Low-cost Sins / Gps Integrated Navigation System

In this paper,the low-cost SINS/GPS integrated navigation system,which consists of inertial system.,GPS system,ADS and MG,is designed and simulated. Information from navigation sensors is conveyed to navagation calculator and processed in Kalman filtering, the optimal navigation information can be gained. In view of the system?s characteristics, piezoelectric gyro or micromachined gyro is adopted;micromachined accelerator is used;low cost GPS-OEM chip is applied;and Pc/i 04 serial calculator is adpoted.The paper discusses the principles and math models of some inertial devicespiezoelectric device,micromachined device,and so on. The error model of low-cost inertial system is studied and simplified; After the studying of the main error sources of GPS, its model is established. The error models of ADS and MG are analyzed too. After these works, math model of the integrated system is established.The design of SINS/GPS integrated navigation system is stressed on ,which adopts the position-velocity integrated model. Owing to the simplification of the error equation of the low-cost inertial system, the amount of calculation is reduced, the burden of calculator is alleviated,the cost is decreased;Due to the adoption of feedback, both the linear similar degree and the precision of the SINS error equation are all raised. In the calculation of Kalman filtering, square-root filtering method of U-D is used,thus the filter?s data stability is raised.;In the filter,the information from ADS and MG sensors are processed apart from that of GPS in group and in sequence,as can make it sure for the information from ADS and MG to rectify SINS when the signal of GPS is lost. It can also ensure the quality of real-time and decreases the amounts of calculation.According to several typical flight phases,the simulated flight track is designed, three SINS/GPS integrated systems of different performance ranks are simulated.The situation when the signal of GPS is lost is simulated too. The results indicate that: the position precision of the integrated system ,whose gyro drifting is i00degree/hour and whose accelerator offset is 0.OOSg, can reach 60 meters about, it's velocity precision can reach 1 m/s about and its attitude angle precision can reach 0.25 degree about. When the signal of GPS is lost, the growing rate of the integrated system's error is much lower than that of SINS system, two minutes after the lost of the signal, the position error is 370m, the velocity error is 2.4mIs.