Wide-range displacement transducer for measuring linear phase grating profile

Abstract

The invention discloses a profilometry displacement sensor with big measuring range and linear phase grating. Integral cutting parallel spring is constructed by a frame cut by a steel spring plate and a parallel spring, a laser is mounted on the frame; scaleplate grating is fixed to end of the parallel spring; the three gratings are parallel with each other; attachment link is connected with the scaleplate grating, and connected with boning rod via butt, the boning rod is mounted on the butt of spider reed, stylus is fixed to the other end of the boning rod; the light beam outgo from laser passes the three gratings sequentially to generate interference fringe, light-sensitive detector receives the three interference fringes and transform the optical signal to electrical signal, the electrical signal is then transferred to signal processing circuit and proceeded. The invention of profilometry displacement sensor is characterized in that the measurement range is wide, the measurement accuracy is high, and the structure is simple, the cost is low and it is free of assembly error. The sensor can be used to measure the boundary dimension of workpiece, surface shape error, workpiece and surface roughness, the measuring range of the sensor is 0-8mm, resolution ratio can achieve 5nm.

Description

technical field [0001] The invention belongs to displacement sensor technology, in particular to a large-range linear phase grating profile measurement displacement sensor. Background technique [0002] With the rapid development of surface profile measurement technology, the issue of developing large-range, high-precision, and low-cost displacement sensors has become critical. Contour measurement generally uses inductive displacement sensors, which have the problems of small measurement range, high cost and low precision. At present, there are mainly two types of large-scale profile measurement displacement sensors: one is the profile measurement displacement sensor using the principle of laser interference. ([1] Xiao Hong, Wang Xuanxuan, Xie Tiebang. Rolling bearing surface contour profile measuring instrument. Bearing, 6, 2004, p.30-33), compared with grating interferometry, the accuracy of laser interferometry is affected by air composition, pressure, humidity The infl...

AI Technical Summary

Problems solved by technology

However, the cylindrical grating processing must strictly ensure the curvature radius and surface quality of the cylindrical surface, which makes the sensor cost high

In addition, the cylindrical grating profile measurement displacement sensor is difficult to install, has high requirements for bearings, and a slight deviation in installation and manufacturing will prevent the grating from interfering, and the photocell cannot receive effective signals, resulting in measurement failure.

And the linear difference of its measurement, the measurement range and measurement accuracy are far from the theoretical analysis value, the actual measurement range is 1mm, and the measurement accuracy is 10nm

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