Volume 14    Number 6    (2002)

 

Title Author Abstract
Multi-domain Integrated Product Modeling and Simulation Technology of Mechatronic System MIN Chun-ping, DOU Wen-hua     Complex mechatronic systems such as airplane, car, machining center and robot, are increasingly taken the approach of network-based designing and manufacturing on the Internet. The research on mechatronic systems’ integrated product modeling is now an international hotspot of CAD domain. According to the similarities among engineering subsystems including mechanical, electronic, hydraulic, etc., a component–based abstract mechatronic systems’ architecture is put forward, the port-based multi- energy-domain-integrated component model is given as well as its formalizing description, which consists of function, behavior, form, interface and constraints. Based on the component model, a multi-energy-domain-integrated modeling and simulation framework for mechatronic product is constructed, which can support the evolving process of distributed, collaborative, component-based and simulation-based design of mechatronic systems very well. Finally, a simple example is introduced to illustrate the main ideas.
Research on STEP Product Model in Virtual Prototyping Development ZHOU Hong-wei, WANG Wei-ping,

WANG Hao

    This paper introduces a method that uses STEP product data model to support exchange and share of product information between applications in virtual prototyping development. The process from the creation of product data model to the data exchange between applications is explained. A solution to model manipulation and object retrieve is given in an application using AP203.
Research on the Physical Model of Multiple Variable Refrigerant Volume Air-conditioning System SHAO Shuang-quan, SHI Wen-xing,

LI Xian-ting & YAN Qi-sen

    Based on the theory of system and similarity, the structure, physical model, performance of operation and adjustment and so on about single variable refrigerant volume refrigeration system (SVRV) and multiple variable refrigerant volume refrigeration system (MVRV) are studied and compared. The analysis and comparison show that SVRV is the abstraction and simplification of MVRV while MVRV is the expansion and extension of SVRV. SVRV and MVRV systems can be uniformed with gas liquid two-phase fluid network, which will be helpful for developing MVRV systems, including optimal design, selection of types and performance measurement on VRV systems.
Modeling and Simulation of Hydraulic System of Water Gate Using the Distributed Physical Net Modeling Approach ZHAO Jian-gang, LI Zhao-hui     Based on the analysis of the physical structure and the operating principle of the hydraulic system of water gate, a model of this hydraulic system is built using the distributed physical net modeling approach. The tests of simulation were carried out on the platform of Matlab with Simulink. The simulation results show that this method is a good way to simulate the hydraulic system.
Study on the Model of Intercepting Decision for Multi Channel Surface to Air Missile Weapon System ZHOU LinZHANG Wen

LOU Shou-chunZHAO Jie

    Multi channel surface to air missile weapon system has the ability to lead multi missiles to catch multi objects. Air missile weapon system has been the main means for our national air defense. The accuracy and rationality of intercepting decision have a great effect on the result of air defense. Based on the 0-1 integer programming, the optimizing decision model is proposed in this paper. It can guarantee the rationality and utility of intercepting decision.
Multipath Time Delay Estimation Based on Adaptive Parameters Approach Using Fourth-Order Cumulants LIU Ying, WANG Shu-xun, WANG Ben-ping     Taking into account the multi-channels disturbance and spatially correlated Gaussian, multipath time delay estimation based on adaptive parametric approach using fourth-order cumulants is proposed in this paper. Multi-path time delays are estimated precisely with this approach, and spatially correlated Gaussian noises can be suppressed effectively. The simulation examples are presented to demonstrate the effectiveness of this novel approach. This multipath time delay estimation approach based on adaptive parameters approach can be used to location targets in sonar and radar system.
Asymptotic Stability Properties of Radau IIA Methods for the Pantograph Delay Equation LI Dong-song, LIU Ming-zhu     This paper deals with the asymptotic stability analysis of Radau IIA methods for the pantograph delay equation. In recent years stability properties of numerical methods for this kind of equation have been studied by numerous authors who have considered meshes with fixed mesh. In general the developed techniques give rise to a non-ordinary recurrence relation. In this paper we study constrained variable stepsize schemes, suggested by theoretical and computational reasons, which lead to a non- stationary difference equation. We prove that Radau IIA methods are H-stable.
Genetic Algorithms and its Application in RoboCup XIA Wei-feng, FEI Min-rui      This paper summarizes the research of Genetic Algorithms application in RoboCupfrom the view of genetic computation, genetic programming and genetic learning. One of hybrid intelligent agent architecture is also proposed, and it can be a way of reference solution for further study.
Modeling Simulation Environment of Real-time Operating Systems with UML LIU Yu-feng, LI Ren-fa, MO Tie-qiang,

