An Image-Based Device for Precise Positioning of Schlieren Knife Edge

Abstract

The invention relates to the field of schlieren edge accurate fixing technology, and particularly to an image-based schlieren blade accurate fixing device. The image-based schlieren blade accurate fixing device comprises a light source, a schlieren mirror, an edge, an axial translation platform, a cutting translation platform, a motion controller, a camera, a lens, a computer and a bracket. The light source performs imaging on a focal plane through the schlieren mirror. In mounting of the schlieren blade accurate fixing device, the edge is approximately mounted on the focal plane, and partiallight source image is cut. The lens 4 performs imaging of the schlieren image of a testing area on the camera. Operation software is installed in the computer for controlling the camera and the motioncontroller. The motion controller makes the axial translation platform and the cutting translation platform move through receiving an instruction of the operation software. According to the device ofthe invention, through combining schlieren image analysis with an electric translation platform, the edge of a schlieren instrument is automatically and accurately fixed in the focal plane and furthermore a cutting amount of the edge can be quantitatively controlled. Furthermore experiment quality and experiment efficiency are improved.

Description

technical field [0001] The invention relates to the technical field of precise positioning of a schlieren knife edge, in particular to an image-based precise positioning device for a schlieren knife edge. Background technique [0002] Schlieren is a commonly used flow field display device, which is very sensitive to light deflection. The knife edge is an important part of the schlieren instrument. Under the condition of a certain slit of the schlieren instrument, the cutting amount of the light source image by the knife edge determines the sensitivity of the schlieren instrument. The experiment has high requirements for knife-edge adjustment: first, the knife-edge coincides with the focal plane of the schlieren optical path (that is, the surface where the light source image is located) to ensure consistent sensitivity and uniform brightness of the schlieren image; second, use a suitable knife-edge cut according to the experimental conditions quantity. [0003] Since the hu...

AI Technical Summary

Problems solved by technology

[0003] Since the human eye can usually only recognize a 10% change in brightness, manual adjustment cannot well meet the above requirements, resulting in an unsatisfactory schlieren image in the experiment

The cutting edge of some schlieren instruments is driven by a manual device such as a readable micrometer card, but the human eye is still required to recognize the image width of the light source, so the accuracy of the cutting amount is still insufficient

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