Vol 17 Number 5  (2005)

Title

Author

Abstract

Model of Battle  on War Energy XIONG Yan£¬LI Jin-lin£¬TENG Zhong-ping The electromagnetism theories are applied into the battle simulation, and a model of the battle simulation based on the war energy is set up. It can describe the effect of some fighting capacity factors during the troops disposition stage, and can simulate some phenomena hard to be described directly by current models. The model gives out the new method and thought for the battle simulation.
Flight Track Data Creation and Inertial Component Simulation the Strap-down INS ZHAO Hong, ZHAO Zhong, LONG Guo-qing Because we don¡¯t receive easily comprehensive and actual flight track data and inertial component output parameters. But the capability testing of the software and hardware of the Strap-down inertial navigation systems need them. Therefor, the author bring forward the analytical idea of flight track data creation and inertial component simulation. The flight track data and the inertial component that been created by the idea have been applied successfully and gain better effect in system testing.
Fuzzy Modeling for a Nonlinear System JIN Mei, GUAN Xue-zhong, JIN Zhong-shi The modeling method based on fuzzy inference is applied to first-order nonlinear system in this paper, and a mathematical model after modeling is deduced, that is, linear differential equation with variable coefficient. Firstly, according to interpolation mechanism on fuzzy logic system, fuzzy inference rule base is summed up to some interpolation function, then the function is transformed into differential equation with variable coefficient. Thus, a mathematical model is obtained. Simulation results show that the model formed by this method with regard to the real model has higher approaching precision.
Research of Modeling and Simulation on XMSF HE Ming, QIU Hang-ping, LIU Xiao-ming After the HLA, it is the thinking problem in simulation that how the technologies of modeling & simulation (M&S) is going to develop. The 2002 Extensible Modeling and Simulation Framework (XMSF) report [1] goes deep into the problem that Web-based technologies support DoD models and simulations. The framework enables the reusability and interoperability of a new generation of M&S applications to develop. It is described the concept of XMSF, and advantages of XMSF that can be taken to perfect HLA. At last, the suggestions on how to develop the simulation with XMSF are given.
Linear Ocean Wave Simulation NIE Wei-dong, KANG Feng-ju, CHU Yan-jun, YANG Hui-zhen The development of ocean wave theories and several technique used in ocean wave research have been introduced in brief. The linear superposition method and the linear filter method for simulating linear ocean waves have been analyzed in detail. Several algorithms of ocean wave simulation for engineering applications and visual effect have been discussed respectively. Their differences are compared and commented on. Other simulating methods for engineering have also been discussed. Then the limitation of present methods has been summarized. Finally the trend of ocean wave simulation has been indicated.
Global Optimization of Bilevel Nonlinear Programming Problems by Parallel Simulated Annealing LUO Ya-zhong£¬TANG Guo-jin There are great difficulties in solving the general bilevel nonlinear programming problems (BNPP) with the global solutions because of their nonconvexity and indifferentiability. There isn¡¯t an effective global approach for BNPP at the present time, and furthermore, the pleasantly parallel computation property of BNPP isn¡¯t recognized yet. The parallel global approach based on simulated annealing for solving the general BNPP is proposed. A kind of Parallel Simulated Annealing (PSA) combining simulated annealing with simplex method is presented .The higher-level problem is solved by PSA and the accurate penalty function is employed to deal with its constraints. The flexible tolerance simplex method is used to solve the lower-level nonlinear programming problems. The combinational approach makes full use of the pleasantly parallel computation property of BNPP, and the network parallel computations can be easily completed. Its high reliability of global convergence and high convergence rate are testified by the numerical computations.
Application of Modified Nearest Neighbor Method on Case-based Reasoning WEI Chuan-feng, PANG Yu, LI Yun-ze, WANG Jun1, YU Tao Case-based reasoning can deal with those cases that are difficult to describe in exact rules, so it is very important in infer engine, and similarity is usually applied to search the case in it. At present, the nearest neighbor method is broadly adopted, but it has some shortcomings such as aimless searching, much work to calculate and so on. Therefore, a modified method is produced to reasonably decide the case using cluster algorithm, and to find out the mean for each duster. Then, the new case is compared directly with these means to find out the closest duster and the nearest case. Therefore aimless searching is avoided and the algorithm is optimized.
