Using reference RFID tags for calibrating the estimated locations of construction materials

Effective automated tracking and locating of the thousands of materials on construction sites improve materials management and project performance. Utilizing location sensing technologies such as RFID, GPS, Ultra-wideband, infrared, and others help to achieve this objective; however, they generally provide imperfect data which results in lack of accuracy, precision and robustness. One possibility of improving the precision, accuracy, and robustness of such systems is the use of reference tags. In this paper active RFID tags are employed as reference points at known and fixed locations on a construction site and are used to calibrate the location estimation of other materials on the site. Materials on the site are uniquely attached with RFID tags and are subject to tracking. The basic principle of the calibration technique using reference points is to adjust the estimated location of neighboring tags by adding a unique offset vector to each individual tag location-estimation. In a two level approach, first the locations of all tags are estimated using a proximity method. Then a unique offset vector is calculated and added to each individual tag location to calibrate the estimated location in level 1. The offset vector is a weighted average of the shift-vectors between the observed and the true location of the reference tags. The weights are based on the relative distance between the observed location of the target tag and the reference tags. The experimental results show that calibrating the location estimates using reference tags can successfully deal with the challenges of a very noisy and dynamic environment and imperfect construction data and improve the precision of the estimated locations.     

The application of active radio frequency identification technology for tool tracking on construction job sites

Tool availability is a critical factor in the productivity of construction crews. In an effort to improve the efficiency of tracking tools and improve their availability, this research effort developed a tool tracking and inventory system which is also capable of storing operation and maintenance (O&M) data using commercially available active radio frequency identification (RFID) tags. With participation of two electrical construction firms, the system was tested on a number of construction jobsites. The project demonstrated that active RFID can be used to inventory small tools and store pertinent O&M data on the tools in construction environments despite metal interference and low temperatures. Economics, lack of standardization, and lack of direction and range data from the tags were identified as the most significant constraints limiting active RFID commercialization for tool tracking.     

基于标签技术的建筑施工安全管理移动终端设计与应用

对建筑施工现场安全管理模式进行充分调研,根据施工现场安全管理的特点及存在问题,应用区域管理理论和标签技术对施工现场安全管理模式进行优化。综合考虑射频识别（RFID）标签与二维码标签的性价比,结合施工现场实际情况和已有安全管理信息系统,设计并开发基于标签技术的建筑施工安全管理移动终端,并在武汉某建筑施工项目进行试用。用户反馈信息表明,该系统操作简便、实用性强,满足了建筑施工企业安全生产管理人员移动办公的需要,通过数据分析可全面掌握施工现场各区域安全状况,加强对高风险、多隐患区域的管理,有效减轻安全生产管理人员的工作负担,提高工作效率和安全管理水平     

A development of next generation intelligent construction liftcar toolkit for vertical material movement management

High-rise construction sites, especially those situated in spatially-constrained urban areas, have difficulties in timely delivery of materials. IT-driven management techniques can be further benefited from state-of-the-art devices such as Radio Frequency Identification (RFID) tags and Ubiquitous Sensor Networks (USN), which have resulted in notable achievements in automated logistics management at the construction sites. Based on those achievements, this research develops USN hardware toolkits for hoists, which aims to automate the vertical material delivery by sensing the material information and routing it automatically to the right place. The gathered information from the sensors can also be used for monitoring the overall status. To support the system, a hoist-mountable intelligent toolkit was developed. Its feasibility test was conducted by applying the implemented system to a test bed and then analyzing efficiency of the system and the toolkit.     

RFID indoor location identification for construction projects

This paper presents a low cost indoor location identification and material tracking methodology for construction projects using Ultra High Frequency (UHF) passive Radio Frequency Identification (RFID) technology. Onsite location aware information is an emerging area that focuses on automating delivery of spatial information pertinent to location of materials, workforce, and equipment. This spatial information can be used to derive knowledge about construction project status. A two-step algorithm is presented to automate the process of location estimation and material tracking in near-real-time. In this methodology, a number of passive RFID tags are distributed onsite where work is progressing, and a mobile RFID reader is carried by a worker onsite. Each passive RFID tag is deployed as a reference point with a known location (landmark) within a predefined zone. Reference tags of known locations are used to determine the location of the worker and eventually locate and track surrounding materials. The methodology uses Received Signal Strength Indicator (RSSI) for signal measurements. Two localization methods (triangulation and proximity) were used to identify the location of the worker. Testing this methodology was carried out on an actual construction jobsite, where five test beds were setup at different locations and within different construction time spans. In addition, one test bed was set up in a lab environment. The results presented in this study demonstrate the potential for a low-cost method for location estimation and material tracking of indoor construction. The results show a mean error of 1.0 m and 1.9 m for user location identification and material tracking using the triangulation method, respectively. The results also show a mean error of 1.9 m and 2.6 m for location identification of the worker and for material tracking using the proximity method, respectively. The proposed methodology detects the zones of worker and material location with 100% accuracy.     

