Volume18  Number 2  (2006)

Title Author   Abstract
Modeling and Simulation of Navigation Calculating Subsystem of Launch Vehicle LI Hui, WANG Bo, HAO Xing-wei Adapting the CZ series Launch Vehicle as research object, and focusing on the mathematical model of navigation calculating subsystem of Launch Vehicle, the simulation model of the subsystem was established in MATLAB/Simulink. The subsystem was divided into a series of independent functional units, such as earth gravity acceleration calculating unit, velocity calculating unit, displacement calculating unit etc. The sub simulation models of these units were built in Matlab/Simulink. The model of navigation calculating subsystem of Launch Vehicle was acquired by means of integration. Comparing with the real sampling data, the results show that the model is sound and the method is validity.
A Method of Petri Net Synthesis and Its Application in System Modeling XIA Chuan-liang  A scheme was obtained using synthesis of Petri nets sharing a kind of subnet, according to process of several enterprises sharing a plant to produce some product. First, the Petri net model of single enterprise in sharing a plant to produce some product was set up. Second, the global Petri net model was obtained through using shared subnet synthesis method. Using the global Petri net model can actualize synchronization and save resources. Several conditions were proposed that the synthesis net of free choice nets (FC){asymmetric choice nets (AC)} is a FC net{AC net}. Some conditions of the structural liveness preservation by the shared subnet synthesis of Petri nets were obtained. These results are useful for studying the properties of Petri synthesis nets and establishing models for large complex system and practical to use in reality.

Simulation of Global Optimal Flight Path Planning for UAV

QU Yao-hong, PAN Quan, YAN Jian-guo, XIAO Gang, ZHANG Hong-cai

Based on the artificial potential field and genetic algorithms, a method of flight path planning for UAV in the threat network was proposed. The threats were divided by Delaunay triangulation. According to the passing directions and sequence of the triangles’ lines, a binary coding method was designed. Then the threats were taken as repulsion sources and the steady-state result of the differential equations is the optimal flight path of the code array. The global optimal flight path could be obtained by using genetic algorithms. Simulation results show that the method is effective.
Agent-based G net and Its Use in Modeling FAS LIU Wei-lai, LIU Zhi-gang, ZHANG Ping, WANG Jian-ping, KONG Fan-rang Based on the theory and methods about agent, knowledge place and plan place were introduced to enhance the G-net and form a new model named agent-based G-net (AGN). The steps and methods of how to use the AGN to model an FAS were studied. The model of FAS constructed with AGN has many advantages, such as clear construction, integrating Petri-net and agent, easily enlarging the model and programming in distributed manners, and the model is more intelligentized and modularized.
Simulation Research of Semi-Active Suspension System of Tracked Vehicles Based on Multi-Body Dynamics Theory YIN Zhong-jun, CHEN Bing, GU Liang, HUANG Hua  Optimal Damping Ratio (OPR) of a suspension system was existed and proved by linear vibration model on suspension system of multi-wheel vehicle. The theory of semi-active suspension was established by the OPR control policy of statistic meaning. Simulation of suspension dynamics of a full tracked vehicle was researched using visual mechanics method based on multi-body dynamics theory with the co-simulation technology of mechanical system and control system. Dynamics characteristic comparison of the tracked vehicle equipped with passive and semi-active suspension was done by the co-simulation method. Finally, a conclusion is drawn from the simulation results that ride-comfort of tracked vehicles can be improved and vibration acceleration can be decreased obviously if the OPR control semi-active suspension is used.
Hierarchical Modeling Analysis Method Based on UML and Petri Net JIANG Jin-long, ZHOU Xian-zhong, SUN Yong-cheng, XU Yan-yong3 The modeling analysis mehtod with new manner combining UML with Petri Net.was proposed. This approach adopted a hierarchical analytical method with top-down techniques, described the whole systemic structure and static property through extended UML model, showed systemic dynamic characteristic using extended Petri Net then transformed to the corresponding State Diagram and Sequence Diagram, finally integrated all UML model and realized systemic code through RationalRose or other software. At last, the approach was illustrated by its application to FMS.
Research of Modeling and Simulation for PMS Reliability CHEN Yu-bo, YU Yong-li, FENG Hui-juan, QU Chang-zheng, Nie Cheng-long PMS is a typical kind of complex system, which consists of consecutive and non-overlapping time periods phases, it is difficult to evaluate its system reliability although it has been studied for more than 20 years abroad. The model of reliability for PMS is discussed and analyzed. At last, a new model in evaluation of reliability for PMS is carried out based on system efficiency, then large amounts of simulation computing is executed and the simulation results are thoroughly analyzed.

