Magic carpet for transporting components

A highly flexible transport system with precise and highly dynamic positioning is made possible by planar movers or plates that levitate freely above arbitrarily arranged planar tiles. This gives the plates an unprecedented freedom in two-dimensional motion, while avoiding any friction and without direct contact with the surface. The contact-free mover travel also eliminates wear, emissions and the carryover of contamination.

The free choice of surfaces – easy-to-clean glass, stainless steel in hygienic design or plastic film – enables use in the clean room, in the pharmaceutical and food industries, and in a vacuum.

The system features sealed, watertight and chemically resistant tiles which house flat coils and all of the electronics needed to detect and control the movers, which levitate above them, this made possible by integrated permanent magnets. The tiles measure 240 x 240mm and can be arranged in any desired geometries that relate to the application. The movers can be moved jerk-free and contact-free in two dimensions at up to 4m/s with 2g acceleration and 50μm positioning repeatability. The movers are silent and move smoothly without abrasion.

Path optimisation

The tiles are linked via Beckhoff’s new 1Gbit/s version of EtherCat (EtherCat G) to a PC-based controller. Using Beckjhoff's TwinCAT software, the controller synchronises the motion of the movers, ensuring that they do not collide. It also optimises their paths automatically and can link groups of movers to handle heavier loads. The movers can be used not only horizontally, but also vertically and even upside down (although a power failure can be embarrassing if used upside down!).

The planar motor system is highly scalable to suit individual needs and considerably simplifies the design of machines and plants. Due to the maximum flexibility in mover positioning and the very high dynamics it is possible, for example, to divide product flows very simply and individually, so that robots or inflexible mechanical devices which were previously necessary can be replaced.

As well as moving freely in X and Y directions, the levitating movers exhibit further motion functions:
- lifting and lowering by up to 5mm, optionally including a weighing function
- tilting by up to 5° for transporting and handling liquids without spilling them
- rotation by up to 15° (or up to 360° above special planar tiles).

There is a choice of four different planar mover types:
- 95 x 95mm small mover for payloads of up to 0.4kg
- 155 x 155mm standard mover for payloads of up to 1.5kg
- 155 x 275mm long mover for asymmetric payloads of up to 3kg, particularly suitable for travelling along walls
- 275 x 275mm big mover for payloads of up to 6kg

Starter kits are also available so that potential customers can trial system in their own environments