Development of a Spherical Air Bearing Positioning System

In line with the general trend of the automation, spherical motion systems are increasingly required in applications such as robot joints, manipulators, orientation control systems, and angular alignment systems. In this paper, a spherical air bearing positioning system (SABS) aiming at providing highly precise rotational motions in two degrees of freedom is designed. The SABS mainly consists of direct-drive voice coil actuators and pneumatic bearing. This paper presents the mechanical structure and control system of the SABS. The model of the SABS is identified based on adaptive control concepts. To eliminate the measurement noise, a noise filter is designed on the basis of the model. Then, an observer-based PID controller is designed and implemented on a dSPACE development card. The experiment results show that the designed controller can achieve higher precision and better tracking performance of about ten times compared to that from a traditional PID controller.

[1]  Hejun Du,et al.  Design of a novel ultrasonic spherical motor , 2000, 2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121).

[2]  Zhi Zhou,et al.  Real-time motion control of a multi-degree-of-freedom variable reluctance spherical motor , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[3]  Liang Yan,et al.  Motion generation methodology of a permanent magnet spherical actuator , 2009, 2009 IEEE/ASME International Conference on Advanced Intelligent Mechatronics.

[4]  Jana L. Schwartz,et al.  AAS 04-122 SYSTEM IDENTIFICATION OF A SPHERICAL AIR-BEARING SPACECRAFT SIMULATOR , 2004 .

[5]  Stuart T. Smith,et al.  Design and control for an electromagnetically driven X–Y–θ stage , 2002 .

[6]  Kok Kiong Tan,et al.  Problem and solution of designing an air bearing system , 2010, 2010 2nd International Conference on Industrial and Information Systems.

[7]  Liang Yan,et al.  Torque modeling of a permanent magnet spherical actuator based on magnetic dipole moment principle , 2008, 2008 IEEE/ASME International Conference on Advanced Intelligent Mechatronics.

[8]  Kok-Meng Lee,et al.  Design concept development of a spherical stepper for robotic applications , 1991, IEEE Trans. Robotics Autom..

[9]  Kyong Sei Lee,et al.  Design of air bearing system for fine motion application of multi-DOF spherical actuators , 1999, 1999 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (Cat. No.99TH8399).

[10]  D.H. Yeom,et al.  Digital controller of novel Voice Coil Motor Actuator for Optical Image Stabilizer , 2007, 2007 International Conference on Control, Automation and Systems.

[11]  Kuang-Chao Fan,et al.  Development of a multiple-microhole aerostatic air bearing system , 2002 .

[12]  Kok-Meng Lee,et al.  Open-Loop Controller Design and Dynamic Characteristics of a Spherical Wheel Motor , 2010, IEEE Transactions on Industrial Electronics.

[13]  Kok-Meng Lee,et al.  Concept Development and Design of a Spherical Wheel Motor (SWM) , 2005, Proceedings of the 2005 IEEE International Conference on Robotics and Automation.

[14]  Liang Yan,et al.  Design and Analysis of a Permanent Magnet Spherical Actuator , 2008 .

[15]  Liang Yan,et al.  Empirical formulation of torque output for spherical actuators with low-cost rotor poles , 2009, 2009 IEEE/ASME International Conference on Advanced Intelligent Mechatronics.

[16]  Kok-Meng Lee,et al.  Development of a spherical stepper wrist motor , 1988, Proceedings. 1988 IEEE International Conference on Robotics and Automation.

[17]  Changliang Xia,et al.  A Neural-Network-Identifier and Fuzzy-Controller-Based Algorithm for Dynamic Decoupling Control of Permanent-Magnet Spherical Motor , 2010, IEEE Transactions on Industrial Electronics.

[18]  Akio Gofuku,et al.  Development of a spherical motor driven by electro-magnets , 2010 .

[19]  Min Hu,et al.  A piezoelectric spherical motor with two degree-of-freedom , 2001 .

[20]  Guoxiao Guo,et al.  Performance analysis of air bearing in a micro system , 2006 .

[21]  Joachim Heinzl,et al.  Control approaches for high-precision machine tools with air bearings , 1999, IEEE Trans. Ind. Electron..

[22]  Jun Liu,et al.  Torque modeling and control algorithm of a permanent magnetic spherical motor , 2009, 2009 International Conference on Electrical Machines and Systems.

[23]  Dae-Gab Gweon,et al.  A new 3-DOF Z-tilts micropositioning system using electromagnetic actuators and air bearings , 2000 .

[24]  Kwang-Yeol Kim,et al.  Robust design of a novel three-axis fine stage for precision positioning in lithography , 2010 .