Engineering Simulation Method of Variable Wind Field in Synthetic Natural Environment

LIU Gang, WANG Xing-ren, JIA Rong-zhen Synthetic natural environment (SNE) includes four primary domains: terrain, ocean, air and space. As an important part of air environment, variable wind field would affect the performance of aircraft. Considering the two main representations of variable wind field, the engineering simulation method of wind shear and atmospheric turbulence were established. With a simulation example of a certain missile, the effect of variable wind field to the attitude and track characters of the missile was analyzed. The results show that the model established is valid and practicable for engineering.
Reconstruction and Simulation of 3D Human Model in Weight Lifting Sports LIU Guo-yi, CHEN Rui, DENG Yu, LI Hua A new approach to reconstruct 3D motion of body in multiple-camera environments is presented. Comparing to traditional motion capture techniques, the “marker-free” method is easy to use and need cheaper equipments. The video-based 3D body tracking method under the non-linear optimization framework was proposed, which combined multiple cues and motion prior efficiently. By defining the body model, projection process and similarity function, the tracking object function was defined. A method based on shape matching was also promoted to solve the occlusion and error accumulation problem. The experiment of reconstructing the weight lifting motion indicates this method can be used for sport reconstruction and improve athletes’ performance by analyzing the reconstruction result.

Real-time RK4 Formula with Maximum Stability Region

 JIANG Min, HUANG Zhen-quan, WANG Jing Real-time simulation often requires a computer to interact with external hardware in a dynamic loop. Data must be sampled from input signals and incorporated into the numerical integration algorithm to calculate the state variables. Also, data from the integration process must be outputted in time. Thus, the ability for choosing a larger integration step-size is often demanded, so as to guarantee enough time for computation. The problem concerned with the stability region of real-time fourth-order Runge-Kutta formulae is converted into the one of restricted optimization for maximum, and the condition for maximum stability region of real-time fourth-order Runge-Kutta formulae is found. Also, based on the relation of local truncation error and related coefficients, a problem of restricted optimization for minimum is gotten, and a new real-time RK4 formula is deduced finally. The formula has not only maximum stability region, but also the function value of local truncation error which is smaller than the other known real-time RK4 formulae. The simulation results show that the proposed formula is feasible and effective.
Simulation System of Plane Low Altitude Penetration Route PlanningBased on PC YE Wen, MA Deng-wu, TAO Yong-hua The integrated low altitude penetration route planning simulation system was construced based on PC Windows 2000 operating system by the mixed programming for Visual C++, OpenGL and Matlab, and the software program technique was discussed. At last, a simulation example was given whose results show that the simulation system works perfectly well.

Yaw Predictive Model of Unmanned Helicopter Using Elman Network

 ZHANG Ya-ou, LV Tian-sheng, DU Jian-fu The dynamic model of yaw movement of the unmanned micro helicopter was developed. Experiments with an on-board measurement system were set up to gather the data of the flying helicopter. The experiment data were used to identify the yaw control dynamics predictive model of the unmanned micro helicopter firstly with Elman neural network. The Elman dynamics model was contrasted with several other methods. The advantage and feasibility of the predictive model were validated by the experimental simulation.

Modeling and Simulation Research on Electrodynamic Vibration Generators

FAN Xuan-hua, HU Shao-quan Finite element modeling was carried out on a certain electrodynamic vibration generator itself. Methods of modeling were introduced. Then the modal was updated and its mode of vibration was analyzed according to the modal test data of the vibration generator. The results show that the finite element modal of the vibration generator embodies its actual dynamic properties that can be used for vibration test simulation. Finally, according to the real conditions of sine-scan vibration test, simulation was accomplished by using the given algorithm.
Modelling and Simulation of Interior Trajectory Model for Torpedo Swim-out Launching WANG Yan-fei, ZHANG Zhen-shan, ZHANG Meng Based on the analysis of forces acting on torpedo under abnormal limitation boundary condition in the swim-out torpedo tube, the interior trajectory mathematical model for torpedo swim-out launching was set up. The testing method was used to describe the push force of airscrew. The concept of control body was introduced to calculate the flow losses according to the different movement phase of torpedo in the variable section tube. The computer simulation was made. Compared with testing data, the creditability of the interior trajectory mathematical model was proved.

Research on Grey-Scale Image Based Extraction Fingerprint Minutiae Algorithm

ZHAO Ying-ding, DAI Shi-ming，LIU Jin-gang A new algorithm for direct extract fingerprint minutiae from grey-scale image was proposed. Different from traditional fingerprint minutiae extraction algorithm, this algorithm does not need thinning and filtering which demands complicated calculations. First, fingerprint images underwent normalization operation, then an unprocessed ridge closest to the center of the fingerprint image was located, next, candidate minutia was found along the ridge, after that, true and false minutiae were judged according to the given judgment conditions. Finally, all the pixels were marked along the ridge. Other ridges will be processed with the same method. It is confirmed through algorithm implement that this algorithm is apparently faster than traditional ones.
Digital Watermarking Algorithm Based on Wavelet Transform Tree Structure of Image

