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Galil Motion Control, Inc. · 800-377-6329 · www.galilmc.com
SMART MOVES SPOTLIGHTS
in 1.5 seconds. Because the cargo bay cam-
era can be loaded only once per flight, the
requirement dictated that one mile of film be
handled by the transport system. The film
and supporting reel weighed over 60 pounds.
The s-curve acceleration of the DMC-1560
controllers was important to control jerk and
assure smoothness under these conditions.
MSM also used the analog inputs on the
Galil controller to display power supply
variations for diagnostics. The cabin camera
is completely self-contained and includes the
six-axis motion controller. The auxiliary
RS232 port of the controller drives a 4x20-
character display so that the operator can
view important camera parameters.
Operation is easy and similar to that of com-
mon home video cameras.
According to MSM software designer,
William Nixon, "Galil was easy to program.
Every time we thought of something, Galil
had the `hooks' to accomplish it."
IMAX is a registered trademark of the IMAX Corp.
SM Design in Idaho was recently
selected by IMAX to develop two
easy-to-use three-dimensional
cameras to be used on space shuttle missions
starting in 1999. The first is a remotely con-
trolled system mounted in the cargo bay sec-
tion during space shuttle flights. The second
is a compact hand-held camera that will be
used either inside the crew cabin during
shuttle flights or onboard the international
space station after it becomes habitable. The
cameras will document space travel and the
building of the international space station.
MSM's lead electronic systems integrator,
John Stafford, selected the Galil DMC-1560
six-axis stand-alone motion controller to
help ensure success of the project.
The cameras were designed to replace
the current two-dimensional IMAX cameras
now used by NASA. The new 3D cameras
will make the IMAX movie images much
more exciting and realistic. The 3D nature of
the photographs will also provide a more
detailed record from which engineering data
can be extracted when needed.
MSM chose a Galil controller because of
the company's well-known expertise in
servo systems. Servo motors were chosen
over steppers because of high-speed and
acceleration requirements. In the past MSM
has developed its own controllers for various
projects but in this case the company did not
have time to develop one of its own.
However, there was no need--the Galil
DMC-1560 had all the high-performance
features MSM needed for the project.
The cargo bay camera was built using a
standard DMC-1560 controller with only
minor hardware modifications and custom
software provided by Galil. First and fore-
The IMAX 3D
cabin camera is completely
self-contained and includes a Galil
DMC-1560 controller.
MSM Design and Galil Gear Up for Space.
most, the portable cabin camera needed to
be compact. To accommodate the rigid space
requirements and to fit in an irregularly
shaped area inside the camera, Galil
designed a special DMC-1560 motion con-
troller with all six axes on a single board
measuring less than 12" by 9".
Two of the axes control lens
focus and the iris. Three axes
are used to transport the film,
including the film supply,
take-up and the camera drive.
On the cargo bay camera the
sixth axis is used to move a
turret that allows the operator to
select between three lens pairs.
The cabin camera controller's
auxiliary encoder inputs were used to pro-
vide input from manually operated encoders
to control lens focus and iris settings. The
math functions of the controller were used to
calculate focus distance and depth of field
information, which is shown on a digital dis-
play. Galil provided additional custom soft-
ware that allows a special electronic gearing
mode on the Galil controller. This mode was
used to gear the manual, auxiliary encoders
to the motor encoders resulting in very
smooth operation of the lens control motors.
The cargo bay camera remote control was
implemented using the Visual Basic package
from Galil. This allowed rapid development
of an easy to operate system complete with
diagnostic capability.
A standard 2D IMAX camera runs at 24
frames per second, which translates to just
over 5.5 feet per second of film speed. 3D
filming required the new space cameras to
transport film twice as fast, at 11.25 feet per
second. The film speed needed to be reached
"Galil was easy to program. Every time we thought of
something, Galil had the `hooks' to accomplish it."
M
