A high-performance raster scanning control positioning device

Abstract

The invention discloses a high-performance raster scanning control positioning device, which comprises a DC brushless motor, a diffraction grating, an encoder, a phase-shifting and frequency doubling circuit, a programmable counting circuit, a motor driving circuit and a main control circuit, and is characterized in that the encoder transmits detected angular position signals of the diffraction grating to a phase-shifting and frequency-doubling module to process, position counting and position determination are carried out on processed frequency-doubling output signals through a programmable counting module, then position counting and position determination signals are transmitted to the main control circuit, the main control circuit compares the position counting and position determination signals with a target position, control signals are outputted through carrying out algorithm processing on a comparison result, and the motor driving circuit is used to control rotations of the DC brushless motor so as to control the angular position of the diffraction grating. The high-performance raster scanning control positioning device realizes closed-loop control for the diffraction grating, satisfies application occasions in which grating rotations are controlled precisely and stably by using a low-cost and high-performance raster scanning control device, and has very high practicability and universality.

Description

technical field [0001] The invention relates to the field of raster scanning control positioning, in particular to a high-performance raster scanning control positioning device. Background technique [0002] In the application of spectroscopy, as an important analysis method, spectral analysis method plays a great role in scientific research, production, quality control and other aspects. Grating spectrometer is an optical detection instrument used for spectral analysis and measurement. Compared with traditional chemical analysis methods, spectral analysis methods are widely used in physics, chemistry, metallurgy, and agriculture due to their advantages of rapidity, non-destructiveness, and high precision. , environmental protection, medicine and other fields. A grating spectrometer is an important optical instrument that uses a grating as a spectroscopic element and separates monochromatic light of different wavelengths from polychromatic light through the rotation of the ...

AI Technical Summary

Problems solved by technology

Due to the limitation of the screw rod's own structure, its scanning speed is low.

[0007] 2. Poor grating positioning repeatability

[0008] Due to the limitations of the subdivision drive and the mechanical movement characteristics of the motor itself, there are phenomena of synchronous, skipped or out-of-step phenomena, coupled with vibration and other reasons, the scanning repeatability is greatly reduced, and even the general accuracy requirements cannot be met.

[0009] 3. Raster scan resolution is low

[0010] Due to the technical limitations of domestic high-resolution encoders, the purchase cost of high-resolution encoders is too high, and it is difficult to purchase high-resolution encoders due to technical blockade. It is difficult to improve the rotation accuracy of the grating under the condition of a certain design cost

[0011] 4. The design cost of high-resolution raster scanning device is high

[0012] In order to improve its accuracy and resolution, one way is to increase the number of physical engraved lines of the encoder as much as possible, but due to technical and other reasons, the difference between domestic encoders and foreign ones is mainly due to the type of encoder It is relatively single, and there is a big gap in the high-resolution field, and the high-resolution encoders imported from abroad are also very expensive, and even belong to restricted import products; on the other hand, the output sine and cosine The signal is interpolated and subdivided to achieve high precision and high resolution. At present, the more commonly used subdivision method is the arctangent subdivision method

In order to be able to locate the rotation position of the motor in real time, it is difficult to buy a dedicated programmable encoding and counting chip matched with a high-precision encoder in China, and the price is relatively high. The above problems have greatly restricted the development of related domestic precision instrument products.

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