Design Of MINS/GPS Integrated Navigation System Based On OMAP

With the rapid development of Micro Electro Mechanical System (MEMS) technology, Micro Inertial Measurement Unit (MIMU) based on MEMS technology is more and more mature. The error of Micro Inertial Navigation System (MINS) accumulates with time because of its low precision, so it can not work for a long time. Global Positioning System (GPS) can provide high-precision position and velocity data, buts its output frequency is low, and when there are obstacles, GPS will lose signal. MINS can provide high-precision velocity and position data in short period, so the composition of the MINS and the GPS navigation system, can effectively learn from each other, its reliability obviously increased compare with a single navigation system. The major tasks completed in this paper are as follows:1. Initial alignment cannot be done by MIMU itself because of its low precision, so this paper presents a method of using magnetometer to assist it with initial alignment. The Kalman filter which is based on linear model cannot be used in MINS/GPS integrated navigation system because of its large misalignment angle. There are some shortcomings of standard unscented Kalman filter (UKF), such as obvious influences by the values of initial parameters and the model error of system, so this paper proposes to apply adaptive UKF which is based on adaptive principle in initial alignment of integrated navigation system. The model of the MINS according to the characteristic of ADIS16405 MIMU is established, the data of the MINS and the GPS are fused by Kalman filter.2. Hardware of MINS/GPS integrated navigation system based on dual-core processor OMAP3530 of TI Corporation is designed. ADIS16405 which is based on MEMS technology of AD Corporation is adopted for MIMU; OEMStar is the newly high performance-price ratio product of NovAtel Corporation. After completion of hareware design,firstly establishing development environment of embedded Linux system and dual-core communication of OMAP3530, secondly wirting interface drivers and designing application programs of ADIS16405 and OEMStar, lastly accomplishing initial alignment algorithm and integrated navigation algorithm in the OMAP hardware platform.3. Making relate experiment with the system, experimental results show that the velocity error is less than 0.15m/s, the longitude error and the velocity error is less than 3.5m(CEP) and the height error is less than 7m(CEP) in this system , and there are characteristic of small size, low power and low cost in the system, in microminiature integrated navigation filed it has certain reference value.