Research on Key Technologies of Event-driven Distributed Cooperative Simulation

Research and design of simulation and verification system of intelligent expressway based on ETC big data

Interactive Problem Solving Environments (PSEs) offer an integrated approach for constructing and running complex systems, such as distributed simulation systems. New distributed infrastructures, like the Grid, support the access to a large variety of core services and resources that can be used by interactive PSEs in a secure environment.We are experimenting with Grid access for interactive PSEs built on top of the High Level Architecture (HLA), a middleware for interactive simulations. Our current approach is such that once a PSE simulation has been executed in the framework, mechanisms from both HLA and Grid middleware are used to broker resources, for job submission services, performance monitoring services, and security services for efficient and transparent execution.We are experimenting with the Web-based Open Grid Services Architecture (OGSA) for HLA RTI Federate registration and discovery, as well as for data transmission. We have found that Grid Services give the possibility to allow for dynamic modification capabilities of HLA Federates, though the dynamic discovery of Federates and the use of Service Data (metadata) for service introspection is not trivial. Also, we have found that opening many data transmission channels between HLA Federates to one destination affects the number of connections you can make with other destinations.KeywordsPSEinteractiveGridOGSAHLA

Fine-Grained Parallel and Distributed Spatial Stochastic Simulation of Biological Reactions

Based on the analysis of the broad band wireless communication, we design a wireless terrain network with some different subnet of satellite, microwave, LTE, and so on. OPNET provides a virtual network environment, through the modeling of the network. We give the simulation flow of the wireless communication. It designs the station node and satellite node, and builds a simulation system for the broad band wireless communication by OPNET. According the wireless communication topology, it realizes the network simulation system with six zone subnets which contain six single users and two communication vehicles. It contains the communication satellites which use the transparent transponders. The simulation system can display the dynamic route by the simulation system. It also can analyze the performance and efficiency of the wireless system with the parameters, such as: throughput, delay, processing delay, Packet Loss Ratio. It can use “Failure Recovery” module in the simulation system and set the parameters and analyze the communication system influence.

This tutorial has two purposes: to show how the features of CLOS affect a design and to describe the design of a general-purpose simulation system. The tutorial is designed for those who want to understand the practical importance of the unique features of CLOS and also those who would like to learn how to use or build object-oriented simulation systems. The tutorial emphasizes the underlying model of object-oriented programming in CLOS and distinguishes it from other models. It also describes the requirements of a simulation system and the design of DEVS-CLOS, a publicly available simulation system. DEVS-CLOS is an extension to CLOS that supports modeling and simulation. It supports visualization, supports hierarchical design of simulations, allows first-order logic in models, and supports adaptive system simulation. The tutorial shows how a system like DEVS-CLOS can be used to solve typical simulation problems, and how CLOS concepts like multimethods, multiple inheritance, pre- and post-methods and dispatching algorithms were used in the design of DEVS-CLOS.

A simulation system was established in the Matlab/Simulink environment based on the bionic underwater vehicle propelled by multiple undulating fins. It was composed of motion and attitude controller and plant model including 6DOF rigid body kinetic model, carrier's hydrodynamic model, and multiple undulating fins' hydrodynamic model. All parts of the simulation system were designed in detailed, and a layered control system was put forward. Finally, the performance of the control channels for speed, depth and yawing were simulated in terms of the real design parameters and hydrodynamic coefficients. Results show that the simulation system has important significance to research on the dynamic of the bionic underwater vehicle and verify the design of control system.

Strap-down inertial navigation system (SINS) is widely used in military field, to facilitate the study of SINS algorithms and various coupled navigation algorithms, a simulation system of SINS is designed. Based on modular design, with good portability and expansibility, the system consists of four independent modules: analysis module of motion state, trajectory simulator, IMU simulation module and SINS calculation module. With graphical interface, the system can control every motion state of the trajectory, which is convenient to generate various trajectories efficiently. Using rotation vector attitude algorithm to process simulation data, experiment results show that the attitude, velocity and position error is consistent with the theoretical value, which verifies the rationality of the simulation model and the availability of the simulation system.

This paper designs and implements a simulation system that can verify the planning algorithms such as table tennis trajectory planning and robot leg movement planning. The simulation system and the humanoid robot’s control system are connected based on the RTnet real-time Ethernet protocol. The table tennis game of the humanoid robot is implemented using the simulation of the forward and inverse kinematics of the robot arm, the hitting planning, and the forward and inverse kinematics of the robot leg.

