cyberneticzoo.com

ROMAC, THE PNEUMATIC MUSCLE
Actuator pulls 10,000 pounds using 60 psi
A pneumatic actuator based on the principle of the human biceps has come to our attention in the form of a patent disclosure. The ROMAC, under development by MacDonald Detwiller & Associates of Richmond, British Columbia, Canada, works on low-pressure (shop) air and can lift over 200 pounds using 60 psi. The device weighs one pound. Its pulling force is said to exceed 10,000 pounds, rendering it superior to conventional pneumatic cylinders and nearly in the range of comparable hydraulic cylinders.
The flexible walls of the ROMAC are not designed to work as elastometers. Rather, the geometry of the individual pyramid elements allows for greater contraction. Additionally, the wire restraining cables and pyramid elements are combined into a "single surface" actuator designed to eliminate sliding friction during contraction, reducing wear on the soft parts and extending service life.
The device operates only under tension. Like the human biceps, it bulges in the middle as it contracts and flattens with
extension. In Photos 1 and 2, the ROMAC is manually manipulated by means of a lever to demonstrate its flexed and extended configurations. The potential contraction is 50 percent. The actuator is said to provide an extremely high force at the beginning of contraction, decreasing rapidly to zero at approximately 50 percent of contraction (Figure 1). The ROMAC's other advantages, as described, include the following:
• It is pneumatically powered but can also work with low-pressure hydraulics.
• It is leak-free, with no sliding seals and no static friction.
• It can be fabricated without metallic parts. (Fiber glass could be substituted for wire in the restraining cables.)
• It can be configured to do precision closed-loop control tasks.
• In opposing pairs, it can provide open-loop proportional control with inherently stiff operating characteristics.
Because of its high initial pulling force and its ability to perform in hostile surroundings, the ROMAC is expected to number among its future applications robotics, prosthetics, and nuclear and space environments.

[Source:The Robotics Age Nov 1985 – Edited by Stephanie vL Henkel]

Like the muscle used in Tim Jones' arm, the ROMAC is another example of the Netted-type of Pneumatic Artificial Muscle (PAM).

Axially contractable actuator by Guy Immega and Mirko Kukolj  
Patent number: 4939982
Filing date: Oct 16, 1985
Issue date: Jul 10, 1990

See full patent details here.

Grodski and Immega used ROMACs to control a 1-dof teleoperated arm by means of the myoelectric signals taken from a human operator's biceps and triceps. The operator can thus make the robot arm move without having to move his own. Independent position and stiffness control of the robot arm is achieved by regulating the ROMAC gauge pressures proportional to the operator's EMG signal output. Visual feedback to the operator is necessary.

Myoelectric control of actuators Juliusz J. Grodski et al
Patent number: 4964061
Filing date: Jul 5, 1989
Issue date: Oct 16, 1990

See full patent here.

The popularisation of “Man-Amplifiers” was largely due to the movie “Aliens” directed by James Cameron and released in 1986. Earlier scenes introduce it as it is, a power loader for heavy materials. Ripley later uses it as an equaliser for a “mano e mano” with the queen alien.

Earlier concept by Syd Mead.

Later designs by James “Jim” Cameron himself.

See the earlier 1967 “The Ambushers” movie with its Power Loader here.

Copy of original artwork.

Labyrinth scene with Humongous:

Excerpt from Inside the Labyrinth:

Check Youtube for clips on "The Making of the Labyrinth".

The text for Inside the Labyrinth documentary was originally transcribed by Stephanie Massick.

JIM HENSON: "It seemed like right late in the story what we wanted was for our heroes to come up against some huge obstacle, something worse than anything they'd encountered so far. And we came up with the idea of building the largest puppet we'd ever built."

GEORGE GIBBS (special effects supervisor): "Jim asked us about last January. He said, 'Boys, I¹d like a fifteen-foot high giant.' We said, 'Oh yeah. Very interesting.' Lots of people had tried to make fifteen-foot giants that walk and throw their arms around. They hadn't been very successful. So it was a challenge, really. So, we decided how we were going to make it and we went ahead and made all the mechanics and everything work wonderfully. When the body was produced in fiberglass, it just wouldn't work, because the fiberglass wouldn¹t flex. Fortunately for us, we had our foam expert. And he developed a foam for us with skin, skin that would flex without looking rubbery. We made the foam look like steel armor."

JIM HENSON: "He weighs . . . I don't know how much. Lots. With all the rig and all the hydrolics, the thing has to be several tons. And so this was the largest, most complicated thing we'd ever built. We didn't have very long to build it, probably two to three months."

GEORGE GIBBS: "One man could operate the whole thing. In the old days, we'd have probably had five or six guys all at different levers, working hydrolics. But one man operates the whole of Humongous all by himself, makes him walk forward, makes his body spin 'round, makes him bow down, makes his arms swing the ax. And it's all done with hydrolics. Every move his arm makes, the arms of Humongous make exactly the same move."

JIM HENSON: "When George first showed me Humongous in action, it was really an amazing thing, to just stand there and have this large thing walk toward you. It's one of the most awesome sights in the world."

The walking animatronic.

Humongous was suspended by a horizontal beam in its back to a rolling platform on rails.

Radio-controlled eye movements.

The Waldo being used to control Humongous' right arm.

Close-up of animatronic walking frame.

Hoggle at the controls. Although there are electrical switches, Humongous was a "steam man".

Humongous from Labyrinth Guide by Chaotica.