<p>As far as I know, the cylindrical robot type is one of the rarest nowadays. However, there are areas where they could still be useful. Also, they are always mentioned when stationary robot types are discussed, so I'll try to give you some insight on this topic.</p>
<p><img src="http://www.allonrobots.com/image-files/xrob_cyl.jpg.pagespeed.ic.UBN7f4exjt.jpg" alt="" width="350" height="259" /></p>
<p>http://www.allonrobots.com/cylindrical-robot.html</p>