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In this paper, the control of a solar array is proposed. The bond graph methodology is applied in order to get the structure control law for a solar array connected to the electrical network. For this, the different models of the complete system are presented. The solar array is built up by considering the individual solar panels. The inverter bond graph model is used for the development of the proposed control law. This model is inverted graphically to get the control structure. Also, the Park transformation concept is adapted to handle the control structure. This allows us to get a different control structure. Two different controls are considered in the proposed control structure, with their robustness tested for different power factors. The control law is tested using a real-time simulator. For this test, the rapid control prototyping concept is used. The obtained results demonstrate the viability of the proposed control law. [ABSTRACT FROM AUTHOR]

• An electromechanical hydraulic integrated agricultural tractor model by utilizing the bond graph model is developed. • The general power flow model of the electric tractor with mechanical shunt type is also derived. • Using MPGA leads to reduce state of charge (SOC) fluctuations and the remaining SOC is higher, the theoretical hydrogen fuel consumption is decreased. The fuel cell electric tractor has emerged as a new development direction in modern agriculture due to its energy-controllable and emission-reducing advantages. This paper focuses on improving the universality of basic research by studying the fuel cell electric tractor with mechanical shunt type (FCETMST). The bond graph model has the benefits of cross-physical system integration. To fill the gap in general modeling of electric tractors, an electromechanical hydraulic integrated machine model by utilizing the bond graph model, which includes energy system, drive system, lifting system and power take-off (PTO) system, is developed. The general power flow model of the electric tractor with mechanical shunt type is also derived. Lastly, the accuracy of the model is validated by analyzing the tractor's traction characteristics. To further enhance energy efficiency, this paper proposes an energy management strategy (EMS) utilizing a multi-population genetic algorithm (MPGA) and compares it with a power following control strategy (PFCS) for a fuel cell/lithium battery composite energy system. The results base on the co-simulation by using AVL-Cruise and Matlab/Simulink to build a vehicle simulation model and EMS models, respectively, show that under ploughing and transportation conditions, compared with the traditional PFCS, using MPGA leads to reduce state of charge (SOC) fluctuations and the remaining SOC is 11.22 % and 6.1 % higher, respectively. The theoretical hydrogen fuel consumption is decreased by about 26.49 % and 36.21 %, respectively. This study can provide theoretical support for the modeling and energy management optimization of the electric tractor system. [ABSTRACT FROM AUTHOR]

For a connected graph G , with deg G ( v i ) and ɛ G ( v i ) denoting the degree and eccentricity of the vertex v i , the non-self-centrality number and the total irregularity of G are defined as N ( G ) = ∑ | ɛ G ( v j ) − ɛ G ( v i ) | and i r r t ( G ) = ∑ | deg G ( v j ) − deg G ( v i ) | , with summations embracing all pairs of vertices. In this paper, we focus on relations between these two structural invariants. It is proved that irr t ( G ) >  N ( G ) holds for almost all graphs. Some graphs are constructed for which N ( G ) = i r r t ( G ) . Moreover, we prove that N ( T ) >  irr t ( T ) for any tree T of order n  ≥ 15 with diameter d  ≥ 2 n /3 and maximum degree 3. [ABSTRACT FROM AUTHOR]

Abstract Fault detection and isolation (FDI) is an essential task that allows avoiding the fault consequence on the performance of the system. The bond graph, as a modelling tool, provides through its structural and causal properties, an automatic generation of analytical redundancy relations (ARRs). These relations are used for diagnosis applications, they constitute the mathematical constraints that are used to verify the coherence between the process measurements and the reference of the system behaviour represented by the model. The classical ARR diagnosis approach allows to both detect and isolate the defective component in the system. In this work, the main goal is to increase the number of isolable faults by increasing the number of ARRs, using the output of the bond graph model along with the measured output of the real system. The innovative interest in this work is that the number of the isolated faults can be improved without the addition of more sensors. Following the general discussion of the proposed method, a robotic subsystem (traction of an omnidirectional mobile robot) is considered to validate the proposed procedure. Two faulty scenarios are then presented and discussed using both the classical and the proposed approach.The proposed method is able to isolate 3 faults that can not be isolated using classical ARR. [ABSTRACT FROM AUTHOR]

