Research On Error Properties Of Laser Gyroscope With Total Reflection Prisms

The laser gyroscope with total reflection prisms, which adopts the prism with total reflection characteristics to form a closed optical path, has many advantages such as small lock-in, high reliability, and long service life, so that it has broad application prospects on the high precision inertial navigation and other fields. On the basis of existing technology, the analysis of error properties for laser gyroscope with total reflection prisms and further improving the precision of laser gyroscope with total reflection prisms method have important value in military and civil application.In laser gyroscope with total reflection prisms, the error factors of various complex leads to the actual output signal with beat frequency deviating from the ideal value of the gyro, so research on error properties of laser gyroscope with total reflection prisms is very important to improve the gyro precision. In this dissertation, on the basis of the theory of laser gyro, combined with the structure features of laser gyroscope with total reflection prisms, the error properties of laser gyroscope with total reflection prisms is studied by numerical simulation method; By using beam transfer matrix theory, under the condition of frequency stabilization the beam shift in laser gyroscope with total reflection prisms is researched. Frequency stabilization control, intensity control and mechanical dither control are the key technologies in the process of laser gyroscope with total reflection prisms designment. By means of frequency stabilization control, intensity control and mechanical dither control system, the research points out the improvement of the frequency stabilization accuracy, intensity stability, and mechanical dithering system frequency tracking accuracy. The relevant work is supported by research on error properties and the design of the key technologies of laser gyroscope with total reflection prisms. The main content of this dissertation is summarized as follows.The first part focuses on the error properties of laser gyroscope with total reflection prisms. Combined with the structure characteristics of laser gyroscope with total reflection prisms, such as high frequency discharge, heater frequency stabilization, according to the laser oscillation semi-classical theory, by numerical calculation and simulation analysis, the scale factor error and the lock in threshold is studied for laser gyroscope with total reflection prisms. Scale factor error as a function of laser oscillation frequency, loss and gain is given which provides the design index of stabilized control and intensity control of laser gyroscope with total reflection prisms. Lock in as a function of laser oscillation frequency and loss is given.The second part studies beam shift properties of laser gyroscope with total reflection prisms. According to beam transfer matrix theory, a mathematic model of the beam shift in the total reflection prism laser gyros is established. By the method of numerical calculation, the temperature and frequency stabilization system is given respectively, which is caused by the prism interface on the size of the deviation of the beam, so beam shift minimization control scheme is proposed. Beam shift is studied on the influence of scale factor, lock in threshold. Results show that the frequency stabilization system adjust each wavelength when reset one jump to reduce the beam shift on the prism interface. Under the condition of frequency stabilization, according to the heater voltage and temperature on the scaling factor for compensation, compensation of scale factor nonlinearity is of less than lppm, which is improved an order of magnitude than that before.The third part studies the frequency stabilization properties of laser gyroscope with total reflection prisms. Analysis the theory of power tuning characteristic during in the small jitter modulation and the serving element of frequency stabilization, a mathematic model of the frequency stabilization system in the laser gyroscope with total reflection prisms is proposed. The frequency stabilization accuracy is derived as a function of the heater voltage and rate of temperature, and the theoretical calculation formula of best reset jump threshold is given. The results show that temperature rate increases and heater voltage reduce can lead to degradation of frequency stabilization accuracy, and the best reset jump threshold increases with the environment temperature increases. Using variable gain â…¡ type frequency stabilization system and setting best reset jump threshold, the performance degradation of the front and rear of reset jump could be eliminated effectively. Basis on the mathematical model of frequency stabilization system, combining with the principle of adaptive noise cancellation, a new double longitudinal modes adaptive frequency stabilization technology is proposed. Using the FPGA digital platform, the double longitudinal modes adaptive frequency stabilization system with RLS algorithm is designed, the experimental results show that the frequency stabilization accuracy can reach 10-10 orders of magnitude with the double longitudinal modes adaptive frequency stabilization system.The fourth part studies the intensity control system of the laser gyroscope with total reflection prisms. based on the analysis of the each part transfer function of intensity control system, a mathematic model of the intensity control system in the laser gyroscope with total reflection prisms is proposed. studies the main factors of influence steady precision and interference resistance of intensity control system. The results show that mechanical shaking the spike pulse will be introduced by led to a decline in light intensity control system steady-state accuracy, adding a dominant pole in light intensity control circuit, and using I type control system, the steady state accuracy of the light intensity control system could be effectively improve.The fifth part studies mechanical dithering system of the laser gyroscope with total reflection prisms. In order to improve the mechanical dithering drive efficiency and reliability, a mechanical dithering signals separation from the laser gyro output signal of the laser gyroscope with total reflection prisms is proposed, based on the variable coefficient of zero phase bandpass filter and digital phase-locked loop, the mechanical dithering frequency automatic tracking is realized in in the fixed and varied temperature environments.The last part focuses on double longitudinal modes reciprocal bias characteristics of the laser gyroscope with total reflection prisms. Based on the vector form of light wave, a new analysis method of double longitudinal modes reciprocal bias phenomenon is proposed, intuitive showing double longitudinal modes reciprocal bias from the mechanism is what weak longitudinal modes to provide strong longitudinal modes of alternating frequency, for the strong longitudinal modes always work in out of lock-in. basis on the numerical analysis of double longitudinal modes Lamb coefficient, double longitudinal modes reciprocal bias simulation platform of the laser gyroscope with total reflection prisms is proposed, the stability condition of double longitudinal modes reciprocal bias is given, and through double longitudinal modes reciprocal bias test verifies the theoretical analysis result.In this dissertation, the research on the laser gyroscope with total reflection prisms, which lay a theoretical foundation for designing and manufacturing, has solved the core technology of the laser gyroscope with total reflection prisms in the production process, and effectively improved the performance of the gyroscope with total reflection prisms.