SUN Ting

    Scheduling policy is a hot spot in research of modern real-time OS. The evaluation of scheduling policy is the difficulty in the research. In order to verify the validity of scheduling policy, we designed a virtual simulation system for the process scheduling of OS by the use of UML method. This paper presents the simulation system taking virtual time for driver, taking task for the underlying scheduling object and taking random producer for producer of system load. This paper can be used as a paradigm in the modeling with UML (Unified Modeling Language).
On Interconnection Technology of High Level Architecture Multi-Federations HAIO Jian-guo, ZHAO Xing-feng,

HUANG Jian, HUANG Ke-di

    The High Level ArchitectureHLAsupports the interoperation between federates joined in a single federationAs the scale of simulation systems expanding, the reusability of federates or even of federations becomes very important for rapidly enlarging systems. Therefore, the interconnection of multiple federations is desiderated to be solved. This paper first analyses the reusability and interoperation of the HLA, then discusses the four basic methods to implement the interconnection of multiple federations, finally presents an approach of hierarchical federations.
Research and Implementation of Automatically Generating Federate Software Framework from High Level Architecture Object Model YIN Juan, HAO Jian-guo, HUANG Ke-di     In the federation development based on HLA/RTI, how to minimize the level of HLA understanding required of federate developer and simplify the process of creating federate is an urgent job. This paper analyses the software configuration and program flow of typical federates and gives an approach of generating federate software framework from HLA Object Model (FOM or SOM). A tool based on the approach – FedWizard, which can automatically generate federate software framework that is C++ code was implemented.
Cooperative Tactical Decision Methods for Multi-aircraft Air Combat Simulation DONG Yan-fei, FENG Jing-lei,

ZHANG Heng-xi

    By introducing the air combat cooperative tactical decision, a model of air combat situation and threat assessment model —— a threat index method, is presented. Then the steps for target assignment and the munitions allocation model are proposed. Finally, an application example is given, and the results show that the methods used in this paper can be used effectively in air combat cooperative tactical decision.
Study on Distributed Interactive Simulation System for Acoustic Warfare SHEN Yu-li, SHEN Yun-tao, ZHAO Jun-wei, Guo Lei, ZHANG Yun-long     Under the background of modern sea fight, the design and software implementation of the Acoustic Warfare (AW) simulation system are studied, which is based on the technology of distributed interactive simulation and modern communications. This system can be used as a platform for the performance testing of the underwater weaponry or for the usual tactics drilling. Considering the demands of the acoustic warfare system, the arguments focus on the systematical scheme, the interaction and synchronicity of simulation nodes supported by computer network technology, and distributed multimedia database supported subsystem modeling.
Collision Detection for Distributed Virtual Environment SUN Li-xin, ZHU Chang-qian, SUN Ge-wei, ZHUANG Yong     Because entities and avatars belong to the different workstation, collision detection for distributed virtual environment has characteristics of completeness and uniqueness, namely that two sides of collision have once and only once response to a collision. In this paper, we analyze shortcomings of existing algorithm in detail, and then propose a mended algorithm to ensure uniqueness. Also this new algorithm can be used with DR technique together.
A Combined Auralization and Visualization System for Enclosed Spaces ZENG Xiang-yang, CHEN Ke-an, SUN Jin-cai     Both auralization and visualization are very important for building up a virtual sound environment. In this paper, we integrate the basic principle of geometrical acoustics, the computer technique and the theory of signal processing to design a combined auralization and visualization system (CAVS). We describe in detail the main algorithm and the realization of the system. The execution of the application and the modeling result show preliminarily that our program not only has the function of visualization, but also can produce credible virtual sounds.
Vision-based Registration Algorithm for Augmented Reality Using Optical Flow CHEN Jing, WANG Yong-tian, SHI Qi,

