Research On The Micro-gyroscope Of G-sensitivity Error Analysis And Compensation Method In GNSS/MIMU Integrated Navigation System

Now, GNSS/MIMU deep integrated navigation system is a research hotspot in navigation technology. The guided weapon of high-dynamic is adopted as application background, and GNSS/MIMU integrated navigation system is selected as the research object in this paper, according to the issue that MEMS gyro shows obvious g-sensitivity error in high dynamic environment, in which the error analysis and compensation method research is carried out from integrated navigation at the angle of law. The main work includes the following three points.First, a micro gyro error model considering g-sensitivity is build, and three expression forms and measurement error model of micro gyro g-sensitivity in MIMU is deduced aiming at the characteristics of the micro gyro’s different dynamic behavior. Theoretical analysis indicates that when using integrated navigation of position and speed, the position and velocity precision of the system mainly depends on the accuracy of observation. G-sensitivity of the gyro has very small effect on the system, but it will directly affect the attitude precision of the system, and the higher the dynamic of the carrier, the greater the effect.Second, the observability of the micro-gyroscope of g-sensitivity error on GNSS/MIMU integrated navigation is analyzed by using global observability analysis method. The result shows that when designing the reasonable maneuvering conditions, the system is considerable by the providing position and velocity of GNSS observations. In addition, the sufficient condition of global observability is provided. According to micro gyro of g-sensitivity error model, three different forms of kalman filter are designed to provide theoretical basis for the realization of g-sensitivity error compensation.The last, based on the integration of integrated navigation semi-physical simulation platform, the influence of micro gyro having g-sensitivity error to the properties of integrated navigation is simulatedly analyzed. The conclusion is in line with the theoretical analysis, which indicates that the g-sensitivity error has primarily affected on attitude accuracy of the integrated navigation in high dynamic applications. When the acceleration of the carrier along the micro gyro sensitive axis direction is 50 g, the corresponding axial attitude angle error is about 3.49 degree. And the attitude accuracy is significantly lower. However, the trajectory is designed on the basis of Global objectivity sufficient conditions, then using the designed kalman filter to make compensation of g-sensitivity and promote the accuracy of the GNSS/MIMU integrated navigation in high dynamic.