A Method of Computing Basic Firing Data of Ballistic Missiles Based on Disturbance Guidance Law YONG En-mi, TANG Guo-jin It is presented an effective approach for computing the basic firing data of missiles. If the launch position and aiming position are given, the launch orientation and shutoff time can be gotten by iterative method. Then the standard trajectory data is obtained by numerical integral algorithm. And the differential method is applied to compute coefficients of the shutoff equation and guidance equations. Finally the feasibility of this approach is proven by an application to a six-degree flight simulation of one type of missile.
A Modified Genetic Algorithm with Maintaining Diversity SHEN Yuan-xia, ZHANG Cui-fang This paper presents a modified genetic algorithm with maintaining diversity for solving genetic excursion and premature convergence. In the algorithm, entropy of population and locus diversity take as the measure of population diversity of the evolving state. The relation between genetic operation and population diversity is set by their function, which makes the main parameter of genetic operation adaptively adjust according to the varying fitness function and diversity function. The algorithm greatly improves population diversity and the searching efficiency. The experiments show advantages of the algorithm.
Simulation Study of a New Algorithm NDA Based on Fuzzy Mathematical Morphology for White Blood Cell Detection CHENG Ke, WANG Shi-tong, YANG Jing-yu1 White blood cell detection is one of the most basic and key steps in the automatic recognition system of white blood cells in microscopic blood images, whose accuracy and stability greatly affect the operating speed and recognition accuracy of the whole system. Cell segmentation is still an active area of research due to the complexity of the images. It is focused on the approach of white blood cell detection. Based on the detailed analysis for current approaches, a new algorithm NDA based on fuzzy mathematical morphology is proposed for white blood cell detection. Experimental results here demonstrate the very superiority of this new algorithm.
Key Technologies of Numerical Simulation
on Explosion and Impact Effect
 DENG Guo-qiang, ZHOU Zao-sheng, YANG Xiu-min The numerical simulation on explosion and impact effect involves large deformation, high strain rate, and material damage. And traditional computational methods, Lagrangian and Eulerian, are limited in dealing with these problems. Therefore new numerical methods such as remesh, ALE, CEL, SPH, and so on are well developed. In practical explosion and impact engineering analysis, the right rock and soil constitutive law is the key. The high effective parallel computing and scientific visualization are the only way for numerical simulation.
Identification of Hammerstein Model Based on Spline Approximation and Wavelet Decomposition ZHENG Jun, YAN Wen-jun, ZHU Jing A method is presented to approximate the nonlinear gain of Hammerstein model using the cubic B-spline instead of the traditional polynomial approximation. Compared with the polynomial approximation, not only the method is simple and feasible, but also the accuracy of approximation is improved evidently. To improve identification accuracy, we decompose input and output data by applying the wavelet multiresolution analysis because noises are restrained in low-frequency band. The theory analysis and simulation results show that the estimation is asymptotically unbiased and has strong consistency, and that the new method is very efficient and practical.
Parallel Simulation for Spatially Varying Ground MotionLI LI Li-jun, JIN Xian-long On the basis of known knowledge on simulation of spatially varying ground motion, it is focused on efforts to research a parallel method to enlarge the number of spatial points. A code written entirely in FORTRAN 90 and MPI for use on scalable computers is presented, and the precision and velocity ground motion simulation could be improved greatly. The parallel simulation code was embedded into the commercial FEA code by second development, and users could generate ground motion by developed interfaces. The ground motion simulation and seismic analysis for structures could be incorporated a whole process.
Correct Measure Error of Multi-observation Station with Least-squares Method LI Hui1, LIU Zhao, WU Guo-fu ,QI Quan-yue When using optical measurement system network to give the position of a moving aim, people often obtain many measure results because of many interferential factors. Therefore, it reduces the precision of measure. We suppose a new recursive initial value. In order to improve the precision of estimation, the least-squares multi-observation station method is used to determine the position of the observation. We also correct the residual error in order to improve the measure precision. Finally, a simulation example is given to test the feasibility of our method.
