New SAS functionality and You! [0.23 Update]

[Mygnol]

Vanamonde is not alone. I didn't even mess around trying to save anything, just wiped all local files from Steam, ditched the entire KSP folder inside of steamapps and let it all come in fresh.

I have had rockets veer off course right at launch and then continue that new unplanned heading very well like it was just a momentary lapse. Sometimes they fly perfectly and respond to inputs I give, other times they decide to put some other directions into mix for fun. For example during a gravity turn it should just be a matter of a few pushes of D to make the turn right on the 90 degree line and all other axes are to remain locked, but they are not...sometimes it drifts up and down at random, with the simplest of ships.

Other problems include the inability to hold to a maneuver node marker during a warp. I don't mean how sometime you would hit warp and the blue mark would jump a half inch or so, but it will drift during the warp when things are not even supposed to be subject to physics, its just a nice slow drift while at 50x warp.

When I set the ship to face Normal to watch where it would drift and how fast it won't do it. Stays on that mark for rotation after rotation like it should with that heading. But try to get it to hold any other heading and it just drifts and sways, thrust, no thrust...doesn't matter.

Clearly the program is not behaving the same for everyone.

Seconded, I have that same problem with my rockets. Wiped the KSP folder clean, launched a rocket, and it decided to fly perfectly fine, until I poked a button to adjust it's heading. The entire thing decided that my prograde marker was going to eat it, turned 90 degrees, and held there. And when I tried to straighten it back up, it sent itself into a slow, painful roll, before deciding to give up on life and cartwheeling to it's death by rotating one axis while keeping the others locked.

[Danger Will Kerbinson!]

Did you guys try to delete your settings file and reboot the game? Harv proposed that earlier today, just wondering if that worked or not.

Is there another settings file that would not have been deleted from wiping the entire KSP file under Steam Apps?

[StainX]

Vanamonde runs Windows and he has issues. Windows here to and everything works.

EDIT: Guys, random question, but how many of you who have problems are using a joystick?

Joystick attached.... but not used it in new version yet, no sas problems so far!

Also, i had some joystick/gamepad issues with older game versions, where the joystick was not calibrated so the craft always pulled in one direction slightly.

[Neomatt]

Joystick attached.... but not used it in new version yet, no sas problems so far!

Also, i had some joystick/gamepad issues with older game versions, where the joystick was not calibrated so the craft always pulled in one direction slightly.

Actually, that's a good point: do people with ASAS/SAS issues have a controller/joystick plugged in? (even if it's left on the desk)

Since the new SAS does not filter input noise, maybe try to increase the deadzone on the 2 control axis.

[stupid_chris]

Is there another settings file that would not have been deleted from wiping the entire KSP file under Steam Apps?

It may be corrupted anyway, keep the same install and delete it.

[Monkeh]

Can confirm Mr. _chris's statements and observations above. No problem whatsoever for this kerbonaut. I have no xbox controller or joystick plugged in when I play.

Edited July 25, 2013 by Monkeh

[njd80]

In the early media exclusive video http://youtu.be/-tslKIlAxHQ - C7 mentions joysticks and the need to set deadzones. I can imagine that having a joystick or controller plugged in might cause the kind of problems people are seeing with the SAS.

[Louhikarme]

I just made Vanamondes rocket and tested it out. no problems. sas enabled, throttled up, launch and it flew straight, then when i changed heading manually it kept the heading where i left the key, allthough minor thing is that when i left the key at 45 degree it climbed up 5. so needed to do couple adjustment key presses to to get it that 45 degree mark. but once it was there, it stuck and rocket flew no problem.

side note, i just updated my steam copy (running on win7 64bit), took old save and ran it on there even. Also no controller attached. guess i'm lucky no problems with sas so far.

[M33pn8r]

Just wanted to pop by and say that I was also having some wobbly heading issues with the new update. However, once I unplugged the 360 controller I had in my pc, it seems to have smoothed it out.

[KerbMav]

Win 64bit, no controllers, updated steam version from .20

(will try clean download and add my version number in about 3-4h)

Rocket yesterday flew quite normal - but had to correct my heading after gravity turn until it stuck where I wanted it to be - only had four winglets, one gimbaling Skipper (later Poodle) and the built in torque of the big probe core - in orbit glided a bit after fast turns, had to realign it with my desired heading, but it kept steady.

Tried to orbit the Spirit Stock spaceplane (from that nice fellow whos name I cant remember right now) - was the first plane I got totally smoothly into orbit on first try! Yesterday the nose kept dropping a few degrees after maneuvering, had to aim higher for it to settle on the angle I wanted it to - slight roll at higher AOA too. At 20+km it got sluggish, nose dropped, movement on all axis more or less, spun out of control after all. Switching to rocket engines didnt help. Caught the "descent" and made a steady gliding landing over water (broke apart on splash down sadly, but crew survived).

