A novel method of combined interval analysis and homotopy continuation in indoor building reconstruction

In this article, several mathematical and statistical methods for uncertainty modelling in indoor buildings are investigated. To reduce the time and cost of the indoor building data-acquisition process, the Trimble LaserAce 1000 rangefinder is used. The accuracy of the rangefinder is evaluated and a simple spatial model is reconstructed. The rangefinder has been used for forest applications to measure the height of trees. In this article, the rangefinder is used for indoor building environment data collection and mapping. The rangefinder was calibrated using a least squares adjustment algorithm and a novel method of interval-valued homotopy as a continuous deformation that reconstructs straight lines or algebraic curves between any pair of three-dimensional data. Homotopy gives better results in term of root mean square error than conventional surveying engineering methods where, in some cases, cubic homotopy gives results 11 times better than conventional methods.     

A Method of Estimating the Accuracy Characteristics of Radio Rangefinder Measuring Instruments Using Precision Laser System Measurements

A new method of estimating the accuracy characteristics of radio rangefinder measuring instruments using laser system measurements is proposed. Smoothed results of laser system measurements, reduced to the same coordinates and to the same instant of time with measurements of the radio systems, are used as standards.     

利用光纤检定激光测距仪的研究

为保证激光测距仪的精度和可靠性,必须要对它进行定期检定.常用的检定法是在经过精密测量的野外基线场上采用六段比较法求得.而这种野外基线场需占用大量的土地资源,检定受地质条件、地理位置、地面建筑构造、气象与温度等环境因素的影响,并且野外作业工作量大,一直是国内外研究所关注的问题.本文通过利用光纤放入室内,代替野外基线来检测激光测距仪这一国内外所关注的问题进行了初步的理论分析与实验研究.分析了用作基线的光纤类型的选择以及耦合方式的选取,研究了耦合、光波、温度对光波在光纤中传输光程的影响.理论分析与实验验证基本符合,说明用光纤在室内代替野外基线来检定激光测距仪是可行的.     

手持式激光测距仪检定方法及系统研究

针对现有手持式激光测距仪检定方法所需场地大、室外环境干扰因素多的问题,提出了一种“小空间长距离”的测量方案,基于此方案研制的手持式激光测距仪检定装置,以高精度全站仪的示值作为长度基准,利用镜面反射原理,在室内16 m长导轨上复现50 m标准长度,消除了野外测量中环境因素的影响。实验结果表明,检定系统满足JJG 966-2010《手持式激光测距仪》检定规程中示值误差检定技术要求,可以实现对手持式激光测距仪示值误差的检定。     

基于模糊神经网络的包装机械臂定位方法研究

目的 为提高包装机械臂的抓取精度,文中基于模糊神经网络设计一种包装机械臂定位方法。方法 将激光测距仪与工业相机融合,可实现目标点的初步定位并得到位姿偏差。以机械臂末端位置误差补偿为例,设计一种模糊神经网络控制器,可实现PID控制关键参数的在线调整以提高误差补偿精度。进一步地,采用果蝇优化算法实现神经网络控制器初始值的优化,可提高控制系统性能。最后,进行实验研究。结果 实验结果表明,机械臂定位算法可使最大绝对误差从7.704 9 mm下降到1.424 2 mm;平均绝对定位误差降低约82.5%;机械臂执行效率与对照组相当。结论 该定位方法可以大幅度提高包装机械臂定位精度,可满足包装、化工、食品等相关行业要求。     

1.2 km标准基线环境参数自动测量系统研制

为提高野外测量折射率补偿实时性,研制了1.2km标准基线环境参数测量系统,该系统采用一种硬件分组和软件并行采集方案,将系统传感器数据采集的正确率提高到98%以上,82个传感器完整循环采集一次的时间小于7s。计算出传感器7s采样间隔温度变化量,分析评估折射率补偿结果,为野外标准基线测量提供科学的视角,量化寻找基线理想的测量时段,使延时温差小于0.05℃,高精度测距仪基线测量时的折射率修正误差控制在5×10^-8内。     

Optically heterodyned 25-GHz true-time-delay lines on thick LD-3 polymer-based planar waveguides

Synthesis of the LD-3 electro-optic polymer has resulted in a highly reliable nonlinear organic material. Such a success has been impeded from further progress because the LD-3 films produced thus far are too thin (<0.5 mum) to form a waveguide. Further details of material synthesis have to be studied to solve this problem. We report the formation of thick LD-3 films ranging from 1.2 to 2.4 mum by introducing cyclopentanone as the new solvent in polymer synthesis. The formation of multimode planar waveguides on silicon with a waveguide loss of approximately 1.3 dB/cm at 1.3 mum is demonstrated. Preliminary studies aimed at forming true-time-delay lines are conducted by use of various waveguide lengths in conjunction with an optical heterodyne technique. Waveguide settings equivalent to different true-time-delay lines with a delay time of up to 0.27 ns and a base bandwidth of 25 GHz are demonstrated with a signal-to-noise ratio of 15 dB.     

