Huber-based滤波及其在相对导航问题中的应用

研究无人机编队INS/Vision相对导航方法,给出了相对惯导方程的推导过程和相对视线矢量测量方法.应用Huber-based滤波融合相对惯导信息和相对视线矢量信息,估计出无人机之间的相对姿态、相对位置和相对速度.Huber-based滤波是一种混合l1和l2范数最小估计,对受到污染的高斯分布噪声具有一定的鲁棒性.最后通过仿真验证了该相对导航方法的有效性.     

Huber-Based滤波及其在相对导航问题上的应用

研究了一种考虑视觉导航设备输出噪声不符合理想高斯分布时，无人机编队INS/Vision相对导航方法。给出了相对惯导方程的推导过程和相对视线矢量测量原理，应用Huber-Based滤波融合相对惯导信息和相对视线矢量信息，估计出无人机之间的相对姿态、相对位置和相对速度。Huber-Based滤波是一种混合 ， 范数最小估计，对受到污染的高斯分布噪声，该估计方法具有一定的鲁棒性。最后，通过仿真研究验证了相对导航方法的有效性。     

FAST-SR-UKF算法及其在组合导航系统中的应用

为解决无迹卡尔曼滤波（UKF）算法在组合导航应用中遇到的系统模型不确定、系统噪声统计特性未知以及计算误差较大等问题,提出了模糊自适应强跟踪平方根无迹卡尔曼滤波（FAST-SR-UKF）算法,该算法不仅具有传统UKF的优势,而且包含如下特点：通过模糊自适应强跟踪模块,增强了系统对模型不确定性以及噪声统计参数未知的适应能力;利用平方根滤波的思想,提高了模糊自适应强跟踪无迹卡尔曼滤波算法的数值稳定性,改善了由于计算误差导致的滤波发散问题。仿真结果表明：相对于传统的UKF算法,该算法精度更高、鲁棒性更强。     

GPS授时功能及其在内河航道导航中的应用

利用GPS授时功能,实现内河航道中航标灯的亮/灭同步是指示船舶安全运行在河道中的有力保障,为维护水运的安全起到很重要的作用。设计安装亮/灭同步航标灯,实现河道内多盏航标灯同时亮/灭,为船舶驾驶人员安全运行提供更明显的闪光标志和航行线路。在内河特别是运行繁忙、航道狭窄的内河研究应用亮/灭同步航标灯很有必要,且能把航标灯器的水平提高到一个新层次。     

Neuro-fuzzy techniques to optimize an FPGA embedded controller for robot navigation

This paper describes how low-cost embedded controllers for robot navigation can be obtained by using a small number of if-then rules (exploiting the connection in cascade of rule bases) that apply Takagi–Sugeno fuzzy inference method and employ fuzzy sets represented by normalized triangular functions. The rules comprise heuristic and fuzzy knowledge together with numerical data obtained from a geometric analysis of the control problem that considers the kinematic and dynamic constraints of the robot. Numerical data allow tuning the fuzzy symbols used in the rules to optimize the controller performance. From the implementation point of view, very few computational and memory resources are required: standard logical, addition, and multiplication operations and a few data that can be represented by integer values. This is illustrated with the design of a controller for the safe navigation of an autonomous car-like robot among possible obstacles toward a goal configuration. Implementation results of an FPGA embedded system based on a general-purpose soft processor confirm that percentage reduction in clock cycles is drastic thanks to applying the proposed neuro-fuzzy techniques. Simulation and experimental results obtained with the robot confirm the efficiency of the controller designed. Design methodology has been supported by the CAD tools of the environment Xfuzzy 3 and by the Embedded System Tools from Xilinx.     

A model-based sound localization system and its application to robot navigation

This paper describes a mobile robot equipped with a real time sound localization system as well as a sonar system for obstacle detection. The sound localization method is based on a model of the precedence effect of the human auditory system to cope with echoes and reverberations. Sound localization and robot navigation experiments were conducted. The results show that the robot is capable of localizing sounding objects in a reverberant environment and approaching the objects without collisions, even when the objects were behind obstacles. Environment flexibility and error robustness of the system were discussed as well.     

