A project led by the Max Planck Institute for Biological Cybernetics (MPI) in Tübingen and the Fraunhofer IPA has co-developed a new cable-driven parallel robot. The is a first for transporting humans while at the same time setting new standards in terms of workspace, acceleration and as a payload motion simulator. The project has thus succeeded in decisively advancing a technology previously used for automation solutions in the field of intra-logistics, that is in applications where optimising, automating, integrating, and managing the logistical flow of material goods is important.
To date, cable robots have been used in production environments, where they meet high requirements. The system is almost double the capacity of conventional industrial robots in terms of size and pay-load.
In the cable-driven simulator, the motion of the cabin is controlled by eight unsupported steel cables attached to winches. In contrast to conventional motion simulators, the use of cables makes it possible to reduce the moving mass and to scale the workspace to any required size. A total drive power of 348 kW allows the cabin to accelerate at 1.5 times gravitational acceleration along freely programmable paths inside a workspace of 5m x 8m x 5m. In addition, the cables can be reattached in under an hour to enable the simulator to be adapted to different cabins and thus used for a range of scenarios.
During the two-year collaboration between both Institutes have not only implemented the control algorithms, but also developed a lightweight yet rugged carbon fibre cabin capable of withstanding the high dynamic loads during operation. Made entirely from carbon fibre tubes, the cabin frame maximises the usable cabin volume with a diameter of 260 cm for projection surfaces and cockpit instrumentation. This allows it to be used for high quality video projections and realistic operator interfaces. At the same time, the light 80kg frame is capable of accelerating at high speed while also withstanding high forces because during operation the cables pull on the outer structure with up to 1.5 tonnes.
Its large workspace and dynamic capabilities make the simulator suitable for a wide spectrum of VR (virtual reality) applications, including driving/flight simulation as well as investigation of basic perception processes in humans.
“This simulator offers us entirely new possibilities for studying motion perception with possible applications in neurological research into balance disorders,” says Dr. Heinrich Bülthoff, lead professor from MPI, who is a long-time perception researcher.
There is a history of collaboration between the Fraunhofer and Max Planck Institutes which is common in Germany, combining basic research and industry-oriented technology to develop innovative products.