Binary-encoding Genetic Algorithms with Modified Mutation Operation LI Liang-min Being a stochastic search technique, there are some shortcomings in standard genetic algorithm such as poor local search ability and premature convergence. An effective method of adapting mutation probabilities on each genome of binary-encoding genetic algorithm is proposed to overcome these shortcomings. At the beginning stage of evolution, larger values of mutation probability are assigned to those genomes in higher bit positions, so that larger feasible region is explored. When the region in which the global optimum exists is found, mutation probabilities of genomes in higher bit positions are decreased to prevent better solutions from disruption. Accordingly, mutation probabilities of genomes in lower bit positions are increased to improve the local search ability. Experiments results on five multimodal functions demonstrate that proposed genetic algorithm possesses better optimization ability and gets stuck at a local optimum fewer times than standard genetic algorithm does.
An Adaptive Ant Colony Algorithm for Vehicle Routing Problem Based on the Evenness of Solution LIU Zhi-shuo, SHEN Jin-sheng Ant Colony Algorithm (ACA) is a novel simulated evolutionary algorithm which shows many promising characters and has been successfully applied to the Traveling Salesman Problem (TSP), which is the prototype of the NP-hard problems. However, ACA has some typical shortages too, such as long computing time, stagnation behavior. ACA is applied to solve Vehicle Routing Problem in terms of the similarity and difference between VRP and TSP, and an Adaptive Ant Colony Algorithm (AACA) is proposed, which is improved from ACA through modifying the pheromone updating rule and the transition rule by introducing Evenness of Solution, Selection Window, Ant Attraction of Arc into it in order to decrease computing time and avoid stagnation behavior of basic ACA. Simulation results show that the AACA can settle the contradictory between convergence speed and stagnation behavior efficiently and is very suitable for solving VRP.
Sensitivity Analysis and Simulation of Performance
for G/M/1 Queuing Systems
 ZHANG Hu, YIN Bao-qun , DAI Gui-ping , XI Hong-sheng We study the problem of the performance sensitivity analysis by the embedded Markov chain for G/M/1 queuing systems. A simulating computation algorithm based on a single sample path of this G/M/1 queuing system is given also. The embedded Markov chain (EMC) is employed here to study the difference between the steady state distribution of the real system and that of the EMC, which is used to correct the result of simulating. Numerical computations of two special G/M/1 queuing systems are given as simulation examples in conclusion.
New Improvement to Jenolek¡¯s Attribute Reduction Algorithm TANG Bin, LI Long-shu, LI Wei, LIU Zheng-yi, YANG Zeng-guang After the analysis of Jenolek¡¯s attribute reduction algorithm and an improved algorithm, it is introduced a new kind of improved attribute reduction algorithm mainly based on storing attribute information in auxiliary space and utilizing some other techniques such as sorting, pretreating a decision table, seeking core attributes and extending an attribute set, which can gain larger reduction in time complexity while having the same performance as Jenolek¡¯s attribute reduction algorithm.
Design and Implementation of Low-cost PC-based Active
and Passive Driving Simulator
 ZENG Ji-guo, ZHANG Yan, ZHAN Shou-yi Low-cost PC-based active and passive driving simulator is an effective facility for training novice driver. It is introduced the hardware structure of this system, the theory of this system and the development of the software subsystems. The vehicle dynamics subsystem developed by object-oriented technology is especially described. This system can simulate many kinds of roads, weather and the complicated traffic situation. In order to train the novice driver to deal with dangerous situation, a danger scene is set in the system. This system is very cheap and useful for training drivers.
The Scheme of A Low Cost Multi-Rotorcraft Cooperated Training Simulator

 GUO Guang-li£¬GAO Zheng£¬SUN Chuan-wei A single rotorcraft training simulator is so expansive and, it is not suit for the large scalar clusters of the rotorcraft simulators. Base on the modern simulation technology, a low cost and high fidelity rotorcraft simulator scheme is talked about in this paper£¬ the kernel model is modeled by the FLIGHTLAB software, and also with a freeware for the visual system, a low cost, high bandwidth network with hierarchy structure for the simulator clusters. This scheme of training simulator clusters is a very efficient and economical device for the modern rotorcraft flight training.
