[simpits-tech] May the Force Feedback be with you...
Akin, Keenan L
simpits-tech@simpits.org
Thu, 6 Feb 2003 08:10:53 -0600
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Ken,
=20
You make excellent points. That is why I send out ideas such as this =
for sanity checks. Sometimes you can be too close to the problem and =
not see something obvious.
=20
Thanks for your input,
=20
Keenan
-----Original Message-----
From: Ken Schlote [mailto:kschlote2@yahoo.com]
Sent: Thursday, February 06, 2003 7:54 AM
To: simpits-tech@simpits.org
Subject: Re: [simpits-tech] May the Force Feedback be with you...
OK, I have a cylinder in front of me and by restricting the air on one =
port makes it harder to move in or out.That is all you need. But the =
need to vent the air to the other side I don't follow. Just restricting =
the air from going in or out of one port will do the same thing. Then =
have the FF solenoid pluse the air into the other side.=20
But if you are going for the most realistic then you need to make the =
cylinder feedback push back on the cylinder (stick) to the trimmed point =
of the aircraft until you retrim the aircraft at which time the forces =
are neutral. The forces want to center the stick to the trim point. Any =
movement will require force in that direction proportional to the air =
speed and by trimming you relieve the force pushing back.=20
Ken=20
Keenan Akin <kakin@yhti.net> wrote:=20
Ken,
The servo operated valve modulates the air venting from one side of the=20
cylinder to the other. When the servo is sensing low airspeeds the=20
valve permits relatively free flow (the stick can be moved with light=20
force). As the airspeed increases, the valves starts restricting the=20
flow proportionally, requiring a higher force to move the stick=20
(representing aero forces on the control surfaces). Remember, I am=20
building a WWII fighter, not a fly-by-wire jet. The solenoid valve is=20
just there to provide pressure "pulses" in response to force feedback=20
signals.
Hope I made sense.
Keenan
Ken Schlote wrote:
> Keenan,
>
> I'm not quite sure why you are using air pressure to increase the=20
> force of a stick. If you are going to use a cylinder then just adjust=20
> the flow entering or leaving the cylind! er! ! . Example: By closing =
the=20
> rear port you either have to pull a vacuum or pressurize the cylinder=20
> which stops you from moving the shaft because the air can not escape=20
> or enter. Adjusting the flow leaving or entering allows the shaft to=20
> move but with more force.
>
> A "V notch port" will do the job. (see attachment). As the V notch=20
> plug is pulled out of the port more air can escape or enter letting=20
> the shaft move with less force. As it moves in, the force increases=20
> because the size of the port decreases. This can all be done with one=20
> servo and cylinder per axis.
>
> Hope this helps. Questions?
>
> Ken
>
> "Akin, Keenan L" wrote:
>
> Okay folks,
>
> Here is my current concept of a pneumatic force feedback actuator
> for my pit. There would be two of these actuators attached to the
> stick (one pitch ! a! ! xis, one roll axis).
>
> <>
> The servo driven valve uses airspeed data to modulate the airflow
> from one side of the cylinder to the other (caused by moving the
> stick). For example, at higher airspeeds, the flow will be
> restricted, causing the stick to be harder to move.
>
> The solenoid valve ports pressurized air to one side of the
> cylinder or to the other only when a force feedback signal directs
> it. Otherwise, it is closed.
>
> Thoughts? Questions?
