Multi-axis Parallel-Kinematic Motion Systems with a Large Dynamic Range

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

The objective of this award is to create a machine design methodology that simultaneously enables large motion range (10 millimeter) and nanometric precision in multi-axis, flexure-based motion systems. The research approach will include the use of constraint-based design methods to conceive novel parallel-kinematic physical architectures that inherently take into account the geometric constraints and limitations associated with flexure bearings, actuators and sensors. Innovations in dual-winding voice coil actuation and complementary sensing will be employed to overcome the traditional signal to noise and distortion ratio limits in these components. Feedback control schemes that address the unique challenges associated with large dynamic range, such as non-linear behavior, non-collocated sensing and actuation, and noise and disturbance sensitivity, will be investigated and implemented. A concurrent optimization of the physical and control systems will be conducted to meet the targeted performance in flexure-based motion systems. Even though existing flexure-based motion systems are inherently capable of high precision, their small motion range (approximately 100 microns per axis) restricts several applications including scanning probe microscopy, nanometrology and direct-write lithography. The proposed large-range, high-precision motion systems, when incorporated within scanning probe microscopy techniques, will enable seamless imaging of large areas (10 by 10 millimeters) without any stitching errors, while maintaining nanometric image resolution. This will extend the use of such imaging techniques in practical industrial settings, for example, inspection and process control in semiconductor, LCD flat-panel, and magnetic disk-drive fabrication industries. The proposed motion systems will also serve the field of nanometrology by enabling the creation of coordinate measuring machines with nanometric uncertainty. The educational outreach in this project will be carried out via professional tutorials on high precision motion systems offered at engineering conferences, graduate and undergraduate level curriculum development, and a new exhibit at the local science museum for K-12 children.