Creditability Validation of Real-time Simulation System SUN Yong-cheng, SUN Ling, JIANG Jin-long, ZHOU Xian-zhong Creditability validation of real-time simulation (RTS) system is an important content of RTS theory research and project application. Firstly, we provide the basic validation procedure of creditability validation, and present the idea that validating the creditability of RTS system, the temporal behavior, logical computation correctness and system stability must be validated. Secondly, we present three indices with their quantitative mode to validate the temporal correctness, then research the relative issues and provide the procedures of logical computation correctness validation, and finally analyze the stability validation of RTS system.
Distributed Simulation of Weld Dynamic Process
Based on RTOS and CORBA
 CHEN Wen-jie ,MA Guo-hong ,CHEN Shan-ben, TANG Yi, LI Wen-hang Dynamic process model of gas tungsten arc welding was firstly established by artificial neural network and then dual variable fuzzy controller was designed. Based on embedded operating system of uC/OS-II, the pulsed gas tungsten arc welding was simulated. When CORBA system on the client gives a signal to the server, the simulation starts. The server transfers the width of weld pool and the current to the client during the process of weld simulation. When there is an error, the client can inform the server to stop weld simulation immediately. It indicates that the weld simulation based on embedded system and CORBA communication can realize the remote control in real-time.
Performance Evaluation Models for Stress and Stretch of Overlay Network Multicast SHEN Bo, ZHANG Hong-ke, LIU Yun It is presented the stress equilibrium model and the stretch eigen-value model for evaluating the performance of overlay network multicast protocols. The stress equilibrium model uses the discrepancy criteria of uniformity measurement to measure the distribution of stress in multicast trees. By looking for the areas where stretch values are dense, the stretch eigen-value model judges optimization degree of multicast paths. Experiments results based on simulations show that the two models can reflect the performance of stress and stretch well for multicast protocols with overlay network.
Theoretical Analysis of GALT Algorithm TANG Jing-qiao£¬HOU Chao-zhen GALT (Greatest Available Logical Time) algorithm is the key technology which decides whether time management service in the interface specification of HLA (High Level Architecture) can be realized. Unreasonable GALT algorithm will result in deadlock or destroy the rules of time management of HLA, which will make the whole federation unable to advance, or generate messages that should occur before. The deadlock problem of the Frederick algorithm and the stature measurement algorithm is analyzed, and a sufficient condition of deadlock made by the Frederick algorithm is given. The condition that they obey the time management rules are discussed especially. A suitable GALT algorithm can solve the deadlock problem ultimately until it guarantees that it obeys the rules of time management£®
Jitter-dependent Optimal Bandwidth Scheduling for CAN-Based Networked Control Systems (NCSs) BAI Tao, WU Zhi-ming, YANG Gen-ke The key issue of analysis and design of the NCSs is to assign the limited bandwidth resource properly so that the network influence on the controlled plants is as little as possible and the real-time requirement and the control performance requirement are both satisfied. Jitter-dependent optimal bandwidth scheduling algorithm for CAN-based NCSs is proposed. It finds the optimal sampling period and the optimal initial phase for each control loop under both constraints of control performance and network schedulability such that the bandwidth resource is allocated properly and utilized efficiently within the acceptable range of jitter for the dynamic performance.
Network Data Delivery Service Based on RTPS Protocol LIN Xiao-hui, LI Shi, LIN Jian It is described the Network Data Delivery Service Based on Real-time Publish/Subscribe protocol, the means of data transferring by NDDS, the features and the application range of NDDS. Especially because of the special properties and functions of NDDS, it has more ability than any other network data delivery software: it can be used in data delivery in real-time system, and it can also be used in distributed real-time simulation system after customizing development.
