A two-axis laser scanning method and device

Abstract

A novel double-axis laser scanning device drives a large-area scanning mirror which is installed on a mechanical amplification mechanism to produce x axis rotation and y axis rotation by utilizing the transformation produced by the inverse piezoelectric effect of a piezoelectric crystal, and a laser pulse is reflected and scanned. The rotation angle movement law of two axes of the scanning mirror is set by a single-chip microcomputer system. An optical fiber displacement sensor and a photoelectricity axial angle encoder are used for respectively measuring the actual rotation angles of the scanning mirror around the x axis and the y axis, and the actual rotation angles are fed back to the single-chip microcomputer system through an A / D chip. In the single-chip microcomputer system, the ideal output rotation angle of the x axis of the scanning mirror is compared with the actual rotation angle of the x axis, wherein the actual rotation of the x axis is fed back. The ideal output rotation angle of the y axis of the scanning mirror is compared with the actual rotation angle of the y axis, wherein the actual rotation angle of the y axis is fed back. The control errors of the rotation angles of the two axes are obtained. Signals for controlling the rotation angle of the x axis and the rotation angle of the y axis of the scanning mirror are produced through the PID control calculation. The control voltage is output through a D / A chip, the voltage is amplified through a direct current voltage amplifier circuit, the amplified voltage is exerted on a piezoelectric crystal set to enable the piezoelectric crystal set to produce the needed transformation, and the scanning mirror rotates by the corresponding angles according to the control demands.

Description

technical field [0001] The invention relates to the application technology of the inverse piezoelectric effect of the piezoelectric chip and the laser scanning three-dimensional imaging technology. Background technique [0002] Laser scanning 3D imaging technology is a high-tech that integrates optical, mechanical, electrical and computer technologies. It is mainly used to scan the spatial shape and structure of objects to obtain the spatial coordinates of the object's surface. Laser scanning 3D imaging technology has been widely used in many fields, such as reverse engineering in the manufacturing industry to produce new molds, and in medical engineering to obtain 3D images of human bones, teeth and anatomy. In addition, laser scanning 3D imaging technology has important applications in virtual reality, multimedia technology, computer-aided teaching, 3D advertising production, computer geometric modeling, archaeological research, urban modeling, forestry resource exploratio...

AI Technical Summary

Problems solved by technology

The patent applied for (200510082957.6) proposes a two-axis scanner driven by the inverse piezoelectric effect of piezoelectric crystals, but the method described has two deficiencies: on the one hand, the proposed piezoelectric crystal driving mechanism can The area of ​​the scanning mirror driven by it is very small, and it is not suitable for installing a large-area scanning mirror, so long-distance laser scanning and three-dimensional imaging cannot be realized; There is no sensor for measuring the actual rotation angle, and the inverse piezoelectric effect control of the piezoelectric crystal does not use a high-precision closed-loop feedback control system, so the mechanical structure proposed in this patent application cannot guarantee the rotation angle of the scanning mirror around the x-axis and y-axis accuracy, and it is impossible to avoid the spatial displacement of the optical center of the scanning mirror during the two-axis rotation process, which will have a significant impact on the laser scanning accuracy

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