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Subject: 
Re: Wireless Robots
Newsgroups: 
lugnet.robotics
Date: 
Sun, 21 Nov 1999 22:28:04 GMT
Original-From: 
Pete Sevcik <sevcik@flashNOSPAM.net>
Viewed: 
2068 times
  
Matt,

I have built a lego robot controlled by a PC, using an IR link to communicate
commands.  It used the same IR technology as Mindstorms, but had an
omni-directional IR link on the robot.  The problem is link speed.  For reliable
communication, you need an error recovery protocol on the link.  I designed a
lightweight protocol, which worked well but added about 5 bytes of packet
overhead.  At 1200 baud, it takes too long to get data to the PC, and get the
response back to the robot.  e.g  the sensor detects a wall, but by the time you
get that info to the PC, and get back a command to turn, you have already hit
the wall.  IRDA technology is faster, but the distance is limited to 3 feet.
Radio links would be fine, but the low cost links are limited to about 1200
baud.

I was trying to do all the processing in the PC.  The technique might work if
you found a way to split the work.  Do  tasks that require a quick reaction time
within the robot.  Send the slower, more difficult tasks, back to the PC.  If
you use a video camera, send the video data as analog, directly to the PC.

    - pete.



Matt Ramadanovic wrote:

> Has anyone tried to use wireless networking to control a legorobot?
> IP programming in VB is easy and I was thinking of making a robot
> which uses the RCX as its medulla and a stripped down laptop with
> a PCMCIA Ethernet adapter as the cerebrum. The idea is to have a
> digital camera mounted on the thing sending back video along with
> passing instructions to the RCX (most of the bandwidth would be unused
> if it was just sending instructions). The command console would sit on
> a regular PC and would host an app that talks to the "brain" of the robot.
> I don't have my kit yet so I have not tried programming a brick - though
> have
> seen the .ocx. I was thinking of creating functions in assembly and
> compiling
> a .dll in Delphi that VB programs could make calls to add functionality. Has
> anybody tried this approach yet? Once I get the hardware, anyone want to
> collaborate on a .dll?
> 
> Matt


--
Pete Sevcik     sevcik@flash.net
Techno-stuff Robotics
http://www.flash.net/~sevcik/
Robotics for FUN !



Message has 2 Replies:
  Re: Wireless Robots
 
Hi Pete, I have been reading about AI concepts a lot lately (and my partner here at work has his doctorate in AI), so I have some thoughts about your comments below: (...) time you (...) hit (...) [snip] (...) if (...) The current path in robotics (...) (27 years ago, 22-Nov-99, to lugnet.robotics)
  Re: Wireless Robots
 
(...) reliable (...) you (...) Would you consider making the RIS perform the check or just sending a verbatim copy of what it gets to the sender (two way radio) and making the PC check that the information was sent OK. I know that a bad packet from (...) (27 years ago, 22-Nov-99, to lugnet.robotics)

Message is in Reply To:
  Wireless Robots
 
Has anyone tried to use wireless networking to control a legorobot? IP programming in VB is easy and I was thinking of making a robot which uses the RCX as its medulla and a stripped down laptop with a PCMCIA Ethernet adapter as the cerebrum. The (...) (27 years ago, 20-Nov-99, to lugnet.robotics)

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