A four-degree-of-freedom xy galvanometer scanning device and control method

Abstract

The invention discloses a four-freedom-degree XY vibrating mirror scanning device and control method. The four-freedom-degree XY vibrating mirror scanning device is scientific and reasonable in mechanical-optical structure, and a control scheme is easy and convenient to implement. According to the technical scheme, the method comprises the steps that before laser beam scanning is conducted, firstly, a scanning controller determines a complete scanning path according to the machining task, and on the premise of the given scanning speed, a filter or spectral analysis algorithm is adopted for breaking the complete scanning path up into a direct flow and low frequency component and a high frequency component, wherein the direct flow and low frequency component is a part, with the tread smooth and steady, in the complete canning path, and the high frequency component is a part which reflects a microstructural part in the complete scanning path and a part with the trend varied sharply and repeatedly; when laser beam scanning is conducted, the scanning controller calculates deflection angle coordinate values of an X-axis vibrating mirror reflector and a Y-axis vibrating mirror reflector according to the direct flow and low frequency component and outputs angle deflection which drives the X-axis vibrating mirror reflector and the Y-axis vibrating mirror reflector; and according to the high frequency component, the scanning controller calculates thickness variation values of the X-axis vibrating mirror reflector and the Y-axis vibrating mirror reflector and outputs a voltage signal to control thickness variation of the reflectors.

Description

technical field [0001] The invention belongs to the technical field of optics and electromechanical control, in particular to a four-degree-of-freedom XY vibrating mirror scanning method. Background technique [0002] The laser beam scanning device is the core component of the laser processing machine tool, and the existing laser beam scanning device is mainly based on the XY galvanometer system. The XY galvanometer system includes two reflectors that can be used for fast angle deflection. They are geometrically orthogonally arranged and driven by angle servo mechanisms respectively; the angle servo mechanism can control the laser beam by adjusting the deflection angle of the two reflectors. Set the trajectory to scan continuously on the XY plane. In order to improve the scanning speed and efficiency of the laser beam, in practice, on the one hand, the reflector of the XY oscillating mirror is lightened to reduce its moment of inertia, and on the other hand, a voice coil mo...

AI Technical Summary

Problems solved by technology

Because the voice coil motor is a non-commutated motor through the current control element, it can achieve high repeatability positioning accuracy, but its high-frequency response characteristics are difficult to further improve due to the influence of the strong inductive load characteristics of the winding. At present, the traditional XY Although the galvanometer system can achieve a high linear scanning speed, its scanning efficiency is still low when dealing with complex vector patterns, especially those with a large number of tiny structures, curves, and irregular turns

[0003] In order to improve the scanning efficiency of the laser beam, it has been reported in the literature that the piezoelectric deflection mechanism is used instead of the voice coil motor to realize the angular deflection servo drive of the mirror mirror of the XY galvanometer system, but the mirror size and angular deflection range are small, which limits the scanning range. To deal with complex scanning tasks, especially in terms of containing a large number of microstructure patterns, there is still a lack of an XY galvanometer scanning device and its control method that can take into account the needs of large-scale scanning range, high-efficiency scanning performance, and high-precision microstructure scanning.

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