Air-bearing position optimization based on dynamic characteristics of ultra-precision linear stages

Abstract

Air-bearings are installed between the stator and the mover of ultra-precision linear stages to suppress vibration and mechanical contact. Spring-damping elements are used to emulate the complex interaction of the finite element model (FEM) developed in this paper and the system dynamic behaviors are analyzed. Through the experimental modal test, the validity and reliability of the model are proven. However, the dynamic characteristics including mode frequency, mode shape, and response amplitude are obviously changed with the position of air-bearings. The combined optimization method is used to optimize the air-bearings position. The best and worst positions are obtained using the dynamic characteristic analysis. The method can be generalized to the connection position of different components in manufacture elements and to implement the system dynamic characteristics optimization when the connection position can be changed.

References

1. Dal H I, Kim C E . Finite element force calculationof a linear induction motor taking account of the movement. IEEE Transactions on Magnetic, 1994, 30(5): 3495–3498. doi:10.1109/20.312692
2. Kim J K, Joo S W, Hahn S C . Static characteristics of linear BLDC motor using equivalentcircuit and finite element method. IEEETransactions on Magnetic, 2004, 40(2): 742–745. doi:10.1109/TMAG.2004.825033
3. Jang S M, Choi J Y, Cho H W . Dynamic characteristic analysis and experiments of moving-magnetlinear actuator with cylindrical Halbach array. IEEE Transactions on Magnetic, 2005, 41(10): 3814–3816. doi:10.1109/TMAG.2005.854931
4. Lu Changan, Tony R, Eastham. . Transient and dynamics performance of a linear inductionmotor. Industry Application Society AnnualMeeting, 1993, 1: 266–273
5. Stout K J, Barrans S M . The design of aerostaticbearings for application to nanometer resolution manufacturing machinesystems. Tribology International, 2000, 33(12): 803–809. doi:10.1016/S0301-679X(00)00118-3
6. Mekid S . Highprecision linear side. Part I: design and construction. International Journal of Machine Tool & Manufacture, 2000, 40(7): 1039–1050. doi:10.1016/S0890-6955(99)00109-1
7. Mekid S, OlejniczakO. High precision linear side. Part II: control and measurement. International Journal of Machine Tool & Manufacture, 2000, 40(7): 1051–1064. doi:10.1016/S0890-6955(99)00110-8
8. Liu C T, Hsu S C . Analysis of linear electromagneticmotion devices by multiple-reference frame theory. IEEE Transactions on Magnetic, 1998, 34(4): 2063–1341. doi:10.1109/20.706796
9. Dejima S, Gao Wei, Shimizu H, Kiyono S, Tomita Y . Precision positioning of a five degree-of-freedomplanar motion stage. Mechatronics, 2005, 15(8): 969–987. doi:10.1016/j.mechatronics.2005.03.002
10. Chen X D, He X M . The effect of the recessshape on performance analysis of the gas-lubricated bearing in opticallithography. Tribology International, 2006, (39): 1336–1341. doi:10.1016/j.triboint.2005.10.005
11. Khatait J P, Lin W, Lin W . J. Design and development of orifice-type aerostaticthrust bearing. SIMTech technical reports, 2005, 6(1): 7–12