Heat exchanger networks are important systems in most thermal engineering systems and are found in applications ranging from power plants and the process industry to domestic heating. Achieving cost-effective design of heat exchanger networks relies heavily on mathematical modelling and simulation-based design. Today, stationary design calculations are carried out for all new designs, but for some special applications, the transient response of complete networks has been researched. However, simulating large heat exchanger networks poses challenges due to computational speed and stiff initial value problems when flow equations are cast in differential algebraic form. In this article, a systems approach to heat exchanger and heat exchanger network modelling is suggested. The modelling approach aims at reducing the cost of system model development by producing modular and interchangeable models. The approach also aims at improving the capability for large and complex network simulation by suggesting an explicit formulation of the network flow problem. [ABSTRACT FROM AUTHOR]

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This paper proposes a new method for fault detection and isolation of a large-scale system by the bond graph (BG) model and the principal component analysis (PCA) technique in a decentralized architecture. The proposed method is entitled the BG-PCA technique. The main objective is to address the problem of monitoring large-scale system components by fault detection and isolation (FDI) methods. In the modeling framework, the BG model is presented by exploiting its structural and causal properties and the diagnostic bond graph (DBG). In measurement noise and perturbation conditions, the probability density function takes place to generate a clear decision procedure to detect the operating mode. In our approach, we firstly generate the structured residues. Furthermore, with a decentralized architecture, we can locate in what subsystem a fault is first detected. Finally, for isolation, the generation of the structured residues method from PCA is exploited to ensure localization. To validate the suggested BG-PCA algorithm, simulations are computed on a three-tank system to show the efficiency of the proposed FDI method, and satisfactory results are found. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Chemical engineering process is modeled using bond graph approach. • Interactions of different thermal and hydraulic phenomena are considered. • Energetic parameters are determinate by simulation study. • Experimental results are confronted to simulation results. • Analytical redundancy relations are developed for diagnosis and isolation of default. Abstract This paper deals with the modeling of a chemical engineering system, which is the double effect evaporator (DEE). The main physical phenomenon encountered in this system is the heat transfer during distillation and concentration process. The modeling of DEE is carried out using bond graph approach. It allows description of interdisciplinary systems involving energetic, thermodynamic, hydraulic and thermal phenomena. In this study a dynamical models for the different parts of the DEE system are established. Simulation data are presented and confronted to the experimental results. To supervise the DEE system, the bond graph model is used to obtain analytical redundancy relations (ARR). They allow detection and isolation of faults. [ABSTRACT FROM AUTHOR]

Highlights • A hydraulic power transmission from off-shore wind turbine to generator is proposed. • A multi-energy bond graph model of the turbine and hydraulic system is developed. • Priority flow divider valve and accumulator are used in the power hydraulic system. • The hydraulic transmission stabilizes output speed when the wind speed fluctuates. Abstract This work proposes a novel approach to obtain a nearly constant power output from an offshore wind turbine by incorporating a priority flow divider valve and an accumulator into the power hydraulic system. The priority flow divider valve allows flow in two different ways, i.e. priority line and by-pass line, simultaneously. It controls the fluid (seawater) flow by adjusting its priority port flow as per the user setting to ensure minimum fluctuation of power output, whereas the excess flow is passed through the by-pass port and stored in an accumulator. A control strategy is applied on the control valve to allow the flow from the accumulator to the nozzle as per demand. A mathematical model of wind turbine with hydraulic power transmission is developed by using bond graph technique, which is suitable for this multi-energy domain system. Simulation results show that the output from the wind turbine is stabilized by using the proposed hydraulic power transmission system under fluctuating wind speed. [ABSTRACT FROM AUTHOR]

Thrombectomy by aspiration is one of the most effective systems for vessel recanalization. We present the results of a study on the modelling and elimination of blood clots in the arteries of the human body using Bond-Graph methodology. The modelling focuses on the clot and the distal end section of an aspiration device that improves the effectiveness of the treatment by reducing the risk of breaking the clot. The final model considers an elastic characterization of the blood clot and the possibility of achieving a process of progressive detachment of the clot from the vessel wall. An optimization process based on a design of experiments (DOE) is undertaken. The results show good agreement between the Bond-Graph techniques and the Finite Element Method models considered for validation (Computer Fluid Dynamics and nonlinear mechanics). Physical tests with gelatine also validate the results. We conclude that the proposed geometry will potentially improve the results of recanalization when blood clots are extracted from the arteries for a range of given parameters. [ABSTRACT FROM AUTHOR]