YAN Da-yuan

    In order to solve the problem of system delay in augmented reality, an algorithm is proposed to estimate the motion parameters of the color markers using optical flow, so that the position and the orientation between the camera and the dynamic object can be determined in real time according to the method of four-point registration and the pinhole model of camera.  The algorithm is applied in an augmented reality system with a video see-through head-mounted- display (HMD).  The system has a simple structure, requires only a single CCD camera and a few markers with different colors, and yields accurate 3D registration results.  It can work at long ranges and is applicable to outdoor augmented reality applications.
A New Multimode Perceptual Method for 3D Vortex Structure BAO Jin-song, JIN Ye, MA Deng-ze, YAN Jun-qi     Computational fluid dynamics is becoming increasingly important for evaluation of design concepts in the product development process. Scientific visualization provides a very efficient way to insight into the performance of products. Yet traditional visual technology only passes information in vision, limitation of multi-vision, full view and interaction prevents us from the insight into the process of product development. In this paper we present a new method for combining the vision, auralization and haptic of the vortices of a streamline in a vector field. This paper emphasizes the multimode to enhance vertical feature extraction, vortex feature visualization combined sonification and haptic visualization. We are developing a visualization tool which incorporates virtual reality techniques of the interactive exploration of the large scalar and vector data sets. Meanwhile we implement the technique to design and evaluate a new type air-flow pipe for a car air-conditions manufactory.
A View-dependent Multi-resolution Terrain Simplification Based on Adaptive Quadtrees HUAI Yong-jian, HAO Chong-yang,

FAN Yang-yu, LUO Guan, ZHANG Xian-yong

    Terrain rendering is widely used in Games, VR, Simulation, GIS, etc. We present a simple and rapid algorithm of real-time multi-resolution terrain rendering with high resolution texture mapping. It uses view-dependent level-of-details (LOD) algorithm to simplify the DEM terrain. The LOD mesh is based on adaptive Quadtree, which can generate successive LOD to eliminate crack between different LOD. The view direction and surface coarse are considered in the error metric which is used to decide LOD refinement. We use vertex morphing to smooth LOD translation to reduce the image popping and maintain constant frame rate. An approach of multi-resolution texture mapping is proposed to reduce the texture memory space and selects an appropriate texture resolution based on the terrain geometry LOD. We have efficiently implemented the algorithm and acquire a good tradeoff between image quality and real-time rendering.
Development and Application for 3D Scene Generated System of Driving Simulator ZENG Ji-guo, XIONG Jian, WAN Hua-sen     With the progress of computer software and hardware in recent years, driving simulators are rapidly developed. This paper introduces a system in which three-dimensional scene of driving simulator can be automatically generated. In this system, firstly, road meshes are alternately drew with the road plane design theory. Secondly, system automatically processes the road meshes. Finally, other things, such as tree and house, can be set on the virtual scene, and the scene can be previewed.
Study on Scientific Visualization of Earth Remote Sensing Based on Imagery Simulation WANG Gang, YU Bing-xi     Spectral radiometric and spatial response characteristics of image chains are analyzed, and a scientific visualization method of earth remote sensing process based on imagery simulation is presented. An image chains (IC) model is developed in this paper, and some math models such as pixel-radiance of three dimensional scene acquired by sensor, output signal of detector, random noise and modulation transfer function (MTF) are discussed. Consequently, a remote sensing digital imagery transfer equation involving sensor synthetic response characteristics is derived. Moreover, simulation modules, databases and simulation processes of the professional software RSIS1.0 in the band of visible and near infrared (VNIR) are introduced briefly. Finally, some simulated remote sensing digital images are given.
Research on Visual Simulation System of Autonomous Underwater Vehicle SONG Zhi-ming, KANG Feng-ju, TANG Kai, GAO Li-e, CHU Yan-jun     Based on software platform?/FONT>MultiGen Creator and Vega, the visual simulation system of autonomous underwater vehicle was developed. The software and hardware requirements of the vision node were proposed. The solution to a series of key techniques was discussed; such as the modeling method based on Creator, the effect generation of ocean environment based on modeling and Vega software environment, the development of visual simulation software and the implement of whole system. The simulation results show that this visual simulation system can realistically demonstrate the simulation process of autonomous underwater vehicleand besides, it satisfies the real time requirement of system simulation.
Aircraft Computer Generation Force in a Generic C3I System Test-bed YU Xin, XU Yang, PAN Quan,

