速率方位平台惯性导航系统研究

为了降低重力无源导航系统成本,在速率方位平台上放置一个重力敏感器,以构成集重力仪和导航仪为一体的系统.根据该系统的特点对速率方位平台惯性导航系统进行了研究,给出了该系统的导航计算公式、速率方位平台姿态角、系统速度和位置的误差方程以及加速度计和陀螺仪的随机误差模型.用MATLAB/Simulink工具对无阻尼和有阻尼速率方位平台惯性导航系统进行了计算机仿真,仿真结果表明带阻尼的速率方位平台惯性导航系统平台误差角和定位误差小,能够满足重力测量和导航要求.     

旋转方位惯性导航系统的研究

为降低陀螺漂移对导航精度的影响，提出了旋转方位的方法，针对轮盘木马惯性导航系统和普通导航系统的陀螺漂移，讨论了用统一的模型进行系统误差分析和对系统进行评定的可能性。在此基础上，对系统误差进行了分析和比较，从而得出结论：旋转方位惯性导航系统的陀螺漂移对导航精度的影响比普通导航降低了0．2％。     

基于手持式GPS野外导航地图的制作研究

手持GPS因其携带方便,价格合适,深受用户喜爱,随着手持GPS导航定位精度不断提高,其应用范围越来越广泛,针对野外工作定位难,可利用地图少等现实情况,提出利用手持式GPS作为测量工具,快速制作野外导航地图,提高野外工作者的工作效率.对所制作导航地图的实用性在一些偏僻的乡村和山区进行了验证,取得了较好的效果,并在野外实习导航和绘制野外测绘控制点分布图上获得成功.     

军事航海训练实验室体系构建研究

依据海军院校学员航海职业素养的训练需求,从军事航海的体系内涵出发,对军事航海训练实验室的任务和体系构成进行了分析,采用布局分布式配置、发挥功能体系的思路,提出了军事航海训练实验室的具体功能和构建配置,构建了较为完善军事航海训练实验室体系。     

导航过程中最短路径的动态调整算法

在导航过程中,当最短路径道路上有拥挤、堵塞或中断的情况发生时,利用Dijkstra最短路径算法中的最短路径长度和前驱结点两个辅助向量数据,可迅速在其邻接结点中选择一条新的最短路径。实现了最短路径的动态调整,从而可以尽快地到达目的地。     

基于Android的手机导航系统设计与实验

针对传统车载导航系统的不足,设计并实现了一种Android的手机导航系统。介绍了系统总体架构和客户端软件结构,重点论述了自我定位、地址查询、好友定位、路线查询以及实时路况五大导航功能模块的设计,并对系统进行了实验。实验结果表明:系统运行稳定可靠,定位和查询精度较高。系统采用开源的Android系统和高德MAP API,具有成本低、便于携带以及系统升级和维护方便等特点,可满足普通大众的出行导航需求。     

复杂道路交叉口的车载导航地图匹配模型

针对地图匹配技术存在的难点,设计针对复杂路口的地图匹配模型,模型综合考虑距离、航向、车速、道路拓扑关系、历史轨迹等多类因素,对相应准则采用了不同权定义和计算方法,并通过实验验证了该模型.     

Mobile robot localization and navigation system based on monocular vision

A system for mobile robot localization and navigation was presented.With the proposed system,the robot can be located and navigated by a single landmark in a single image.And the navigation mode may be following-track,teaching and playback,or programming.The basic idea is that the system computes the differences between the expected and the recognized position at each time and then controls the robot in a direction to reduce those differences.To minimize the robot sensor equipment,only one omnidirectional camera was used.Experiments in disturbing environments show that the presented algorithm is robust and easy to implement,without camera rectification.The rootmean-square error(RMSE) of localization is 1.4,cm,and the navigation error in teaching and playback is within 10,cm.     

基于Kalman滤波器的INS/WSN紧组合导航系统模型

在基于惯性导航系统和无线传感器网络的组合导航系统中,为了解决传统导航信息松组合方法中测量信息可观性较差的问题,提出了一种基于卡尔曼滤波器的导航信息紧组合模型.当无线传感器网络的信号可用时,组合导航系统将惯性导航系统测量得到的未知节点与已知节点的距离与无线传感器网络测量得到的距离作差,差值作为卡尔曼滤波器的测量信息.由于...     

Analysis on Dynamic Performance for Active Magnetic Bearing—Rotor System

In the application of active magnetic bearings(AMB),one of the key problems to be solved is the safety and stabiltiy in the sense of rotor dynamics,The project related to the present paper deals with the method for analyzing bearing rotor systems with high rotation speed and specially supported by active magnetic bearings,and studies its rotor dynamics performance,including calculation of the natural frequencies with their distribution characteristics,and the critical speeds of the system.one of the targets of this project is to formulate a theory and method valid for the analysis of the dynamic performance of the active magntic bearing-rotor systemby combining the traditional theory and method of rotor dynamics with the analytical theory and design method based on modern control theory of the AMB system.     

利用加权法改进的蚁群算法在车载导航中的应用

设计一种专门适用于路径规划的改进蚁群算法,利用图论中的加权图的方法来表示交通网络,通过对蚁群算法加以改进,从距离和时间两个方面来综合考虑最优路径标准.而非传统的仅从距离角度来考虑.结果表明：改进的算法在距离和时间综合方面比传统的方法更优化.为实际车载导航系统中最优路径规划问题的解决提供了一种新方法.     

