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Subject: 
Re: Seeking Strategies on Humanoid Robots/Walkers
Newsgroups: 
lugnet.robotics
Date: 
Thu, 21 Jan 1999 05:52:36 GMT
Viewed: 
4656 times
  
Jasper Janssen wrote in message <36a3ca48.45364286@lugnet.com>...
> On Sat, 2 Jan 1999 04:19:43 GMT, lego-robotics@crynwr.com (Andrew
> Phelps) wrote:
> 
> > Well, that is the million dollar question, so to speak :)
> > posted.  Am I to assume then that no one on this list has done this ?  Let
> 
> I seem to recall that noone has succesfully solved the problem of
> artificial biped locomotion even in traditional robotics, let alone


    This problem has been solved with both fuzzy logic and neural
    network control systems.  I believe that a traditional control
    system approach to this problem has yielded poor results.

    The sensors used in this type of robot are typically semiconductor
    based accelerometers and gyroscopes.

> within the constraints of LEGO. Basically, what you need is a system

    No, I don't think anyone will be solving this problem using
    Mindstorms.  There is a whole list of limitations:

    - slow processor
    - wrong processor architecture
    - wrong software tools
    - inadequate sensors
    - inadequate actuators

    There are robots today that have actuators that simulate muscles,
    and I'm not talking about pulleys and micromotors, I am talking
    about technology out there on the cutting edge.

    I wish Lego had news and information about this kind of stuff
    on the Mindstorms site, instead of the lame-o stuff they usually
    show for excruciatingly long times.


> that can sense very delicate shifts in balance, and shift its point of
> gravity to account for that. This is _difficult_, especially if you
> want to have your robot do anything else. And that's just standing
> still. Of course, you could make him/her be very flatfooted (if you're
> thinking about a model of say 50 studs high, think the 20*40
> baseplates as feet :) ), and have the robot stand on one of the feet,
> while moving the other forward, then shifting the COG (center of
> Gravity) to above the other foot.., etc.
> 
> 
> maybe you could have a foot profile such as:
> 
> 1111111111111
> 1
> 1
> 1  2222222222222
> 1              2
> 1              2
> 1111111111111  2
> 1              2
> 1              2
> 1  2222222222222
> 1
> 1
> 1111111111111
> 
> 
> where 1 is one foot, and 2 the other. But that doesn't lookmuch like a
> human foot anymore, and dancing would also be difficult.
> 
> If you want, say, a leg to have motion in the groin, knee, and ankle
> areas, you're already looking at 6 motors. Or rather, Servos or
> Pneumatics/Hydraulics: Lego motors aren't nearly accurate enoughfor
> most things.
> 
> Well, back to RCX reality: Unless you have _plenty_ of cash and can
> buy a dozen RCXs and solder the interfaces between em (it'd prolly be
> easier to just take a real microcontroller, btw), you're gonna have to
> simplify. My solution, tentatively theoretical: use the extra "stalks"
> as in the picture above on the feet to help it keep it's balance, have
> the ankle fixed, and the knee and groin joints set at the same angle,
> in reverse:
> 
> O
> /
>        /
>              /
>             /
>            o
>            |
>            |
>            |
>        ---------
> 
> 
> Then make something with a large gear so it runs in a somehwat
> circular motion, with the leg lifting off of the ground at the back of
> the cycle, then go back to the front, then put foot down, move to
> back, etc. I think you coul prolly gear the l/r leg to work on one
> gear train, with one, possibly two motors to drive it. I haven't
> solved left right yet, have I? Hmm... need to think about that.
> 
> 
> Thanks for giving me such an interesting idea to think about :)
> 
> Jasper
> 
> 



Message has 1 Reply:
  Re: Seeking Strategies on Humanoid Robots/Walkers
 
Patrick Gili wrote in message ... (...) Actually, they can be built with *relatively* simple, active-feedback systems for the balance and control. Simple legged robots (one leg is actually easier than two to control) have been around since ~1980. (...) (28 years ago, 21-Jan-99, to lugnet.robotics)

Message is in Reply To:
  Re: Seeking Strategies on Humanoid Robots/Walkers  [DAT]
 
(...) I seem to recall that noone has succesfully solved the problem of artificial biped locomotion even in traditional robotics, let alone within the constraints of LEGO. Basically, what you need is a system that can sense very delicate shifts in (...) (28 years ago, 19-Jan-99, to lugnet.robotics)

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