[SOLVED] 777 trim broken

Everything in connection with developing aircraft for FlightGear
Octal450
Posts: 2185
Joined: Sun Oct 18, 2015 2:47 am

Re: 777 trim broken

Postby Octal450 » Wed Jun 01, 2016 3:40 pm

Great guys, I'll give it a nice test.

KL-666
Posts: 1610
Joined: Mon Sep 28, 2015 8:42 am

Re: 777 trim broken

Postby KL-666 » Thu Jun 02, 2016 11:49 am

Ok, i experimented a bit with the requirements i put down in my previous post, resulting in the following code which meets the requirements now. Not sure if it is done in the right place though.

777-autopilot.xml (Stabilizer Control)

Code: Select all

        <config>
            <Kp>+0.0</Kp>
            <Ki>
                <condition>
                    <property>instrumentation/afds/inputs/AP</property>
                </condition>
                <value>-0.5</value>
            </Ki>
            <Ki>
                <condition>
                    <and>
                        <not><property>instrumentation/afds/inputs/AP</property></not>
                        <greater-than>
                            <property>position/gear-agl-ft</property>
                            <value>50.0</value>
                        </greater-than>
                        <greater-than>
                            <property>orientation/roll-deg</property>
                            <value>-5.0</value>
                        </greater-than>
                        <less-than>
                            <property>orientation/roll-deg</property>
                            <value>5.0</value>
                        </less-than>
                    </and>
                </condition>
                <value>-0.02</value>
            </Ki>
            <u_min>-11.0</u_min>
            <u_max>4.0</u_max>
        </config>


I modified the second condition and changed <Kp>+0.0</Kp>. I do not know if the + is necessary, i did it to indicate delta.

Now a long flare is not messed up by auto trim, and if i roll out of a long turn, i am not mistrimmed insanely up anymore.

Maybe someone wants to consider to build such logic in the 777?

Kind regards, Vincent

Hyde
Posts: 16
Joined: Sat May 28, 2016 12:30 pm

Re: 777 trim broken

Postby Hyde » Thu Jun 02, 2016 12:21 pm

Thank you, Vincent.
I'm on job (real life) now. I will fix after finish.

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

Re: 777 trim broken

Postby Octal450 » Thu Jun 02, 2016 4:37 pm

@KL-666
@Hyde
Tested, this improves!

Hyde
Posts: 16
Joined: Sat May 28, 2016 12:30 pm

Re: 777 trim broken

Postby Hyde » Thu Jun 02, 2016 7:56 pm

I've pushed the change.
Thanks.

KL-666
Posts: 1610
Joined: Mon Sep 28, 2015 8:42 am

Re: 777 trim broken

Postby KL-666 » Thu Jun 02, 2016 11:26 pm

Hello Hyde,

Tested tonight, and the auto trim seems to be free of adverse side effects now. Will have to fly a bit more, but for now the plane flies very natural overall with the auto trim. Nice job.

Kind regards, Vincent

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

Re: 777 trim broken

Postby Octal450 » Thu Jun 02, 2016 11:36 pm

Hyde, may I adapt this for the MD-11?

KL-666
Posts: 1610
Joined: Mon Sep 28, 2015 8:42 am

Re: 777 trim broken

Postby KL-666 » Fri Jun 03, 2016 12:07 am

Hello Hyde,

I saw on the other forum talk about 250 kts below fl 100. It is fine if the autopilot preselects 250 kts at a certain alt during descent. But beware to not enforce it. A pilot must be able to select a higher speed below fl 100 when atc requests it.

Kind regards, Vincent

Hyde
Posts: 16
Joined: Sat May 28, 2016 12:30 pm

Re: 777 trim broken

Postby Hyde » Fri Jun 03, 2016 1:07 pm

it0uchpods wrote:Hyde, may I adapt this for the MD-11?

Of cause you can. ;)

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

Re: 777 trim broken

Postby Octal450 » Fri Jun 03, 2016 4:19 pm

@Hyde
wonderful thanks!


Return to “Aircraft Development”

Who is online

Users browsing this forum: No registered users and 8 guests