Integrated Simulation Environment Research Articles

Remote Operation SW for USV: Part II. Simulation Development

For contingencies occurring in a complex marine environment, Unmanned Surface Vehicle (USV) has to recognize the situation and decide behaviors, and plan the following actions through the Integrated Mission Planning Process. Therefore, researches are actively being carried out about it. However, since it is difficult to test the actual USV with the mission planning process, it is necessary to develop a virtual experimental environment based on Modeling & Simulation (M&S). In this study, we developed an integrated simulation environment capable of simulating and analyzing the overall mission of USV. In Part I, we modelled the USV Integrated Mission Planning Process and in Part II, we developed an experimental framework and interface for loading them. In addition, we verified the suitability of this model through scenarios and defined the Mission of Effectiveness (MOE) concept for USV mission analysis.

Implementing a Simulation Model for the Evaluation of BGP Updates Impact on Real-Time Applications

Border Gateway Protocol (BGP) is the actual routing inter-domain protocol in the Internet. The size, heterogenity and changebility that characterize todays Internet put always increasing requirements on BGP performance. The research community has already reported the unwanted characteristics of BGP like low integrity and slow convergence through theoretichal analyzes andd empirical measurements. Simulations allow for more realistic and flexible experiments than the theoretichal approach and also lower costs than the measurements in real life environments. The first part of this work describe theoretically characteristics and problems related to BGP nd also expectations of the today Internet users to real time applications (like VoIP). The second part concentrates in identifying and implementing of the elements for creating an integrated simulation environment for evaluating dhe effects of slowconvergence of BGP in these applications. At last it is evaluated the created environement through some small scale simmulations that try to model the now days Internet Structure.

A Preliminary Design System for Turbine Discs

AbstractIn order to improve product development cycle, design engineers use multidisciplinary analysis tools which allow for better productivity. This paper covers the development of new tools to improve the preliminary design phase of turbine disc, being a critical part of aircraft engines. First, a new single platform D&A (Design & Analysis) tool integrating commercial CAD (Computer Aided Design) and FEA (Finite Element Analysis) software processing in batch mode is presented. This integrated architecture leads to a real improvement, enabling a cohesive single integrated simulation environment that offers significant time reduction on user manipulation and execution. An optimization of disc geometry is then performed by using different optimization algorithms and configurations for a given disc parameterized model. The results show potential improvement over the current preliminary rotor discs for life and burst limited design. Finally, optimal curves obtained by developing HPT (High Pressure Turbine) disc reference charts, indicate how to get the minimum weight for given mechanical performance without running any structural analysis. These new tools supporting disc design have allowed improvement of disc life and durability leading to a reduction of preliminary design phase duration.

Implementing a Simulation Model for the Evaluation of BGP Updates Impact on Real-Time Applications

Border Gateway Protocol (BGP) is the actual routing inter-domain protocol in the Internet. The size, heterogenity and changebility that characterize todays Internet put always increasing requirements on BGP performance. The research community has already reported the unwanted characteristics of BGP like low integrity and slow convergence through theoretichal analyzes andd empirical measurements. Simulations allow for more realistic and flexible experiments than the theoretichal approach and also lower costs than the measurements in real life environments. The first part of this work describe theoretically characteristics and problems related to BGP nd also expectations of the today Internet users to real time applications (like VoIP). The second part concentrates in identifying and implementing of the elements for creating an integrated simulation environment for evaluating dhe effects of slowconvergence of BGP in these applications. At last it is evaluated the created environement through some small scale simmulations that try to model the now days Internet Structure.

전압계측기반 CVR제어 알고리즘 개발 및 검증을 위한 RTDS-MATLAB 연동 시뮬레이션 환경 개발

CVR은 계통의 전압을 감소시켜 소비 전력을 줄이는 기술로, 과거 많은 실증과 연구가 진행되어 왔다. 최근, SCADA 기반 또는 AMI 기반의 VVC가 개발되면서 CVR이 중요한 운영 방식이 되었다. CVR은 다양한 계측기를 사용하여 폐루프 제어(closed loop control)방식으로 최적 VVC제어 지령치를 결정한다. 본 논문에서는 전압 계측기반 CVR제어 알고리즘 개발 및 검증을 위한 RTDS-MATLAB 연동 환경을 구현하였다. RTDS를 이용하여 배전 계통의 전압제어기기들을 모델링하고 MATLAB으로 RTDS의 모의 계통의 전압을 계측하고 제어할 수 있는 제어기를 구성하였다. 무효전력 제어기기인 캐패시터는 계통의 전압을 평탄화하고 계통의 전압 기반으로 OLTC의 탭 제어를 하여 계통의 전압을 낮추는 제어 알고리즘을 MATLAB을 통해 구현하였다. 시뮬레이션을 통해 제안한 시스템을 검증하였다. CVR is a technique for reducing power consumption by reducing the voltage of the system and many demonstrations and studies have been conducted in the past. Recently, SCADA-based or AMI-based VVC have been developed and the CVR is used as an important operation mode. Using a variety of instruments, CVR determines the optimal VVC control references by closed loop control. In this paper, we implemented RTDS-MATLAB integrated simulation environment for development and verification of CVR control algorithm based on voltage measurement. The voltage control device of distribution system was modeled using RTDS and MATLAB has constructed a controller that can measure and control the voltage of the simulation system of RTDS. After the capacitor, which is a reactive power control device, flattens the voltage of the system, the control algorithm reduces the voltage of the system by tap control of the OLTC based on the flatten voltage. The proposed system was verified by simulations.