Analog Neural Network Implementation for a Real-Time Surface Classification Application

This paper deals with the implementation of a CMOS analog neural network (NN) that has to be integrated in a new kind of optoelectronic measurement system. The aim is to achieve real-time surface recognition using a phase-shift rangefinder and a neural network. NN architecture is a multilayer perceptron (MLP) with two analog input signals provided by the rangefinder, three processing neurons in the hidden layer, and one output neuron whose output voltage indicates the detected surface. As the complete structure is analog, no analog-to-digital conversions or signal processing between the rangefinder and the network is necessary. Furthermore, the 3.3-V voltage supply, relative to the chosen CMOS 0.35-mum technology, allows to reduce the system power consumption. This paper focuses on the implementation in an ASIC of an elementary part of the NN, called neuron, and on the achievement of the complete NN from the integration of three ASICs in a printed circuit board. Comparisons between ideal case, simulations and tests are detailed in order to validate the design and the good functioning of the complete structure.     

HY-2卫星激光观测精密定轨技术

2011年8月16日发射的海洋二号(HY-2)卫星是中国第一颗海洋动力环境卫星,配备的卫星激光测距跟踪系统即作为HY-2卫星定轨基准系统,同时又是HY-2卫星定轨系统之一。本文较为详细地介绍了HY-2卫星激光观测、轨道预报和激光跟踪系统(SLR)定轨技术,并对SLR定轨结果进行了初步检验。     

基于北斗多星信号融合解析的浮标现场校准技术研究

采用高精度载波相位差分（RTK）技术,通过融合解析多星（中国北斗、美国GPS和俄罗斯GLONASS）定位信号,实现全天候、高精度和全参数（波高、波周期和波向）现场实时校准技术。通过反复多次测试,单星、双星和多星系统测量精度分别可达到0.05 m、0.03 m和0.02 m;波向最大示值误差为3.52°。较大幅度提升了我国波浪仪器校准技术水平。     

自动打铃器电路设计

介绍了LD 6 2型多功能定时模块的使用方法 ,并用其设计了简便、经济、实用的自动打铃器电路。     

HY-2卫星DORIS精密定轨技术

2011年8月16日发射的海洋二号(HY-2)卫星是中国第一颗动力环境卫星,搭载的多普勒雷达和无线电定位组合系统(DORIS)作为HY-2主要定轨手段之一。本文较为详细介绍了HY-2多普勒雷达和无线电定位组合系统定轨技术流程和方法,并对其定轨结果进行了初步检验。     

Tracking laser radar for 3-D shape measurements of large industrialobjects based on time-of-flight laser rangefinding andposition-sensitive detection techniques

A tracking laser radar device is proposed for the 3-D measurement of the shapes of large industrial objects. The measuring system includes a servo-controlled measuring head and small reflectors attached to the object. The sensor consists of a tracking sensor, a pulsed time-of-flight rangefinder and angle encoders. The implementation of the tracking sensor and its test results are explained in detail. Tracking is accomplished by illuminating the reflectors of the target object and focusing the reflected light on the surface of a four-quadrant (4Q) position-sensitive detector, the signals of which are used to drive the servo motors of the measuring head. The test results show a tracking sensor resolution of about 0.003 mm (σ value) and bias of about ±0.1 mm when the distance and angle of the target reflector vary in the ranges 2-5 m and ±45°, respectively. The pointing accuracy of the tracking system was better than ±0.3 mm     

室内200 m虚拟基线测量方法的研究

为了解决手持式激光测距仪50m以上检测基准建立的问题,在50m高精度导轨上利用3个平面反射镜进行光路折叠,实现4倍光程倍增,搭建了室内200m基线。并将Leica TS15型全站仪视为检定基准,对基线长度进行标定。最后对Leica DISTOTM D510型手持式激光测距仪开展了50~200m测段的示值误差检定实验。实验结果表明: 室内基线系统的测量范围可拓宽至200m,示值误差检定结果的扩展不确定度为2.2mm(k=2),满足检定规程要求,有利于将长基线压缩至室内有限空间完成。     