A systematic method for constructing models in the complementarity framework from a bond graph is proposed. Bond graphs with and without storage elements in derivative causality are considered. The proposed method allows the study of switching systems represented by a bond graph model of fixed causality. The proposed methodology allows the complementarity framework to be exploited in different engineering areas by using bond graphs.The idea of representing a unidirectional switch with a model that is essentially the same as a diode is presented. By employing a similar representation for diodes and switches, the modeling and simulation of power switching converters are simplified and become more intuitive. Two application examples are shown. A non-inverting buck-boost converter and a zeta converter with an element in derivative causality are simulated. [ABSTRACT FROM AUTHOR]

In this paper, a bond graph model of a mobile robot with four Mecanum wheels is developed to extract a dynamic model of the robot. This is achieved using the BG_V21 tool box of MATLAB. The dynamic model thus obtained is used to derive the control law for trajectory tracking by the robot. There are two control algorithms that are used, namely, the flatness-based controller and the backstepping controller. From the simulation results, it is evident that the extracted dynamic model of the robot is accurate. Moreover, the flatness-based controller proved to have the upper hand in performance over the backstepping controller. [ABSTRACT FROM AUTHOR]

Nowadays, there is a combine effect of piezoelectric material performances and energy harvesting management strategy increase. As the same time, the energy consumption of electrical components and circuits decrease. Thus, this leads to a growing interest in recovering low energy level with piezoelectric cantilever beam in the suspensions of an automotive vehicle to perform predictive maintaining operations for example. For this purpose, a Bond Graph model of suspension with an embedded piezoelectric beam has been proposed since it gives the keys to find an optimal configuration for the energy harvester. The Bond Graph language is well adapted to translate multiphysics exchange of energy and power from mechanical to electrical conversion. In order to validate simulation results, a prototype of piezoelectric energy harvester has been built and tested in a laboratory environment. Furthermore, this study has been supplemented by measurements performed on a road and simulations are in good keeping with these proposed experimental tests. In view of an energy balance, small power but with a long duration harvesting has been obtained. Therefore, energy harvester may be interesting for a punctual use with a large period of electrical loading. [ABSTRACT FROM AUTHOR]

In this paper, the problem of robust Fault Detection (FD) for continuous time switched system is tackled using a hybrid approach by combination of a switching observer and Bond Graph (BG) method. The main criteria of an FD system including the fault sensitivity and disturbance attenuation level in the presence of parametric uncertainties are considered in the proposed FD system. In the first stage, an optimal switching observer based on state space representation of the BG model is designed in which simultaneous fault sensitivity and disturbance attenuation level are satisfied using H_/H1 index. In the second stage, the Global Analytical Redundancy Relations (GARRs) of the switching system are derived based on the output estimation error of the observer, which is called Error-based Global Analytical Redundancy Relations (EGARRs). The parametric uncertainties are included in the EGARRs, which define the adaptive thresholds on the residuals. A constant term due to the effect of disturbance is also considered in the thresholds. In fact, a two-stage FD system is proposed wherein some criteria may be considered in each stage. The efficiency of the proposed method is shown for a two-tank system. [ABSTRACT FROM AUTHOR]

Let G be a graph of order n . The energy E ( G ) of a simple graph G is the sum of absolute values of the eigenvalues of its adjacency matrix. The Laplacian energy, the signless Laplacian energy and the distance energy of graph G are denoted by L E ( G ) , S L E ( G ) and D E ( G ) , respectively. In this paper we introduce a distance Laplacian energy D L E and distance signless Laplacian energy D S L E of a connected graph. We present Nordhaus–Gaddum type bounds on Laplacian energy L E ( G ) and signless Laplacian energy S L E ( G ) in terms of order n of graph G and characterize graphs for which these bounds are best possible. The complete graph and the star give the smallest distance signless Laplacian energy D S L E among all the graphs and trees of order n , respectively. We give lower bounds on distance Laplacian energy D L E in terms of n for graphs and trees, and characterize the extremal graphs. Also we obtain some relations between D E , D S L E and D L E of graph G . Moreover, we give several open problems in this paper. [ABSTRACT FROM AUTHOR]

