Precision positioning systems from PI
03 April 2015
New from Physik Instrumente is the Q-545 precision linear positioning stage based on compact, piezoelectric inertia drives, and the H-860KMAG high-dynamics hexapod that uses magnetic direct drives.

Q-545
The compact Q-545 offers precise positioning for 13mm and 26mm travel ranges, and is based on compact, piezoelectric inertia drives. Just 45mm wide, the Q-545 combines high forces, high velocity and high positioning accuracy that cannot be achieved using conventional drive principles, such as dc or stepper motors in a similar form factor.
The holding force and the maximum feed force are both 8N, the maximum velocity is 10mm/s. Since the piezomotor is self-locking at rest, it requires no current and generates no heat.
The compact installation space in the Q-545 contains precision components such as crossed roller guides with forced cage control which allow a high travel accuracy of ±50µrad with a 13mm travel range.
For closed-loop operation, the linear stage is equipped with an optical linear encoder that achieves a resolution of 1 nm. Like the motor, the linear scale is arranged centrally between the guides. This facilitates parallax-free position measurements. Combined with the piezoelectric inertia drive, minimal incremental motion of just a few nanometres can be achieved reliably and repeatedly.
Position control, designed for rapid point-to-point motion, is handled by the E-871 motion controller.

H-860KMAG
The Q-545 series is also available as a vacuum-compatible version.
Also new from PI are parallel kinematic Hexapod systems with magnetic direct drives. They offer extremely high dynamics and are intended for motion simulations and test equipment in industry and research.
The H-860KMAG is based on the PIMag Voice Coil magnetic drives also developed by PI. The special design with flexure joints and contact-free magnetic drive principle has neither frictional nor rolling parts for guides and joints. It allows for zero-play positioning without mechanical noise in the drive train.
An integrated linear encoder ensures reliable position control and repeatable accuracy. Operating frequencies of >100 Hz are possible for small strokes, while velocities of several hundred mm/s and accelerations of up to 4g can be achieved.
The reference-class 6-axis system has a parallel kinematic structure for six degrees of freedom and offers precise tracking of pre-defined trajectories, sinusoidal curves and freely definable paths with high trajectory accuracy. This also includes a powerful digital controller with open software architecture and Hexapod-specific software.
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