Testing and Qualifying Positioning Systems for Multi-Ton Loads
The nano- and micro world is not limited to microscopic loads. Optics in astronomical telescopes and semiconductor lithography equipment are getting larger and heavier, while alignment tolerances that need to be met are getting tighter. Hexapod parallel-kinematic motion and positioning systems are often used in multi-axis alignment processes, from miniaturized fiber optics to giant telescope mirrors, due to their extreme versatility with randomized pivot point capability and standard 6-degree-of-freedom flexibility.
In addition to the optics industry, many automation processes from precision manufacturing to automotive engineering are also relying on hexapods.
A recent addition, PI’s high load test and assembly hall is equipped with everything to build, test, and verify the performance of each part, with the precision of laser interferometers.
Three gantry cranes span the working area and lift and transport the components of the positioning systems.
A precision ground granite slab with a flatness of 3.8 µm acts as assembly area. Air-cushioning elements decouple the granite slab against external vibration – a great advantage when aligning components of a positioning system during assembly. A second precision ground granite slab is employed as a measuring plane.
Customers often request qualification data of their high load positioning equipment, mounted at the exact angle with the exact payload as planned in their applications. A giant lift and rotary platform, along with interferometers, are used for these tests.
The rotary and lift test platform allows infinite rotation of payloads to 10 tons around 360°. Hexapod positioning systems can be tested in the exact orientation as in the customer’s final installation. Metrology equipment such as laser interferometers and motion systems are mounted on the same test platform, to avoid relative positioning errors.