Rotating Dual-antenna Beidou/MIMU Combined System Key Technology Research

With the development of society,users have increasingly higher requirements on the accuracy of low-cost navigation equipment.MIMU is widely used because of its low cost,but it has the disadvantage of low accuracy and easy divergence.my country's Beidou satellite navigation system has good long-term positioning,so Beidou satellite navigation technology and MIMU strapdown inertial navigation technology can be combined.The rotating dual-antenna Beidou/MIMU combined system obtains the true heading of the system through rotation,without calculating the entire ambiguity of the complex carrier phase.This paper studies the key technologies of the rotating dual-antenna Beidou/MIMU combined system,and its main work and results are as follows:The rotating platform is designed,the driver parameters are configured,and the motor driver program is compiled.According to the characteristics of the motor,the interface of the stationary part and the rotating part is designed to ensure the stability of the rotating system and meet the rotation requirements of the platform.According to the characteristics of Beidou satellite messages and IMU data,FPGA and DSP are used as the hardware architecture,and the FPGA preprocessing function for sensor data is designed.The navigation algorithm of the rotating dual-antenna Beidou/MIMU combined system is implemented on the DSP.From the perspective of time and space,a relatively minimum GDOP star selection strategy based on tracking duration and altitude angle is proposed,which improves the reliability and accuracy of the system.Aiming at carrier phase cycle slip,a high-order difference detection and repair method for carrier phase single difference is proposed to eliminate the change caused by cycle slip.After a long period of static and cart experiment verification,the position information and speed information of the combined system under the unobstructed environment on land are better than the results of commercial OEM boards;the attitude results are compared with high-precision laser inertial navigation data,and the heading angle error is less than 1 °(1?),the horizontal attitude angle error is less than 0.1°(1?).