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Transducers Put the "Thrill" in Hydraulic-Powered Thrill Rides Despite contamination and daily high-speed hammering, magnetostrictive linear
transducers deliver rapid-fire fun for thousands of visitors You're James Bond, piloting a high-powered motorcycle down a dangerous mountain road. Your pulse races as you lean the speeding two-wheeler hard into a hairpin turn, slamming your body against the seat. Suddenly, with a loud clunk, you lurch sideways. Paramount's Great America theme park uses Micropulse linear position transducers in three-axis simulator chairs to assure high-speed motion that precisely matches movie action. When that would happen to riders at the Action FX Theater of Paramount's Great America theme park in Santa Clara, CA, it meant a thrilling multi-media ride had come to an abrupt and premature halt. Too often, the linear pots that controlled motion on the three-axis simulator chairs would glitch, turning the high-performance ride into something less than advertised, says Jose Rios, the theme park's maintenance technician for the ride chairs. Constant misreads and frequent downtime on the action theater's programmable chairs caused Great America engineers to switch to Micropulse linear position transducers, from Balluff Inc., Florence, KY. The non-contact, industrially-hardened transducers all but eliminate downtime due to wear, dirt or excessive vibration. They provide continuous, absolute position and velocity feedback to three hydraulic cylinders, each with 18-in. "throw" range, that provide a near-infinite combination of simultaneous up-and-down, side-to-side, and front-to-back motions. The transducers assure that the high-speed, high-force chair motion -- adopted from flight simulators -- precisely matches actions of a projected movie film. At present, this involves body-shaking car, plane and boat chases, breakneck downhill skiing and a host of other action stunts in the James Bond film short "A License to Thrill," excerpted from the full-length hit "A License to Kill." Potentiometer problems Potentiometer problems were disrupting chair action and spoiling the thrills. "Potentiometers just have a high rate of failure," says Rios. "The pots were causing what we call 'clunkers,'" the actual sound the ride would make as the pots wore out. Intermittent, faulty signals from the failing components would cause the chairs to get out of sync, slow down, or not move at all. In an effort to get longer use from the potentiometers, the Great America maintenance crew would sometimes take misfiring pots apart, clean and reinstall them -- a process that can take several hours. Even then, the pots were sure to fail again, says Rios. Crew members were having to check and service each chair daily to ensure continued operation. "Switching to the transducers eliminated all that," Rios points out. "It
sure saves us a lot of time and trouble." Design details Each Micropulse-equipped chair is hooked into the theater's programming source, an Allen Bradley PLC#2. Activated through the projectionist controls located above and behind the 40 -seat theater, the system signals the chairs precisely in sync with the actions on the screen. Signals register on a separate computer screen designed specifically for chair performance review and maintenance overview. Auto-tuning capability enables the transducers to compensate for any performance changes caused by temperature fluctuations. Running time for each show is about four minutes, which, taken with the time needed to usher visitors in and out, translates into about six shows every hour. The transducers control thousands of directional changes for the ride chairs during the course of one day, with chairs in constant, lightning-fast movement from the opening sequence to the end of the short film. --FR Non-contact, industrially-hardened Micropulse transducers all but eliminate downtime due to wear, dirt or excessive vibration. For more information: Circle 668 - Balluff Inc. or connect directly to their website via the [dfx/incl/99dfx.htm] |
