{"id":57,"date":"2012-04-28T21:30:49","date_gmt":"2012-04-28T21:30:49","guid":{"rendered":"http:\/\/projecthexapod.com\/blog\/?p=57"},"modified":"2012-04-28T21:39:01","modified_gmt":"2012-04-28T21:39:01","slug":"beware-the-barge","status":"publish","type":"post","link":"http:\/\/projecthexapod.com\/blog\/2012\/04\/beware-the-barge\/","title":{"rendered":"Beware the Barge"},"content":{"rendered":"<p>I built a model of the leg cart\/leg test stand in our simulation environment.\u00a0 Leg dimensions, masses, ranges of motion and actuator force limits are all in the model.<\/p>\n<p>On the meatspace implementation the inputs to the system will be valve commands, which roughly correlate to flow rates.\u00a0 In an attempt to model this, we present actuator linear rates as the inputs to the model.<\/p>\n<p>This week we assigned the controls team the task of controlling the cart and making it row itself along in a straight, controlled line.\u00a0 We&#8217;ve got groups working on joint level control, forward kinematics, inverse kinematics, trajectory generation and the nebulous &#8220;high level&#8221;.\u00a0 As a starting point I put together a little demo with the leg cart rowing itself along very poorly:<\/p>\n<p>&nbsp;<br \/>\n<object style=\"height: 390px; width: 640px;\" width=\"640\" height=\"360\" classid=\"clsid:d27cdb6e-ae6d-11cf-96b8-444553540000\" codebase=\"http:\/\/download.macromedia.com\/pub\/shockwave\/cabs\/flash\/swflash.cab#version=6,0,40,0\"><param name=\"allowFullScreen\" value=\"true\" \/><param name=\"allowScriptAccess\" value=\"always\" \/><param name=\"src\" value=\"http:\/\/www.youtube.com\/v\/EeRwmIOdcq8?version=3&amp;feature=player_detailpage\" \/><param name=\"allowfullscreen\" value=\"true\" \/><param name=\"allowscriptaccess\" value=\"always\" \/><embed style=\"height: 390px; width: 640px;\" width=\"640\" height=\"360\" type=\"application\/x-shockwave-flash\" src=\"http:\/\/www.youtube.com\/v\/EeRwmIOdcq8?version=3&amp;feature=player_detailpage\" allowFullScreen=\"true\" allowScriptAccess=\"always\" allowfullscreen=\"true\" allowscriptaccess=\"always\" \/><\/object><\/p>\n<p>For reference, the cart weighs about 600 pounds and the pins weigh about 200 pounds and are 6 feet tall. When this thing exists in real life, we will have to be very careful&#8230;\u00a0 More videos next week when the student solution starts coming together!<\/p>\n<p>~James<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I built a model of the leg cart\/leg test stand in our simulation environment.\u00a0 Leg dimensions, masses, ranges of motion and actuator force limits are all in the model. On the meatspace implementation the inputs to the system will be valve commands, which roughly correlate to flow rates.\u00a0 In an attempt to model this, we &hellip; <a href=\"http:\/\/projecthexapod.com\/blog\/2012\/04\/beware-the-barge\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Beware the Barge<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-57","post","type-post","status-publish","format-standard","hentry","category-simulation"],"_links":{"self":[{"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/posts\/57","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/comments?post=57"}],"version-history":[{"count":10,"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/posts\/57\/revisions"}],"predecessor-version":[{"id":68,"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/posts\/57\/revisions\/68"}],"wp:attachment":[{"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/media?parent=57"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/categories?post=57"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/projecthexapod.com\/blog\/wp-json\/wp\/v2\/tags?post=57"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}