Conference 7.286::space

706.0. "NASA Inventor of the Year announced" by PRAGMA::GRIFFIN (Dave Griffin) Tue Feb 19 1991 17:31

From: [email protected] (Peter E. Yee)
Date: 19 Feb 91 04:25:42 GMT
Organization: NASA Ames Research Center, Moffett Field, CA

Kelly O. Humphries
Jonhson Space Center, Houston                                                                     
February 14, 1991                      
(Phone:  703/483-5111)


RELEASE:  91-26

NASA INVENTOR OF THE YEAR ANNOUNCED  


     Johnson Space CenterUs Leo Monford, NASA's Inventor of the Year, is 
determined to make the Space Shuttle's robot arm even more useful 
than it is, and his inventions could revolutionize orbital docking and 
robotics use.

     The invention that earned him the award is a "Docking Alignment 
System,  Monford calls it the Targeting and Reflective Alignment 
Concept, or TRAC.

     By itself, the new precision alignment system is a significant 
improvement. But used in concert with another of Monford's inventions, 
a Magnetic End Effector, it could change 
the shape of future robot arms, satellites and space stations.

     Monford, who works in the New Initiatives Office's Space Servicing 
Systems Project Office, is the first JSC employee to receive the 
Inventor of the Year award since its inception in 1980. The award will 
be presented March 28 at a NASA Headquarters 
ceremony,  according to NASA General Counsel Edward Frankle, who 
announced Monford's selection Feb. 5.

     "My job is to come up with innovative thoughts and technologies and 
stimulate others into producing those products," Monford said. "I 
honestly can't think of an award I would desire more than this one."

     TRAC utilizes a television camera mounted inside the arm's end 
effector and a monitor on the Shuttle's aft flight deck, both with 
alignment marks and a flat, mirrored target marked with cross hairs on 
the target object. It has been tested extensively at the manipulator 
development facility and is able to routinely insert square pegs into 
square holes with only  0.03 of an inch clearance.

   Here's how it works. An astronaut operating the remote manipulator 
system from the aft flight deck moves the arm to within range of the 
fixed-focus television camera inside the arm. The operator makes 
translational corrections with the arm until the cross hairs on the 
target and the monitor line up. 

     Then, the operator uses rotational controls until the camera is able 
to see its own image. Since the camera can see only directly in front of 
itself, it will not see its own image until the end effector and the 
target are perpendicular to each other. When the camera can see itself 
and the cross hairs are lined up, alignment is complete.

     "It's like looking through a rifle scope," Monford said.  "Once you 
understand the idea of aligning the cross hairs, it just comes naturally 
to you."

     The existing alignment system uses a target with a protruding post. 
The main advantage of Monford's system is that the target is flat. Many 
proposed space operations for the Shuttle's arm or a space station arm 
involve stacking and unstacking objects for construction purposes.

     "When you try to make things stack up, a protruding target gets in 
the way," Monford said. The beautiful thing about the TRAC system, he 
added, is that it works perfectly with the operator's hand controllers, 
which maneuver the arm through separate rotational and translational 
controls.

    The first practical application of TRAC will be on STS-37, as a part 
of Development Test Objective 1205, "TRAC Application for RMS 
Alignment/Deflection Measurements." TRAC will be used to provide 
precise data on the amount of "play" in the remote manipulator system 
when a space walking astronaut applies force to the oustretched arm. 
The targeting system will gather data that would be difficult or 
impossible to gather otherwise.

     Monford said researchers at Texas A&M, his alma mater, are working 
on automating TRAC. Instead of cross hairs, the automat system uses 
corner cubes on the target that reflect light back only in the direction 
of its origin, similar to bicycle reflectors and a light-emitting diode on 
the camera lens. A computer lines up the flood-lit corner cubes to 
determine when the arm is perpendicular to its target. When the camera 
can see the reflection of the LED on its lens, the computer will know 
the alignment is exact.

     "It's really a generic concept. It has very broad application," he said, 
explaining that it can provide a precise reference point for intelligent 
robots that need to perform exacting tasks on three-dimensional 
surfaces.   Put the TRAC system together with Monford's Magnetic End 
Effector, patent pending, and the possibilities grow.

     The MEE is a potential replacement for the Standard End Effector, 
which grapples payloads through electro-mechanical means, using 
cables to snare a protruding grapple fixture. The MEE, with no moving 
parts, uses electro-magnetic force to "clomp onto" a plate made of 
ferrous metal  attached to the payload. The metal plate shares the 
advantage of flatness with the alignment target, and the MEE's 
centerline camera would allow the docking plate to double as the target 
plate for the TRAC system.

     Monford's smaller, lighter MEE is two-fault tolerant both in 
grappling and releasing payloads and requires no regularly scheduled 
maintenance or pyrotechnic safety release devices.

    Proposed MEEs would give different sized arms the capability to 
grapple common target plates, add the ability to transfer both power 
and data to payloads and provide a method of attaching a variety of 
power tools that could help alleviate the need for some extravehicular 
activity space walks by astronauts. "I think in the space station era, 
this type of an end effector will be baselined," Monford said.

     The TRAC, MEE, a JPL Force Torque Sensor that provides a 
representation of forces and moment on the arm, and a Carrier Latch 
Assembly that uses electromagnetic force to help hold satellites in the 
payload bay, are scheduled to fly as part of  the Dexterous End Effector 
Flight Demonstration on STS-58.   "I'm looking forward to some other 
exciting flight experiments that would leapfrog from this one."