Come back old ASAS - all is forgiven!

[Redstar]

KSP store here too, it feels like the SAS is fighting me all the time going "no red no i want to go this way im sure duna is very nice now but damn it im having fun"

[PwnedDuck]

I honestly can't give any input on plane performance because I have never even touched them. I have only flown Rockets, and am having problems with drift when burning maneuvers, making gravity turns, and when trying to orientate a ship in space (e.g. For maximum solar coverage).

[Neomatt]

Again, that's important: do you have a plugged-in (not using it, just plugged in) controller/joystick?

If you have issues, unplug those, restart the game, and try again, just to be 100% sure that's caused by the game, not a badly-set deadzone.

[ComradeGoat]

From the video, it looks like your CoT might not be lined with your CoM :l If it is, I'm not observing these issues at all honestly.

Of course it is, it's a plane! They don't have vertical symmetry. It's painfully apparent that this slight misalignment is what causes the initial drift. The problem is that ASAS isn't correcting it, when the craft is perfectly capable of correcting that slight imbalance. Indeed, it does eventually do so itself, but only when it's about 13º off the set course.

[Thoughtlessmind]

I'd like to say that I deleted local file through steam and then re-installed and all the weird behaviors went away. I had built @Harvester's test ship and it failed terribly. Did the re-install and it flew straight as an arrow. I'm on windows 7 64bit through Steam. I should also say I started a new save folder as well just encase it had to do with the old data.

[Rastaman]

OK, I made a video. Here is a demonstration of the problem I'm seeing in space. Stock craft, fresh download of KSP, nothing else done in that game other than launch that plane. I also experienced a bit of phantom roll and yaw during the ascent, but did not attempt to correct them. It seems ASAS/SAS will allow a certain amount of drift before noticing something is up and stopping it, but it never returns to where it's supposed to be.

Watch the navball and the pitch indicator in this video. The only keys I pressed throughout are shift and X.

ETA: At one point there seems to be around 13º deflection from the "set course" when under thrust, which it will hold while under thrust, and then return to the set course afterwards. Note is only applying about 30-40% pitch maximum to try and correct, and will apparently deliberately hold the wrong course on a tiny amount of torque, when all it needs to do is apply a bit more to return to where it's supposed to be!

The logical conclusion: You need more powerful gimbal or more wheels.

[ComradeGoat]

Again, that's important: do you have a plugged-in (not using it, just plugged in) controller/joystick?

If you have issues, unplug those, restart the game, and try again, just to be 100% sure that's caused by the game, not a badly-set deadzone.

If you're asking about my video, no. There is no joystick. This is just a MacBook Air with a fresh install of KSP and a stock spaceplane I built which can hold a heading manually, but SAS will hold a heading that's 10-13º off the one it's supposed to hold, because it is very slightly out of balance (which planes will be - it's not really avoidable, but this is why we have gimbals).

[ComradeGoat]

The logical conclusion: You need more powerful gimbal or more wheels.

Watch the video again. The pitch when controlled by SAS never reaches full deflection. It never even comes close. I can correct it myself simply by pressing W. Lack of rotational power is not the issue here.

What's the point in adding more when it won't use what's already there?

[Umlüx]

maybe somebody with a working SAS could post the part files

and then somebody with a broken (steam? ) version could test them/compare them/whatever

[Tiron]

Finally finished uploading. 1080P for your viewing pleasure/downloading displeasure.

Procedure:

1.) Start at -90 degrees pitch.

2.) Apply full right yaw until the -45 degree marker, then release and allow the SAS to take over.

3.) Bring right to +90 degrees pitch

4.) Apply full left yaw until the +45 degree marker, allow SAS to bring to a stop.

5.) Bring left to -90 degrees pitch.

6.) Apply full left yaw until the 0 degree pitch marker, allow SAS to bring it to a stop.

7.) Bring right to +90 degree pitch

8.) Apply full left yaw until the -90 degree marker (yes, 180 degrees), allow SAS to bring it to a stop.

9.) Bring right to +90 degree pitch.

10.) Apply full right Yaw until about the +60 degree marker, allow SAS to bring to a stop.

11.) Push the wrong button while trying to end recording.

What you see here, is that when the SAS is given control, it makes no attempt at all to return the orientation to the point where control was released. Instead, it simply brings the ship, rather slowly, to a halt. The ramping of the control force suggests it's actually getting closer to its aim point as it slows.

