基于Kalman滤波的变体飞行器T-S模糊控制

针对变体飞行器的跟踪控制问题,提出了一种基于Kalman滤波的T-S模糊控制方法。考虑飞行器系统状态不可测,引入惯导数据作为辅助信息,利用Kalman滤波算法融合飞控信息与惯导信息实现状态估计。由于变体飞行器在不同变形结构下气动特性变化较大,为便于控制器设计,采用小扰动线性化方法得到飞行器在不同平衡点处的局部线性模型,并通过状态反馈方法设计局部控制器,局部线性模型和局部控制器通过模糊集和模糊规则聚合成一个连续光滑的全局T-S模糊模型和T-S模糊控制器。通过综合Kalman滤波器与T-S模糊控制器得到一个基于Kalman滤波的T-S模糊控制器。仿真结果表明,该控制器在变形过程中能够实现状态估计,保证飞机的跟踪性能。     

基于中值滤波和小波变换的混合滤波方法在推进剂监测中的应用

目前,监测传感器传出信号中混有很多噪声,为提高信号可信度,需要一种有效的信号处理方法。文章基于Matlab仿真环境,完成了信号仿真和滤波算法的设计,重点对单传感器仿真信号的去噪和多传感器信息融合进行了研究,提出了基于中值滤波和小波阈值滤波的混合滤波方案和基于Kalman滤波的信号融合方案。研究工作有:基于高斯白噪声和脉冲噪声的数学特性,合理假设出5种基本信号形式;依据实际数据,完成单传感器和多传感器信号仿真,确定信噪比和均方根误差作为去噪评定指标;综合分析现有的滤波算法的滤波特性,利用不同长度滑动窗口的中值滤波处理实验信号,选取合适长度的滑动窗口。设置对比实验确定小波阈值滤波中的小波基函数选取、阈值计算和分解尺度等参数;融合中值滤波和小波阈值滤波优势,设计混合滤波方案,去除单传感器仿真信号中的噪声;研究信息融合理论在泄漏监测系统中的应用,设置不同融合方式下的对比实验,确立最佳融合方式下的Kalman滤波方案,实现多传感器信息融合。     

基于计算机视觉/GPS/MG姿态测量的盲人行走组合导航方法研究

电子导盲辅助装置(ETA)是解决盲人出行困难的重要手段,而导航是ETA的关键技术.现有的ETA主要用GPS来定位定向,但在城市环境中经常存在GPS信号遮挡导致导航信息丢失的问题.针对该问题,利用视觉导航短时间内定位精度高,输出连续的优点以及 MG(Magnetic Gravity)姿态测量可补偿姿态积累误差的优点,提出一种基于视觉、GPS和MG姿态测量的盲人行走组合导航算法.该方法构建系统误差模型并以Kalman滤波为框架.仿真和实验结果表明,提出的组合导航算法准确度优于单独的导航算法,满足盲人户外安全出行导航的需求.     

基于UKF的双机协同纯角度目标定位路径规划

针对三维空间双机协同定位问题,在无迹卡尔曼滤波的基础上,提出一种规划双机路径的方法。首先,利用双机探测得到的方位角和俯仰角信息,并结合无迹卡尔曼滤波算法估计目标的状态;在此基础上根据交互信息理论提出指标函数的概念,以指标函数最大为轨迹优化的最优性能指标,将问题转化为求双机控制量的最优解;最后,采用遗传算法求解双机的控制量,得到比较合理的双机飞行路径。仿真结果表明,通过最大化指标函数可以有效地规划双机路径,且具有更高的精度和速度。     

大航向角误差情况下飞行中对准研究

为了解决飞行器在大航向角误差的情况下进行飞行中对准的难题,将一种线性大航向角误差模型应用于飞行器飞行中对准的过程.详细推导了线性大航向角误差模型,设计了飞行器在大航向角误差情况下进行飞行中对准的卡尔曼滤波模型,并进行了数字仿真.仿真结果表明,线性大航向角误差模型应用于飞行器飞行中对准,能够很好地解决飞行器在大航向角误差情况下进行对准的难点,并给出了适合于大航向角误差模型的机动方式.最后,提出了线性大航向角误差模型在工程应用中的几点建议     