WU Fang, RUI-Guo-sheng

 An adaptive watermarking algorithm was given based on wavelet transform and image-content. The algorithm used the tree structure of the coefficients of the wavelet transform of the image and the characteristic of coefficients of all layers to classify the important coefficients of the lowest frequency. According to different groups, the watermark was embed in different ways through the human visual system. Moreover no host image was needed in watermarking extraction, which was a blind watermarking algorithm. Experimental results show that the method is simple and effective with high capacity of watermark. It has better imperceptibility than the former one, PSNR=52.28dB.And it is robust against normal image processing and kinds of attacks, for example JPEG compression, filtering, adding noise, rotating and zooming.
Research on Design and Application of HLA Simulation Result Database JU Ru-sheng, QIAO Hai-quan, QIU Xiao-gang, HUANG Ke-di The importance of simulation result database in HLA based simulation is explained. A method towards the collection and recording of simulation data is put forward. The principle and technique of creating tables were analyzed based on Object Model Template (OMT). Besides, based on a representative example, the detailed process of creating tables was described using simple type data and complex type data. Towards the problem of data integral recovery in HLA, two different measures were brought forward. One is to recover data in preserved memory; the other is to recover data via databases. In addition, the strategies of loading huge amount of data and the management of indexes are presented. Finally, towards the data in database, two preliminary process algorithms of abnormal value elimination and smoothly data process were introduced together with the application of COGNOS business intelligence software.
Design and Realization of Battle-field Environment Database for CGF DONG Zhi-ming, GUO Qi-sheng, WANG Hui  Traditional visual simulation database can’t supply requirement of Computer Generated Force (CGF) for environment data. The Battle-field Environment Database (BEDB) for CGF is imminently requisite. The layer model of integrating grid with vector method was established. The area of unpass search arithmetic was proposed based on physiognomy for the tank path planning and the right of direct arithmetic. And the Battle-field Environment Database Editor was not only developed, but the BEDB’s APIs for CGF was also compiled. The CGF simulation results show that real-time and practicality is enhancive rapidly.

Using Simulink Model in HLA Simulation

QIAO Hai-quan, TIAN Xin-hua HUANG Ke-di Several implementation of reusing MATLAB models in HLA simulation was described, and their advantage and disadvantage were analyzed, and then a new method using Simulink models in HLA simulation was proposed, that is adding the RTI interface blocks to Simulink model. Simulink model could communicate with RTI via the interface blocks. After the model was tested successfully, it could also generate C++ code using Real-Time Workshop, and this made the model run more effective. Then the development technology of RTI interface blocks was described, which included S-Function, data type mapping and data pack/unpack, code generation, RTI interface block auto generation, etc. At last, the run-time efficiency of federate program that was developed using RTI interface blocks was given through comparisons and analyses.

Design and Realization of Train Operation Control SystemOnboard MMI Based on UML

　

WANG Xi, TANG Tao The design of GUI is an important part in the software system developing. Based on the characteristic and function of Train Operation Control System, a GUI model was introduced. UML and Rational Rose tools were applied to the requirement analysis, general design and detailed design. Different views were built up to explore the static and dynamic models. The function requirement and function flow，instructions and relations of classes，alternation and communication between objects were described as well. By this way, the quality and efficiency of software design were improved. Finally，the onboard Man-Machine interface (MMI) was accomplished using object oriented program language. 
Study on Video Simulator of High Resolution Synthetic Aperture Radar WU Shu-quan, JIANG Fa-yu, LI Tao According to the application request of high resolution SAR and after analyzing the localization of some simulator the design of high resolution SAR based on embedded system was introduced. The rate can be up to Gb/s through selecting the apt device. With the steady and reliable result of application, the design of easy-to-use controller is a good reference for other high rate design.
Design of Efficiency Assessment Simulation System Based on HLA for Electronic Jamming against Space-borne SAR JIAO Xun, CHEN Yong-guang, LI Xiu-he  The efficiency assessment simulation system based on HLA for electronic jamming against space-born SAR is one part of the systems in space electronic reconnaissance and countermeasure. The aim of the system is to build a simulation environment for the space radar imaging reconnaissance countermeasure, evaluate the jamming efficiency, validate its effect, and investigate the space offensive defensive tactics and techniques. Therefore, SOMs were designed in detail.

Hardware in-the-loop Simulation of Celestial Navigation System

QUAN Wei，FANG Jian-cheng Because of high spaceflight laboratory fees，it is impractical to take star-pictures real time in order to debug star sensor and test the algorithm of star map identification. In order to test the performance of identification algorithm, shorten the development cycle of star sensor，as well as reduce the cost and improve the efficiency of development, a new type of hybrid simulation system for celestial navigation was proposed. The configurations、functions and features of the system were ntroduced. The implementation methods and the specifications of the system were described, which had the feature of flexibility and expansibility. At last，by using the hybrid simulation system，some algorithms of star map identification and performance of star sensor could be effectively verified by dynamical and statical test in this platform. The test results show that this system meets the specified performance index.
Application of KQML Agent Language in Communication Mechanism of Tank Unit CGF LI Yong-qiang, XU Ke-hu, CHEN Jian-feng, HAN Zhi-jun The study of communication mechanism of tank unit CGF is the main topic, and it’s also the difficult problem in current study. advantage of Agent modeling and simulation was made full use of to first bringup the realization of mutual correspondence and communication deliver among tank unit CGF with Agent KGML, and build up a model of communication mechanism among tank-agent. The rationality of communication mechanism of tank unit CGF was tested and a reasonable conclusion was made. At last, thiswill offer good reference in building valid dependable and transparent communication mechanism in development of tank unit CGF.

