Hiam Khoury

WLAN Based User Position Tracking for Contextual Information Access in Indoor Construction Environments

This paper presents research that is investigating the requirements of an automated location-based methodology to rapidly identify and retrieve contextual project information on indoor and outdoor construction sites for supporting decision-making tasks of site personnel. The proposed approach to this retrieval task is the design and implementation of a dynamic user-viewpoint tracking scheme that can allow identification of construction entities visible in a users field of view at any given time and location. For outdoor applications, a geo-referencing based algorithm has been developed using Global Positioning System (GPS) receivers and magnetic orientation tracking devices to successfully track users dynamic viewpoint. For indoor applications, this research is studying the applicability of Wireless Local Area Networks (WLAN) for dynamic user position tracking. The objectives of this paper are to describe the overall methodology being designed as well as to describe the proof of concept experiments performed outdoors and indoors. The obtained results highlighted the potential of using location-aware technologies for rapidly detecting contextual objects in construction environments.

Evaluation of General-Purpose Construction Simulation and Visualization tools for Modeling and Animating AirSide Airport Operations

This paper illustrates how simulation modeling and visualization can be of substantial help in studying airside airport operations, and can greatly contribute in planning and designing construction operations at airports in a way that has the least impact on airside operations. The characteristic that distinguishes the current work is the capability to model and animate airside airport operations with high fidelity using general purpose discrete event simulation and visualization tools typically used to model and animate construction operations. The focus of the presented work is on evaluating the capabilities of state-of-the-art construction simulation and visualization tools in being able to accurately model and animate airside airport operations. The paper presents the simulation model and 3D animation of the airside operations at Detroit Metropolitan Wayne County Airport (DTW) in Romulus, Michigan. It also presents simultaneous modeling and visualization of operations in two different domains (i.e. airside operations and construction). The solution to the problem is described in detail using a simulation model developed in STROBOSCOPE and a 3D animation created using VITASCOPE. The obtained results highlight and prove that general-purpose tools, even if originally designed for specific domains, can be effective in studying operations involving the interaction of entities in multiple domains such as construction and airport operations.

Inertial-vision sensor fusion for pedestrian localization

The localization of an ambulatory individual, a.k.a. a pedestrian, is a quickly-developing domain with the potential to permeate into a variety of applications, as knowledge of an individuals location within an environment becomes ever-more useful. In order to automate the localization task, positioning modules are prime candidates for inclusion in a system. Such modules are expected to reduce both the effort and time incurred during the localization process while improving the accuracy and organization of the exchanged data. Building on and combining recent developments in the fields of step detection using inertial measurement units and structure from motion using a camera rig, the work presented in this paper is an implementation of a pedestrian localization system targeted specifically at infrastructure-less indoor localization. The inertial measurement unit and camera rigs are respectively attached to the mobile users foot and waist, and the collected data is processed by the localization module to obtain a current position. The focus of this paper is the implementation and preliminary testing of this localization modules components.

Structure of an extensible augmented reality framework for visualization of simulated construction processes

The presented work describes the recent research being conducted by the authors in the field of visualization of simulated construction processes. The underlying uncertainty involved in almost all construction operations makes it necessary to study and analyze the behavior of the acting resources in more detail and under different scenarios in order to come up with the most efficient method to perform a set of tasks and obtain the best possible result. Simulation and visualization of planned construction processes are powerful tools to achieve this objective. This paper focuses on the application of augmented reality (AR) for visualizing simulated construction processes in both outdoor and indoor environments and compares it to methods of visualizing modeled processes in pure virtual reality (VR). An AR framework and extensible class library are also introduced which can be used to verify and validate the results of simulation models and can be further applied to develop new AR systems

Evalutation of Agent-Based and Discrete-Event Simulation for Modeling Construction Earthmoving Operations

One of the most common operations to any construction project is earthwork. In fact, most, if not all, construction projects begin with earthwork activities. These activities require heavy equipment, are generally quite costly and consume a considerable amount of time. On another hand, the construction industry is becoming increasingly competitive over the years, whereby the need to continuously find ways to improve construction performance. In order to address the aforementioned adversities, this paper takes the initial steps and presents work targeted at efficiently managing logistics of earthwork operations in the construction field, namely cut and fill processes, and hauling activities. This dynamic and complex problem, which entails a lot of parameters and variables, is addressed in detail through creating two simulation models, a Discrete-Event Simulation (DES) model and an Agent-Based Simulation (ABS) one, using the multi-method simulation software AnyLogic 7.1. The purpose behind this study is twofold: (1) capturing and visualizing the interaction among the different resources or entities in an earthmoving operation and defining the weak links in order to improve the efficiency of such activities onsite, and (2) comparing DES and ABS approaches and evaluating the advantages and drawbacks of each when modeling earthmoving operations. Results of both approaches are presented and analyzed with regard to improving performance of earthmoving operations, followed by a discussion of the application and effectiveness of using each of the presented simulation approaches in modeling construction activities.

