|
CHEN Xuedong
YU Xianzhong
HE Xueming
State Key Laboratory of Digital Manufacturing Equipment &
Technology,
Huazhong University of Science and
Technology,
Wuhan 430074, China
YAN Tianhong
National Optical Lithography Equipment
R & D Center,
Shanghai 201203, China
|
|
|
DYNAMIC CHARACTERISTIC ANALY- SIS OF
PRECISE LONG STROKE LINEAR MOTOR WITH AIR-BEARING IN OPTICAL
LITHOGRAPHY*
Abstract:
Dynamic characteristic is presented by identifying the model and the dynamic parameters of a precise long stroke linear motor (PLSLM) with the air-bearing in optical lithography. The PLSLM is supported by air-bearing on the stator, and is driven by on-board two large linear motors in a cross-configuration. Firstly, a model of the PLSLM is established by finite element method (FEM). Secondly, based on the model, the natural frequencies and model shapes are discussed. And the contribution of each active mode is evaluated by computing the modal participation factors (MPF), which indicates the major vibration direction. Furthermore, by the experimental modal analysis, the experimental results are in agreement with simulation results, which it is sure that the FEM is reasonable. What’s more, comparing with the effects on the frequency due to the air-bearing stiffness, the relations of the natural frequencies with the air-bearing stiffness are found. It is found that the frequency response curve is fluctuant with the air-bearing stiffness in each direction. Finally, it is conclusion that the natural frequency of the PLSLM is largely affected by the air-bearing stiffness variety. This research is contributed to the dynamic characteristics resulted from the air-bearing stiffness. Further work will include better optimization on the dynamic parameter in the controller design through the control algorithm for the precise long stroke motor.
Key words:
Dynamic analysis Air-bearing stiffness Precise long stroke linear motor
Frequency response
|
|
|
Biographical notes
CHEN Xuedong is a professor in State Key Laboratory of Digital
Manufacturing Equipment & Technology, Huazhong University of Science and
Technology, China. He received his PhD degree from Saga University,
Japan, in 2001. His research interests include robotics, mechanical
dynamics, intelligent robots, and applications of soft computing for
robot control.
Tel: +86-27-87557325, E-mail: chenxd@mail.hust.edu.cn
YU Xianzhong is a PhD candidate in State Key Laboratory of Digital
Manufacturing Equipment & Technology, Huazhong University of Science and
Technology, China. His research interests include mechanical dynamics,
gas-solid coupling.
Tel: +86-27-87557325; E-mail: yxianzhong@163. com
HE Xueming is a PhD candidate in State Key Laboratory of Digital
Manufacturing Equipment & Technology, Huazhong University of Science and
Technology, China. His research interests include air-levitated bearing,
mechanical dynamics, precise positioning and measurement, and controller
design for the precise machine.
Tel: +86-27-87557325; E-mail: hexueming66@163.com
YAN Tianhong is working in National Optical Lithography Equipment R & D
Center. He is also a guest professor of Huazhong University of Science
and Technology. He received his PhD degree in aerospace engineering from
Harbin Institute of Technology, China, in 1999. His research interests
are in applied mechanics, as well as dynamics and vibration, especially
as applied to high-precise mechatronic systems. He has also worked in
numerical analysis in large complex systems.
Tel: +86-21-51315131; E-mail: yanth@21cn.com
References
[1] THORNTON B H, BOGY D B. Head disk
interface dynamic instability due to intermolecular forces[J]. IEEE
Transactions on Magnetics, 2003, 39(5): 2 420-2 422.
[2] DAL H I, KIM C E. Finite element force calculation of a linear
induction motor taking account of the movement[J]. IEEE Transactions on
Magnetics, 1994, 30(5): 3 495-3 498.
[3] KIM J K, JOO S W, HAHN S C. Static characteristics of linear BLDC
motor using equivalent magnetic circuit and finite element method[J].
IEEE Transactions on Magnetics, 2004, 40(2): 742-745.
[4] JANG S M, CHOI J Y, CHO H W, et al. Dynamic characteristic analysis
and experiments of moving-magnet linear actuator with cylindrical
Halbach array[J]. IEEE Transactions on Magnetics, 2005, 41(10): 3 814-3
816.
[5] LU C, TONY R, EASTHAM. Transient and dynamic performance of a linear
induction motor[J]. Industry Applications Society Annual Meeting, 1993,
1: 266-273.
[6] MEKID S. High precise linear slide. Part I: design and
construction[J]. International Journal of Machine Tools & Manufacture,
2000, 40(7): 1 039-1 050.
[7] MEKID S, OLEJNICZAK O. High precise linear slide. Part II: control
and measurement[J]. International Journal of Machine Tools &
Manufacture, 2000, 40(7): 1 051-1 064.
[8] STOUT K J, BARRANS S M. The design of aerostatic bearings for
application to nanometer resolution manufacturing machine systems[J].
Tribology International, 2000, 33(12): 803-809.
[9] LIU C T, HSU S C. Analysis of linear electromagnetic motion devices
by multiple-reference frame theory[J]. IEEE Transaction on Magnetics,
1998, 34(4): 2 063-2 065.
[10] CHEN X D, HE X M. The effect of the recess shape on performance
analysis of the gas-lubricated bearing in optical lithography[J].
Tribology International, 2006, 39: 1 336-1 341.
[11] ZHU Bofang. The principle of the finite element method and
numerical methods[M]. 2nd ed. Beijing: Publishing Company of hydraulic
and electric engineering, 1979. (in Chinese)
|