DocumentCode :
1395691
Title :
Nanometer positioning of a linear motion stage under static loads
Author :
Awaddy, B.A. ; Shih, Wu-Chu ; Auslander, David M.
Author_Institution :
Dept. of Mech. Eng., California Univ., Berkeley, CA, USA
Volume :
3
Issue :
2
fYear :
1998
fDate :
6/1/1998 12:00:00 AM
Firstpage :
113
Lastpage :
119
Abstract :
A standard lead-screw-driven linear translation table was fitted with a secondary voice coil actuator, which can apply forces of ±0.5 N on the translating stage. The DC servomotor-driven lead screw is capable of positioning the table to a nominal precision of ±0.5 μm. The secondary actuator then positions the table to ±1 mm. Both actuators utilize closed-loop feedback algorithms. This configuration has significant advantages over the more common “piggyback” arrangement, which often uses piezoelectric actuators. The advantages include preservation of the original load surface and position sensors and an easier to control actuator. Its ability to operate under static load and a model of the microdynamic behavior are addressed in this paper. When static loads of up to 36 N were applied to the translating stage, the secondary actuator could still displace the table to ±500 nm and control the position down to its zero-load precision. The microdynamic behavior in this region is nonlinear and was modeled using the modified Dahl model of friction. The key parameters in the model were identified using a 2 Hz sinusoidal input force with varying amplitudes from the secondary actuator. For a constant loading force, the parameters did not vary significantly with different excitation forces. The friction parameter relating the initial slope of the friction force versus displacement curve did change with different loading forces. Also, for smaller input signals causing displacements of less than 200 nm, the friction parameters would tend to drift, depending on input magnitudes
Keywords :
closed loop systems; feedback; friction; motion control; position control; 2 Hz sinusoidal input force; DC servomotor-driven lead screw; closed-loop feedback algorithms; lead-screw-driven linear translation table; linear motion stage; microdynamic behavior; modified Dahl model; nanometer positioning; static loads; voice coil actuator; Coils; Dynamic range; Fasteners; Feedback; Friction; Hydraulic actuators; Mechanical engineering; Motion control; Piezoelectric actuators; Position control;
fLanguage :
English
Journal_Title :
Mechatronics, IEEE/ASME Transactions on
Publisher :
ieee
ISSN :
1083-4435
Type :
jour
DOI :
10.1109/3516.686679
Filename :
686679
Link To Document :
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