Filters

Settings

Now showing1 - 2 of 2
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    An embedded algorithm for detecting and accommodating synchronization problems in wireless structural health monitoring systems
    (2017)
    Dragos, Kosmas
    ;
    Smarsly, Kay
    In wireless structural health monitoring systems, the inherent processing power of wireless sensor nodes enables the execution of structural health monitoring tasks in a decentralized manner. Decentralization may result in non-synchronized sets of structural response data, for example due to non-simultaneous triggering of the sensor nodes. Lack of synchronization is detrimental to the output of operational modal analysis (ΟΜΑ), which is frequently applied in SHM, leading to erroneous structural mode shapes. From a computer science perspective, synchronization approaches in wireless SHM systems center around clock synchronization schemes. In this paper, an embedded algorithm is presented that enables wireless sensor nodes to detect and to accommodate synchronization problems. The proposed algorithm draws from the theory of OMA and the expected relationship between the phase angles of frequency components corresponding to mode shapes obtained from different sets of structural response data. The embedded algorithm is implemented into a wireless SHM system and validated through laboratory tests on a shear frame structure.
    Publicationtype: Conference Paper
      36
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    IFC-based modeling of cyber-physical systems in civil engineering
    (2017)
    Smarsly, Kay
    ;
    Theiler, Michael
    ;
    Dragos, Kosmas
    The term "cyber-physical system" (CPS) refers to a new generation of engineering systems integrating computing, networking, and physical processes. Traditional building information, such as geometry, material or cost, can be represented based on the Industry Foundation Classes (IFC), an open standard used for building information modeling (BIM). However, information representing cyber-physical systems cannot be fully described with the IFC standard. Focusing on CPS applications in structural health monitoring and control, this paper presents an extension of the current IFC schema, enabling BIM-based modeling of cyber-physical systems in compliance with the IFC standard. BIM-based, IFC-compliant CPS modeling facilitates the design process, the documentation, and the information exchange of cyber-physical systems. In this study, a semantic model is developed, serving as a technology-independent metamodel to formally describe cyber-physical systems deployed in structural health monitoring and control applications. Supporting BIM-based, IFC-compliant modeling of cyber-physical systems, the semantic model is mapped into the IFC schema. Validating the BIM-based CPS modeling approach proposed herein, a CPS prototype for structural health monitoring and control is designed, implemented, and tested in laboratory experiments.
    Publicationtype: Conference Paper
      59