Research on fusion measurement technology of capacitive displacement transducer and grating

Abstract

The design techniques of actuating signal source in capacitive displacement transducer measurement system is used for designing a group of multiphase modulation signal source, which generates the multiphase linear light source actuating signal for grating measurement system, after the emitted multiphase modulating light signal is modulated by a scale grating, it is received by a photoelectric component and a compound electrical signal is obtained. Another electrical signal is obtained after processed by circuit, whose frequency is same as the fundamental frequency of actuating signal source, the movement distance x of scale grating can be obtained by detecting the change of phase difference between two electrical signals. Sub-micron or nanometer-level measurement resolution is reached by organically integrating the capacitive displacement transducer and grating measurement technology, by increasing the subdivision number of phase detecting circuit, and by decreasing the point distance of linear light source.