李贵琦

李贵琦,1941年生,山东黄县人,1965年哈尔滨工业大学雷达专业本科毕业;研究员级高级工程师,卫星导航博士后指导专家,清华大学卫星导航专业博士生答辩委员。1965～1993年在总参测绘研究所从事科研工作,历任工程师、天文课题组组长、"双星"(北斗卫星导航系统前身)课题组组长、高级工程师。他主持研制的"J05一等天文经纬仪",获1978年全国科学大会奖(证书号0002106),同时参加的"西沙群岛与大陆联测",也获得全国科学大会奖(证书号0002105);由其负责的"双星快速定位通信演示系统测绘保障分系统"科技成果,获1991年军队科技进步二等奖。1993～1999年在总参测绘局任双星筹建办技术组组长、双星筹建办技术处     

共位卫星距离分析

介绍了共位卫星距离的基本概念。分析了共位卫星双星距离的计算方法。针对共位卫星双星距离的计算方法,对影响双星距离计算的因素进行了详尽的仿真,得出了绝对距离与径向、法向和切向3个方向距离的相互关系。着重分析了共位卫星倾角和偏心率矢量的摆放方法,特别是用倾角和偏心率矢量差对共位卫星双星距离进行了分析仿真。     

基于陆基增强系统提高双星定位精度的研究

针对我国自行研制的双星定位系统提出了几种提高其导航定位精度的改进方法，着重研究了通过建立陆基增强系统来提高双星定位能力的技术方案，并对该方案实施的可行性进行了理论分析，讨论了陆基导航台与双星系统的时间同步问题，增强后的双星系统用户端安装导航处理器，工作方式为被动无源工作模式，分析表明，对双星系统增强后，提高了导航的可靠性，减小了定位几何系数GDOP，提高定位精度。     

基于WGS-84的双星时差/频差定位算法及误差分析

研究了低轨道双星通过测量时差和频差对地面固定辐射源进行无源定位的问题。双星时差/频差定位算法是时差、频差单独定位公式和WGS-84地球椭球模型的结合,该算法通过迭代的方法提高了定位精度。文中结合定位误差算法和定位精度的GDOP算法,通过仿真、对比系统地分析了影响双星时差/频差定位系统定位精度的因素,分析结果对双星定位系统的应用具有借鉴意义。     

双星导航系统在海上航标系统中的应用

航标控制系统利用双星导航系统来完成航标的管理、监控以及自动化、信息化、网络化等工作，主要是依靠双星导航系统的定位、短信道通信功能。文中介绍了利用双星导航系统的航标控制单元组成、工作方式以及区域航标控制中心站和全国性区域航标控制中心的组成及工作原理．     

三星定位／DNS组合导航系统仿真研究

双星系统是我国建立起来的一种区域性定位系统．在双星定位系统上加上一颗地球同步卫星可组成三星定位系统，文章分析了三星定位系统的工作原理，并进一步研究、仿真了三星(双星和它的一颗备份星)定位系统与DNS构成的组合导航系统，仿真结果表明了该组合系统不但能有效地提高定位精度，同时还能提供高精度的航向数据，对双星定位系统的推广应用有重要的理论参考意义．     

基于双星定位的定位报告系统

介绍了基于双星定位的定位报告系统的主要功能、构成、工作原理及采用的关键技术。对利用双星定位系统的通信功能进行数字地图传输，采用的压缩算法和传输协议进行了较详细的阐述。     

双星系统对雷达无源定位的可行性分析

双星无源定位系统对地海面雷达辐射进行定位时,存在脉冲信号频差参数提取的模糊问题。提出了一种基于虚拟双星的双时差粗定位方法,可有效解决频差测量的模糊,再结合时差/频差联合定位方法,分析了双星系统对雷达辐射源无源定位的可行性,给出了一些有用的结论。     

基于卫星模拟器的定姿原理

以卫星模拟器为基础,介绍了一种双星定位系统定姿的基本原理,仿真结果表明,应用双星定位系统进行定姿是可行的.     

