{"id":90,"date":"2022-12-05T02:09:42","date_gmt":"2022-12-05T02:09:42","guid":{"rendered":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/?page_id=90"},"modified":"2023-04-16T03:10:42","modified_gmt":"2023-04-16T03:10:42","slug":"apriltags","status":"publish","type":"page","link":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/apriltags\/","title":{"rendered":"AprilTags"},"content":{"rendered":"\n<p>AprilTags are a visual fiducial system used in robotics and for camera calibrations. This system is based on a near-optimal robust lexicographic coding system. Provided this, the changes in lighting conditions and modes of viewpoint have little to no effect on the design and coding system. Conceptually speaking, AprilTags can be compared to QR codes as once they are scanned, hidden data is revealed. These tags are a type of two-dimensional bar code, but what results in the large separation between this system and other visual fiducial systems is the design. AprilTags have been created for the encoding of smaller data payloads that range between four and twelve bits of data. The main purpose of this is to allow for longer ranges to be detected and for the increase of robustness. Higher localization accuracy is also seen through the computation of the exact 3D position of each AprilTag with respect to the camera.<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"530\" height=\"358\" data-id=\"93\" src=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.07.33-PM.png\" alt=\"\" class=\"wp-image-93\" srcset=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.07.33-PM.png 530w, https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.07.33-PM-300x203.png 300w\" sizes=\"auto, (max-width: 530px) 100vw, 530px\" \/><figcaption class=\"wp-element-caption\">Figure 1.  Tag Families<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<p class=\"has-text-align-center\"><\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"376\" height=\"235\" data-id=\"96\" src=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.05.46-PM-edited.png\" alt=\"\" class=\"wp-image-96\" srcset=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.05.46-PM-edited.png 376w, https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.05.46-PM-edited-300x188.png 300w\" sizes=\"auto, (max-width: 376px) 100vw, 376px\" \/><figcaption class=\"wp-element-caption\">Figure 2. Live Feed &#8211; 36h11 Tag Detection<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-3 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"590\" height=\"210\" data-id=\"95\" src=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.05.55-PM.png\" alt=\"\" class=\"wp-image-95\" srcset=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.05.55-PM.png 590w, https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2022\/12\/Screen-Shot-2022-12-04-at-9.05.55-PM-300x107.png 300w\" sizes=\"auto, (max-width: 590px) 100vw, 590px\" \/><figcaption class=\"wp-element-caption\">Figure 3. External Camera Navigation Simulations<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<p>Figure 4 represents the live feed of the StereoCamera identifying an AprilTag. As the desired destination is identified as ARM 102, the top left corner will state \u201cMOVE\u201d until the correct AprilTag is detected. In this case, \u201ccorrect\u201d means the user\u2019s input room number matches the AprilTag seen within the camera&#8217;s frame. The .csv file provided allows for the comparison between the user\u2019s input and the respective tag being seen.&nbsp;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2023\/04\/Screen-Shot-2023-04-15-at-3.25.52-PM.png\" alt=\"\" class=\"wp-image-116\" width=\"534\" height=\"227\" srcset=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2023\/04\/Screen-Shot-2023-04-15-at-3.25.52-PM.png 976w, https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2023\/04\/Screen-Shot-2023-04-15-at-3.25.52-PM-300x128.png 300w, https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-content\/uploads\/sites\/210\/2023\/04\/Screen-Shot-2023-04-15-at-3.25.52-PM-768x327.png 768w\" sizes=\"auto, (max-width: 534px) 100vw, 534px\" \/><figcaption class=\"wp-element-caption\">Figure 4. Stereo Camera AprilTag Detection<\/figcaption><\/figure><\/div>","protected":false},"excerpt":{"rendered":"<p>AprilTags are a visual fiducial system used in robotics and for camera calibrations. This system is based on a near-optimal robust lexicographic coding system. Provided this, the changes in lighting conditions and modes of viewpoint have little to no effect on the design and coding system. Conceptually speaking, AprilTags can be compared to QR codes &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/apriltags\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;AprilTags&#8221;<\/span><\/a><\/p>\n","protected":false},"author":397,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"ngg_post_thumbnail":0,"footnotes":""},"class_list":["post-90","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-json\/wp\/v2\/pages\/90","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-json\/wp\/v2\/users\/397"}],"replies":[{"embeddable":true,"href":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-json\/wp\/v2\/comments?post=90"}],"version-history":[{"count":0,"href":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-json\/wp\/v2\/pages\/90\/revisions"}],"wp:attachment":[{"href":"https:\/\/engprojects.tcnj.edu\/robot-guide-dog\/wp-json\/wp\/v2\/media?parent=90"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}