卫星定位终端入栏检测算法的研究与实现

载有卫星定位的设备终端是否在设定范围内的检测方法,决定着电子围栏设计的成败。将分类思想用于此类检测,提出一种基于支持向量机的入栏检测算法。该算法依据卫星定位终端的定位数据特征选择合适的核函数;通过网格搜索法求取核函数及误差惩罚参数的值;视检测准确率高低不断调整确定最优阈值等几个环节来实现。用实测数据进行算法验证,入栏检测准确率可达80%～96%,远高于直接检测得到的43%～67% 的准确率,表明算法可靠有效,具有较高的实用价值。     

误差空间估计的卫星跟踪位置预测

为了提高光电跟踪设备进行卫星观测跟踪时的精度与平稳性,提出一种在跟踪过程中预测卫星位置的误差空间估计方法.该方法根据当前不完全有效与准确的实测数据,用动力学模型方法离线预测数据与离线预测误差表示卫星位置,在预测误差构成的误差空间中对其进行滤波与预测,再与离线预测数据合成以得到精度更高的卫星位置预测数据.实验结果表明,文中方法对卫星位置的预测数据精度比采用运动学模型的Kalman滤波方法高,在精度要求为1'的情况下,其能预测的时间范围比后者多25s以上,且误差随预测步长的增加,增长较缓慢.     

GPS在轨卫星原子钟性能评估

卫星钟在轨性能评估对于卫星钟差预报与系统完好性监测具有重要作用。利用国际GNSS服务组织发布的事后GPS精密卫星钟差数据,基于频率准确度、漂移率、万秒稳定度及天稳定度对GPS Block IIR、IIR-M、IIF与IIIA 4类卫星的星载钟性能进行评估。结果表明:1) GPS卫星钟的频率准确度与天漂移率分别在10^-13～10^-12量级与10^-15～10^-14量级;2) 星载铷钟的万秒稳定度与天稳定度分别可达10^-14与10^-15量级,比星载铯钟的同类指标高近一个数量级;3) 新型Block IIIA卫星的星载钟的天稳定度比另外3种类型卫星的星载钟的天稳定度更高,达到(3～5)×10^-15的水平;4) 无论对于不同系列卫星还是同一系列卫星,各星载钟之间均存在一定的性能差异,这种差异与卫星钟在轨运行时间长短无显著关系。     

环境一号卫星A/B星数据自动几何精校正设计研究

环境一号卫星A/B星是我国自主研制的小卫星星座,其在轨稳定运行近5年,并稳定获取了大量高质量的观测数据,实现对这些观测数据的几何精校正处理,对发挥环境星宏观、动态的生态环境监测有着重要意义。本文首先分析了环境一号卫星参数特点以及环境一号卫星2级数据(系统几何校正后的数据)的几何特点。基于此,设计了环境一号卫星各载荷总体几何精校正方法流程以及charge-coupled device(CCD)相机自动几何精校正方法。实际运行数据表明,该方法可以较好地实现环境一号卫星各载荷数据的自动几何精校正,环境一号卫星CCD相机自动几何精校正图像精度可达到2个像素以内,同星不同载荷图像之间自动匹配方法可以获取小于1个像素的图像匹配精度。     

The 3-D-3 Rangefinder and Depth of Field Indicator

A wander mark stereoscopic rangefinder using the normal eye separation as Its base length is described. It has two main controls: one carries a scale of ranges and could be coupled to the focusing mechanism of a camera lens; the other carries a scale af lens apertures and could be coupled to the stop setting mechanism of the lens. Three indicating marks appear In space at variable distances from the observer, to show the range and depth of field limits set by the controls. The optical system consists of an illuminated diapositlve, a collimating lens and three partially reflecting mirrors. It gives autamatic campensation for varying eye separations of different observers, is accurate and easy to use, even by spectacle wearers. The rangefinder affers advantages aver established methods of setting focus In both still and cine photography, particularly in low light and on moving subjects. Under these conditions the depth of field indication is a valuable asset.     

基于熵权法的卫星钟差预报研究

星载原子钟是全球导航卫星系统的核心设备之一,其性能及钟差预报精度直接决定着导航定位授时服务的精度。针对卫星钟差组合预报技术中子模型权值难以确定的问题,将熵权法引入到北斗卫星钟差组合预报中。对卫星钟差数据中的粗差、钟跳等异常值进行相频域组合探测,并使用滑动拉格朗日内插法进行修补,得到“干净”钟差序列。以灰色模型和二次多项式模型作为基础模型,构建基于信息熵这一新的评价指标的钟差组合模型,建立北斗卫星钟差熵权组合预报模型。使用武汉大学IGS数据中心发布的北斗精密钟差数据产品,分别进行了连续多天的短期预报和中长期预报试验,多天的平均试验结果验证了熵权组合模型在北斗卫星钟差预报精度和稳定性方面较传统组合模型均存在一定优势。