Object-oriented Modeling Environment Research Articles

Modeling the Movements of Mobile Robots Designed for Locomotion over the Undeveloped Terrains

Objectives: The relevance of the study is determined by the demand for all-terrain transport vehicles for investigating various celestial bodies. In this regard, the article considers the issues of modeling all-terrain transportation robot locomotion, for example, lunar rovers and Mars rovers over complex topography and sandy soils. Method: Methodological approaches for solving this problem emerged in the last century in connection with the creation of self-propelled chassis of Soviet lunar rovers and Mars rover mockups in the USSR. Modern software allows getting more informative simulation results directly in the process of computer-aided design of new machines. Findings: The article presents the development of the model of interaction between the wheel and the supporting plane in the object-oriented modeling environment whose results coincide with the experimental and operational test data of planetary rovers. In particular, it is possible to visualize the motion of all-wheel drive transportation robot models with combined wheel-walking propulsor. Walking mechanisms of such a propulsor are also used to perform adaptive suspension functions when moving in the wheel locomotion mode. Improvements: Materials of the article are of practical value for experts designing mobile robots, planetary rovers and other wheeled vehicles who use the simulation results to develop design and control systems. Keywords: Locomotion System, Mathematical Model, Mobile Robot, Object-Oriented Modeling, Planetary Rover, WheelWalking Drive

Modeling a healthy and a person with heart failure conditions using the object-oriented modeling environment Dymola.

Several mathematical models of different physiological systems are spread through literature. They serve as tools which improve the understanding of (patho-) physiological processes, may help to meet clinical decisions and can even enhance medical therapies. These models are typically implemented in a signal-flow-oriented simulation environment and focus on the behavior of one specific subsystem. Neglecting other physiological subsystems and using a technical description of the physiology hinders the exchange with and acceptance of clinicians. By contrast, this paper presents a new model implemented in a physical, object-oriented modeling environment which includes the cardiovascular, respiratory and thermoregulatory system. Simulation results for a healthy subject at rest and at the onset of exercise are given, showing the validity of the model. Finally, simulation results showing the interaction of the cardiovascular system with a ventricular assist device in case of heart failure are presented showing the flexibility and mightiness of the model and the simulation environment. Thus, we present a new model including three important physiological systems and one medical device implemented in an innovative simulation environment.

Dynamic modeling of an integrated air-to-air heat pump using Modelica

Heat pump systems have gained significant market shares in Europe recently. The control strategy is an asset for the efficient operation of these thermodynamic systems; especially with compact integrated components. The predictive control, which allows fast system stabilization, is based on the description of the system physical behavior. Thus, dynamic modeling is needed for the development of such control. The model has to represent the system response to usual external perturbations met during current operation such as the variation of air temperature and air mass flow rate. The aim of this paper is to present a dynamic model of a thermodynamic system developed in the Dymola environment, which is an object-oriented modeling environment. The heat-pump components are created separately as individual objects, and then connected to form the system. The model of each component is described and the responses to different perturbations are detailed. Simulation results are compared to test results in order to validate the model.

Підхід до створення об'єктно-орієнтованого середовища моделювання виробничих систем

An approach to the development of production system analysis&synthesis tools is proposed. The approach is based on an open object-oriented modeling environment extensible via specialized modules for solving a variety of problems. An XML-based interface for information exchange in the scope of the proposed modeling environment is introduced.

Modeling Water Quality Management Alternatives for a Nutrient Impaired Stream Using System Dynamics Simulation

A system dynamics (SD) simulation model is developed using an object-oriented modeling environment to simulate and analyze water quality management strategies for a nutrient impaired stream. An object-oriented simulation environment, STELLA, conceived on the principles of system dynamics (SD) is used for the development of the model. The modeling process consists of developing stock-flow diagrams and carrying out computer simulations using difference equations to integrate stocks and flows. The model structure and behavior of the system is validated using dimensionality, replication and sensitivity tests; and calibration along with validation is carried out using an appropriate model performance measure. The model helps the user to separate policy questions from the data and provides the facility to generate "what-if" scenarios while keeping the modeling process transparent. Case study application of this model is illustrated by developing a total maximum daily load (TMDL) allocation strategy for a nutrient impaired stream in the southeastern region of Kentucky, USA. Results suggest that the fate and transport process of total phosphorus in a river system can be simulated using a conceptually simple object-oriented simulation model.