A Novel Modeling Method for Analysis of IP Networks JIA Guo-jun , DAI Lian-kui A novel modeling method is proposed to analyze actual IP networks. This method decomposes an IP network into several basic units and constructs the mathematical model of the network by setting up the corresponding state equation for every unit. Based on the Bohacek¡¯s model, we develop a first-order differential equation to describe queue change in an output port of a router, which reduces system complexity obviously without sacrificing simulation precision. The RED-marking strategy is introduced for the queue management of routers. Finally, we build a mathematical model for a simplified network. The model is well validated by comparing its analytical results with the NS simulation results.
Mesh Deformation and Generation to Realize the Graphics Display of Cut Tooth in Haptic Display System LIU Guan-yang, ZHANG Yu-ru, WANG Dang-xiao It is introduced the graphics display of cut tooth by mesh deformation and generation in the virtual environment of haptic display system. In virtual environment the tooth and the tool are constructed by triangle-mesh. When operator use tool to cut the tooth, the vertices of tooth mesh which are surrounded by the tool will move to the surface of the tool, and all strait triangles generated in the course of mesh deformation will be fractionized to two or three triangles. By deforming and fractionizing the mesh of tooth, the graphics display of the course of tooth£­cutting will be realized factually with no delay.
System of Virtual Maintenance Prototype and Modeling Technology WANG Song-shan, HAO Jian-ping It is investigated the problem of how to build a virtual prototype (VP) used for virtual maintenance simulation, which is called virtual maintenance prototype (VMP). After analyzing of the definition and components of VMP, the system structure of VMP that is linked to the CAD system of product is given. In order to support real time virtual maintenance simulation, a maintenance-task-oriented VMP modeling is addressed to represent geometry modeling and human-object interaction modeling. And the processing of CAD data and interaction behavior modeling focused are developed in Jack, which is illustrated by a gear-box¡¯s virtual maintenance simulation.
Project Management in Virtual Prototype of Complex System ZHU Yao-qin, WU Hui-zhong, YU Yong-jia In terms of shortened product life cycles and increased product complexity, more and more people began to use the virtual prototype, instead of the physical prototype, for innovation, test and evaluation of product design. So the research on virtual prototype has been a hotspot for several years, the development of relative basic techniques is also rapid, and there have been successful application cases in foreign countries. However, the research on collaborative virtual prototype of complex system is still in the juvenile stage. The lack of information management in entire lifecycle, all round and total system is one of the obstacles. Based on the definition of virtual prototype and complex system, it is analyzed the demands on information management of virtual prototype of complex system. Several key techniques in project management of virtual prototype of complex system are discussed, and the integration of project management with other modules (for example, workflow management module) is also probed into. Above these, it is presented project management system of virtual prototype of complex system and the application about it. In the end, summaries are given.
Study on Human-Computer Interaction Technology in Certain Virtual Operating Training System LIU Peng-yuan, LI Rui-hua, ZHANG Xi¡¯en It is firstly introduced the development status of human-computer interaction technology, and then the procedure simulation model of certain weapon system virtual operating training system is given. The function of human-computer interaction system in the procedure simulation model is explained. Based on introduction of the function of human-computer interaction system, emphasis is laid on introducing the procedure and methods of direct manipulation with such virtual equipments as 3D tracking system and data glove, and in the end the virtual operating training system of certain weapon system is accomplished with adoption of the direct manipulation technology.
Direct3D-based Dynamic Terrain Realization in Virtual War Environment ZHANG Xiao-chao, WANG Jing-ye, LIANG Qiang Dynamic Terrain technology breaks through the destructible restriction of the traditional terrain surface. It can exhibit the change of the terrain structure that caused by internal force of environment or by the behavior of simulation entities, thus shortening the distance between simulation and the reality. It is focused on the study of Triangulated Irregular Network-TIN, and a TIN managing method via building a Reference Network is introduced. It is analyzed the storage format of Terrain Database in Direct3D environment, articulating the searching method to locate the projection position in Terrain networks of any ground surface point. Based above, changing terrain surface appearance can be realized via modifying terrain database that stored in memory.
