JOY RIDER Flight Simulator

Head-operated view switcher.
Joyrider flight simulator. 
Feedback joystick for roll and pitch. 
Front of cockpit. 
Four-Axis electric-spinup gyro. 
   At one point we decided a project had to involve the technology of
virtual reality.  We would start by simulating a roller-coaster ride and
airplane flight.  So we got a 486DX2/66 computer with 8M RAM, 213M hard
drive, game port, sound card and speakers.  We bought every good flight
simulation program we could find at the time, several good joysticks and
several good VR books with software included.  Later we added a CD-ROM
drive and got some great coaster-ride videos.  Today, most everything
could be replaced by a laptop.
                 Head-Operated View Switcher 
   This was the first step in virtual reality.  It was to take the place
of the view-selector keys in the computer flight simulations. As you turn
your head right, your gaze is to the left, so the left view is on the
monitor.  The wires are soldered in parallel to the keyboard keyswitches.
We got a second keyboard to use in the cockpit.  But all game vendors use
different keys for views.  Some vendors even use different keys for their
different flight sims.  And some punish you by making you use multiple
keystrokes. So either select your best game or use programmable keys.
   The hat switch on the Thrustmaster FCS, which can be used in Comanche
and Aces of the Pacific, is a five-position "mini-joystick". It can be
replaced by the head-switcher.  There are eleven wires going to the FCS.
(one is ground, one is unused)  Five resistors are on the five-position hat
switch, which uses two of the eleven wires.  The two stick pots use three of
the wires (one is common to both pots).  The other wires go to buttons or the
trigger.  You could add a throttle pot to your cockpit.  The CH Flightstick
Pro has a better feel than the FCS, plus a handy throttle.
                The JOYRIDER Flight Simulator
   This is an involved project!  It requires several skills that you
may not possess if you're a computer and electronics person.  Such as
welding and machine-shop ability.  Plus, at present the simulator only works
with games that "follow the stick".  (Comanche Gunship, LHX and Aces of the
Pacific Navy planes)  As you move the joystick, the chair moves, just like
the plane would move. (That's the reason it's called the JoyRider.)  But if
you center the stick, the chair and the view stabilize, unlike real airplanes.
In real planes, you must move the stick back past center to stabilize.
   You will have to extend your keyboard and monitor cables to ten or
twelve feet.  You'll have to run the 16-gauge motor-power wires to a switch-
joystick at the pilot's position.  These are two 15-amp DPDT spring-
centering, center-off switches that turn the motors clockwise or counter-
clockwise, depending on which way the switch-joystick is moved.  This is
simple, but has no feedback.  If you hold the stick too long, the chair
bumps against its end stops.  Pots on the chair are read into the software
like joystick pots.
   Our present version has feedback, but it is also more involved.  You
move the chair joystick.  The chair moves to match the stick position and
stops by itself at that position.  Pots on the chair are read into the
software like they were without feedback.
   Hopefully the software vendors will soon output parallel words
representing the "state vector" to the printer port that will control the
cockpit motors.  But it isn't a simple matter to compute which way to
have the motors turn!
   Drive can be "gate closer" gearmotors.  Drive systems can be
tire-and-ring, chain-and-sprocket, cable-and-drum, belt-and-pulley, etc.
This is up to your ingenuity, price range and parts availability.
   You can also decide if you want to only have limited degrees of
tilt.  You could have a much simpler and smaller system like a cockpit
on a tilting platform, rocking on a trailer hitch ball.  Or you could
use two pairs of rockers at right angles, pulling the cockpit by cables.
We considered full 360 degree motion as well as limited-motion "keep-it-
simple", but we decided on a compromise, 180 degree.  You can make your
cockpit with only two degrees (axes) of motion, which makes it lower,
cheaper and lighter.  We discovered that yaw motion isn't really necessary,
so we disabled it later.
   The chair bearings are always the pitch axis.  The fork bearing is
roll if you haven't pitched up or down too much.  If you have pitched
up or down ninety degrees, the base spindle-and-hub bearing is now your
roll axis!  (Normally the base would be the yaw axis.)  So you can see
there are some complications you have with a simulator that you don't
have in a real airplane.  These things would have to be programmed into
the software.  The only way to avoid this complication would be to have
the simulator cockpit completely independent and inside a hollow sphere,
driven by pivoting wheels that ride on the inside of the sphere.
   Locate the chair bearings on the fork last.  This will determine the
balance, which should be neutral in all axes.  Have a dummy monitor
mass, all motors and the counterweights mounted.  Use clamps temporarily.
Put an average-weight person in the chair.
   We have discovered several things about motion-sensation feedback.
First, when the "ground" is ambiguous on the screen, gravity will tell
you how you're oriented by the "seat of your pants".  The sensation of
acceleration is simulated by a tilt upward while the monitor shows no
such tilt. Only initial acceleration is needed to make you think you're
moving continuously if the screen shows continuous movement.  Only a
fraction of the angular tilt is necessary to make you think you're
facing straight up or down.  Notice when you are in the amusement park
or mall simulators and you think you're looking straight down.  Then
notice when you're outside watching it. It really only tilts a fraction
of the angle it seems like.  Which brings up an interesting observation.
Anyone standing behind our simulator soon notices that the horizon on
the screen always stays horizontal!
   Pilots and virtual reality people tell us that of all the senses,
3-D color vision is far and away the most important mind window. Then
spatial sound, kinesthetic sense, touch (plus wind-in-the-face),
G-forces and finally smell.
   A VGA-to-TV converter with a video transmitter could send the cockpit
view to a battery-TV on the simulator.  That leaves only the keyboard and
joystick wires to route to the computer. Lots of options to try. This
appliance will definitely be a must-have gadget in the near future.