Positionspapier des Arbeitskreis Bauinformatik

Die Bauinformatik ist eine Säule der modernen Bau- und Umweltingenieurwissenschaften und befasst sich mit der Erforschung grundlegender informatorischer Methoden sowie mit der Anwendung und Weiterentwicklung der Informationswissenschaften im Bau- und Umweltbereich. Der Arbeitskreis Bauinformatik konstituiert sich aus Wissenschaftlern, die an Universitäten im deutschsprachigen Raum auf dem Fachgebiet Bauinformatik lehren und forschen. Ausgehend vom erreichten Entwicklungsstand der Bauinformatik skizziert dieses Positionspapier die Aufgaben des Arbeitskreises und formuliert eine Grundlage für eine abgestimmte Weiterentwicklung an den deutschsprachigen Universitäten

Indoor localization for augmented reality devices using BIM, point clouds, and template matching

Mobile devices are a common target for augmented reality applications, especially for showing contextual information in buildings or construction sites. A prerequisite of contextual information display is the localization of objects and the device in the real world. In this paper, we present our approach to the problem of mobile indoor localization with a given building model. The approach does not use external sensors or input. Accurate external sensors such as stationary cameras may be expensive and difficult to set up and maintain. Relying on already existing external sources may also prove to be difficult, as especially inside buildings, Internet connections can be unreliable and GPS signals can be inaccurate. Therefore, we try to find a localization solution for augmented reality devices that can accurately localize itself only with data from internal sensors and preexisting information about the building. If a building has an accurate model of its geometry, we can use modern spatial mapping techniques and point-cloud matching to find a mapping between local device coordinates and global model coordinates. We use normal analysis and 2D template matching on an inverse distance map to determine this mapping. The proposed algorithm is designed to have a high speed and efficiency, as mobile devices are constrained by hardware limitations. We show an implementation of the algorithm on the Microsoft HoloLens, test the localization accuracy, and offer use cases for the technology

Systematic literature review on smart contracts in the construction industry

The development of digital transformation in the construction industry has led to the increasing adoption of smart contracts. As programmable applications to automatically write, verify, and enforce transaction conditions, smart contracts can be used in different areas mainly to improve automation level, information security, and built digital environment enhancement. However, the smart contract is commonly mentioned as a blockchain appendage, while its unique connotation and value in the construction industry have not been recognized. Therefore, this study carries out a systematic review based on 81 research articles published from 2014 to 2021 on smart contract applications in construction to explore and highlight their potentials under domain-specific requirements. Results are analyzed according to research type categorization and domain codification. Eight research domains are identified, where the three most highly explored domains are contract and payment, supply chain and logistics, and information management. The integration of smart contracts with other innovative concepts and advanced technologies is analyzed. The applicability, benefits, and challenges of smart contract applications regarding different research domains are discussed

An empirical study on the acceptance of 4D BIM in EPC projects in China

The engineering-procurement-construction (EPC) method has the potential to help construction projects achieve sustainable performance, e.g., the contractor’s early involvement, cost savings, and a reduced schedule. However, high uncertainties and complexities are contained in EPC projects. 4D BIM (Building Information Modeling) with abilities to simplify the time and space relationships of construction activities and support multi-party information sharing is beneficial to EPC project management. The behavior pattern of the project personnel toward accepting 4D BIM information systems or tools needs to be explored. Therefore, a research model of the acceptance of 4D BIM in EPC projects with eight latent constructs is proposed through a literature review of technology acceptance theories. Data is collected from a questionnaire survey and interviews. Research hypotheses are examined using PLS-SEM (partial least squares-structural equation modeling). Empirical evidence is collected from China, and implications to the developing countries facing the challenge of developing a technology-intensive construction industry are provided: (1) Adopting 4D BIM in the EPC project is beneficial; (2) the task-technology fit plays a leading role in technology acceptance; (3) the management incentive is inefficient at the operational stage. Suggestions for future research on 4D BIM acceptance in complex construction projects with abundant data and alternative models are provided

A framework for automated acquisition and processing of As-built data with autonomous unmanned aerial vehicles

Planning and scheduling in construction heavily depend on current information about the state of construction processes. However, the acquisition process for visual data requires human personnel to take photographs of construction objects. We propose using unmanned aerial vehicle (UAVs) for automated creation of images and point cloud data of particular construction objects. The method extracts locations of objects that require inspection from Four Dimensional Building Information Modelling (4D-BIM). With this information at hand viable flight missions around the known structures of the construction site are computed. During flight, the UAV uses stereo cameras to detect and avoid any obstacles that are not known to the model, for example moving humans or machinery. The combination of pre-computed waypoint missions and reactive avoidance ensures deterministic routing from takeoff to landing and operational safety for humans and machines. During flight, an additional software component compares the captured point cloud data with the model data, enabling automatic per-object completion checking or reconstruction. The prototype is developed in the Robot Operating System (ROS) and evaluated in Software-In-The-Loop (SITL) simulations for the sake of being executable on real UAVs

