针对在全球卫星导航系统(GNSS)及超宽带(UWB)组合的室内外无缝定位系统中,室内定位基准取决于UWB基站的位置基准,与GNSS通常所用的大地坐标系不一致的问题,提出一种基站位置估计方法:利用携带GNSS接收机和UWB标签的移动站来估计室内UWB基站位置;以移动站获取的GNSS坐标和UWB测距信息作为观测量,采用扩展卡尔曼滤波(EKF)法解算UWB基站坐标,使UWB定位基准自然统一到大地坐标系下.实验结果表明:该方法具有较好的估计效果;UWB基站无需提前布设,自然统一到大地坐标系下.

基于二维编码标尺的数字水准测量系统已经提出好几年了,但在实用化和产业化上遇到了 一些问题.提出一种改进的二维编码设计方案,改进后的新编码方案保留了圆形精码和数字码,增加了字母码;圆形码中心表达精定位,由数字码和字母码表达粗定位,其中数字码用于中远距离、字母码用于近距离粗定位.测量时图像传感器会捕获到包含标尺三类编码的图像,利用圆心定位算法精确计算圆形码圆心在图像中像素位置,进而确定圆心与望远镜水平中丝在图像上的像素差;同时引入卷积神经网络算法识别圆形码两侧的字母码或数字码用以确定相应圆形码的实际高度;最后将多个圆形码确定的视线高度取平均值作为标尺读数.利用搭载面阵CMOS传感器的水准仪原型机在室外对改进后编码标尺进行测试,实验结果表明,可以实现2～100 m范围内的有效测量,特别是在2～60 m范围内可以获得较为理想的测量精度,证明了新编码标尺是一种可行的设计方案,具有产业化价值.

Prefabricated concrete (PC) components require curing at the specific environment after being cast for the concrete to harden to the required levels over a certain period of time. Currently, steam curing is used as the major technique in concrete production. However, this method is highly energy consuming and requires large amounts of fossil fuels. Analysis of thermal process parameters in PC curing and thermal properties of phase change materials (PCMs), developed by the research team at Beijing University of Technology for the greenhouse applications, resulted in the development of the conceptual design of passive solar PC steam curing buildings with on-wall PCM heat storage. The process of selection of the PCM for installation on the inner surface of the main sun-facing wall of solar passive curing buildings is described. The selection is the result of the evaluation of suitable PCMs using the simultaneous process of transient energy consumption simulation with the deployment of EnergyPlus software and one-dimensional unsteady heat transfer modelling across the thickness of the thermal storage. The EnergyPlus simulations were calibrated against experimental data obtained in the curing building in Hebei Province, China. Theoretical simulations for such the building demonstrate that a GH-37 PCM panel with a thickness of 50 mm is suitable for such the application. The temperature range of phase transition for the GH-37 PCM is between 37.4 and 43.5 degrees C with latent heat equal to 227.5 kJ/kg. Compared to the same case but without PCM, the monthly and nocturnal average temperature of the inner surface of the main sun-facing wall increases by 1.3 degrees C and 2.7 degrees C, respectively. The heating load is reduced by 6.4, 5.8, 3.4 and 2.9 GJ in spring, autumn, summer and winter periods, respectively. The amount of annual steam consumption is reduced by 4.7%. (C) 2020 Elsevier Ltd. All rights reserved.Y

针对超宽带(UWB)定位过程中,易出现基站距离信息不足无法准确定位的问题,提出1种适用于UWB定位的集中式解算方法:介绍3种UWB定位估计算法并比较其优缺点,然后分析并推导2种定位模型的解算方程,最后提出协作式定位解算策略.实验结果表明,在基站距离信息不足的情况下,采用协作定位模型仍然能解算出坐标,而相比单点定位方法,精度由厘米级下降到分米级.

野外基线是测绘科学技术领域中特殊的长度实物标准,可用来检定全站仪等光电测距仪的加、乘常数,为确保检定结果的真实、准确、可靠,定期进行野外基线的溯源是必不可少的.目前我国主要采用24 m因瓦尺或高精度光电测距仪2种方法实现野外基线的溯源,已有大量实验事实表明,我国野外基线的量值传递与国外仍存在着不一致的问题.随着我国制造业的快速发展和“中国制造2025”的提出,传统的野外基线溯源技术很难满足越来越高的精度要求,迫切地需要实现野外基线精密测距.结合国内外研究现状,对光干涉法、24 m因瓦尺法和高精度光电测距法进行总结,深入分析了3种野外基线溯源方式的优缺点.最后,对我国未来的基线场建设提出了一些思考与建议.

目前,使用精密测距仪μ-base测量野外基线时,国内测绘单位测量气象元素往往采用求测站和镜站平均值的方法.为提高测距准确度,结合推导出的μ-base测距仪气象改正公式并依据误差传播定律,对气象代表性误差进行分析,设计了环境参数自动采集系统,在基线沿线布设温湿度、气压传感器,精确采集气象参数.对于普遍采用分段线性插值计算测线温度的方法,提出一种基于径向基神经网络的温度曲线逼近方法.结果表明,曲线整体的平滑性和曲率渐变性较好,更加符合地表温度分布规律,具有良好的效果.