Multiple Mobile Targets Capturing Algorithm Based on Dynamic Role

LI Shu-qin, WANG Huan, LI Wei1, YANG Jing-yu

Based on dynamic role assignment, a new method for forming coordination multi-robot teams in the multiple mobile targets capturing was proposed. In this method, each robot in the team performs a single role. Because of the role’s dynamically assuming and exchanging along with the change of environment, and a dynamical team forming is realized, thus no only can the team adapt the unexpected events coming from the environment but also each robot can improve its individual performance in benefit of the team also. Test result in the simple environment shows that the intelligent mobile target can be captured more efficiently and the methods proposed in this paper is effective.
Prediction-based DiffServ Model and Simulating Analysis ZHAO Qi-gang, LI Qun-zhan, PENG Hu The chaos related theories were taken use of to analyze the real network traffic about its chaos properties and prediction attributes. According to the good performance of chaos-based prediction in short term forecasting, the prediction-based DiffServ framework and the Dynamic QoS scheme were firstly given. The OPNET-based simulating result shows that the QoS performaces and the network’s throughputs in heavy-load environment are all improved remarkably, comparing with the traditional static QoS configuring and measure-based dynamic QoS setting methods.
Socket Migration in Distributed Simulation System LIU Yun-sheng, ZHANG Chuan-fu, ZHANG Tong, ZHA Ya-bing, HUANG Ke-di In the process migration of distributed simulation system, except saving and restoring the state of processes, it is also critical to save and restore the state of network communication between the simulation processes. The network communication states mainly consist of two parts, that is, the IP address and interactive data. Socket migration in user space was realized by intercepting and revising corresponding system calls. In  the method, heartbeat mechanism monitors the connection error. Further, the system calls was revised, which could store the IP addresses and interactive data in checkpoint files. Based on the saved information, the recovery of communication relationship between federates and RTI was realized. The test result shows that the system can successfully achieve the migration of the socket communication relationship.

Analysis of Some Key Problems in Aggregated Force Simulation

YANG Li-gong, GUO Qi-sheng With the constant expansion of the distributed interactive simulation systems scale and the demand of VV&A, aggregated force simulation is getting more and more important. The aggregated force is just a relative concept in nature and it should be restricted in application. The characteristic of aggregated force simulation and some concepts such as aggregation, combination, discerption, disaggregation and so on were analyzed. Three methods of selecting models on multi-resolution modeling were introduced, and their advantages and disadvantages were analyzed, especially the shortage of Multiple Representation Modeling method that is in wide use abroad. Finally, some problems with aggregated force simulation were pointed out and the future from the perspectives of battlefield representation, combat model, command and control processes and maintain processes was prospected.
Design and Implementation of Virtual Maintenance Simulation Based Maintainability Analysis System LIU Hui，HAO Jian-ping The framework of virtual maintenance simulation -based maintainability analysis system was put forward. The system was designed according to its framework. The system consists of four function modules，virtual maintenance prototyping module, maintenance simulation module, maintainability analysis module and system management module. The system was developed with Jack software as the platform. With a mechanism as an example, all functions of the system were demonstrated.
Interface Designing of Particle System in Virtual Scene System GAO Ying, JIN Yan-tong, YANG Yong-qiang ,HUANG Jian-guo The general theory and applications of particle system were introduced and the thinking of object-oriented technology was proposed aiming at the phenomena that many particle systems realized but spread around. The realized particle system was integrated and encapsulated. A particle system module was developed, and the definition of interface and the relation of hiberarchy of particle system modeling were given, the model unified the interface of application program, and a concrete application was also given.
Design and Implementation of Visual Interactive Manipulationin Model Builder of VRML FENG Gui-zhen, CHI Jian-bin, WANG Chen, WANG Da-ming Virtual Reality Modeling Language (VRML) can be applied to construct the virtual reality based on Web. It is inconvenient to construct VRML scenes directly with the traditional method of text editing and testing in browser, owing to not providing the constructing way of what you see is what you get and visual and interactive manipulation. Accordingly, based on studying the current VRML standard, a model builder of VRML was developed, which used Visual C++6.0 as the system developing platform, implemented realistic image display of 3D model and dynamic browse by OpenGL, the standard graphic API, and offered visual and interactive manipulation, which made the users construct the virtual scenes based on Web without directly using VRML.
Research and Realization on CAD Model Transformation Interface for Virtual Assembly WAN Bi-le, LIU Jian-hua, NING Ru-xin, ZHANG Ye Aiming at the model transformation problem from CAD system to virtual assembly system, a multi-level representation structure of assembly model of virtual products was put forward，a model transformation interface based on neutral files was developed, and the structure, content and format of neutral files, information mapping and associating of model in the virtual environment were comparative-deeply discussed.
Simulation of Real-time Water Surface Based on Cg and OpenGL MA Jun, ZHU Heng-jun, GONG Jian-hua The effect of real-time water surface can consumedly enhance the immersion characteristic of virtual reality system. Based on Cg and OpenGL, some technologies including P-buffers, Bump Mapping, Projective Texture Mapping and Dynamic Texture Mapping were used synthetically to simulate a real-time water surface. In this simulation, some effects, such as reflection, refraction, wave, sun light reflection and caustics, were realized and the water surface was constructed only by two triangles.
Comparison Research of Different Control Strategies on Parallel Hybrid Electric Vehicle

