Patent ID: 7349099
Filing Date: 2008-03-25
Classification: G01B,G01D

Abstract:
1. A method for measuring the position of a measurement object in association with a fiber optic interferometric position sensor to measure the position of said measurement object, comprising: providing a fiber optic interferometric position sensor and a measurement object, said fiber optic interferometric position sensor fiber optic interferometric position sensor being constituted by two fiber optic interferometers; obtaining a first initial signal and a second initial signal from the position of said measurement object measured by means of said fiber optic interferometric position sensor; adjusting the phase difference between said first initial signal and said second initial signal so as to alter said first initial signal and said second initial signal to form a third initial signal and a fourth initial signal which have a 90-degree phase difference; moving said measurement object to change the position of said measurement object so that said two fiber optic interferometers of said fiber optic interferometric position sensor output a first measurement signal and a second measurement signal corresponding to the position of said measurement object; computing the values of biases of said first measurement signal and said second measurement signal, respectively, both of which being corrected by a bias correction method to obtain a third measurement signal and a fourth measurement signal; obtaining a phase value corresponding to the position of said measurement object from said third measurement signal and said fourth measurement signal after calculation by an interpolation technique; and obtaining the position of said measurement object after computation by using said phase value.