Key technology of mine underground mobile positioning based on LiDAR and coded sequence pattern

Technologies of underground mobile positioning were proposed based on LiDAR data and coded sequence pattern landmarks for mine shafts and tunnels environment to meet the needs of fast and accurate positioning and navigation of equipments in the mine underground without satellite navigation signals. A coded sequence pattern was employed for automatic matching of 3D scans. The methods of SIFT feature, Otsu segmentation and fast hough transformation were described for the identification, positioning and interpretation of the coded sequence patterns, respectively. The POSIT model was presented for speeding up computation of the translation and rotation parameters of LiDAR point data, so as to achieve automatic 3D mapping of mine shafts and tunnels. The moving positioning experiment was applied to evaluating the accuracy of proposed pose estimation method from LiDAR scans and coded sequence pattern landmarks acquired in an indoor environment. The performance was evaluated using ground truth data of the indoor setting so as to measure derivations with six degrees of freedom.

Precise point positioning and its application in mining deformation monitoring

Precise point positioning (PPP)-based deformation monitoring scheme is presented for the use in mining deformation monitoring. Within the solutions of daily observation, outliers are detected and removed to avoid any potential misinterpretation of the results and then the deformation can be extracted by the coordinate differences between the two consecutive solutions. Meanwhile, because of the special location of a rover station in mining areas, the satellite geometry may be insufficient for a reasonable PPP solution, and the multipath impact an also be significant. Therefore, it is necessary to predict the satellite geometry before any daily observation. To evaluate the ability of extracting the deformation using the PPP-based method, various quality measures were introduced. The results of three datasets of the same station show that the precision of deformation monitored by PPP can reach up to cm level and even mm level.

Fuzzy adaptive Kalman filter for indoor mobile target positioning with INS/WSN integrated method

Pure inertial navigation system(INS) has divergent localization errors after a long time. In order to compensate the disadvantage, wireless sensor network(WSN) associated with the INS was applied to estimate the mobile target positioning. Taking traditional Kalman filter(KF) as the framework, the system equation of KF was established by the INS and the observation equation of position errors was built by the WSN. Meanwhile, the observation equation of velocity errors was established by the velocity difference between the INS and WSN, then the covariance matrix of Kalman filter measurement noise was adjusted with fuzzy inference system(FIS), and the fuzzy adaptive Kalman filter(FAKF) based on the INS/WSN was proposed. The simulation results show that the FAKF method has better accuracy and robustness than KF and EKF methods and shows good adaptive capacity with time-varying system noise. Finally, experimental results further prove that FAKF has the fast convergence error, in comparison with KF and EKF methods.

Application of Lightning Monitoring and Positioning Data in Investigation and Identification of Lightning Disaster in Inner Mongolia

The lightning current magnitude and other characteristics are important basic data of the lightning disaster investigation and identification. The characteristics of lightning monitoring and positioning system in Inner Mongolia were introduced and studied in the lightning accident analysis based on the lightning monitoring and positioning data of the lightning stroke accidents. The positioning error of lightning monitoring and positioning system was analyzed. The results showed that lightning current intensity and the position precision were very important data in the lightning disaster investigation. Finally, a variety of meteorological data should be applied in the lightning disaster investigation and identification.

Binocular Vision Positioning Method for Safety Monitoring of Solitary Elderly

In nowadays society,the safety of the elderly population is becoming a pressing concern,especially for those who live alone.There might be daily risks such as accidental falling or treatment attack on them.Aiming at these problems,indoor positioning could be a critical way to monitor their states.With the rapidly development of the imaging techniques,wearable and portable cameras are very popular,which could be set on human individual.And in view of the advantages of the visual positioning,the authors propose a binocular visual positioning algorithm to real-timely locate the elderly indoor.In this paper,the imaging model has been established with the corrected image data from the binocular camera;then feature extraction has been completed to provide reference to adjacent image matching based on the binary robust independent elementary feature(BRIEF)descriptor,finally the camera movement and the states of the elderly have been estimated to distinguish their falling risk.In the experiments,the real-sense D435i sensors were adopted as the binocular cameras to obtain indoor images,and three experimental scenarios have been carried out to test the proposed method.The results show that the proposed algorithm can effectively locate the elderly indoor and improve the real-time monitoring capability.