WANG Bao-hua, WANG Wei-ming, ZHANG Jian-wu, LUO Yong-ge

Several control methods including baseline control, real-time adaptive control and fuzzy logic control used in parallel hybrid electric vehicle (HEV) are introduced and different advantages and disadvantages were also examined. According to the effectiveness and efficiency of those control methods, fuzzy logic control strategy was proposed based on its advantages such as high efficiency、adaptability and robustness.
Direct Torque Control of Induction Motors Based on Space Vector Modulation WEI Xin, CHEN Da-yue, ZHAO Chun-yu A model of direct torque control (DTC) of induction motor drives based on space vector modulation (SVM) was established, and its simulation research was performed. The torque ripple could be significantly reduced by SVM-based DTC scheme. The synthesized reference voltage vector that could exactly compensate current flux and torque errors was generated by using two PI controllers. Afterwards, the reference voltage vector could be converted into corresponding PWM signals by using SVM technique. The SVM-DTC was simulated in MATLAB/Simulink. Simulation results show the validity of the model.

Simulation Analysis of Shape Shifting Robot’s Tipover Stability

 LIU Jin-guo, WANG Yue-chao, LI Bin, MA Shu-gen It is so dangerous for the mobile robot to carry out the mission under uneven unstructured environment that if tipover incident happens, it will result in a series of problems such as system damage and mission failure. The shape shifting robot can change its configurations to adapt to the uneven terrain and improve its tipover stability. After the mobile robot’s tipover problem has been analyzed theoretically, stability pyramid and tipover stability index have been proposed to globally determinate the mobile robot’s static stability and dynamic stability. The tipover stability of the three-module track robot has been discussed when it is in shape shifting. And all of its five motile configurations have been tested by this technique under the combine disturbance of Pitch, Roll and Yaw. The simulation result has shown that this technique is effective for the analysis of mobile robot’s tipover stability, especially for the reconfigurable or shape shifting modular robot. Both theory research and simulation analysis have provided a valid reference for the shape shifting robot’s potential application.

Research on 2-DOF Parallel Manipulator with Redundant Actuation

YANG Gang, FU Xiao-yun, LI Bao-ren A 2-DOF parallel manipulator with redundant actuation was proposed to make the parallel structure more stable and meet the requirements of an underwater-simulated device. Based on the dynamic model and considering the distribution of the force on the actuated joints, a variable structure controller with two-folded sliding modes was designed for the manipulator, which was droved by hydraulic cylinders with uncertain parameters and disturbance. The control law was chosen based on Lyapunov stability theory. The effectiveness and robust of the proposed control are demonstrated by simulations.
Design of Novel ANN-Based SVPWM Controller PAN Ting-long, JI Zhi-cheng, XIE Lin-bo, SHEN Yan-xia The basic principle of space vector pulse-width-modulation (SVPWM) was analyzed, and a novel algorithm of SVPWM based on the multiple artificial-neural-network (ANN) was proposed. The calculation time is shortened, and the harmonic due to control delay is reduced because of the fast parallel computation and learning capability of ANN. A computer simulation model for direct vector control system of induction motor was developed using MATLAB/Simulink together with the Neural Network Toolbox. The simulation results demonstrate the feasibility of Multiple-ANN–SVPWM.
Simulation and Study of Composite Hydraulic System with Frequency Control and Variable Pump BAI Guo-chang, WANG Zhan-lin Based on the mathematical models of AC motor vector control and hydraulic cubage control, a model combined with electric and hydraulic was established in MATLAB. Simulation and analysis show that, with composite control, the model can improve the response performance of the system and the developing direction of this system is proposed. A new thought way for analyzing machine and electric systems was offered.

