Bond Graph

Oil well drilling has always been one of the challenging subjects in engineering, and during the past decade in order to enhance the efficiency, this process has been developed in many aspects which cause more difficult problems in scientific fields. Besides, in many countries the oil reservoirs are located in ultra-depth and as a consequence this process is going to be more severe. Especially to attain more hydrocarbon products such as oil and gas, the deviated drilling technology is used. By using this type of drilling this subject needs more research and survey on its treatment. In this paper a directional oil well drill string is concerned and the related bond graph model is developed. It has a Bottom Hole Assembly (BHA) that will be mentioned in the paper. But this is just a sample case and it can be various in its BHA, depth and slope.

A mathematical model describing the dynamic characteristics of the vehicle needs to be solved for predicting the future position and orientation of vehicle relative to the changing environment. By reducing the time consumed to solve the complex model, the cycle time for the overall process can be decreased. The work done in this paper, attempts to reduce the computational time by mathematically finding the redundant elements, which do not add to the major dynamics of the system but increase the calculation time by increasing the system complexity. Here, in this paper, eigenvalue separation and eigenvalue sensitivity methods have been applied to the different bond graph models of bicycle vehicle with suspension system, antilock braking system, steering system and four wheel vehicle models. The reduced system behaviour is similar to the response from the actual bond graph model. This method is applicable to linear systems as well as for the non-linear systems after certain modifications.

ABSTRACT This paper presents a short comparison of different existing and proposed wave prediction models, which in turn are used to control wave energy converters (WEC) in irregular waves. The objective of the control action is to increase the energy conversion. The prediction models are compared based on the contribution to the prediction of the individual filter weights, in an effort to reduce the filter order. The controller is based on adjusting the short term stiffness and damping of the power take off (PTO) of the WEC. The control action, which is a fuzzy logic (FL) based design, is supported by utilizing nominal damping and stiffness values determined for the given sea state and instantaneous wave using a simple genetic algorithm (GA). The WEC chosen is comprised of a spherical buoy and is modeled using the bond-graph technique. The simulation carried out indicates the proposed algorithm increases the energy conversion of WEC in irregular waves compared to the no control case.

This work addresses the construction of a four- wheel, nonlinear vehicle dynamic bond graph model and its implementation in the 20sim modeling and simulation environment. Nonlinear effects arising from the coupling of vertical, longitudinal and lateral vehicle dynamics, as well as geometric nonlinearities coming from the suspension system are taken into account. Transmission and (a simplified) engine models are also

The premise of this thesis is to compare valve control and pump control methodologies for excavator boom lift applications. Equations of motion were derived from classical bond graph techniques and simulations were run via AMESIM modeling software. Bond graph models of the two systems were presented along with conclusions and recommendations.

This paper examines methods that can be adopted in early stage or retrot design of actuator subsystems, and is motivated by the modern trend toward retrotting legacy hydraulic actuation of submarine control surfaces with electromechanical systems. This problem highlights the familiar need designers have to relate system response requirements to selected subsystems to enable focused development of the latter. This paper shows the utility of adopting a model basis, and specically uses a bond graph approach in combination with two-port immittance relations. Bond graphs benet study of multidisciplinary systems and provide insight into system interconnection and causality. In combination with bond graphs, immittance functions enable key relations to be established based on the overall system description, and provide a way to specify response requirements. Immittance functions also enable adopting network synthesis methods, which are used in this paper to show how passive and active compensation can be integrated to benefit proposed actuation schemes. It is shown how this combination of methods provides designers with a systematic way of relating system response requirements to targeted subsystems. The methods described are demonstrated using a simplied control surface actuation problem, and simulation results of key static and dynamic requirements are presented. The derived passive and active compensation are used to augment conventional feedback controlled actuator models, and simulations demonstrate how compensation can reduce energy consumed by actuation subsystems.

The context of this PhD thesis is the modelling and design of mechatronic systems. The study is positioned in the early design stage of the conception cycle (V-Cycle), where the main efforts have to be produced in terms of methodology, to enhance the quality and the functionality of the products, and based on virtual prototyping (modelling and simulation). One of the possible methodology is to reformulate the design problem as an inverse problem, in order to directly use the design specification of the product, usually given in terms of the system outputs, and then solve the design problem. In this context, the Ampere laboratory of INSA Lyon has developed a conception and design methodology, based on inverse approach and using the bond graph formalism, to propose a step-by-step method based on dynamic and energetic criteria, with a structural analysis phase that allows hierarchical analysis steps, depending on the structural physical layout of the model (topological, phenomenological, parameter set). The aim of the present works is to contribute to the development of this methodology, by enhancing it to the class of descriptor systems. This choice is led by the aim to apply the methodology in the context of chassis design and vehicle dynamics, where, among other, multi-body models represented as a differential-algebraic equation (DAE) system could occur. The contributions are proposed at the level of the topology of the model, as well as at the level of the phenomenological / behavioral aspects. A preliminary step is to enhance the existing algebraic framework to support graphical extension (in term of digraph and bond graph). The overall methodological extensions allow, firstly, a generalization of the approach to the class of descriptor systems, and, secondly, to reach a standardization of the procedures, previously dedicated to direct or inverse models, so as no mandatory differences between those models have to be done anymore.

