Automation and Ethernet Combine for 3D Disney Attraction
Core to the idea of Disney’s new "Toy Story Midway Mania" ride are the recreation and updating of the classic midway games such as the ring toss, dart throwing, and plate breaking, along with integration of the well-known "Toy Story" characters. Disney Imagineers developed the idea of making it all happen in a 3D environment as guests are transported from game to game in vehicles crafted to look like amusement park ride cars from the early twentieth century. And just like in the original midway games, points are calculated and prizes are won. But now it all happens virtually.
To take the idea from storyboard to reality, Disney engineers had to devise a way to seamlessly combine traditional ride control and show control with advanced gaming techniques, scoring technologies, and practical show gags (including bursts of air and sprinkles of water).
To handle the expected crowds, 20 vehicles move guests through the attraction on two tracks, with each vehicle holding eight people (two, double-sided carts are positioned on each vehicle and hold 2 riders per side). The vehicles stop in front of a screen displaying a 3D moving image of a midway game featuring "Toy Story" characters–one screen for each 2-person cart–for guests to take aim and do their best to score as many points as possible.
Guns, which look like small cannons, are mounted on lapbars to allow for positioning at the correct level for each guest, regardless of size. The guns are operated by a pull-string mechanism rather than a button or trigger due to the pull string’s ability to better withstand high volume of use. Objects ranging from darts and rings to paintballs and baseballs–dependent upon the game being shown on the screen–appear on the screen as if propelled from the guns when the pull strings are tugged by guests.
Two sets of control systems–a ride control system and a game control system–are required to manage the vehicle movement through the attraction as well as the interaction between the guests and the action on screen.
Each vehicle is equipped with Siemens Simatic power supplies, a Simatic S7 315 PLC with centralized I/O (32 channel discrete input and 32 channel discrete output modules) for vehicle control, Simatic CP343-1 lean communications processor, Simatic FM350-2 counter module, and a Scalance W client module for wireless communication. An industrial PC IL43 running WinCC Flexible 2007 Runtime 2048 Tags and Step7 v5.4 Professional is used for diagnosis and visualization of the ride. The S7 315 PLC controls the vehicle’s profile (speed and spin direction to assure orientation with the screen) and communicates the position of vehicle along the track throughout the ride.
An S7 319 PLC with remote I/O is used for wayside control. Distinct vehicle movement, such as run, jog, and stop, is handled by the wayside controls for each zone of the attraction. There are some 400 zones total in the ride–one of the largest zone counts ever deployed by Disney. The vehicle identifies itself at each scene through a signal sent to the wayside computer. Each zone has its own unique communications signals to manage ride progression, which are handled by 49 Siemens ET200S-PN remote I/O stations, each with several four channel discrete input high feature modules, four channel 0.5A discrete outputs, and a few two channel RO NO relay outputs.
Communication between the onboard and wayside computers is handled over Ethernet via Profinet cabling and protocol using Scalance X208 switches. In addition, Ethernet is used for all communications throughout the ride–within and between the ride and game control systems.
Olaf Scheel, Siemens Energy & Automation OEM program manager for Disney, notes that Disney has used Ethernet before, "but not as the control bus system to collect I/O data to control a ride."
He adds that the ride and game control demands of the "Toy Story Midway Mania" attraction, in addition to the broad acceptance and understanding Ethernet, made its use a simple choice. "Everyone understands Ethernet," he says. "It’s easy to install and easy to diagnose if there are problems."
"This is the first time Disney has used Ethernet throughout a ride," says Jody Gerstner, executive director, Show Systems Group, Disney. "We’ve watched many of our commercial systems move from proprietary to Ethernet over the years. We started using it in our audio systems and then moved it into show control.
"With ride control, we tested several different fieldbuses, but as rides became larger in scale, they demanded that we use remote I/O. As we looked at the Siemens product line, the ET200 with high feature I/O enabled us to complete our suite of subsystems using Ethernet. This gave us an Ethernet-based Profinet system with smart diagnostics at the far end of the system that could report back broken wire detection, short circuits, and any other fault detection for quick recovery."
Four Pepperl + Fuchs proximity sensors in each vehicle read absolute position of the car in the attraction by reading binary codes along track. In addition, a Banner laser sensor is used as a fine positioning sensor by reading strips placed on the floor along the track. Scalance W access point modules couple sensor communications onboard and offboard through a leaky coax cable installation along the track to the vehicles’ onboard Scalance W client modules. A Weidmuller unmanaged 8-port Industrial Ethernet switch handles connectivity in the vehicle gun turrets, linking the wireless system, the PLC, and game control computers.
The ride control room houses just two cabinets with systems for handling power distribution and safety. Also in the cabinet is a Siemens WinCC Flexible Runtime HMI so operators can "see" where vehicles are at in the attraction from the control room and determine what fault happened, when it happened, and where it happened.
Onboard each vehicle are two SEW Eurodrive motors for propulsion. According to Gerstner, a basic master/slave arrangement is used for running the motors and drives.
To recognize how each gun is being pointed in order to interact in a realistic way with the game being projected on the screen, each vehicle’s seating compartment houses a small Windows XP vehicle game computer. These computers gather data from the encoders in the gun to determine pitch, yaw, and height, as well as the position of the turret on which the gun is mounted. These four measurements are summarized into a data packet that is sent offboard to the gaming system.
A distribution system in the control room receives all this data (20 vehicles x 4 computers per vehicle = 80 computers all streaming data continuously into the system) over Ethernet into a wayside game computer, before being communicated to the nearly 200 computers in game system room that operate the on-screen games.
"Every screen in the attraction has a Hewlett-Packard game computer that receives data from the wayside computer," Gerstner says. "At that point, mathematics takes over. An algorithm takes all encoder values and calculates a position on the screen where the projectile should emanate from the gun that the guest is pointing and firing. It even calculates for the arc of the gun. A computer-generated image is then created and sent via fiber link to the projector and to the 3D active polarizer to produce the image and project it on the screen."
An image for the left eye and the right eye is produced by the game computers. Screen polarization synchronizes images sent from the computers so that a 3D image is rendered and perceived by the guest in 3D thanks to the special glasses we’re all familiar with from viewing 3D movies.
Points are collected along the way by the game system and communicated back to the onboard PC to display scores in the vehicle so guests can see how they’re doing. They are also told how accurate they are.
The game system also sends signals to the show control system to fire air cannons and other effects during the ride. If you pop a water balloon, for example, you get hit with a squirt of water.
All game and show system communications are handled by 100baseT Ethernet, says Gerstner, who adds that only about 10% of the Ethernet system is used at any one time.
"It’s actually less data being transmitted than you would imagine," he says. The high-end computers handle it all. Nothing had to be custom designed."
– Greenfield is editorial director of Control Engineering. He can be reached at david.greenfield(at)reedbusiness.com