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Erickson S-64 Aircrane anyone?

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Re: Erickson S-64 Aircrance anyone?

Postby tat » Thu Jun 11, 2009 10:26 am

Hi there,

I'm glad to hear it is stored in a common folder.
I've been updating OH-1/Nasal/fcs.nas for adding more functions.
I'll update the common fcs.nas tonight.

p.s.
Now it has a backup FCS that provides a rate dumper mode by default.
You can try OH-1 on CVS and see how it works.
Pressing "BU-SCAS" button on thr cockpit panel in the air changes FCS mode from SCAS to backup mode which provides only SAS.

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Re: Erickson S-64 Aircrance anyone?

Postby tat » Thu Jun 11, 2009 1:06 pm

tat wrote:I've been updating OH-1/Nasal/fcs.nas for adding more functions.
I'll update the common fcs.nas tonight.


Done.
Now you can use Backup SCAS. see OH-1/Nasal/fcs-config.nas and OH-1/Instruments/afcs.xml for detail.
OH-1 atm uses SAS for backup FCS (this is just for simulating a real redundant FCS system, and thus it reuses the primary SAS for backup FCS).

Btw, it is safer to reset the fcs parmeters on reinit.
see the end of OH-1/Nasal/fcs-config.nas for the code.

One more thing. I added a useful function so you can dump the current parameters for development use.
try dumpParameters() from Nasal console. it will dump the hash tree under /controls/flight/fcs/gain.
For OH-1, you can type:
OH1.dampParameters();

tat
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Re: Erickson S-64 Aircrance anyone?

Postby FlugHund » Sun Jun 14, 2009 11:04 pm

Hi Chopperbuilders,

now that everything seems work with the Crane I updated its folder and made some testflights. And I have to say you made a real good job! With SAS, CAS and Autohover enabled the Crane really hold its position and heading very well - even if the movements are a bit hectic, hehe.

However, I still have not figured out what SAS actually does. I prefer to have it enabled during flight while I disbable CAS. On ground I enable CAS to prevent the Crane from rotating.

Can one of you please tell me and the other readers here what the abbreviations (SAS and CAS) stand for? I searched the web a few times during the past weeks but was not successful at finding info about them.

Thanks in advance and also thanks for this great model :!:

Greetings
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Re: Erickson S-64 Aircrance anyone?

Postby helijah » Mon Jun 15, 2009 8:38 am

hi

S.A.S. : Stability Augmentation System

C.A.S. : Control Augmentation System

That I do not know more;) This is what I understood from a discussion on IRC.

Ah, it seems that the two are inseparable, therefore TAT should combine the two into one function.

Otherwise the side is looking rather F.C.S. functionalities or I.F.C.S. (Flight Control System or Intelligent Flight Control System)

Best regards. Emmanuel
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Re: Erickson S-64 Aircrance anyone?

Postby HHS » Mon Jun 15, 2009 5:14 pm

FlugHund,

SAS- that dampes the rate of the movements of the heli. Means- the heli gets more sluggish, which makes it a bot more stable.
On all middle and big helis is this a standard feature!
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Re: Erickson S-64 Aircrance anyone?

Postby tat » Tue Jun 16, 2009 3:15 am

HHS wrote:FlugHund,

SAS- that dampes the rate of the movements of the heli. Means- the heli gets more sluggish, which makes it a bot more stable.
On all middle and big helis is this a standard feature!


You can see how SAS works by engaging/disengaging SAS while applying "full roll." you'll see engaging SAS restricts the roll rate.

CAS adjusts the pilot's input so heli's maneuver goes close to pilot's expectation. There're lots of factors that affects roll/pitch/yaw rates so a certain stick movement will output different rates depending on a situation. CAS is for eliminating such factors and gives a constant maneuver for the same input. There are some ways to implement CAS, including attitude control, rate control, and air speed control. OH-1 has attitude control and rate control, and you can switch these.

You can see how CAS (attitude command) works by keeping the stick to the same position, and heli (say OH-1) will keep its bank/pitch angle as long as possible.

Some helis have combined CAS and SAS (called SCAS), and others have separated SAS and CAS. OH-1 has SCAS for primary FCS, and SAS for backup FCS.

