Synthesis and analysis of parallel Kinematic XY flexure mechanisms

This thesis presents a family of XY flexure mechanisms with large ranges of motion, first-order decoupled degrees of freedom, and small parasitic error motions. Synthesis is based on an systematic and symmetric layout of constraints that are realized by means of common flexure building blocks. An analytical formulation incorporating geometric non-linearities is used in deriving the characteristics of these flexure building blocks. Of concern are issues related to qualification and quantification of undesirable motions, mobility, stiffness variation within the range of motion, determination of center of stiffness, and sensitivity to manufacturing and assembly tolerances. Based on the properties of the building blocks, the performances characteristics of the resulting XY flexure mechanisms are discussed and the influence of symmetry in reducing error motions is analytically illustrated. To verify the design theory, a 300mm x 300mm prototype stage was fabricated, assembled and tested at the National Institute of Standards and Technology (NIST). Measurements using laser interferometry, autocollimation and capacitance gauges indicate levels of performance much better than the capabilities of the current state of the art of precision flexure stages. The prototype flexure stage has a 5mm x 5mm range of motion, with cross-axis errors of the order of one part in one thousand, and motion stage yaw errors of the order of a few arc seconds.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Awtar, Shorya, 1977-

Advisor dc:contributor.advisor

• Alexander H. Slocum.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/17945

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/17945