Bond Graph Modelling Based On Multi-Port And Model Reduction In Engineering

With the development of science and technology, the demand of a system is rising. Asystem designed on the condition of static or reliable state could not satisfy the scheduledrequirement. In order to obtain a system with good performance,dynamamic anlysis anddesign is needed. The engineering system,especially with high performance, is alwaysintegrated as a whole, electro-mechanical, hydro-mechanical or electro-hydro-mechanical. The dynamamic Performance of this system could not obtained by solutions inone domain. Aiming at this problem, the desseration carried out the research on bond graphmodelling based on multi-port and model reduction in engineering.The first part summarizes the status quo of multi-domain modelling and simulation,multi-domain united modelling methods and languages, graph-based multi-domain modelling,and bond graph modelling. Then discusses the existent problems. The significance ofobject-oriented bond graph modelling complex multi-domain system are put forward.The second part introduces the basic theory of bond graph modelling in outline, includingthe signal definition of bond graph basic elements and their physical characteristic andmathematical description in different engineering systems, causual relation of bond graph,basic method and process of deduce state equations from bond graph model.The third part researches in depth of object-oriented characteristic of bond graph, theexpression of bond graph elements and models in Modelica. Based on this, carried out theresearch of ideas and methods of component-based modelling, and promote acomponent-based modelling process.Part four introduces the physical model reduction method MORA algorithm, thenpromotes physical interpretation for different reduction situation. Based on this, this chapterimproves the MORA algorithm and promotes the concept of local activity based on junctionstructure, explains in detail the process of model transform, reduction, decomposition basedon local activity of junction structure.Part five builds a bond graph model for non-linear hydro-mechanical systems of a loaderand simulates it. The last part summarizes the research results of this paper, and gives the way for furtherresearch.