[simpits-tech] ACES II Replica, G- cueing Seat.
Chris Woodul
simpits-tech@simpits.org
Sun, 7 Jul 2002 11:30:24 -0500
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Hi Brian
The company I work for produces my design for High Fideltiy Replica =
Ejection Seats ( among other things)
Some of these seats are static, and some are designed to be G-Cueing =
systems. I dont build the G-Cueing hardware, nor do we do the =
algorythims. We just make all the mechanical parts. We are Cranfield =
Aerospace's manufacturer of seat systems. Cranfield is in the UK and are =
the undisputed king of G-cueing seats. Cranfield's seats utilize =
electric motors and loadcells and LDVT's all tied in with a computer and =
some serious programing to create the essence of G on multiple axis's.
Older G-cueing systems from the US utilized Pneumatic bladders and fast =
acting valves, but fell into the trap of compresiblity,and latency. Some =
seats even used 1800psi hydraulic actuators ( yikes) to do the job.=20
I am working with a company in California which has a very unique =
Pneumatic valve which may change the problem of the speed of pneumatics =
in actuating pressure pads in seats.
Seats move very little to impart the sensation of movement. As noted in =
a later message thread by Marc W. there are some systems ( Sogitec) =
which impart a load on the pilots helmet to simulate the increased =
"weight" of your Bone Dome as you pull G's ( particulary noticable in a =
9G capable jet like the Viper)
Other functions tighten or loosen straps on the pilot and the most =
significant axis of movement is G - Z ( vertical axis..ie. thru your =
head to your toes)
When you pull G's your body scrunches down due to the loading so your =
eyepoint lowers, also the "hardness" of the seat pan changes.
When you deploy airbrakes ( or wheel brakes) you surge forward, when you =
accelerate you surge backward...yawing motions produce side to side =
sway.Even the Buffet of a stall or the intense vibration of an M-61 =
Vulcan cannon firing shakes the pilot...all of these are important =
clues.
In addition to this the pilot is connceted to a G-Valve with his G-Suit. =
The pilot has a scaled down G-response so the suit wont blow his blood =
vessles as he is really sitting in an "office environment" in a constant =
1 G. The pilot does feel a variable scheduled squeezing on him which =
also is a nice clue to how much G he is putting on the jet.
I have flown in about five military jet warbird aircraft, and fly =
aerobatics myself as well. I wish everyone could understand just how =
distracting even a constant 5 G's can feel. Nine G's would put most of =
us to sleep! People tend to put on alot more G in a sim when they dont =
have any cues as to how much they are really pulling ( besides a G meter =
indication)
I would love to see how your system comes out. One thing you need to do =
is find a way to evacuate the bladders quickly after filling them for =
each cue response, and remember that you only need to move the pilot =
fractions of an inch to get the job done.
Thanks,
Chris Woodul
I will try to send Gene pictures of our High Fidelity F/A-18 NACES and =
F-16 ACES II seats just so you can see what they look like. Id love to =
hear feedback on them from this crowd!
----- Original Message -----=20
From: Brian West.=20
To: Simpits-tech.=20
Sent: Saturday, July 06, 2002 3:15 PM
Subject: [simpits-tech] ACES II Replica, G- cueing Seat.
Chris Woodul, =20
A couple of days ago you let slip a mention of a G-cueing seat, what =
can you tell us?=20
I have a design sketched out using low pressure pneumatics and =
football bladders in the seat sides and cushion.
If you have been down this road already I would love to hear.
Best regards, Brian West.
.
