Semiha Ergan

Evaluation of Different Features for Matching Point Clouds to Building Information Models

AbstractWith the increased usage of building information models (BIMs) during construction, has BIM become a medium for delivering as-built building information. It is important to maintain accurate and up-to-date information stored in a BIM so that it can become a reliable data source throughout the service life of a facility. Laser scanning technology is able to capture accurate geometric data in the form of a point cloud and to depict the existing condition of a building. Hence, point cloud data captured by laser scans can be used as references to update a given BIM. An important step during the update process is to match segments of elements captured by a point cloud to building components modeled in a BIM, so that the discrepancies between the two data sets can be identified. Typically, features depicted within point cloud segments and BIM components are used in the matching process. However, understanding is limited regarding which features enable the matching process and how these features perform....

An approach to combine progressively captured point clouds for BIM update

Building information models (BIMs) provide opportunities to serve as an information repository to store and deliver as-built information. Since a building is not always constructed exactly as the design information specifies, there will be discrepancies between a BIM created in the design phase (called as-designed BIM) and the as-built conditions. Point clouds captured by laser scans can be used as a reference to update an as-designed BIM into an as-built BIM (i.e., the BIM that captures the as-built information). Occlusions and construction progress prevent a laser scan performed at a single point in time to capture a complete view of building components. Progressively scanning a building during the construction phase and combining the progressively captured point cloud data together can provide the geometric information missing in the point cloud data captured previously. However, combining all point cloud data will result in large file sizes and might not always guarantee additional building component information. This paper provides the details of an approach developed to help engineers decide on which progressively captured point cloud data to combine in order to get more geometric information and eliminate large file sizes due to redundant point clouds.

Leveraging BIM to Provide Automated Support for Efficient Troubleshooting of HVAC-Related Problems

AbstractPrompt response and troubleshooting of HVAC-related problems in facilities are vital to ensure a comfortable indoor environment for occupants. Two main challenges in the current practice result in an ad hoc troubleshooting process and waste of resources: the lack of access to the required facility and system information in a timely manner and the large search space of possible causes for a given HVAC-related problem. This paper presents a formalized approach to bring solutions to these problems. The approach reasons with a facility-specific model-based information repository in order to identify an accurate set of applicable causes for a reported HVAC-related problem in the large search space of possible causes and to retrieve related facility and system information. By eliminating the inapplicable HVAC components and space-related factors for a reported problem, the approach increases the efficiency of the troubleshooting process. The research enhances the existing body of knowledge in the facili...

Automated approach for developing integrated model-based project histories to support estimation of activity production rates

AbstractCurrently, historical production information for an activity and the corresponding contextual information depicting the conditions under which a production rate is achieved are stored in multiple dispersed data sources, if they are stored. This results in extra time and effort spent in searching, gathering, and integrating information while estimating the activity production rates in new bids. Because estimators work on tight schedules to deliver bids, this may impede estimators from being able to use the neutral and objective data related to past performances. This paper describes a general algorithm developed for data storage, an approach that facilitates the storage of activity-specific production and contextual information in an integrated fashion within project models. This approach employs both an as-planned and an as-built project model as inputs, integrates these models by performing automated mappings between them, and augments this integrated model with activity-specific production and c...

Towards a Formal Approach for Determining Functions of HVAC Components Represented in IFC

The maintenance of Heating Ventilation and Air Conditioning (HVAC) systems is one of the fundamental activities in facilities management groups. HVAC systems are configured from basic types of components, such as dampers, fans, valves and coils, and there are usually multiple instances of the same type of components performing different functions in an HVAC system. For example, in relation to dampers, an HVAC system can contain an outside air damper, a discharge air damper, a return air damper, a mixed air damper, and multiple variable air volume dampers. It is also a similar case for other components such as valves, coils and fans. When HVAC mechanics perform maintenance activities, they usually need to check HVAC components with specific functions, and know information about such components, such as “where is the outside air damper?” The information related with different HVAC components can be represented and exchanged using Building Information Models (BIM). Among BIM data standards, IFC represents more information in relation to HVAC for Facilities Management (FM) purpose. However, the bottleneck of using IFC to provide information support for HVAC maintenance is that current IFC standard does not differentiate functions of HVAC components of the same type, and thus it is not possible to identify HVAC components with specific functions and retrieve their information from an IFC file directly. This study presents the need for an approach to deduce the functionalities of HVAC components from their existing topological information represented in IFC files. This approach, once formalized, can be used as a basis to automatically retrieve required information from IFC-based BIM for HVAC mechanics during maintenance tasks.

