Device and method for measuring gas film gap of dynamic pressure motor on basis of simultaneous phase shifting interferometry

Abstract

The invention discloses a device and method for measuring a gas film gap of a dynamic pressure motor on the basis of the simultaneous phase shifting interferometry and relates to a device and method for measuring the gas film gap of the dynamic pressure motor. The invention solves the problems of a short measurement working distance of a capacitive sensor and limitation to measurement accuracy of a laser triangular sensor currently. The device disclosed by the invention mainly comprises an interference system, an orthogonal grating light splitting and phase shifting device and an image acquisition system; and the device respectively uses a round light spot and a strip light spot as axial / radial measurement light spots, adopts an orthogonal Ronchi grating to implement light splitting, adopts a four-quadrant polarizer to implement phase shifting and adopts a CCD (Charge Coupled Device) to carry out image acquisition. According to the scheme adopted by the invention, a probe of the device is vertically fixed at a certain distance relative to an axial / radial measurement plane of the dynamic pressure motor to be measured; and the simultaneous phase shifting interferometry principle, the grating diffraction light splitting principle, the polarization phase shifting characteristic and the image acquisition principle are utilized to measure axial and radial displacement change values corresponding to stiffness variation of a gas film of the dynamic pressure motor. The device has high stability and common-path, large-working-distance high-resolution measurement can be implemented.

Description

technical field [0001] The invention relates to a device and method for measuring air film gap of a dynamic pressure motor, in particular to a device and method for measuring air film gap of a dynamic pressure motor based on synchronous phase-shifting interference, and belongs to the technical field of optical detection and measurement. Background technique [0002] Due to its small size, low vibration and noise, high reliability, small temperature rise and friction loss, and long life, dynamic pressure motors are widely used in various high-precision, high-reliability gyro instruments, and are used in aviation, aerospace, and navigation And other navigation devices are also widely used. Dynamic pressure motors provide stable and reliable moments of inertia for gyro instruments, and their performance directly affects the navigation accuracy and reliability of instruments, platforms, missiles, and spacecraft, and air film stiffness is an important characteristic index of dyna...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem that the measurement spot of the laser triangular light sensor is small, it is easily affected by the change of the reflectivity of the measured surface, thereby reducing the stability of the indication and the repeatability of the measurement, and the larger the working distance of the measurement, the lower the measurement accuracy. Further provide a dynamic pressure motor air film gap measurement device and method based on synchronous phase-shifting interference, which has the characteristics of large measurement working distance, strong anti-interference ability and high resolution; the measurement spot can be adjusted according to the shape and size of the measured surface Shaping can eliminate the influence of the measured surface reflectance on the sensor; the common optical path design is not only conducive to the miniaturization of the device, but also can effectively overcome the influence of the surrounding environment on the sensor

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