The Integration of Geographic Information System and Combat Simulation XU Bing-li, GONG Jian-hua, LIN Hui , HUANG Jun-qing, ZHEN Chang-wei After analyzing the similar characters between Geographic Information Systems £¨GIS£©and Combat Simulation(CS) and GIS-effects on CS, this paper brings forward three integrations of GIS and CS©¤©¤self-help integration, embedded integration and seamless integration. This paper also designs three frameworks which match three integrations, addresses their advantages and disadvantages, discuses some key technologies, and gives prospects of the integration of GIS and CS.
Key Techniques and Generation in Virtual Battlefield Environment LI Min, SUN Ji-yin Virtual battle environment is an important visible platform for military simulation. Based on the implementation of a specific military project, the system components were described. The key techniques of virtual battlefield environment creation applying VR were analyzed and discussed, including a fast algorithm for 3D-modeling based on complexity, the techniques of 3D-terrain generation and simplication, virtual roaming, multiple views and human-computer interaction etc. The feasibility and utility of the methods presented have been demonstrated satisfactorily by two large-scale net-war-simulations.
VR Flier£ºA Software Platform for Virtual Reality General Application Development PI Xing-zhong, FAN Xiu-min, YAN Jun-qi A software platform named VR Flier which is oriented to virtual reality (VR) general applications development is presented. It is finished based on some software tool libraries from the market or developed by ourselves. VR Flier is cross-platform, modular and extensible. It can support successfully all kinds and all sizes of VR application development. The concept model, architecture, interaction processing, main process, and development process of VR Flier are introduced in detail. Finally, a case for structure design of composite material component developed by VR Flier is presented.
Design and Implementation of Bicycle Simulator GAO Xin, SUN Han-xu, JIA Qing-xuan, SONG Jing-zhou, ZHAO Feng It is presented the design and implementation of VR-BWS bicycle simulator. The VR-BWS takes the bicycle as the carrier of human-computer interaction, and integrates sensor technology, DSP control technique, three-dimensional modeling£¬collision detection and multimodal interactive technologies such as stereo displaying. The feeling that a participator experiences in virtual environment is just like that in real one.
Research on Construction and Real-time Rendering of Virtual Environment Combining Image-based and Model-based Method CUI Han-guo, ZHANG Xing, LIU Xiao-cheng The kernel and foundation of virtual reality is the construction of virtual environment and to handle the environment friendly. There are two methods to implement a PC-based virtual environment: the image-based method (IBM) and the model-based method (MBM). Both of them have their advantages and disadvantages: although IBM has good realistic and good real-time capability, a virtual environment built by IBM can not be manipulated. MBM method supports real-time manipulation, however, it faces some difficulties such as realistic, etc. Taking the advantages of IBM and MBM, a virtual environment construction and real-time graphics generation system that supports photographs and geometric modeling is developed on microcomputer. The structure, functions, typical examples and some key technical details of the system are presented.
Simulation Research on Doppler Compensation
for Underwater Acoustic Communications
 ZHANG Xiang In underwater acoustic communication, carrier tracking and symbol synchronization are adversely affected by Doppler, which is caused by the move between the transmitter and the receiver. So the Doppler compensation is one of the key techniques for acoustic communications and becomes more and more important. It is presented a new Doppler estimation and compensation scheme, which is suitable for underwater acoustic communications between rapidly moving platforms. Some questions relative to the Doppler shift compensation, such as the ambiguity function method, choice of signals inserted in the data packet, sampling-rate conversion, determining the number of subfilters (or interpolating factors) and interpolation are studied. This method is verified and its performance is analyzed by simulation.
Performance Evaluation of ATR Based on Fuzzy Integration LI Yan-peng, LI Xiang, ZHUANG Zhao-wen Aiming at performance evaluation of Automatic Target Recognition (ATR), a general idea is developed; the evaluation indices and their measurement method are chosen; the information being referred is presented. Then, a performance evaluation model is formed based on fuzzy integration. In the end, simulation is carried out by test data and synthesis data.
