Development Of Vehicle-mounted Beidou Data Rate Increasing Device

Attitude measurement technology is widely used in vehicle motion information measurement and intelligent control.Multi-antenna navigation satellite is a rising technology in recent years,but its update frequency is low,environmental adaptability is poor,accuracy is affected by baseline length,and real-time performance is poor.These characteristics greatly limit the application of this technology in vehicle attitude measurement and attitude control direction.This paper focuses on how to improve the data update rate,accuracy and environmental adaptability of the navigation satellite attitude measurement system,aiming at developing a low-cost and high-precision auxiliary attitude measurement device to meet the practical application requirements of the navigation satellite attitude measurement technology.In this paper we call it data rate increasing device.Based on the three-antenna BDS attitude measurement system,this paper proposes a scheme based on MIMU-assisted BDS attitude measurement,and develops a Beidou data rate increasing device.The overall test platform of the system was built,and the error characteristics and compensation methods of MIMU were analyzed.The combined attitude measurement system algorithm was designed.Finally test the system,it demonstrates that the Beidou data rate increasing device designed in this paper can improve the BDS attitude measurement system.The performance meets its position measurement requirements on the anti-chemical vehicle.The main work of this paper is as follows:(1)The overall design and implementation of data rate increasing device: According to the previous research,the micro-inertial attitude measurement system based on MIMU is used to assist BDS attitude measurement.The hardware circuit platform based on ARM architecture is designed.The bottom driver and upper application program are designed based on C language,and the complete system is constructed.(2)MIMU error analysis and compensation: The random error and deterministic error of MIMU,the core component of the system,are analyzed.The MIMU error is calibrated and compensated,and the parameters of Allan variance random error are identified.The feasibility of MIMU raw data denoising is verified by using low-pass filter and wavelet analysis of Matlab,and a temperature compensation model is designed to suppress the zero-offset drift of MIMU with temperature.(3)Principle of integrated system and filter design: The attitude measurement principle and inertial attitude measurement principle of three-antenna BDS are analyzed and deduced.The MIMU/BDS loose combination scheme is designed.The extended Kalman filter is designed to combine the attitude,velocity and position information of the two systems.The filter design is verified by simulation with Matlab.(4)System test verification: In order to verify the performance of data rate elevator,environmental test and static and dynamic test are designed.The environmental test results show that it meets the requirements of Engineering application.The updated frequency of the combined attitude measurement device is 200 Hz,which is 20 times higher than that of BDS.Static experiments show that the horizontal accuracy of the combined attitude determination system under static conditions is about 0.2 degrees,which is 0.4 degrees higher than that of BDS alone,and the heading accuracy is about 0.5 degrees,which is about 0.3 degrees higher than that of BDS alone.The dynamic test is based on high precision fiber optic inertial navigation system.The results show that the average error of horizontal attitude and heading of the integrated attitude determination system is less than 0.5 degree and 1 degree respectively under dynamic conditions.The occlusion test shows that the combined attitude measurement system can maintain the stability of the attitude measurement under the short-term loss of lock of the BDS.The results above show that the data rate increasing device developed in this paper meets the requirements of the vehicle in practical use,and has low cost,small volume and strong reliability.