一锅双星接收亚太5、6号的教训

小张有一套接收亚太6号数字卫视套站。适逢亚太5号世华、数码天空开锁播出,小张便要求朋友阿新帮他用“一锅双星”接收亚太5号、6号C、Ku波段节目。小张原有的器材是中卫1.5米正馈天线一面,PBI-1800C波段高频头一个,数字接收机一台。为了双星接收,阿新买了C波段双星馈源盘、PBI     

Localized positioning in ad hoc networks

Position centric approaches, such as Cartesian routing, geographic routing, and the recently proposed trajectory based forwarding, address scalability issues in large ad hoc networks by using Euclidean space as a complementary name space. These approaches require that nodes know their position in a common coordinate system. While a GPS receiver in each node would be ideal, in many cases an approximation algorithm is necessary for networks with only a few GPS enabled nodes. These algorithms however require collaboration of large portions of the network, thus imposing an overhead for nodes which do not need positioning, or are mobile. We propose local positioning system, a method that makes use of local node capabilities––angle of arrival, range estimations, compasses and accelerometers, in order to internally position only the groups of nodes involved in particular conversations. Localized positioning enables position centric uses, like discovery, flooding and routing in networks where global positioning is not available.     

一种基于RFID和ZigBee技术的局域定位系统

介绍了一种基于RFID和ZigBee技术的室内定位系统的设计。该设计以第二代片上系统CC2530为核心,配合RFID阅读器和标签、以及一些外围电路构成了硬件定位系统。采用基于接收信号强度值(RSSI)的定位技术和最大似然估计的计算方法进行定位。重点阐述了该定位系统的结构和硬件电路设计,分析了定位系统的工作原理、软件流程和定位算法的实现。实验证明该定位系统能够实现室内局域定位的功能。     

A mechatronic positioning system actuated using a micro DC-motor-driven propeller–thruster

One of the greatest challenges facing designers in the mechatronics field is the development of autonomous systems capable of guiding an airborne object along a given trajectory or maintaining its position in a specified location. Nonetheless, developing such ability is essential to support emerging UAV (Unmanned Aerial Vehicle) requirements in the civil and military domains. Accordingly, this study commences by constructing a mechatronic system featuring a manipulator arm actuated by a DC-motor-driven constant-pitch propeller and then develops suitable control schemes to regulate the power supplied to the DC motor such that the manipulator arm is driven through a specified rotational displacement. Three different control schemes are implemented to regulate the displacement of the manipulator arm, namely a fixed gain PID controller, a function-based variable gain PID controller and a fuzzy gain-mixing PID controller. The feasibility of the three control systems is evaluated both numerically and experimentally. It is shown that the fixed gain PID controller results in a significant overshoot of the manipulator arm and leads to a loss of control. However, the function-based variable gain PID controller and the fuzzy gain-mixing PID controller both ensure an accurate tracking performance, even when the manipulator arm is manually perturbed during rotation.     

Investigation of the micro-step control positioning system performance affected by random input signals

This paper gives the results of simulation and experimental investigation on the effects of random signals on the accuracy of micro-stepping control positioning. For studying and simulation of the effect of random noise signals on performance of the accurate position control systems, such as Hybrid Stepper Motors (HSMs), a micro-step driver and controlling unit using PID controller has been designed and constructed. Several parametric studies have been carried out including different white noise power and micro-step per revolution. Tracking problem for a HSM model has been simulated, and the experimental study for similar cases has been carried out by implementing the designed controller in real-time operation by using Real Time Windows Target Toolbox of Matlab software and Simulink. Simulation and experimental results show that random noise source changes current profile and affects the accuracy of positioning. Performance of the proposed PID controller under the implementation of random noise on phases one and two of stepper motor has been proved to be accurate enough even under disturbance load currents, on the system. Experimental and simulation results show the good performance of designed controller in tracking problem, affected by various random noise powers and motor speeds in different micro-step positions. Moreover there is an excellent agreement between experimental and simulation results.     

