[simpits-tech] ACES II Replica, G- cueing Seat.

Tue, 22 Oct 2002 22:42:15 -0500

Hi Craig,

Now you got my curiosity going! Id love to try it out and feel it in action.
I have not heard of anything similar either, so congradulations on coming up
with something really cool...and potentially very useful.
Some people like Sogitec in France who make G Cueing seats have cables that
attach to rollers on a special helmet which loads up the helmet with a
"crude" Z axis pulling motion that can only simulate Positive G loads on
helmet. I think I can visualize your system being much more real feeling,
and again in a VR helmet environment, a real plus!
Contact me on my work Email- cwoodul@fain.com and tommorow I would like to
put you in contact with an engineer at a company in California that I do
bussiness with who has a propietary valve system for use with pnumatics. I
think you two would have an interesting time talking.
If ever I am in your neck of the woods, Id love to try it out!

Thanks,

Chris Woodul

----- Original Message -----
From: "Craig Rochester" <johncraigroch@msn.com>
To: <simpits-tech@simpits.org>
Sent: Tuesday, October 22, 2002 10:31 PM
Subject: RE: [simpits-tech] ACES II Replica, G- cueing Seat.

> "Light and airy, organic if you will" that describes what I got from the
I/V
> transducer.  I was very surprised that I didn't have problems with
latency,
> dampening and "squishiness".  I thought for sure I'd have to build a
complex
> closed loop system with feedback from head/helmet pressure(that'd be a
> bitch).  The I/V's maintains a very precise pressure in the system.  The
> back-pressure produced by moving my head against the cylinder apparently
is
> sufficient feedback to do the trick.  It felt like I had a book on my head
> and not like being attached to a spring.  I haven't tried it with Falcon4
> yet as I'm too cheap to buy an $800 analog I/O card.  I may try the G-Suit
> servo regulator(essentially the same thing) in place of the I/V.
>
> Verbal descriptions only go so far. I've thought about doing some
> quantitative measurements of the performance.  But hooking up the load
> cells, pressure transducers, displacement transducers, and interfacing
them
> to a data logger is more complicated than the rig. :)  Maybe it'd be worth
> it for the "peer review".
>
> I did a lot of web searches, particularly at the US Patent Office site,
and
> have yet to find and instance of an I/V used this way.  I probably just
> haven't looked in the right places.
>
> I really appreciate your feedback.  It's so inspiring to have someone talk
> so fluently and insightfully about the nitty-gritty of this.
>
> Thank You,
>
> Craig R.
>
> -----Original Message-----
> From: simpits-tech-admin@simpits.org
[mailto:simpits-tech-admin@simpits.org]
> On Behalf Of Chris Woodul
> Sent: Tuesday, October 22, 2002 10:50 PM
> To: simpits-tech@simpits.org
> Subject: Re: [simpits-tech] ACES II Replica, G- cueing Seat.
>
> Hi Craig,
>
> Cranfields seats are very mechanical in thier approach to cuaseing parts
of
> your body to move. They use strap and belt tensioning, pad movement, and
> Z-Axis movement of the seat all in combination with the G Pants. By the
way
> to anyone doing G pants simulation..DO NOT SHEDULE the pants to inflate to
> the real aircraft values, if you do that you can collapse the capilaries
in
> the persons legs. When you are pulling real G's its quite differnt than
> sitting in a 1G environment.
> Flight simulation GValves use a de-rated shedule to simulate the inflation
> of the pilots actual G pants worn into the cockpit.
>
> I read your webpage and I think its really clever. I think if you can
> smoothely push and pull on the helmet that it could be quite "intuitive"
> that there are forces actiing on you, especially since you are using a VR
> environment with your system.
> I am a real pilot and I fly partly with my Butt ( not just my inner
ear..and
> I know that other pilots on this forum will agree they do to) but even if
> you are just acting on the head I think that the human brain is very
> adaptable to feeling the inputs you will be imparting on it. I think some
> important factors to consider is to "unload" the head tracking mechanics
> sort of like a STEADY CAM so that none of the friction loads or weight
loads
> of the mechanism get translated thru the gimbals. I also think that you
need
> a fast enough system to kill any latency in the actuators..any delay in a
> cue will kill the suspension of reality and possibly cause "simulator
> sickness" on  the user. Another factor is dampening any of the actuator
> movements to feel Light and airy, organic if you will. You dont want the
> movements to feel like a FIRM pick and place robot. Planes fly fluidly (
> albiet with lots of force in planes like the viper.
> Are you using any kind of load cells in the unit to measure output, and is
> it a closed loop or open loop system?
> Keep me posted, I will enjoy your progress!
>
> Thanks,
>
> Chris Woodul
>
> ----- Original Message -----
> From: "Craig Rochester" <johncraigroch@msn.com>
> To: <simpits-tech@simpits.org>
> Sent: Tuesday, October 22, 2002 9:03 PM
> Subject: RE: [simpits-tech] ACES II Replica, G- cueing Seat.
>
>
> > Hi Chris,
> >
