{"id":93611,"date":"2014-02-01T06:55:18","date_gmt":"2014-02-01T04:55:18","guid":{"rendered":"http:\/\/mybroadband.co.za\/news\/?p=93611"},"modified":"2014-02-01T06:56:42","modified_gmt":"2014-02-01T04:56:42","slug":"surprisingly-simple-scheme-for-self-assembling-robots","status":"publish","type":"post","link":"https:\/\/mybroadband.co.za\/news\/technology\/93611-surprisingly-simple-scheme-for-self-assembling-robots.html","title":{"rendered":"Surprisingly simple scheme for self-assembling robots"},"content":{"rendered":"<p>In 2011, when an MIT senior named John Romanishin proposed a new design for modular robots to his robotics professor, Daniela Rus, she said, \u201cThat can\u2019t be done.\u201d<\/p>\n<p>Two years later, Rus showed her colleague Hod Lipson, a robotics researcher at Cornell University, a video of prototype robots, based on Romanishin\u2019s design, in action. \u201cThat can\u2019t be done,\u201d Lipson said.<\/p>\n<p>In November, Romanishin \u2014 now a research scientist in MIT\u2019s Computer Science and Artificial Intelligence Laboratory (CSAIL) \u2014 Rus, and postdoc Kyle Gilpin will establish once and for all that it can be done, when they present a paper describing their new robots at the IEEE\/RSJ International Conference on Intelligent Robots and Systems.<\/p>\n<p>Known as M-Blocks, the robots are cubes with no external moving parts. Nonetheless, they\u2019re able to climb over and around one another, leap through the air, roll across the ground, and even move while suspended upside down from metallic surfaces.<\/p>\n<p>Inside each M-Block is a flywheel that can reach speeds of 20,000 revolutions per minute; when the flywheel is braked, it imparts its angular momentum to the cube. On each edge of an M-Block, and on every face, are cleverly arranged permanent magnets that allow any two cubes to attach to each other.<\/p>\n<p>\u201cIt\u2019s one of these things that the [modular-robotics] community has been trying to do for a long time,\u201d says Rus, a professor of electrical engineering and computer science and director of CSAIL. \u201cWe just needed a creative insight and somebody who was passionate enough to keep coming at it \u2014 despite being discouraged.\u201d<\/p>\n<p><iframe loading=\"lazy\" src=\"http:\/\/video.mit.edu\/embed\/25913\/\" height=\"360\" width=\"560\" frameborder=\"0\"><\/iframe><\/p>\n<p><strong>Embodied abstraction<\/strong><\/p>\n<p>As Rus explains, researchers studying reconfigurable robots have long used an abstraction called the sliding-cube model. In this model, if two cubes are face to face, one of them can slide up the side of the other and, without changing orientation, slide across its top.<\/p>\n<p>The sliding-cube model simplifies the development of self-assembly algorithms, but the robots that implement them tend to be much more complex devices. Rus\u2019 group, for instance, previously developed a modular robot called the\u00a0<a href=\"http:\/\/publications.csail.mit.edu\/abstracts\/abstracts05\/rus4\/rus4.html\" target=\"_blank\">Molecule<\/a>, which consisted of two cubes connected by an angled bar and had 18 separate motors. \u201cWe were quite proud of it at the time,\u201d Rus says.<\/p>\n<p>According to Gilpin, existing modular-robot systems are also \u201cstatically stable,\u201d meaning that \u201cyou can pause the motion at any point, and they\u2019ll stay where they are.\u201d What enabled the MIT researchers to drastically simplify their robots\u2019 design was giving up on the principle of static stability.<\/p>\n<p>\u201cThere\u2019s a point in time when the cube is essentially flying through the air,\u201d Gilpin says. \u201cAnd you are depending on the magnets to bring it into alignment when it lands. That\u2019s something that\u2019s totally unique to this system.\u201d<\/p>\n<p>That\u2019s also what made Rus skeptical about Romanishin\u2019s initial proposal. \u201cI asked him build a prototype,\u201d Rus says. \u201cThen I said, \u2018OK, maybe I was wrong.\u2019\u201d<\/p>\n<p><strong>Sticking the landing<\/strong><\/p>\n<p>To compensate for its static instability, the researchers\u2019 robot relies on some ingenious engineering. On each edge of a cube are two cylindrical magnets, mounted like rolling pins. When two cubes approach each other, the magnets naturally rotate, so that north poles align with south, and vice versa. Any face of any cube can thus attach to any face of any other.