无迹卡尔曼滤波在新型地形无源组合导航系统中的应用

为了提高自主水下航行器的导航精度,提出了一种新型地形无源组合导航系统.根据水下环境特点和航行器导航高精度和低成本的要求,采用捷联式惯性导航系统、地形辅助导航系统、多普勒速度声纳、电子磁罗经和利用UKF进行信息融合的导航计算机组成新型水下地形无源组合导航系统,并给出了EKF线性滤波方程、UKF非线性滤波方程和导航传感器量测方程.对比仿真实验表明,采用建议的传感器和UKF信息融合方式比采用EKF方式提高了水下航行器导航定位的精度.采用不同的导航传感器和UKF信息融合方法的地形无源组合导航系统可以有效地减小水下航行器导航位置误差,提高组合导航的稳定性和精度.     

航海类专业半军事化管理的研究

为了提高航海类毕业生的素质,国内的航海类高校大都采用半军事化管理。但是在采用半军事化管理的过程中,也遇到了诸多问题,航海教育工作者必须认真对待和解决这些问题,不断创新和发展,才能真正扬长避短,收到良好的管理效果。     

Effects of academic training on metatextual knowledge and hypertext navigation

We investigated the effects of college training on students’ metatextual knowledge, hypertext navigation strategies and their acquisition of problem-relevant information. Ten psychology undergraduates and nine clinical psychology post-graduate students were asked to study a 3,400-word, 14-section hypertext with the purpose of drafting a short essay on a specific, complex issue in the area of teenage psychopathology. The specialists outperformed the novices on a metatextual knowledge test. They spent more time visiting relevant sections of the hypertext, and wrote essays containing more critical information. They also displayed a better incidental memory for the hypertext structure. We discuss the data in terms of the late acquisition of metatextual knowledge and study strategies.     

运载工具导航课程教学研究与实践

本文对运载工具导航课程的教学内容组织和教学方法进行了探讨,提出了“从主干到分支,从感性到理性“的原则以指导课程内容组织和课堂教学,注重激发学生的学习兴趣和培养学生的创造性.     

移动机器人自主导航技术研究综述

介绍了移动机器人的几种导航方式。对自主导航技术的关键技术———路径规划技术进行了深入研究,对人工智能以及多传感器信息融合技术在移动机器人导航中的应用进行了论述,并对移动机器人自主导航技术的发展趋势进行了展望。     

重点学科导航库建设的研究和思考

论述了在建设重点学科网络资源导航库过程中,如何获取学科资源,组织资源,并对所获资源的构架体系进行描述。此外,还指出了网络资源导航库建设的发展方向。     

A first order system model of fracture healing

A first order system model is proposed for simulating the influence of stress stimulation on fracture strength during fracture healing. To validate the model, the diaphyses of bilateral tibiae in 70 New Zealand rabbits were osteotomized and fixed with rigid plates and stress-relaxation plates, respectively. Stress shielding rate and ultimate bending strength of the healing bone were measured at 2 to 48 weeks postoperatively. Ratios of stress stimulation and fracture strength of the healing bone to those of intact bone were taken as the system input and output. The assumed first order system model can approximate the experimental data on fracture strength from the input of stress stimulation over time, both for the rigid plate group and the stress-relaxation plate group, with different system parameters of time constant and gain. The fitting curve indicates that the effect of mechanical stimulus occurs mainly in late stages of healing. First order system can model the stress adaptation process of fracture healing. This approach presents a simple bio-mathematical model of the relationship between stress stimulation and fracture strength, and has the potential to optimize planning of functional exercises and conduct parametric studies. Project (No. 39470698) supported by the National Natural Science Foundation of China     

A first order system model of fracture healing

INTRODUCTION Fracture healing is an important research subject in biomechanics. During the last years, many theories and simulation models have been proposed for de- veloping a comprehensive view of the mechanisms controlling bone morphogenesis. Pauwels (1960) was one of the first authors to propose a theory of tissue differentiation in response to local mechanical stress and strain. He assumed that deviatoric stresses com- prise the specific stimulus for the formation of fibrous connecti…     

基于GPS的叠合梁斜拉桥双层模型修正方法

为了建立实测动响应和桥梁健康状况的实质性联系,提出用双层模型修正方法修正叠合梁斜拉桥理论计算模型.以实测固有频率为第1层修正目标,采用人工调节方法,在可靠范围内变化桥面板质量、网格划分密度、混凝土模量及边跨压重等参数修正模型的动力特性;然后以GPS实测动响应为第2层修正目标,通过逐步减小结构各向刚度EI模拟桥梁整体刚度损伤,采用有限元迭代的方法修正模型的挠度值.以南浦大桥为例,对其进行有限元建模,并利用所提出的方法进行模型修正.分析结果表明,经过第1层模型修正,频率误差的标准偏差小于7%,比初始误差有明显改善;经过第2层模型修正,桥梁跨中挠度误差小于10%,桥梁结构各向刚度EI下降约20%.研究结果表明理论计算结果与实测结果相吻合.