Stochastic Simulation Service: Bridging the Gap between the Computational Expert and the Biologist.

We present StochSS: Stochastic Simulation as a Service, an integrated development environment for modeling and simulation of both deterministic and discrete stochastic biochemical systems in up to three dimensions. An easy to use graphical user interface enables researchers to quickly develop and simulate a biological model on a desktop or laptop, which can then be expanded to incorporate increasing levels of complexity. StochSS features state-of-the-art simulation engines. As the demand for computational power increases, StochSS can seamlessly scale computing resources in the cloud. In addition, StochSS can be deployed as a multi-user software environment where collaborators share computational resources and exchange models via a public model repository. We demonstrate the capabilities and ease of use of StochSS with an example of model development and simulation at increasing levels of complexity.

Fulfilment of Grid Code Obligations by Large Offshore Wind Farms Clusters Connected via HVDC Corridors

The foreseen high penetration levels of wind power will force the systems operators to apply restrictive constraints on wind power plants. The ability of offshore wind clusters, which are connected via HVDC, to fulfill the grid codes, especially those related to voltage stability is investigated. This came in the frame of a project to develop an integrated and practical tool to design offshore wind clusters (EERA-DTOC). The applied case studies examine the system stability during and after severe disturbances, and the compliance with the grid codes. Additionally, this paper explains the applied procedure to utilize the outcomes of Net-OP tool, which proposes an optimized topology to connect the wind power clusters to the interconnected power systems. The integrated simulation environment, namely, PSS/E, is used to implement a highly detailed and dynamic model based on the recommendations of Net-OP tool. The results confirm that wind farm clusters respond to faults and disturbances as desired by the grid codes.

Active Vivaldi Antenna Timed-Array for Ultra-Wideband 3D Beamforming

Background: This paper presents a three-dimensional antenna array for electronic high-resolution beam spatial scanning. System and Design Structure: The system consists of five identical elements, arranged in a cross shape (3+3), where each element is formed by a Vivaldi planar antenna equipped with a Ultra Wide Band (UWB) pulse generator (PG), connected to a programmable delay circuit (PDC). The Vivaldi antennas were designed with copper and a Roger (RO3203) substrate, while the PG and PDC were designed using the 0.18μm CMOS Standard process. The project was designed in an integrated simulation environment (electric + electromagnetic), combining LTSpice 4, MicroWind 3.5 and CST MW Studio 2011 design tools. Monte Carlo simulations showed fully consistent results with those of theoretical models. The main lobe has a gain of 13dB, 28º × 27º angular width, a beam steering between 31º and -24º for θ, and between 29º and -29º for the φ angles at 6.2GHz of center frequency.

An Integrated Simulation Environment for Testing V2X Protocols and Applications

Implementation of Vehicle-to-everything (V2X) communication technologies, for traffic management, has been envisioned to have a plethora of far-reaching and useful consequences. However, before any hardware/software infrastructure can be developed and implemented, a thorough phase of testing is warranted. Since actual vehicles and traffic conditions cannot be physically re-constructed, it is imperative that accurate simulation tools exist in order to model pragmatic traffic scenarios and communication amongst the participating vehicles. In order to realize this need of simulating V2X technology, we have created an integrated simulation environment that combines three software packages, VISSIM (traffic modelling), MATLAB (traffic management applications) and NS3 (communication network simulation). The combination of the simulators, has been carried out in a manner that allows on-line exchange of data amongst them. This enables one to visualize whether a traffic management algorithm creates the desired effect and also the efficacy of the communication protocol used. In order to test the simulator, we have modelled the Green Light Optimized Speed Advisory (GLOSA) application, whose objective is communication of the present traffic signal phase information to oncoming vehicles using a transmitting unit installed on the signal itself. This information will allow the vehicles to calculate the desired speeds necessary to cross the relevant intersection without stopping. Therefore, a “Green Wave” can be created for all vehicles without the need to coordinate traffic signal timers, which can be rather complex in a multiple intersection traffic corridor.

