基于FPGA的小型捷联式惯性导航系统研究

发布时间：2018-08-27 20:01

【摘要】：惯性导航系统具有自主性、高隐蔽性、抗干扰等特点,是航空航天和军事领域重要的导航系统,其特点也是其它导航系统无法比拟的。随着微机电系统(MEMS)的快速发展,出现了新一代微型陀螺仪和加速度计,降低了惯性传感器的制造成本,惯性导航系统发展前景一片大好。为了使惯性导航系统在民用领域迅速推广,有必要设计一种低功耗、便携式的小型硬件平台,实现惯导系统的功能。针对此问题,本文以MEMS惯性器件为传感器,FPGA为运算核心构建计算平台,研究了捷联式惯性导航系统。首先,研究了捷联式惯导系统的计算方法,通过分析惯性器件的运动原理,系统性地构建了捷联式惯性导航解算模型。其次,基于FPGA设计了一套小型导航硬件平台,该平台包括传感器模块、运算模块、通信模块、电源模块、显示模块;为补偿惯性导航的累积误差,集成了辅助导航传感器:磁强计和GPS接收机;并在FPGA芯片上,围绕软处理器核MicroBlaze构建片上系统进行算法处理,通过添加外设IP核实现传感器数据采集、接口通讯及相应控制。然后,用C语言作为开发工具设计了导航系统的软件部分。针对FPGA启动加载的问题,提出了双软件工程架构,完成系统上电后的程序搬移。鉴于双软件工程代码都存储在FLASH中,提出了基于同步字的配置文件存储方式,避免了数据的存储冲突,而且也便于分块读取。接着,针对姿态解算误差问题,研究了磁强计和惯导系统的互补滤波数据融合算法,并以二阶低通滤波器为基础推算出互补滤波模型。同时也设计了基于卡尔曼滤波器的GPS/惯性导航航位解算数据融合模型。最后,构建了一套三维姿态测试平台,用以验证互补偿滤波算法的姿态解算效果。进一步对导航系统车载试验,证明了硬件系统的可操作性,并且运行稳定。
[Abstract]:Inertial navigation system has the characteristics of autonomy, high concealment, anti-jamming and so on. It is an important navigation system in aerospace and military fields, and its characteristics can not be compared with other navigation systems. With the rapid development of MEMS (MEMS), a new generation of micro gyroscopes and accelerometers appear, which reduces the manufacturing cost of inertial sensors. In order to popularize inertial navigation system in civil field, it is necessary to design a small hardware platform with low power consumption and portable to realize the function of inertial navigation system. In order to solve this problem, the strapdown inertial navigation system is studied in this paper. Firstly, the calculation method of strapdown inertial navigation system is studied, and the model of strapdown inertial navigation is systematically constructed by analyzing the motion principle of inertial devices. Secondly, a small navigation hardware platform based on FPGA is designed. The platform includes sensor module, operation module, communication module, power module and display module. The auxiliary navigation sensors, magnetometer and GPS receiver, are integrated, and the arithmetic processing is carried out around the soft processor core MicroBlaze on the FPGA chip. The sensor data collection, interface communication and corresponding control are realized by adding the peripheral IP core. Then, the software part of the navigation system is designed with C language as the development tool. To solve the problem of FPGA startup loading, a dual software engineering architecture is proposed to complete the program transfer after the system is powered on. In view of the dual software engineering code is stored in FLASH, a configuration file storage method based on synchronous word is proposed, which avoids the data storage conflict and is easy to read in blocks. Then, the complementary filtering data fusion algorithm for magnetometer and inertial navigation system is studied, and the complementary filtering model is derived based on the second-order low-pass filter. At the same time, the data fusion model of GPS/ inertial navigation system based on Kalman filter is designed. Finally, a set of three-dimensional attitude testing platform is constructed to verify the effect of mutual compensation filtering algorithm. Further vehicle test of the navigation system proves that the hardware system is operable and running stably.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN96

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