Newsgroups: comp.robotics
Path: brunix!sgiblab!swrinde!elroy.jpl.nasa.gov!ames!aio!l44db!mike
From: mike@l44db.jsc.nasa.gov (Mike Ross)
Subject: Re: Fast/Flexible Manipulators 
Message-ID: <1993Nov29.203443.12741@aio.jsc.nasa.gov>
Keywords: Fast, Flexible, Manipulators
Sender: usenet@aio.jsc.nasa.gov (USENET News Client)
Organization: Lockheed Engineering & Sciences Co.  Houston, TX.
References: <1993Nov23.124719@IASTATE.EDU> <1993Nov24.132414.29615@aio.jsc.nasa.gov> <CH06wA.Dpr@ecf.toronto.edu>
Date: Mon, 29 Nov 1993 20:34:43 GMT
Lines: 34

In article <CH06wA.Dpr@ecf.toronto.edu> hertz@ecf.toronto.edu (Roger B Hertz) writes:
)In article <1993Nov24.132414.29615@aio.jsc.nasa.gov>,
)Mike Ross <mike@l44db.jsc.nasa.gov> wrote:
)>
)>Manipulators designed for space operations must be lightweight, since it
)>costs $10000 to get each pound into orbit!  They don't need to be fast,
)>but they do need to be able to do with low power.  
)
)Wait a minute!  Since when is there requirement for sluggishness in space?
)Would not a faster system be desireable?  Granted that present speed
)on the SRMS is limited by stopping distance, and response time limited
)by the bandwidth of the joint controllers, but wouldn't an overall
)productivity increase be desireable?  Even a tiny bit?
)
There is no REQUIREMENT for sluggishness, there IS a requirement for
crew safety, low stopping distances AND loads, and the existence
of poor viewing conditions.  Don't forget the 'pucker factor'! 
When the astronauts move those big payloads around in the simulation,
they go considerably faster than when there's REAL hardware moving around
on the other side of that Orbiter window.

All else aside, however, faster manipulators would be a godsend.  Have
you ever watched flight tapes of the RMS in action?  It's like watching
paint peel.  We tape it and play the VCR 8 times faster just to see
the dynamics.

-mike


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