一种扩展的比例导引规律及其弹道方程的构建

在传统的动力学微分方程的基础上提出了一种扩展的比例导引法 ,并给出了该导引规律下的相对弹道方程。文中的推理过程表明 ,这种导引规律对导弹、目标的运动速度几乎没有限制 ,理论上说明运用该制导规律的导弹将能对付高机动大速度目标 ,其弹道方程的建立 ,使得研究该制导规律下的弹道特性成为可能。     

NONLINEAR FILTERING ALGORITHM FOR INS INITIAL ALIGNMENT

The initial alignment error equation of an INS (Inertial Navigation System) with large initial azimuth error has been derived and nonlinear characteristics are included. When azimuth error is fairly small, the nonlinear equation can be reduced to a linear one. Extended Kalman filter, iterated filter and second order filter formulas are derived for the nonlinear state equation with linear measurement equation. Simulations results show that the accuracy of azimuth error estimation using extended Kalman filter is better than that of using standard Kalman filter while the iterated filter and second order filter can give even better estimation accuracy.     

Development,integrated investigation,laboratory and in-flight testing of Chibis-M microsatellite ADCS

Design, analytical investigation, laboratory and in-flight testing of the attitude determination and control system (ADCS) of a microsatellites are considered. The system consists of three pairs of reaction wheels, three magnetorquers, a set of Sun sensors, a three-axis magnetometer and a control unit. The ADCS is designed for a small 10–50 kg LEO satellite. System development is accomplished in several steps: satellite dynamics preliminary study using asymptotical and numerical techniques, hardware and software design, laboratory testing of each actuator and sensor and the whole ADCS. Laboratory verification is carried out on the specially designed test-bench.In-flight ADCS exploitation results onboard the Russian microsatellite “Chibis-M” are presented. The satellite was developed, designed and manufactured by the Institute of Space Research of RAS. “Chibis-M” was launched by the “Progress-13M” cargo vehicle on January 25, 2012 after undocking from the International Space Station (ISS). This paper assess both the satellite and the ADCS mock-up dynamics. Analytical, numerical and laboratory study results are in good correspondence with in-flight data.     

A residual based adaptive unscented Kalman filter for fault recovery in attitude determination system of microsatellites

This paper presents an adaptive unscented Kalman filter (AUKF) to recover the satellite attitude in a fault detection and diagnosis (FDD) subsystem of microsatellites. The FDD subsystem includes a filter and an estimator with residual generators, hypothesis tests for fault detections and a reference logic table for fault isolations and fault recovery. The recovery process is based on the monitoring of mean and variance values of each attitude sensor behaviors from residual vectors. In the case of normal work, the residual vectors should be in the form of Gaussian white noise with zero mean and fixed variance. When the hypothesis tests for the residual vectors detect something unusual by comparing the mean and variance values with dynamic thresholds, the AUKF with real-time updated measurement noise covariance matrix will be used to recover the sensor faults. The scheme developed in this paper resolves the problem of the heavy and complex calculations during residual generations and therefore the delay in the isolation process is reduced. The numerical simulations for TSUBAME, a demonstration microsatellite of Tokyo Institute of Technology, are conducted and analyzed to demonstrate the working of the AUKF and FDD subsystem.     

基于精确伪距率观测模型的GPS/SINS组合导航系统研究

从泰勒公式及函数矩阵的基本定义出发，推导了考虑位置误差相关项时，GPS/SINS组合导航系统精确的伪距率观测数学模型。仿真结果表明，使用精确伪距率观测模型的伪距、伪距率交替组合导航系统，其位置误差能更好地跟踪GPS系统位置几何误差系数，能更真实地反映载体的短期位置误差，更适用于对航天器或大气飞行器短期位置导航精度要求较高的场合（如把航天飞机或大气飞行器作为高分辨率合成孔径雷达等遥感器的载体）。