ZHANG Hong-cai

    Some concepts of C3I system and the aircraft Computer Generation Force (CGF) in a generic C3I system test-bet are described in this paper. A modern aircraft model with Thrust Vectoring (TV) technique and the post stall (PST) capacity and the control law are given. This approach can deal with non-linear problems. It can simplify the computation processing and lighten computation burden.
Study on Common Simulation System of Land Traffic & Transportation HE Zhen-huan, YANG Zhao-xia, JIANG Xi     The paper brought out the thought of construction of common simulation system of land traffic & transportation and then discussed the construction method from two aspects: construction method of simulation units and structure mode of the system. On the basis of it, the common simulation system of civil traffic and railway could be designed and developed to meet the demand of study of land traffic & transportation.
Scheme Study of Automobile Driving Training Simulator Based on Virtual Reality CAI Zhong-fa, LIU Da-jiang, ZHANG An-yuan     The automobile driving training simulator is a multiple integral driving training instruction system based on general computer which includes automobile driving virtual training, driving examination, and student archive administration. This paper presents a collective structure of the simulator composed of operation simulation subsystem, dynamic simulation subsystem, graphic simulation subsystem, sound simulation subsystem, motion simulation subsystem, operation evaluation subsystem, and data management subsystem. The function, technical principle and schemes of all the subsystem are introduced. And program flow and training contents of the automobile driving training simulator are presented. The application and effect of the driving virtual training are also discussed.
A Shooting-Accuracy-Evaluation-of-Missile Software Developed on MATLAB XIE Li-ping, ZHA Ya-bing     In this paper, a shooting-accuracy-evaluation-of-missile software package (Version1.0) is introduced. This package is based on the Bayes method of tests and is developed on MATLAB version 5.3. We introduce its design, its implement and then the effect of its usage in project practices.
CSLab-A Software for PID Parameters Tuning of Control Systems HU Zhi-qi, WANG Zhi-feng     This paper describes CSLab-software for PID parameters tuning of control systems. Based on Matlab5.3, it adopts several tuning methods for PID controller parameters aiming at single variable control systems. The software provides powerful tools for simulation, analysis and design of control systems, and built up with an open architecture and high extensibility. New tuning method can be updated with small costs. Furthermore, we offer some other complicated control structures so that user can design control system for their needs.
Matlabbased Dynamic Simulation of Aircraft Environmental Control System YANG Feng, YUAN Xiu-gan     According to the working principle, the components' mathematical model of an aircraft environmental system are set up in this paper. Using software Matlab, the simulating modules of components are established. The environmental control system is built including these component modules and the dynamic performance of this system is researched. The predicting and experimental results are in good agreement. This model provides a new approach to simulate the dynamic response of aircraft environmental system. It is helpful for designing and optimizing aircraft environmental control system.
Realization of Dynamic Simulation Software for Strip Laminar Cooling System

