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C00002 00002				TECHNICAL PROPOSAL
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			TECHNICAL PROPOSAL

	

	
	To meet the specifications of solicitation No.4-35921, VICARM
proposes  to  deliver  a  modified  version  of  our  standard  model
"Stanford" six degree of freedom computer controlled manipulator.   A
specification  sheet for  this  standard manipulator  is enclosed  as
Attachment 1.  

	The  paragraphs which follow detail the general properties of
our   model  Stanford   manipulator   and   describe   the   proposed
modifications  to   enable  it  to  meet  the   requirements  of  the
solicitation.  Attachments A,   B,   and C are  layouts of our  model
Stanford manipulator with some of the proposed changes sketched in.


	1) The standard manipulator has the  required geometry and is
an option A  type, having a prismatic third joint. Base up (inverted)
installation is allowable for the standard manipulator. To completely
meet the  requirements of section 3.1,   the wiring paths  of the arm
will have to be redesigned to allow for internal routing of the seven
instrumentation wires.   This will require  extra shrouding to  allow
the wires  to pass around joint  5,  a special  housing for shrouding
the wire loop around the prismatic  joint and also a redesigned  path
thru joints  2 and  1. The  standard model  wire paths  are shown  in
Attachments  A and  B, along  with a  possible redesigned  layout. As
redesign to provide entirely internal wire paths will entail  quite a
bit of work, the details of this have been left out of this proposal.
It is anticipated that this will be a negotiable point, as no mention
is made  of a requirement  that motor,   brake,   potentiometer,   or
tachometer wires  be internal. The limits of  motion,  maximum speed,
and geometry  of our  standard  arm are  such that  these  particular
specifications are met  with no redesign,   provided the  duty cycles
are no  greater than typified by the  proposed acceptance tests,  and
minimum velocity specifications are for an unloaded arm.  To meet the
minumum velocity specifications at full load will require substantial
redesign.

	2) Our  proposed terminal device is our standard parallel jaw
hand (see Attachment C), which meets the requirements of section 3.2.
This hand  has an integral  motor,gearbox,  brake  and potentiometer.
Jaws are guided on steel rods  and driven by a single central  pinion
and double racks.

	3) To meet the requirements of section  3.3,  which specifies
an  accuracy and precision within  a working volume  much larger than
the defined  workspace of  our standard  manipulator(see  specs.   on
attachment 1),   the arm will  have to be made  with closer machining
tolerances.  The potentiometer elements on joints 1,2 and 3 will also
have to be changed to improve their linearity,and noise level to meet
the increased resolution  and accuracy requirements. Joints 4,5,6 and
the hand will keep our standard integral potentiometers.

	4) We strongly suggest  that the use  of optical encoders  be
considered instead of  potentiometers on joints  1,2, and 3  as these
devices  are inherently  highly linear,   can have  more than  12 bit
resolution, and interface directly to  the i/o buss rather than  thru
an a/d. Our standard manipulator is available with 13 bit incremental
encoders  on  the  first  3  joints  with  a  resulting  increase  in
resolution and accuracy as noted in our specification  sheet. We have
suggested  but  not   proposed  optical  encoders  only  because  the
solicitation requires that the sensor interface  to an a/d and it  is
not practical nor  realistic to consider  using a d/a to  get encoder
output  into a form suitable  for an a/d. A  third alternative is the
use of resolvers as joint position sensors.

	5) To  satify another  requirement of  section  3.3 that  the
manipulator follow an arbitrary straight line trajectory at any reach
and load  up to the maximums specified,  will require the addition of
forced air (fan) cooling of  the motors.  This is  because conditions
of maximum  torque and  large duty cycle  can be encountered  in this
mode; as in the case of a very long and slow motion at maximum load.  

	6) To insure  meeting the task  performance, overshoot,   and
stiffness specifications,   the  servo system  will be a  combination
hardware  and software  servo system.   All 6  joints will  have both
analog tachometer  and position  feedback.   At the  present time  we
suggest implementing  high frequency  velocity feedback  in hardware,
but position and low frequency velocity feedback thru the computer. A
completely  hardware  servo  system  is  also  proposed  to  simplify
installation,     checkout   and  the   acceptance  testing   of  the
manipulator,  as  this will  easily interface with  the existing  NBS
teach mode software.

	7)  Software  for  control of  a  manipulator  of  this  type
presently  exsits at the Stanford  University Artificial Intelligence
Laboratory (on  the ARPANET).   Current software  is for  use with  a
PDP-10 and PDP-6.  Both of these computers are 36 bit word,  floating
point processors.  Servo code is presently being written for use on a
PDP-11/45,  and is expected  to be in useable form before the  end of
this year.

	8) Per section 3.5,   joint 6 will be redesigned to give it a
maximum torque equal to  that of joint 5,   while maintaining a  gear
ratio which will  still allow it to  meet the speed requirement  of 8
radians/sec.  This will require a larger motor, stronger gearing, and
a larger housing.   It is observed  that the peak power  requirements
represented by  the specifications  imply that the  motor of  joint 6
should  have twice the power of  joint 5.  As  an alternative,  it is
possible to increase the strength of the brake in  the standard joint
6.   This could allow  the braked torque  of the standard  joint 6 to
equal the maximum torque of joint 5.

	9) Manual Control.   The  manipulator will be  an "Option  C"
type with  brakes on all  six joints,and the  hand.  All  joints will
have  either harmonic drive or  spur gear gearboxes  which will allow
them to be backdriven manually with the brakes off.  


	Several specifications  presented in  the RFP  have not  been
discussed above.  This is because  our standard arm meets these other
requirements with  little or no modification.  In any event it may be
taken  that  provisions  have  been  made   for  safely  accomodating
overloads  or full  scale command  errors and  meeting  the interface
connection requirements, etc.
			PRICES

Complete manipulator including ALL the requirements of the
solicitation.   - $37,500

Manipulator as above execpt without- Internal wiring specs(paragraph 1)
				     Min. velocity specs at full load.

				$27,500

Manipulator as in B above, execpt without
			- high strength joint 6, but with high strength
			 brake(paragraph 5).

				$24,500

These prices include the acceptance tests at NBS facilities per section
5.0 of the solicitation, all the 
specified documentation in section 4.0., and delivery within  150 days
of award of contract.