Yihai Fang

Case Study of BIM and Cloud–Enabled Real-Time RFID Indoor Localization for Construction Management Applications

AbstractIn the field of construction, indoor localization of mobile construction resources remains a universal challenge. Although discussions have focused on the tracking accuracy and affordability of indoor localization technologies, few efforts have focused on practical criteria such as ease of use, latency, and data visualization and remote sharing. To close this gap in knowledge, this study introduces a building information modeling (BIM) and cloud-enabled radio-frequency identification (RFID) localization system. The system consists of three main components: the passive RFID localization system, the BIM visualization system, and the cloud computing system. The proposed system is tested in a full-scale implementation on an actual construction site. The test was designed and conducted to evaluate the localization accuracy, data latency, and real-time data processing and visualization for remote monitoring. A comprehensive analysis is made of various practical issues based on the test results and panel...

Visualization, Information Modeling, and Simulation: Grand Challenges in the Construction Industry

AbstractWith the rapid advancement of sensing and computing technology and the wide adoption of mobile computing, the construction industry has faced a rise in the amount of information and data generated during the lifecycle of the construction project. To deal with a large variety of project data and information to support efficient and effective decision making, visualization, information modeling, and simulation (VIMS) has become critical in the development of capital facilities and infrastructures. The objective of this paper is to identify and investigate grand challenges in VIMS for the construction industry, to assist the academic and industry communities in establishing a future research agenda to solve VIMS challenges. In particular, 17 VIMS grand challenges were identified by an expert task force in the VIMS committee of the ASCE Computing and Information Technology Division, and then VIMS experts in the civil and construction areas from both academia and industry participated in a survey to as...

Effectiveness Analysis from a Cognitive Perspective for a Real-Time Safety Assistance System for Mobile Crane Lifting Operations

AbstractOperating a crane is a sophisticated job that not only requires extensive skills and experience, but more importantly a comprehensive understanding of the conditions of the crane and its surrounding environment throughout the operation. To enhance lift safety, various real-time assistance systems have been introduced to provide operators with critical information such as load moment and proximity to obstructions. However, previous efforts predominantly focused on the technology side, while the measurable impacts of such systems on actual lift performance from an operator cognitive perspective remain unclear. In order to ensure that an assistance system will improve rather than compromise the operator’s lifting safety and efficiency performance, this paper introduces a crane lift assistance system designed from a cognitive perspective. To reduce the overall cognitive load of crane operators, the proposed system aims to improve the situation awareness (SA) of the crane operator in two major stages o...

A Framework for Developing an As-built Virtual Environment to Advance Training of Crane Operators

Although hands-on practices are considered as the most effective training method for crane operators, they are always expensive and dangerous to be performed in the real world. As an alternative, virtual reality and simulator technology provide a close-to-reality experience in lifting operation while minimizing costs and hazards. However, the virtual environment in current training systems are static and designed ahead of time rather than representing an as-built construction site with its dynamic construction resource (workers, equipment, materials). Such drawback greatly limits the effectiveness of virtual training systems. To advance virtual training for crane operators, this research presents a framework towards constructing as-built virtual training environments by integrating Building Information Modeling (BIM) and real-time location tracking technology in a virtual environment. Implementing the proposed framework, a virtual training system for lifting tasks at an actual construction site was developed. The results of a pilot test show that such approach can effectively construct as-built work scenarios and potentially assess and improve operator proficiency in a virtual training environment.

