The whisking robot SCRATCHbot.

<p>A. Photographs of the mobile whiskered robot SCRATCHbot exploring the environment using its bilateral array of active artificial whiskers. It has been used to test hypothetical models of whisker array based object detection (in this case a sphere) and action selection mechanisms. B. SCRATCHbot in a ‘head-fixed’ preparation on a workbench. Band-pass filtered white noise and periodic whisking patterns were used to drive one of the whisker column actuators that generated the whisker response data sets described here. Upper panel from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044560#pone-0044560-g003" target="_blank">Fig 3</a> of ref <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044560#pone.0044560-Anderson1" target="_blank">[31]</a>. C. Top: Front view of robot head, showing two columns of whiskers. There are three rows of whiskers on each side of the head, separated in the frontal plane by 30 deg. Deflections of the whisker shafts caused by reafferent (self-motion) and exafferent (contact) stimuli are measured at the base using IC tri-axis Hall effect sensors. Bottom: Top-down view of robot head. Six columns of whiskers are actuated independently by DC motors under Proportional, Integral, Derivative (PID) control through a maximum 120 deg. of rotation. The lengths of the whiskers decrease from front to back of the head (100–200 mm). From <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044560#pone-0044560-g004" target="_blank">Fig 4</a> of ref <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044560#pone.0044560-Anderson1" target="_blank">[31]</a>.