Physik Instrumente (PI) and CyboSoft unveiled what they are calling a revolutionary new capability for the control of ultrasonic piezomotors at SEMICON West in San Francisco. In a close collaboration between these technology leaders, a special implementation of the CyboSoft patented Model-Free Adaptive (MFA) control technology has been engineered to bring plug-and-play closed-loop operation to ultrasonic piezomotors with no servo tuning and with automatic, real-time adaptation to changing loads and motor dynamics.
Performance is optimised and safe in all conditions, equaling or surpassing that of expertly-tuned, configuration-specific conventional servo technology but without sensitive and configuration-specific setup. Uncontrolled oscillation and runaway from mistuning are eliminated. Performance is quiet, smooth and precise.
Ultrasonic piezomotors have tantalised engineers for decades. Their compact size, high speed, responsiveness, non-magnetic nature, vacuum compatibility, sub-micron resolution, in-position stability and energy efficiency held great promise for many demanding applications. They allowed the engineer to eliminate costly and bulky leadscrew and motor-coupling assemblies. And unlike ultra-resolution piezoelectric nanopositioning stacks, their travel was unlimited.
The piezomotor field has enjoyed considerable innovation, and many novel implementations have been introduced, including the patented, high-speed PI-line motors. However, since linear piezomotor dynamics depart in subtle ways from those of common DC servomotors and can vary with usage, they have required sophisticated controllers and knowledgeable setup for best performance. Set up incorrectly or used with an inadequate controller, the motors could be noisy or perform sub-optimally.
The CyboSoft/PI collaboration has yielded a breakthrough in piezomotor control by eliminating the need for intensive servo setup as well as sensitivity to load. The custom MFA Tiger control algorithm developed for PI controllers provides stable, smooth, fast and precise performance from start-up and under all operating conditions.