The distance past the release point it gets is proportional to the rotational speed when the SAS is given control: The higher the speed, the further off the mark it goes before stopping.

One key thing to note is that each time after it stops, it briefly reverses the controls a tiny amount before settling in. This suggests that it's not merely movement damping, and that there IS in fact a target attitude it's trying to reach. It's just not being set to the release point for some reason. The fact that it's proportional to the movement speed and the way it ramps down as it slows leads me to believe that it's probably resetting the target attitude constantly as it slows, probably being triggered by the SAS's control inputs.

What this means in practical purposes is that whenever you release your controls to the SAS, whatever movement you're engaged in will continue for some distance, and when it's halted the SAS will hold it on a point that's more or less where it stopped at. This means that while making fine adjustments, unless you get the craft all but stopped before you let go, you're going to overshoot by some distance and have to re-correct.

This is on Windows 7 Ultimate 64 bit, KSP version 0.21.0.272 from Steam, on a fresh reinstall with no addons installed. The craft is the final stage of a Kerbal-X with the large (non-torqueing) ASAS added.

System Stats: AMD FX-6300, 8GB DDR3 RAM, installed in ASUS M5A97 running Bios version 1605, with Sapphire Radeon HD 6870, driver version 13.1 (A tad outdated, but the newest ones don't work with an old game I just reinstalled anyway. Or at least, they don't for install purposes. It might work now that it's in. I'm not sure.)

[PwnedDuck]

A good point. People having trouble with the SAS, is your KSP from Steam? Mine's from Steam, and I'm having trouble with SAS.

Storebought KSP, ASAS not working if what It's supposed to do is point the rockets where I told

It to.

[Danger Will Kerbinson!]

The logical conclusion: You need more powerful gimbal or more wheels.

I've built a small, simple, perfectly symmetrical rocket with a dozen reaction wheels and it still wanders. It is noticable in how fast it reacts to turn input so they are doing something, but holding a heading they are not. Not even close. Unlike ComradeGoats plane though mine drifts in random ways instead of always up and down. It handles exactly the way it used to if you had SAS turned off, it needs constant babysitting during a burn.

[Tiron]

I'd just like to point out that if his plane had insufficient control force to hold its heading, it wouldn't shift off target a few degrees and then hold. The fact that it's able to hold a few degrees off indicates that the control forces ARE powerful enough to stop it. If they weren't, it'd keep rotating all the way around, pulling a loop. An accelerating loop, actually, because the 'extra' force the controls couldn't compensate for would lead to a constant acceleration.

It's strong enough, it's just either applying its force too slowly or aiming for the wrong point.

[Alavarien-46]

What you see here, is that when the SAS is given control, it makes no attempt at all to return the orientation to the point where control was released. Instead, it simply brings the ship, rather slowly, to a halt. The ramping of the control force suggests it's actually getting closer to its aim point as it slows.

The distance past the release point it gets is proportional to the rotational speed when the SAS is given control: The higher the speed, the further off the mark it goes before stopping.

I have exactly the same with my storebough KSP and a fresh install without any mods.

[stupid_chris]

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.

Edited July 25, 2013 by stupid_chris

[Conzolax]

Watch the video again. The pitch when controlled by SAS never reaches full deflection. It never even comes close. I can correct it myself simply by pressing W. Lack of rotational power is not the issue here.

What's the point in adding more when it won't use what's already there?

I second this.

Its simply not using the control surfaces/gimballing/Pod torque, its just trying to give you a smooth ride just like the Avionics package does, and does not really care about which direction its going.

[ComradeGoat]

I'd just like to point out that if his plane had insufficient control force to hold its heading, it wouldn't shift off target a few degrees and then hold. The fact that it's able to hold a few degrees off indicates that the control forces ARE powerful enough to stop it. If they weren't, it'd keep rotating all the way around, pulling a loop. An accelerating loop, actually, because the 'extra' force the controls couldn't compensate for would lead to a constant acceleration.

It's strong enough, it's just either applying its force too slowly or aiming for the wrong point.

Her plane, actually, but thankyou for getting this. It's so frustrating to keep getting told I need to add more rotation force when it won't use the force it has. :-(

[ComradeGoat]

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.

Watch the video I posted. It starts out in a stationary, held position, wanders from it when I apply thrust, and then holds a different one 10-13º away. When I stop thrust it returns to the original position. Reapply thrust and it wanders again.

I'm not asking to press T while spinning wildly and come to the point where I pressed it, but it would be nice if I can point in a direction, apply thrust, and actually have the vehicle go in that direction.

