| Integrated navigation technology has always been an important development direction in the field of navigation.General single navigation is always inevitably having various shortcomings.The Integrated navigation technology combines a variety of navigation technologies together,and fuse the information from the subsystems,so that the advantages of each subsystem are complementary and improve the accuracy and stability of the navigation system.With the economic development and technological progress,achieving low cost,miniaturization,low power consumption,high precision and stability of the miniature integrated navigation system has great market value and prospects.The IMU of MEMS has the advantages of low cost?light weight and small size,but the inertial measurement unit in MEMS has poor accuracy.It is generally difficult to perform initial alignment and inertial navigation tasks alone.Dual-antenna GPS can provide position and heading information that does not diverge over time,but can not provide a horizontal attitude and output frequency is low.Besides,when disturbed and obscured,the GPS signals are easily lost.In the paper,we use the MEMS system and the dual antenna GPS system in loose model.Based on the Kalman filtering,using information of the double antenna GPS to correct the error of MEMS inertial unit,so that the integrated navigation system can obtain relatively good position and attitude accuracy with lower cost.Firstly,the development status of GPS,MEMS and integrated navigation system is introduced in detail by referring to the navigation literature.The GPS and SINS navigation principles are described,the navigation error is analyzed,and the SINS update equation is deduced.According to the low precision of MEMS gyroscope,the method of initial coarse alignment is proposed.Secondly,according to the GPS and MEMS data format,the process of data acquisition is analyzed.The GPS and MEMS data are analyzed,saved and displayed by Python language multithreading algorithm.The basic principle of Kalman filter is studied.Setting up a model of integrated navigation as the heading angle and position or position information provided by double antenna GPS for observed value.The SINS error equation,system state equation and system measurement equation are deduced.The simulation results show that the Integrated navigation based on Kalman filter can improve the navigation accuracy and stability.Finally,the integrated navigation system is designed with dual antenna GPS and MEMS,which is used in combination of navigation and different models of navigation.The validity of the navigation system and the correctness of the navigation algorithm are verified by the comparison of static and dynamic experimental results.In the case of the GPS signal losing for one minute,in the static experiment,the heading error is less than 0.08 °,the horizontal angle error is less than 0.04 °,the velocity error is less than 0.08 m/s and the position error is less than 0.7m.In the dynamic experiment,the heading error is less than 0.18 °,the horizontal angle error is less than 0.08 °,the velocity error is less than 0.3m/s and the position error is less than 2.2m.Even the loss of yaw or position signal of GPS navigation system caused by the complex environment,the integrated navigation system can timely convert the navigation mode,providing the function of position and orientation with high reliability and well accuracy. |
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