Outdoor baseline is the special length standard in the field of surveying and mapping, it can be used to verify the addition and multiplication constants of the total station and other photoelectric rangefinders. In order to ensure the authenticity, accuracy and reliability of verification results, conducting outdoor baseline traceability periodically is essential. At present, direct measurement by 24m invar tape or high precision electro-optical measurement is mainly used to achieve the traceability of outdoor baseline in China. Based on Shenyang baseline field, high precision rangefinder μ-base, 24m invar tape and high precision GNSS receivers are used for comparison experiments, and the experimental results are analyzed.

由于野外基线沿线布设的温度传感器网络长时间暴露在室外,受自然条件的影响,传感器易出现数据缺失、数据异常等故障问题.为保证基线校准精度,结合μ-base测距仪的大气折射率修正公式并依据误差传播定律,对温度传感器最大允许测量误差进行分析.为及时、准确地排查出故障设备,针对整个传感器网络的时空特性,结合样本熵的方法,提出了一种改进型粒子滤波算法.为验证改进算法的精度及性能,基于实测数据进行实验验证及仿真分析.对于无故障数据,当粒子滤波阈值设置为1.7℃时,改进型粒子滤波算法检测的准确率在92％左右,便于排除故障设备,维护温度传感器网络的正常运转.

Measurement and control software of super-station is the core part of super-station and it is also the important part of realizing super-station function. Aiming at the functional characteristics of the super-station, this paper designs the measurement and control software of the super-station and implements it by programming, focusing on the three aspects of the design requirements of the super-station. The interface connection between the measurement and control software and each unit of the super-station is solved in the design. In the aspect of the realization of measurement and control function, the design scheme and flow chart are defined, and the control instruction analysis and interface design are carried out. In the database module, by transplanting FATFS file system, the operation of adding, deleting, modifying and checking measurement data can be realized in the form of files. Finally, we summarize the main work and shortcomings of the design.

This paper introduces in detail methods about calibration length baseline based on mu-base distance meter, and errors in the calculation of oblique distance model; the measurement of meteorological parameters and the correction of height difference are analyzed quantitatively by means of equation derivation. Through the calibration results of mu-base and invar tape, systematic differences between the two measurement methods were found out at the Yellow River Embankment Length Baseline in Zhengzhou. Based on a TS30 total station instrument with stable performance, according to the calculation results of "analytical method" and "comparative method", the accuracy of the two calibration results between mu-base and invar tape is compared and evaluated. In the end, some suggestions to improve the accuracy of using mu-base to calibrate length baseline are given.

One challenge to the precast concrete (PC) building industry lies in the ability of producing PC component energy-efficiently. Phase change material (PCM) to store thermal energy offer a considerably higher energy density at a nearly constant temperature level. Here in this work, we proposed a design of solar energy-streaming curing building using GH series PCM as the inner surface of the wall. To screen the most suitable PCM material, we used Energy Plus software to simulate the inner surface temperature of the wall for a whole year and heat release of the wall. Based on the analyzing data, GH-33 was selected as the optimal PCM and a PCM wall thickness of 50 mm was determined. This study provided a good reference for energy-saving PC curing technology.

为解决基于视觉方法测量柔性结构模态测量范围小、无法同时测量大型柔性结构纵深方向多个节点的振动情况的问题,提出基于单目红外的远距离多测点振动测量方法.在单红外相机的基础上,加装带通滤光片、红外LED等设备构成测量系统.利用离焦成像的原理对不同距离段内的LED灯组同时成像,对测量结果使用卡尔曼滤波平滑减小误差,滤波后定位精度为0.5 mm,重复性定位精度优于0.2 mm.通过在不同距离布设不锈钢尺模拟大型柔性结构,测量及实验计算结果与固有频率理论值进行比较相对误差最小为2.22％,计算过程中,滤波后数据有效地排除了干扰峰值.实验结果表明,所提测量方法简单有效,可应用于大型柔性结构模态检测等领域.

圆心检测中,圆的边缘缺损会影响圆心检测的精度.霍夫圆圆心检测具有良好的稳定性,但是精度稍低;最小二乘圆拟合,具有较高的精度,但是易受噪声点的干扰.针对这种情况,本文提出了一种基于霍夫圆的亚像素缺损圆圆心检测方法.先利用霍夫圆检测出粗略圆心坐标及半径,再利用轮廓检测技术提取出所有轮廓点的坐标,并根据霍夫圆检测出圆心及半径对轮廓坐标进行筛选,保留在圆上的轮廓坐标,并利用这些轮廓点坐标进行最小二乘圆拟合求出圆心.实验结果表明,该方法适用性较广,简单可靠,精度高.

