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Podder, Ankur

Publications and source records attributed to Podder, Ankur.

Automated Assembly Progress Monitoring in Modular Construction Factories Using Computer Vision-Based Instance Segmentation

Modular construction has recently gained interest as a transformative construction method. In this method, a large portion of the construction is performed inside factories, where processes are fast-paced and interdependent; therefore, any deviation from the schedule can delay the production. Such deviations are frequent in modular factories due to the labor-intensive nature of the tasks. This propagation of delays can be mitigated by continuously monitoring each process; however, current manual monitoring methods are laborious, and recently proposed contact sensor-based methods are intrusive to the work. In addition, recent computer vision-based monitoring methods inside factories are limited to detection algorithms that fail to provide the pixel-level accuracy required for assembly progress monitoring in highly occluded factory scenes, and they require a large number of manual annotations. Therefore, this paper proposes a method to monitor the installation of subassemblies in modular construction factories using mask R-CNN instance segmentation and improves the data efficiency of the model using a copy-paste augmentation method. This method was validated on the CCTV videos captured from a modular construction factory in the US, resulting in a 9% mAP improvement in segmentation.

computer vision↗

A New State of the Art: Zero Energy Modular Multifamily Construction

In 2020, the U.S. Department of Energy's Building Technologies Office (BTO) launched the Advanced Building Construction (ABC) Initiative. This initiative aimed to integrate energy efficiency into high-production construction practices. One focus area of the initiative is off-site construction, an approach that may achieve scalable, efficient, and high-performing construction buildings through process standardization. This report presents the findings and recommendations from our ABC Initiative project: A New State of the Art: Zero-Energy Modular Multifamily Construction System. The objectives of the BTO-funded project are to: 1) Achieve energy performance 50% better than the 2018 International Energy Conservation Code (IECC). 2) Achieve this level of energy performance at no additional cost VEIC worked with Louisiana State University (LSU), National Renewal Energy Lab (NREL), [the project team], and industry partners at the Mod Coach, KBS, and Solar Home Factory to identify and analyze multifamily business designs and modular construction practices. These designs and processes hold the promise of achieving the goals set out by the DOE.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Advanced Building Construction (ABC) Research Opportunities Report: Industrializing Construction to Decarbonize Buildings

The DOE Building Technologies Office generally seeks to develop, demonstrate, and accelerate the adoption of cost-effective technologies, techniques, and tools in support of an equitable transition to a decarbonized building stock and energy system by 2050. This ABC Innovations Roadmap specifically focuses on and prioritizes innovations that support the industrialization of whole building retrofits and rapid growth of efficient new construction. The content relates to the integration of technologies and industrialization of processes associated with building construction and renovation. The ABC Innovations Roadmap cross-applies innovations in both the new and existing building sectors with a focus on widescale applicability. Installation flexibility is key to commoditizing solutions that are applicable for a wide variety of buildings (e.g., different building types, vintages, architectural details, and system configurations) and to help simplify decarbonization processes for the workforce.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Advanced Building Construction (ABC) Research Opportunities Report: Industrializing Construction to Decarbonize Buildings

The U.S. building stock is responsible for 75% of total U.S. electricity use, 40% of energy use, and 35% of CO 2 emissions. To meet bold national climate change goals, the U.S. must decarbonize the building stock by 2050. However, today’s practices to build or renovate buildings to low-carbon, high-performance levels are generally labor intensive, disruptive, and too costly to quickly scale in the U.S. To retrofit 80% of the U.S. building stock in the U.S. by 2050, the retrofit rate will need to increase by about 15 times for residential buildings and two times for commercial buildings. Additionally, there is a major housing deficit in this country where nearly 600,000 people lack adequate or stable shelter, and the pace of construction is not keeping up with the growing demand. New, more industrialized, replicable, and technologically driven approaches to renovation and new building construction are imperative to help meet such significant national needs and achieve the necessary speed and scale to meet national building decarbonization goals.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Bottleneck Detection in Modular Construction Factories Using Computer Vision

The construction industry is increasingly adopting off-site and modular construction methods due to the advantages offered in terms of safety, quality, and productivity for construction projects. Despite the advantages promised by this method of construction, modular construction factories still rely on manually-intensive work, which can lead to highly variable cycle times. As a result, these factories experience bottlenecks in production that can reduce productivity and cause delays to modular integrated construction projects. To remedy this effect, computer vision-based methods have been proposed to monitor the progress of work in modular construction factories. However, these methods fail to account for changes in the appearance of the modular units during production, they are difficult to adapt to other stations and factories, and they require a significant amount of annotation effort. Due to these drawbacks, this paper proposes a computer vision-based progress monitoring method that is easy to adapt to different stations and factories and relies only on two image annotations per station. In doing so, the Scale-invariant feature transform (SIFT) method is used to identify the presence of modular units at workstations, and the Mask R-CNN deep learning-based method is used to identify active workstations. This information was synthesized using a near real-time data-driven bottleneck identification method suited for assembly lines in modular construction factories. This framework was successfully validated using 420 h of surveillance videos of a production line in a modular construction factory in the U.S., providing 96% accuracy in identifying the occupancy of the workstations and an F-1 Score of 89% in identifying the state of each station on the production line. The extracted active and inactive durations were successfully used via a data-driven bottleneck detection method to detect bottleneck stations inside a modular construction factory. The implementation of this method in factories can lead to continuous and comprehensive monitoring of the production line and prevent delays by timely identification of bottlenecks.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