So, I am not quite sure if I have problems or not, because the Spirit is a pre.21 design and I added 5 parts too.

[DMagic]

Okay, but how do we dock if our ship is spinning (SAS wont stop it)? How do we fly a plane long distances (SAS wont use control surfaces)? Finally, how in Kerbin do we do a long burn with a ever so slightly asymmetrical craft (SAS doesn't care)?

Are you referring to out of control spinning with no input? If you have some kind of phantom rotation then it's a bug, and if you can reproduce with just stock parts you should definitely fill out a bug report. This has been around for a while and it is definitely a problem; it might be caused by parts clipping through each other or it might be something else, so bug reports and craft files are essential for fixing this. And this might not be related to the new SAS functionality. The old ASAS may have been able to compensate for this, but in some cases the new SAS might not be able to, that doesn't necessarily mean that there is anything wrong the new SAS, just that it works differently from the old ASAS.

I don't know about space planes. Maybe the solution is to make the avionics package more aggressive and update the description to make this difference clear.

Asymmetrical crafts are inherently unstable. Maybe the old ASAS was able to compensate in some cases, but that doesn't mean that you should expect a craft that was stable in 0.20 to always be stable in 0.21. You might be able to keep it stable with many more inline reaction wheels, more RCS, or more command pods, or you might not be able to. If you are going to fly something inherently unstable then you should probably be prepared to babysit it during long burns.

Can you explain how the new SAS does its math? "It holds a heading" "It's not an autopilot" how do you reconcile that contradiction? If it holds an attitude it's an attitude autopilot.

What PID values does it use? How does it derive them? When are new attitude target values captured? What control surfaces does it use and when?

You'll have to wait for C7's blog post for more details about how the new SAS system actually works.

And I changed the wording to make it clear that it can only try to maintain a heading (this is after all what the old ASAS did, just more aggressively), but it may not be aggressive enough.

This. Without using MechJeb to keep a certain angle, how are we supposed to do this? Are we now expected to micro-manage things

It seems that way. Better design and more effective use of control mechanisms may allow you to maintain a heading, or it might not.

And I can almost guarantee you that, within a week or two, someone will make a standalone ASAS functionality plugin. But really I see no reason why someone can't just use MechJeb to maintain a heading and just ignore all of the other features of the plugin (assuming that it works the same way when updated).

I am baffled. I tried a small rocket and launched one test with each of the guidance pieces, and NONE of them could hold a heading even just coming straight up off of the pad. I tried combining the ASAS with the others, and still nothing. Surely there must be some way to make a ship simply fly straight without constant admonishments from the player?

There is definitely something wrong here. I have tried building something very similar to your rocket and SAS does a fairly good job of maintaining heading; not perfect, but it never veers way off course like your example.

And like I said in the first post, I don't think there is any reason to use two parts with SAS functionality. If someone can explain why multiple SAS controls can help than I would like to hear it and understand why. But until then I think you should only use SAS parts (Avionics Package, Inline Advanced Stabilizer, or the 2.5m ASAS module) when building probe crafts, or maybe planes. If you want more torque you can put multiple Inline Reaction Wheels, but don't use multiple SAS parts.

If people are still having issues like this after starting from a clean install, with no mods, new crafts, and no joystick/gamepad, then there is a bug and you should report it properly, not just in random SAS threads.

[Captain Sierra]

Okay, I knew it was turned down. I was fully prepared for a less aggressive SAS but after finally getting my hands on it, wow. Squad, fix this! I had a rocket with winglets, reaction wheels for torque, power, and inline reaction system for both torque and SAS control. It was incapable of holding this little rocket to a heading. The air kept forcing it to prograde and nothing else. And my Ferram Aerospace is still broken, I shouldn't be getting that!

Rocket in question:

So, either tell me what I'm doing wrong, or kiss me goodbye as a tester. I am sticking with .20.2 on all my KSP installs other than stock backup. I want my SAS to bite, especially for the big payloads like station cores and the entire Lazarus project.

[stupid_chris]

That's confusing too. I'm nearly sure that if I recreate that rocket, it will fly true like an arrow. Do you have a joystick/controller connected to your computer and did you try deleting your settings.cfg?

[Captain Sierra]

I did a hard install, my settings.cfg was overwritten. It is slightly asymmetrical because of the sepatrons but if that was the problem, it would lean back towards me, instead it tries to drift into a westward gravity burn off the pad. SAS will stop it but it won't get me back to vertical. My joystick is not configured on my stock backup of KSP. I only use it on my expert version (which has Ferram, the only way I can fly) which is my least played. This was done on my newly updated stock backup KSP install.

[stupid_chris]

My joystick is not configured on my stock backup of KSP.