>
> Keenan
> > ATTACHMENT part 2 image/gif name=3Dffactuator.gif=20
>
>
> =
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<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D581290914-06022003>Ken,</SPAN></FONT></DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D581290914-06022003></SPAN></FONT> </DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN =
class=3D581290914-06022003>You=20
make excellent points. That is why I send out ideas such as this =
for=20
sanity checks. Sometimes you can be too close to the problem and =
not see=20
something obvious.</SPAN></FONT></DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D581290914-06022003></SPAN></FONT> </DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN =
class=3D581290914-06022003>Thanks=20
for your input,</SPAN></FONT></DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D581290914-06022003></SPAN></FONT> </DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D581290914-06022003>Keenan</SPAN></FONT></DIV>
<BLOCKQUOTE>
<DIV align=3Dleft class=3DOutlookMessageHeader dir=3Dltr><FONT =
face=3DTahoma=20
size=3D2>-----Original Message-----<BR><B>From:</B> Ken Schlote=20
[mailto:kschlote2@yahoo.com]<BR><B>Sent:</B> Thursday, February 06, =
2003 7:54=20
AM<BR><B>To:</B> simpits-tech@simpits.org<BR><B>Subject:</B> Re:=20
[simpits-tech] May the Force Feedback be with =
you...<BR><BR></DIV></FONT>
<P>OK, I have a cylinder in front of me and by restricting the air on =
one port=20
makes it harder to move in or out.That is all you need. But the need =
to vent=20
the air to the other side I don't follow. Just restricting the air =
from going=20
in or out of one port will do the same thing. Then have the FF =
solenoid pluse=20
the air into the other side.=20
<P>But if you are going for the most realistic then you need to make =
the=20
cylinder feedback push back on the cylinder (stick) to the trimmed =
point of=20
the aircraft until you retrim the aircraft at which time the forces =
are=20
neutral. The forces want to center the stick to the trim point. Any =
movement=20
will require force in that direction proportional to the air speed and =
by=20
trimming you relieve the force pushing back.=20
<P>Ken=20
<P> <B><I>Keenan Akin <kakin@yhti.net></I></B> wrote:=20
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #1010ff 2px solid; MARGIN-LEFT: 5px; =
PADDING-LEFT: 5px">Ken,<BR><BR>The=20
servo operated valve modulates the air venting from one side of the=20
<BR>cylinder to the other. When the servo is sensing low airspeeds =
the=20
<BR>valve permits relatively free flow (the stick can be moved with =
light=20
<BR>force). As the airspeed increases, the valves starts restricting =
the=20
<BR>flow proportionally, requiring a higher force to move the stick=20
<BR>(representing aero forces on the control surfaces). Remember, I =
am=20
<BR>building a WWII fighter, not a fly-by-wire jet. The solenoid =
valve is=20
<BR>just there to provide pressure "pulses" in response to force =
feedback=20
<BR>signals.<BR><BR>Hope I made sense.<BR><BR>Keenan<BR><BR><BR>Ken =
Schlote=20
wrote:<BR><BR>> Keenan,<BR>><BR>> I'm not quite sure why =
you are=20
using air pressure to increase the <BR>> force of a stick. If you =
are=20
going to use a cylinder then just adjust <BR>> the flow entering =
or=20
leaving the cylind! er! ! . Example: By closing the <BR>> rear =
port you=20
either have to pull a vacuum or pressurize the cylinder <BR>> =
which stops=20
you from moving the shaft because the air can not escape <BR>> or =
enter.=20
Adjusting the flow leaving or entering allows the shaft to <BR>> =
move but=20
with more force.<BR>><BR>> A "V notch port" will do the job. =
(see=20
attachment). As the V notch <BR>> plug is pulled out of the port =
more air=20
can escape or enter letting <BR>> the shaft move with less force. =
As it=20
moves in, the force increases <BR>> because the size of the port=20
decreases. This can all be done with one <BR>> servo and cylinder =
per=20
axis.<BR>><BR>> Hope this helps. Questions?<BR>><BR>>=20
Ken<BR>><BR>> "Akin, Keenan L"=20
<KEENAN.L.AKIN@BOEING.COM>wrote:<BR>><BR>> Okay =
folks,<BR>><BR>>=20
Here is my current concept of a pneumatic force feedback =
actuator<BR>>=20
for my pit. There would be two of these actuators attached to =
the<BR>>=20
stick (one pitch ! a! ! xis, one roll axis).<BR>><BR>>=20
<><BR>> The servo driven valve uses airspeed data to =
modulate the=20
airflow<BR>> from one side of the cylinder to the other (caused =
by moving=20
the<BR>> stick). For example, at higher airspeeds, the flow will=20
be<BR>> restricted, causing the stick to be harder to=20
move.<BR>><BR>> The solenoid valve ports pressurized air to =
one side=20
of the<BR>> cylinder or to the other only when a force feedback =
signal=20
directs<BR>> it. Otherwise, it is closed.<BR>><BR>> =
Thoughts?=20
Questions?<BR>><BR>> Keenan<BR>> > ATTACHMENT part 2 =
image/gif=20
name=3Dffactuator.gif <BR>><BR>><BR>>=20
=
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BR>>=20
Do you Yahoo!?<BR>> Yahoo! Mail Plus <BR>> - <BR>> =
Powerful.=20
Affordable. Sign up now <BR>> <BR>>=20
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0406@netscape.com !=20
05!><BR>><BR><BR></BLOCKQUOTE>
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