System Dependent Failure Probability ModelBased on Monte Carlo-Neural Network

LI Cui-ling, XIE Li-yang, LI Jian-feng

Dependent failure can significantly reduce the redundant system reliability, so it has been widely paid attention to in the engineering practice. According to the reliability theory and analysis of failure mechanism on the components, a component’s failure probability was regard to be the conditional failure probability with its stress, so that the mathematical expression for system dependent failure probability was given. Using Monte Carlo simulation, distributed type of conditional failure probability of the components was obtained; Extracting dependent failure information from given low-fold failure data and establishing the neural network model, its distributed parameters were obtained. The model can predict any multiplicity dependent failure probability, and also be applicable to other system with same components and environment and different sizes. An example is provided to illustrate the application, and its predictability is tested, which shows that the approach is accurate and feasible.
A Kind of Novel Blind Equalization Algorithm Based on Fractional Sampling Method SUN Li-jun, SUN Chao Blind equalization is an effective way to suppress the inter-symbol interference (ISI), which is caused by multipath fading communication channels. The super-exponential iteration (SEI) blind equalization algorithm has the advantage of good tracking capability of the time varying channel. However real channels are generally non-minimum phase systems, baud-spaced equalizers exhibit poor performance under this circumstance. Based on fractional sampling method, a new super-exponential iteration decision feedback blind equalization algorithm for severely nonlinear phase distortion channels was proposed. The simulation results show that the proposed algorithm with faster convergence rate acquires an improvement of about 7dB reduction in residual MSE as comparing with the MSE obtainable with the baud-spaced one.
Application study of Multi-Agent Based Simulation of Economies FU Xing, LIN Yin Multi-Agent Based Simulation of economies has gradually become a new modeling approach supplementing the traditional mathematical model of economies due to the distinctive performance in modeling of the complex properties of economic system. It has been developed in western countries for many years. U.S. economic model ASPEN which was developed by the Sandia National Laboratory is one of the representative achievements for microanalytic simulation. In China, research in this field was undertaken since the end of 90’s last century, and was made considerable progress. In the research of Multi-Agent Based economic simulation during recent years, the author developed a distributed platform，named DABS, for Multi-Agent Based Simulation, and imitated the ASPEN systematically, and made a preliminary discussion on some hot topics of China’s economy based on the simulation result of China’s economic model.
Novel Strategy of Motion Detection and Object Tracking Based on Robust Statistics HU Yu-suo, CHEN Hui-yong, CHEN Zong-hai  A novel motion detection method based on robust statistics was proposed. It used global motion estimation and hypothesis test to detect the independently moving objects in the video sequence captured by a moving camera. To improve the accuracy of the detection algorithm, occlusion effect was compensated by bi-directional motion estimation. Based on it, a robust active contour model was proposed to track the contours of the moving objects. The model was solved using Level Set method. Experimental results on real-world data show that the proposed algorithm can detect and track the moving objects correctly and reliably.

Multi-agent Simulation Approach to Validity Analysis of Systems

LI Hong-lei，GAN Ren-chu The current situation of study on the validity analysis of systems was analyzed. Complex adaptive system and its features were introduced. The advantage of CAS theory and its model in validity analysis of systems was pointed out. A simulation approach based on CAS modeling to validity analysis of systems was created. An example was introduced.

Modeling Production Scheduling Considering Stability

WANG Ke, LI Qi-qiang Solutions of traditional production scheduling models may lose their functions due to variation of decision parameters. Various uncertain factors that may lead to rescheduling in real production environment were analyzed for this problem. Models containing stochastic parameters were redesigned by using two stages stochastic programming considering production scheduling stability. The models not only guarantee the scheduling stability above a specified confidence level but also allow getting better performance at the cost of risk. Finally, a chemical scheduling simulation shows the advantages of the new model.
Design and Simulation Research for Controller of Induction Motor by Adaptive Backstepping Method SHEN Yan-xia, LIN Jin, JI Zhi-cheng The mathematic model of induction motor in the stator fixed reference frame was adopted. Under the condition that the parameters in motor are uncertain, using position signal, velocity signal, flux signals and current signals, an adaptive backstepping position controller was designed without parameters knowledge. Based on the MATLAB/Simulink, the model of this induction motor’s nonlinear position control system was set up. The simulation results show that this proposed controller can obtain better position control characteristic and the position tracking error goes to zero asymptotically.
Research on Multi-Sensor Management Prototype System Based on CORBA CHENG Hong-bin, ZHANG Feng-ming, ZOU Qiang Recently, multi-Agent based distributed software systems have been applied to many fields successfully. The multi-Agent technique was introduced into the multi-sensor management field to develop intelligent multi-sensor management systems based multi-Agent, and the general CORBA based prototype structure and development methods were proposed. The prototype system structures of fusion Agent and sensor Agent were designed. The distributed task decomposition strategies and control problems of sensor management based on multi-Agent were discussed, and the coordination and collaboration problems among Agents were described. This study provided guide in theory and methods for the real application system development.
PLPF Based Approach for Control of Vehicle ABS HUANG Dao-min, CHEN Yuan-di A state space model for ABS (Anti-lock Brake System) of four channels was set up. Considering the nonlinear characteristics of its control problem, a piecewise linear superposition system was built by PLPF (Piecewise Linear Polynomial Function). Since the subsequent state of a vehicle system was undetermined, a modified PLPF method was proposed for ABS control. System matrix could be determined utilizing parameters of a vehicle state of two time points, and control series could be determined accordding the optimal control based on PLPF.
Simulation and Jamming Model of Infrared Bait HONG Yang, ZHANG Ke, LI Yan-jun Nowadays, the methods that infrared baits antagonize missile of infrared guided are widely used. In order to research the interfere method, the models of simulated of infrared baits were established. A great number of simulations of applied tactic schemes of infrared baits under the different circumstances and battle conditions were conducted, and at the same time, the probabilities of schemes were evaluated. Finally, the suited tactic schemes were chosen, and meanwhile the models of simulation for the research of infrared missiles were provided.
Simulation of Temporal-Spatial Correlated Sea Clutter Based on Statistic Model OUYANG Wen, HE You, JIN Yu Sea clutter impacts seriously on the effect and efficiency of maritime surveillance radars. The research on sea model will benefit optimum detection algorithm design and performance prediction. Based on the theory of compound scatter, the amplitude distribution, temporal correlation of the same patch of sea clutter and spatial correlation of adjacent sea clutter patch were discussed. Method to produce the non-Gaussion temporal-spatical correlated sea clutter by using SIRP was proposed The estimation of important parameters of the speckle component and texture component and introduction of temporal and spatial correlation in sea clutter simulation were analyzed. Sea clutter data was simulated under the certain conditions. Results prove the validity of this scheme.
Flight Control System Simulation Framework Based on Object-Oriented Technology