Application of model-based estimation techniques to kick detection come with constraints imposed on the structure of the mathematical model by stochastic estimation algorithms as well as the limited number of flow-line measurements typically available in most drilling operations. This, along with high computational cost of numerical models call for low to medium order deterministic models that still capture the dominant effects of fluid flow during drilling. A built-for-purpose single phase deterministic model for conventional drilling is presented. The model development is the first step in a two-step process of real-time early kick detection using stochastic estimation techniques. The model is developed using lumped parameter modeling afforded by bond graph modeling technique. Aside a hydraulic model for the wellbore, well-formation interactions that give rise to kicks, lost circulation, and wellbore breathing are also modeled and coupled. This holistic modeling approach provides a compact set of low order equations which makes stochastic estimation feasible, and well monitoring easier so that, for example, wellbore breathing is not mistaken for kicks, leading to unnecessary non-productive time and possibly inducing kicks due to needless well control actions undertaken. Lumped well parameters are calibrated with an optimization tool, and the model is validated using historical data from a conventionally drilled, onshore well. [ABSTRACT FROM AUTHOR]

The increasing demand for vibration reduction in several high-tech industries has motivated many researchers to investigate novel vibration isolation techniques. Understanding the vibration transfer paths within a system is an essential part of designing an effective vibration isolation strategy. In this paper, an analytical transfer path analysis algorithm is proposed suitable for multi-energy-domain systems. The bond graph modeling technique, which is an effective approach to model multi-energy-domain systems, is used to extend the concept of transmissibility to such systems. In this paper, an electro-hydro-mechanical system is used as a benchmark example to elucidate the effectiveness of the proposed technique. An energy based path ranking algorithm based on the bond graph model of the system is also conducted. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to use bond graphs to retain system structures, linking dynamic models and the transfer functions of control systems, and develop a universal analysis method for eliminating the right-half-plane zeros (RHP-zeros) of systems. Although previous literature has investigated RHP-zero elimination, their findings were only applicable to specific systems. When such a system is modified, only a trial-and-error method can be applied to eliminate the RHP-zeros of systems. The main feature of the proposed method involves the analysis of the causal paths contained in bond graphs. Analysis results then serve as a guideline for RHP-zero elimination, which can involve processes including modification of model structures or changes to paths. This method improves the system to get a better performance, instead of using the trial-and-error methods. Finally, a boost converter with an RHP-zero is applied to various examples of RHP-zero elimination, verifying that the proposed methodology can be used to eliminate the RHP-zeros of systems without the need of a trial-and-error process. [ABSTRACT FROM PUBLISHER]

Mathematical models of cardiac action potentials have become increasingly important in the study of heart disease and pharmacology, but concerns linger over their robustness during long periods of simulation, in particular due to issues such as model drift and non-unique steady states. Previous studies have linked these to violation of conservation laws, but only explored those issues with respect to charge conservation in specific models. Here, we propose a general and systematic method of identifying conservation laws hidden in models of cardiac electrophysiology by using bond graphs, and develop a bond graph model of the cardiac action potential to study long-term behaviour. Bond graphs provide an explicit energy-based framework for modelling physical systems, which makes them well suited for examining conservation within electrophysiological models. We find that the charge conservation laws derived in previous studies are examples of the more general concept of a 'conserved moiety'. Conserved moieties explain model drift and non-unique steady states, generalizing the results from previous studies. The bond graph approach provides a rigorous method to check for drift and non-unique steady states in a wide range of cardiac action potential models, and can be extended to examine behaviours of other excitable systems. [ABSTRACT FROM AUTHOR]

The n-dimensional hypercube Qn is bipancyclic and contains a 3-regular, 3-connected subgraph on l vertices for every even l from 8 to 2n except 10. In this paper, we strengthen the previous works to Cartesian product of paths. The bipancyclicity and the existence of 3-regular subgraphs of Cartesian product of paths are studied in this paper. [ABSTRACT FROM AUTHOR]

Industrial systems have become quite complicated. It is therefore necessary to look for a reliable supervision system to properly treat the information and make the appropriate decision to stop the system or leave it in operation. Supervision of automated systems goes to the heart of the matter. This paper concerns the design of a new methodology for diagnosis based on bond graph modeling. We apply a diagnostic method by Luenberger observer using the bond graph approach on a desalination unit. Tests are carried out on the water input pressure delivered by the pump and the output ow rates of the reverse osmosis. This method will allow us to test normal and failure operations of an industrial system. The roles of diagnostic systems for industrial processes consist of detecting and locating faults, also called residues, that will affect these processes. In order to be effective, the diagnostic system should be robust for residue analysis and insensitive to false alarms. In this context, the development of the proposed method is described from the step of modeling to the step of generation of certain residues. [ABSTRACT FROM AUTHOR]

