cam@aipna.ed.ac.uk (Chris Malcolm) (01/30/91)
There have been a number of postings asking for a small cheap robot. Write to: John R. Allright Hasfield Systems Ltd., The Old Rectory Stables, Hasfield, Gloucester GL19 4LG UK Tel: +44 (0)45278 754 Fax: +44 (0)45278 858 - for information on the Armdroid HS1B and other robots they make. The Armdroid is the cheapest. It is a 5-axis stepper motor robot, with the joints driven by toothed belts, and costs in the approx region of 700 pounds. It is an improved version of the old Kevlar string-and-pulley Armdroid. It is driven off an 8-bit // port (e.g printer) of any PC. Reach about 480mm, load about .25kg, resolution and repeatability between 0.5 and 3mm depending on attitude. Optional extras are force sensing in the gripper and optical "home" encoders for semi-automatic calibration, but if you have workshops it's quite easy to add this kind of stuff yourself. Comes with driving software for most popular kinds of microcomputer. For two years we used the early version of this robot for teaching. We gave it up only because the students were too rough with it, and technicians had to keep adjusting the strings. Apart from that I thought it an excellent teaching robot. One of the good features of the stepper motor drive is that it is quite easy for a _good_ student in a few months to implement a complete controller from scratch. Only the motor pulse co-ordination loops need to be in assembly code (6 motors running smoothly at up to 400Hz), the rest can be in any high level language you like. We recently had our Armdroids upgraded to the new toothed belt drive, which should remove this problem, but they have not yet been subjected to the ultimate test of real students. Not unimportant for teaching use it that it is very easy to convince the authorities that this robot is too slow and weak to be capable of damaging a student. Even if the student dropped it on his foot it probably wouldn't do any damage. This is an important consideration when Universities are held responsible for the health and safety of their students, and some students are quite capable of injuring themselves with such simple equipment as pencils. -- Chris Malcolm cam@uk.ac.ed.aipna +44 (0)31 667 1011 x2550 Department of Artificial Intelligence, Edinburgh University 5 Forrest Hill, Edinburgh, EH1 2QL, UK DoD #205
yamauchi@cs.rochester.edu (Brian Yamauchi) (01/31/91)
In article <3926@aipna.ed.ac.uk> cam@aipna.ed.ac.uk (Chris Malcolm) writes:
Not unimportant for teaching use it that it is very easy to convince the
authorities that this robot is too slow and weak to be capable of
damaging a student. Even if the student dropped it on his foot it
probably wouldn't do any damage. This is an important consideration when
Universities are held responsible for the health and safety of their
students, and some students are quite capable of injuring themselves
with such simple equipment as pencils.
They ought to try working next to a visually-reactive Puma 761 running
at top speed :-).
--
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Brian Yamauchi University of Rochester
yamauchi@cs.rochester.edu Department of Computer Science
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