Enhancing Cluster-based RFID Tag Localization using artificial neural networks and virtual reference tags

Construction sites are changing every day, which brings some difficulties for different contractors to do their tasks properly. One of the key points for all entities who work on the same site is the location of resources including materials, tools, and equipment. Therefore, the lack of an integrated localization system leads to an increase in the time wasted on searching for resources. In this research, a localization method based on Radio Frequency Identification (RFID) systems which does not need infrastructure is proposed to overcome this problem. This paper investigates the usage of active RFID technology for the localization of movable objects (e.g. components, equipment, and tools) equipped with RFID tags using handheld readers by extending a Cluster-based Movable Tag Localization (CMTL) technique which uses a k-Nearest Neighbor (k-NN) algorithm. CMTL uses a multidimensional clustering technique that considers signal pattern similarity between target and reference tags together with spatial distribution of reference tags for detecting the region where the target tag is located. The paper proposes applying an irregular bilinear interpolation method to form a grid of virtual reference tags within the selected cluster of real reference tags. Moreover, the proposed method uses artificial neural networks (ANNs) for positioning the target tag, as opposed to empirical weighted averaging formulas used in similar k-NN based methods. Comparative analysis is performed to quantify the improvement of the proposed method over similar k-NN-based methods using a simulation environment. A case study is performed to analyze the performance of the proposed method.     

RFID 3D location sensing algorithms

Effective monitoring of personnel movements, material locations, and construction equipment has always been a topic of concern in construction management. Radio Frequency Identification (RFID) technology has been proven to increase efficiency for staff and materials management. The objective of this study is to develop a Three-Dimensional (3D) location sensing algorithm using RFID technology to analyze the possible location of objects. To achieve this goal, this research first establishes an indoor wireless sensing network to collect Received Signal Strength Indication (RSSI). The distance between the antenna and target tag is calculated based on RSSI. The gradient decent method is then used to calculate the location of the electronic tag. The feasibility of this 3D positioning algorithm is verified using a real case. The experiment proves that the location sensing algorithm established in this study can gradually approach the actual location of the target tag. This research is one of the first studies for 3D location sensing with RFID application in the construction industry. The proposed RFID 3D sensing algorithm can be used to assist construction managers in locating the positions of relevant personnel, equipment, apparatus and materials, enhancing management efficiency and safety.     

Scenarios for applying RFID technology in construction project management

Radio Frequency Identification (RFID) technology has been widely applied in various areas such as retail, electronic transaction, logistic and supply chain management, scientific research, security, etc. It has brought about great benefits in these areas through improving real-time information visibility and traceability. However, a widespread application of RFID in the construction industry has not taken place. One possible reason is that construction practitioners may have not been fully informed of its potentials. This paper aims to investigate various scenarios that can illustrate the uses of RFID technology in construction project management. The research starts from a brief summary of recent developments of RFID technology in different industrial sectors including construction. 16 researchers were split into 3 groups to investigate how RFID can be used in the management of materials, men, and machinery (M³) for construction projects. Perspectives for future studies are proposed in order to fully realise the potentials. The research encourages a wider adoption of RFID technology in improving current PM practices. It also provides academia with a platform for further exploring the innovative uses of RFID technology in construction.     

RFID Enabled Knowledge‐Based Precast Construction Supply Chain

Radio frequency identification (RFID) helps improve supply chain efficiency by providing item‐level identification and real‐time information. Today, barcode continues to be the main identification technology for precast construction applications. In this research, we investigate the data‐driven mechanisms and benefits of utilizing RFID in knowledge‐based precast construction supply chains. With computer‐aided self‐learning capability, we simulate three models for manual‐, barcode‐, and RFID‐enabled precast construction supply chain. The results of 100 precast wall‐panel construction in a two‐echelon precast construction supply chain reveal that the knowledge‐based RFID system could generate 62.0% saving of operational costs, which is 29.0% higher than that of a barcode‐based system. As a result, the computer‐aided adaptive learning mechanism based on RFID is verifiable to improve the overall operational performance by reducing lead time, operational errors, and costs. Due to the lack of existing literature of data technology utilization in the precast construction industry, our findings in this research could improve the decision making regarding technology selection, as well as help with the operationalization of RFID and transformation to intelligent precast construction management in big data environment.     