In this paper, a new methodology is proposed to determinate the controllability and the observability matrices of linear time varying systems modeled by bond graph. As the bond graph model can be viewed as a state space representation and as a module (algebraic approach), the determination of controllability and observability matrices is presented with the graphical approach. The equivalence between the two approaches (Graphic, Mathematical) is proposed and a graphical methodology is pointed out directly on the bond graph representation. [ABSTRACT FROM AUTHOR]

A central theorem in combinatorics is Sperner's Theorem, which determines the maximum size of a family F ⊆ P ( n ) that does not contain a 2-chain F 1 ⊊ F 2 . Erdős later extended this result and determined the largest family not containing a k -chain F 1 ⊊ … ⊊ F k . Erdős and Katona and later Kleitman asked how many such chains must appear in families whose size is larger than the corresponding extremal result. This question was resolved for 2-chains by Kleitman in 1966, who showed that amongst families of size M in P ( n ) , the number of 2-chains is minimized by a family whose sets are taken as close to the middle layer as possible. He also conjectured that the same conclusion should hold for all k , not just 2. The best result on this question is due to Das, Gan and Sudakov who showed that Kleitman's conjecture holds for families whose size is at most the size of the k + 1 middle layers of P ( n ) , provided k ≤ n − 6 . Our main result is that for every fixed k and ε > 0 , if n is sufficiently large then Kleitman's conjecture holds for families of size at most ( 1 − ε ) 2 n , thereby establishing Kleitman's conjecture asymptotically. Our proof is based on ideas of Kleitman and Das, Gan and Sudakov. Several open problems are also given. [ABSTRACT FROM AUTHOR]

Energy-based modeling is often very appropriate for physical system modeling for development and analysis of multi domain dynamic system models. One such tool for modelling of system is bond graph (BG), which allows to model complex system, with clear interconnection rules and preserving the physical structure of the system. In various engineering system, operation is carried out on various time scale. One such area of generic system is microgrid, where multidisciplinary microgrid components operating on various time scales. In such hybrid system, flows and efforts comprise a very good choice of variables to link components for system stability and performance analysis. Since components are typically connected through various power electronics devices, mathematical modeling capable of capturing high frequency behavior is of utmost concern in stability analysis. Solid state transformer (SST) is one such device playing a key role in bi-directional power flow between the grid and various renewable sources. This paper proposes the use of the BG approach to recognize the energy representation of the microgrid in port-Hamiltonian form by looking at the energy transformation aspects of microgrid components. The port-controlled Hamiltonian systems (PCHS) are the mathematical description of bond graphs which allows integration of subsystems of hybrid microgrid using energy as the linking concept. To illustrate the utility of BG in hybrid systems, basic PI controller is implemented. The aim of the paper is to show how to model complex systems in bond graph domain. [ABSTRACT FROM AUTHOR]

A new model for simulating photovoltaic (PV) systems is presented. Bond Graph modelling is used as a basis technique. The proposed model allows prediction of generated energy under nonstandard conditions of temperature and irradiance. The proposed model is based on a 4-parameters model of the equivalent circuit of one diode. The proposed model has the property of being able to simulate the behaviour of a given PV module based only on information provided in the manufacturer datasheet. The proposed model also allows studying the effect of partial shading. As an advantage over other existing models of PV systems, the proposed model presents an extensive interconnection capacity. This feature allows simultaneous simulation with other subsystems to study the overall operation. For purposes of experimental validation of the proposed model, the construction of a tracer based on MOSFET that acts as a variable load is performed. The hardware control and reading of the curves are made using a data acquisition board. [ABSTRACT FROM AUTHOR]

This paper presents a solution for the state and unknown input estimator of linear MIMO systems with a structural approach based on Bond Graph methodology. A systematic procedure is initially proposed at the analysis stage by studying the finite and infinite structures of the modeled system from a structural approach, similar to the case study for the classical input-output decoupling problem and the disturbance rejection problem. Afterwards, the observer that can be represented by a Bond Graph model is directly implemented from the original model at the synthesis stage. The monovariable case as well as the multivariable case are treated and the stability property of the classical error equations (state and disturbance) of the observer is studied, based on the stability property of the invariant zeros of the model. The observer is tested by an illustrative example that considers a real bar system used for different cases. [ABSTRACT FROM AUTHOR]

