Systematic Camera Placement Framework for Operation-Level Visual Monitoring on Construction Jobsites

Abstract

This paper proposes a camera placement framework that incorporates characteristics of complex construction jobsites. The proposed framework consists of three main processes: (1) identification of visual monitoring determinants, influencing factors, and camera placement conditions; (2) problem definition and mathematical modeling; and (3) hybrid simulation-optimization of camera placement on construction jobsites. To evaluate the performance of the proposed framework, a case study for an actual construction jobsite was performed. The results of the case study show the potential of the proposed framework to find the optimal number, types, locations, and orientations of cameras for jobsite visual monitoring. This research makes three main contributions: (1) identification of critical elements to be considered when installing fixed cameras on complex construction jobsites; (2) development of a systematic framework for camera placement on jobsites; and (3) visualization and quantification of multiple camera network designs and their performance (i.e., total costs and visible coverages) before installing cameras at actual jobsites.

Visual Analytics for Operation-Level Construction Monitoring and Documentation: State-of-the-Art Technologies, Research Challenges, and Future Directions

“…These keywords enabled to collect a sufficient number of academic papers regarding operation-level construction monitoring and documentation. It is worth mentioning that, however, other terms related to project-level monitoring [e.g., drone, unmanned aerial vehicle (UAV)] (Kim et al, 2019d) were not included because this review focused on operation-level monitoring. The articles were retrieved from each search engine using the keywords, and the results were integrated through the removal of duplicate ones that have same digital object identifier.…”

“…It can be defined as a problem that determines the proper number, types, locations, and orientations of cameras required to sufficiently monitor a large-scale jobsite. According to one recent study (Kim et al, 2019d), project managers generally carry out the camera placement based on their knowledge or experiences rather than systematic guidelines. Their decisions occasionally come with the acceptable performance of vision-based monitoring (in terms of camera coverage or total costs), but they often experience difficulty in determining appropriate camera configurations and recording video-streams owing to the complex and dynamic natures of a given jobsite (e.g., power supply, data transmissibility, occlusion effects).…”

“…One of the most urgent issues is that the dynamic and complex natures of construction and built environments has not been fully considered. Although one study incorporated various practical constraints of construction sites, such as power accessibility and data transmissibility (Kim et al, 2019d), most optimization techniques are based on an underlying assumption: construction sites are static, which means that jobsite components (e.g., structures, management offices, work zones) do not vary over time. Thus, existing camera networks for given jobsites are frequently unable to obtain appropriate video data (e.g., objects-of-interest are invisible from cameras), and further, they may need to be relocated as construction operations proceed, resulting in additional costs and monitoring difficulty.…”

“…Next, since earlier works developed camera placement methods for limited monitoring purposes and project types, it is still burdensome to determine a generalized camera placement framework and optimal configurations. In this regard, the approach proposed in the previous research (Kim et al, 2019d) can become a baseline for deriving and structuralizing diverse characteristics of construction sites. They categorized the characteristics of building construction sites into visual monitoring determinants, influencing factors, and camera placement conditions (i.e., camera network and jobsite conditions) based on the result of in-depth interviews with 12 construction experts.…”

“…Operation-level vision-based monitoring and documentation is vital to construction project managers because it enables to obtain useful information required for project management and control (Yang et al, 2015). By observing long-sequence video-streams collected by fixed cameras, managers can identify different types of activities performed by construction workers and equipment, and can measure their operational efficiency (e.g., direct work rate, hourly work amount) (Kim et al, 2018d(Kim et al, , 2019d. For instance, if too many workers are waiting to commence concreting operations, managers can decide to allocate more concreting equipment (e.g., pump cars, mixer trucks) or reduce the number of onsite workers.…”