Study On Self-calibraton For Key Parameters Of Platform Inertial Navigation System

With the persistent ly development of inertia l techno logy and the accuracy of inert ial platform, there comes increasingly strict requirement on the accuracy of calibration and compensation for the parameters of inertia l platform. Taking the Four- Gimbals inertial plat form for new ballistic missile as object, the methods of calibration with turntable and self- calibration for the parameters are studied, which is the subject of this dissertation.According to the developing history, present sit uation and problems unsolved of the calibration for inertial platfor m at home and abroad, the researching direction and region of this dissertation are determined. With the error models of gyros and accelerometers available, the complete equations of the platform drift rate and accelerometer- group output for the whole platform are derived.In order to eliminate the influence of t ime to time errors about accelerometer offsets and scale factor on calibration accuracy of the accelerometers input-axis misalignments, a 12-posit ion tumb le method is carried out based on the mathemat ical model in C hapter 3,which is derived for the three accelerometers, taking into account the input-axis misalignments, the errors of accelerometer bias and scale factor. A 12- position self- calibration method is also carried out analogously, combining the specialit y of four- gimbals inertial platform. The results of calibration and self- calibration ind icate that the repeatability error of calibration is 3 arc- second or even less, and the accuracy of self-calibration reaches 10 arc-second.Mathematica l model is derived in C hapter 4 for calibtrating and compensating the fixing error of the rotary transformers, whose influence on the measuring accuracy of the attitude angles is analysed. An exper imentation is devised and the result of the experimentation shows that the accuracy of attitude output can reach 20 arc-second after compensated.