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Re: Erickson S-64 Aircrance anyone?

Postby jiraya66 » Mon Aug 31, 2009 11:52 pm

I can't take off this chopper, everytime before it takes off it goes up right and roll on the side.
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Re: Erickson S-64 Aircrance anyone?

Postby HHS » Tue Sep 01, 2009 5:23 am

jiraya66 wrote:I can't take off this chopper, everytime before it takes off it goes up right and roll on the side.


First: check your trim settings ( you can use the HUD)

Then: it sounds more like not enough practice. I had the same issues when I started to learn to fly helis in FG. The aircrane is a very realistic one, based on datas by the nasa, so try again with putting the stick against the side it wants to roll. Look what happens and contraact. It needs some time to fly the aircrane and maybe the aircrane isn't the best to learn. Maybe this helps: http://wiki.flightgear.org/index.php/Flying_the_Helicopter
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Re: Erickson S-64 Aircrance anyone?

Postby Bravo » Thu Oct 29, 2009 12:54 am

how do you trim a helicopter or plane's ailerons?
If you need anything just PM me.
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Re: Erickson S-64 Aircrance anyone?

Postby mdsmith » Thu Oct 29, 2009 10:31 am

Bravo123 wrote:how do you trim a helicopter or plane's ailerons?

http://ezinearticles.com/?Helicopter-Cy ... id=2393743
This is for helicopter trimming (which I'm not familiar with nor do I know if its implanted in FG or not) in general. (Note: a normal helicopter doesn't have ailerons, it uses blade pitch movements;))

AFAIK There is no keys for aileron trim in FlightGear (But I may be wrong of course) but there are airplanes that have aileron trim (The Seneca II and P-51D are two of them iirc).
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Re: Erickson S-64 Aircrance anyone?

Postby HHS » Thu Oct 29, 2009 10:43 am

mdsmith wrote:
Bravo123 wrote:how do you trim a helicopter or plane's ailerons?

http://ezinearticles.com/?Helicopter-Cy ... id=2393743
This is for helicopter trimming (which I'm not familiar with nor do I know if its implanted in FG or not) in general. (Note: a normal helicopter doesn't have ailerons, it uses blade pitch movements;))


It is implemented-> data/Nasal/aircrafts.nas ->autotrim

And how to trim a aircraft is a basic knowledge to fly a aircraft- just look into the Manual, Aircrafts Help etc...
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Re: Erickson S-64 Aircrance anyone?

Postby jiraya66 » Sat Nov 07, 2009 5:29 pm

HHS wrote:
jiraya66 wrote:I can't take off this chopper, everytime before it takes off it goes up right and roll on the side.


First: check your trim settings ( you can use the HUD)

Then: it sounds more like not enough practice. I had the same issues when I started to learn to fly helis in FG. The aircrane is a very realistic one, based on datas by the nasa, so try again with putting the stick against the side it wants to roll. Look what happens and contraact. It needs some time to fly the aircrane and maybe the aircrane isn't the best to learn. Maybe this helps: http://wiki.flightgear.org/index.php/Flying_the_Helicopter


Nothing work and i can't enable SAS, CAS, and auto-hover the keys don't work with this chopper.
But on the OH-1 it works great.
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Re: Erickson S-64 Aircrance anyone?

Postby FlugHund » Sat Nov 07, 2009 8:13 pm

jiraya66 wrote:Nothing work and i can't enable SAS, CAS, and auto-hover the keys don't work with this chopper.
But on the OH-1 it works great.

Try again with this version: http://helijah.free.fr/flightgear/tar.g ... 009.tar.gz
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Re: Erickson S-64 Aircrance anyone?

Postby HHS » Sat Nov 07, 2009 9:03 pm

jiraya66 wrote:
Nothing work and i can't enable SAS, CAS, and auto-hover the keys don't work with this chopper.
But on the OH-1 it works great.

As I am already here: It could be that you use the wrong keys- this are maybe a bit different to the OH-1. They are ment in Aircraft help (F10-key-Help-....)
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Re: Erickson S-64 Aircrance anyone?

Postby jiraya66 » Sat Nov 07, 2009 10:27 pm

No it's not i checked the help menu of the aircrance,
and the xml files too i use the good key.
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