Offline handover location positioning for map matching of mobile probes

Handover location technology was employed for collecting road traffic information in a number of field projects, and the project results demonstrate that it is a supplementary and promising means of road traffic information collection for further traffic supervision and maintenance. Because handover location technology is one kind of pattern matching based location technologies, offiine handovex location positioning is an essential problem to be studied for successfully matching mobile probes on GIS map. Offline handover location positioning method involves two stages, handover location positioning respectively via two weighted models and an optimized model based on the intermediate results obtained in the first stage. A preliminary field test is conducted on a stretch of freeway in the inner suburban region in Beijing, and performance evaluation results show that the proposed method is superior to standard least square model in location accuracy and location precision, which is an effective method of offline handover location positioning.

Optimal Positioning of Mobile Platforms for Accurate Manipulation Operations

Many mobile robotics applications, especially in industrial environments, require the robot to perform safe navigation and then reach the goal with a high precision. In this research work, the objective is to analyze the appropriateness of autonomous natural navigation strategies for mobile manipulation tasks. The system must position itself in a realistic map, follow a path closely and then achieve an accurate positioning in the destination point in order to be able to perform the manipulation, inspection or pick task efficiently. Autonomous navigation is not able to fulfill the accuracy required by some of the jobs so that a second positioning system using vision is proposed in this paper. The experiments show that localization systems have, on average, an error greater than a decimetre and how an additional positioning system can reduce it to a few millimetres.

Communication-based positioning systems:past,present and prospects

This paper reviews positioning systems in the context of communication systems. First, the basic positioning technique is described for location based ser- vice （LBS） in mobile communication systems. Then the high integrity global posi- tioning system （iGPS） is introduced in terms of aspects of what it is and how the low Earth orbit （LEO） Iridium telecommunication satellites enhance the global posi- tioning system （GPS）. Emphasis is on the Chinese Area Positioning System （CAPS） which is mainly based on commercial geostationary （GEO） communication satellites, including decommissioned GEO and inclined geosynchronous communication satel- lites. Characterized by its low cost, high flexibility, wide-area coverage and ample frequency resources, a distinctive feature of CAPS is that its navigation messages are generated on the ground, then uploaded to and forwarded by the communication satellites. Fundamental principles and key technologies applied in the construction of CAPS are presented in detail from the CAPS validation phase to its experimental system setup. A prospective view of CAPS has concluded it to be a seamless, high ac- curacy, large capacity navigation and communication system which can be achieved by expanding it world wide and enhancing it with LEO satellites and mobile base stations. Hence, this system is a potential candidate for the next generation of radio navigation after GPS.

Clock-based RAIM method and its application in GPS receiver positioning

Because the signals of global positioning system （GPS） satellites are susceptible to obstructions in urban environment with many high buildings around, the number of GPS useful satellites is usually less than six. In this case, the receiver autonomous integrity monitoring （RAIM） method earmot exclude faulty satellite. In order to improve the performance of RAIM method and obtain the reliable positioning results with five satellites, the series of receiver clock bias （RCB） is regarded as one useful satellite and used to aid RAIM method. From the point of nonlinear series, a grey-Markov model for predicting the RCB series based on grey theory and Markov chain is presented. And then the model is used for aiding RAIM method in order to exclude faulty satellite. Experimental results demonstrate that the prediction model is fit for predicting the RCB series, and with the clock-based RAIM method the faulty satellite can be correctly excluded and the positioning precision of GPS receiver can be improved for the case where there are only five useful satellites.

