Like many of the coolest applications, innovations from one industry are used in another industry to solve unique challenges. For example, Founder and Managing Director of Simtec Group, Bernd Kaugmann, used his extensive flight simulator expertise to enter the market for automobile component testing systems as well as entertainment applications. Today, custom-tailored motion simulator systems from Simtec can be found in entertainment theme parks, 4D theaters, and museums around the world. With its development of Screenflite®, Simtec has entered the digital signage field as well. Resembling a kinetic piece of art, the media information system catches people’s attention in airport terminals, train stations, or shopping malls. 

Simtec’s next generation of indoor attractions includes its Hexaflite® Flying Theater. The moving platform, featuring six degrees of freedom, is surrounded by a spherical projection screen with a diameter of up to 23 meters. After spectators have taken their seats, the platform tilts into a vertical position so that the audience sits directly in front of the giant screen. Linear acceleration ranging from ±0.7 g and ±1 g and rotations of ±15 to 20 degrees around all axes and the perfect synchronization with the projected images and special effects combine to generate a spectacular, highly dynamic flight-like experience that fully immerses the audience in the screen action.

The moving platform is controlled by a Beckhoff CX5140 Embedded PC with a multi-touch Control Panel and TwinCAT 3 automation software. The nearly unlimited network expandability of EtherCAT and the high data transmission rate make it the ideal fieldbus system for such a large-scale project. According to Christian Spoer, Team Leader Software Engineer, “EtherCAT branching makes any network topology possible. Simtec also takes advantage of the redundancy supported by EtherCAT.” The complex safety solution for the motion system is based on approximately 100 digital TwinSAFE terminals in IP20 and local TwinSAFE I/O modules in IP65. In addition, four EL6910 TwinSAFE Logic terminals are incorporated and communicate with each other as well as with the higher-level CX5140. The signal and interface diversity of the Beckhoff I/O modules allowed the company to integrate the stage lighting control via DMX terminals as well as the compressed air measurement with appropriate measurement modules. 

Simtec has developed the closed-loop control technology for this application in-house in C++. Since TwinCAT 3 supports the C++ programming language, Simtec’s entire motion control programming was easily integrated into the TwinCAT 3 automation software and run in real time. The user interface of the Hexaflite® system is another proprietary Simtec solution developed in C++. 

Kinetic Digital Signage

With its Screenflite® system, Simtec has entered a new market. The modular media information system, which weighs 5.3 tons, consists of three circular rotating levels. Each ring holds four LED screens, each with a surface of two square meters, that can be moved approx. 1.1 meters in and out with scissor arms and rotated with or against each other. 

Based on highly dynamic choreography, the LED screens move toward each other and separate again to form various combinations or shapes consisting of two, three, four, or six screens in rapid order. In addition, the flat screens on the upper and lower rings can tilt vertically. The mechanical design ensures that the screens don’t collide with each other. 

On each of the 12 screens, media content can be played in sync with the screens’ motion. Since the motion sequences are determined through programming, sequences in line with the system’s 20 degrees of freedom are possible. The kinetics are freely programmable and can be adapted by the operator’s content designer. “From a control perspective, the digital signage system is our most complex product,” says Christian Spoer.

The greatest challenge lies in the precision of the various motion control speeds and their perfect synchronization. The three rings that move the LED screens via their scissor arms are not linked mechanically but communicate via Wi-Fi using TCP/IP (via ADS). Power and emergency OFF signals are transmitted via slip rings. Each ring uses an ultra-compact C6015 Industrial PC with an Intel Atom® quad-core processor that functions as an EtherCAT master to control the movements of the four screens. Because of their high performance, one of these IPCs can handle the synchronization of all three rings over Wi-Fi. 

The motion control runs in a C++ module with a linked PLC. “We programmed the axis control algorithms and the synchronization of the motion sequences that integrate into TwinCAT 3. The TwinCAT NC library provides the closed-loop controller and profile generator,” adds Christian Spoer. 

To control all 27 PTP axes on the digital signage system’s three levels, one- and two-channel EtherCAT servo drives from the AX5000 series, with integrated safety functionality, are used. To control the smaller motors for rotating the monitors, Simtec uses EL7201 servo terminals with One Cable Technology (OCT) connection because their compact design works perfectly in the limited space available. 

Simtec has used control technology from Beckhoff in multiple projects. The option to employ both centralized and decentralized PC-based control technologies works great for the company and is an important prerequisite for many applications. 

*Images courtesy of Beckhoff. 

For information: 

Beckhoff 

Simtec Group

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