[simpits-tech] May the Force Feedback be with you...

Akin, Keenan L simpits-tech@simpits.org
Fri, 7 Feb 2003 07:45:05 -0600


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Ken,
=20
Actually you did save me some work and helped me to rethink quite a few =
things.  I will come back with a revised version for you guys to comment =
on.
=20
Keenan

-----Original Message-----
From: Ken Schlote [mailto:kschlote2@yahoo.com]
Sent: Thursday, February 06, 2003 4:36 PM
To: simpits-tech@simpits.org
Subject: RE: [simpits-tech] May the Force Feedback be with you...



Keenan,=20


I hope I saved you some work or maybe I made it more complicated.=20


Good luck,=20


Ken=20


 "Akin, Keenan L" <keenan.l.akin@boeing.com> wrote:=20


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 ! pi! ! tch ! 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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> Yahoo! Mail Plus=20
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> Powerful. Affordable. Sign up now=20
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<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D645144313-07022003>Ken,</SPAN></FONT></DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D645144313-07022003></SPAN></FONT>&nbsp;</DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D645144313-07022003>Actually you did save me some work and helped =
me to=20
rethink quite a few things.&nbsp; I will come back with a revised =
version for=20
you guys to comment on.</SPAN></FONT></DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D645144313-07022003></SPAN></FONT>&nbsp;</DIV>
<DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
class=3D645144313-07022003>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 4:36=20
  PM<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>Keenan,=20
  <P>I hope I saved you some work or maybe I made it more complicated.=20
  <P>Good luck,=20
  <P>Ken=20
  <P>&nbsp;<B><I>"Akin, Keenan L" =
&lt;keenan.l.akin@boeing.com&gt;</I></B>=20
  wrote:=20
  <BLOCKQUOTE=20
  style=3D"BORDER-LEFT: #1010ff 2px solid; MARGIN-LEFT: 5px; =
PADDING-LEFT: 5px"><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 =
Transitional//EN">
    <META content=3D"MSHTML 5.00.3315.2869" name=3DGENERATOR>
    <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>&nbsp;</DIV>
    <DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
    class=3D581290914-06022003>You make excellent points.&nbsp; That is =
why I send=20
    out ideas such as this for sanity checks.&nbsp; Sometimes you can be =
too=20
    close to the problem and not see something =
obvious.</SPAN></FONT></DIV>
    <DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
    class=3D581290914-06022003></SPAN></FONT>&nbsp;</DIV>
    <DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
    class=3D581290914-06022003>Thanks for your =
input,</SPAN></FONT></DIV>
    <DIV><FONT color=3D#0000ff face=3DArial size=3D2><SPAN=20
    class=3D581290914-06022003></SPAN></FONT>&nbsp;</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=20
      7:54 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=20
      port makes it harder to move in or out.That is all you need. But =
the need=20
      to vent the air to the other side I don't follow. Just restricting =
the air=20
      from going in or out of one port will do the same thing. Then have =
the FF=20
      solenoid pluse 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=20
      of 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=20
      movement will require force in that direction proportional to the =
air=20
      speed and by trimming you relieve the force pushing back.=20
      <P>Ken=20
      <P>&nbsp;<B><I>Keenan Akin &lt;kakin@yhti.net&gt;</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=20
        light <BR>force). As the airspeed increases, the valves starts=20
        restricting the <BR>flow proportionally, requiring a higher =
force to=20
        move the stick <BR>(representing aero forces on the control =
surfaces).=20
        Remember, I am <BR>building a WWII fighter, not a fly-by-wire =
jet. The=20
        solenoid valve is <BR>just there to provide pressure "pulses" in =

        response to force feedback <BR>signals.<BR><BR>Hope I made=20
        sense.<BR><BR>Keenan<BR><BR><BR>Ken Schlote wrote:<BR><BR>&gt;=20
        Keenan,<BR>&gt;<BR>&gt; I'm not quite sure why you are using air =

        pressure to increase the <BR>&gt; force of a stick. If you are =
going to=20
        use a cylinder then just adjust <BR>&gt; the flow entering or =
leaving=20
        the cylind! ! ! ! er! ! . Example: By closing the <BR>&gt; rear =
port you=20
        either have to pull a vacuum or pressurize the cylinder <BR>&gt; =
which=20
        stops you from moving the shaft because the air can not escape =
<BR>&gt;=20
        or enter. Adjusting the flow leaving or entering allows the =
shaft to=20
        <BR>&gt; move but with more force.<BR>&gt;<BR>&gt; A "V notch =
port" will=20
        do the job. (see attachment). As the V notch <BR>&gt; plug is =
pulled out=20
        of the port more air can escape or enter letting <BR>&gt; the =
shaft move=20
        with less force. As it moves in, the force increases <BR>&gt; =
because=20
        the size of the port decreases. This can all be done with one =
<BR>&gt;=20
        servo and cylinder per axis.<BR>&gt;<BR>&gt; Hope this helps.=20
        Questions?<BR>&gt;<BR>&gt; Ken<BR>&gt;<BR>&gt; "Akin, Keenan L"=20
        <KEENAN.L.AKIN@BOEING.COM>wrote:<BR>&gt;<BR>&gt; Okay=20
        folks,<BR>&gt;<BR>&gt; Here is my current concept of a pneumatic =
force=20
        feedback actuator<BR>&gt; for my pit. There would be two of =
these=20
        actuators attached to the<BR>&gt; stick (one ! pi! ! tch ! a! ! =
xis, one=20
        roll axis).<BR>&gt;<BR>&gt; &lt;&gt;<BR>&gt; The servo driven =
valve uses=20
        airspeed data to modulate the airflow<BR>&gt; from one side of =
the=20
        cylinder to the other (caused by moving the<BR>&gt; stick). For =
example,=20
        at higher airspeeds, the flow will be<BR>&gt; restricted, =
causing the=20
        stick to be harder to move.<BR>&gt;<BR>&gt; The solenoid valve =
ports=20
        pressurized air to one side of the<BR>&gt; cylinder or to the =
other only=20
        when a force feedback signal directs<BR>&gt; it. Otherwise, it =
is=20
        closed.<BR>&gt;<BR>&gt; Thoughts? Questions?<BR>&gt;<BR>&gt;=20
        Keenan<BR>&gt; &gt; ATTACHMENT part 2 image/gif =
name=3Dffactuator.gif=20
        <BR>&gt;<BR>&gt;<BR>&gt;=20
        =
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