A linear hall effect displacement sensor using a stationary two-pair coil system

In this work, a linear position sensor based on a Hall Effect element with electromagnetic coils for measuring long displacement is presented. This paper proposes a novel stationary system using one pair of Helmholtz coils and one pair of Maxwell coils. The Maxwell coil pair is chose to generate uniform gradient magnetic flux intensity. The Helmholtz coil pair is used to increase the magnetic field without sacrificing linearity for reducing the measurement error near the center. Then, a computation of the quasi-static electromagnetic field of the sensor using the finite element method has been performed. Secondary model has been created on the basis of finite element results. Then this model has been optimized with respect to two criteria: linearity and sensitivity. The designed electromagnetic coils pair combining with a Hall sensor has the advantage of displacement measurement with wider range, lower cost and simple structure.

[1]  A. Affanni,et al.  Design and characterization of magnetostrictive linear displacement sensors , 2004, Proceedings of the 21st IEEE Instrumentation and Measurement Technology Conference (IEEE Cat. No.04CH37510).

[2]  C. Schott,et al.  A new two-axis magnetic position sensor , 2002, Proceedings of IEEE Sensors.

[3]  Sukho Park,et al.  Two-dimensional locomotion of a microrobot with a novel stationary electromagnetic actuation system , 2009 .

[4]  D. N. Lyon.  Assembling Conductors: Solenoid Magnet Design . The Magnetic and Mechanical Aspects of Resistive and Superconducting Systems. D. Bruce Montgomery. Interscience (Wiley), New York, 1969. xvi + 312 pp., illus. $13.95. , 1970, Science.

[5]  A. Bruno Frazier,et al.  Linear magnetic position sensor for automotive applications , 1999, Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components.

[6]  A. B. Frazier,et al.  Miniaturized linear magnetic position sensors for automotive applications , 2002, Proceedings of IEEE Sensors.

[7]  D. Marioli,et al.  Contactless electromagnetic excitation of resonant sensors made of conductive miniaturized structures , 2008 .

[8]  Sylvain Martel,et al.  Magnetic microparticle steering within the constraints of an MRI system: proof of concept of a novel targeting approach , 2007, Biomedical microdevices.

[9]  Ulrich Teubner,et al.  Miniaturised optical displacement sensor , 2004, SPIE Photonics Europe.

[10]  J. Genossar,et al.  A tilted‐plate capacitance displacement sensor , 1990 .