Managing crawling-type gastric adenocarcinoma with endoscopic techniques and postoperative monitoring

Crawling-type gastric adenocarcinoma is a rare subtype of gastric cancer with diagnostic and therapeutic challenges due to its flat,ill-defined lesions.Advanced diagnostic techniques,such as narrow-band imaging and linear endoscopic ultrasonography,improve detection,but endoscopic submucosal dissection poses a risk of incomplete resection.Despite negative resection margins,vigilant postoperative monitoring is crucial due to the potential for recurrence.This letter highlights the importance of refined diagnostic criteria,individualized treatment approaches,and continuous follow-up to optimize management of this unique gastric cancer subtype.

Hybrid Uplink-Time Difference of Arrival and Assisted-GPS Positioning Technique

A hybrid positioning system is merely one in which multiple systems are used for positioning purposes. This virtually always, though not necessarily, includes Global Positioning System (GPS) as it is the only global positioning network currently. Combination of mobile network and GPS positioning techniques provide a higher accuracy of mobile location than positions based on a standalone GPS or mobile network based positions. High accuracy of mobile position is mainly essential for emergency, military and many other location based services such as productivity enhancement, entertainment, position-based advertising, navigation, asset management and geographic information access. Assisted GPS, also known as A-GPS or AGPS, enhances the performance of the standard GPS in devices connected to the cellular network. This paper introduces a new hybrid technique for mobile location determination utilizing Universal Mobile Telecommunication System (UMTS) network, Mobile Station (MS) and GPS positioning characteristics. Different positioning techniques are chosen according to positioning parameters. The minimum required number of UMTS base stations, location measurement units and GPS satellites are calculated in this paper. The required number of GPS satellites is reduced from four satellites to three ones while using three dimension positioning and from three satellites to two ones at two dimension positioning. Moreover, MS receiver main functions including both network and GPS received paths to achieve output assisted data are discussed. In this paper many drawbacks such as indoor positioning, receiver high power consumption, delay in first time to fix position, low position accuracy as well as large number of required satellites and base stations are improved.

Positioning in Dynamic Testing of Slender Bridges

The positioning combined with multi-functioning and interactive mechanics in dynamic testing of slender bridges are treated in present paper. The approach takes into account multiple functions in dynamic testing of slender bridges constructed of thin-walled structural members with their hierarchical configuration. Theoretical, numerical and experimental in situ assessments of the problem are presented. Some results of the application in situ are submitted.

Quality monitoring of real-time GNSS precise positioning service system

The Real-Time Global Navigation Satellite System(GNSS)Precise Positioning Service(RTPPS)is recognized as the most promising system by providing precise satellite orbit and clock correc-tions for users to achieve centimeter-level positioning with a stand-alone receiver in real-time.Although the products are available with high accuracy almost all the time,they may occasionally suffer from unexpected significant biases,which consequently degrades the positioning perfor-mance.Therefore,quality monitoring at the system-level has become more and more crucial for providing a reliable GNSS service.In this paper,we propose a method for the monitoring of realtime satellite orbit and clock products using a monitoring station network based on the Quality Control(QC)theory.The satellites with possible biases are first detected based on the outliers identified by Precise Point Positioning(PPP)in the monitoring station network.Then,the corresponding orbit and clock parameters with temporal constraints are introduced and esti-mated through the sequential Least Square(LS)estimator and the corresponding Instantaneous User Range Errors(IUREs)can be determined.A quality indicator is calculated based on the IUREs in the monitoring network and compared with a pre-defined threshold.The quality monitoring method is experimentally evaluated by monitoring the real-time orbit and clock products generated by GeoForschungsZentrum(GFZ),Potsdam.The results confirm that the problematic satellites can be detected accurately and effectively with missed detection rate 4×10^(-6) and false alarm rate 1:2×10^(-5).Considering the quality alarms,the PPP results in terms of RMS of positioning differences with respect to the International GNSS Service(IGS)weekly solution in the north,east and up directions can be improved by 12%,10%and 27%,respectively.