在对圆形目标进行图像处理以实现精密测量的各种任务中,圆心定位的精度直接决定了测量结果的精度.目前,成熟的圆心定位算法包括重心法、Hough变换法、高斯拟合法、圆拟合法以及椭圆拟合法等.这些常用算法各具优缺点,因此有不同的适用场景.本文提出了一种新的研究思路,利用高斯过程模型解决圆心定位的问题,并且提出了分别基于标准圆和椭圆方程的高斯过程圆心定位算法.实验结果表明,高斯过程标准圆中心定位算法与圆拟合算法的精度相当,而且在残缺圆的圆心定位中抗噪能力更好,精度更高;高斯过程椭圆中心定位算法比椭圆拟合法的抗噪能力更强,精度更高.

When using photogrammetric method to measure axial forgings, it is impossible to measure the points' coordinates of the same section or spiral line, so the conventional method to evaluate the cylindricity error can't be used. In this paper, a cylindricity error evaluation algorithm based on mechanical thinking is proposed. The measurement points which are near the same shaft parts are divided into a group and projected onto the fitting surface of the bottom of shaft parts. Each group of projected points can do ellipse fitting to obtained the center coordinates. The initial axis equation is obtained through two sets of point coordinates which are the mean value of the coordinates obtained on the bottom surface. Different from grid method and genetic algorithm, the optimal axis equation is obtained by adjusting the axis equation in the corresponding direction based on the mechanical thought and the operation speed is accelerated by changing step length. Experimental results show that this method is equivalent to the traditional measurement method, besides it's simple and efficient without tedious process on measuring the points.

目的 圆形标志目前正广泛地应用于各类视觉测量系统,其圆心定位精度决定了测量系统的测量精度.当相机主光轴与标志表面不平行时,圆被映射为椭圆,圆心位置计算产生偏差.光轴与标志表面夹角较大或标志较大等情况下会产生较大的偏心差进而严重影响系统测量精度.为此,提出一种基于三同心圆圆形标志的投影偏心差补偿算法.方法 算法基于三同心圆的圆形标志设计,根据3组椭圆拟合中心坐标解算偏心差模型进行计算补偿.结果 针对圆形标志偏心差问题,同心圆补偿算法取得良好效果,有效提升了圆形标志定位精度.仿真结果表明,在拍摄角度、拍摄距离、圆形标志大小不同的情况下,偏心差在像素量级,补偿后偏心差在10-11像素量级.实物实验结果表明,若设计有直径分别为6 cm,12 cm,18 cm的三同心圆标志,经解算补偿结果较以往两同心圆算法精度提高一倍,偏心差值减小80％,测量误差在0.1 mm左右.结论 本文提出了一种新的偏心差补偿算法,利用三同心圆标志增加约束解算偏心差.与以往偏心差补偿算法相比,此方法精度更高,且无需预先平差解算相机与目标的距离、拍摄角等参数,仅需要知道标志圆形半径比例及椭圆中心坐标即可计算补偿,具有很高的实用性,可用于改善基于非编码标志点的深度像匹配、基于圆形标志点的全自动相机标定方法、视觉导航定位等应用中.

Aimming at the problem that the current radio wave propagation model is not adapt to FM broadcasting signals, this paper studied on the propagation model and ranging method of FM broadcasting signals under complex environment: the existing propagation models were analyzed for the system identification of multi-direction FM broadcasting signals, and a reasonable propagation model of FM broadcasting signals was got, then it could be shown that within a certain distance the propagation loss of FM signal and the distance have a stable function relationship.The result could provide a reference for the related research on navigation and positioning, the spectrum detection and management, the passive radar and network construction of FM broadcasting signals.

针对卫星定位信号易受遮挡和干扰等因素影响,导致定位误差较大的问题,提出一种利用数字音频广播信号定位方法:首先分析调频频段数字音频广播的信号帧结构,研究定位参量的提取方法,发现无线子帧的信标符号是一种由伪随机序列生成的独立调制的OFDM符号,结构简单且适用于伪码测距;进一步分析包含接收机钟差和观测噪声的伪距模型,利用多站平面测距定位法实现定位。实验结果表明,定位精度可达10m以内。

Conventional calibration method of boresight angles is depending on manual procedures of measuring the overall strip homologous feature discrepancy to determine the boresight angles.The accurate positions of the homologous features in overall strips are unrealistic to locate.In addition,the existence of eye collimation error also reduces the calibration accuracy,thus it requires a great mount of iterative computation to approach the ideal values of the boresight angles.Thus a target of assisting calibrating the boresight angles was designed to solve the problem of obtaining homologous features.A description of its design principle and structure was present firstly.Then several scale models were fabricated for the semi-simulation ground scanning test to analyse the usability of the calibration target preliminary.Finally,two prototype size calibration targets were fabricated for the aircraft flight test to demonstrate the usability in advance.The research results show that the design of the calibration target is rational.