{"id":1179,"date":"2018-12-07T15:18:02","date_gmt":"2018-12-07T20:18:02","guid":{"rendered":"https:\/\/makecoolthings.com\/?p=1179"},"modified":"2018-12-07T23:36:22","modified_gmt":"2018-12-08T04:36:22","slug":"wherein-i-overanalyze-disneys-next-step-towards-the-robot-apocalypse","status":"publish","type":"post","link":"https:\/\/makecoolthings.com\/?p=1179","title":{"rendered":"Wherein I (over)analyze Disney’s next step towards the robot apocalypse"},"content":{"rendered":"

As you all know, my brain does not work like that of normal people. [He says, making a grotesque understatement.]<\/strong> One particular gift\/curse granted me by this derangement of the mind<\/em>\u00a0is my innate ability to just mentally disassemble things I’m looking at, and\u2014regardless of complexity \u2014instantly understand how they work.\u00a0 Or, to put it another way:\u00a0I can see the Matrix.<\/em><\/p>\n

So I was doing my morning web browsing, when I spotted an article about an\u00a0animatronic attraction being constructed at Tokyo Disneyland. The animated gif heading the article caught my attention because the technology looked so advanced. And in the video<\/a>, they showed the inner workings of one of the characters’ arms for like three seconds. Read on for a better look at the arm, and my (over)analysis.<\/p>\n

The Animatronic Arm<\/h2>\n
\"\"<\/a>

Yes, I really did<\/em> capture three frames from the video and stitch them together to get this pic. No, I am not<\/em> right in the head.<\/p><\/div>\n

My (Over)Analysis<\/h2>\n

They\u2019re clearly not screwin\u2019 around here, these ain\u2019t some hokey old animatronics made out of welded steel, pneumatic cylinders, and fiberglass… That is some beautifully CNC-machined and anodized aluminium. Some real aerospace-grade engineering and design work, to be sure. I\u2019m guessing the plastic is\u00a0SLS<\/a>\u00a0nylon. Both for the material properties and because an SLS printer is a perfect fit for the in-house rapid-prototyping and production needs of an operation like this.\u00a0🤔<\/p>\n

As an enginerd<\/em>\u00a0and maker-of-things, I am in awe of this. All I\u00a0do<\/em>\u00a0is sit around designing crazy stuff, and even\u00a0I\u2019m<\/em>\u00a0learning things just from\u00a0looking<\/em>\u00a0at that picture!<\/p>\n

Take for example the wrist articulation. It has a deviation (side to side) axis driven by a servo in the forearm, connected via a linkage\u00a0across\u00a0<\/em>the wrist joint, to a pivot. (That\u2019s why there\u2019s two pivots. The other, central, one is the pivot where the hand is connected to the arm.)<\/p>\n

Except I\u2019m almost certain the wrist also has a flexion (bending) axis as well. There\u2019s no other reason for the wiring harness to continue on into the hand unless there\u2019s a servo in there, moving the wrist on what appears to be a pivot perpendicular to the other two pivot points… Which would mean that both the linkage for the deviation axis, and the main pivot for the wrist, aren\u2019t attached to the hand itself, but to a stationary part of this additional axis. (Because they have to be fixed, and not bend with the hand.)<\/p>\n

[Edit: The more I look at it, the more I’m not completely certain the deviation axis is moved by a servo. If it’s a servo, it shouldn’t be necessary to physically restrict the movement, as you can see on the forearm end of the linkage. Unless that’s just a failsafe. I wouldn’t think any of it would be pneumatic though, traditionally pneumatics aren’t responsive enough to get these kinds of performances.🤔 I also have yet to figure out where the actuator for the flexion axis is, or how it’s connected. One thought is that it’s either a hollow bore or double-shaft servo, and the flexion axis’ stationary pivot is attached to the shaft, while the motor is mounted to the hand. So the motor<\/em> is the thing which moves, not the shaft.]<\/p>\n

[Edit2: I\u00a0did not know<\/em> that pneumatic servo rotary drives were even a thing.<\/em>🤨 Looking at the elbow, it’s entirely possible that they are employed here. I imagine they have much finer control than traditional pneumatic actuators like pistons. I wonder what their holding-torque to size\/weight ratio is versus regular electromagnetic steppers and servos.🤔]<\/p>\n

