Time grating linear displacement sensor based on alternating light fields

Abstract

The invention discloses a time grating linear displacement sensor based on alternating light fields. The sensor comprises a static pole plate and a moving pole plate, wherein each of the upper and low portions of the static pole plate includes a row of uniformly-distributed square transparent surfaces of the static pole plate, each of the rear upper and lower portions of the static pole plate is equipped with a set of luminescent devices, each of the upper and lower portions of the moving pole plate includes two semi-sinusoid transparent surfaces of the moving pole plate, four photosensitive reception units are fixed on the moving pole plate, and the transparent surfaces of the moving pole plate are covered with photoelectric reception surfaces of the photosensitive reception units. The two sets of the luminescent devices respectively provide alternating light fields, the moving pole plate moves relative to the static pole plate, the four photosensitive reception units output electric signals, two light-field coupling signals are obtained after differencing, a path of travelling wave signals Uo is synthesized via an addition circuit, the path of travelling wave signals Uo is shaped and phase-compared with a path of reference signals Ur, and the linear displacement value of the moving pole plate relative to the static pole plate is obtained via clock interpolation and scale conversion. The time grating linear displacement sensor based on alternating light fields is high in precision, low in power consumption, low in cost and easy to install and prepare.

Description

technical field [0001] The invention relates to a sensor, in particular to a sensor for precision linear displacement measurement in the optical field. Background technique [0002] In the field of optics, the sensing technologies used for precision linear displacement measurement mainly include: grating and laser interferometer. [0003] Gratings measure displacement by counting the number of moiré fringes. It adopts precision mechanical subdivision technology to process very dense and equally spaced grating lines on the surface of the indicator grating and scale grating, and stacks the indicator grating and scale grating together, leaving an appropriate small gap in the middle, and making the two gratings Keep a small angle between the reticle lines, the reticle lines of the two gratings intersect, and irradiate with a light source of constant light intensity in the vertical direction of many intersecting reticle lines, and the light passes through the gap where the retic...

AI Technical Summary

Problems solved by technology

The magnetic field time grating adopts the principle of electromagnetic induction for measurement. Due to the poor machinability of the magnetic permeable material, the production process needs to be wound, so its production efficiency is low. In addition, it requires a large excitation power to drive the stator coil, resulting in high power consumption. Big

The electric field time grating adopts the principle of alternating electric field coupling for measurement. For example, the patent with the announcement number CN102288100B and the name "A time grating linear displacement sensor based on alternating electric field" adopts semiconductor processing technology and has high manufacturing accuracy and consistency. Good, but because the electric field signal is in a divergent state in the air gap, and it requires the parallel installation distance between the fixed-length substrate and the probe substrate to be as small as possible, the installation and production of the sensor are difficult

Images