Wavelength signal demodulation method for optical displacement sensor

Abstract

The invention relates to a wavelength signal demodulation method for an optical displacement sensor. According to the technical scheme, a color sensitive element which is provided with two different junction depth has different response characteristics to incident light in different wave length, output signals, namely, narrowband diffraction light, of the optical displacement sensor are input to the color sensitive element, the color sensitive element outputs two circuits of response currents, the two circuits of response currents are processed through a logarithmic transformation circuit and then logarithms of a ratio between the two circuits of response currents are obtained, demodulation voltage which is in linear relationship with the wave length is output, the demodulation voltage is conversed into digital values through an A / D converter to be guided into a calculation demodulation module, displacement information can be obtained due to performing interpolation budgeting on the demodulation voltage, and displacement monitoring of the displacement sensor is achieved. The wavelength signal demodulation method for the optical displacement sensor has the advantages of enabling a wavelength signal demodulation system to be small in size and light in weight, being simple in signal processing, rapidly responding to incident light signals, achieving high dynamic displacement monitoring, enabling a temperature compensating circuit to be added and being strong in environmental suitability compared with other demodulation schemes.

Description

technical field [0001] The invention belongs to the field of aviation signal processing, in particular to a wavelength signal demodulation method of an optical displacement sensor. Background technique [0002] With the development of optical transmission flight control technology, the research on optical displacement sensor continues to deepen, and the demodulation of the output signal of optical displacement sensor has become the research focus. The tuning task is to obtain the center wavelength, and then obtain the sensor displacement. In the current research, the wavelength is mostly obtained by using a spectrometer to read the spectral information into the computer, and then use software to process the spectral data to obtain the central wavelength. This method can be used in laboratory research and also meets the general accuracy requirements. There are insurmountable problems in the realization of engineering applications in the control system: the on-board control s...

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Problems solved by technology

In the current research, the wavelength is mostly obtained by using a spectrometer to read the spectral information into the computer, and then use software to process the spectral data to obtain the central wavelength. This method can be used in laboratory research and also meets the general accuracy requirements. There are insurmountable problems in the realization of engineering applications in the control system: the on-board control system generally requires a response frequency above 100Hz, and the spectrometer is an integrating optical instrument, which needs to integrate the optical signal first and then process it. If you want to obtain high resolution, then The amount of collected data must be increased, which leads to a sharp increase in the time spent in data transmission and processing. It usually takes 20-40ms to complete the above integration, collection, transmission, and processing, so that excellent dynamic characteristics cannot be obtained; Aircraft equipment requires small size and light weight, while the spectrometer itself has a large volume and weight, which varies depending on different models, generally above 300g; the spectrometer cannot work without a computer and its operating system, which will inevitably increase the system volume and complexity; the spectrometer It cannot be used under harsh external conditions such as high and low temperature, vibration and dust

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