CHEN Xiao-yan, CHAI Tian-you,

WANG Xiao-bo, REN De-xiang,

HUA Wen-cheng

    This paper introduces a simulation software package based on the strip laminar flow cooling system of BaoSteel 2050 hot strip mill. The software provides the simulation of strip dynamic moving process after rolling. Visualization and convenient use are the main characteristics of the software. It provides an experiment tool for hot mill staff to design the strip laminar cooling control system and to improve product quality.
Real Time Performance Analysis of ProfiBus Protocol RU Feng, XUE Jun-yi     The real time parameter is a key point of protocol’s performance evaluation. The most important thing is to give an effective and reasonable method to simulation. Based on the analysis of the Data Link level of ProfiBus protocol, this dissertation elaborated a determined stochastic Petri nets model of protocol’s MAC. Aimed at the real-time performance analyzing. Also given a calculation formula combine with the actual example.
Parameter Identification Based on Cascade Extended State Observer ZHANG Rong     The algorithm of parameter identification by extended state observer (ESO) is efficient to the parameter identification problems of the low order systems. However, it is difficult to find satisfying parameters of the extended state observer for the high order systems. Furthermore, the estimation precision of the parameters is not high in only one-time identification. To avoid the above weakness, we combine in this paper the cascade extended state observer (CESO) with the algorithm of successive approximation to reduce the range of the uncertainty of systems with unknown parameters. The estimation precision of CESO is increased with the diminishing uncertainty and the precision of parameter identification is then improved. In the meantime, this method makes parameter adjustment of CESO become much easier than that of the former ESO.
Application of Stochastic Petri Net to System Availability Analysis JIANG Le-tian, XU Guo-zhi, YING Ren-dong, ZHANG Hao     Since presented in 1962, Petri Net is generally focused by academy and industry. In this paper, the application of stochastic Petri net on system availability analysis is mainly discussed. With the beginning of the basic concepts and models of Petri net, stochastic Petri net (SPN), general stochastic Petri net (GSPN) and stochastic reward model (SRN) are illustrated. The application of stochastic Petri net on system availability analysis and analysis of stochastic Petri net model is discussed with the example of standby systems. In the end, the advantages of using stochasticPetri net to model a practical system are discussed comparing to other modeling methods.
Fairness in Bandwidth for TCP Flows in a Differentiated Services Network JIANG Dong-xing, ZHENG Shao-ren     Differentiated Services is a solution scheme for QoS in IP networks. In a differentiated services network, to delivery fairness share of bandwidth to TCP flows is still an issue to be addressed when multiple TCP flows with different flow characterizations respectively coexist within a bandwidth assurance service traffic aggregate. We studied the impact on fairness of different packet length based on the Network Simulator (NS2) and proposed a method to support fairness bandwidth allocation among TCP flows with an implementation of Random Early Detection (RED). Based on network simulation, performance analysis of the method is given.
A Single Warship Passive Location Algorithm Based on Modified Speed XU Jing, WANG Xiu-kun, HU Jia-sheng, ZHAO Jing     A single warship passive location algorithm based on modified speed is presented. Using modified gain extending Kalman filter, this algorithm regards the constraints of moving target warship as additional measures, output of which is zero, and adds it to the measure equation; the constraints intensity is decided by the constraints noise variance. A elusion factor is put forward to constrain the target ship’s speed; the basic idea is to constrain the direction and value of speed with elusion factor when the estimated next period is sailing to land or island according to the present estimated target ship’s position and speed. It avoids the case of target ship sailing to land or island. Computer simulations results show that this algorithm not only avoids the moving track of target ship sailing cross land or island, but also improves the passive location precision of maritime moving target warship emitter.
Design and Modeling of the Ship Shaft Generator Simulator GAO Hai-bo, CHEN Ming-zhao, CHEN Hui     This paper briefly introduces the principles of shaft generator in WMS2000 engine room simulator, the methods of designing and modeling, and some detailed mathematical models. The shaft generator simulator takes SIEMENS shaft generator system as a model generator. According to possibility and training need, the shaft simulator has been simplified to consist of three parts including shaft generator operation panel in central control room, shaft generator rectifier/inverter control panel in engine room and simulation test system in power plant monitoring computer. The following mathematical models are built: energy models, electrical circuit models and control system models. The energy models are built on the grounds of energy balance principle. The electrical circuit models calculate the current, voltage and frequency of shaft generator according to experience formula. The control system models are in accordance with the character curves. The mathematical models can describe the normal and abnormal running processes of the shaft generator system and get a better simulation accuracy under whether stable or dynamic running condition.
Prediction of Big Ship Motion with Wave Survey PENG Xiu-yan, ZHAO Xi-ren, LU Su-ping, WEI Na-xin     The prediction method of the big ship motion posture is discussed, using the wave survey in front of the ship and the survey data of the big ship motion. The Automation Regressive Moving Average (ARMA) model of the ship motion prediction and the Automation Regressive (AR) model of the wave prediction in the front of the ship are introduced in detail. The prediction algorisms for the wave amplitude and the ship motion posture are given. And the longitudinal sway motion of the big ship is simulated. The simulation calculation shows that the prediction precision is satisfied. Finally the ARMA method is compared with the common AR method.
Usage of Bayesian Method in Shooting Accuracy Evaluation of Missiles ZHA Ya-bing, XIE Li-ping     This paper discusses how to make good use of the useful information gained from the results of the simulation experiments so as to accomplish the shooting accuracy evaluation of missiles in case the real experiment sample is small, by using Bayesian method. First the writers introduce chiefly the basic idea of the Bayesian theory. Then the writers put emphasis on how to get the prior information from the results of simulation experiments through the bootstrap method and how to practice the posterior test subsequently. At last the writers show several problems that have to be taken into account while applying Bayesian method to project practices.
Study on Credibility of Physical Effects of Man-in-the-Loop Simulation System ZHANG Wei, WANG Jiang-yun,

