autothrottle

[imported_airdemon]

i am trying to have the servo controler work in my sim for autothrottles i have gotten the servos to move the levers in my sim but i want the servos to only work when the autothrottle is ingaged as this is causing problems when i manualy fly
i am also using PM so this needs to work (not move the throttles)anytime the A/T is just armed not engaged in any mode
ani IDEAS???

[alandyer]

If the throttles move in Microsoft Flight Simulator the servos will track throttle position.

When A/T is armed but not engaged do throttles move is MS-FS?

[imported_airdemon]

yes the throttles in microsoft move when i manualy move my throttles and the servos react to this

[alandyer]

When you say "manually fly" - is this with actual throttle levers or on-screen?

Still trying to understand what problem is.

[737FlightSim]

Hi Alan
I think he is saying that if he Manually changes the Thrust lever position the servos want to move the levers back to the position, before he manually moved the thrust levers. The servos want to hold the commanded position, and he wants to move them to a new position, and have them held there.

David

[alandyer]

Getting into tug-of-war with servos. Right?

This is a force-feedback problem, where you have a sensor and servo sharing a common moving component.
Competing "sense" and "command" signals.

David, correct me if I'm wrong.
Aircraft manufacturers spend quite a bit of money resolving this by having a force sensor on the throttle lever that detects manual input and inhibits commands from automated system(s).
(If throttle command/sense split exceeds certain parameters the auto-throttle disconnects). Throttles have a clutch built into the throttle lever mechanics. (Rob has a servo arrangement where he is able to overcome servo torque).

Offsets in 3330 - 3336 range is intended for joystick inputs. The "Sense" signal.
Offset 310A provides an inhibit to the "Sense" signal. It is not a "Command" inhibit signal. Would have to speak with PM folks to find out if and how their software operates with that offset.

Ultimately a software solution can only switch throttle servos off when PM autothrottle is driving throttles.

This will not be a solution for those builders that want to manually override throttles when autothrottle is driving throttles. Part of that solution will need to be solved mechanically.

Matt, does Phidgets still have force sensors in stock?

Regards,
Alan.

[imported_airdemon]

i solved the problem
i turn toff the servos when this is set
from the FSUIPC
SDK.

Controls the joystick connection to the main flight controls. Normally all
zero, set the following bits to actually disconnect the specific joystick
axes (from least significant bit = 0):
0 Elevator

1 Aileron

2 Rudder

3 Throttles (all)

4 See below

5 Elevator trim

This feature is intended for use in protecting autopilot flight from
interference from axis flutter. In order to protect the user from a broken
or crashed application, all the flags are cleared 10 seconds after they have
been set, so applications will need to repeat the setting every few seconds.

If the user option is set to automatically disconnect the trim axis in FS
A/P vertical modes, the disconnection of Elevator inputs via bit 0 above
also disconnects Trim even if bit 5 is not also set. This allows existing
A/P or fly-by-wire applications to work with those user implementations
using a trim axis.

Additionally, bit 2^4 is available to switch "throttle sync" on. In this
mode all throttles are driven from the main throttle or throttle 1 inputs,
and other throttle inputs are discarded. (The same option can also be used
from an optional Hot Key).

See also offsets 3328-3339, which provide the live axis values, post
calibration. These would have been applied to FS if not prevented by the
flags above. Applications can use these facilities to provide a responsive
"fly-by-wire" control.

[alandyer]

I was curious as to how you turn off servos.

What offsets are you using for Throttle position sensing?

[imported_airdemon]

088C Engine 1 Throttle lever, –4096 to +16384 and 0924 Engine 2 Throttle lever, –4096 to +16384

to move the throttles when the A/T is on and PM will set 310A 3 Throttles (all)
which will trip a relay to apply power to the servos
when this is not set (or set back to 0) it will turn the relay off so i can manualy move the throttles

[alandyer]

That is so cool!