*sigh*<\/em>\u00a0[Opens Fusion 360 and creates new project file]<\/strong><\/p>\n

The exterior is also quite impressive. I wonder what the material is they use… From the facial animation, it looks fairly flexible. But other evidence suggests maybe not\u00a0that<\/em>\u00a0flexible?<\/p>\n

They seem to use clever costuming to make sure you never see Belle\u2019s elbow joints\u2014telling me they\u2019re either not covered, or the covering does something unsightly during acute bends \u2014and clever tricks of animation and body language to make it seem like her neck has more range of motion than it does; By my estimate she can only turn her head +\/- 15 degrees at most\u2014less than a quarter a human\u2019s range, nevermind an animated character, often employing exaggerated motion \u2014so they turn her whole body to give those subtle head movements a wider arc. I didn\u2019t even notice at first. I figure the limited range of motion is probably an issue like the elbow; any more and the outer covering material does something unsightly, except unlike the elbow, they can\u2019t just hide it. I doubt it\u2019s due to the complexity of the mechanics in the head, the wiring harness running up there shouldn\u2019t be that extensive. (Plus there\u2019s special wire for situations like this; rated to withstand being seriously bent in millions of operations in a piece of machinery.)<\/p>\n

I\u2019m quite interested in the software side as well. Looks like they\u2019re animating the actual animatronics in Maya, not just doing a previz animatic or something. Did they also model the characters\u2019 external appearances in Maya? (Or maybe 3ds Max?) I wonder how deep their Autodesk workflow goes… Are the inner workings designed in Fusion 360 and\/or Inventor, or do they use a different CAD<\/acronym> package, like SolidWorks? 🤔<\/p>\n

I wonder if they outsource the machining work on those aluminium parts, or if the park has a ridiculous Mori-Seiki VMC or something in the machine shop, for maintaining the attractions… (At the very least they send the parts out for anodizing. You don\u2019t get a finish like that under anything less than proper industrial conditions.❤)<\/p>\n

tl;dr: This whole thing is quite the feat of engineering, made possible by the work of what are clearly some very smart and talented people, pretty much for the sole purpose of entertaining children. (Not saying that\u2019s a bad thing, just framing it with my usual sarcasm to make sure we all recognize the overall absurdity.😂) And I have SO. MANY. QUESTIONS.<\/p>\n

Anyway, there goes my whole damn weekend. I\u2019m gonna go design a model of this arm I can 3D print and drive with hobby servos, because nothing says \u201cWorld-Class Enginerd\u201d like having a functional robotic arm just sitting on your workbench for giggles.<\/p>\n

Because I can.<\/em><\/p>","protected":false},"excerpt":{"rendered":"

As you all know, my brain does not work like that of normal people. [He says, making a grotesque understatement.] One particular gift\/curse granted me by this derangement of the mind\u00a0is my innate ability to just mentally disassemble things I’m looking at, and\u2014regardless of complexity \u2014instantly understand how they work.\u00a0 Or, to put it another […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"bgseo_title":"","bgseo_description":"","bgseo_robots_index":"","bgseo_robots_follow":"","jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[],"wf_post_folders":[],"class_list":["post-1179","post","type-post","status-publish","format-standard","hentry","category-blogposts"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p6NlLW-j1","_links":{"self":[{"href":"https:\/\/makecoolthings.com\/index.php?rest_route=\/wp\/v2\/posts\/1179","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/makecoolthings.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/makecoolthings.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/makecoolthings.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/makecoolthings.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1179"}],"version-history":[{"count":6,"href":"https:\/\/makecoolthings.com\/index.php?rest_route=\/wp\/v2\/posts\/1179\/revisions"}],"predecessor-version":[{"id":1182,"href":"https:\/\/makecoolthings.com\/index.php?rest_route=\/wp\/v2\/posts\/1179\/revisions\/1182"}],"wp:attachment":[{"href":"https:\/\/makecoolthings.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1179"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/makecoolthings.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1179"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/makecoolthings.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1179"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/makecoolthings.com\/index.php?rest_route=%2Fwp%2Fv2%2Fwf_post_folders&post=1179"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}