Bias Analysis And Temperature Compensation For Laser Gyro With Total Reflection Prisms

Laser gyroscope is a theoretically advanced optic-electronical inertial instrument. Itis the ideal device of new inertial navigation system and widely used in the areas ofnavigation，land guidance，position finding，carrier rocket and guide missile. But,because of the various of errors in laser gyroscope, the enhancing of its precision isrestricted. Therein, bias is one of the three errors of laser gyroscope. The effect oftemperature on the laser gyroscope becomes the main factor of occurring bias. The mainfeatures of the bias are randomness and instability. Therefore, to develop the precisionof laser gyroscope，it is important to do in-depth study of the bias and then take steps tothe bias compensation.The principle and bias characteristics of laser gyros with total reflecting prisms areanalyzed in this paper. Several main random errors of bias are deeply studied with thebias stability method and the Allan variance method. The coefficients of random errorsof a particular model laser gyro are determined by experiments and its correspondingerror characteristics are analyzed either. By comparatively analyzing the bias stabilitymethod and the Allan variance method, the similarities and differences between thesetwo methods are acquired, and a simplified error analysis model based on Allanvariance is presented. According to a lot of temperature experiment data of laser gyros,a mathematics model of temperature compensation for bias is built. By compensatingtemperature, the tendency of its bias drift related to temperature is disappeared, theprecision of the laser gyro is effectively improved. This compensation method of biashas an advantage of low cost, short cycle, high efficiency and preferable compensationeffect. Therefore, it has a strong engineering practicability.