Research On Technology Of Orientation And North-Seeking Based On MEMS-IMU

Inertial north seeking technology is an important part in inertial technology field. It isone of the important guarantee technology of modern navigation system s quickly andaccurately orientation. The gyroscope based on MEMS is a new type of angular rate sensor.It has great advantages compared with the traditional mechanical and optic gyro, becausethe MEMS gyro has the advantages of low cost, light weight and low power consumption.The classification of north seeking technology has been introduced and acomprehensive analysis has been done on the development status of strapdown gyro northseeking equipments. We also presents the performance of MEMS-IMU products at present.Combined with the demand of inertial gyro north finder, a comprehensive research has beendone on the north seeking technology based on a existing domestic MEMS-IMU.The static north seeking method(single position north seeking, two position northseeking, four position north seeking), Kalman filtering north seeking and continuousrotation modulation method are presented in detail. Error factors influencing the northseeking precision in each method are analyzed and summarized.Single axis position turntable, single axis rate turntable and corresponding softwareprograms are the basis of our experiments. A code project is designed to receive theMEMS-IMU s output and the original output data is analyzed by using Allan Variancemethod to get the performance of the MEMS-IMU. Two position north seeking experiment,Kalman Filter north seeking experiment and continuous rotatioin modulation north seekingexperiment have been done to verify the feasibility of the north seeking shcme proposed inthis paper and fine the presicion level. The result shows that the accurcy of MEMS-IMUrotation modulation north seeking can reach less than5degree.