The goal of this work is to identify the main source of noise in the output signal of a fiber-optic gyroscope (FOG) and ways to reduce it. To achieve the stated goal, two mathematical models of the noise component of the output signal of the FOG were developed. These models are based on fundamental expressions defining shot and thermal noise, as well as an expression for the excess noise of an optical radiation source. The general expression of the analytical model takes into account the four fundamental sources of noise in FOG. Their influence on the output signal noise is expressed through the relation between the measured optical radiation power and the angular velocity acting on the FOG. The computer model was developed in the “Octave” environment. Model performs cyclic execution of the FOG operation algorithm with a closed feedback loop for measuring angular velocity. In the computer model, noise from four independent sources is added to a given useful signal. An array of model output data is generated. The noise power spectral density is calculating. The paper analyzes the influence of FOG circuit parameters on the noise level. The noise source having the greatest significance in the output signal was identified. To confirm the correctness of the models, a comparison was made between the simulation results and the noise of commercially produced FOG. The model error is no more than 10%.
Read full abstract