An active air thrust bearing controlled by an Arduino board and digital valves is described. A numerical model for the complete system is developed to design the control and perform a sensitivity analysis based on geometric parameters such as the conductance of the valves. Model validation is based on experimental open-loop and closed-loop tests. The purpose of the model is to determine the range of force and air gap height in which the pad can be controlled.

1. [1] J. Li, K. Tadano, K. Kawashima, T. Fujita, and T. Kagawa, “Trajectory Control of Pneumatic Servo Table with Air Bearing,” Int. J. Automation Technol., Vol.5, No.6, pp. 800-808, 2011.
2. [2] J.-K. Park, S.-K. Ro, B.-S. Kim, W.-C. Shin, and H.-H. Lee, “Precision Component Technologies for Microfactory Systems Developed at KIMM,” Int. J. Automation Technol., Vol.4, No.2, pp. 127-137, 2010.
3. [3] S. Tsujimura, Y. Hashimoto, T. Matsuoka, T. Hirayama, and K. Sasaki, “Pneumatic Servo Bearing Actuator with Multiple Bearing Pads for Ultraprecise Positioning,” Int. J. Automation Technol., Vol.7, No.5, pp. 498-505, 2013.
4. [4] M. R. Bryant and S. A. Velinsky, N. H. Beachley, and F. J. Fronczak, “A Design Methodology for Obtaining Infinite Stiffness in an Aerostatic Thrust Bearing,” J. of Mechanical Design, Vol.108, No.4, pp. 448-453, 1986.
5. [5] P. L. Holster and J. A. H. Jacobs, “Theoretical Analysis and Experimental Verification on the Static Properties of Externally Pressurized Air-Bearing Pads with Load Compensation,” Tribology Int., Vol.20, No.5, pp. 276-289, 1987.
6. [6] K. Sato, K. Yamada, S. Togo, Y. Saito, and K. Unno, “Study on Externally Pressurized Gas Bearings with Infinite Stiffness (2nd Report) – Experiments on the Static Characteristics of a Circular Thrust Bearing –,” J. of the Japan Society for Precision Engineering, Vol.62, No.1, pp. 85-89, 1996.
7. [7] M.-F. Chen and Y.-T. Lin, “Dynamic analysis of the X-shaped groove aerostatic bearings with disk-spring compensator,” JSME Int. J. Series C, Mechanical Systems, Machine Elements and Manufacturing, Vol.45, No.2, pp. 492-501, 2002.
8. [8] T. Raparelli, V. Viktorov, F. Colombo, and L. Lentini, “Aerostatic Thrust Bearings Active Compensation: Critical Review,” Precision Engineering, Vol.44, pp. 1-12, doi:10.1016/j.precisioneng.2015.11.002, 2016.
9. [9] H. Mizumoto, H. Tanaka, K. Okuno, T. Matsubara, and R. Kawakami, “An Infinite-stiffness Aerostatic bearing with an Exhaust-Control Restrictor,” J. of the Japan Society for Precise Engineering, Vol.57, No.11, pp. 2054-2059, 1991.
10. [10] H. Mizumoto and T. Shimizu, “An Infinite-stiffness Aerostatic Spindle with Active Restrictors,” J. of the Japan Society for Precise Engineering, Vol.59, No.4, pp. 607-612, 1993.
11. [11] Y. Sato, K. Maruta, and M. Harada, “Dynamic characteristics of hydrostatic thrust air bearing with actively controlled restrictor,” J. Tribol, Vol.110, No.1, pp. 156-161, 1988.
12. [12] S. Morosi and I. F. Santos, “Active lubrication applied to radial gas journal bearings. Part 1: Modeling,” Tribology Int., Vol.44, No.12, pp. 1949-1958, 2011.
13. [13] H. Aoyama, I. Watanabe, K. Akutsu, and A. Shimokohbe, “An Ultra Precision Straight Motion System (1st Report),” J. of the Japan Society for Precision Engineering, Vol.54, No.3, pp. 558-563, 1988.
14. [14] H. Matsumoto, J. Yamaguchi, H. Aoyama, and A. Shimokohbe, “An Ultra Precision Straight Motion System (2nd Report),” J. of the Japan Society for Precision Engineering, Vol.54, No.10, pp. 1945-1950, 1988.