The physical system design is more complex day after day due to the advancement in technology. In this paper, bond graph modelling of a multi domain physical system like skid steered mobile is presented. The proposed method is used to describe the dynamics of the system in various physical domains. By applying the bond and junction properties, mathematical model is extracted. In the second part of the paper, an unified technique is proposed to control the robot along the predefined complex trajectory. To track the desired trajectory, a flatness-based controller is proposed for the mobile robot. The developed dynamic model and the controller is modelled using BG V20 toolbox in MATLAB. Open loop as well as closed loop simulation are carried out to check the efficacy of the proposed model. Experimental trials performed in simulation environment revealed that the developed dynamic model and the controller for the robot can efficiently track the desired trajectory. [ABSTRACT FROM AUTHOR]

A model library for the turbocharged diesel engines using the pseudo-bond graph based on the three-level structure, technical component level, physical concept level and mathematical level, is presented. For each level, a general framework is explained. The detailed pseudo-bond graph models of each part of the engine as well as the mathematical models are presented. After that, a specific model for the 16PA6V-280STC turbocharged diesel engine is presented. Steady-state conditions of the model are validated with the experiment data. Dynamic conditions, such as the instantaneous load increase, rotational speed transient from 730 rpm to 1000 rpm, are simulated and validated. The evolutions of engine speed, load, rack position, of the dynamic processes are presented. Finally, the influence of the compression ratio and fuel supply advance angle on the specific fuel consumption of the diesel engine is studied on the 20-sim-Matlab co-simulation platform. [ABSTRACT FROM AUTHOR]

The ability of Bond Graph (BG) in modeling multi-domain structures results in a more precise and expansive interface. Hence, this paper develops the model of a quadrotor using BG approach. Then, the paper introduces and optimizes a Fuzzy Logic Controller (FLC) with the aim of making intelligent decisions close to human decisions. Additionally, a Particle Swarm Optimization (PSO) algorithm is utilized to have minimum 4 rules for FLC, which leads the controller to be quick. It is because a fast FLC is necessary in the next part to convert the controller to a full one (considering all main states). Furthermore, two Proportional-Integral-Derivative (PID) controllers have helped the FLC to bring all the main states of quadrotor under control. In addition, the set points for the angles, which cause higher nonlinearity behavior, could now be set close to π/2. Furthermore, multi-domain model of the system has helped in modeling of constant and random variable wind disturbances for which a logical solution is suggested. [ABSTRACT FROM AUTHOR]

A bond graph model-based prognosis method for multiple components with unknown degradation patterns in a hybrid dynamical system is proposed. The traditional approach for remaining useful life prediction with single degradation model is inappropriate for hybrid systems where the dynamics changes according to operating mode. Therefore, multiple degradation models are suggested and these are adapted with new information of the degradation states of the monitored system. Sensitivity-based dynamic signature matrix is utilized for degradation hypothesis generation which provides the deviation directions of fewer hypothesized degradation parameters and thereby accelerates parameter and degradation trend estimation. The results are supported by experiments. [ABSTRACT FROM AUTHOR]

Designing robust circuits that withstand environmental perturbation and device degradation is critical for many applications. Traditional robust circuit design is mainly done by tuning parameters to improve system robustness. However, the topological structure of a system may set a limit on the robustness achievable through parameter tuning. This paper proposes a new evolutionary algorithm for robust design that exploits the open-ended topological search capability of genetic programming (GP) coupled with bond graph modeling. We applied our GP-based robust design (GPRD) algorithm to evolve robust lowpass and highpass analog filters. Compared with a traditional robust design approach based on a state-of-the-art real-parameter genetic algorithm (GA), our GPRD algorithm with a fitness criterion rewarding robustness, with respect to parameter perturbations, can evolve more robust filters than what was achieved through parameter tuning alone. We also find that inappropriate GA tuning may mislead the search process and that multiple-simulation and perturbed fitness evaluation methods for evolving robustness have complementary behaviors with no absolute advantage of one over the other. [ABSTRACT FROM AUTHOR]

Quadruped robots provide better stability and speed in comparison to other legged robots. However, its joint actuator or sensor failure severely affects locomotion. Strategies for actuator and sensor fault accommodation in a compliant legged quadruped are presented here. A pair of orthogonally mounted moving appendages mechanism is proposed here to accommodate locked joint failure. These appendages as rack mounted inertias perform controlled motion during actuator failure. A strategy for sensor fault accommodation is also presented. A three-dimensional multi-body dynamics model of quadruped robot and its fault accommodation strategies are developed using bond graph modeling approach. The control performance is validated both through simulations and experiments. [ABSTRACT FROM AUTHOR]