Digital twin framework for enabling serial construction

Modularized construction with precast concrete elements has many advantages, such as shorter construction times, higher quality, flexibility, and lower costs. These advantages are mainly due to its potential for prefabrication and series production. However, the production processes are still craftsmanship, and automation rarely occurs. Fundamental to the automation of production is digitization. In recent years, the manufacturing industry made significant progress through the intelligent networking of components, machines, and processes in the introduction of Industry 4.0. A key concept of Industry 4.0 is the digital twin, which represents both components and machines, thus creating a dynamic network in which the participants can communicate with each other. So far, BIM and digital twins in construction have focused mainly on the structure as a whole and do not consider feedback loops from production at the component level. This paper proposes a framework for a digital twin for the industrialized production of precast concrete elements in series production based on the asset administration shell (AAS) from the context of Industry 4.0. For this purpose, relevant production processes are identified, and their information requirements are derived. Data models and corresponding AAS for precast concrete parts will be created for the identified processes. The functionalities of the presented digital twin are demonstrated using the use case of quality control for a precast concrete wall element. The result shows how data can be exchanged with the digital twin and used for decision-making

Using synthetic data to improve and evaluate the tracking performance of construction workers on site

Vision-based tracking systems enable the optimization of the productivity and safety management on construction sites by monitoring the workers’ movements. However, training and evaluation of such a system requires a vast amount of data. Sufficient datasets rarely exist for this purpose. We investigate the use of synthetic data to overcome this issue. Using 3D computer graphics software, we model virtual construction site scenarios. These are rendered for the use as a synthetic dataset which augments a self-recorded real world dataset. Our approach is verified by means of a tracking system. For this, we train a YOLOv3 detector identifying pedestrian workers. Kalman filtering is applied to the detections to track them over consecutive video frames. First, the detector’s performance is examined when using synthetic data of various environmental conditions for training. Second, we compare the evaluation results of our tracking system on real world and synthetic scenarios. With an increase of about 7.5 percentage points in mean average precision, our findings show that a synthetic extension is beneficial for otherwise small datasets. The similarity of synthetic and real world results allow for the conclusion that 3D scenes are an alternative to evaluate vision-based tracking systems on hazardous scenes without exposing workers to risks

Toolchains for interoperable BIM workflows in a web-based integration platform

The construction industry is characterized by the diversity of its processes, whereby persons involved in changing project communities are confronted with a changing interplay of software applications. Therefore, planning workflows, and especially the exchange of information between stakeholders, need to be formalized. The automation and execution of these workflows go one step further to achieve added value in implementation and project management using building information modeling. For the configuration and execution of collaborative BIM workflows with compatible software products, a framework is conceived and developed that enables the modeling of project-specific workflows by linking individual software tools based on a standardized process notation. The resulting toolchains enable seamless information exchange between applications that integrate an openCDE-compliant web interface. The methodological approach in this paper is a concept implementation, including a proof of concept. For the concept development, a review of the state of the art is conducted, and requirements are analyzed. The concept development comprises data models and API descriptions and includes the concept of a central integration platform. The interaction between workflow management on the platform and the execution of tasks in the software product clients is explained. The implementation of the toolchains on the proposed platform is evaluated in a demonstrator scenario

Automated payment and contract management in the construction industry by integrating building information modeling and blockchain-based smart contracts

Construction projects usually involve signing various contracts with specific billing procedures. In practice, dealing with complex contract structures causes significant problems, especially with regard to timely payment and guaranteed cash flow. Furthermore, a lack of transparency leads to a loss of trust. As a result, late or non-payment is a common problem in the construction industry. This paper presents the concept of implementing smart contracts for automated, transparent, and traceable payment processing for construction projects. Automated billing is achieved by combining Building Information Modeling (BIM) approaches with blockchain-based smart contracts. Thereby, parts of traditional construction contracts are transferred to a smart contract. The smart contract is set up using digital BIM-based tender documents and contains all of the relevant data for financial transactions. Once the contracted construction work has been accepted by the client, payments can be made automatically via authorized financial institutions. This paper describes the framework, referred to as BIMcontracts, the container-based data exchange, and the digital contract management workflow. It discusses the industry-specific requirements for blockchain and data storage and explains which technical and software architectural decisions were made. A case study is used to demonstrate the current implementation of the concept