> > Thank you for you feedback on the G-cueing, it's a real thrill to have a
> pro
> > give feedback on this.  Most of the time I feel like I'm working in a
> > vacuum.
> >
> > Thanks for the link, I hadn't seen the Cranfield site.  I noticed they
> > mentioned loading.  Is this the shoulder strap loading, or maybe helmet
> > loading.  I'm interested in pursuing a 3 DOF(maybe 6) helmet loading
> system.
> > I've done a little preliminary experimenting:
> > http://pages.zdnet.com/johncraigrochester/vrvision/id12.html (photos at
> > bottom).  I'm already looking to do a HMD with head-tracking using a
boom
> > attachment to my helmet, so adding actuators to the joints is a logical
> > extension(at least to me :)).  I've had promising results using an
> > electro-pneumatic regulator(V/P).  I rigged up a crude 6 DOF boom
attached
> > to a helmet and mounted a long stroke pneumatic cylinder vertically to
the
> > rotation gimbal.  I could move my head in all DOFs and still get a very
> > constant applied force.  I'm hoping the performance will be good enough
to
> > apply simulated inertial and G-forces,  and also minimize the weight and
> > inertia of the boom.  I'm thinking I can calibrate the thing to "float".
> >
> > End of rambling,
> >
> > Thanks again,
> >
> > Craig R.
> >
> >
> >
> > -----Original Message-----
> > From: simpits-tech-admin@simpits.org
> [mailto:simpits-tech-admin@simpits.org]
> > On Behalf Of Chris Woodul
> > Sent: Tuesday, October 22, 2002 9:17 PM
> > To: simpits-tech@simpits.org
> > Subject: Re: [simpits-tech] ACES II Replica, G- cueing Seat.
> >
> > Hi Craig,
> >
> > I enjoyed reading the message thread you directed me to.
> > The Company I work at makes the SIMULATED SEAT it self and CRANFIELD
> > AEROSPACE in the UK makes the motor units, mechanisms and computers that
> run
> > the thing. We dont do the algorythms for them where I work. The
Cranfield
> > seat is purely electric, except for the G-Valve assy for the Pilots
> G-suit.
> > I do know that on the older G-cueing seats that used Pneumatics that the
> > ability to evacuate the air that has been piped into the zone cushions
was
> a
> > problem. I think you guys are quite smart and are definetly doing some
> cool
> > stuff.
> > I dont have any of the numbers on operations of the unit ( and If I did,
I
> > am bound by a Non Disclosure Agreement with Cranfield Aerospace) If I
can
> > find any thing like what you are looking for in other industry
literature
> I
> > will most certainly forward it to you.
> > One neat thing about a G-cueing seat is that there is no need for
WASHOUT,
> > like there is with a 6-DOF Motion Platform. People need to understand
that
> > you cannot Simulate actual "G" with a G-cueing seat. You can however
> > demonstrate the displacements and pressures on your body that are nice
> CUEs
> > to what is happening.
> > The Cranfield people tell me that people who fly fighters "get it" but
> > non-pilots dont always understand the cues being imparted on them.
> > Other neat cues that are in the seat are accelerations, decelerations
( ie
> > Braking and Afterburner use) also Gunfire High Frequency Vibration, and
> > other areodynamic cues.
> > If you havent already been there in your own pursuits of making a
G-Cueing
> > seat, here is the link to Cranfield.
> > http://www.cranfieldaerospace.com/spg/simulation.htm
> >
> > Keep up the good work on your system, I am really impressed. As always
> there
> > are some really inovative and clever people on this fourm and thats why
I
> > love being a simpits member!
> >
> > Take care,
> > Chris Woodul
> >
> > ----- Original Message -----
> > From: "Craig Rochester" <johncraigroch@msn.com>
> > To: "Simpits-Tech@Simpits. Org" <simpits-tech@simpits.org>
> > Sent: Tuesday, October 22, 2002 3:40 PM
> > Subject: [simpits-tech] ACES II Replica, G- cueing Seat.
> >
> >
> > > Hi Chris,
> > >
> > > I've been reading through the archives and found your posts on the G-
> > Cueing
> > > seat.
> > > I've been working on a G-Suit pneumatic rig with some guys from
Norway.
> > See
> > > this forum
> > >
thread:http://www.simpits.org/forums/viewtopic.php?topicU&forum=1&start
> > >
<http://www.simpits.org/forums/viewtopic.php?topic=55&forum=1&start=15>
> > (go
> > > to bottom).  I worked and worked to get a "regulator" that would
exhaust
> > > quickly.  I finally stumbled on a rig that works well.  I use a "quick
> > > exhaust valve(QEV)" and a high capacity regulator.  The air exhaust is
> as
> > > fast as the supply.  Qualitative guestimates on performance:
> > > Range of supply pressure = 0-5 psig
> > > G-Force vs. G-Suit pressure- 1-9 G = 0-5 psig
> > > 9 G - 8 G(5-4.5 psig) decrease take about 0.1 sec
> > > 2 G - 1 G(0.5-0.0 psig) decrease take about 0.2 sec
> > > 9 G - 1 G(5-0.0 psig) decrease take about 0.75 sec
> > >
> > > The bottom line for me is the feel of the G-Suit.  I can feel 1/4 psi
> > > changes, and the changes feel intuitively correct when I fly Falcon4.
> But
> > > I'm not a pilot and have never pulled Gs.;)
> > > Do you have specs for the G-Seat latency requirements?
> > > Regards,
> > >
> > > Craig
> > >
> > >
> > >
> > > _______________________________________________
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