{"id":3890,"date":"2019-12-03T23:39:28","date_gmt":"2019-12-03T22:39:28","guid":{"rendered":"http:\/\/dronesonen.usn.no\/?p=3890"},"modified":"2019-12-03T23:39:28","modified_gmt":"2019-12-03T22:39:28","slug":"group-02-project-report-week-13","status":"publish","type":"post","link":"https:\/\/dronesonen.usn.no\/?p=3890","title":{"rendered":"Group 02 \u2013 Project Report \u2013 Week 13"},"content":{"rendered":"\n<p><strong>Mechanical\u00a0<\/strong><\/p>\n\n\n\n<p>This week we finally got a hold of two more 24V fans which serves our purpose of creating enough pressure under the\u00a0board plate to make the disc \u201cfloat\u201d as we want it too.\u00a0To see how this works in\u00a0practice, watch the video below.\u00a0\u00a0<\/p>\n\n\n\n<figure class=\"wp-block-embed-youtube aligncenter wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-4-3 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Air flow test\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/aX0LgM7u86c?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption>Air Flow Test<\/figcaption><\/figure>\n\n\n\n<p>I have also used a lot of time finishing up all the documentation for\u00a0the modelling.\u00a0Making 2D drawings, exploded views and animation has taken a lot of time, especially since SolidWorks keeps crashing on the school computers due to\u00a0driver issues. These will hopefully be fixed soon, but\u00a0because of this I\u2019ve had to create two of each part, with and without toolbox components. This has resulted in\u00a0that\u00a0the final model\u00a0now is not that detailed. But all the parts where different toolbox\u00a0products have been used\u00a0can be found in the final delivery. Below\u00a0you can see some of the documentation, hereof\u00a02D drawings, exploded views and animations.\u00a0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"745\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-1024x745.png\" alt=\"\" class=\"wp-image-3892\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image.png 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-300x218.png 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-768x559.png 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em>Center Mount \u2013 Exploded View (w\/ B.O.M.)<\/em>\u00a0 <\/figcaption><\/figure><\/div>\n\n\n\n<figure class=\"wp-block-embed-youtube aligncenter wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Center Mount - Exploded View\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/8x5VKFIVD9g?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption> <em>Center Mount \u2013 Exploded View (Animation)<\/em>\u00a0 <\/figcaption><\/figure>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"737\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-1-1024x737.png\" alt=\"\" class=\"wp-image-3893\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-1.png 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-1-300x216.png 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-1-768x553.png 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em>Pipe Connector \u2013 Center Mount (2D)<\/em>\u00a0 <\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"736\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-2-1024x736.png\" alt=\"\" class=\"wp-image-3894\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-2.png 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-2-300x216.png 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-2-768x552.png 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em>Slider\u00a0\u2013 Center Mount (2D)<\/em>\u00a0 <\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"742\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-3-1024x742.png\" alt=\"\" class=\"wp-image-3895\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-3.png 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-3-300x217.png 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-3-768x557.png 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em>Board \u2013 Exploded View<\/em>\u00a0 <\/figcaption><\/figure><\/div>\n\n\n\n<figure class=\"wp-block-embed-youtube wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Board - Exploded View\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/jBnz0PGxgLs?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption> <em>Board\u00a0\u2013\u00a0Mounting Animation<\/em>\u00a0 <\/figcaption><\/figure>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"738\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-4-1024x738.png\" alt=\"\" class=\"wp-image-3896\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-4.png 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-4-300x216.png 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-4-768x554.png 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em>Stick\u00a0\u2013 Exploded View<\/em>\u00a0 <\/figcaption><\/figure><\/div>\n\n\n\n<figure class=\"wp-block-embed-youtube aligncenter wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Stick - Exploded View\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/nERNl3ZLrWU?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption> <em>Stick\u00a0\u2013 Mounting Animation<\/em>\u00a0 <\/figcaption><\/figure>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"737\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-5-1024x737.png\" alt=\"\" class=\"wp-image-3897\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-5.png 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-5-300x216.png 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-5-768x553.png 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em>Air Hockey Robot w\/ B.O.M.