A bond graph approach to analysis, synthesis, and design of dynamic systems.

摘要

The objective of this dissertation was the development of a design methodology for dynamic systems based on a bond graph formulation. In this study, the target systems are restricted to three groups: two-port linear reciprocal lumped passive systems, linear MIMO lumped systems with active elements, and systems containing distributed and lumped elements.; For the first case, the synthesis methodology based on immittance theory developed from classic circuit theory was developed. Immittance matrix and wave scattering matrix are used as design specifications. The method can be used to derive a bond graph for the system which will satisfy the desired frequency response. The parametric values of elements and the structural topology of the designed system is obtained from the bond graph and the method can be used to design a reliable prototype of a newly conceived system.; In the second case, a model-based synthesis methodology for active elements has been developed using an impedance-based approach. In this methodology, a hybrid optimization process combining a gradient method and a genetic algorithm is used for obtaining rational approximations of active elements considering stability of the system. To validate this proposed method it was applied to active suspension of a half-car model and active vibration suppression of a two-story building model. The results show that this method offers a viable tool for the retrofit of an existing system using active elements.; For the third case, a model-based redesign methodology for a dynamic system containing both distributed and lumped elements is developed. It has been found that an effective redesign procedure begins by determining the design specifications, formulating a bond graph model, analyzing sensitivity of each system element, and performing an optimization process. The validity of this methodology was demonstrated by redesigning two dynamic systems: a long shaft system with inertial and bearing load, and a performance test system containing complicated geometry of rotors (impellers), discontinuity dynamics, and open thermodynamic system phenomena.; Combining these three methodologies contributes to an integrated design methodology that can cover a broad range of design applications for dynamic systems.