[Flightgear-devel] Auto Pilot Reviwed

[Pete M. <AC...@da...>]

I'm a bit confused how and why the auto pilot does certain things.

I think for legacy reasons, its been hacked together and work fine.. 
almost.ish..

There are also duo versions of le interface as defined here.. for end 
users..
http://wiki.flightgear.org/index.php/Autopilot

and interestingly, they appear on the Bravo and 787, my two aircraft of 
interest in creating a motion platform.

However in trying to create simple switches/knobs with Arduino in my 
play cockpit. and motion sim, there are a few issues.

I think that to solve the problem, we need to define the problem more.. 
and imho we are at its most basic looking at the the functionality of an 
aircraft, and the source the developers manual.

At its most basic in what I'd call modern aircraft. the expected 
functionality of an AP would be a set of pots and switches such as
1) Altitude hold - ie maintain a height -> arudio_value = 120 >  
telnet->set('altitude', 0.120);
2) heading hold - ie go that way -> if arudnio_heading_button_on > 
telnet->set('heading', 0);
3) speed setting - ie go at this speed. ->if arduino_button is on then ??

Then we can go nuts with glideslope, climb rate, speed brakes. Some 
aircraft possible cant do this, however most modern aicraft, can and how 
the switches interpolate within the cockpit. At the most I would not 
expect the autopilot to do things generally within a second.. However we 
are looking at at least three sub systems..

How these are delivered from pressing a phycical little button with the 
"heading" end up in a screen automatically heading that way. This would 
be ok, however I cant make the "platform" jerk at he same rate, and 
knock off coffee cups etc.

I'm obviously not close to the code and looking at /HEAD but thus 
require some direction. which leads to the following questions ?

Should the autopilot be a seperate process that just basically inputs 
pilot commands ? ie turn at the same physical rate posibble ?

At the moment I can damp down the movement easily with a couple of 
capacitors.?

Also in the back of my mind is whether we need to create an virtual 
ARINC bus.. ie seperate sub systems ?

Anyway some of my thoughts.. most can be ignored..

Pete ;-)