS is not using engine gimbals at all on my rockets unless its from MY input, but for trying to hold course its only using torque, and seemingly not much of it. Ive watched a lot of launches zoomed right into the bell nozzle, even as my rocket is wildly swinging back from being nudged over into a gravity turn that SAS does not feel I should be doing or something so it does not feel the need to use engine gimballs. It WILL use control surfaces...but they don't seem to do anything when the SAS is using them, they visually move but the swaying will continue. Its a lot like trying to balance a broom on your palm, you can keep it pointing up pretty well, but it requires constant input and its not solid feeling.

[EvilotionCR2]

Could they just bring back the old ASAS as separate part? Everybody would be happy.

[stupid_chris]

Can you please stope with that condescending attitude? The rocket strolling of course and the sas ignoring gimbal or actively adding spin was a rather unusual thing and surely some kind of bug. Starting rockets works quite well most of the time.

It's in my case the same matter of the sas just can't hold the heading, as Kerbinson also wrote. The sas stabilizes to some degree, but in fact insufficiently accounts for problems shifting the craft of it's course.

I must say I'm sorry if you mistook that for a condescending attitude, but it isn't. My tone is neutral.

Also, I wasn't referencing to you, I was talking about Tiron's issue. I agree with you that there is some issues with some people for the SAS behavior, and Kerbinson does seem to have an issue with it not working as intended, so if you are having the same problem as him, then you are including. However, the SAS just keeping on drifting before coming to a stop is it working as intended. Maybe it's not the best behavior, but it's really working as intended, and if anyone wants to change that, the development forums are the best place to do it.

Again, please excuse me if you mistook that comment, no harm was meant.

[Danger Will Kerbinson!]

Tiron, I just watched that vid again....you are right, it does go back to where the buttons were released. His station wobbles back and forth till it gets there. My ships do not do that. What they do is when you release the control it will being to slow but continue for quite a while, it will slow to a stop eventually and stay (sort of) there, there is no spring back at all.

[stupid_chris]

Alright, I can see my help is not appreciated here, I'll just move on to something else. May everyone have a nice day.

[Tiron]

I must say I'm sorry if you mistook that for a condescending attitude, but it isn't. My tone is neutral.

Also, I wasn't referencing to you, I was talking about Tiron's issue. I agree with you that there is some issues with some people for the SAS behavior, and Kerbinson does seem to have an issue with it not working as intended, so if you are having the same problem as him, then you are including. However, the SAS just keeping on drifting before coming to a stop is it working as intended. Maybe it's not the best behavior, but it's really working as intended, and if anyone wants to change that, the development forums are the best place to do it.

Again, please excuse me if you mistook that comment, no harm was meant.

Given that I just posted a dev video showing it working the way *I* describe, I would really like it if you could post a link to where an actual dev says the behavior you state is the intention.

Because so far as I can tell, the problem I noted is the root cause of every problem everyone else is talking about as well. And even on mine, actually WATCH THE VID. It doesn't just stop the motion. It does, in fact, very briefly REVERSE THE CONTROLS right after coming to a stop, and briefly rotate back the other way. Only for a second or two at most(more like a fraction of a second), but it DOES reverse. If it were simply trying to damp motion it wouldn't need to do that.

Edited July 25, 2013 by Tiron

[Temeter]

I must say I'm sorry if you mistook that for a condescending attitude, but it isn't. My tone is neutral.

Also, I wasn't referencing to you, I was talking about Tiron's issue. I agree with you that there is some issues with some people for the SAS behavior, and Kerbinson does seem to have an issue with it not working as intended, so if you are having the same problem as him, then you are including. However, the SAS just keeping on drifting before coming to a stop is it working as intended. Maybe it's not the best behavior, but it's really working as intended, and if anyone wants to change that, the development forums are the best place to do it.

Again, please excuse me if you mistook that comment, no harm was meant.

No, it's obviously my fault if i mistook the comment. Sorry for that, the heat is slowing down my brain...

My problem is, that the drifting doesn't stop, it just continues or gets actually faster. I think it's because the sas doesn't apply enough force to counter the movement. It's just weird, how it seems works for others.

[Danger Will Kerbinson!]

I had forgotten how easy that rocket controls in his vid Tiron, it does swing back a tiny bit as he does his gravity turn...but he just dumped it over...and the spring back is far less than I get when moving it very slowly and gently. It seems if I try to move more than a few degrees ahead of the prograde mark it will not be able to hold anything close to that new heading, plus I get all this yaw wandering when Im only pitching.

[ComradeGoat]

Edit: And the only link I can find that you posted is to a thread where a bunch of people are posting partial system info, mostly people who swear it works fine, which isn't really helpful.

Yes. When some of us are trying to explore a bug that's affecting us, a bunch of people shouting, "it works OK for me" are not being entirely helpful. If it works for you I'm glad, but it's not working for me, and I've posted video proof.

[Tiron]

No, it's obviously my fault if i mistook the comment. Sorry for that, the heat is slowing down my brain...

My problem is, that the drifting doesn't stop, it just continues or gets actually faster. I think it's because the sas doesn't apply enough force to counter the movement. It's just weird, how it seems works for others.

Well it DOES work to a degree, just not quite...right. It's a bit fiddly and difficult, but you can get where you want to go if you're patient enough.

Or just use Mechjeb's Killrot, which is basically the same as the old SAS, except it has control override and automatically sets the new target attitude to be the point where you stopped using the controls.

The new SAS is much more efficient and dramatically less wobbly, but at the moment seems to be having trouble holding an attitude.

