System Simulation Language Research Articles

Development of tritium dynamic transport analysis tool for tritium breeding blanket system using Modelica

Demonstration of the engineering feasibility of tritium breeding, including tritium generation, tritium extraction, tritium control and tritium safety is one of the main objectives of ITER Testing Blanket Module (TBM) Program. As one of TBM concepts, the tritium transport assessment of the China Helium Cooled Ceramic Breeder TBM and its ancillary systems (called test blanket system, TBS) is absolutely vital to understand and analyze the dynamic tritium behaviors in the system in detail according to the ITER operation scenario. Considering the requirements of the tritium transport analysis for the HCCB TBS, an integrated dynamic tritium transport analysis tool has been developed by the system simulation language “Modelica”. The multiple dynamic physics effects are considered in the tool, including the aspects impacting the tritium transport, simplified thermal-hydraulics considering only the linear loss and local loss in fluid, 1-d thermal conduction in solid, hydrogen isotope transport in fluid, 1-d tritium permeation in solid, tritium solution and recombination on solid surfaces, tritium desorption from ceramic breeder etc. A simplified model of the HCCB TBS is modeled to verify the functions and accuracy of this tool. The results, such as dynamic change of tritium concentration/partial pressure in fluids, dynamic change of tritium inventory in solids, tritium permeation fluxes etc., have been obtained, which are preliminary verified at various aspects by comparing with analytical and hand calculations.

PSML: parallel system modeling and simulation language for electronic system level

System-level description languages in electronic system level are domain-specific sequential simulation languages using the shared-everything model in discrete-event modeling and simulation terminology. They implement sequential process-interaction worldview to take advantage of event partitioning for ease of programming and modularity. Therefore, their reference simulators can only be executed on a single physical core. Fast and accurate simulation is highly desirable for efficient and effective system design due to the ever-increasing complexity of embedded and cyber physical systems. Parallel discrete-event simulation (PDES) is the main technique to solve this problem for large-scale system-level models. PDES works based on state space partitioning by using the so-called logical process worldview. This paper proposes parallel system modeling and simulation language (PSML), along with its formalized distributed parallel simulation kernel, that provides execution of hardware models in order to improve simulation speed significantly. It will be shown that the proposed framework results in linear, super-linear speedups ranging from 11 × to 32 × for large-scale, complex PSML models in comparison with the SystemC reference simulator on a 12-core host.

A Novel Approach to Modeling and Verifying Real-Time Systems for High Reliability

This paper proposes a novel approach to modeling and verifying real-time systems for high reliability. To do so, we first extend projection temporal logic to timed projection temporal logic. Further, we define a timed modeling, simulation, and verification language (TMSVL) for real-time systems. As a result, both systems and desired properties can be expressed in TMSVL. In particular, real-time behaviors such as delay, timeout, and interrupt can be formalized. Compared with commonly used property specification language, TMSVL is capable of specifying more sophisticated properties such as quantitative timing properties, interval-related properties, and periodically repeated properties. Moreover, the unified model checking approach to verifying real-time systems via dynamical program execution is implemented. In addition, a case study for modeling and verifying a $\mu$ C/OS-III multitask system with interrupt is conducted to demonstrate how the proposed approach works.

CoSMSOL: Complex system modeling, simulation and optimization language

Complex System Modeling, Simulation and Optimization Language (CoSMSOL) is problem-oriented and designed to run on multi-core computers. This paper provides the system environment of CoSMSOL and proposes the modeling methods of complex system, language text specification, function library, algorithm library, parallel simulation algorithms and intelligent optimization algorithms which support continuous system, discrete system and agent systems. Also, we developed a simulation language compiler of CoSMSOL, which is employed in two case studies generating a multi-entity war gaming system and an aerodynamic spacecraft model. The two cases illustrate main functions and implementation processes of CoSMSOL. The results validate that CoSMSOL is useful to model agent-based system and aerospace system.

Development and application of intelligent system modeling and simulation platform

As a common support of M&S (Modeling and Simulation) applications, M&S language and platform can effectively improve M&S capability for complex objects and systems. This paper proposes an Intelligent system Modeling and Simulation Language (IMSL) which integrates artificial intelligence theory and M&S technology to describe intelligent model structures, behaviors, facts, knowledge, and rules. Meanwhile, an M&S platform is implemented to provide a basic support for M&S of intelligent systems, featured as its convenience, efficiency and problem solving ability. Our research work has been focused on M&S methods and language specification of intelligence systems, intelligent simulation resource libraries and integrated development environment. As an application instance, M&S of a C3I (Command, Control, Communication and Information) system is conducted to evaluate the performance of IMSL and the IMSL platform. And the simulation result proves that IMSL can work effectively in solving practical problems.

