scholarly journals Discussion: “The Properties of Bond Graph Junction Structure Matrices” (Ort, J. R., and Martens, M. R., 1973, ASME J. Dyn. Syst., Meas., Control, 95, pp. 362–367)

1976 ◽  
Vol 98 (2) ◽  
pp. 209-209 ◽  
Author(s):  
Alan S. Perelson
Author(s):  
W Favre ◽  
S Scavarda

In this paper a bond graph representation of the point contact joint between two bodies with any outline curves and in planar motion is proposed. The body geometry and frames are described, the kinematic constraints attached to the point contact joint are identified and the bond graph junction structure is deduced. The example of an elliptic cam-follower is used to illustrate the bond graph representation. In particular this shows the need for the simulation to add strong damping and very stiff elements to the system.


Author(s):  
Wolfgang Borutzky

Analytical redundancy relations are fundamental in model-based fault detection and isolation. Their numerical evaluation yields a residual that may serve as a fault indicator. Considering switching linear time-invariant system models that use ideal switches, it is shown that analytical redundancy relations can be systematically deduced from a diagnostic bond graph with fixed causalities that hold for all modes of operation. Moreover, as to a faultless system, the presented bond graph–based approach enables to deduce a unique implicit state equation with coefficients that are functions of the discrete switch states. Devices or phenomena with fast state transitions, for example, electronic diodes and transistors, clutches, or hard mechanical stops are often represented by ideal switches which give rise to variable causalities. However, in the presented approach, fixed causalities are assigned only once to a diagnostic bond graph. That is, causal strokes at switch ports in the diagnostic bond graph reflect only the switch-state configuration in a specific system mode. The actual discrete switch states are implicitly taken into account by the discrete values of the switch moduli. The presented approach starts from a diagnostic bond graph with fixed causalities and from a partitioning of the bond graph junction structure and systematically deduces a set of equations that determines the wanted residuals. Elimination steps result in analytical redundancy relations in which the states of the storage elements and the outputs of the ideal switches are unknowns. For the later two unknowns, the approach produces an implicit differential algebraic equations system. For illustration of the general matrix-based approach, an electromechanical system and two small electronic circuits are considered. Their equations are directly derived from a diagnostic bond graph by following causal paths and are reformulated so that they conform with the matrix equations obtained by the formal approach based on a partitioning of the bond graph junction structure. For one of the three mode-switching examples, a fault scenario has been simulated.


1975 ◽  
Vol 97 (2) ◽  
pp. 189-195 ◽  
Author(s):  
A. S. Perelson

The relationship between the port constitutive equations of a bond graph junction structure and the constitutive equations of its individual junctions is investigated. By combining network, bond graph, and graph theoretic techniques, the roles of bond orientation and causal assignments in determining when internal bond variables may be eliminated are examined. Graphical criteria are proven for establishing when a junction structure is an n-port.


2012 ◽  
Vol 482-484 ◽  
pp. 1062-1067
Author(s):  
Zhong Shuang Wang ◽  
Jian Guo Cao ◽  
Ji Chen

For the kineto-static analysis of complex planar linkage, the procedure based on vector bond graph is proposed. The constraint force vectors at joints can be considered as unknown effort source vectors and added to the corresponding 0-junctions of the system vector bond graph model, most of the differential causalities in system vector bond graph model can be eliminated . In the case of mixed causality, the unified formulae of driving moment and constraint forces at joints are derived based on vector bond graph, which are easily derived on a computer in a complete form. As a result, the very difficult algebraic problem caused by differential causality and nonlinear junction structure can be overcome, and the automatic kineto-static analysis of complex planar linkage on a computer is realized. By a practical example, the validity of this procedure is illustrated.


2001 ◽  
Author(s):  
B. M. J. Maschke ◽  
A. J. van der Schaft

Abstract In this paper we propose a bond graph formulation of interdomain coupling extending the symplectic gyrator proposed in the so-called generalized or thermodynamic bond graph formalism. Therefore we use as power and energy variables exterior differentiable k-forms on the Euclidean space. The bonds and power variables are of two types: the first type represents the energy flows inside a domain Ω of the Euclidean space and the second type represent the energy flows through the boundary ∂Ω of the domain. It will be shown that the interdomain coupling may be represented as a 3-port power continuous element, called Stokes-Dirac Junction Structure, whose constitutive relation is defined using solely the exterior derivative of k-forms. This general result is applied to the examples of a transmission line, the electro-magnetic field and the vibrating string.


1975 ◽  
Vol 97 (4) ◽  
pp. 439-441 ◽  
Author(s):  
D. Karnopp

When bond graphs are generated from reasonable physical systems according to standard rules, there are only rare cases in which power loops arise that yield singular algebraic relations among effort and flow variables. On the other hand, if one assembles bond graphs from subsystem models, paradoxical situations may arise in which sign conventions and causality interact strangely and in which physically impossible situations seemingly occur. Some useful bond graph identities are shown which often eliminate such paradoxes. The general conclusion is that a bond graph containing a junction structure power loop should be carefully examined with respect to sign convention and to see whether a simplifying identity can be used before causality is applied and equations are formulated.


Author(s):  
Roger F Ngwompo ◽  
René Galindo

Integrated dynamic systems such as mechatronic or control systems generally contain passive elements and internal energy sources that are appropriately modulated to perform the desired dynamic actions. The overall passivity of such systems is a useful property that relates to the stability and the safety of the system, in the sense that the maximum net amount of energy that the system can impart to the environment is limited by its initial state. In this paper, conditions under which a physical system containing internal modulated sources is globally passive are investigated using bond graph modelling techniques. For the class of systems under consideration, bond graph models include power bonds and active (signals) bonds modulating embedded energy sources, so that the continuity of power (or energy conservation) in the junction structure is not satisfied. For the purpose of the analysis, a so-called bond graph pseudo-junction structure is proposed as an alternative representation for linear time-invariant (LTI) bond graph models with internal modulated sources. The pseudo-junction structure highlights the existence of a multiport coupled resistive field involving the modulation gains of the internal sources and the parameters of dissipative elements, therefore implicitly realizing the balance of internal energy generation and dissipation. Moreover, it can be regarded as consisting of an inner structure which satisfies the continuity of power, and an outer structure in which a power scaling is performed in relation with the dissipative field. The associated multiport coupled resistive field constitutive equations can then be used to determine the passivity property of the overall system. The paper focuses on systems interconnected in cascade (with no loading effect) or in closed-loop configurations which are common in control systems.


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