AN APPROACH FOR CAPTURING REQUIREMENTS OF COLLABORATIVE DESIGN TEAMS TO FACILITATE EVALUATION OF ENERGY EFFICIENT RETROFIT DESIGN OPTIONS

Four and a half million non-residential buildings in the U.S are estimated to be suitable candidates for energy retrofits (McGraw Hill, 2009). The current process of evaluating design alternatives for energy efficient retrofit projects uses drawings and 3D renderings together with documents to share energy simulation results and associated assumptions. Due to document-based information exchange, it is challenging for collaborative design teams to interpret energy implications of every design option, perform integrated analyses of design information with energy model results, and compare these energy implications with those of other design options. Immersive and interactive workspaces could improve the process by allowing teams to easily visualize assumptions and energy simulation results integrated with 3D models. Various parties are involved in collaborative design teams and each has a unique role, necessitating communication of task-specific assumptions and information requirements. Hence, there is a need to first identify what engineered information that collaborative teams should share in enabling design alternative evaluation and what visualization forms design teams would need. This paper presents an approach for capturing the information/visualization requirements of collaborative design teams as they implement and leverage immersive and interactive visualization settings. An iterative approach was taken within which virtual mockups were created using information requirements identified through brainstorming with energy modeling experts and then presented to collaborative design teams in order to acquire more information/visualization requirements. This research is part of a larger effort in the Energy Efficient Buildings (EEB) Hub at the Philadelphia Navy Yard, and uses Building 661, currently undergoing retrofit, as a case study. This paper presents the initial use case, information requirements identified, and virtual prototypes developed.

Design and Evaluation of an Integrated Visualization Platform to Support Corrective Maintenance of HVAC Problem-Related Work Orders

AbstractHVAC mechanics need to know various information items about a facility and its building systems to troubleshoot HVAC-related problems. Whether HVAC mechanics can comprehend the situation and pinpoint the problem source in an efficient way is affected by how the required information is provided to them. This research study builds on the hypothesis that the visualization of the required information for HVAC mechanics can improve the time efficiency of the decision making for the troubleshooting process, and there is research needed to understand how much time efficiency can be achieved by visualization. Hence, this study utilizes a user-centered and iterative process to design and implement a visualization platform to support troubleshooting of HVAC-related problems. The final visualization platform is evaluated through user studies with quantitative metrics. The findings show that using the developed platform HVAC mechanics could save more than 50% of the time to identify the cause for a reported H...

Deviation Analysis of the Design Intent and Implemented Controls of HVAC Systems Using Sensor Data: A Case Study

Sustainable building system design techniques aim to find an optimal balance between occupant comfort and the energy performance of HVAC systems. Design and implementation of effective heating ventilating and air conditioning (HVAC) controls is the key to achieve these optimal design conditions. Any anomalies in the functioning of a system component or a control system would result in occupant discomfort and/or energy wastage. While occupant discomfort can be directly sensed by occupants, measurement of waste in energy use would require additional sensing and analysis infrastructure. One way of identifying such a waste is to compare asdesigned system requirements with the actual performance of the systems. This paper presents an analysis of an air handling unit (AHU) in a five story office building and provides the comparison results of design requirements against the sensor data corresponding to the AHU parameters. One year sensor data for the AHU parameters was analyzed to assess the correctness of the implementation of the design intent. The design intent was interpreted from the sequence of operations (SOOs) and confirmed with a commissioning engineer, who worked on the project. The design intent was then graphically represented as a pattern that the sensor data corresponding to the controls is expected to follow if it follows the design intent. Any deviation in the sensor data as compared to the expected operation pattern of the design intent indicated incorrect operation of the system with incorrectly implemented controls. The findings in this paper substantiate the need to formally define the sequence of operations and also point to the need to verify the implemented controls in a given project to detect any deviations from the actual design intent.

Challenges Associated with Generating Accurate As-Is Building Information Models for Existing Buildings by Leveraging Heterogeneous Data Sources

Nowadays, facility management (FM) teams are facing challenges to generate accurate and semantically-rich as-is BIMs for existing buildings. Current model creation approaches, such as model generation based on point cloud data, mainly capture geometric information of a building and lack to provide additional semantic information about components and other project information. This paper provides the results of a detailed case study that aimed at leveraging existing data sources (e.g., archived documents and data in FM systems) to generate accurate and semanticallyrich as-is BIMs. The initial findings from the case study highlighted two main challenges associated with model generation from existing data sources: information extraction and integration. Existing information for different components is typically stored in heterogeneous data sources with various formats and quality, and hence requires different approaches to extract information. The findings also showed that almost 40% of the component attributes investigated had conflicting values in existing sources. In order to address these challenges, formalized approaches are required to support conflict resolution, data extraction and integration.

A framework to generate accurate and complete as-built bims based on progressive laser scans

It is a general expectancy that in most of the construction and renovation project, the contractor is going to hand over the as-built documents to the owner or the facility management team at the completion of the project. The main challenge for the handover process is to ensure the completeness of the captured building information and the accuracy of it in terms of how well it represents the reality. Building information models (BIMs) can be used as an information repository to store and deliver as-built information. However, due to changes made in the construction and renovation phases and errors made in the design and modeling phases, discrepancies can exist between BIMs created in the design phase (asdesigned BIMs) and actual building conditions. Laser scanning technology is able to efficiently capture accurate geometric information, which provides an opportunity to identify and quantify discrepancies and update as-designed BIMs into as-built BIMs. This paper presents a case study, within which the asdesigned BIM of a newly renovated research lab was updated into an as-built BIM using laser scanned data captured in the renovation phase. This paper introduces the challenges associated with the updating process for the as-designed BIM. In order to address these challenges, this paper introduces a framework that supports the update of an as-designed BIM by incorporating point clouds captured by the progressive laser scans.