Disconnect it. I don't know why, but even if they aren't configured to work, joysticks tend to screw everything up. And delete the settings file anyway, apparently the one with the download isn't "default" and deleting it causes a default one to appear which works better :l

[Captain Sierra]

The joystick wasn't (and still isn't) plugged in. I deleted my old stock backup of KSP and redownloaded from the website. There is no way the settings isn't default.

[astropapi1]

I'm running on Windows 32b.

My problem is that, even having engine gimbal, winglets/canards, reaction wheel thingies, etc. something as little as an off-center Small RCS tank will make it turn.

I mean, WTF? It's like the SAS uses 0.00001% of what's available.

EDIT: I have never used a joystick in KSP, and I'm running on a completely fresh install from the KSP Store.

Edited July 25, 2013 by astropapi1

[Captain Sierra]

Thats exactly what it does. Look at my image last page. I can make that rocket to backflips at nauseating speeds with the torque and winglets but it can't even hold me vertical.

It's using about 8% of what it has to use. Damnit Squad, make these things bite! WE NEED FORCE!

[stupid_chris]

I am beyond confused. It's literally working perfectly here. I don't understand how it can vary from a game to another this much. I'm tempted to do a video to show how straight it is here.

I literally stayed up all night trying to figure this out. Every time I think I might've found a way to track this down it slips away. Man this is worse than cancer.

[Captain Sierra]

let me go back in and send you the craft file. try it with the actual ship in question.

EDIT: Craft file: https://docs.google.com/file/d/0B_BVD9gAcd6BTS1laDhPN0llLW8/

Edited July 25, 2013 by Captain Sierra
added craft file

[stupid_chris]

Alright, thanks. Testing it out now.

[Captain Sierra]

Let me know if it does the slight westward gravity burn on you.

EDIT: I REALLY don't get this. Stock planes fly amazingly but my dismal rocket can't fly right. Every time I go into the gravity burn it won't hold course. The air will force it off to prograde. And I don't even have FAR in yet!

Edited July 25, 2013 by Captain Sierra

[stupid_chris]

Alright, so after testing this for a few seconds, I came to a few realisations

1) launch clamps. This was way too wobbly on the pad alone, there's like no way to launch straight.

2) After adding those and going up for a while, I realized the winglets rapidly lost any kind of control. After going up for a while, I started to slowly drift west indeed.

3) I switched for a LV-T45 and then the problem became the separatrons. CoM slightly misaligned with the CoT and the rocket just ended up tilting towards me.

4) added those symmetrically and then everything was perfect. It launched straight up. At 10k, the small westward curve was still there though.

Although, this westward curve is actually the planet's rotation. As it goes under you and you go straight up, it gives the surface velocity a was spin. So really, if you have enough control and you align your things properly, it should go like a dart. At least it did for me.

[Captain Sierra]

Alright, so after testing this for a few seconds, I came to a few realisations

1) launch clamps. This was way too wobbly on the pad alone, there's like no way to launch straight.

2) After adding those and going up for a while, I realized the winglets rapidly lost any kind of control. After going up for a while, I started to slowly drift west indeed.

3) I switched for a LV-T45 and then the problem became the separatrons. CoM slightly misaligned with the CoT and the rocket just ended up tilting towards me.

4) added those symmetrically and then everything was perfect. It launched straight up. At 10k, the small westward curve was still there though.

Although, this westward curve is actually the planet's rotation. As it goes under you and you go straight up, it gives the surface velocity a was spin. So really, if you have enough control and you align your things properly, it should go like a dart. At least it did for me.

1) N/A. It's steady as a rock on the pad without them for me.

2) I have the command pod, inline reaction system, and extra reaction wheels on it. I shouldn't need gimbaling with that level of torque!

3) How come that wasn't a problem earlier then?

ALTHOUGH) Duely noted. But then why won't the SAS hold it straight vertical? I'm okay with westward drift as long as it doesn't change my orientation but the new SAS seems so weak that even aerodynamic effects are pushing it around. What the hell? I don't even have Ferram Aerospace in yet! God help me when I do.

[stupid_chris]

Torque in atmosphere is suprisingly weak. Really, you shouldn't rely on torque in the atmosphere at all, it has little to no power compared to gimbals and winglets while going through air. Would you give a RL rocket a few reaction wheels and no other means of control and expect it to fly straight?

For the separatrons, it was an issue earlier, but it wasn't the most pressing issue, that's why I didn't mention it.

And lastly, it does hold it vertical. So vertical that Kerbin has the time to rotate under it. It doesn't hold it vertical compared to the surface, it holds it vertical compared to a preset space. The atmosphere isn't pushing it around, it's really just the planet moving and the navball moving around with it. If you looked at it from a fixed point of view, you'd see the rocket going perfectly straight up.