M&S기반 무인지상전투차량 설계를 위한 통합모의실험환경 아키텍처모델

M&S (Modeling & Simulation) based design is widely accepted for the development of the future weapon system with better performance in a cheaper and faster way. Integrated simulation environment (ISE) is needed for the M&S based design. On the ISE, system engineers can not only verify design options but also validate system requirements. In this paper, we propose architectural models of the integrated simulation environment (ISE) which incorporates mission effectiveness M&S (Modeling & Simulation), system performance M&S, the optimization model of integrated performances, digital mockup and virtual prototype. The ISE architectural models may be used to implement the ISE for the development of the future unmanned ground combat vehicle.

Simulation integration: using multidatabase systems concepts

This paper considers the challenge of designing a framework that supports the integration of multiple existing simulation models into an integrated simulation environment (multisimulation). We aim to facilitate the process of fusing together the independently created simulators into an integrated simulation environment wherein we can model and execute complex scenarios involving multiple simulators. In this paper, we focus on solutions for the synchronization problem in multisimulation to orchestrate consistent information flow through multiple simulators. In particular, we provide: (1) a transaction-based approach to modeling the synchronization problem in multisimulations by mapping it to a problem similar to multidatabase concurrency; we express multisimulation synchronization as a scheduling problem where the goal is to generate “correct schedules” for time advancement and data exchange across simulators that meets the dependencies without loss of concurrency; (2) a hybrid scheduling strategy which adapts itself to the “right” level of pessimism/optimism based on the state of the execution and underlying dependencies. We also develop two key optimizations: (a) efficient checkpointing/rollback techniques; and (b) relaxation model for dependencies which guarantees bounded violation of consistency to support higher levels of concurrency. We evaluate our proposed techniques via a detailed case study from the emergency response domain by integrating three disparate simulators: a fire simulator (CFAST), an evacuation simulator (Drillsim) and a communication simulator (LTEsim).

Frequency support capability of variable speed wind turbine based on electromagnetic coupler

In the variable speed wind turbine based on electromagnetic coupler (WT-EMC), a synchronous generator is directly coupled with grid. So like conventional power plants WT-EMC is able to support grid frequency inherently. But due to the reduced inertia of synchronous generator, its frequency support capability has to be enhanced. In this paper, the frequency support capability of WT-EMC is studied at three typical wind conditions and with two control strategies—droop control and inertial control to enhance its frequency support capability. The synchronous generator speed, more stable than the grid frequency which is the input signal for Type 3 and Type 4 wind turbine frequency support controller, is used for the calculation of WT-EMC supplementary torque command. The integrated simulation environment based on the aeroelastic code HAWC2 and software Matlab/Simulink is used to build a 2 MW WT-EMC model and study the frequency support capability of a wind farm consisting of WT-EMC.

Establishing the Digital Model of Hydraulic System in Simulation Vibration Table

Based on the analysis of the development, defects and motion of present hydraulic system vibrating table, it is divided into several single disciplinary system modes which are organic related in this paper. Establishing unified digital model in integrated simulation environment through analyzing the function of these models, which will guide the design of digital vibration table system.

토크 벡터링을 적용한 전기차의 선회 성능 평가에 관한 연구

EV(Electric Vehicle) has many benefits such as prevention of global warming and so on. But due to driving source changing from combustion engine to battery and e-motor, new R&D difficulties have arisen which changing of desired vehicle performance and multidisciplinary design constraints by means of strong coupled multi-physics domain problems. Additionally, dynamics performances of EV becomes more important due to increasing customer`s demands and expectations for EV in compare with internal combustion engine vehicle. In this paper suggests model based development platform of EV through integrated simulation environment for improving analyse & design accuracy in order to solve multi-physics problem. This simulation environment is integrated by three following specialized simulation tools IPG CarMaker, AVL Cruise, DYMOLA that adapted to each purpose. Furthermore, control algorithm of TV(Torque Vectoring) system is developed using independent driven e-motor at rear wheels for improving handling performance of EV. TV control algorithm and its improved vehicle performances are evaluated by numerical simulation from standard test methods.

