Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!agate!howland.reston.ans.net!cs.utexas.edu!utnut!torn!govonca!knights
From: knights@govonca.gov.on.ca (Shawn Knight)
Subject: Re: Robotics and VR (how I spend Christmas Vacation)
Message-ID: <1994Feb26.170319.9521@govonca.gov.on.ca>
Organization: Government of Ontario
References: <2kkgom$amt@unicorn.ccc.nottingham.ac.uk>
Date: Sat, 26 Feb 1994 17:03:19 GMT
Lines: 103

In <2kkgom$amt@unicorn.ccc.nottingham.ac.uk> pre@pine.nott.ac.uk (Phillip Edwards) writes:

>I am interested in finding out about any work being
>done which combines robotics with virtual reality.
>I am particularly interested in programming applications
>but would also be interested in all other such activities.

>I will be grateful for any information on this.

>Phill

During the Christmas season I created a telepresence robot to be run from my
BBS (The Toronto Virtual Reality Special Interest Group BBS).  Just to
summerize quickly what happened and how it was done:
 
Before starting, the following was manditory:
 
   . Able to be controlled from a remote location
   . Able to be controlled by anyone with a PC and a 9600 baud modem
   . Must be low cost (I'm broke)
   . Must be completed over a time span of 2 weeks (christmas vactation)
 
What was used:
 
   . Modified Omni-Bot from Tomy
   . RC from Omni-Bot hacked to plug into standard PC
   . Video camera mounted on top of omni bot
   . Low cost, low grade compartor video frame grabber plugged into PC
   . Custom written video compression routines on PC server
   . Custom written video decompression routines on PC client
 
Software (techy):
 
   . Two custom 'C' software applications were used, written by me:
       . PC server, running at robot's location
          . controlled robot
          . compressed video frames and buffered over a modem
          . recieved 'tele-typed' messages from remote
       . PC client, running at client's location
          . received direction info from user (arrow keys on keyboard),
            relayed to server
          . received compressed video info from modem, decompressed,
            displayed on VGA screen.
          . allowed two way 'tele-type' chat mode encoded with video
            frames to talk from and from server operator
   . Video compression routines allowed for lossy and non-lossy modes,
     depending on user's preference of speed over quality
   . Video was displayed in a window on remote's vga screen, size of
     120x60 by 16 grey levels, currently working routines to double
     this resolution, but not integrated into robot software as yet
   . Frame rate was (depended a lot on v.32 compression and modem
     optimization on remote's modem):
        .  .5 to 2 frames per second non-lossy mode
        .  4 to 15 frames per second lossy mode
 
What the user did:
 
  . Client user called my BBS number and downloaded the client program
  . Client shelled from communications software, or hung up and called
    back to, execute the downloaded client program
  . In dumb terminal mode, user executed a 'door' on BBS to start the
    server program
  . A video image is displayed in the middle of clients screen of what
    the robot is looking at (about 2 feet from the floor)
  . The user was able to use the arrow keys on their keyboard to move
    the robot around (about 3 feet per second), rotation of 5 to 10 degrees
    per keypress.
  . The user was able to select a slow good quality image (I called
    non-lossy) or a quick updating low quality image (I called lossy).
    While in lossy mode, the user was able to press <CTRL> D to demand
    a non-lossy frame to refresh the screen with a good image, returning
    back to the lossy mode.
 
Results:
 
(bad:)
  . Some users complained that:
     . the image was too small (working on the double sized image now)
     . robot was not responsive enough and the user can get lost
       when key pressed, and the lossy routines get really lossy
       quickly (this is true, as rotation amount is unpredicatable
       if too much image changes per frame).
 
(good):
 
  . The project was completed in time
  . approx 25 people used the robot over the next 3 days
  . The project must have been successful, as the users who called used
    in excess of 45 minutes per call (it was running in my basement,
    not much to look at for 45 minutes!  Although my kids did make
    two feet high art works for the callers to look at)
  . Several first time callers called back the next day to use it again.
  . I found something to do over my Christmas Vacation
 
More info:
 
  . The robot is still alive, although I do not have much time now
    to man it to use
  . My BBS is the Toronto Virtual Reality Special Interest Group BBS
    in Toronto, Ontario, Canada  (416) 631-6625  24 hrs  16.8K HST/V.42
  . My email account is knights@gov.on.ca
  . Contact me if you have any questions, suggestions, comments
 