Integrity monitoring scheme for single-epoch GNSS PPP-RTK positioning

Integrity monitoring for precise point positioning is critical for safety-related applications.With the increasing demands of high-accuracy autonomous navigation for unmanned ground and aerial vehicles,the integrity monitoring method of high-precision positioning has become an essential requirement.While high precision Global Navigation Satellite Systems(GNSS)positioning is widely used in such applications,there are still many difculties in the integrity monitoring method for the multi-frequency multi-GNSS undiferenced and uncombined Precise Point Positioning(PPP).The main difculties are caused by using the measurements of multiple epochs in PPP.Based on the baseline Multiple Hypothesis Solution Separation(MHSS)Advanced Receiver Autonomous Integrity Monitoring(ARAIM)algorithm,this paper discusses the feasibility of the pseudorange-based baseline ARAIM method on the single-epoch PPP based on Real-Time Kinematic(RTK)networks(PPP-RTK)framework to overcome these difculties.In addition,a new scheme is proposed to transfer the conventional PPP process into the single-epoch PPP-RTK framework.The simulation results using the proposed model are analyzed in this study.The Protection Levels(PLs)estimated by PPP Wide-lane Ambiguity Resolution(PPP-WAR)model with regional corrections can reach the meter level and the PLs estimated by PPP Ambiguity Resolution(PPP-AR)and PPP-RTK models are usually the sub-meter level.Given a horizontal Alert Limit(AL)of 1.5 m,the global coverage of availability above 99.9%for PPP-WAR,PPP-AR,and PPP-RTK can reach 92.6%,99.4%,and 99.7%respectively.The results using real kinematic data also show that tight PLs can be achieved when the observation conditions are good.

Position Optimization for Mobile Relay Communications with Constrained Energy over a Whole Horizontal Plane

This paper concerns the position optimization problem of a mobile relay over a whole horizontal plane.This problem is important because the position of a mobile relay directly affects the end-to-end performance,e.g.,reliability,connectivity,and data rate.In this paper,we propose a new position optimization scheme of a mobile relay over a whole horizontal plane based on the one-bit feedback information from the destination node,which improves the performance over the prior scheme whose position of the mobile relay is optimized over a fixed orbit.In the proposed scheme,the mobile relay is equipped with merely one single onboard antenna.Moreover,no prior information about the positions of both the source node and the destination node is required.Thus,the proposed scheme can work at low network resources scenario,which is particularly suitable for mobile relay communication with constrained energy,e.g.,the communications in a disaster area where the infrastructure is heavily damaged,volcano monitoring,and wireless powered communication networking.According to the characteristics of the proposed scheme,we further design two heuristic implementations to calculate the optimal position of a mobile relay over a whole horizontal plane.The first implementation has better steady performance whereas the second implementation has better convergence speed.We implement the proposed scheme and conduct an extensive performance comparison between the proposed scheme and prior schemes to verify the advantages of the proposed scheme.