SHANG Chong-yang, LIU Yan, GAO Zheng-hong

 On the basis of traditional Flight Control System (FCS) simulation methods, an object-oriented FCS simulation method combined with Simulink model (MDL) was proposed. The application of object-oriented software design technology in FCS simulation software framework was discussed. The idea of MDL parser and the sorting algorithm of control blocks were introduced. Such simulation method, in conjunction with the powerful visual modeling ability of Simulink, could implement general FCS simulation of visual modeling, high efficiency, easy maintenance and expansibility.
Estimation of Ship’s Oil Pollution Damage Based on An Artificial Neural Network YUAN Qun An artificial neural network approach was proposed to estimate the loss of oil pollution because of ship’s accidents. The artificial neural network model founded based on training patterns including damage value and its influenced factors by selecting ten cases from historical database. Then the emulation and training for the network were proceed with, and the parameters derived from the trained network could be used to evaluate relevant cases. Results show that the artificial neural network approach for the damage estimation of ship’s oil pollution has some advantages such as objective and reliability, and they can provide important proofs for claiming for ship’s oil pollution compensation and protecting environment.
Simulation and Analysis on Switched Reluctance Motor Nonlinear Characteristic under Chopped Voltage Control

TAN Guo-jun, KUAI Song-yan, HE Feng-you

 Depending on the switched reluctance motor φ-i-θ data, a three phase SRM nonlinear model under MATLAB/ Simulink environment was established , that instantaneous torque, flux and electromotive force of each phases could be worked out easily. The SRM electromotive force were decoupled under the chopped voltage control, which could overcome the nonlinear characteristic of SRM electromotive force. Finally, the SRM nonlinear model and electromotive force decoupled control prove to be effective.
Diagnosis of Working Conditions of Aluminum Reduction Cells Based on Fuzzy Neural Network LI He-song, MEI Chi1, TANG Qian, ZHOU Nai-jun, HUANG Yong-bo, ZHANG Jia-qi The wavelet and fuzzy theory were introduced into high-order BP Neural Network according to the frequency spectrum characteristics of voltage vibration signal and arrangement of working conditions. Diagnosis model of working conditions of aluminum reduction cells were developed based on the wavelet high-order fuzzy neural network which integrated the three promising technologies: wavelet transform, artificial neural network s (ANNs) and fuzzy logic. The structure of FNN was given and the membership function was developed according to the actual situation. All simulated reasons of working conditions were emulated on 320KA prebaked aluminum reduction cells. The feasibility of this novel method is proved by the simulation results.

Blind Source Separation Based on Signal Number Estimation

　

LI Guang-biao, XU Shi-min The determination of the number of unknown source signals when there are fewer sources than the mixtures in blind source separation (BSS) has always been an unsolved problem. Based on the application of BSS in array signal processing, a method of estimation signals number was proposed. Due to fourth-order cumulants, the method can improve the estimation performance. The detailed solution to the problem of number estimation was explained, and Monter-Carlo trials demonstrated that the performance of this method was better than the usual algorithms. The validity of the method in BSS is proved through experiments. Thus the method can solve the problem of estimation of signal number in BSS, it paves the way to wider application of BSS methods.  
Numerical Simulation of Response of Elevator and Occupants in Accident SHEN Jie, JIN Xian-long, PANG Feng The idea of elevator accident reconstruction and its modeling method were put forward. Using the response of occupants, the method of evaluating occupant safety was described according to the characteristics of elevator accident. Finally, considering the influence of the elevator protector, the accident environment and FE model of elevator system were established and calculated by the explicit finite element algorithm. Comparing the simulation results with real accident, the correctness of the method was proved.
Research on Trading Model of Electronic Broker in Second-hand Apartment Market ZHANG Zhen-hua, WANG Ding-wei The application problem of electronic broker in the second-hand apartment market of china was researched, and a trading model was proposed. The characteristic of this model is as follows: intelligent-agent searching, and returning a seller list ranked in descending order of preferential level; assigning every agent a KANBAN which indicates this agent’s state, so as to avoid confusion; based on the information feedback, description precision being highly improved; the one-to-one negotiation in a cycle improving efficiency and avoiding disorder; maximizing broker’s income and successful recommending ratio. When the two parties being matched, a multi-objective assignment model was constructed, whose objectives were to maximize the total satisfaction degree and the sum of the trading prices, and settle it by adding the efficiency matrices fuzzily, so that it was changed into a single-objective model. A computation example was given.