新的鲁棒滤波算法及在微机电系统–惯性导航系统/全球定位系统中应用

为了提高系统对不确定干扰的鲁棒性并保持较高的精度, 提出一种新的鲁棒滤波算法. 当系统满足可检测和可镇定的条件时, 通过引入适当的滤波增益矩阵, 得到指数稳定的滤波器, 从而将不确定干扰对估计误差的影响限制在给定的范围内, 实现鲁棒性和精度的要求. 用微机电系统–惯性导航系统/全球定位系统组合导航系统中得到的试验数据对该算法进行离线验证, 试验结果表明, 新算法的计算量较小, 并且在有不确定噪声干扰的情况下能使系统保持较高的精度.     

一种自适应联邦滤波在车载组合导航中的应用

联邦滤波在组合导航的应用中,具有容错性好、滤波精度高、计算量小以及实时性好的特点,但在无法得到准确的系统模型时,使用联邦滤波会出现滤波精度低甚至发散的情况。针对车载组合导航信息融合的高精度、高可靠性等要求,提出了一种组合导航的自适应联邦滤波算法。其主要思想是以判别观测数据中的野值存在与否为算法切换条件,存在野值时采用改进的增益矩阵滤波处理方法,不存在野值时则采用模糊自适应联邦滤波方法。将此方法用于SINS/GPS车载组合导航系统中,实验表明,采用的这种自适应滤波方法,能够有效抑制滤波发散,其滤波精度和收敛速度要优于常规联邦滤波,是一种有效的车载组合导航算法。     

障碍物存在的最短路径算法及其在车载导航中的应用

车载导航系统中的动态路线选择是其必备功能之一,文中分析了经典Dijkstra算法存在的不足,并在此基础上,采用优化的邻接矩阵存储结构,讨论了有障碍物存在情况下的最短路径问题。同时用Vc＋＋与Mapx实现了有障碍物存在的动态最短路径算法。实验结果表明,该算法能有效求出有障碍物存在时的最短路径。     

基于奇异值分解的鲁棒容积卡尔曼滤波及在组合导航中的应用

为了提高GPS/INS 组合导航系统对异常观测值的鲁棒性, 引入??∞ 滤波思想提出一种新的非线性鲁棒滤波. 分析H_∞ 鲁棒容积卡尔曼滤波中不同约束水平对滤波结果的影响, 指出在一定范围内当约束水平越小时, 系统的鲁棒性越强, 但容易造成Riccati 不等式无解, 导致滤波发散. 采用奇异值分解代替容积卡尔曼滤波中的Cholesky 分解, 改善了滤波的稳定性, 放宽了??∞ 鲁棒容积卡尔曼滤波器对约束水平的要求. GPS/INS 组合导航实验验证了该滤波方法的正确性和优越性.

     

基于北斗卫星导航系统在旅游行业中的研究及应用

当前,随着北斗卫星导航系统的进一步完善和应用,并在“智慧景区”这一背景下,在旅游景区信息化建设中导入北斗卫星导航系统,符合位置服务产业的进一步发展,也是对公共服务和社会管理的进一步创新。基于此,本文就北斗卫星导航系统在旅游业中的研究及应用做了叙述,     

多线程技术在车辆导航定位系统中的应用研究

摘 要：对引入多线程技术以提高车辆导航软件系统处理速度的方法进行了初步的分析与研究。结合应用实践，对电子地图的读取与显示、GPS定位数据的接收与处理、地图匹配等关键问题提出了解决方案。     

矿井组合导航系统的设计与应用

针对矿井捷联式惯性导航系统（SINS）误差累计的问题,提出了一种基于射频位置修正技术的矿井组合导航系统。系统将射频标签存储的实际位置和SINS解算位置的差值作为量测量,利用Kalman滤波器估计并补偿SINS存在的陀螺漂移和加速度计零偏。该方法在修正点对误差估计精度高,收敛速度快,能够对SINS累计误差进行一次性修正。     

飞行器气动模型辅助导航方法的研究概况与进展

气动模型辅助导航是一种新型的导航方法, 将描述飞行器飞行状态的气动模型信息与现有导航系统信息相融合, 可以提高导航精度和可靠性, 近年来受到国内外学者的关注, 有望成为飞行器的新型自主导航方法. 通过对气动模型辅助导航方法研究现状的调研和分析, 阐述了该导航方法的概念与原理; 分析了目前主要的3 种技术方案—–气动模型/惯性导航融合、气动模型/卫星导航融合、气动模型/惯性/卫星导航融合的各自特点; 对气动模型辅助导航方法与当前几种主要的辅助导航方法进行综合比较, 分析了该方法的技术优势与应用前景; 结合目前的研究现状, 探讨了气动模型辅助导航方法后续研究的关键技术和发展方向. 气动模型辅助导航方法与飞行器的气动模型特性、制导、导航和控制流程密切相关, 该方法的研究有助于推动导航、制导与控制(GNC) 3 个方向的各自发展和深度融合.