A hybrid controller for autonomous vehicles driving on automated highways

This paper addresses the problem of the hybrid control of autonomous vehicles driving on automated highways. Vehicles are autonomous, so they do not communicate with each other nor with the infrastructure. Two problems have to be dealt with: a vehicle driving in a single-lane highway must never collide with its leading vehicle; and a vehicle entering the highway at a designated entry junction must be able to merge from the merging lane to the main lane, again without any collision. To solve these problems, we equip each vehicle with a hybrid controller, consisting of several continuous control laws embedded inside a finite state automaton. The automaton specifies when a given vehicle must enter the highway, merge into the main lane, yield to other vehicles, exit from the highway, and so on. The continuous control laws specify what acceleration the vehicle must have in order to avoid collisions with nearby vehicles. By carefully designing these control laws and the conditions guarding the automaton transitions, we are able to demonstrate three important results. First, we state the initial conditions guaranteeing that a following vehicle never collides with its leading vehicle. Second, we extend this first result to a lane of autonomous vehicles. Third, we prove that if all the vehicles are equipped with our hybrid controller, then no collision can ever occur, and all vehicles either merge successfully or are forced to drop out when they reach the end of their merging lane. Finally, we show the outcome of a highway microsimulation modelled after the Katy Corridor near Houston, Texas: our single-lane highway can accommodate 4000 vehicles per hour with neither drop-outs nor traffic congestion. It is entirely programmed in S hift, a hybrid systems simulation language developed at UC Berkeley by the PATH group. This shows that S hift is a well suited language for designing safe control laws for autonomous highway systems, among others.

1107 連続系シミュレーション用言語をベースにした粒子法解析用言語「悟空(粒子法)」とその応用例

1107 連続系シミュレーション用言語をベースにした粒子法解析用言語「悟空(粒子法)」とその応用例

Vehicle dynamics analysis of eco vehicle using mechanical system simulation language Takehiko Fujioka, Torahiko Yamanouchi (The University of Tokyo), Hiroshi Shimizu (The National Institute for Environmental Studies)

Vehicle dynamics analysis of eco vehicle using mechanical system simulation language Takehiko Fujioka, Torahiko Yamanouchi (The University of Tokyo), Hiroshi Shimizu (The National Institute for Environmental Studies)

A Study on a Elastoplastic Damper Utilizing Continuous Plastic Bending of Thin Metal Rods.

In this paper, a new type of elastoplastic damper utilizing continuous plastic bending of thin metal rods is proposed in order to obtain an elastoplastic damper which yields damping even for a small displacement. The seismic responses of a piping system supported by the elastoplastic damper were calculated using a continuous system simulation language and the effects of the damper on the deflection of the piping system are discussed. The trial damper was made using a thin copper rod, and the resisting force characteristics and fatigue strength of the damper were measured. The seismic responses of an L-shaped pipe supported by the trial elastoplastic damper were measured using an electrohydraulic shaking table. The experimental results were compared with the calculated results.

Motorcycle motion analysis using mechanical system simulation language Hirohide Imaizumi, Takehiko Fujioka, The University of Tokyo, pp. 21–24, 16 figs., 1 table, 3 refs.

Motorcycle motion analysis using mechanical system simulation language Hirohide Imaizumi, Takehiko Fujioka, The University of Tokyo, pp. 21–24, 16 figs., 1 table, 3 refs.

Semiactive Damper Using a Piezoelectric Actuator and a Ball Screw for a Seismic Isolation Device for Machines.

In this paper, a new type of semiactive seismic isolation device for machines is proposed. This isolation device is composed of rubber bearings and semiactive dampers consisting of a ball screw, a brake disk, a brake shoe, a flexure hinge and a piezoelectric actuator. The seismic responses of a machine supported with the isolation device, which is installed on the 5th floor in a 7-story building, are calculated using a continuous system simulation language (FACOM SLCS4), and the effective control condition of the semiactive damper is discussed. An experimental semiactive damper and a model of a machine-isolation device system are made, and the resisting force characteristics of the damper and the seismic response of the machine are measured using an electrohydraulic-type shaking table. The experimental results are compared with the calculated ones, and the effect of vibration isolation of the isolation device is confirmed.

圧電アクチュエータを用いた半能動制御形防振器による配管の地震応答抑制

The authors propose a new type of semiactive damper to control a seismic response of a piping system. The damper is composed of a ball screw and a disk brake with piezoelectric actuators. The brake force is controlled corresponding to the seismic response of the piping or an input acceleration. The damper does not restrict the thermal expansion of the piping because its brake force does not work during a gradual movement. The seismic responses of an L-shaped piping supported with the semiactive damper are calculated using a continuous system simulation language. The restraint effects of the damper are also confirmed experimentally. The results may be summarized as follows : (1) The relative displacement response of the piping can be reduced successfully by the semiactive damper. (2) The semiactive damper has the effect of vibration suppression even by simple control methods such as on-off control and proportional control. (3) The resistance force of the semiactive damper is small compared to that of a mechanical snubber.

Development of an Earthquakeproof Device Using Magnetostrictive Actuators for Piping Systems.

