https://spectrum.ieee.org/disney-robot-2668135204 [ ] IEEE.orgIEEE Xplore Digital LibraryIEEE StandardsMore Sites Sign InJoin IEEE Disney's Robots Use Rockets to Stick the Landing Share FOR THE TECHNOLOGY INSIDER Search: [ ] Explore by topic AerospaceArtificial IntelligenceBiomedicalClimate TechComputing Consumer ElectronicsEnergyHistory of TechnologyRoboticsSemiconductors TelecommunicationsTransportation IEEE Spectrum FOR THE TECHNOLOGY INSIDER Topics AerospaceArtificial IntelligenceBiomedicalClimate TechComputing Consumer ElectronicsEnergyHistory of TechnologyRoboticsSemiconductors TelecommunicationsTransportation Sections FeaturesNewsOpinionCareersDIYEngineering Resources More NewslettersPodcastsSpecial ReportsCollectionsExplainersTop Programming LanguagesRobots Guide /IEEE Job Site / For IEEE Members Current IssueMagazine ArchiveThe InstituteThe Institute Archive For IEEE Members Current IssueMagazine ArchiveThe InstituteThe Institute Archive IEEE Spectrum About UsContact UsReprints & Permissions /Advertising / Follow IEEE Spectrum Support IEEE Spectrum IEEE Spectrum is the flagship publication of the IEEE -- the world's largest professional organization devoted to engineering and applied sciences. Our articles, podcasts, and infographics inform our readers about developments in technology, engineering, and science. Join IEEE Subscribe About IEEEContact & SupportAccessibilityNondiscrimination PolicyTerms IEEE Privacy PolicyCookie PreferencesAd Privacy Options (c) Copyright 2024 IEEE -- All rights reserved. A not-for-profit organization, IEEE is the world's largest technical professional organization dedicated to advancing technology for the benefit of humanity. Enjoy more free content and benefits by creating an account Saving articles to read later requires an IEEE Spectrum account The Institute content is only available for members Downloading full PDF issues is exclusive for IEEE Members Downloading this e-book is exclusive for IEEE Members Access to Spectrum 's Digital Edition is exclusive for IEEE Members Following topics is a feature exclusive for IEEE Members Adding your response to an article requires an IEEE Spectrum account Create an account to access more content and features on IEEE Spectrum , including the ability to save articles to read later, download Spectrum Collections, and participate in conversations with readers and editors. For more exclusive content and features, consider Joining IEEE . Join the world's largest professional organization devoted to engineering and applied sciences and get access to all of Spectrum's articles, archives, PDF downloads, and other benefits. Learn more - Join the world's largest professional organization devoted to engineering and applied sciences and get access to this e-book plus all of IEEE Spectrum's articles, archives, PDF downloads, and other benefits. Learn more - CREATE AN ACCOUNTSIGN IN JOIN IEEESIGN IN Close Access Thousands of Articles -- Completely Free Create an account and get exclusive content and features: Save articles, download collections, and talk to tech insiders -- all free! For full access and benefits, join IEEE as a paying member. CREATE AN ACCOUNTSIGN IN RoboticsGuest Article Disney's Robots Use Rockets to Stick the Landing Water rockets help flying robots make an entrance without it being their last Morgan Pope 12 May 2024 5 min read Three people in hard hats stand back from a white plume coming downwards from a raised object Richard-Alexandre Peloquin, Tony Dohi, and Bill Sturgeon observe an early test of the full-system rocket test. Disney Research It's hard to think of a more dramatic way to make an entrance than falling from the sky. While it certainly happens often enough on the silver screen, whether or not it can be done in real life is a tantalizing challenge for our entertainment robotics team at Disney Research. --------------------------------------------------------------------- Falling is tricky for two reasons. The first and most obvious is what Douglas Adams referred to as "the sudden stop at the end." Every second of free fall means another 9.8 m/s of velocity, and that can quickly add up to an extremely difficult energy dissipation problem. The other tricky thing about falling, especially for terrestrial animals like us, is that our normal methods for controlling our orientation disappear. We are used to relying on contact forces between our body and the environment to control which way we're pointing. In the air, there's nothing to push on except the air itself! Finding a solution to these problems is a big, open-ended challenge. In the clip below, you can see one approach we've taken to start chipping away at it. The video shows a small, stick-like robot with an array of four ducted fans attached to its top. The robot has a piston-like foot that absorbs the impact of a small fall, and then the ducted fans keep the robot standing by counteracting any tilting motion using aerodynamic thrust. Two people outdoors holding a tall silver object.Raphael Pilon [left] and Marcela de los Rios evaluate the performance of the monopod balancing robot.Disney Research The standing portion demonstrates that pushing on the air isn't only useful during freefall. Conventional walking and hopping robots depend on ground contact forces to maintain the required orientation. These forces can ramp up quickly because of the stiffness of the system, necessitating high bandwidth control strategies. Aerodynamic forces are relatively soft, but even so, they were sufficient to keep our robots standing. And since these forces can also be applied during the flight phase of running or hopping, this approach might lead to robots that run before they walk. The thing that defines a running gait is the existence of a "flight phase" - a time when none of the feet are in contact with the ground. A running robot with aerodynamic control authority could potentially use a gait with a long flight phase. This would shift the burden of the control effort to mid-flight, simplifying the leg design and possibly making rapid bipedal motion more tractable than a moderate pace. A man with silvery beard and mustache wearing