A hybrid machine tool is a complex mechatronic system and the complex interactions between the mechanical subsystem and the control subsystem have an important effect on the dynamic performance of the machine tool. In this paper, mechatronics modeling and forced vibration of a 2-DOF parallel manipulator in a 5-DOF hybrid machine tool are investigated. The mechatronics model is derived by using bond graph and the elastic deformation of the link with the lowest stiffness is considered in modeling. An approach to investigate the interactions between the mechanical subsystem and the control subsystem is proposed in frequency domain, by using the close-loop frequency response (CFR) of control loops and the frequency response function(FRF) of the moving platform. Based on the interactions between the mechanical subsystem and the control subsystem, the forced vibrations induced by motion command input and cutting forces are investigated, respectively. The results show that higher bandwidth and lower structural frequency lead to more interactions between the mechanical subsystem and the control subsystem. This paper explores bond graph techniques as a modeling tool, which can help engineers in the process of creating mechatronics system from scratch. [ABSTRACT FROM AUTHOR]

A particular class of nonlinear singularly perturbed systems by using a bond graph approach is proposed. The class of nonlinear systems is defined by terms of product of state variables whose bond graph representation is described by MTF or MGY elements modulated by state variables. The singular pertubations applied to the system permit the separation of time scales. When the assumptions of Tikhonov Theorem are satisfied, then a new bond graph called singularly perturbed nonlinear bond graph (SPNBG) to determine the quasi-steady-state model of the system is presented. The SPNBG is characterized by having an integral causality assignment for the storage elements that represent the slow dynamics, and the storage elements of the fast dynamics have a derivative causality assignment. Finally, the proposed methodology is applied to an illustrative example. [ABSTRACT FROM AUTHOR]

This paper proposes a generic tool named Hybrid Bond Graph (HBG) driven by an automaton. Along with the conventional Bond Graph (BG) properties, the proposed approach offers some very valuable advantages in modelling the Hybrid Dynamical Systems (HDS). It allows having one global model of all the distinct dynamics called dynamical operating modes generated due to the hybrid aspect of the system. Compared with other classical approaches such as the hybrid automata, the Operating Mode Management (OMM) is much simpler and more effective thanks to the separation between the continuous dynamics associated with the BG continuous state and the discrete state governed by a separate classical automaton. From the diagnosis point of view, the approach allows to obtain one global graphical robust diagnoser simply derived from the model using the Linear Fractional Transformation (LFT). Using the BG causal properties along with the correspondences between the system components and the BG elements, the Event-Driven Hybrid Bond Graph (EDHBG) also helps to associate between the faults and their suspected components. The innovative interest in this work is that it allows for a non-expert user to perform the modelling, the on-line robust diagnosis and the OMM, without expressing the algebraic equations of the system and regardless of its hybrid aspect. A pedagogic experimental set-up serving as a comprehensive example is implemented on 20Sim 1 to demonstrate the potential of this technique. [ABSTRACT FROM AUTHOR]

This paper deals with the modeling of bond graph buck converter systems. The bond graph formalism, which represents a heterogeneous formalism for physical modeling, is used to design a sub-model of a power MOSFET and PiN diode switchers. These bond graph models are based on the device's electrical elements. The application of these models to a bond graph buck converter permit us to obtain an invariant causal structure when the switch devices change state. This paper shows the usefulness of the bond graph device's modeling to simulate an implicit bond graph buck converter. [ABSTRACT FROM AUTHOR]

This paper describes a novel formalism for modelling uncertain system parameters and measurements, as interval models in a Bond Graph (BG) modelling framework. The main scientific interest remains in integrating the benefits of BG modelling technique and properties of Interval Analysis (IA), for efficient diagnosis of uncertain systems. Structural properties of Bond graphs in Linear Fractional transformation (BG-LFT) are exploited to model interval-valued uncertainties over a BG model in order to form an uncertain BG. The inherent causal properties are exploited to generate interval-valued fault indicators. Then, various properties of IA are used to generate point valued residual and interval-valued thresholds. The latter must contain the point valued residuals under nominal system functioning. A systematic procedure is proposed for passive-type fault detection method which is robust to uncertain system parameters and measurements. The viability of the method is shown through experimental study of a steam generator system. The limitations associated with existing fault detection method based on BG-LFT are alleviated by the proposed approach. Moreover, it is shown that proposed approach generalizes the BG-LFT method. This work forms the initial step towards integrating interval analysis based capabilities in BG framework for fault detection and health monitoring of uncertain systems. [ABSTRACT FROM AUTHOR]

