Innovation at it’s best
German Innovation Award for Zimmer Group
Last week, a Modular Transport System was added to the many prizes and awards won by Zimmer Group.
Zimmer Group's Modular Transport System is part of a robot-based, highly flexible, productive and modular manufacturing cell and is used to transport workpieces within the cell. It links the loading and unloading stations with the processing and measuring stations. The individually controlled transport units (shuttles) can be used as master or slave as required, and can operate either individually or in combination. This eliminates the need for a rigid transport connection, such as a continuous conveyor belt.
One decisive advantage over conventional machines is the extremely high system availability of this robotic processing cell. The transport system is designed so that the shuttles can be ejected individually and replaced during operation if necessary. All other system components are designed so that no unnecessary disassembly is required for servicing or maintenance work.
Another innovation of the Modular Transport System is the integrated 48 V battery buffer circuit, which, in combination with the recuperation function of the transport units, reduces the load current peaks by approx. 85% and thus the energy consumption of the system by more than 8%. The cell can be directly connected to an MES system. The individual workpieces are clearly identified by the machine control system using a barcode. This ensures comprehensive production control and high production quality.
The entire system can process variable workpieces in a batch size of 1 and, by adding further function modules, the performance can be scaled almost infinitely. The cells can be expanded from a few meters with 1 or 2 processing stations to 100 meters with more than 30 processing stations. This modularity enables individual solutions that can be put into operation quickly, since each module can be tested individually in advance. This considerably shortens start-up times compared to conventional processing machines. It can be easily adapted to specific applications or to the logistical environment and the necessary safety concepts. This agility in a fully automated environment is currently unmatched by any conservative system on the market!
A digital twin exists for each of these modules, i.e. the software is already available for each module and tested on a HILS system (“Hardware in the Loop System”). If a new combination of modules is required, a digital twin of the entire cell can be generated before the disposition, the material flow can be tested and the performance of the system can be checked in real time. This HILS-based digital twin accompanies the system throughout its entire service life. It serves as a training tool for new operating personnel and for advance testing of new products. In real-time batch size 1 production, the day's production can be simulated in advance, the “production status” can be activated or blocked, thus preventing a production bottleneck.
The central processing module consists of two industrial robots, each equipped with a multi-processing unit. The two cooperating robots work in a spatially limited area. Here, the workpiece is temporarily stopped within an otherwise flowing process. The confined machining space makes it possible to minimize the machining tolerances. Another major challenge is to enable production with an accuracy of +/- 0.1 mm using commercially available robots. To this end, our “Know-How Factory” has developed a sensor-based inline correction function that permanently monitors the required precision and automatically makes corrections if necessary.