<\/p>\n<p>The cubes\u2019 edges are also beveled, so when two cubes are face to face, there\u2019s a slight gap between their magnets. When one cube begins to flip on top of another, the bevels, and thus the magnets, touch. The connection between the cubes becomes much stronger, anchoring the pivot. On each face of a cube are four more pairs of smaller magnets, arranged symmetrically, which help snap a moving cube into place when it lands on top of another.<\/p>\n<p>As with any modular-robot system, the hope is that the modules can be miniaturized: the ultimate aim of most such research is hordes of swarming microbots that can self-assemble, like the \u201cliquid steel\u201d androids in the movie \u201cTerminator II.\u201d And the simplicity of the cubes\u2019 design makes miniaturization promising.<\/p>\n<p>But the researchers believe that a more refined version of their system could prove useful even at something like its current scale. Armies of mobile cubes could temporarily repair bridges or buildings during emergencies, or raise and reconfigure scaffolding for building projects. They could assemble into different types of furniture or heavy equipment as needed. And they could swarm into environments hostile or inaccessible to humans, diagnose problems, and reorganize themselves to provide solutions.<\/p>\n<p><strong>Strength in diversity<\/strong><\/p>\n<p>The researchers also imagine that among the mobile cubes could be special-purpose cubes, containing cameras, or lights, or battery packs, or other equipment, which the mobile cubes could transport. \u201cIn the vast majority of other modular systems, an individual module cannot move on its own,\u201d Gilpin says. \u201cIf you drop one of these along the way, or something goes wrong, it can rejoin the group, no problem.\u201d<\/p>\n<p>\u201cIt\u2019s one of those things that you kick yourself for not thinking of,\u201d Cornell\u2019s Lipson says. \u201cIt\u2019s a low-tech solution to a problem that people have been trying to solve with extraordinarily high-tech approaches.\u201d<\/p>\n<p>\u201cWhat they did that was very interesting is they showed several modes of locomotion,\u201d Lipson adds. \u201cNot just one cube flipping around, but multiple cubes working together, multiple cubes moving other cubes \u2014 a lot of other modes of motion that really open the door to many, many applications, much beyond what people usually consider when they talk about self-assembly. They rarely think about parts dragging other parts \u2014 this kind of cooperative group behavior.\u201d<\/p>\n<p>In ongoing work, the MIT researchers are building an army of 100 cubes, each of which can move in any direction, and designing algorithms to guide them. \u201cWe want hundreds of cubes, scattered randomly across the floor, to be able to identify each other, coalesce, and autonomously transform into a chair, or a ladder, or a desk, on demand,\u201d Romanishin says.<\/p>\n<p><em>Reprinted with permission of\u00a0<a title=\"MIT news\" href=\"http:\/\/web.mit.edu\/newsoffice\/\" target=\"_blank\">MIT News<\/a><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Small cubes with no exterior moving parts can propel themselves forward, jump on top of each other, and snap together to form arbitrary shapes &#8211; by Larry Hardesty<\/p>\n","protected":false},"author":340941,"featured_media":93613,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[36,22853,7699,6266,22855],"class_list":["post-93611","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technology","tag-active","tag-john-romanishin","tag-mit","tag-robot","tag-self-assembling-robots"],"_links":{"self":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/93611"}],"collection":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/users\/340941"}],"replies":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/comments?post=93611"}],"version-history":[{"count":0,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/93611\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/media\/93613"}],"wp:attachment":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/media?parent=93611"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/categories?post=93611"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/tags?post=93611"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}