Computer Simulation Design and Illuminating Simulation of Automobile Freeform Headlamp Reflector

WANG Xiao, LIU Hui-xia, YI Yong, CAI Lan Freeform headlamp is one of the headlamps with great potentialities. The reflector of a freeform headlamp is a freeform surface which cannot be defined by mathematical functions and the design of which has always been a difficulty in the process of headlamp design. Designing a freeform headlamp was focused on by using computer simulation design. It mainly included: light source modeling, freeform reflector design and headlamp illuminating effect simulation. The practical designing result was given.
Output Tracking Control Design of Subminiature Rotorcraft CHEN Li, GONG Zhen-bang, LIU Liang The dynamics of a subminiature rotorcraft was given including flybar’s flapping. Further simplification of the control design process could be realized by dividing the rotorcraft dynamics into translational dynamics and attitude dynamics by using singular perturbation theory. The output tracking control design of the rotorcraft based on nonlinear inverse dynamics was described. The simulation results show that a desired trajectory can be tracked and the proposed control scheme is proved to result in global exponential stability and convergence in the trajectory error.

Comparison of Petri Net Based and UML Activity Diagram Based Workflow Modeling

WANG Wen-yuan, SHA Ji-chang, TAN Dong-feng Petri Net and UML Activity Diagram have both been play very import roles. But there are no researches on whether they are adaptable. It’s concluded that WFMS is reactive, coordinate and open when WFMS is analyzed. Since UML activity diagram has no proper semantics for workflow modeling, it has been proposed based on statechart. It was compared that how to use Petri Net and UML activity diagram to model workflow. Then the conclusions are drawn that Petri Net is fit for the modeling of closed and active system; UML Diagram is more fit for the modeling of open and reactive system; Petri Net is fit for the modeling of scare resources. Based on above, the conclusion is that UML Diagram is more fit for workflow modeling.
Design and Application of Tracking-differentiator for Autonomous Cruise System LI Zhi-gang, DU Zhen-hui, WANG Bao-guang For the longitudinal range sliding mode control of Autonomous Cruise System, tracking-differentiator was designed and applied to provide acceleration information, which could enhance the response characteristic of control system. Theory analysis and computer simulation prove that tracking-differentiator can track the vehicle relative speed measured by millimeter wave radar and get acceleration accurately. The performance of tracking-differentiator is good and design process is simple.
Design for Real-Time Visualization System of Crater Based on ROAM Algorithm ZHANG Rong-hua，ZHENG Gu-ping Real-time visualization of multi-resolution dynamic terrain, which is often used to meet the demand of the high fidelity of the virtual battlefield environments simulation and some 3D games, has attracted growing interest at home and abroad over the last decade. The design of the simulation loop and the real-time visualization of the crater based on the dynamic extension of ROAM algorithm was implemented preliminarily. The experiment testifies the feasibility of our previous study of the representation and visualization of dynamic terrain[1].
Simulation and Analysis of Radar Anomalous Performance in Evaporation Duct HUANG Xiao-mao, ZHANG Yong-gang, WANG Hua, TANG Hai-chuan Evaporation duct is a familiar abnormal structure of atmospheric refractivity, which has important influence on radar performance. To evaluate the capability of radar in evaporation duct environments, a model was proposed based on the parabolic equation numerical model of electromagnetic waves propagation and radar receiver theory. The proposed model was used to simulate the radar detection in different evaporation ducts conditions. And the anomalous characteristics of radar detection were analyzed according to the results of simulation.
Studies on Selecting Partners of Enterprises Dynamic Alliance Based on ACO GAN Yi, QI Cong-qian, DU Ji-tao The Microhabitat Ant Colony Optimization (MACO) algorithm was built up. When positive feedback being used, MACO made use of experience information and heuristic information with time parameters, and combined Microhabitat Information Differece when local being optimized, without running into the precocity of Genetic Algorithms and the stagnation of the basic ant algorithm. The selecting partners of the manufacturing enterprises dynamic alliance being the problem of multi-target optimizing, the target function of optimizing selecting was created. The problem of multi-target optimizing of the selecting partners was sloved with MACO. And the optimized answer was achieved.
Extension of Queue Scheduling Algorithm in NS2 GAO Wen-yu，WANG Jian-xin，CHEN Song-qiao  It was discussed how to extend the network simulator—NS2, especially how to extend queue scheduling algorithm in NS2, and the discussion was illustrated by implementation of a queue scheduling algorithm. The basic idea and key details of NS2 extension were given a detailed description, such as how to use packet header to car