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Robots |
Hand |
Phantoms |
VR |
Mobile Robots |
Image proc. |
Robot arms
In the UR vision and robotics lab we have two 6 axis PUMA 760 series
robot arms,
Bill and Hillary. They are larger versions of the perhaps more
popular 560 series arms. The joints are driven by geared electric motors.
Each motor is controlled by a digital controller. The robots come
with a rather bulky control rack containing the power supplies
servo amps, controllers, and an lsi11 central processor. Unimation, the
manufacturer delivers the VAL robot programming language which
runs on the lsi11. In most of our work we don't use VAL. Instead
we use RCCL, which we have ported to run under Solaris threads on
an 8 processor Sun Sparcrcenter 2000. Integration with the other
vision lab computers is provided through a distributed robotics
library implemented in PVM, and high level acess is availible
through MATLAB interfaces to the underlying C-code.
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Hillary (left), the smaller of the two is a PUMA 761. The elbow link is
slightly shorter than Bill's.
Bill (right) is the first of our PUMA's. It is a 762 with the
extended (850mm) elbow. Click on the images to see larger robot
pictures.
Local libraries: |
Robot hand
We have a four finger Utah/MIT hand. The hand has 16
actuated joints. Each is pneumatically driven by two antagonistic
tendons. The tendons go through a long remotizer, which allows the
hand to rotate approximately like a human wrist, but also makes
precise control of the fingers difficult.
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The hand is mounted on our PUMA 762, with the remotizer bolted
to the elbow link. This retains 5 of the 6 freedoms of the PUMA arm.
Only joint 6 rotations are significantly restricted.
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Force feedback devices: Phantoms
Haptics-enabled virtual reality (VR) applications are
much more compelling than graphics-only VR for many tasks
(e.g. games, picking and moving molecules and
driving simulators).
Haptic devices give you the sense of touch through applying forces on
certain parts of your body.
Traditional haptic devices ( like exoskeletons )
are bulky, expensive and inconvenient to use or program.
Originally developed at MIT,
Sensable Technology's PHANToM interface is a breakthrough in this field and
has gained wide acceptance in research communities.
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PHANToM is a desktop device.Basically, the user places his fingertip in a thimble. In each cycle
first the fingertip's 3D position is sensed and then a 3D force vector is computed and applied to the fingertip.
This whole cycle is repeated at a frequency of about 1000 Hz to give user a smooth (no vibrations
felt) force feedback when he moves his finger across space.
For more information ,
the following links can give you a tour of the
features of and the many of the exciting on-going and future
researches enabled by PHANToM.
Our virutal reality lab currently has four PHANToMs connected to SGIs for studying how human visuo-motor systems work under controlled virtual environments. Another promising research direction is to explore the use of PHANToM as a programmable force-feedback 3D input device such as a 3D accelerator for navigating in virtual environments. |
Virtual Reality
VR Lab Hardware Components
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Mobile Wheelchair Robots
We have two
wheelchair mobile robots purchased from KIPR, which have been enhanced with
extra sensing and computational power by our mobile robotics group.
Description
of UR mobile robot hardware and software
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Image processing hardware
We have two generations of Datacube image processing hardware. An
older MV10 board system is on the way out (the boards biting the dust
one after another), and a newer mv 200 is being phased in. Either
system is capable of a variety of operations at frame rate, such
as convolutions, multiplexing, logical operations. Two advantages
of the newer systems are: (1) It has an electronic video bus switch
(instead of the cable mess seen to the right in the image). (2) One
can write "pipelined" code using Imageflow. A
Datacube MV200 and ImageFlow User's Guide and several
example programs are availible.
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