Las Vegas – When engineers initially designed motion-control system for the main stage of Cirque du Soleil’s Las-Vegas-based show KA, it was based on an open-loop system. But starting in 2010, stage control will change to a closed-loop system that helps improve reliability.

“There was a lack of visibility into the system that was keeping Cirque from maximizing motion control of the stage,” says Ian Hall, the lead engineer from Siemens assigned to the KA stage at the MGM Grand. He was part of a team of Siemens engineers that have been preparing this switch over for three years.

Siemens’ Manager of Mechatronics, Dr. Razvan Panaitescu, worked on the mechatronic analysis of the stage, which included analysis of the machine from mechanical, electronic, and electrical perspectives. “Think of it like a doctor examining the human body,” says Panaitescu. “The mechanical analysis looks at the structure like an orthopedic looks at your bones, the electrical analysis looks at components like motors that represent the muscles, and the electronic analysis looks at controls that function as the machine’s brain. But instead of looking at them separately, we look at them together to understand how they interact.”

In addition to building a digital prototype of the overall machine, Siemens engineers performed a multi-factor evaluation of kinematics, stiffness, mass, variable inertia, and other factors affecting the machine performance.

“With approximately 300 moves per day, we found the stage’s constant stop-start movements wore down the brake calipers rated for 100,000 cycles in about nine months,” explains Mark Castle, the Head of Automation at Cirque du Soleil. “Together, we found ways to use the