<div dir="ltr"><br><br><div class="gmail_quote">On Tue, Oct 21, 2008 at 12:41 AM, John Stowers <span dir="ltr"><<a href="mailto:john.stowers@gmail.com">john.stowers@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div dir="ltr"><br><div class="gmail_quote"><div class="Ih2E3d">On Tue, Oct 21, 2008 at 12:27 AM, Michael Pearce <span dir="ltr"><<a href="mailto:mike@kiwacan.co.nz" target="_blank">mike@kiwacan.co.nz</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>> This is a level of stability and control not achievable with simplistic PID<br>
> or Fuzzy controllers.<br>
<br>
</div>Actually the Segway used a good number of dsPICs to do it all.... so<br>
not as much processing power as you may have presumed.... (Note: dsPIC<br>
is _NOT_ a dsp- it is a 16 bit digital signal Controller up to 40MIPS)</blockquote></div><div><br>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.</div>
</div></div></blockquote><div><br>wow, too many references there. Too late at night.<br> <br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div dir="ltr"><div class="gmail_quote"><div><br>
<br></div><div class="Ih2E3d"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Was definitely in the 2007 version.... may be different now.</blockquote></div><div><br>Cool, thats actually quite interesting to know. I wonder what drove their decisions to go with the dsPICs.<br><font color="#888888"><br>
John<br> <br></font></div><div><div></div><div class="Wj3C7c"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
<br>
Mike<br>
<div><div></div><div><br>
On Mon, Oct 20, 2008 at 1:11 AM, John Stowers <<a href="mailto:john.stowers@gmail.com" target="_blank">john.stowers@gmail.com</a>> wrote:<br>
> This was created by Dean Kamen, i.e. Mr Segway. I expect it uses some of the<br>
> control technology inherited from that project.<br>
><br>
> Presumably, like the segway, it uses one or multiple voting, optimal state<br>
> space controller/s.<br>
><br>
> This is a level of stability and control not achievable with simplistic PID<br>
> or Fuzzy controllers.<br>
><br>
> John<br>
><br>
> On Mon, Oct 20, 2008 at 1:34 AM, Charles Manning <<a href="mailto:cdhmanning@gmail.com" target="_blank">cdhmanning@gmail.com</a>><br>
> wrote:<br>
>><br>
>> Pretty neat.<br>
>><br>
>> I think there are a few things which really help keep this thing stable:<br>
>><br>
>> 1) Moment of inertia. A heavy item placed relatively far from the wheels<br>
>> is far easier to balance than a light one. That's part of the reason Hanno<br>
>> has the batteries on the top of the pole of his robot . Having an object the<br>
>> size of a human helps.<br>
>> 2) Relatively unlimited budget. Hanno is trying to make a cheap consumer<br>
>> item while these flash wheelchairs cost many thousands.<br>
>><br>
>><br>
>> Some horizontal reference, typically accelerometers because they are<br>
>> small, cheap and reliable, need to be part of any gyro-based solution<br>
>> because gyro sensors give you the rate of rotation and you need a horizontal<br>
>> reference to cancel out any offset (normally done in a Kalman filter). If<br>
>> you don't cancel out this offset then the machine would seem to be slowly<br>
>> rolling.<br>
>><br>
>> -- Charles<br>
>><br>
>><br>
>><br>
>> On Sun, Oct 19, 2008 at 5:23 PM, QtuTrains <<a href="mailto:Howard@qtutrains.com" target="_blank">Howard@qtutrains.com</a>> wrote:<br>
>>><br>
>>> If you think Hanno's balancing robot is interesting just take a look<br>
>>> at this:<br>
>>><br>
>>> <a href="http://www.powerchair-review.fsnet.co.uk/ibot-4000-transporter-full-" target="_blank">http://www.powerchair-review.fsnet.co.uk/ibot-4000-transporter-full-</a><br>
>>> review.htm<br>
>>><br>
>>> The manufacture's site is <a href="http://www.ibotnow.com/" target="_blank">http://www.ibotnow.com/</a> but I couldn't get<br>
>>> it to respond when I looked.<br>
>>><br>
>>> Its a wheelchair that can rise onto two wheels and balance with a<br>
>>> person sat in it.<br>
>>><br>
>>> It can also climb stairs!<br>
>>><br>
>>> We saw one today at the Canterbury museum (not an exhibit!) and the<br>
>>> owner said it was the only one in New Zealand.<br>
>>><br>
>>> It looked amazingly stable - much less oscillation to keep upright<br>
>>> than Hanno has achieved thus far. Naturally it uses gyroscopes for<br>
>>> balance, perhaps accelerometers too but the owner wasn't too much<br>
>>> into the technical details.<br>
>>><br>
>>> The point of balancing is improved manoeuvrability and visibility<br>
>>> through increased height which was obviously useful in the museum.<br>
>>><br>
>>> Howard<br>
>>><br>
>>> _______________________________________________<br>
>>> Chchrobotics mailing list<br>
>>> <a href="mailto:Chchrobotics@lists.linuxnut.co.nz" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>
>>> <a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>
>><br>
>><br>
>> _______________________________________________<br>
>> Chchrobotics mailing list<br>
>> <a href="mailto:Chchrobotics@lists.linuxnut.co.nz" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>
>> <a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>
>><br>
><br>
><br>
> _______________________________________________<br>
> Chchrobotics mailing list<br>
> <a href="mailto:Chchrobotics@lists.linuxnut.co.nz" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>
> <a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>
><br>
><br>
<br>
<br>
<br>
</div></div><font color="#888888">--<br>
Kiwacan<br>
<a href="http://www.kiwacan.co.nz" target="_blank">http://www.kiwacan.co.nz</a><br>
<a href="http://www.kiwacandirect.com" target="_blank">http://www.kiwacandirect.com</a><br>
USA: 1-800-490-2091<br>
NZL: +64-3-669-0077<br>
</font><div><div></div><div><br>
_______________________________________________<br>
Chchrobotics mailing list<br>
<a href="mailto:Chchrobotics@lists.linuxnut.co.nz" target="_blank">Chchrobotics@lists.linuxnut.co.nz</a><br>
<a href="http://lists.ourshack.com/mailman/listinfo/chchrobotics" target="_blank">http://lists.ourshack.com/mailman/listinfo/chchrobotics</a><br>
</div></div></blockquote></div></div></div><br></div>
</blockquote></div><br></div>