Proceedings Article | 20 September 2020
KEYWORDS: Automatic control, Diffraction, Spectroscopes, Measurement devices, Sensors, Electromagnetic radiation, Combustion, Diffraction gratings, Prisms, Optical testing
The possibility of applying spectroscopic measurements in the implementation of multi-alternative automatic control of physical and physicochemical processes that are accompanied by electromagnetic radiation in the optical range is reviewed in this paper. First of all, combustion processes mean that optical spectra contain multilateral and extensive spectroscopic information of the course of this process, which, to form the output vector of the system of multi-alternative automatic control, could be used. The essence of the proposed method is that this versatile and extensive spectroscopic information is given, as a result of measuring the spectrum at predetermined frequencies (wavelengths). It's an output vector and replaces the output vector in the system of multi-alternative automatic control, which in known systems is usually formed using a set of sensors with a matching set of measuring devices. Thus, the system of measuring devices matching the system of various sensors is replaced by one optical spectral device. It's proposed to use grating and prism diffraction spectral devices as optical spectral devices. Since a discrete mathematical expression describes the state vector, the spectroscopic measurements in the form of count-values of the measured spectrum are should be presented. Such count-values values could be obtained if linear-CCD arrays read spectroscopic information. The specificity of the linear-CCD arrays action requires the further development of the theory of spectrum measurement by optical diffraction spectral devices under conditions of spectrum measurement by these devices. From the available ratios describing the obtaining of complex spectra in the output plane of a diffraction spectral device, i.e., on the sensitive surface of the linear-CCD array's pixels, and it's necessary to obtain ratios describing the properties of the signals that are elements of the matrix of the output vector. In this case, the properties of the resulting spectrum assessment vary from pixel to pixel. That means the adaptation and further development of the spectral measurement theory applied to the problems of multi-alternative automatic control, where the output vector from the spectroscopic measurements, is formed. As a result of the performed researches, a complex momentum spectrum of optical radiation in the output plane of the optical diffraction spectral device is formed. And its quadratic detection with subsequent time integration gives an assessment of the energy spectrum of the analyzed optical radiation with a Bartlett spectral window. The pixel of the linear-CCD array, in addition to photodetection, runs integration over the frequency range matching to the frequency domain (wavelengths) and its size along the frequency axis of this pixel, where the pixel is located. An element of the output vector matrix is the result of frequency averaging assessment over the pixel surface of the energy spectrum of the analyzed optical radiation in the vicinity of this pixel. That is a property of the output vector element. The issues of reading spectroscopic information are significant in the framework of the indicated problem, which entailed the development of the architecture of the corresponding devices since the result of measuring the optical spectrum is to obtain an output vector.