AUTOMATED GEOREFERENCED USER POSITION TRACKING FOR CONTEXTUAL INFORMATION RETRIEVAL ON CONSTRUCTION SITES

This paper presents research that is evaluating the capability of an automated location-based methodology in identifying and retrieving contextual project information on indoor and outdoor construction sites for supporting decision-making tasks of site personnel. Under this methodology, construction entities visible in a user’s field of view at any given time and location can be identified and cross-referenced with corresponding design and “as-built” data residing in construction databases and management information systems. The presented research attempts to achieve this by integrating outdoor positioning technologies together with location-based wireless technologies. Outdoor positioning techniques have been investigated and validated in other research efforts [1] [2] through the use of Global Positioning System (GPS) receivers and magnetic orientation tracking devices. For indoor environments, this paper aims at identifying Wireless Local Area Networks (WLAN) indoor positioning technique, a cheap, easily deployable and universally compatible location system for indoor use.

Simulation and visualization of air-side operations at Detroit Metropolitan Airport

This paper presents the simulation model and 3D animation of the airside operations at Detroit Metro Airport, Romulus, Michigan. The paper illustrates how simulation modeling and visualization can be of substantial help in studying airside airport operations, and by consequence can greatly contribute in planning and designing construction operations at airports in a way that has the least impact on airside operations. Given that construction processes modeling was studied effectively in previous research efforts, the presented example investigates only airport operations. The focus of the presented work is on evaluating the capabilities of state-of-the-art construction simulation and visualization tools in being able to accurately model and animate airside airport operations. The solution to the problem is described in detail using a simulation model developed in STROBOSCOPE and a 3D animation created using VITASCOPE

Modeling, Animating, and Optimizing On-Shore Wind Farm Construction Operations

AbstractRecently, wind energy has been greatly sought after because of the high price and diminishing quantity of fossil fuel resources. This necessitated the construction of wind farms. However, the on-shore wind farm construction process can be a very complicated task primarily because of the challenging location and topography of the remote rural sites where they are typically constructed. This paper takes the initial steps and presents work targeted at efficiently designing and planning the construction process of on-shore wind farms. For this purpose, a generic discrete event simulation (DES) model, illustrating the different construction stages from topographical surveying to wind tower assembly and erection and incorporating general resources data, was created. The developed model’s applicability was then tested for a specific site in Marjeyoun, Lebanon, where no wind farm has been constructed, and was verified and validated by animating all processes within a five-dimensional (5D) environment depi...

Evaluation of ultra-wideband technology for use in 3D locating systems

A high-powered (5 Watt peak power) ultra-wideband (UWB) ranging system was evaluated for use as the basis of a 3-Dimensional (3D) locating system by comparing tracking results to a ground truth system. The UWB ranging system is composed of five ranging radios. One radio is connected to a computer and the others communicate to it wirelessly. The distance between any two of the radios is determined using a time-of-flight (TOF) algorithm provided with the system from the manufacturer. Four of the radios were placed at known locations and the fifth radio was placed at an unknown location to be tracked. The distance from each of these four fixed radios to the fifth radio was continuously measured and different tracking algorithms were implemented to calculate the unknown radios 3D position in real-time. The algorithms tested utilized trilateration. multilateration, error minimization, and low-pass filtering. Position-versus-time data were obtained from each algorithm and compared to position-versus-time data obtained from a 3D ground truth locating system known to have an uncertainty of approximately 5 mm. Both moving and stationary tests were performed for each algorithm. During moving experiments, the tracked radio was moved along a predetermined path by an experimenter holding the radio while walking. During stationary experiments, the tracked radio remained at a single location while 1000 positions were measured by the various algorithms. The tests took place in an indoor laboratory environment which was free of obstruction in order to promote optimum performance of both the UWB and ground truth tracking systems. By analyzing the data from the UWB and ground truth systems, the error of the UWB systems 3D location measurement was expressed as a function of time.

An agent-based framework to study occupant multi-comfort level in office buildings

With the trend towards energy efficient buildings that diminish fossil fuel usage and carbon emissions, achieving high energy performance became a necessity. Allowing occupants to be actively involved during the design and operation phases of buildings is vital in fulfilling this goal without jeopardizing occupant satisfaction. Although different occupant behavior types were considered in prior research efforts, recent tools did not however examine simultaneously visual, thermal and acoustic comfort levels. This paper presents work targeted at efficiently studying occupant multi-comfort level using agent-based modeling with the ultimate aim of reducing energy consumption within academic buildings. The proposed model was capable of testing different parameters and variables affecting occupant behavior. Several scenarios were examined and statistical results demonstrated that the presence of different occupant behavior types is deemed necessary for a more realistic overall model, and the absence of windows results in an acoustic satisfaction with a decrease in (HVAC) use.