Strap-Down Inertial Navigation System Sensor Error Model And Simulation Technology

As an autonomous navigation system, Inertial Navigation System(INS) has high performance of anti-interference. However, the navigation error accumulates with the time. Global Navigation Satellite System’s(GNSS) location precision can keep stable for a long time, but its ability of anti-interference is poor. By use of GNSS signal to calibrate the INS location results, GNSS/INS integrated navigation system can greatly improve the overall system performance. Because integrated navigation receivers usually work in high dynamic conditions and complex electromagnetic environment, out-field testing can hardly provide all the required test modes. Fortunately, GNSS/INS integrated signal source has the advantages of low-cost, high dependability and high controllability in testing of integrated navigation receivers. Integrated navigation signal source needs to provide Inertial Measurement Unit(IMU) signal generating and SINS simulation. For this aim, the SINS sensor error model, sensor error transmitting model and inertial sensor simulation algorithm are researched, and SINS simulation software is developed. The main works are as follows:(1) The common reference frames and body attitude algorithms are researched in this dissertation. Several common attitude algorithms are compared.(2) A SINS sensor error model is put forward. To analyze sensor random error, a method based on Allan variance is proposed. On the basis of the SINS navigation equation, the sensor error transmitting formulation is figured out, and the nine-variable state space model is given. For the situation of short navigation time, the state space model is simplified as single channel error model. Aiming at the problem that attitude error calculated by simplified model mismatching the whole model, an improved algorithm is developed in this dissertation.(3) In this dissertation, SINS simulation software is developed, which includes flight track module based on flying kinetics, the algorithm module of 6 degrees of freedom calculating and SINS sensor simulation module. IMU data simulation is carried out, and the simulate IMU data is tested. The testing results show that the simulate IMU data is accurate and reliable.