Los sistemas dinámicos pueden ser analizados de diferentes maneras, sin embargo no todos los métodos permiten su aplicación computacional.  El presente trabajo describe cómo resolver sistemas dinámicos aplicando el método bond graph, desarrollando las bases para su aplicación computacional en sistemas de potencia fluida (oleohidráulica).  Esta aplicación puede extenderse a diferentes sistemas dinámicos y representa una alternativa de análisis diferente a los métodos más tradicionales.

Offshore hydraulic cranes are difficult to operate safely, accurately and efficiently due to their heavy structure, large inertia, non-intuitive control interface and load sway issues that result from external disturbances. This paper presents an effective heave compensation and anti-sway control approach for offshore crane operations, which is based on robotic arm kinematics and energy dissipation principles. Unlike common operator-based joint-by-joint control procedures, this automated method is more flexible, allowing for more intuitive crane operations and more accurate positioning of the hoisted load. In particular, a unique feature of this approach is that the two control functions of heave compensation and anti-sway are transparently combined and simulated in an integrated modelling environment. The system architecture integrates the control model for crane operations, the hydraulic system model for hydraulics characteristic analysis, the 3D model of the crane to be controlled, the vessel and the environment for visualization. The proposed control algorithm and simulation model can be extended to any type of crane model regardless of its configuration or degree of freedom (DOF) without influencing the effectiveness of the method. The hydraulic model is built by using Bond Graph elements and integrated with the control model in the 20-sim simulation environment. The crane operation can be simulated and controlled by the operator using a 3-axis joystick, which provides a transparent user interface. Related simulations were carried out to validate the efficiency and flexibility of the system architecture. As a case study, a 3-joints knuckle boom crane was implemented and tested. The simulation results prove the presented control algorithm for heave compensation and anti-sway to be a valid and efficient solution.

Magnetic  Levitation  has  been  a  keen  area  of
research,  especially  in  the  field  of  automotive  where  low
losses  due  to  friction  and  low  energy  consumption  are
important  considerations.  This  paper  offers  the  theoretical
and  experimental  idea  of  the  magnetic  force  control  in  the
magnetic  levitation  system  using  the  bond  graph  modeling
approach considering the  nonlinearities. The corresponding
levitation  apparatus  comprises  of  an  electromagnet,  a
ferroelectric material base, a steel ball and position sensors.
The  force  generated  by  the  electromagnet  causes  the
levitation action over the ball by balancing the gravitational
force  exerted  on  the  ball.  The  present  work  describes  the
linear and nonlinear model using signal flow graph a nd bond
graph  approach.  Transfer  function  of  the  setup  is  obtained
using  signal  flow  graph  and  correspondingly  the  balancing
action of the ball at its levitating position is performed using
a  PID  controller.  Lastly  the  overall  system  stability  is
validated using root locus approach.

This paper presents a new way to derive an optimal control system for a specific optimisation problem, based on bond graph formalism. The procedure proposed concerns the optimal control of linear time invariant MIMO systems and can deal with both cases of the integral performance index, these correspond to dissipative energy minimization and output error minimization. An augmented bond graph model is obtained starting from the bond graph model of the system associated with the optimal control problem. This augmented bond graph, consisting of the original model representation coupled to an optimizing bond graph, supplies, by its bicausal exploitation, the set of differential-algebraic equations that analytically give the solution to the optimal control problem without the need to develop the analytical steps of Pontryagin’s method. The proof uses the Pontryagin Maximum Principle applied to the port-Hamiltonian formulation of the system.

This paper presents a Bond Graph (BG) modelling approach to add and exploit on existing Modelica models some information on the energy structure of the systems. The developed models in the ThermosysPro library (Modelica-based) are already validated against the experimental data in previous works. A plate heat exchanger (PHE), which is equipment for nuclear power plants, is considered as a case study in this paper. Simulation results of the BG model for the counterflow PHE are compared with simulation results of the tested Modelica model. Comparisons show good agreement between both model results.

For the benefit of engineers working outside the bicycle industry, this paper describes some engineering considerations related to the development of a new model full suspension bicycle fork. The impact of market forces on the development process is considered, and a description of various design tools currently in use is provided. A detailed model of a new fork travel adjustment feature is included, along with simulation results produced by this model. The paper also includes an overview of the laboratory testing resources that are used to ensure the robustness of contemporary bicycle components. © 2008 John Wiley and Sons Asia Pte Ltd

Abstract. This work deals with the development of a feedback controller for an active suspension system to be applied in a high performance elevator. The elevator has a double-deck cabin and will be used in a 200 [m] course guide in a skyscraper of almost 500 [m]. The elevator's ...

Physical systems are by nature continuous. Perceived discontinuities in system models are in reality nonlinear behaviors that are linearized to reduce computational complexity and prevent stiffness in system analysis and behavior generation. Discontinuities arise primarily from component parameter simplification and time-scale abstraction. Discontinuities in models are handled by introducing idealized switching elements controlled by finite state automata to bond graph models. In this paper, we make a systematic study of the nature ...

This paper presents modelling and simulation of multi-scroll chaotic attractors by using a new simple and more general bond graph model. For this purpose, the multi-segment non-linear resistor in Chua’s circuit is modelled by using piecewise linearization with control inequalities. The proposed model consists of active/passive circuit elements, voltage-controlled current source (VCCS) and ideal switches. The advantage of modelling multi-segment