Face Recognition: An Approach Based on Feature Fusion and Neural Network YU Dong-jun, ZHAO Hai-tao, YANG Jing-yu A complete face recognition system based on feature fusion and neural network is proposed in this paper. The new face coding technology based on the fusion of SOM and Shape features is utilized. The dimensionality of the fused feature space is reduced using generalized K-L transform. The corresponding reduced feature is then processed by the Uncorrelated Discriminant Transform (UDT), which has better classification capability than that of the classical Foley-Sammon Discriminant Transform (FSDT), to obtain optimal discriminant feature. Finally, a Multi-Layer Perceptron (MLP), the output of which consists of class membership values, is utilized as the face recognizer. Experimental results on the face database NUST603 of 960 face images corresponding to 96 subjects show the effectiveness and robustness of the proposed approach.
Gaussian Kernel Density Estimation-based Background
Modeling with Noise and Shadow Suppression
 MAO Yan-fen, SHI Peng-fei A multimodal nonparametric background model is proposed to detect moving objects by background subtraction. In outdoor surveillance systems, the solution to some of the problems such as illumination changes, initialization of model with moving objects, and shadows are provided. The Gaussian kernel density estimation is exploited to estimate the probability density function of background intensity and to initially classify each pixel as belonging to background or candidate foreground. Pixel¡¯s neighbor information is considered to remove noise due to camera jitter and small motion in the scene. The Hue-Max-Min-Diff (HMMD) color information is used to detect and suppress moving cast shadows. That decreases the false positive in object detection. Experimental results demonstrate the robustness to noise and shadow and good detection performance, and it can be used in outdoor environment surveillance systems.
Research on Neural Network PID Control with Application to Heavy-duty Wheeled Vehicle Steering System YUAN Hai-bin, Li Yun-hua, YUAN Hai-wen, YANG Li-man According to the plant characteristics and the operating method of the heavy-duty wheeled vehicle, a neural network controller is proposed for improving the control performance of the traditional PID controller. The configuration of the control system is based on RBF neural networks, one is RBF neural network identifier (RBFNNI) used to identify the Jacobian matrix of control plant, and the other is neural network controller (NNC) used to provide nonlinear PID control parameters, which is used to achieve the better performance than conventional single PID controller. Then, neural network architecture is designed according to improved control algorithm. At last, simulation result is given and discussed. The result shows that the control system is robust and adaptive in dealing with nonlinear systems, so it is feasible for control steering and manipulating system of the wheeled vehicle.
Real-time and Visual Simulation System Design for Guided Bomb SANG Bao-hua, XUE Xiao-zhong, BAI Jing, SUN Rui-sheng By using OpenGL library, a perfect design interface of three-dimension graphics application program can be set up. Meanwhile, OpenGL¡¯s virtual reality technology can also be applied in the real-time simulation of bomb-dropping experiments. A method of how to employ OpenGL ,Visual C++ 6.0 and serial communication to develop a visual and Real-time simulation system for guided bombs is introduced. It is also explored the signification and functions of the system, in which the flying postures and all kinds of functional parameters can be displayed real-timely and visually. As it has been proven by experiments that this system can completely gain its ends in real-time simulation.
Distributed Flight Control System Implementation Based on Event Service WANG Hui, XU Jin-fa According to the flight control characteristics for unmanned helicopter, we design distributed flight control system by means of using middleware TAO and its event service mechanism. To implement this system, common event service components are developed, other components that need event service invoke them simply and communicate with other components that may lie on different computers, different operating systems or may be written in different languages. The simulation demonstrates that this mode of implementation could enhance reusability and reliability of system components, decouple components, enable system to be designed effectively and reduce the development costs.
Food¨CChain Algorithm and Application to Supply¨Cchain Planning YU Hai-fei, WANG Ding-wei Emergence and dynamic interaction with the environment are the two vital characteristics of artificial life, that is, the micro-interaction with each other in the artificial life¡¯s group may result in emergent colonization in the whole system. And food chain appears to be an important and widespread phenomenon in the living system. Based on the above ideas, we propose a new type of artificial life-based algorithm. It is referred to as food chain Algorithm. Then the algorithm is applied to solve the supply chain planning problems of partner selection and their product capacity in the enterprise alliance. How the enterprise alliance select its partners to form enterprise alliance and how member enterprises adjust their product capacity to meet the future market demands can be simulated by the food chain algorithm. The algorithm effectively figures out the above problems with distributed characters. Furthermore the algorithm can be applied to other problems of supply chain management like the location allocation problem.
