地磁辅助惯性导航匹配算法研究

对地磁辅助惯性导航技术的基本原理进行了分析，鉴于采样卡尔曼滤波算法在重力辅助导航中的成功应用，将其用于地磁图形匹配。滤波通过设计少量的σ点，并计算这些σ点的经由非线性函教的传播，从而获得滤波值基于非线性状态方程的更新，较广义卡尔曼滤波具有计算精度高、便于计算的特点。     

A study on driver’s workload of telematics using a driving simulator: A comparison among information modalities

Recently, diffusion of telematics services and an explosive increase of in-vehicle display devices, such as Car Navigation Systems (CNSs), are becoming the new causes of traffic accidents. This is due to ‘inattention’ caused by an increase in the driver’s mental workload while he/she is driving. This situation has lead many countries to consider controlling the use of in-vehicle devices while driving through legislation. This research studies the effect of voice or display information systems on drivers through the Driver Eye Movement Analysis and the measurement of response ability. The experiment is carried out in a driving simulator and the results are presented through the comparative analysis of the driver’s visual field via the gaze tracking device and the average of correct answer rates for arithmetic problems.     

A GNSS Signal Blind-decoding Algorithm at Low SNR

The pseudo-random noise (PRN) code modulated in satellite navigation signals impacts the system positioning performance directly, and the code monitoring is one of the key technologies. However, the received signal is often buried in noise, and the ranging codes can not visible in time domain. Considering local clock bias, the signal model in transmis-sion link is derived in this paper, and a PRN code blind-decoding method is proposed also. It calculates the signal' s cyclic spectrum by using fast Fourier transform accumulation method (FAM) , and estimates the code rate and Doppler frequency making use of the noise eliminating characteristic in non-zero cycle frequency cross-section. Wiped off the Doppler shift,the navigation message or secondary code bits are determined and removed by slide-correlating a small slice of itself with the whole data. The start of the code is determined by stacking multiple periods of the whole data into a code period, and then the whole data is shifted to the start of the PRN code, and is restacked. Then the individual period of PRN code is esti-mated. An experiment for the proposed algorithm is performed by simulated vector signal analyzer (VSA) collected data.The results indicate that the algorithm is effective and reliable.     

A Combination Field Desorpt/Fast Atom Bombardment Source for the Ms-50 Mass Spectrometer

ABSTRACT

Conversion of the combination EI/FD source supplied by Kratos for the MS-50 mass spectrometer to a combination FD/FAB source is described. Sensitivities in the combination source are equivalent to those of the stand alone FAB source supplied by Kratos and the EI/FD source. Some compounds could be analyzed by FAB only, others by FD only and a third group were susceptible to both techniques. The advantage of the combination source is that both techniques may be used without having to change ion sources or perform extensive instrumental manipulations.     

GPS/INS制导导弹运行模型变化定位精度分析

研究了GPS/INS制导导弹定位的新方法.与以前对GPS/INS制导载体建立单状态方程不同,本文对导弹运动过程建立两种模型--机动和非机动模型,分别对应低动态和高动态应用环境.利用伪距和伪距率测量信息进行卡尔曼滤波,特别针对GPS制导的近程导弹运动过程的特点,提出修正交互多模算法能提高模型转换期间的定位精度.仿真结果证明,这种方法定位可以达到实时和高精度,提高载体运动状态改变时的定位精度.提出的方法对提高载体的精确制导有一定现实意义.     

基于Hermite插值的捷联惯导姿态解算算法

将Hermite插值定理用于某远程多用途导弹捷联惯性导航系统的姿态解算 ,解决了弹体高动态特性与相对较低的传感器采样频率之间的矛盾 .对仿真结果进行了分析 ,为远程多用途导弹采用捷联惯导方案获取弹体信息并进行制导提供了可能性 .     

面向飞行器交会对接应用的载波相位差分技术研究

GNSS引导两飞行器交会对接的前提是实时可靠地估计相位模糊度。针对卫星和飞行器的高动态性所引发的频繁换星问题,提出一种实时递归相位模糊度估计方法。该算法能够有效处理失锁所造成的卫星起落现象,同时充分利用历史观测与当前观测方程中部分模糊度分量的关联性,使得模糊度估计的成功率对可见卫星数目的减少不敏感。为了验证该算法在空间飞行器对接中的精度和成功率,采用GPS模拟器仿真两飞行器近程导引段和最终逼近段的过程,应用新算法实时估计两飞行器间相对位置,精度达到亚厘米级水平,成功率在可见星数递减时依然渐进逼近100%。     

航位推算法在导航定位中的仿真研究

航位推算(DR)法最初用于船舶的航行定位中,所使用的加速度计、磁罗盘、陀螺仪成本高,尺寸大.而随着微机电系统技术的发展,加速度计、数字罗盘、陀螺仪尺寸、重量、成本都大大降低,使得其可以在行人导航中得以应用.针对DR算法的原理,利用GPS/INS紧密组合导航系统INS 1200进行导航实验,采集实时数据,利用DR算法以及坐标转换算法对实验数据进行处理,通过MATLAB软件模拟了经过坐标变换后的定位图.仿真结果表明,DR算法在短时间内有较高的导航精度,对短时间导航有较大意义.     

基于GPS和INS的测速方法比较分析

目前常用的测速方法包括测速仪、GPS多普勒观测值测速、INS测速、GPS/INS测速等。文章分析了GPS多普勒测速,INS测速以及GPS/INS测速的基本原理。最后,通过对实测的车载实验数据解算对以上这三种方法进行了详细的比较分析,得出了一些比较有意义的结论。     

实现飞机状态监视的ACARS数据链新应用

法航447空难和马航370失联事件促使航空公司更关注对飞机的监控。分析了常用的飞机通信和监视手段,提出了一种使用ACARS实现飞机状态监视的数据链应用,通过飞机信息处理、消息封装、数据压缩和信息编码4个实现步骤,周期下传包含飞行参数、飞机系统状态和故障告警信息的ACARS消息。该方法间接提升了ACARS网络的信息容量,使航空公司等地面用户能够实时全面监视飞机状态。