Crane Load Positioning and Sway Monitoring Using an Inertial Measurement Unit

Crane operation is one of the most essential activities on construction sites. However, operating a crane is a sophisticated job which requires the operator to have extensive skills and experience, and most importantly a comprehensive understanding of crane motions. Besides typical crane motions such as boom slew, hoist, and extension, monitoring and controlling the position of the load is extremely important to avoid struck-by accidents caused by crane load, especially when the load swings as a result of wind and inertia. Although typical motions can be captured by some existing techniques, a reliable approach to position the load and monitor the load sway remains missing. This study proposes an orientation-based approach for tracking crane load position and monitoring load sway in daily lifting activities. This approach adopts an off-theshelf inertial measurement unit (IMU) module for measuring load orientation, and an efficient algorithm for converting orientation measurements to load positions. The proposed approach was tested in two load sway scenarios in a controlled lab environment. Test results indicate that the proposed approach correctly converted orientation measurements to accurate load positions and reconstructed the load sway trajectory in both linear and circular sway motions. Enabling continuously monitoring of crane load motion, this approach augments the crane motion information obtained by typical crane motion capturing systems. The findings in the research will advance the safety practices in crane lifting activities.

A Multi-user Virtual 3D Training Environment to Advance Collaboration Among Crane Operator and Ground Personnel in Blind Lifts

As one of the most expensive and frequently used resources, cranes play an essential role in the operation of activities on construction sites. They require certified operators whose knowledge of codes and regulations is essential for safe and productive lift tasks. Blind spots pose a significant issue for crane operators as they limit the crane operator’s field-of-view that potentially slows down execution of such tasks. Often collaboration between crane operators and ground personnel is limited and requires advanced communication techniques, such as radios, to resolve the limited visibility issue. Although visualization technology has been widely adopted in practice to enhance visibility, education and training programs related to cranes lack multi-user collaboration environments. This paper presents an approach towards developing a virtual training environment that allows multiple subjects to participate in lifting operations cooperatively. Through a 3D real-time immersive user visualization interface users are able to perform hands-on tasks such as operating cranes and directing blind lifts. In addition, geometry constraints and safety hazards are introduced to augment the simulation-fidelity of the virtual training environment. A test involving two users was conducted and the results show that the proposed approach can effectively simulate collaborative tasks in crane lifting operations. This study has potential to enhance the productivity and safety of crane lifting operations.

Real-Time 3D Crane Workspace Update Using a Hybrid Visualization Approach

AbstractCrane operators often face poor visibility and collision hazards during lifting operations. Dynamic three-dimensional (3D) modeling of the crane workspace helps to alleviate this by identif...

Measuring Operator’s Situation Awareness in Smart Operation of Cranes

Equipment operators play an integral role in the safe and efficiency operation of heavy equipment. They observe the environment, understand the situation, and make decisions and actions accordingly. Compared with other types of equipment, operating a crane is more sophisticated and mentally demanding, and thus crane operators are more vulnerable to human errors. Therefore, special considerations to mitigate operator errors should be taken when designing an operatorassistance system for construction cranes. With the goal of improving the operators’ situation awareness (SA) of safety risks, this research presents a technical framework and practical system architecture for an operator-assistance system by leveraging real-time motion sensing and 3D modeling of dynamic workspaces. An approach for evaluating operators’ SA was proposed to validate the effectiveness of the assistance system in actual lifting operations. Results in a series of field tests indicated that the prototype system improved the operators’ SA which resulted in an improved lift

A Knowledge-Based Cyber-Physical System (CPS) Architecture for Informed Decision Making in Construction

Most decision making in construction projects is accomplished by human beings based on manually collected information. This process is labor-intensive, error-prone, and heavily reliant on the knowledge and experience of the decision makers as well as the quality and reliability of the available information. Cyber-physical systems (CPS) offer the potential to transform traditional data collection approach and strengthen the coordination between cyber models and physical assets in a construction project. This paper describes a knowledge-based CPS architecture that aims at augmenting human decision making in construction. Domain knowledge, such as site policies, safety rules, and workflow logic, is elicited and compiled in an ontology-based knowledge hub. With the support of bi-directional cyber-physical communication, the knowledge hub inquiries relevant data from cyber models and physical assets, integrates realtime project data, and synthesizes context-specific information to facilitate human decision-making. This paper outlines the key challenges and technical requirements for creating the knowledge hub and its linkages with traditional CPS systems. It also presents two deployment scenarios in highway and building construction projects to demonstrate the realization a knowledge-based cyber-physical system and its potential in facilitating coordination and improving project performances in safety and efficiency.