The mechanical snubber is an earthquakeproof device for a piping system under high temperature. It follows a slow displacement of the piping due to thermal expansion, but restrains the piping by a strong resistance force during an earthquake. This strong force can cause elastic failure of grooves on a brake disk, where steel balls are placed. In this report, a new semiactive snubber using giant magnetostrictive actuators and a ball screw is proposed in order to obtain an earthquakeproof device which has less resistance force in comparison with the mechanical snubber. Earthquake responses of a simple beam supported by the semiactive snubber are simulated using a continuous system simulation language, and the restraint effect and the effective controlling condition of the snubber are discussed. The semiactive snubber is built using Terfenol-D (Tb0.3 Dy0.7 Fe1.92-1.95) rods, and its resistance force characteristic is investigated by means of a vibration table.

KBSIM: a system for interactive knowledge-based simulation

The kbsim system integrates quantitative simulation with symbolic reasoning techniques, under the control of a user interface management system, using a relational database management system for data storage and interprocess communication. The system stores and processes knowledge from three distinct knowledge domains, viz. (i) knowledge about the processes of the system under investigation, expressed in terms of a Continuous System Simulation Language (CSSL); (ii) heuristic knowledge on how to reach the goals of the simulation experiment, expressed in terms of a Rule Description Language (RDL); and (iii) knowledge about the requirements of the intended users, expressed in terms of a User Interface Description Language (UIDL). The user works in an interactive environment controlling the simulation course with use of a mouse and a large screen containing a set of ‘live’ charts and forms. The user is assisted by an embedded ‘expert system’ module continuously watching both the system's behavior and the user's action, and producing alerts, alarms, comments and advice. The system was developed on a Hewlett-Packard 9000/350 workstation under the HP-Unix and HP-Windows operating systems, using the Mimer database management system, and Fortran, Prolog/Lisp and C as implementation languages. The kbsim system has great potentials for supporting problem solving, design of working procedures and teaching related to management of highly dynamic systems.

Elastoplastic Damper Using V-Shaped Plates. 1st Report. Seismic Response Analysis of a Base Isolated Building Using the Elastoplastic Damper.

This paper describes the static and dynamic characteristics of a new type of elastoplastic damper and seismic responses of a base isolated building using the elastoplastic dampers. The damper uses two pairs of V-shaped plates and its force-displacement curve is nonlinear with a hardening characteristic in the plastic range. The static force-displacement curve is obtained theoretically, and the dynamically equivalent model which takes into account elasticity, viscosity, plasticity, strain-rate sensitivity and geometry change of the damper is proposed. A seismic isolator consisting of rubber bearings and the elastopladtic dampers is also proposed, and the seismic responses of a 7-story building isolated by this isolator are calculated using a continuous system simulation language (CSSL).

A Simulation Methodology for Evaluating the Reliability, Availability and Performance of the Next European Torus

The operating targets of the Next European Torus (NET) vary over the planned physics and technology phases of operation, which will be cyclic and dynamic. Using the Dynamic Systems Simulation Language a model is described which mimics the cyclic behaviour of the NET over the technology phase together with its dynamic behaviour. The simulation model represents a methodology that can be used to evaluate the reliability, availability and performance of the NET. A number of case studies are presented to demonstrate the underlying philosophy of the approach.

Matrix environments for continuous system modeling and simulation

In any future standard for continuous system simulation lan guages, it is of primary importance that the data and program structures are made sufficiently general and flexible. In this paper, the use of matrix structures in modeling and simulation, and the impact of matrix environments on the design of simulation languages and their experimental frames will be discussed.

An analysis of SIMAN as a general-purpose simulation language for mining systems

ABSTRACT The SIMAN computer language is a general-purpose, discrete-continuous simulation analysis language for modeling a variety of systems. The language has been extensively used for modeling manufacturing systems but has many features that are advantageous in the modeling of mining materials handling systems. The authors have evaluated the language by applying it to an open pit truck/shovel materials handling system. This paper summarizes the results of the application of the model, compares its features with other simulation languages and evaluates its usefulness for simulation of mining systems.

Numerical evaluation of a multi-stream pseudo-random number generator

This paper describes the techniques utilized by the random number generator of a computer simulation system called dynamic systems simulation language (DSSL). This generator has the capability of creating independent number sequences through the use of specific seeds spaced 100 000 numbers apart. The sequences generated by the first 50 streams have been subjected to statistical tests for the investigation of their local properties. The computer implementation of the algorithms used by these tests are provided together with the results.

Resisting force characteristics of a mechanial snubber and its restraint effect on beam deformation.

A mechanical snubber is used to restrain piping systems in nuclear power plants during an earthquake. It has nonlinearities in both load (or exciting amplitude) and frequency response, so it will be very difficult to analyze the resisting force characteristics of the mechanical snubber theoretically. In this report, the equation of motion of the mechanical snubber is derived and digital simulations of snubber dynamic characteristics over a frequency range are carried out using the Continuous System Simulation Language (CSSL). Also, the restraint effect of the mechanical snubber applied to a simple beam is discussed both numerically and experimentally. The beam is replaced by a lumped mass system and CSSL is used to perform the digital simulations