Error Research On Dual-axis Rotating Inertial Navigation With Fiber Gyroscope

High precision SINS needs high-performance inertial sensors to be used with the advanced systems technology. It is too difficult to make high-performance inertial sensors because of the low level of technology manufacturing, unless the regardless of the cost. Therefore, the intensive research focuses on the advanced systems technology. In the traditional systems technology, inertial sensors fixed directly linked in the vector platform for tracking the geographical coordinates of mathematics. Gyro drift and accelerometer bias often caused the system error and the error growth over time, which are the key factors to affect the sins of the output precision of the navigation. Meanwhile, the initial alignment errors and sensors inertial errors interact to each other, showing Schuler cycle, Foucault, Earth's rotation period oscillation, particularly serious is the longitude error growth over time. This paper proposed new rotary technology to improve the system accuracy, which is different from the traditional technology; the inertial sensors are not binding on the carrier but from rotating platform. So the Inertial sensors mounted on a rotating platform, rotating with the rotating platform. The rotary SINS error characteristic of the system is changed by rotating. The system error is periodic modulate not only by the Schuler cycle, Foucault and the Earth's rotation but also by the rotating platform. So the gyro drift and accelerometer bias errors in the projection of geographic coordinates are the angular velocity modulation, and the system error is effectively suppressed.To improve the navigation accuracy of the fiber optic gyroscope inertial navigation system, In this paper, the right dual-axis rotating scheme is put forward on the basis of single axis rotating inertial navigation system's practical research, then research on error analysis of the dual-axis rotating inertial navigation system. Emphatically analyzes the modulation effect of different error sources, and initial calibration by the advantage of rotating, which provide a theoretical basis for the design and implementation of dual-axis rotating inertial navigation system.First, theoretical research on the basic principle of rotating SINS, in this case, analyze the advantages and disadvantages of eight sequence rotating scheme, and the sixteen sequence rotating scheme has been put forward to instead of the former. Simulation verified the feasibility of sixteen sequence rotating scheme.Second, after propose the dual-axis rotating scheme, research on error characteristics of dual-axis rotating INS in two different ways. First, theoretically analyzes the error effect of error sources on dual-axis rotating SINS, which can compensate all the drift error, as well as the misalignment, scale factor error of inertial elements, and navigation tests are made on the experimental system, in the mode of non-rotating, single axis rotating and dual-axis rotating, by way of analysis and comparison on experimental data, verify that the dual-axis rotating system is a high-precision navigation system.Finally, study on the initial calibration of dual-axis rotating system, established the state equation and measurement equation with nineteenth-dimensional estimator, observability analysis is made on the state variable. The simulation experiment shows that the dual-axis initial calibration of inertial navigation system feasibility.