Heavy-duty cable robot

The igus products are used in the parallel cable robot IPAnema 3. The support structure of IPAnema 3 consists of a metal frame structure, but a suitable building structure can also serve as a frame structure for the cable robot. Compact winch units with servo motors and eight synthetic fibre or steel ropes are also available. The ropes are connected to the mobile platform of the rope robot. By changing the rope lengths using the rope winches, the platform can be moved in space in all six degrees of freedom. In the application presented here, the platform is equipped with a pallet gripper as end effector for use in intralogistics. This makes it possible to move and position pallets in all six degrees of freedom in space.
Cable robots, such as those developed by the Fraunhofer Institute for Manufacturing Engineering and Automation IPA for several years, are an innovative solution for automated handling and machining tasks and combine technologies from robotics and crane technology. They are particularly suitable for large working areas or heavy loads. The IPAnema 3 has an installation space of 16 x 11 x 6 metres and a load capacity of up to 250 kilograms.
 
Company: Fraunhofer Institut für Produktionstechnik und Automatisierung IPA
Contact person: Mr. Johannes Stoll
Country: Germany
 

Problem

The end effectors of a rope robot must be supplied with energy, data and media. In the case of the pallet gripper described above, the aim is to supply it appropriately with power, EtherCAT and compressed air.
In another project (project HINDCON3D), however, an end effector was used for 3D concrete printing. For the supply of concrete it was only equipped with a tank for concrete on the platform and thus had a limited printing volume. For a continuous supply of concrete to the 3D printer head, the use of an igus tri-spool would be a possible solution. This would allow volumetrically unlimited printing of concrete.
A cable robot application already received the igus vector award in 2014. Here, however, there was a "standard" structure that used an energy chain and an e-spool. The cable robot mainly moved in two dimensions.
The current IPAnema 3, however, can move in six dimensions. The challenge here is to carry along the supply cables, which must follow in all spatial directions and orientations.
 

Solution

To meet this challenge, IPAnema 3 uses a combination of the 3D energy chain (triflex) to guide the data and supply cables spatially and an e-spool to roll the chain up and down. This combination of triflex and e-spool is called tri-spool.
The e-spool was designed in such a way that it matches the triflex, which is usually not the general rule. This tri-spool is a special prototype development. It has a drum diameter of about two metres and an extension length of about eleven metres. The triflex energy chain can be rolled up and down at a maximum speed of one metre per second. It contains the following cables: one Ethernet/CAT7, a pneumatic hose with an outer diameter of 10 millimetres and two control cables with 5 x 2.5 mm² and 12 x 0.5 mm².
To guide the energy chain, a trough system with deflection unit was also designed. Thanks to the trough system, the e-spool can be easily installed on the floor and does not need to be mounted on the ceiling.