家庭功能和积极应对方式对孤独症谱系障碍儿童父母养育倦怠的影响

目的 分析家庭功能和积极应对方式对孤独症谱系障碍(ASD)儿童父母养育倦怠的影响。方法 采用便利抽样法,选取2022年6月至2023年5月在东莞市妇幼保健院确诊的ASD儿童的父母60名作为试验组,选取健康正常儿童的父母60名作为对照组,比较两组家庭功能问题;Pearson相关分析试验组家庭功能、父母养育倦怠、积极应对方式的关系;中介效应检验采用Bootstrap方法;通过多元线性回归分析父母养育倦怠的影响因素。结果 两组在家庭功能评定量表各维度、简易应对方式量表(积极应对)、养育倦怠量表、孤独症行为量表、儿童孤独症评定量表、日常生活活动能力量表、儿童发育行为评估量表方面比较,差异有统计学意义(P <0.05)。Pearson相关分析结果显示,家庭功能、积极应对方式与父母养育倦怠之间存在显著的负相关(r=-0.186、-0.898,P=0.006、0.004),家庭功能与积极应对方式之间存在显著的正相关(r=0.048,P=0.005)。积极应对方式在家庭总体功能与养育倦怠中起部分中介作用,间接效应占总效应的37.98%。多元线性回归分析,家庭功能评定量表、简易应对方式量表、孤独症行为量表、儿童孤独症评定量表、日常生活活动能力量表、儿童发育行为评估量表评分是ASD患儿父母养育倦怠的影响因素(P <0.05)。结论 家庭功能和积极应对方式在ASD儿童父母养育倦怠中起重要作用。

Locating Global System for Mobile Communication(GSM)Base Stations Using Geographic Information System(GIS)

The global system for mobile communication(GSM)is planned to meet the needs of the whole subscribers.The number of subscribers increased as the population increased due to the acceptance of GSM services by the subscribers.Thus,there should be a way to monitor base stations that will meet the increasing demand of subscribers in any area as a population surge will lead to more subscriptions.This will allow GSM network operators to serve their subscribers better and ease network congestion.This work presents a review of mobile evolution from the first generation to the fifth generation.A review of global positioning system(GPS)technology and its applications to geographic information systems(GIS)was done.The coordinates of these base stations were taken using a GPS device.These base station coordinates were then exported to QGIS for the design of the map.Thereafter,the output map was then integrated into the website.The discussions on the results followed and some useful suggestions given will go a long way to help the operators of GSM in Nigeria and in general.If the propositions given are adhered to,it will go a long way to help the operators reduce congestion on their network and thereby increase the satisfaction of the subscribers.

煤矿微震监测与定位系统的研究与验证

针对我国采矿业不断发展,矿震事件不断发生,设计出了一种煤矿监测与定位系统,该系统以STM32F407为主控芯片,通过控制各个模块实现微震源的监测与定位,其中对到达时间差算法(TDOA)进行改进,提出了基于到达时间差的改进布谷鸟搜索算法(TDOA-ICS)的微震定位算法。经过实验验证,TDOA-ICS算法相较于传统TDOA算法定位精度更高,稳定性更强,对于煤矿安全设备研究具有重要的现实意义。

强流脉冲束流位置探测器标定技术

电子直线感应加速器性能提升对束流探测器提出了高精度测量要求,由此不仅要求高精度的探测器设计装配技术,而且也要求探测器的准确标定。从强流脉冲束流位置探测器测量原理出发,从理论和实验两方面开展强流脉冲束流位置探测器标定技术研究。在理论上采用解析方法,分析了不同的计算处理方法和标定方法的标定效果,提出了特征平面标定,在建立的位置标定系统上,对用于多脉冲电子直线感应加速器的No.23电阻环进行了标定实验研究,实验结果验证了理论分析结果,根据理论和实验研究结果,确定了强流脉冲束流位置探测器标定方法。

地月空间基础设施体系架构与发展设想

建设地月空间基础设施,为人类在地月空间的活动提供基础性、通用性的通信、导航、监测等服务,既可满足中国后续月球探测国家重大工程任务需求,同时可以加速推进地月空间航天产业发展,对于推动中国科技强国、航天强国建设具有重大的战略意义。在阐明地月空间基础设施概念、分析研判国内外发展现状的基础上,紧密围绕重大工程和航天产业持续性发展需求,提出地月空间基础设施体系架构设想,明确系统服务、系统组成、“云-域-端”网络体系以及内部和用户接口体系。最后以分阶段逐步建成技术先进、布局合理的地月空间基础设施,提供自主开放、安全可靠、长期连续稳定运行的通用化服务为目标,提出发展展望和发展建议,为中国地月空间基础设施发展建设规划提供参考。