Symbolic manipulation techniques for model simplification in object-oriented modelling of large scale continuous systems

In the present work, techniques for the symbolic manipulation of general nonlinear differential algebraic equation (DAE) systems are presented, and used for model simplification purposes, to support efficient simulation of large scale continuous systems in an object-oriented modelling environment. The specific problems addressed are efficient elimination of trivial equations by means of substitution, system block lower triangular (BLT) partitioning, and tearing, i.e. hiding of algebraic variables. Moreover, the weakening heuristic criterion for decoupling of large systems, via dynamic approximation, is studied. All these techniques have been successfully implemented and tested in MOSES (modular object-oriented software environment for simulation), in order to define a complete model simplification process. The results achieved by applying the discussed algorithms and criteria on serial multibody systems are illustrated. A brief overview on further known symbolic manipulation techniques is also given, comparing them with the proposed ones, throughout the paper.

A formal structure for discrete event simulation. Part II: Object-oriented software implementation for manufacturing systems

This paper describes the development of a prototype object-oriented software system for discrete event simulation and the embedded decision processes of a system being modeled based on previously defined formalism [1] and the Smalltalk programming language. The paper addresses the modular and structured representations of physical and logical entities of a manufacturing system for simulation modeling in the form of reusable software objects. The software takes advantage of the natural link between object-oriented programming and simulation and utilizes inheritance and other features of object-oriented programming to achieve modular yet uniform representation at every level of the model. After giving a brief overview of the object-oriented modeling environment and the relationships between software objects and formalism constructs, a small number of object classes and their operations are summarized. The intelligent entities of the formalism utilize a knowledge-based non-programmed decision mechanism implemented in Smalltalk.

ROLE OF SIMULATION IN RAPID PROTOTYPING FOR CONCEPT DEVELOPMENT

Naval Engineers JournalVolume 103, Issue 4 p. 137-138 ROLE OF SIMULATION IN RAPID PROTOTYPING FOR CONCEPT DEVELOPMENT J. FRED KING PH.D., J. FRED KING PH.D.Search for more papers by this authorDOUGLAS E. BARTON, DOUGLAS E. BARTONSearch for more papers by this author J. FRED KING PH.D., J. FRED KING PH.D.Search for more papers by this authorDOUGLAS E. BARTON, DOUGLAS E. BARTONSearch for more papers by this author First published: July 1991 https://doi.org/10.1111/j.1559-3584.1991.tb01021.xAboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume103, Issue4July 1991Pages 137-138 RelatedInformation

A framework for highly reusable simulation modeling

This paper presents a conceptual framework for simulation modeling which emphasizes model reusability. Reusability is achieved through the provision of separate modeling constructs for physical, information, and control/decision elements of a system. These constructs contribute to a modular environment in which the modeling elements, once created, can be stored in a modeling database and retrieved. While this framework can be implemented within traditional simulation modeling environments, an object oriented modeling environment appears to offer a potentially superior approach. >

Mathematical analysis and digital simulation of the respiratory control system.

Abstract : The report expresses the basic material balance relationships for the lung-blood-tissue gas transport and exchange system in a set of differential- difference equations containing a number of dependent time delays. Additional equations define the chemical details of transport and acid-base buffering, concentration equilibria, and blood flow behavior. Finally, a control function is included defining the dependence of ventilation upon CSF (H(+)), and arterial (H(+)) and PO2 at the carotid chemoceptors. A Fortran program was written for convenient digital simulation of the responses of the system to a wide variety of forcings, including CO2 inhalation, hypoxia at sea level, altitude hypoxia, and metabolic disturbances in acid-base balance. Both dynamic and steady-state behavior of the model were reasonably realistic.