Fri. Mar 24th, 2023
Disney engineer Wathel Rogers in the control harness, on the left, used to program the movements of animatronic characters, with Walt Disney on the right.

Disney engineer Wathel Rogers in the control harness, on the left, used to program the movements of animatronic characters, with Walt Disney on the right.

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Animatronics have powered some of the most imposing creatures and characters from science fiction and fantasy movies: the alien queen in Aliensthe terminator inside The terminatorand jaws of Jaws (the key to top billing in Hollywood: be a robot). Even beloved little ET – van ET: the alien—was a pile of aluminum, steel, and foam rubber capable of 150 robotic actions, including wrinkling its nose. But while animatronics is a prized part of some of the most far-reaching movies in culture, it originated in much more mundane circumstances. According to the Disney archives, it started with a bird.

One of the things Walt Disney was known for was bringing animatronics (or what he called Audio-Animatronics at the time) to major stages in his company and elsewhere. But Disney did not discover or invent animatronics for entertainment use; rather he found it in a store. In a video on Disney’s site, Disney archivist Dave Smith tells a story of how one day in the early 1950s, while shopping at a New Orleans antique store, Disney came across a small cage containing a smaller mechanical bird, who swayed with his tail and wings. while you tweet tonelessly. He bought the trinket and took it back to his studio, where his technicians took the bird apart to see how it worked.

The bird that allegedly started it all, bought by Walt Disney in New Orleans in the 1950s.
Enlarge / The bird that allegedly started it all, bought by Walt Disney in New Orleans in the 1950s.

This led the Disney engineers to experiment with what eventually became Walt Disney’s Enchanted Tiki Room, a building filled with autographed animatronic birds, blooming flowers, and drumming tiki drummers. Disney was able to make the birds work years before computer programming, engineering, sound and motion came together in a usable way.

According to an article by the defunct Perseverance of vision, Audio-Animatronics character sounds were taped, like a bird chirping. When the tape was played, the sound would vibrate a metal tongue in the system. The vibration of the reed would close a circuit, allowing electricity to pass through it and move a pneumatic valve in the figure (in the case of a bird, opening its beak). When the sound stopped, the circuit reopened and the bird’s beak returned to its neutral, closed position. In this way, the movement depended on the sound, so that the two would always work together to create a realistic representation of a bird singing.

The Enchanted Tiki Room opened at Disneyland in 1962, first as a restaurant and then as a standalone attraction. Throughout, the implementation remained simplistic. Disney was initially motivated to bring robots to life as a form of real-life animation, essentially taking movies off the screen into three-dimensional space. But by the time the tiki room debuted, the team at Disney had quietly pursued a more ambitious goal: experimenting with more complex systems that humans could mimic. They came close.

Towards a complicated human-robot

While the tiki room was being developed in the 1950s, engineers at Disney were experimenting with “Project Little Man,” an animatronic figure intended to mimic a Buddy Ebsen dance routine. While they made some progress, the figure was rough.

From there, the team at Disney experimented for a while with a Confucius-esque animatronic character intended to stand in the foyer of a restaurant and serve up pearls of wisdom when questions are asked. That project fell by the wayside when Disney opted to work on an animatronic figure of President Abraham Lincoln instead, modeling the face after a real Lincoln cast in 1860, the year before he took office.

For much larger figures like Lincoln, Disney engineers had to create a system to control them that was more flexible. The digital system used for the Tiki Room birds above still worked for simple actions like blinking eyes or little finger movements, according to Perseverance of visionbut larger body movements required an analog system.

This was done in a number of different ways, but both were based on a system of voltage regulation and the generation of motion with tones. An increase or decrease in tension was used to activate the more complex types of movement in animatronic figures, according to Perseverance of vision. For example, if a figure’s neutral head position was leaning to the left, an increase in voltage would activate the hydraulics to move it to the right. A decrease would swing it back to the left and no voltage would swing it to neutral. It’s easy to imagine how the bird chirping on-off system described above would become alarmingly herky-jerky for, say, President Lincoln turning to look at you. To counteract this, the tension system allowed for smoother movements.

The animatronic president Lincoln is ready to give his speech.

The animatronic president Lincoln is ready to give his speech.

The voltage changes would be caused by audio tones superimposed on 35mm film stock indicating that it should increase or decrease. The engineering team used a transducer that would relate the voltage changes to changes in sound so they could record and play back motion.

Perseverance of vision states that a move would be rehearsed, perfected, and then ‘recorded’. An engineer would use a potentiometer joystick that applied and measured the voltage differences to a particular joint. Once he got the move down, he performed the gesture by generating the ups and downs of voltage with the potentiometer, and the transducer translated that into tones recorded on film. The engineers then played the track to see if the movement worked correctly.

This sounds simple enough for a single movement, but most animatronic figures’ acts were composed of many different movements coordinated with each other. For example, just raising an arm to point your finger to emphasize something they said would require shoulder, elbow, wrist, and finger movements all to happen in sequence. Movements for each joint for each action would be recorded on one reel and then all of the motion coils would be combined into a master tape. Perseverance of vision notes that for the Carousel of Progress exhibit put on by Disney at the 1964 World’s Fair, four narrators had a total of 120 actions all recorded on one 1-inch 32-track master tape.

The other solution also used voltage regulation, but it did not require a system of timed signals. Instead of working with a transducer and potentiometer on one joint at a time, engineers used a wearable control harness, seen in Dave Smith’s video, that was hooked up to an animatronic figure. The harness measures tension differences across the various joints and mimics the changes in the animatronic figure associated with it, recording the movements on tape. The harness had the advantage of being able to register complex multi-joint movements, but it required perfect performance from the wearer, who had to sit for hours to get the movements right.

The animatronic Lincoln used both types of movement, although due to maintenance and space constraints, the actual materials used to perform the necessary movements were improved between when Disney first started developing animatronics and when the figure debuted . For example, the engineering team later started integrating servo valves, which can translate digital signals into smooth movements and would have reduced the need for accurate voltage difference registrations for some movements.

The animatronic Lincoln debuted at the 1964 World’s Fair as part of the Illinois State Pavilion. “He” could rise from a chair and deliver excerpts from the president’s most famous speeches. “The audience was really surprised by this. They thought it was an actor up there on stage,” said Smith. Animatronics filled several other Disney exhibits at the fair, including “It’s a Small World” and the General Electric Carousel of Progress.

As animatronics circled again from being an expression of live animation to a special effect in movies, the importance of perfectly programming and coordinating their performances fell away. While some programming was and is still necessary, the need for a full illusion is rarely necessary. But even if it’s no longer the standard it once was, Disney’s systems for its birds and its robot president laid the groundwork for some of the movie’s most awesome showings.

By akfire1

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