Re: MADEFAST Design, Trdeoffs, and Affordability

Ruzena Bajcsy <bajcsy@central.cis.upenn.edu>
Message-id: <199403071347.IAA20861@central.cis.upenn.edu>
To: dwhitney@MIT.EDU (Dan Whitney)
Cc: leifer@sunrise.stanford.edu, bajcsy@central.cis.upenn.edu,
        Bill Birmingham <wpb@eecs.umich.edu>,
        Susan_Finger@WYVERN.CIMDS.RI.CMU.EDU, rfr@cs.utah.edu,
        fertig@rpal.rockwell.com, martin@rpal.rockwell.com, davis@ai.mit.edu,
        sticklen@cbs.msu.edu, mcdowelj@cps.msu.edu, gruber@HPP.Stanford.EDU,
        fikes@HPP.Stanford.EDU, rz@cs.cornell.edu, cohen@cs.utah.edu,
        elks@msg.ti.com, ecks@msg.ti.com, fbp@andrew.cmu.edu, terk@cs.cmu.edu,
        weber@eit.com, mcguire@eit.com, dbrown@cs.utah.edu, sbj@wimpy0.psu.edu,
        wysk@ieman.tamn.edu, jln@draper.com, morgenstern@dri.cornell.edu,
        marty@eit.com, wachter@itd.nrl.navy.mil,
        "Glenn A. Kramer" <gak@eit.com>, cutkosky@sunrise.stanford.edu,
        petrie@sunrise.stanford.edu, toye@sunrise.stanford.edu,
        hong@sunrise.stanford.edu,
        "Greg Twiss" <greg_twiss@qm.is.lmsc.lockheed.com>,
        Kevin Lyons <klyons@cme.nist.gov>, Pradeep Khosla <pkk@arpa.mil>,
        "Peter F. Brown" <brown@cme.nist.gov>, Mike McGrath <mcgrath@arpa.mil>,
        kumar@central.cis.upenn.edu
Subject: Re: MADEFAST Design, Trdeoffs, and Affordability 
In-reply-to: Your message of "Mon, 07 Mar 1994 08:23:15."
             <9403071323.AA01989@MIT.EDU> 
Date: Mon, 07 Mar 1994 08:47:31 EST
From: Ruzena Bajcsy <bajcsy@central.cis.upenn.edu>


 >>I'm glad to see the "design" part of the program starting to take some 
 >>shape.  I'd like to add some other considerations that may stretch the 
 >>group a little but are a basic part of realistic design and may get 
 >>ARPA's attention:
 >>
 >>The specifications for a seeker include pointing accuracy and bandwidth.  
 >>These together mean that it should be able to find and lock onto a 
 >>target and keep hold of it even if it moves rapidly.  It should also be 
 >>able to report the target's heading in two angle dimensions accurately, 
 >>both when the target is apparently stationary and when it is moving.  It 
 >>should also be able to do this when the target is dim and hard to 
 >>detect.
Danny,
I could not agree with you more!!!
 >>
 >>These requirements "flow down" to particular design parameters like 
 >>gimbal motor torque, servo gain and damping, gimbal stiffness and mass, 
 >>rate gyro sensitivity,  bearing runout, sensor sensitivity (hence size 
 >>and weight), and assembled tolerances (do the two gimbal axes intersect? 
 >>do they intersect at the center of the sensor, etc.)
 >>
 >>There is an overall diameter and weight limit as well.  These limits 
 >>make it hard to meet the requirements above.  A cost limit will be even 
 >>harder to meet.  
 >>
 >>Altogether this mixed set of requirements will require tradeoffs to be 
 >>made between cost and performance.  This is a basic trade which is 
 >>little practiced in DoD work, though it is the main driver in commercial 
 >>work.  Developing collaborative tools to do tradeoffs would be a big 
 >>contribution as DoD strives to define what "affordability" means.

All above what you said is so much true and offers beatifull design research
problems!!
Right on,
Ruzena