The rotary positioner U-651 from PI features a number of innovative solutions. It is driven by several direct drive ultrasonic motors. The very low inertia (moved mass) has a positive effect on the start/stop behavior and velocity control. The table has the potential to reach a maximum speed of 720°/s and also run at very low velocities with a highly constant speed.
The positioner does not have gears, thus preventing backlash or friction and the motors operate on a non-magnetic principle. Hence it is possible to achieve precise bidirectional speed and position control, which is critical for high speed motion contouring. These features enable the M-660 to outperform the stability, acceleration and settling speed of traditional servo motor direct drives and gear-driven mechanisms.
A special motion controller for piezo motors is present to leverage the specific motion characteristics of ultrasonic ceramic motors. Software and driver package (LabView, Matlab, etc) for seamless integration are also included.
The salient features of the precision rotary positioner are:
- Exhibits superior stability, acceleration and settling behavior when compared to traditional rotary tables
- Very low profile of 14 mm
- Self-breaking ceramic direct-drive motors
- Energy saving design, no power consumption at rest, very high position stability
- Precision encoder provides 4 micro radian (0.00023°) resolution
- Vacuum-compatible and non-magnetic ultrasonic motor working principle