Single-loop output-feedback positioning technique for servo systems via second-order pole-zero cancellation approach

This article presents an advanced order-reduction technique for servo motor positioning applications by explicitly handling the model-plant mismatches caused by parameter and load uncertainties. The resultant output feedback system establishes an observer-based single-loop structure ensuring first-order position dynamics by the second-order pole-zero cancellation mechanism. Two contributions are provided: first, the plant parameter information-free angular velocity and acceleration observer leading to the first-order estimation dynamics by the proposed gain structure; second, the output-feedback positioning law constraining the closed-loop behavior into the first-order dynamics through the observer-based active damping injection causing the second-order pole-zero cancellation, requiring the only nominal plant parameter values. An experimental testbed using QUBE-servo2 confirms the practical effectiveness of the proposed control scheme.     

Vehicular node positioning based on Doppler-shifted frequency measurement on highway

Vehicular node positioning needs to be quick and precise on highway for safety consideration. In this paper, we present a novel and practical vehicular node positioning method which can achieve a higher accuracy and more reliability than the existing global-positioning-system-based positioning solutions by making use of Doppler-shifted frequency measurements taken by vehicular node itself. This positioning method uses infrastructure nodes which are placed on the roadside every several kilometers as radiation sources to estimate the relative distances of vehicle to the infrastructure node. Through coordinate conversion, we get the absolute coordinates of vehicular node based on known absolute coordinates of infrastructure node. We also analyze the optimal distance of neighbor infrastructure nodes in order to ensure a high accuracy. In addition, simulation results demonstrate that the accuracy of our method with Extended Kalman Filtering (EKF) is superior to the method without EKF.     

基于V90伺服的细筒薄壁绝热层内表面打毛设备定位控制系统开发应用

介绍了一种基于西门子V90伺服驱动的固体发动机内表面绝热层打毛设备定位控制系统开发应用过程,利用西门子公司TIA软件开发了打毛设备控制系统的上位组态,利用西门子公司提供的V90伺服驱动系统及TIA提供的丰富的运动控制函数库,实现了伺服电机的精确位置控制。通过软件开发以及硬件的组态,对该套控制系统进行了试验调试,取得了理想的试验效果。     

Heuristics-based indoor positioning systems: a systematic literature review

Context: Many heuristics-based indoor positioning approaches have been developed to enhance positioning estimation. However, there is no comprehensive survey of these heuristics information and methods. Objective: The main objective of this study is to provide a holistic view and an in-depth analysis of what heuristics information and methods have been used, their general achievements and limitations. This study aims to provide a comprehensive summary to facilitate further research on indoor positioning heuristics. Method: We conducted a systematic literature review (SLR) on indoor positioning heuristics. Results: Ninety-three (93) primary studies were selected. We found two general types of heuristics information and four primary heuristics methods, which we summarised in this paper. We also found that many of these positioning heuristics are tested in experimental settings only. Some heuristics claim practical applications but are not tested for the challenging and typical indoor environments. Conclusion: Most existing heuristics information and methods rely on the assumptions that may not be true in real life environment, hence limiting the usefulness of the positioning outcomes. Based on the analysis of this SLR, we propose two research directions to enhance positioning estimation.     

GPS/GLONASS组合精密单点定位模型探究

根据实测GPS/GLONASS数据,研究GPS/GLONASS组合系统精密单点定位的精函数模型和随机模型。结果表明：GPS/GLONASS时间基准差作为待估参数算法在保持解算精度的同时,能够保持参数的稳定性。GPS与GLONASS卫星观测值的权重比对解算精度有显著影响。权重比合适时,组合系统相对GPS系统的解算精度有所提高;权重比不合适时,组合系统降低解算精度。     

弹载合成孔径雷达成像处理及定位误差分析

论文基于弹载合成孔径雷达（SAR）空间几何关系，描述了雷达信号数学模型；给出了弹载SAR成像方法；详细分析了弹载SAR水平初始方位角，载体速度的测量误差对于成像定位的影响；推导了各种误差影响成像结果的数学表达式；给出了非直线运动大下冲角情况下，误差分析的计算机仿真和在匹配制导中的实验结果。