15. [15] H. Mizumoto, S. Arii, Y. Kami, K. Goto, T. Yamamoto, and M. Kawamoto, “Active inherent restrictor for air-bearing spindles,” Precision Engineering, Vol.19, No.2-3, pp. 141-147, 1996.
16. [16] G. Aguirre, F. Al-Bender, and H. Van Brussel, “Dynamic stiffness compensation with active aerostatic thrust bearings,” Proc. of ISMA 2008, pp. 105-117, 2008.
17. [17] F. Colombo, L. Lentini, T. Raparelli, and V. Viktorov, “Actively compensated aerostatic thrust bearing: design, modelling and experimental validation,” Meccanica, Vol.52, No.15, doi:10.1007/s11012-017-0689-y, 2017.
18. [18] F. Colombo, L. Lentini, T. Raparelli, and V. Viktorov, “Experimental identification of an Aerostatic Thrust Bearing,” Advances in Italian Mechanism Science, pp. 441-448, 2016.
19. [19] H. Mizumoto, Y. Tazoe, T. Hirose, and K. Atoji, “Performance of High-speed precision air-bearing spindle with active aerodynamic bearing,” Int. J. Automation Technol., Vol.9, No.3, pp. 293-302, 2015.
20. [20] K. Y. Huang and Y. C. Shiao, “Design and Development of Magnetostrictive Actuating Restrictor for Aerostatic Thrust Bearing,” Proc. of the 12th IFToMM World Congress, pp. 18-21, 2007.
21. [21] S.-K. Ro, S. Kim, Y. Kwak, and C. H. Park, “A linear air bearing stage with active magnetic preloads for ultraprecise straight motion,” Precision Engineering, Vol.34, No.1, pp. 186-194, 2010.
22. [22] F. Al-Bender and H. Van Brussel, “Active dynamic compensation of aerostatic bearings,” Proc. of the Int. Conf. on Noise and Vibration Engineering, pp. 187-197, 1994.
23. [23] G. Belforte, T. Raparelli, V. Viktorov, and A. Trivella, “Analysis of steady and transient characteristics of pneumatic controlled air bearing,” Proc. of the 5th JFPS Int. Symp. on Fluid Power, Vol.2002, No.5-3, pp. 699-704, 2002.
24. [24] G. Belforte and T. Raparelli, “Development of a new actively compensated pneumatic journal bearing,” Proc. of 4th Scandinavian Int. Conf. on Fluid Power, pp. 493-503, 1995.
25. [25] F. Colombo, D. Ghodsiyeh, T. Raparelli, A. Trivella, and V. Viktorov, “Theoretical and experimental study of a rectangular grooved air pad,” Advances in Italian Mechanism Science, pp. 431-439, 2016.
26. [26] F. Colombo, D. Maffiodo, and T. Raparelli, “Active Gas Thrust Bearing With Embedded Digital Valves and Backpressure Sensors,” Tribology Trans., Vol.60, No.5, pp. 807-813, doi:10.1080/10402004.2016.1213344, 2017.
27. [27] D. Maffiodo, F. Colombo, and T. Raparelli, “Open and closed loop control of an active air bearing with digital valves,” Proc. of the XXIII Conf. of the Italian Association of Theoretical and Applied Mechanics, 2017.
28. [28] G. Belforte, F. Colombo, T. Raparelli, A. Trivella, and V. Viktorov, “Study of the static and dynamic performance of rectangular air pads by means of lumped parameters models,” Proc. of the 11th Biennial conference on Engineering Systems Design and Analysis ESDA 2012, 2012.
29. [29] F. Colombo, T. Raparelli, A. Trivella, and V. Viktorov, “Lumped parameters models of rectangular pneumatic pads: static analysis,” Precision Engineering, Vol.42, pp. 283-293, 2015.
30. [30] G. Belforte, F. Colombo, T. Raparelli, A. Trivella, and V. Viktorov, “Experimental Analysis of Air Pads with Micro Holes,” Tribology Trans., Vol.56, No.2, pp. 169-177, 2013.
31. [31] D. Maffiodo and T. Raparelli, “Three-Fingered Gripper with Flexure Hinges Actuated by Shape Memory Alloy Wires,” Int. J. Automation Technol., Vol.11, No.3, pp. 355-360, 2017.
32. [32] D. Maffiodo and T. Raparelli, “Resistance feedback of a shape memory alloy wire,” Advances in Robot Design and Intelligent Control, pp. 97-104, doi:10.1007/978-3-319-21290-6_10, 2016.