Bond graph based sensitivity and uncertainty analysis modelling for micro-scale multiphysics robust engineering design

Components within micro-scale engineering systems are often at the limits of commercial miniaturization and this can cause unexpected behavior and variation in performance. As such, modelling and analysis of system robustness plays an important role in product development. Here schematic bond graphs are used as a front end in a sensitivity analysis based strategy for modelling robustness in multiphysics micro-scale engineering systems. As an example, the analysis is applied to a behind-the-ear (BTE) hearing aid. By using bond graphs to model power flow through components within different physical domains of the hearing aid, a set of differential equations to describe the system dynamics is collated. Based on these equations, sensitivity analysis calculations are used to approximately model the nature and the sources of output uncertainty during system operation. These calculations represent a robustness evaluation of the current hearing aid design and offer a means of identifying potential for improved designs of multiphysics systems by way of key parameter identification

Modeling Stiffness and Damping in Rotational Degrees of Freedom Using Multibond Graphs

A contribution is proposed for the modeling of mechanical systems using multibond graphs. When modeling a physical system, it may be needed to catch the dynamic behavior contribution of the joints between bodies of the system and therefore to characterize the stiffness and damping of the links between them. The visibility of where dissipative or capacitive elements need to be implemented to represent stiffness and damping in multibond graphs is not obvious and will be explained. A multibond graph architecture is then proposed to add stiffness and damping in hree rotational degrees of freedom. The resulting joint combines the spherical joint multibond graph relaxed causal constraints while physically representing three concatenated revolute joints. The mathematical foundations are presented, and then illustrated through the modeling and simulation of an inertial navigation system; in which stiffness and damping between the gimbals are taken into account. This method is particularly useful when modeling and simulating multibody systems using Newton-Euler formalism in multibond graphs. Future work will show how this method can be extended to more complex systems such as rotorcraft blades' connections with its rotor hub.Fondation Airbus Grou

Trends in modeling and simulation in the automotive industry concerning the bond graph framework

Modeling is a process by which an experiment (organized way of obtaining data) can be applied to answer questions about a system; taking into account that a system, in summary, is a potential source of data and a simulation is the experimentation of the possible behavior of a system in a model. Both (modeling and simulation) are processes to develop and test theories in many fields of application of engineering. This paper presents a study of trends in modeling and simulation concerning the Bond Graph reference framework, carried out through an analysis based on bibliometric maps. The results show a strong connection between simulation models and the automotive industry in the frame of reference Bond Graph

Modelling and simulation of a hydraulic power assisted steering system through Bond Graphs

The hydraulic power assisted steering (HPAS) system is one of the most sensitive vehicle interfaces to the driver perception. Comfort and performance parameters such as ride, handling, tactile transfer functions and overall noise levels are directly affected by its performance. The modeling of a HPAS system using the bond graph technique makes possible the combination of hydraulic and mechanical components. This allows physical and design variables such as fluid compressibility and hoses diameters to be evaluated simultaneously. HPAS should be used as a design and tuning tool to develop different system configurations before prototype test build, representing an improvement in terms of product development time and cost for both component and vehicle level