[chbot] Balancing robots

Tue Oct 21 00:12:36 BST 2008

Not to late..... Only 7pm Here in Montreal Canada ;-)

dsPICs... think it came down to price... a handful of dsPICs in volume
can beat a single high end DSP for price... and possibly Steve Sangi
being friends with Dean Kamen may have something to do with it.

Well better be on my way to a NXP sponsored evening activity (For work).

P.S. You can still vote for my entry in the myPIC32 competition.. 30
hours of voting time to go.... I believe they have fixed the
registration process for .nz domains... but check your spam box if you
don't get the password email.

Carbcounter+ by mimemike (AKA Mike Pearce)
http://www.mypic32.com/web/guest/contestantsprofiles?profileID=13642

Thanks,

Mike

On Mon, Oct 20, 2008 at 4:44 PM, John Stowers <john.stowers at gmail.com> wrote:
>
>
> On Tue, Oct 21, 2008 at 12:41 AM, John Stowers <john.stowers at gmail.com>
> wrote:
>>
>> On Tue, Oct 21, 2008 at 12:27 AM, Michael Pearce <mike at kiwacan.co.nz>
>> wrote:
>>>
>>> > This is a level of stability and control not achievable with simplistic
>>> > PID
>>> > or Fuzzy controllers.
>>>
>>> Actually the Segway used a good number of dsPICs to do it all.... so
>>> not as much processing power as you may have presumed.... (Note: dsPIC
>>> is _NOT_ a dsp- it is a 16 bit digital signal Controller up to 40MIPS)
>>
>> I wasn't referring to simplistic in the computational complexity sense, I
>> was referring to it in reference to the theoretical foundations of the
>> approaches.
>
> wow, too many references there. Too late at night.
>
>>
>>
>>> Was definitely in the 2007 version.... may be different now.
>>
>> Cool, thats actually quite interesting to know. I wonder what drove their
>> decisions to go with the dsPICs.
>>
>> John
>>
>>>
>>>
>>> Mike
>>>
>>> On Mon, Oct 20, 2008 at 1:11 AM, John Stowers <john.stowers at gmail.com>
>>> wrote:
>>> > This was created by Dean Kamen, i.e. Mr Segway. I expect it uses some
>>> > of the
>>> > control technology inherited from that project.
>>> >
>>> > Presumably, like the segway, it uses one or multiple voting, optimal
>>> > state
>>> > space controller/s.
>>> >
>>> > This is a level of stability and control not achievable with simplistic
>>> > PID
>>> > or Fuzzy controllers.
>>> >
>>> > John
>>> >
>>> > On Mon, Oct 20, 2008 at 1:34 AM, Charles Manning <cdhmanning at gmail.com>
>>> > wrote:
>>> >>
>>> >> Pretty neat.
>>> >>
>>> >> I think there are a few things which really help keep this thing
>>> >> stable:
>>> >>
>>> >> 1) Moment of inertia.  A heavy item placed relatively far from the
>>> >> wheels
>>> >> is far easier to balance than a light one. That's part of the reason
>>> >> Hanno
>>> >> has the batteries on the top of the pole of his robot . Having an
>>> >> object the
>>> >> size of a human helps.
>>> >> 2) Relatively unlimited budget. Hanno is trying to make a cheap
>>> >> consumer
>>> >> item while these flash wheelchairs cost many thousands.
>>> >>
>>> >>
>>> >> Some horizontal reference, typically accelerometers because they are
>>> >> small, cheap and reliable, need to be part of any gyro-based solution
>>> >> because gyro sensors give you the rate of rotation and you need a
>>> >> horizontal
>>> >> reference to cancel out any offset (normally done in a Kalman filter).
>>> >> If
>>> >> you don't cancel out this offset then the machine would seem to be
>>> >> slowly
>>> >> rolling.
>>> >>
>>> >> -- Charles
>>> >>
>>> >>
>>> >>
>>> >> On Sun, Oct 19, 2008 at 5:23 PM, QtuTrains <Howard at qtutrains.com>
>>> >> wrote:
>>> >>>
>>> >>> If you think Hanno's balancing robot is interesting just take a look
>>> >>> at this:
>>> >>>
>>> >>> http://www.powerchair-review.fsnet.co.uk/ibot-4000-transporter-full-
>>> >>> review.htm
>>> >>>
>>> >>> The manufacture's site is http://www.ibotnow.com/ but I couldn't get
>>> >>> it to respond when I looked.
>>> >>>
>>> >>> Its a wheelchair that can rise onto two wheels and balance with a
>>> >>> person sat in it.
>>> >>>
>>> >>> It can also climb stairs!
>>> >>>
>>> >>> We saw one today at the Canterbury museum (not an exhibit!) and the
>>> >>> owner said it was the only one in New Zealand.
>>> >>>
>>> >>> It looked amazingly stable - much less oscillation to keep upright
>>> >>> than Hanno has achieved thus far. Naturally it uses gyroscopes for
>>> >>> balance, perhaps accelerometers too but the owner wasn't too much
>>> >>> into the technical details.
>>> >>>
>>> >>> The point of balancing is improved manoeuvrability and visibility
>>> >>> through increased height which was obviously useful in the museum.
>>> >>>
>>> >>> Howard
>>> >>>
>>> >>> _______________________________________________
>>> >>> Chchrobotics mailing list
>>> >>> Chchrobotics at lists.linuxnut.co.nz
>>> >>> http://lists.ourshack.com/mailman/listinfo/chchrobotics
>>> >>
>>> >>
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>>> >>
>>> >
>>> >
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>>> >
>>> >
>>>
>>>
>>>
>>> --
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>>
>
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