This paper introduced the background of LNG powered ship reliquefaction plant and its working principle, established the calculation model of simulation system, taking the VLCC ship LNG powered ship as the mother ship, provided the thermodynamic calculation flow chart, developed the software for the operation simulation system and the developed the assessment system and the equipment management system. This software can simulate the operation process and carry out the numerical calculation. It is good for the purpose of training students and has great reference value for research.

Global virtual time (GVT) is used in parallel discrete event simulations to reclaim memory, commit output, detect termination, and handle errors. Mattern 's [I] has proposed G VT approximation with distributed termination detection algorithm. This algorithm works fine and gives optimal performance in terms of accurate GVT computation at the expense of slower execution rate. This slower execution rate results a high GVT latency. Due to the high GVT latency, the processors involve in communication remain idle during that period of time. As a result, the overall throughput of a discrete event parallel simulation system degrades significantly. Thus, the high G VT latency prevents the widespread use of this algorithm in discrete event parallel simulation system. However, if we could improve the latency of GVT computation, most of the discrete event parallel simulation system would likely take advantage of this technique in terms of accurate G VT computation. In this paper, we examine the potential use of tress and butterflies barriers with the Mattern's GVT structure using a ring. Simulation results demonstrate that the use of tree barriers with the Mattern's GVT structure can significantly improve the latency time and thus increase the overall throughput of the parallel simulation system. The performance measure adopted in this paper is the achievable latency for a fixed number of processors and the number of message transmission during the G VT computation.

Vehicle movement may critically influence ride comfort, so reliable analysis and simulation systems are needed in the design of a vehicle-occupant system. In order to predict the performance of a vehicle-occupant system, it is necessary to consider the vehicle and the occupant as a dynamically coupled oscillation. This paper is concerned with theoretical analysis and verification of the simulation system of vehicle-occupant dynamic interaction. The mathematical model has twelve degrees of freedom : a vehicle model with four masses is six degrees of freedom, and an occupant model with four masses, the hinged beam model, six degrees of freedom. The random roughness of an actual highway surface has been taken into account in the simulation system. Simulated results almost agreed with experimental values. This simulation system can be used as a tool to investigate the effects of physical variables that influence automobile seat ride comfort. The effects of seat characteristics, stable posture of seat system for passengers, and engine shake on human dynamic behavior can be investigated.

Scientific visualization is a method of computing which provides an insight into the visualized-simulated system. Recently, the simulation of different physical processes and systems has developed. Furthermore, the simulated system getting bigger and more sophisticated. Recently, the authors proposed a new hybrid architecture local area network (Hybrid-Meshnet). The Hybrid-Meshnet allows an insertion of data links into existing LANs. The authors simulate, investigate and visualize the operation and performance behaviour of Hybrid-Ethernet in comparison with conventional Ethernet. Through the event-driven simulation, a computer animation of the network operation is visualized. The simulator, in addition, generates the required data which is displayed as a 3D animated graph for performance investigation. Simulation results indicate that the performance of the Hybrid-Ethernet is improved with respect to the pure Ethernet. Moreover, the visualization technique is very efficient for seeing the unseen through simulation process.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

At the lunar patrol detection stage, effective and accurate inspection path planning is the prerequisite and basis for lunar missions. This article designed and implemented lunar surface inspection simulation and validation system, the system is to verify the part inspection technology by computer simulation technology, with a view to provide some technical support for autonomous navigation, autonomous mission planning, and related research of the future Chang'e-third surface inspections.

Design of an advanced electric power distribution systems using seeker optimization algorithm

The Graduate Automotive Technology Education (GATE) Center at the University of Tennessee, Knoxville (UTK) offers courses addressing the simulation, modeling, and control system design of hybrid electric vehicles (HEV). In the Spring of 1999 such a course was conducted to support the UTK FutureCar Challenge entry for 1999. The vehicle modeled is a Dual-configuration Hybrid Electric Vehicle (DHEV) which uses a planetary power-split device similar to the Toyota Hybrid System used in the Toyota “Prius”. The goals of the course included the development of a real-time simulator that could incorporate actual vehicle control hardware in the simulator loop. This “control-hardware-in-the-loop” (CHIL) configuration was used for simulation, control system design, and troubleshooting. This approach allows the simulation of normal vehicle operating conditions as well as emergency fault handling situations in which it may not be desirable to subject the actual prototype vehicle to a given test condition. Additionally, it is possible to do a great deal of control system testing and development without an operating vehicle.