Failure Mechanism Analyzing And Lifetime Predict Method Studying On Laser Gyroscope

The Ring Laser Gyro (RLG) is a new photoelectric inertia sensor based on the optic interference theory. It uses the difference between the frequency of the two beams of light, which run in the opposite direction in the resonant cavity, to measure the carrier's rotate speed and the orientation in the inertial space. It has been widely used in the inertial navigation fields for it's high sensitivity, high precision and broad dynamic range.Because of the complexity of the configuration, the high expenses on manufacturing and producing and the strict demand in technique, the lifetime of the RLG has been put attentions on by both the users and the manufactories.First, this paper analyses the shortage of the traditional lifetime predict method, such as accelerate lifetime test, to the RLG which is a kind of long lifetime products. Then, a new lifetime predict method to the RLG is brought forward based on the study of the failure mechanisms, which are the internal causes of the failure.The failure mechanisms of the RLG are very complex, but the cathode sputtering and the polluting of the reflector are the most important factors among them. The paper finds that the Hydrogen contained in the work gas has an enlarging effect on both of the two factors. And there exists some functional relationship between the quantity of the Hydrogen and the drop of the readout intensity of the RLG. Usually a RLG is defined failed when the readout intensity drops to the 1/e percent of the initial value, so a new idea that using the quantity of the Hydrogen contained in the work gas to predict the life time of the RLG is put forward in this paper.Considered the tiny quantity of the Hydrogen, first we choose the gas chromatography technology to analyze the component of the work gas and to obtain the chromatography curve. Then, treat the curve with the adaptive aperiodic stochastic resonance algorithm in order to eliminate the apparatus noise submerged in the tiny Hydrogen signal. At last, calculate the quantity of the Hydrogen based on that the quantity varies directly as a function of the area of the chromatography curve. This new method can use the limited time, outlay and resource effectively to predict the lifetime of the RLG.Besides, the paper also introduces an on-line lifetime predict method based on the memory model, which was put forward by a United States patent. Since the similar work has not been seen in interior, we hope that it can give us some assist in future work about the lifetime prediction of the RLG.