Situation Assessment Model of Complex System and Its Implementation Method Based on Ontology WEI Shou-zhi, ZHAO Hai, WANG Gang, ZHANG Xiao-dan In order to solve effectively the issue of online situation assessment to complex system, a kind of new intelligent assessment model of network on-line is proposed based on information fusion theories on network environment. The integrated project combined qualitative and quantitative assessment strategy with local and synthetic strategy. First of all, qualitative assessment is performed. In case system is abnormal, the integrated neural networks group will perform immediately quantitative analysis and classification to multi-sources character information from multi-sensors. At last, two level D-S evidence reasoning model will assess synthetically to outputs of ANNs and local D-S models in their fusion center respectively, and the precision and reliability of assessment conclusion are improved evidently. The model has been implemented based on ontology and had been tested and run in Fengman Hydroelectricity Digital Simulation System that we developed. The implementation shows that the proposed model is effective and has practical application value.
Scenario Generation and Management of HLA-Compliant Underwater Engagement Simulation YAN Jin-tun, KANG Feng-ju, SU Ying The architecture of Scenario Generation & Federation Management (SG&FM) software system in HLA-compliant underwater engagement simulation is set up, by adopting modular and layered design method. Based on the analysis of the campaign military conception model, an underwater engagement simulation conception model is developed. Design methods of scenario database and scenario entity parameter models are presented. Such technical problems as federation management and control, situation awareness display and information processing of dynamic entities are solved. Based on all above work, SG&FM software is designed and developed.
An Algorithm of Weak Object Detection Based on Composite RBF Network and Chaotic Theory PAN Xiu-qin, ZHANG Chun-hua, HUANG Hai-ning, ZHANG Hong Aiming at the problem of weak object detection with complex background, a detection algorithm based on composite RBF network and chaotic theory is presented in this paper. the simple strcture is owned by the algorithm. The analysis of realibility and reasonablity of the algorithm is given, and the detection algorithm, combined with the established nonlinear predicting model based on predition error optimum combined as well as the seleted threshold, is realized. On the fundation of theory study, the simulation on the given algorithm is carried out, and the results illustrated that the algorithm is valid.
Health Evaluation and Monitoring of Complex System Based on Biological Immune Mechanism ZHANG Xiao-yang, SUN Yu Simulation and implement of biological immune mechanism are very valuable to the condition monitoring of complex system. It is analyzed the immune process and its characteristics, and put forward a simulated architecture of immune mechanism basing on multi-agent. It is also set up the logic structure model of immune agent that simulates the biological immune mechanism to monitor, diagnose and learn the faults. On the basis of which an application regarding a real FMS (Flexible Manufacturing System) as background is studied, the methods of faults recognition and evaluation are proposed which can be used to coordinate and control the FMS. The simulation experiment indicates that this method is effective and feasible.
Negotiation Method to Resolve Conflict of Shared Resource in Troops Cooperation XU Run-ping, WANG Shu-zong, GU Jian Negotiation is the basic means resolving the limited resources conflict of MAS. On the basis of the negotiation theory and method, and on the confrontment¡¯s background between the red¡¯s ships formation and the blue¡¯s ships formation at sea, the system shared resources are firstly divided into two sorts: the repeating resources and the consumptive resources. Then, the two sorts of dispelling the resources conflict models are established, the model selection rules are provided, and the run flows of the basic interchanging negotiation processes are described.
Simulation Research on Jamming to Radar Altimeter AN Hong The basic methods of electronic jamming to radar altimeter are introduced, and the mathematical models of ground echo power, ground jamming power and bounce jamming power received by radar altimeter are provided. Some experiment results are discussed to illuminate the relation between the parameters of jammer and the jamming effectiveness. The optimum design parameters and the applicable methods of radar altimeter jammer are provided to supply references to the designer or the user of radar altimeter jammer.
Simulation Research on Vertical Emergency Evacuation System in High-rise Buildings ZHANG Peng, ZHU Chang-ming, YANG Guang-quan