Hybrid simulation of qualitative bond graph model

Qualitative simulation with traditional quantity space of physical systems is often inaccurate and ambiguous, while quantitative simulation is often subjected to the difficulty in establishing a precise mathematical model. Shortcomings of both simulations motivate the development of a hybrid qualitative and quantitative approach to do simulation of dynamic systems that presents the strengths of both. Qualitative representation of bond graph model is adopted to model a dynamic system. System measurements are represented by real numbers rather than qualitative values to improve accuracy. The integration of qualitative and quantitative information enhances the accuracy and effectiveness of qualitative simulation, and at the same time reduces the need for a precise mathematical model. The effectiveness of the proposed hybrid simulation approach is demonstrated by simulation studies of both linear and non-linear systems and experiments on the servo-tank liquid process rig. Key-Words: Bond graph, Dynamic system, Hybrid simulation, Qualitative reasoning