Mobile passive Radio Frequency Identification (RFID) portal for automated and rapid control of Personal Protective Equipment (PPE) on construction sites

Although personnel entering a construction site are mandated to wear Personal Protective Equipment (PPE), hardly ever is PPE checked for accurateness, completeness, or whether its shelf-life has expired. Various commercially-existing automated identification (ID) and information technologies (IT) were used to design a mobile Radio Frequency Identification (RFID) portal for checking the PPE compliance of personnel. When such gates are positioned at the entrance or within construction sites and once low-cost passive RFID tags are embedded or attached to PPE, automatic site access, time recording, and completeness control can be performed. These improve the logistics of the existing compliance checking process and provide users with timely feedback. Results to “personnel entering a construction site” demonstrate how the safety process, especially the awareness among personnel wearing PPE, can be pro-actively managed and controlled. Data further suggests the limitations of the developed approach and its potential for gathering leading safety indicator data.     

RFID tracking implementation model for the technical trade and construction supply chains

The use of RFID (Radio Frequency Identification) tracking has increased considerably in supply chain management during the past ten years. Despite the large diffusion of the technology, the use of RFID tracking has remained scarce in the construction industry despite the intense research. The particular design and temporary operating sites of the construction supply chains delay the diffusion, because the best-known RFID tracking systems in other industries are mainly designed to support the retailers' processes. The particular supply chain structure of construction industry, demands different business logic to build and gain benefits of RFID tracking systems. This paper presents RFID tracking implementation model for technical trade and construction industries. The approach for building feasible model was Technology Acceptance Model. The model design is based on the research project, where 16 manufacturing and wholesaler companies of technical trade were involved, and survey where customers of these manufacturers and wholesalers were interviewed.     

基于RFID的预制混凝土构件生产智能管理系统设计与实现

预制混凝土构件是预制装配式建筑的核心部件,如何有效管理构件生产是预制装配式建筑产业化的关键问题之一。本文尝试将RFID标签嵌入预制混凝土构件中,实现生产全过程跟踪,并结合移动设备、互联网和数据库技术设计了预制混凝土构件的生产智能管理系统。系统对构件生产实施全程进度和质量管理,同时进行质量动态预警和生产计划调整.这有效地解决了因预制混凝土构件生产地点分散导致的质量和进度控制难题。     

A service-oriented integrated information framework for RFID/WSN-based intelligent construction supply chain management

As buildings are now taller, larger, and more complex, it has become increasingly more difficult to secure stockyards for materials and to resolve the surrounding traffic problems, creating an increased need for Just-In-Time (JIT) delivery. To support JIT delivery, it is necessary to build a framework that can facilitate the collection and share of information on construction components and material flow throughout the whole supply chain process. Many researchers have suggested that radio frequency identification (RFID) and wireless sensor network technologies could improve the effectiveness and efficiency of JIT management. In addition, service-oriented architecture (SOA), the services of which enable the interfacing of a heterogeneous system environment of parties involved in the supply chain management process, is suggested in the manufacturing industry as one of the solutions for effective collection and sharing of information in supply chain management. However, the construction industry has limits in applying the framework suggested in the manufacturing industry since the supply chain process in the construction industry is extremely dynamic due to frequent changes in the design and plans of construction projects. Therefore, the objective of this research is to develop a seamlessly integrated information management framework that can provide logistics information to project stakeholders for their decision making. The pilot test of the framework developed in this research showed that it can improve time efficiency by about 32% compared to the traditional supply chain management. The result of this research is expected to be utilized effectively as a basic framework to manage information in RFID/WSN based construction supply chain management (CSCM) environments.     

新形势下工程质量监督的发展机遇和应对策略

面对当前我国工程建设蓬勃发展的大好形势和机遇,在现有的建设法规管理体系下,广大质量监督人员需要进一步寻求完善的适合我国国情的建设工程质量监督方式方法.通过改变法制体系建设和监督方式,履行好政府监督的职能,探索出一条成熟的工程建设政府质量监督的道路.     