WANG Xing-ren

    The credibility of physical effects made by physical instruments in a man-in-the-loop simulation system can directly influence the credibility and application effect of the whole system. In this paper, the factors affecting the credibility of physical effects are analyzed, some essential principles followed in the design of a visual simulation are presented. Then the influences to the visual simulation credibility made by models of geographical environment and the influences to the application effect made by the subjective motion of users are discussed.
Simulation for the Scouting System Searching Objects LI Zeng-lu     This paper analyses the factors that influence the performance of searching system. On the basis of topographic data for the fight field, the paper studies the computation method of vision area when the ground scouting system searches ground objects or low altitude flying objects, and gives the computation method of the stay time of the object in the visual field of optical lens on the basis of the characteristic for the optical lens and the relation between the lens and objects.
Variable Structure Control of the Electro-hydraulic Servo System

HAN Chong-wei, LIN Ting-qi, XIAO Wen-wei, TONG Qing-yu, LIN Zi-qi, ZHU Yuan-hua,

JIA Zhi-yong

    Aiming at the pump-controlled cylinder in electro-hydraulic servo system, this paper designs the switching function using the optimal method and Variable Structure Control (VSC) law using reaching condition, and designs observer to obtain pitching speed. The simulation and experiment results show that the VSC control system based on the optimal method is robust to parameters uncertainties and disturbance, it has been successfully applied in the complex and high performance system, the results demonstrate it better than the conventional PID control.
Simulation for Sheet Metal Flexible Manufacturing System Based on Stocker’s Service Capability SU Chun     Combined with the development of sheet metal Flexible Manufacturing System (FMS), simulation experiments of the sheet metal FMS were carried out. The criterion of stocker’s maximum service capability is proposed. Based on the capability, by means of changing the stocker’s parameters or scheduling rules or the number of machining cells, the basic principle of sheet metal FMS’s design and scheduling is set forth. The results have been preliminarily applied in the development of domestic sheet metal FMS.
Dynamic Counteracting Method for the Centrifugal Force Acting on the Shaker of Vibration Table in the Centrifugal Field LEI Hu-min, TIAN Chang-hui, LIU Wen-jiang, NIU Bao-liang, HAN Yu-hang     In the experiment system of the synthesis environment of vibration and centrifuge, the centrifugal force will act on the shaker of vibration table and force it deviating from the original operation position, which will effect on the normal operation of the shaker. We proposed a dynamic counteracting method by means of the pneumatic spring to counteract on the centrifugal force. In order to realize this method in the experiment system, we designed and established a pneumatic servo system with the computer control. The test results show that the servo system has an excellent performance and can be used in the automatic counteracting system.