[Crusher8000]

I don't mind the weaker SAS, it gives me something to do thorough the whole flight.

[Tiron]

I had forgotten how easy that rocket controls in his vid Tiron, it does swing back a tiny bit as he does his gravity turn...but he just dumped it over...and the spring back is far less than I get when moving it very slowly and gently. It seems if I try to move more than a few degrees ahead of the prograde mark it will not be able to hold anything close to that new heading, plus I get all this yaw wandering when Im only pitching.

Even slightly broken, it's still a LOT easier with the new SAS than it used to be. I haven't flown more than a craft or two to orbit manually since I stopped playing the 13.3 demo and bought 0.16, and I managed it pretty okay with the Kerbal-X all stock. Minus my bad, rusty piloting caused mostly by my attention wandering (I have ADHD, it does that).

[Pixel of Life]

Tiron, the problem is that it was programmed to function this way. It's literally meant to be this way. ASAS is totally gone, going back to the target is one of the things that went along with it, because it added trouble. The goal of the SAS is to hold the heading, and it does it. Once your craft will have stopped moving, try thrusting forward. You won't move at all. And that is the goal. Stop your rotation, then hold the heading you are at. That's the two things the SAS module does. Unlike the ASAS who went: stop rotation, go back to when I was activated, go back to when I was activated, go back to... You get the pattern? It's not an error, that's blatantly what it's meant to be like.

EDIT: Also, it's not applying maximum force to not shred your craft apart. If you had a large craft, strong rotational forces could cause breaks. The goal was to make it smoother.

For more information on how it works, read this.

But it doesn't hold the heading! I've got an SSTO spaceplane that's very well balanced, and with an LV-N for interplanetary burns - it doesn't use the gimballing nozzle at all! It's impossible to do accurate burns because it's always drifting off the maneuver node marker. I have to really fight the plane to keep it aligned, and even then there's a high chance of screwing up.

[Shyanmar]

I have absolutely no problems with the new SAS. Where pretty much all of my planes pre-0.21 were a bitch to fly unless I used ASAS to cement the heading to a spot (which didn't always work and if it did always nearly tore the plane in half), which is definitely not the way it should have to be - it's a goddamn plane, after all - now almost every plane I build handles very nicely. Even if I oversteer and get into a spin the recovery speed is amazing.

The only thing where it currently annoys me is rockets. The large ASAS supposedly works as usual, at least if one goes by its description, but even with reaction wheels added and additional decoupler stabilization my larger rockets usually wobble like hell, especially on takeoff it's extremely hard to keep it pointed upwards. Once I get to sufficient altitudes for a gravity turn the problem minimizes, but until then it's hell. I can still get 100t payloads into a very low orbit, but it's a huge hassle every time. Same goes for smaller rockets, but they're usually easier to keep under control. I think we basically need two versions of SAS - one for planes and one for rockets.

[Tiron]

I have absolutely no problems with the new SAS. Where pretty much all of my planes pre-0.21 were a bitch to fly unless I used ASAS to cement the heading to a spot (which didn't always work and if it did always nearly tore the plane in half), which is definitely not the way it should have to be - it's a goddamn plane, after all - now almost every plane I build handles very nicely. Even if I oversteer and get into a spin the recovery speed is amazing.

The only thing where it currently annoys me is rockets. The large ASAS supposedly works as usual, at least if one goes by its description, but even with reaction wheels added and additional decoupler stabilization my larger rockets usually wobble like hell, especially on takeoff it's extremely hard to keep it pointed upwards. Once I get to sufficient altitudes for a gravity turn the problem minimizes, but until then it's hell. I can still get 100t payloads into a very low orbit, but it's a huge hassle every time. Same goes for smaller rockets, but they're usually easier to keep under control. I think we basically need two versions of SAS - one for planes and one for rockets.

The latter problem is the one we're talking about, more or less. For spaceplanes it's MUCH better, because it allows control overrides without fighting them.

Effectively the way it's working now is very similar to the way the old avionics nosecone worked, only better. So yes, it's great for planes.

For rockets...not so much, because it won't hold an attitude. Especially when trying to execute precise maneuvers in space it's very difficult to use.

[Nicok]

To put it simply,

New SAS (IAS) works neartly perfectly for planes and spaceplanes.

On the other hand, it's like flying without IAS since you fly rockets. Even a little misalignement of CoM (which worked fine before) leads to loosing control / permanent drift.

Simple designs (i quite flying 2.5m for a long time) with maximum of 50 parts go crazy or inclinaison above 2°... it's really like flying without IAS.

I'm kind of disapointed since the videos by C7 was awesome... I feel like it's not what was showed...

[Tiron]

To put it simply,

New SAS (IAS) works neartly perfectly for planes and spaceplanes.

On the other hand, it's like flying without IAS since you fly rockets. Even a little misalignement of CoM (which worked fine before) leads to loosing control / permanent drift.

Simple designs (i quite flying 2.5m for a long time) with maximum of 50 parts go crazy or inclinaison above 2°... it's really like flying without IAS.

I'm kind of disapointed since the videos by C7 was awesome... I feel like it's not what was showed...

In a way it's not. Those videos showed a system that worked like Mechjeb's Killrot has for as long as I can remember: Controls override it, and when you let go of the controls, it sets that to the new attitude hold point and holds it there until you move again (or turn it off).

What we got is a system that works like the old Avionics Nosecone or Pod SAS: It merely damps movements, and doesn't try to hold a particular attitude at all.

[Rosarium]

not really. IAS works the same with both spaceplanes and rockets. you simply have to learn how it works. this is not foolish this is KSP!