[Tiron]

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.

Except there's no PRECISION to it at all. The fact that it lets it keep sliding on after you've let go is a PROBLEM. it is a FAULT. it prevents you from being able to point exactly where you want to point, because you have to somehow manually get on that point and then stop there, which is extremely difficult at best. Sure, it holds once you've gotten stopped, but it doesn't MATTER because it's absurdly difficult to get it to the attitude you WANT it to hold.

The problem with the old SAS wasn't that it brought you back its target attitude: It was that it wouldn't ever change what its target attitude was unless you turned it off, then back on. If you tried to use your controls, instead of adjusting the target attitude to where you moved the craft to, it would keep the old target and actually fight you to try to get back to it.

The new version allows controls to override it, so that isn't a problem anymore. What it SHOULD be doing, is setting the target attitude to the point where you release the controls. Not moving back to where you started, to where you let go.

Mechjeb's killrot function has worked exactly this way as long as I've been using it, and it's why I haven't used stock SAS since I started using Mechjeb. When I first bought the game. in 0.16.

If you want to see the behavior I'm talking about as what it SHOULD have, try the 'KillRot' function on Mechjeb's SmartASS. It's basically identical to the old ASAS, only it allows for control input overrides and takes the point where you release as the new target attitude automatically, without having to turn it off. But it's just as inefficient and wobbly as the old SAS too. I'd really like to use the new SAS at least some of the time, but as it stands it's unusable and vastly inferior to Mechjeb's very flawed KillRot implimentation.

[stupid_chris]

Watch the video I posted. It starts out in a stationary, held position, wanders from it when I apply thrust, and then holds a different one 10-13º away. When I stop thrust it returns to the original position. Reapply thrust and it wanders again.

I'm not asking to press T while spinning wildly and come to the point where I pressed it, but it would be nice if I can point in a direction, apply thrust, and actually have the vehicle go in that direction.

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.

[ComradeGoat]

Sure, it holds once you've gotten stopped, but it doesn't MATTER because it's absurdly difficult to get it to the attitude you WANT it to hold.

It doesn't even do that. Watch the video I posted a couple of pages back.

[Sardonyx]

I was hoping to get some clarification on whether ASAS/SAS is able to manipulate control surfaces like it used to? I have tried every available one including the SAS/ASAS from the previous version and the control surfaces are not turning.

Yes, SAS will move control surfaces. Take a look at my videos in this thread and you can see them under SAS control:

http://forum.kerbalspaceprogram.com/showthread.php/41978-0-21-SAS-Test

[Temeter]

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.

Ah, i see now what you are talking about^^

You're right, this is how sas should behave, and it would be the more better solution - if it worked. But in ksp construction, physic and even tiny asymmetry tend to push your rocket and spaceships of course, especially when you engage time acceleration. Atm such a system can't hold the course, and that's the problem, as well as the reason for the old asas just locking to a specific attitude.

I also had the issue of the sas not (or insufficiently) using the rocket gimbals or control surfaces, causing the attitude of my plane to "wander" slowly in a direction, or making a rocket spin and steer of course, when the crafts should be able to fly perfectly stable.

[stupid_chris]

Tiron, I know all of this. I also use MechJeb more often than I pilot myself. All I mean, is that, it's meant to let you drift and slowly come to a stop. It's literally programmed not to come back or anything, it simply wants to come to a stop, smoothly, then hold the vector. Go read the link I posted, you'll understand. I think we all should wait for Chad to make a blog post too.

EDIT:

Ah, i see now what you are talking about^^

You're right, this is how sas should behave, and it would be the more better solution - if it worked. But in ksp construction, physic and even tiny asymmetry tend to push your rocket and spaceships of course, especially when you engage time acceleration. Atm such a system can't hold the course, and that's the problem, as well as the reason for the old asas just locking to a specific attitude.

I also had the issue of the sas not (or insufficiently) using the rocket gimbals or control surfaces, causing the attitude of my plane to "wander" slowly in a direction, or making a rocket spin and steer of course, when the crafts should be able to fly perfectly stable.

Yes and it does take account for this. Once it is locked in position, it will hold this position, I launched to the Mun and to Duna earlier, I had a big launcher on the pad, I didn't disable any gimbal, activated SAS, throttle up, and I literally had to touch nothing but throttle and stage all the way to 10km. It does hold the heading.

Edited July 25, 2013 by stupid_chris

[Danger Will Kerbinson!]

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.

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.