Dynamically generated block diagrams as a visualisation method

Block diagrams are a popular tool for representing relationships in complex systems and became a kind of universal language, comprehended widely in engineering sciences dealing with dynamical systems. There are many software development environments (e.g. Simulink, LabVIEW, VisSIM) accepting such block diagrams as a programming language. However, block diagrams are rarely used in the field of systems visualisation dominated by custom made process flow diagrams. This paper presents a concept of using block diagrams as a tool for run-time presentation of a time-variant structure of complex control systems. At first, formal description of block diagrams is derived as an ontology, class hierarchy, and XML Schema. In the second part of the paper developed software tools are presented i.e. equation parser, Web Service implemented in a dynamic agent-based control system, and an AJAX-based application visualising acquired models as live interactive vector diagrams. Existing solutions for automated diagram spatial arrangement are not proper for block diagrams containing feedback loops, therefore presented visualisation tool, to achieve comprehendible and aesthetical layout, implements modified approach, which is thoroughly discussed.