Newsgroups: comp.robotics
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From: arc@leland.Stanford.EDU (Andrew Richard Conway)
Subject: Re: 3-D Xwindows robotics program
Message-ID: <1993Feb8.225444.14111@leland.Stanford.EDU>
Sender: news@leland.Stanford.EDU (Mr News)
Organization: DSG, Stanford University, CA 94305, USA
References: <1993Feb8.160957.1@cajun>
Date: Mon, 8 Feb 93 22:54:44 GMT
Lines: 44

In article <1993Feb8.160957.1@cajun> daship@cajun writes:
>I'm thinking about writing a program that emulates robots of different
>configurations, and their mechanics.  You would be able to enter the
>number of joints, what type of joint each is, the length of connecting
>arms between joints, the initial angle of joints, etc.  I would probably
>implement a parameter table to do this.  Anyway, after entering this
>information, you could specify desired final angles and the program would
>show the movement of the robot in three dimensional graphics (hopefully in
>real-time wireframe).  I would like to write the program in C++ and X-windows.
>My question is this... are there currently any programs out there that I
>would be duplicating the effort of?  I would also be interested in knowing
>what you'all think would be a good platform for the development of this
>program (to be as portable as possible... I have access to Sun, HP, PC, and
>possibly DEC workstations).  I would appreciate any comments.
>
>Thanks in advance......
>
>-Dan-
>
>E-Mail:  DASHIP@CAJUN.MONSANTO.COM

Yes, a friend and I wrote a program that did all that (on Silicon
Graphics workstations). It took arbitary numbers & types of links, 
friction & gravity, and allowed you to control forces or torques/
acceleration/velocity/position for each joint, and graph any variables
you want. There was also a nice "cad" type system that let you
make a controler for the robot using Laplace-transformed operators.
The whole thing had a nice GUIshowing the robot itself, various
controls, including each joint, graphs of whatever you want,
and the controler schematic. Oh, and there was a very rudimentary
planner.

It was really nice to set up a 10 link pendulum, set all motor torques
to zero, and start it from an inverted position and watch it swing...

Now, it wasn't X, but rather the Silicon Graphics library routines
(which could do it real time). I believe that someone is working
on modifying it for X, but I'm not sure since we wrote it in a week
(deadlines, you know) for an undergrad engineering project, and
then I pretty much forgot about it. I'll ask my friend what has happend
with it.

Andrew Conway.

