On the selection of the digital filter at the laser gyrometer output in the mode of measuring small constant angular velocity
The paper describes investigations of a possibility to increase the accuracy of laser gyrometer operating in the mode of measuring small constant angular velocity. The accuracy is increased by noise suppression at the output using various digital filters in the case when the noise amplitude is by several orders higher than measured signal. Noise at the output of laser gyro can be caused by the internal factors: e.g. dither noise, discrete output of pulse-phase detector (PPD), etc., and external reasons, such as vibrating disturbance. Modeling such digital filters as Butterworth-IIR-Filter, Chebyshev II order IIR filter, Blackman-Nuttall-FIR-Filter and the filter based on robust selections of straight regression lines under conditions of vibrations has been performed. As a result of research it has been established, that at reasonable microprocessor resource intensity the filter based on robust selections of straight regression lines most effectively suppresses output noise which allows to measure low constant angular velocity with an acceptable accuracy for a variety of applications with intense vibrations of a base caused, e.g., by engine operation.
 Chen A., Li J., Chu Z. Dither signal removal of ring laser gyro POS based on combined digital filter. Instrumentation and Control Technology (ISICT), 2012. 8th IEEE International Symposium on IEEE, China, 2012, pp. 178-182.
 Zhang Q.H., Hu Sh.M., Lu G.F. Research on new signal processing method of mechanically dithered ring laser gyro. Optical Tehnique, 2010, vol. 36(1), pp. 126-129. [in Chinese].
 Molchanov A.V. Issledovanie konstruktivno-tekhnologicheskikh kharakteristik lazernogo giroskopa s tselyu povysheniya ego kachestva [Investigation of structural and technological characteristics of the laser gyroscope for the purpose of improving the quality]. Ph.D. Thesis, Moscow, 2005, p. 17.
 Saneev I.V. Molodezhnyy nauchno-tekhnicheskiy vestnik - Youth Science and Technology Gazette, 2012, no. 10.
 Nuttall A.H. IEEE Transactions on Acoustics, Speech, and Signal Processing, 1981, vol. 29(1), pp. 84-91.
 Kester U. Proektirovanie sistem tsyfrovoy i smeshannoy obrabotki signalov [Design of digital and mixed signal processing systems]. Moscow, Tekhnosfera Publ., 2010, pp. 124-157.
 Bychkov S.I., Lukyanov D.P., Bakalyar A.I. Lazernyy giroskop [Laser gyroscope]. Moscow, Sovetskoe radio Publ., 1975, pp. 109, 110.
 Lee J., Whaley P.W. Journal of Sound and Vibration, 1976, vol. 49(4), pp. 541-549.
 Saneev I.V. Simmetrichnaya neyavnaya skhema resheniya uravneniya lazernogo giroskopa [Symmetric implicit scheme for solving the equation of the laser gyro]. Abstracts of scientific and technical conference "Student Spring 2010", April 1-30, 2010. Moscow, 2010, vol. Х, part 1, pp. 197-199.
 Ferster E., Rents B. Metody korrelyatsionnogo i regressionnogo analiza [Methoden der Korrelation und Regressiolynsanalyse]. Moscow, Finansy i statistika Publ., 1981, p. 48-88. [in Russian].