An integrated cyber-physical simulation environment for smart grid applications

The concept of Cyber-Physical Systems (CPSs), which combine computation, networking, and physical processes, is considered to be beneficial to smart grid applications. This study presents an integrated simulation environment to provide a unified platform for the investigation of smart grid applications involving power grid monitoring, communication, and control. In contrast to the existing approaches, this environment allows the network simulator to operate independently, importing its results to the power system simulation. This resolves conflicts between discrete event simulation and continuous simulation. In addition, several data compensation methods are proposed and investigated under different network delay conditions. A case study of wide-area monitoring and control is provided, and the efficiency of the proposed simulation framework has been evaluated based on the experimental results.

Modeling and simulation of software architecture in discrete event system specification for quality evaluation

Software quality is an important issue in software engineering. The evaluation of software architecture is crucial to achieve quality scenarios, which reduces development and maintenance costs. This work presents a discrete event simulation environment for the software architecture assessment considering both functional and quality aspects. Discrete event system specification (DEVS) formalism and the underlying framework are used to specify the simulation elements. DEVS is based on the system theory and follows the engineering and object-oriented fundamentals to construct complex dynamic systems. The proposed environment is built in a modular and hierarchical way that provides scalability and reusability advantages. Although the proposal is focused on three quality attributes and a few metrics, this approach enables the definition of new elements and metrics related to other quality attributes that can be visible at runtime. A traditional architecture illustrates the proposal, where preliminary computational experiments for this real software system and concrete quality scenarios demonstrate the feasibility of the integrated simulation environment for the software architecture evaluation. In addition, a discussion shows how the results could help architects make design decisions to improve software quality during development.

Designing an Introductory FPGA-Based Embedded System Laboratory

In this paper, we present a series of experiments useful in designing an Embedded System Laboratory. The experiments are built around the Spartan3 XC3S400 manufactured by Xilinx. The necessary code is written in the Very High Speed Integrated Circuit Hardware Description Language (VHDL). Integrated Simulation Environment (ISE) Version 9.1i suite is used for software development which is one of the Electronic Design Automation (EDA) tool offered by the Xilinx Company. It gives a good beginning for students who want to work on Spartan 3 XC3S400.

Recent advances in dynamic modeling of HVAC equipment. Part 2: Modelica-based modeling

This article is the second in the two-part series examining recent advances in the dynamic modeling of HVAC systems, which can be challenging due to the multi-physical and multi-scale processes of such systems. Part I reviewed the progress in dynamic modeling of major types of HVAC equipment. Part II presents a detailed review of dynamic modeling of HVAC equipment using Modelica, an object oriented modeling platform that has demonstrated potential in addressing HVAC equipment challenges. The Modelica-based modeling platform offers some desirable features, such as object-oriented and acausal modeling, that could significantly facilitate modeling efforts and reduce the time of model development. Currently, there are many numerically robust and efficient integrated simulation environments that support the Modelica-based modeling platform, such as Dymola, SimulationX, and MapleSim. This article reviews historical and recent modeling and simulation tools, and later examines previous work on the Modelica-based dynamic modeling of HVAC equipment. It also presents current issues and possible future directions of dynamic modeling for HVAC equipment.

A Novel Wind Turbine Concept Based on an Electromagnetic Coupler and the Study of Its Fault Ride-through Capability

This paper presents a novel type of variable speed wind turbine with a new drive train different from the variable speed wind turbine commonly used nowadays. In this concept, a synchronous generator is directly coupled with the grid, therefore, the wind turbine transient overload capability and grid voltage support capability can be significantly improved. An electromagnetic coupling speed regulating device (EMCD) is used to connect the gearbox high speed shaft and synchronous generator rotor shaft, transmitting torque to the synchronous generator, while decoupling the gearbox side and the synchronous generator, so the synchronous generator torque oscillations during a grid fault are not transmitted to the gearbox. The EMCD is composed of an electromagnetic coupler and a one quadrant operation converter with reduced capability and low cost. A control strategy for the new wind turbine is proposed and a 2 MW wind turbine model is built to study the wind turbine fault ride-through capability. An integrated simulation environment based on the aeroelastic code HAWC2 and software Matlab/Simulink is used to study its fault ride-through capability and the impact on the structural loads during grid three phase and two phase short circuit faults.

Using an integrated simulation environment for the risk based design of advanced driver assistance systems

When designing new Advanced Driver Assistance Systems (ADAS), the existing guidelines like the RESPONSE 3 Code of Practice imply intense testing of the system prior series production. Within the EU-FP7-Project ISi-PADAS a new methodology of risk based design has been established which includes an integrated simulation platform. This integration enables intense testing of new prototypes in an accelerated way and therefore enhances the design process while directly combining the simulation results with a risk matrix.This paper describes the new methodology while focussing on the software framework and the procedure of risk assessment in detail. It shows the general approach as well as the appropriate steps taken for an ADAS prototype developed in the context of ISi-PADAS.