{"id":12253,"date":"2021-09-04T11:56:24","date_gmt":"2021-09-04T15:56:24","guid":{"rendered":"https:\/\/www.purdue.edu\/freeform\/me274\/?page_id=12253"},"modified":"2026-02-06T14:57:45","modified_gmt":"2026-02-06T19:57:45","slug":"mrfs-views-from-different-reference-frames","status":"publish","type":"page","link":"https:\/\/www.purdue.edu\/freeform\/me274\/course-material\/animations\/mrfs-views-from-different-reference-frames\/","title":{"rendered":"MRF’s: views from different reference frames"},"content":{"rendered":"

Rolling without slipping<\/strong><\/em><\/p>\n

The observed motion of a point depends on the motion of the observer. Consider point P on the robotic arm shown below. Three GIFs are shown below the provide the view of the motion of point P as seen by three observers: i) an observer on fixed ground; ii) an observer attached to link OA; and, iii) an observer attached to link AP.<\/p>\n

Stationary observer
\n<\/strong><\/em>Here, the observed path of P is complicated. The observed motion includes the rotation of both links OA and AP.<\/p>\n

<\/p>\n

 <\/p>\n

Observer on link OA
\n<\/strong><\/em>Here, the observer is aware of only the rotation of AP about point A. Therefore, the observed path of P is a circle centered on A.
\n<\/strong><\/em><\/p>\n

<\/p>\n

 <\/p>\n

Observer on link AP
\n<\/strong><\/em>With the observer on the same rigid body at P, the observer is unaware that point P actually moves. Therefore, the observer sees a stationary point P. The observer also sees link OA rotating in the clockwise sense, when, in fact, it is rotating in the counter-clockwise sense.
\n<\/strong><\/em><\/p>\n

<\/p>\n

 <\/p>\n

Question<\/strong><\/em>: Which observer do you think would be most useful in calculating the velocity and acceleration of point P?<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Rolling without slipping The observed motion of a point depends on the motion of the observer. Consider point P on the robotic arm shown below. Three GIFs are shown below the provide the view of the motion of point P as seen by three observers: i) an observer on fixed ground; ii) an observer attached … Continue reading MRF’s: views from different reference frames<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":10,"featured_media":0,"parent":14,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-12253","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/pages\/12253","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/comments?post=12253"}],"version-history":[{"count":7,"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/pages\/12253\/revisions"}],"predecessor-version":[{"id":23925,"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/pages\/12253\/revisions\/23925"}],"up":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/pages\/14"}],"wp:attachment":[{"href":"https:\/\/www.purdue.edu\/freeform\/me274\/wp-json\/wp\/v2\/media?parent=12253"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}