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Subject: 
Re: Walkers
Newsgroups: 
lugnet.robotics
Date: 
Fri, 9 Feb 2001 23:37:39 GMT
Original-From: 
Steve Baker <sjbaker1@{avoidspam}airmail.net>
Reply-To: 
sjbaker1@airmail.NOMORESPAMnet
Viewed: 
715 times
  
Harley Myler wrote:

What you really want to ask here is "Has anyone built a 2-legged walker with balance?".
I would say it is unlikely that one has been built, but certainly not impossible.
For a balancing mechanism you need position sensing, which could be done with a
rotary (distance) counter and a pendulum.

I tried that in my attempts to build a two wheeled robot (as in a bicycle)...but
the problem with rotation sensors (as has been discussed *extensively* before)
is that it drops or gains counts sometimes when it's being rotated slowly.

That means that you really have gear up the pendulum's output in order to
spin the rotation sensor quickly - and that gearing slows the swing of the
pendulum to the point of uselessness...unless it's VERY heavy.

I had better luck with a two-coloured pendulum and a light sensor...but
there were many other problems - and I never did get it to work.

Incidentally, the way most bipeds walk is by leaning forwards so their
Center of gravity is ahead of their feet - and then sticking out a foot
to prevent themselves from falling.  It follows that balancing the robot
may not be the best strategy here.


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Message has 1 Reply:
  Re: Walkers
 
(...) My post was to clarify the walker question, the suggestion of using the position sensor was just that. (...) The walker problem is not trivial, as you've discovered. (...) That is a correct observation, but no one wants a walker that can't (...) (24 years ago, 10-Feb-01, to lugnet.robotics)

Message is in Reply To:
  Re: Walkers
 
(...) What you really want to ask here is "Has anyone built a 2-legged walker with balance?". I would say it is unlikely that one has been built, but certainly not impossible. For a balancing mechanism you need position sensing, which could be done (...) (24 years ago, 9-Feb-01, to lugnet.robotics)

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