<\/em> Top Level<\/figcaption><\/figure><\/div>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"741\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-6-1024x741.png\" alt=\"\" class=\"wp-image-3898\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-6.png 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-6-300x217.png 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-6-768x556.png 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em> Air Hockey Robot w\/ B.O.M.<\/em> <em>Product Level<\/em><\/figcaption><\/figure>\n\n\n\n<p>All the files for the 3D modelling, hereof: Parts, Sub-Assemblies, Assemblies, 2D-drawings, Exploded Views, etc. can be downloaded and viewed through this link:&nbsp;<a href=\"https:\/\/drive.google.com\/open?id=1pQ7u_ta71Oe3a7rE9DYc6JI47PMYaHhT\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/drive.google.com\/open?id=1pQ7u_ta71Oe3a7rE9DYc6JI47PMYaHhT<\/a>&nbsp;&nbsp;<\/p>\n\n\n\n<p>The animations size\u00a0are\u00a0too\u00a0large and is therefore uploaded with the\u00a0youtube\u00a0links above.\u00a0<\/p>\n\n\n\n<p><strong>Electro<\/strong><\/p>\n\n\n\n<p>This week we were making some last changes in programming and combining our &#8220;electrical codes&#8221; with computer engineering coding, so that we removed all the bugs when we put it all together and finally, the whole (smart) system started working as we had planned in our first meetings at the beginning of the semester.<\/p>\n\n\n\n<p>We had to smooth out the surface over the goal line, so the puck can cross the line and get inside the goal. The problem is, because we couldn&#8217;t get any bigger plate that could fit all over the air hockey ring and over the goal surface, we don&#8217;t have any air flow inside the goal and this surface has to be as smooth as possible.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/lh6.googleusercontent.com\/TF33eVpwTp1xwzwEa_c3dJC7ROFnhPk5mzX3SwL36hYKkFig7Tb4z9VWUE2HS9NfvX_9TNB3fFsz_Cb0NsTqMQMEs0wYUkkgywa0XgrT22IsgqwiiCEWU794GYfXSVTMrP2xF9I\" alt=\"C:\\Users\\Jon A\u017eman\\Downloads\\IMG_20191203_231246.jpg\" \/><figcaption>Board Surface<\/figcaption><\/figure><\/div>\n\n\n\n<p>Score counting works with the laser ray aiming into the photo-resistor. That means that when the disc crosses a goal line, the laser ray gets cut and the resistance is changed and the system detects the change and counts it as a goal.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/lh6.googleusercontent.com\/rULmd7weF4V1mLuc7lrJ2WVw0_dOm8IcazXJTa4Vzg1iSR_EKLaTEMXEYVHNQPSJosiLEDeUQwVeuqntZeyB3-CARJgPJ5r1sYxkhf9IOt4wtBKtFjeNLNdAReuT9xkHVlLB2Xk\" alt=\"C:\\Users\\Jon A\u017eman\\Downloads\\IMG_20191203_181603.jpg\" \/><figcaption> <em>1: Laser aiming from one side with the ray<\/em> <\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/lh6.googleusercontent.com\/v0-KhYWi1aMZtqg_FduP3yaskO_IkXHHe6GKjqR1P97ntC0PNEWRC-80vx1lIWjg5_N5khL2fMWBAhMIvnFK9zM60fP166Bo4csut0KQZXvidZYhD0X6O_fkAa0eOWS0RYulbow\" alt=\"C:\\Users\\Jon A\u017eman\\Downloads\\IMG_20191203_181555.jpg\" \/><figcaption> <em>2: Photo-resistor with the laser ray (red dot) on it<\/em> <\/figcaption><\/figure><\/div>\n\n\n\n<p>At the end we screwed the joystick and final power switch on each side of the hockey table, in reach of a player. That way you (the player) can easily turn on the whole system and choose a game mode to play against the &#8220;unbeatable&#8221; computer.<br><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/lh3.googleusercontent.com\/28yuxd6ohbsTHsmJt7yPZiaBumhXHhPXGiQ9_d4KbhAyKVbKuY-D6buZ_tzaHf5tmlFGJ-sZFXyFnHLKVsGdby3lx4zmhD4ve3Ts6aqmNy6ZtkPzsDQgYscvC4GIahRp0kUo7v0\" alt=\"C:\\Users\\Jon A\u017eman\\Downloads\\IMG_20191203_181841.jpg\" width=\"324\" height=\"432\" \/><figcaption>System Power Switch<\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/lh4.googleusercontent.com\/CG8NuqdOgFWIyapizAHyHazt4sL3g54nrBM3926fHo41_wCzRRsTcVhIyxA_H0v1iwEFDLlGrlU68BGHxSaa6kHAxTskLMHUYpUMUWaxjsKOUygScw4IGeM8D9L45ag3FsEPBbY\" alt=\"C:\\Users\\Jon A\u017eman\\Downloads\\IMG_20191203_181833.jpg\" width=\"322\" height=\"429\" \/><figcaption>System Game Mode Selector<\/figcaption><\/figure><\/div>\n\n\n\n<p>Furthermore, Marc from electro has been working hard on the video, where the idea is to tell the story of a air hockey match set in Norway. Using this idea, the plan is to show a little bit of the whole process of the construction of the system, while the epic match between the human and the computer opponent is taking place. We will not be showing any clips here, as we want the entire video to be a surprise to go alongside the presentation on Friday!<\/p>\n\n\n\n<p><strong>Computer\u00a0<\/strong><\/p>\n\n\n\n<p>Following the successful implementation of the basic defense functionality last week, we discovered a couple of bugs we had to iron out together with the electrical students for the system to truly work:&nbsp;<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>While the functionality itself did work, it was far too slow, and was nowhere near unbeatable.\u00a0<\/li><li> The python program would frequently freeze when attempting to send data to the Arduino.\u00a0 <\/li><\/ol>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"http:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-1024x768.jpeg\" alt=\"\" class=\"wp-image-3891\" srcset=\"https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image.jpeg 1024w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-300x225.jpeg 300w, https:\/\/dronesonen.usn.no\/wp-content\/uploads\/2019\/12\/image-768x576.jpeg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption> <em>Kristian and Marc attempting to fix the issues<\/em>\u00a0 <\/figcaption><\/figure><\/div>\n\n\n\n<p>To solve 1), we began by researching if others had encountered this problem on the internet, at which point we found two prominent solutions: one was to reduce the amount of time the Arduino program waits for serial data, as it will default to 1000 milliseconds (1 second), and\u00a0the other was\u00a0to get rid of any unnecessary prints. By reducing the serial wait time using the\u00a0serial.setTimeout() function, and reducing this to 10 milliseconds, as well as getting rid of some prints, we observed a dramatic increase in response time.