     

Modeling users on the World Wide Web based on cognitive factors,navigation behavior and clustering techniques

This paper focuses on modeling users’ cognitive styles based on a set of Web usage mining techniques on user navigation patterns and clickstream data. Main aim is to investigate whether specific clustering techniques can group users of particular cognitive style using measures obtained from psychometric tests and content navigation behavior. Three navigation metrics are proposed and utilized to find identifiable groups of users that have similar navigation patterns in relation to their cognitive style. The proposed work has been evaluated with two user studies which entail a psychometric-based survey for extracting the users’ cognitive styles, combined with a real usage scenario of users navigating in a controlled Web 2.0 environment. A total of 106 participants of age between 17 and 25 participated in the study providing interesting insights with respect to cognitive styles and navigation behavior of users. Studies like the reported one can be useful for modeling users and assist adaptive Web 2.0 environments to organize and present information and functionalities in an adaptive format to diverse user groups.     

An adaptive filter with periodic gain, and its application in autonomous satellite navigation

In the paper an Adaptive Filter with PEriodic Gain (AFPEG) is presented, which is applicable to Discrete-time Linear Periodic Systems (DLPS) and nonlinear systems with a periodic nominal trajectory. Its convergence properties subject to the DLPS are proved. Compared to conventional adaptive filtering algorithms, the AFPEG reduces on-line computation with limited storage requirements. The AFPEG is applied to an autonomous satellite navigation system. Simulation results demonstrate its effectiveness in improving the accuracy of navigation.     

面向三维导航的智能终端传感器数据处理技术

针对智能终端传感器在三维场景导航交互中不稳定问题,提出了一种基于可变平滑归一化模型的传感器数据处理算法.根据传感器数据特点和不同滑动平滑模型数据处理的特性,将不同平滑模型进行组合,并实现平滑窗口可变;同时,运用归一化算法,对数据进行等距处理.在基于终端的三维导航交互系统的实验结果表明,所提算法对传感器低频数据处理后,数据标准方差减小了71.3%,明显地减少了数据扰动;对高频数据处理后,数据标准方差减小了7.9%,有效地保留了信号特征.所提方法能够提高智能终端在三维导航交互中的稳定性和连续性.     

Detecting and diagnosing mistakes in vision-based navigation

Robust mobile robot navigation is an open problem. Navigational mistakes are inevitable due to the characteristics of sensors, models, actuators, and natural environments. This paper describes how to detect and diagnose mistakes that autonomous mobile robots make while navigating through large-scale space using vision. Mistakes are perceptual, cognitive, or motor events that lead a robot astray from its intended route. Detecting and diagnosing a mistake involves realizing that this has happened and determining what the mistake was and when it happened.

The approach described in this paper handles mistakes explicitly. Mistakes are detected by looking for mismatches between observations and expectations. Detailed symbolic representations of visual information support comparing observations and expectations augmented by a priori knowledge. Mistakes are diagnosed by examining knowledge from a variety of sources, including a history of the mobile robot's observations and actions. A computer program called implements this approach in simulation and provides experimental results that demonstrate the feasibility and potential of the approach.     

Microprocessor debugging techniques and their application in debugger design

Every microprocessor-based system needs powerful debugging tools. Debugging power strongly depends on a mechanism of control exchange between the debugger and an application program. Several implementation methods of such a mechanism are briefly described and compared in this paper. It is shown that conditional breakpoints facilitate a semantics-oriented approach to program debugging. Some debugging techniques derived from elementary control-exchange mechanisms are proposed. Most of the techniques discussed are implemented in the MD-86 debugger designed for the Intel 8086 microprocessor. The debugger itself is also briefly described.