safety googles and headphones sits in front of a mechanism on the floor.Richard Landon uses a test rig to evaluate the thrust profile of a ducted fan.Disney Research In the next video, a slightly larger robot tackles a much more dramatic fall, from 65' in the air. This simple machine has two piston-like feet and a similar array of ducted fans on top. The fans not only stabilize the robot upon landing, they also help keep it oriented properly as it falls. Inside each foot is a plug of single-use compressible foam. Crushing the foam on impact provides a nice, constant force profile, which maximizes the amount of energy dissipated per inch of contraction. In the case of this little robot, the mechanical energy dissipation in the pistons is less than the total energy needed to be dissipated from the fall, so the rest of the mechanism takes a pretty hard hit. The size of the robot is an advantage in this case, because scaling laws mean that the strength-to-weight ratio is in its favor. The strength of a component is a function of its cross-sectional area, while the weight of a component is a function of its volume. Area is proportional to length squared, while volume is proportional to length cubed. This means that as an object gets smaller, its weight becomes relatively small. This is why a toddler can be half the height of an adult but only a fraction of that adult's weight, and why ants and spiders can run around on long, spindly legs. Our tiny robots take advantage of this, but we can't stop there if we want to represent some of our bigger characters. Two people kneel on the floor working on a silver contraption.Louis Lambie and Michael Lynch assemble an early ducted fan test platform. The platform was mounted on guidewires and was used for lifting capacity tests.Disney Research In most aerial robotics applications, control is provided by a system that is capable of supporting the entire weight of the robot. In our case, being able to hover isn't a necessity. The clip below shows an investigation into how much thrust is needed to control the orientation of a fairly large, heavy robot. The robot is supported on a gimbal, allowing it to spin freely. At the extremities are mounted arrays of ducted fans. The fans don't have enough force to keep the frame in the air, but they do have a lot of control authority over the orientation. Complicated robots are less likely to survive unscathed when subjected to the extremely high accelerations of a direct ground impact, as you can see in this early test that didn't quite go according to plan. In this last video, we use a combination of the previous techniques and add one more capability - a dramatic mid-air stop. Ducted fans are part of this solution, but the high-speed deceleration is principally accomplished by a large water rocket. Then the mechanical legs only have to handle the last ten feet of dropping acceleration. Whether it's using water or rocket fuel, the principle underlying a rocket is the same - mass is ejected from the rocket at high speed, producing a reaction force in the opposite direction via Newton's third law. The higher the flow rate and the denser the fluid, the more force is produced. To get a high flow rate and a quick response time, we needed a wide nozzle that went from closed to open cleanly in a matter of milliseconds. We designed a system using a piece of copper foil and a custom punch mechanism that accomplished just that. Two photos show someone on a ladder manipulating a small tank on the left, and on the right a black cylindar with a clear tube out of the bottom and splashing water coming up from the ground.Grant Imahara pressurizes a test tank to evaluate an early valve prototype [left]. The water rocket in action - note the laminar, two-inch-wide flow as it passes through the specially designed nozzleDisney Research Once the water rocket has brought the robot to a mid-air stop, the ducted fans are able to hold it in a stable hover about ten feet above the deck. When they cut out, the robot falls again and the legs absorb the impact. In the video, the robot has a couple of loose tethers attached as a testing precaution, but they don't provide any support, power, or guidance. "It might not be so obvious as to what this can be directly used for today, but these rough proof-of-concept experiments show that we might be able to work within real-world physics to do the high falls our characters do on the big screen, and someday actually stick the landing," explains Tony Dohi, the project lead. There are still a large number of problems for future projects to address. Most characters have legs that bend on hinges rather than compress like pistons, and don't wear a belt made of ducted fans. Beyond issues of packaging and form, making sure that the robot lands exactly where it intends to land has interesting implications for perception and control. Regardless, we think we can confirm that this kind of entrance has-if you'll excuse the pun-quite the impact. From Your Site Articles * How Disney Packed Big Emotion Into a Little Robot > * Imagineer Morgan Pope Uses Electromagnetism to Spark Emotions > Related Articles Around the Web * Disney Research > disney researchrocketsrobotics {"imageShortcodeIds":[]} Morgan Pope Morgan Pope is a research scientist at Disney Research in Glendale, Calif. He joined Disney after graduating from Stanford, where he focused on building small robots that could jump, perch, and climb. The Conversation (0) two men posing for a portrait with electronics on a table in front of them EnergySemiconductorsNews This Microcapacitor Charges 100 Million Times Faster Than Lithium-ion Batteries 4h 3 min read woman standing at podium speaking and using her hands in a black dress The InstituteIEEE Member NewsCareersProfile This Member Gets a Charge from Promoting Sustainability 4h 5 min read An aerial view of a construction site of a silver building SemiconductorsNews U.S. Fab Capacity Could Triple in a Decade 9h 3 min read Related Stories RoboticsNews Video Friday: Robot Bees RoboticsNewsHumanoid Robots Video Friday: Loco-Manipulation RoboticsNews How Field AI Is Conquering Unstructured Autonomy