expression gains filter and such...

Everything in connection with developing aircraft for FlightGear
bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

expression gains filter and such...

Postby bomber » Mon Sep 26, 2016 5:09 pm

https://forum.flightgear.org/viewtopic.php?f=4&t=30529


Code: Select all

 <filter>
        <name>Door L1</name>
        <type>gain</type>
        <gain>1</gain>
        <update-interval-secs type="double">0.05</update-interval-secs>
        <input>
            <expression>
                <table>
                    <property>/controls/doors/L1-i</property>
                    <entry><ind>0</ind><dep>-80</dep></entry>
                    <entry><ind>1</ind><dep> 80</dep></entry>
                </table>
            </expression>
        </input>
        <output>/controls/doors/L1-o</output>
    </filter>


I've not seen this done before, so can someone point me to any documentation (not holding my breath) or explain this and any more like this I don't know about ?

Maybe we could create a library of these little gems ?

regards

Simon
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

User avatar
IAHM-COL
Posts: 6413
Joined: Sat Sep 12, 2015 3:43 pm
Location: Homey, NV (KXTA) - U.S.A
Contact:

Re: expression gains filter and such...

Postby IAHM-COL » Mon Sep 26, 2016 5:13 pm

https://raw.githubusercontent.com/IAHM-COL/gpg-pubkey/master/pubkey.asc

R.M.S.
If we gave everybody in the World free software today, but we failed to teach them about the four freedoms, five years from now, would they still have it?

Octal450
Posts: 2185
Joined: Sun Oct 18, 2015 2:47 am

Re: expression gains filter and such...

Postby Octal450 » Mon Sep 26, 2016 5:15 pm

I used them in this file in MD-80s, to make custom values.

https://github.com/it0uchpods/MD-88/blob/master/Systems/engine-timing.xml

They are basically gain filters with custom values.

Wiki not very helpful sadly.

I can help :D

bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

Re: expression gains filter and such...

Postby bomber » Mon Sep 26, 2016 5:52 pm

Can I take it these are Flightgear XML 'extensions' for want of a better word and not native JSBsim XML ?
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

Octal450
Posts: 2185
Joined: Sun Oct 18, 2015 2:47 am

Re: expression gains filter and such...

Postby Octal450 » Mon Sep 26, 2016 6:24 pm

It's autopilot/property rule xml

bomber
Posts: 1379
Joined: Mon Nov 30, 2015 3:40 pm

Re: expression gains filter and such...

Postby bomber » Mon Sep 26, 2016 6:50 pm

yes and that property is outside of the JSBsim property tree....

But what we have here are xml functions.. such as the filter

Code: Select all

    <filter>
    </filter>

and others

However these are not anywhere to be found in the JSBsim manual...

And as I do flight models in both flightgear and Outerra I can only use xml functions that are JSBsim if I want an easy transfer from one to the other.

Simon
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

OPFOR77
Posts: 208
Joined: Wed Apr 27, 2016 7:30 pm

Re: expression gains filter and such...

Postby OPFOR77 » Mon Sep 26, 2016 7:39 pm

Yes, these are FG specific, not related to JSBSim.

You can do the same thing as the first bit you posted in JSBSim with a table and clamping the output.
OPRF Fighter Jock and Dev

Octal450
Posts: 2185
Joined: Sun Oct 18, 2015 2:47 am

Re: expression gains filter and such...

Postby Octal450 » Mon Sep 26, 2016 7:39 pm

I don't understand why you are saying JSBsim.

This is a FlightGear XML based expression gain filter...

User avatar
IAHM-COL
Posts: 6413
Joined: Sat Sep 12, 2015 3:43 pm
Location: Homey, NV (KXTA) - U.S.A
Contact:

Re: expression gains filter and such...

Postby IAHM-COL » Mon Sep 26, 2016 7:41 pm

@Josh,
he would just love to be able to use the <filter> options within JSBsim. Which AFAIK, no way.
https://raw.githubusercontent.com/IAHM-COL/gpg-pubkey/master/pubkey.asc

R.M.S.
If we gave everybody in the World free software today, but we failed to teach them about the four freedoms, five years from now, would they still have it?

Octal450
Posts: 2185
Joined: Sun Oct 18, 2015 2:47 am

Re: expression gains filter and such...

Postby Octal450 » Mon Sep 26, 2016 7:56 pm

Yeah.


Return to “Aircraft Development”

Who is online

Users browsing this forum: No registered users and 42 guests