It looks a bit surreal when you shoot a dart at the high-tech dartboard at TU Wien: The dartboard dashes silently across the wall, rotating in exactly the right way so that it is hit by the dart at the desired point. Everyone who manages to shoot the dart roughly into the right direction is guaranteed to achieve a result that will make even the world’s darts elite jealous.
This is made possible by an innovative system of cable pulls, image recognition and high-precision control. Several cameras record the flight path of the dart, within microseconds the point of impact is calculated. High precision turns of the cable winches, controlled by a sophisticated mathematical model, make the dartboard move and rotate, directing it to the right place. All of this takes only about 250 milliseconds.
A novel cable-driven robot design
"Dart is an excellent use case to demonstrate the performance of our newly developed cable-driven robot," says Prof. Andreas Kugi from the Automation and Control Institute (ACIN) at TU Wien. Georg Feiler, Michael Schwegel and Ulrich Knechtelsdorfer, three members of Kugi's team, are the main people responsible for the dartboard and its sophisticated control system. "The cable-driven robot enables highly dynamic movements, in particular also rotations, which, in previous designs have only been possible with a great deal of additional design work," explains Kugi.
The video (see below) demonstrates the precision of the new technology: Three different people hit the Triple-20 fifteen times in a row - even the world's leading top professionals can hardly manage that. (The triple-20 is the maximum score you can get in darts - in contrast to archery, for example, where you want to hit exactly the middle).
Flexible cables instead of rigid rods
"It would be much more complicated with rigid connections than with the lightweight flexible cables," says Andreas Kugi. His team first had to carry out elaborate mathematical analyses of how the highly dynamic control of the dartboard could be achieved as quickly and precisely as possible - and this mathematical model then had to be combined with control and image recognition algorithms and implemented in an experimental device.
"What I particularly like is that our dartboard shows that today's possibilities of automation allow you to think of processes in a completely new way - why throw precisely when you can also position the board precisely?" says Andreas Kugi. "If you approach such tasks with a bit of creativity, then amazing technological solutions can be implemented that you might hardly have thought possible at the beginning."
Prof. Andreas Kugi
Automation and Control Institute (ACIN)
+43 1 58801 37614