Navigating the World of Automation

By Richard Cadena

 

Let me just get this out there right off the bat - I'm not a rigger.

So what am I doing in an automation and control class? I'm glad you asked.

I've been involved in the production industry in one form or another for over twenty years and I've successfully dodged learning much about rigging and automation. Until now.

Some people have an aversion to math, some people have an aversion to heights; I have an aversion to taking responsibility for hanging things over people's heads. But I received an intriguing email about the Navigator class offered at Fisher Technology Services, Inc (FTSI). The more I thought about it the more appealing it sounded. Take some motors, a bunch of hardware, some electronics, and a bunch of software, put it all in one pot, simmer, stir, and viola, instant automation.

Okay, it turns out there's a little more to it than that, but that's kind of what goes into it.

So this Monday morning I found myself driving far north of downtown Las Vegas in search of FTSI. The GPS on my iPhone pretty much guided me into the front door of the 56,000 square foot facility across the street from the Las Vegas Motor Speedway.

I was directed to a smaller 5,000 facility behind the building where four Disney employees (Chuck Brandt, Christine Chan, and Brian McGuire), a freelance rigger (Mark O'Brien), and an employee of FTSI (Randy deCelle) were waiting to take the class.

The class was led by Dana Bartholomew, VP of FTSI and an affable, very knowledgeable guy with lots of interesting stories about automation. We started by touring the facilities and walking through the rental, fabrication, R&D, and tech areas. It didn't look much different than the dozens of production facilities I've seen around the world except instead of lights and trussing there were lots of winches, controllers, and peripheral gear. And since they fabricate practically everything in house, there was also CNC machines and a huge water jet cutter. The very high ceiling in the warehouse space was an indication of the kind of testing that goes on in there, and indeed there was a 3D automated camera rig set up temporarily.

Back in the class, we got a brief history lesson on the company. Scott Fisher and Joe Champelli both worked for Siegfried and Roy and the company's first job was the "Big Freakin' Roller" curtain in Cirque du Soleil's "O." Today they have systems installed or are installing systems in Hyperion Theatre, Le Rev, World of Color, Spiderman on Broadway, and they have contributed to movies such as "Green Goblin," "Avatar," and "Vacancy." They also supplied automation systems to Tait Towers and Show Rig.

Navigator is their control software and it was specifically designed to fly people. Therefore, it has many levels of safety, redundancy, and security, which is the key to making it work safely and reliably. In this class we'll spend three days learning the software before we go out in the warehouse and play with the hardware.

The hardware is made up of a variety of components. The muscle of the system is provided by a gear motor, which is the combination of a servo motor and a gear box. Coupled to the motor are two brakes - one motor brake and one secondary brake. The motor brake is rated for three times the output of the motor while the secondary brake is rated the same as the motor. On the back side of the motor is an absolute encoder and another encoder, an incremental encoder, is coupled to the winch drum. Both are used to track movement and when they get out of synch or they detect travel beyond the safe zones then it signals the controller which then stops the system. The drum is helically grooved and moves the load by taking up or letting out cable.

The system has a 10:1 safety factor, or as some people call it, a 10:1 factor of ignorance. That means that the brake can hold 10 times the rated load of the gear motor. Part of the safety of the system includes a series of stops that signal the console when the load travels beyond the normal limits as tracked by the encoders. There's a soft stop, a hard stop, and an emergency stop. Each is tracked by the encoders but they all react differently. The soft stop is normal end of travel and when it is reached it causes the controller to slow down and stop the motor. The hard stop just beyond the normal limits of travel and when it's tripped it stops the motor and trips the hard stop relay, which disables the system. It can be reset from the console. The emergency stop is set to the point at which damage may occur if the load travels beyond that point. When the emergency stop is triggered it opens the e-stop relay which removes power to the system and applies the brakes.

The stops work because the encoders are monitored by the Navigator software, which communicates with the axis control unit (ACU), and that, in turn, communicates with the motor interface board (MIB). The MIB converts the digital information to motor control signals and directly controls the motor. This feedback loop from the motor to the encoders to the software to the controls and back to the motor is what makes the system work.

Automating and motorizing machinery is nothing new. It's been going on since the beginning of the distribution of electricity. What has allowed it to progress to this level of sophistication is the speed and power of computer hardware and the capabilities of the software. Combine that with a feedback loop and multiple points of monitoring and it becomes incredibly fast, accurate, and safe.

The beauty of this system is that it draws from every corner of the entertainment industry: designers, riggers, electricians, technicians, programmers, operators, and carpenters. It employs the services of machinists, mechanical engineers, electrical engineers, software and hardware designers, consultants, and CAD operators. It represents the culmination of the sum total of much of the body of knowledge in the industry. It sits at the intersection of a range of disciplines and applies them in unique and creative ways. For example, imagine a rig with automated lights on RSC Lightlocks, each of which is on a carrier controlled by a Navigator system. Not only would the lights pan and tilt, but they could also move up and down the length of the truss while adjusting trim in real time. Or what if some automated lights were mounted on articulating robotic arms? Or what about putting automated lighting on a single motorized cart controlled by the automation system? The possibilities are practically limitless and the industry has only scratched its surface. That's what makes me think that automation just might be the most exciting area of the industry today.

For more information about FTSI and Navigator classes visit www.ftsi.com.