Design and Realization of a Three Degrees of Freedom Displacement Measurement System Composed of Hall Sensors Based on Magnetic Field Fitting by an Elliptic Function

Sensors

Bo Zhao²  Lei Wang¹  Jiu-Bin Tan² 

[1] Harbin Institute of Technology, D-403 Science Park, No. 2 Yikuang Street, Harbin 150080, China;

关键词: Hall sensor;    displacement measurement;    magnetic field fitting;    elliptic function;   

DOI  :  10.3390/s150922530

来源: mdpi

【 摘 要 】

This paper presents the design and realization of a three degrees of freedom (DOFs) displacement measurement system composed of Hall sensors, which is built for the XYθz displacement measurement of the short stroke stage of the reticle stage of lithography. The measurement system consists of three pairs of permanent magnets mounted on the same plane on the short stroke stage along the Y, Y, X directions, and three single axis Hall sensors correspondingly mounted on the frame of the reticle stage. The emphasis is placed on the decoupling and magnetic field fitting of the three DOFs measurement system. The model of the measurement system is illustrated, and the XY positions and θ_Z rotation of the short stroke stage can be obtained by decoupling the sensor outputs. A magnetic field fitting by an elliptic function-based compensation method is proposed. The practical field intensity of a permanent magnet at a certain plane height can be substituted for the output voltage of a Hall sensors, which can be expressed by the elliptic function through experimental data as the crucial issue to calculate the three DOFs displacement. Experimental results of the Hall sensor displacement measurement system are presented to validate the proposed three DOFs measurement system.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.