Research On Technology Of Integrated Navigation System Based On IMU

As the essential device of the flight vehicle, the navigation system reflects the important information of the flight states. As navigation technology is becoming more diverse, the integrated navigation system that combines several different navigation technologies has gradually replaced the navigation system based on the single navigation technology which has not met the requirements of the modern navigation application in the modern world.With the developments of the MEMS technology, MEMS-based IMU(Inertial Measurement Unit) has the characteristics of small size, low power consumption and own digital interface that could improve the integrated levels of the integrated navigation system. So the IMU-based integrated navigation system has a wide prospect in the modern navigation application. The main contents of this paper are as follows.(1) The concepts and technological terms that were relevant to inertial navigation were introduced in this paper, and the defects of magnetoresistive sensor in the practical application were analysed in detail.(2) The system structure of the integrated navigation system based on IMU was designed in the paper. The connection between the different modules of the system and ways of the information interaction between the different modules were illustrated in detail. At the same time, the key performance parameters of the devices used in this system were shown in the following contents. The algorithm adopted in the system was analysed in detail.(3) Based on the current research and experimental conditions, the circuit designs of the two subsystems including SINS subsystem and the magnetoresistive sensor subsystem were completed. At the same time, the elementary design of the programme was illustrated as well.The details of the design of the circuit modules of two subsystems were analysed in this paper, such as the design of the power module, the design of the MCU minimum system and the design of the different communication interfaces.(4) Performance tests of the two subsystems were carried out. And the method of error compensation for SINS subsystem was introduced. At last, the results of the test were analysed while the measurement error of SINS subsystem was compensated. The factors that lead errors and the method of error compensation for magnetoresistive sensor subsystem were illustrated as well.The two subsystems of the integrated navigation system designed in this paper now could measure the static attitude angle. The measurement error of the yaw angle could be controlled at-1°to+1°in horizontality. The measurement error of the pitch angle and roll angle are still not good, so further improvement of the compensation algorithms are still needed.