A total of twelve large moving LED screens are positioned to form moving advertising spaces in various formats and formations. Low-backlash and torsionally rigid planetary gearboxes from Wittenstein alpha are installed.

The low-backlash planetary gearboxes of the TP+ series meet the key requirements of Simtec Systems from Braunschweig, the inventor and manufacturer of the digital signage advertising system. The torsional rigidity of the gearboxes minimizes vibrations even with high dynamic movement and, together with the low torsional backlash, ensures optimum synchronization and positioning accuracy of the individual large LED screens. Added to this is the space-saving design of the gearboxes, which meant that they could be easily integrated into the tight installation spaces of the rotating construction.

Simtec placed the highest demands on the design of the planetary gears for the kinematics with its twelve screens on three ring-shaped rotation levels. As the system is freely programmable and therefore any motion sequences of the 20 degrees of freedom are possible, Simtec created nine different characteristic motion cycles. These formed the basis for dimensioning the individual gears. The Cymex 5 design tool, into which the motion simulations programmed by Simtec were imported, proved its worth here.

A new dimension in attracting attention
The use of digital media content in advertising and information systems such as electronic posters, digital advertising at the point of sale, digital door signage or large-screen projections - digital signage for short - is entering a new era in highly frequented indoor public areas. While static LED or poster advertising only achieves a low level of perception - and therefore rather low sales effects for advertising providers and advertising customers - moving advertising with electronic 3D effects is an eye-catcher with higher earnings potential for all parties involved. Screenflite is the Simtec brand name of the interactive advertising system installed at Rome airport; it guarantees the highest possible attention-grabbing effect because people instinctively look at moving objects. Screenflite makes use of this and turns advertising into an eye-catcher.

Gearbox selection with design software
This construction weighs a considerable ten tons. To drive the kinematics, Simtec wanted to use gearboxes and servo actuators with high output torques and maximum speeds as well as a wide range of ratios in order to achieve high positioning accuracy and highly dynamic cycle operation. TP+ low-backlash planetary gearboxes from the alpha Advanced Line portfolio segment and TPMP+ rotary servo actuators from Wittenstein were the first choice for this. No other gearbox could meet the requirements for this installation size. Thanks to their special helical gearing, the gearboxes are quiet; even at speeds of 3,000 rpm, they are no louder than a conversational noise level, meaning that onlookers in the hall do not hear any movement noise when the ring levels are turned or the scissor arms are extended.

Overall, the interactive structure of the Screenflite with rings and scissor arms offers almost infinite possibilities for combined movements. 17 TP+ gearboxes of different dimensions and three TPMP+ servo actuators are used here. Simtec had created simulations with travel profiles and forces for the nine characteristic movement cycles in this installation. They were imported into the Cymex 5 design tool as ASCII files. The gearboxes and servo drives at Wittenstein were then selected on the basis of the suggestions calculated by the program, which simplified the design and made it reliable.

After delivery and assembly of the individual modules, "Le Chandelier" - as the operator calls the Screenflite - was put into operation and inaugurated in July 2018. Thanks to the TP+ gears, the three rotating rings can be rotated with and against each other as required - dynamically and with high precision. Four LED screens are mounted on each ring, which are extended and retracted by scissor arms with a lifting distance of around 1,100 millimetres. The flat screens on the upper and lower levels can be swiveled vertically. The movement of the scissor arms on one level is mechanically coupled, which prevents imbalances in the rotational movement of the rings. The mechanical design of the kinematics minimizes vibrations and prevents the screens from touching each other; the scissor arms can be retracted precisely to a defined end point.

How the screens ultimately move is determined by the operator's content designer. The flexible motion programming adapts the rotations and horizontal movements individually to the respective media content and desired effects in order to achieve maximum attention and advertising impact and thus reach a larger audience than is possible with stationary forms of advertising. pb