Systematic bond graph

Systematic Bond Graph Generation for Mechanical Systems... 

Systematic Bond Graph Model Generation for Electrical Systems... 

Finally, with regard to condition based maintenance (CBM) of engineering systems it is important to detect the initiation of incipient faults, to assess the current health of a system and to predict the remaining useful life (RUL) of a component that has become faulty. As bond graph modelling enables the systematic generation of ARRs for FDI, it can also support failure prognosis. 

An incremental bond graph can be constructed in a systematic manner from the original bond graph of a switched LTI system by replacing an element that is due to parameter variations by its incremental element model. Equations for variations of power variables can be automatically derived in the same way as they are derived from an initial bond graph with nominal parameters. 

Section 5.3.1 has shown that parameter sensitivities of ARR residuals may be obtained from an incremental bond graph. The latter bond graph can be systematically developed from an initial bond graph with nominal parameters by replacing elements with parameters to be estimated by their incremental component model. Inputs into the incBG are variations of the parameters to be estimated multiplied by a power variable of the initial BG. Outputs may be parameter variations of ARR residuals. They are a weighted sum of the parameter variations and the weighting factors are just the residual sensitivity functions. 

The systematic manual derivation of equations from a causal bond graph shall be illustrated by considering the simple circuit depicted in Fig. B.6. 

Furthermore, studying the effect of component parameter uncertainties on the residuals of ARRs helps in fault isolation. Therefore, Section 4.6 addresses the systematic derivation of parameter sensitivities of residuals of ARRs from an incremental bond graph. 

The incremental bond graph is systematically constmcted by replacing elements with varying parameters by their incremental model. This step could be implemented in software. 

The objective here is to guide the reader to a systematic modehng process and an automated simulation process so that using the bond graph method one can generate a model so close to the physics of the system and let the computer take over the tasks of generating a computable model. Automation process for generation of the simulation model is a primary objective. The steps to take on this approach are as follows ... 

Let us look at the same mechanical example with the focus on this systematic approach to generate a bond graph with an automatic generation of a simulation model. 

What follows is the recommended systematic procedure for modeling electrical systems starting with the physical system and generating the bond graph. Let s try a circuit as those shown in [2],... 

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