Closed-loop control systems are designed for linear time-invariant (LTI) controllable and observable systems modelled by bond graph (BG). Cascade and feedback interconnections of BG models are realised through active bonds with no loading effect. The use of active bonds may lead to non-conservation of energy and the overall system is modelled by proposed pseudo-junction structures. These structures are build by adding parasitic elements to the BG models and the overall system may become singularly perturbed. The structures for these interconnections can be seen as consisting of inner structures that satisfy energy conservation properties and outer structures including multiport-coupled dissipative fields. These fields highlight energy properties like passivity that are useful for control design. In both interconnections, junction structures and dissipative fields for the controllers are proposed, and passivity is guaranteed for the closed-loop systems assuring robust stability. The cascade interconnection is applied to the structural representation of closed-loop transfer functions, when a stabilising controller is applied to a given nominal plant. Applications are given when the plant and the controller are described by state-space realisations. The feedback interconnection is used getting necessary and sufficient stability conditions based on the closed-loop characteristic polynomial, solving a pole-placement problem and achieving zero-stationary state error. [ABSTRACT FROM PUBLISHER]

In this work, a multi-domain model of the stator core of an electric machine is presented. Its electromagnetic behavior and the thermal dynamics are represented using Bond Graph. This approach makes apparent the topology of the machine and the energy exchange. This feature enables the model for the easy representation of faults and analysis of their consequences in the thermal/magnetic/electric domain. The proposed model is used for reproducing the behavior of the stator core during an inter-laminar insulation test. The model is capable to reproduce the thermal distribution when a fault in the stator core occurs. This contribution helps to estimate the additional iron losses due to the stator core fault based on the thermal distribution. Additionally, this methodology could help to define the proper maintenance intervention to be performed on the machine. [ABSTRACT FROM AUTHOR]

An integrated vehicle-biodynamic model is developed in this article by using multi-domain energy domain bond graph model simulation and multi-body simulation software ADAMS VI-Rail. These models are specifically used to evaluate passenger ride comfort in a railway vehicle where vertical and lateral excitations at the wheels arise out of the track irregularities. In the bond graph model, the carbody of the railway vehicle is treated as an Euler-Bernoulli beam and its first five modes are included in the model. Thereafter, a detailed model of the railway vehicle is created in ADAMS VI-Rail. The International Organization for Standardization (ISO) 2631 specification is used to determine the passenger comfort for different travel durations and track irregularities. [ABSTRACT FROM AUTHOR]

In 2014, faculty and students at colleges around theworld participated in the Mega-Menger project to build a model of the Menger sponge, a type of fractal, out of business cards. This model can itself be modeled using graph theory, with each vertex representing a small cube and an edge between two vertices whenever they share a face. We determine the order, size, and partite set sizes of graphs representing different steps of building the Menger sponge and Sierpinski carpet, along with the surface area of the Menger sponge. Many results involve recurrence relations, which we work through in some detail. [ABSTRACT FROM AUTHOR]

In this paper an unified and integrated approach combining behavioral and functional aspects of the process to ensure an efficient online supervision in industrial field is proposed. Linear Fractional Transformation Bond Graph (BG-LFT) methodology is used to provide an on line robust Fault Detection and Isolation (FDI). This methodology is based on the behavioral and causal properties of the model to monitor specified components of the processes. Functional operating modes management is used to offer a decision making tool for online reconfiguration. The developed strategy is illustrated through an industrial steam generator application representing a part of a cardboard factory. [ABSTRACT FROM AUTHOR]

This work introduces a mathematical model for photovoltaic module based on manufacturing datasheet, ambient temperature and solar irradiation. This mathematical model of photovoltaic module is applied to its single diode equivalent electrical circuit using bond graph methodology. The developed model allows identifying the PV module's five parameters without going through an iterative process. In this work all the parameters of the photovoltaic module are given as a function of both ambient temperature and recorded solar irradiation. To prove the accuracy of the proposed model comparisons are done at standard test conditions as well as at random climate conditions using experimental data. Obtained results show that the proposed bond graph based identification method is very effective when fast computation of PV model parameters is needed. [ABSTRACT FROM AUTHOR]