城市井盖智能化管理方法综述

近年来,由于城市中井盖管理不善,造成全国范围内各类伤人、损车事件频发,严重影响了市民的出行安全,造成不良的社会影响。本文针对目前我国城市井盖管理存在的问题进行分析、研究和探讨,在井盖安全防护、数字城管模式和RFID技术使用三种智能管理模式的基础上,提出了基于无线传感器的井盖丢失检测监管方法,整套系统具有较好的技术性能和应用价值。     

Accuracy assessment of ultra-wide band technology in locating dynamic resources in indoor scenarios

The use of Ultra-Wideband (UWB) technology in reporting the real-time location of resources (workers and equipment) is shown to be effective in improving the current safety monitoring practices. Since many site accidents occur when workers are struck by moving equipment or enter hazard-prone areas, it is important to evaluate the accuracy of the UWB RTLS in estimating the location of dynamic resources on construction sites. In this paper, the effects of variables, such as “speed” and “heading”, on the accuracy of the estimated location of dynamic tags are investigated. It is shown that the accuracy is inversely proportionate to the speed of the tag, the number of tags being tracked and the complexity of the path on which the tag is moving. A novel approach to defining “danger zones” on construction sites is also proposed through which the feasibility of using static tags to define the boundaries of forbidden areas on site is validated. The findings of this study indicate the applicability of UWB in locating dynamic resources on construction sites.     

前沿信息技术在装配式建筑建设管理中的应用研究

为解决装配式建筑建设管理过程中面临的设计信息缺乏互操作性、信息传递缺乏时效性、装配过程缺乏精准性以及大数据管理等难题,提出将建筑信息模型、P-BIM、无线射频识别技术、北斗定位技术、云技术应用于装配式建筑建设管理中。以期实现装配式建筑设计信息无缝对接,设计、生产、运输、装配全过程实时信息的可视化和实时监控管理,预制构件装配精准化,城市大规模装配式建筑群大数据的互通与管理,从而提升装配式建筑的建设管理水平。     

Managing construction information using RFID-based semantic contexts

Quick and correct information capturing, archival and retrieval in construction sites is essential to support project management. This paper presents a new methodology for managing construction document information using RFID-based semantic contexts. The methodology deploys four main tools for construction document archival and retrieval: (1) template document metadata modules that formulate document information; (2) semantic ontologies for indexing construction documents; (3) RFID framework for automatic identification of construction concepts; and (4) an ontological indexing mechanism to reason about ontological semantic relationships and infer applicable concepts for indexing. To demonstrate the role and contribution of the new proposed methodology, first a template for construction problem documents module has been constructed. Then, a new object-oriented Java-based prototype was developed to leverage RFIDs and OWL (Web Ontology Language)-based ontologies for reasoning about indexed construction concepts. Finally, a case study has been performed to validate the new methodology's capability of supporting users through available RFID information in the selection of construction concepts for archiving and retrieving related, stored documents from a relational corporate database of construction problems. The new methodology implementation shows a number of direct impacts such as the effectiveness of document archival and retrieval and the efficiency of fusing information. The new methodology is described in the paper, including findings obtained from the case study and a discussion of future research.     

Pose Estimation of Construction Materials Using Multiple ID Devices for Parts and Packets Unification

Abstract: A method for characterizing the pose (position and orientation) of large objects using multiple identification (ID) devices, such as radio‐frequency identification (RFID) devices, is proposed. Simultaneous management of construction materials and their data using ID devices for construction automation has been proposed. In this management scheme, workers or robots (1) acquire the ID of a device using an ID reader, (2) obtain construction material data using the ID, and (3) use the data to perform various tasks. In this scheme, the object pose is crucial because it can be changed by robots and workers who do not possess an ID reader or have not measured the pose previously. The proposed method uses the geometric relationship between the ID device attached to the object and the ID reader, and is based on the relationship between the relative displacements of multiple ID devices. The position and direction of each ID device and ID reader are measured with respect to the object and reference coordinate frames, respectively. Experimental results proved the feasibility of our proposed method.     

基于 Arena 仿真的建筑供应链投资 RFID成本分摊研究

实验表明 RFID 技术能为装配式建筑的管理带来极高的效率，然而 RFID 技术投资成本较高，目前尚不知如何在供 应链间进行成本分摊。以一个预制构件工厂和施工工地的供应链模型为基础，根据南京市某项目的预制外墙板供应链的实际 情况，利用 Arena 软件模拟供应链使用 RFID 技术和不使用 RFID 技术相应的总时间和失误情况，对比分析投资 RFID 技术 带来的收益。根据模拟结果计算出投资 RFID 技术的条件下工厂和工地承担该技术的成本分摊比率，结果表明投资 RFID 技 术显然受益，且定位到构件的概率在 50%以上时对供应链双方投资该技术的比率影响较小。