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<DIV><FONT face=3DArial size=3D2>Hi Brian</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>The company I work for produces my =
design for High=20
Fideltiy Replica Ejection Seats ( among other things)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Some of these seats are static, and =
some are=20
designed to be G-Cueing systems. I dont build the G-Cueing hardware, nor =
do we=20
do the algorythims. We just make all the mechanical parts. We are =
Cranfield=20
Aerospace's manufacturer of seat systems. Cranfield is in the UK and are =
the=20
undisputed king of G-cueing seats. Cranfield's seats utilize electric =
motors and=20
loadcells and LDVT's all tied in with a computer and some serious =
programing to=20
create the essence of G on multiple axis's.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Older G-cueing systems from the US =
utilized=20
Pneumatic bladders and fast acting valves, but fell into the trap of=20
compresiblity,and latency. Some seats even used 1800psi hydraulic =
actuators (=20
yikes) to do the job. </FONT></DIV>
<DIV><FONT face=3DArial size=3D2>I am working with a company in =
California which has=20
a very unique Pneumatic valve which may change the problem of the speed =
of=20
pneumatics in actuating pressure pads in seats.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Seats move very little to impart the =
sensation of=20
movement. As noted in a later message thread by Marc W. there are some =
systems (=20
Sogitec) which impart a load on the pilots helmet to simulate the =
increased=20
"weight" of your Bone Dome as you pull G's ( particulary noticable in a =
9G=20
capable jet like the Viper)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Other functions tighten or loosen =
straps on the=20
pilot and the most significant axis of movement is G - Z ( vertical =
axis..ie.=20
thru your head to your toes)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>When you pull G's your body scrunches =
down due to=20
the loading so your eyepoint lowers, also the "hardness" of the seat pan =
changes.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>When you deploy airbrakes ( or wheel =
brakes) you=20
surge forward, when you accelerate you surge backward...yawing motions =
produce=20
side to side sway.Even the Buffet of a stall or the intense vibration of =
an M-61=20
Vulcan cannon firing shakes the pilot...all of these are important=20
clues.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>In addition to this the pilot is =
connceted to a=20
G-Valve with his G-Suit. The pilot has a scaled down G-response so the =
suit wont=20
blow his blood vessles as he is really sitting in an "office =
environment" in a=20
constant 1 G. The pilot does feel a variable scheduled squeezing on him =
which=20
also is a nice clue to how much G he is putting on the jet.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>I have flown in about five =
military jet=20
warbird aircraft, and fly aerobatics myself as well. I wish everyone =
could=20
understand just how distracting even a constant 5 G's can feel. Nine G's =
would=20
put most of us to sleep! People tend to put on alot more G in a sim when =
they=20
dont have any cues as to how much they are really pulling ( besides a G =
meter=20
indication)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>I would love to see how your system =
comes out. One=20
thing you need to do is find a way to evacuate the bladders quickly =
after=20
filling them for each cue response, and remember that you only need to =
move the=20
pilot fractions of an inch to get the job done.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Thanks,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Chris Woodul</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I will try to send Gene pictures of our =
High=20
Fidelity F/A-18 NACES and F-16 ACES II seats just so you can see what =
they look=20
like. Id love to hear feedback on them from this crowd!</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV> </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dbcw@palma.infotelecom.es =
href=3D"mailto:bcw@palma.infotelecom.es">Brian=20
West.</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3DSimpits-tech@simpits.org=20
href=3D"mailto:Simpits-tech@simpits.org">Simpits-tech.</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, July 06, 2002 =
3:15=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [simpits-tech] ACES II =
Replica,=20
G- cueing Seat.</DIV>
<DIV><BR></DIV>
<DIV><FONT color=3D#000000 size=3D2>Chris Woodul, </FONT></DIV>
<DIV><FONT size=3D2>A couple of days ago you let slip a mention of a =
G-cueing=20
seat, what can you tell us? </FONT></DIV>
<DIV><FONT size=3D2>I have a design sketched out using low pressure =
pneumatics=20
and football bladders in the seat sides and cushion.</FONT></DIV>
<DIV><FONT size=3D2>If you have been down this road already I would =
love to=20
hear.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Best regards, Brian =
West.</FONT></DIV>
<DIV>.</DIV>
<DIV> </DIV></BLOCKQUOTE></BODY></HTML>
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