<br><br>To solve 2), we likewise began our research, and found that this was not an entirely uncommon occurrence and could seemingly occur when the program gets stuck when attempting to write to the serial port. Here, we found that the solution was to flush the serial port prior to writing with the\u00a0serial.flushInput() function, which will clear it before we transmit our new data.\u00a0 <br><br>Fixing these two issues have resulted in a reasonably competent computer opponent that we believe suffice as a proof-of-concept, but it is still not as fast as we would like.\u00a0In an effort to\u00a0further optimize our program, we began experimenting if the lighting of our board was static and uniform enough to use the default OpenCV color space: BGR, and if we could forego having to convert to HSV or some other color space. As we discovered\u00a0early on in the\u00a0project, converting the frame to the HSV color space necessitates a complex algorithm that is very\u00a0performance\u00a0heavy.\u00a0After a couple of hours of testing different masks and lighting conditions, we discovered that without some sort of external source of lighting that could evenly light the board, BGR was a no-go. This is a result of the bridge darkening parts of the board slightly, as well as the player\u2019s shadow frequently extending into their part of the board. We had ordered LED strips a couple of months ago, but these have not arrived yet, unfortunately. Consequently, we have decided to keep using the HSV color space, as this has given us the most flexibility and best results for our tracking with the lighting conditions we have.\u00a0 <\/p>\n\n\n\n<p>Below is a video briefly demonstrating the system in action, after our latest fixes.<\/p>\n\n\n\n<figure class=\"wp-block-embed-youtube wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-4-3 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Autonomous Air Hockey Demonstration 2\" width=\"500\" height=\"375\" src=\"https:\/\/www.youtube.com\/embed\/xXkv6l2D0zc?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption>Demonstration of the Air Hockey System<\/figcaption><\/figure>\n\n\n\n<p>The last couple of weeks has been more hectic than usual, which is normal for a project that is coming to an end. The integration and the components coming together is the hardest part. No matter how good you think \u201cyour\u201d part of the system works it is bound to meet some obstacles when subsystems\u00a0have to\u00a0start work together. Interfaces are challenging, mostly because it is then the different disciplines really\u00a0have to\u00a0work together as well as the fact that it is easy to lose the big-picture view of the system when working on a detail or a subsystem.<br><br>We also have been working on our presentation, graphical design, making illustrations, selecting material on what to say and who would say it. The time we are given for the presentation is short, so it is important to really think through everything and summarize the project in a concise manner. We tried to divide slides and presentation time equally among team members while maintaining the big-picture view of the project which is not an easy task. We are confident that we have done a good job on the presentation so far and will do it well when the day comes. If I would have to point out something that may (or may not) affect our presentation is the fact that we did not know the location of where we will present so the presentation style may or may not fit to the location\/situation.<br><br>We also did some team building like filming together outside and taking a \u201croad trip\u201d. We have gotten to know each other through the course of this project, and we all feel it has been a good experience overall. It is interesting and educational to work in a team that is not only multidisciplinary, but also multicultural. It goes without saying it&#8217;s fun when you work on a project that is as cool as ours!\u00a0 <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Mechanical\u00a0 This week we finally got a hold of two more 24V fans which serves our purpose of creating enough pressure under the\u00a0board plate to make the disc \u201cfloat\u201d as we want it too.\u00a0To see how this works in\u00a0practice, watch the video below.\u00a0\u00a0 I have also used a lot of time finishing up all the [&hellip;]<\/p>\n","protected":false},"author":65,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[51,52],"tags":[],"class_list":["post-3890","post","type-post","status-publish","format-standard","hentry","category-smart-systems-2019","category-the-unbeatable-air-hockey-team"],"_links":{"self":[{"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=\/wp\/v2\/posts\/3890","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=\/wp\/v2\/users\/65"}],"replies":[{"embeddable":true,"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3890"}],"version-history":[{"count":1,"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=\/wp\/v2\/posts\/3890\/revisions"}],"predecessor-version":[{"id":3942,"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=\/wp\/v2\/posts\/3890\/revisions\/3942"}],"wp:attachment":[{"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3890"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3890"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dronesonen.usn.no\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3890"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}