Volume18  Number 5  (2006)

Title Author   Abstract
Assessment for Surface-to-Air Missile Weapon System EffectivenessBased on UML ZHOU Feng, ZHOU De-yun The surface-to-air missile weapon system effectiveness was analyzed and assessed applying UML. The purpose was to improve the surface-to-air missile weapon system effectiveness in course of constructing information engineering, to frame the metric space, to further analyzeand contrive the schemes facing to all fundament objects from assessment for firepower unit effectiveness and complete the high layer of computer engineering. A conclusion was drawn that the way or direction improving the kill probability of firepower unit effectiveness was obtained through improving the precision of control and guidance under the circumstance of information sustainability.
Modeling Air Combat Situation Assessment byUsing Fuzzy Dynamic Bayesian Network SHI Jian-guo, GAO Xiao-guang, LI Xiang-min Automatic and accurate situation assessment is essential for unmanned combat air vehicles (UCAVs) to conduct and maintain their operations autonomously and effectively. The assessment forms the basis of threat assessment and plays an important role in implementing autonomous control and optimization for UCAVs. It is also a fundamental issue in developing combat decision-making support system for manned combat air vehicles (MCAVs). A novel approach was proposed as an attempt to tackle this challenging problem. A model based on discrete fuzzy dynamic Bayesian network was derived for UCAVs’ situation assessment. A detailed theoretical analysis on the model and its inference method was given. Relevant simulation experiments were conducted and the results were discussed. It is shown that the presented model can predict accurately changes of the situation in a varying dynamical environment and has a good performance in terms of effective noise filtering from observations.
Simulation of Launch Dynamics of LRMLRS WANG Guo-ping，RUI Xiao-ting It is very important to realize the simulation of launch dynamics of Long Range Multiple Launch Rocket System (LRMLRS) for optimizing and improving the performance of the system. Launch and control dynamics of simple control LRMLRS was deeply studied in theory, computation and test. The launch dynamics model and launch dynamics equations of LRMLRS coupling rigid bodies and elastic bodies were established. The simulation system of launch dynamics of LRMLRS was established. The simulated results of vibration characteristics, response of MLRS in launching process were verified by series of tests.
Ameliorated Simulation Method of Compound K-distributed Clutter JIANG Bin, WANG Hong-qiang, REN Shuang-qiao, GUO Gui-rong To solve the question which is not considered for the realizable linear filter of physics in the simulation of compound K-distributed clutter at present, the statistics characteristic of the clutter model and simulation method of ZMNL(Zero Memory Nonlinearity) were firstly studied. Then adopting minimum phase feature and complex cepstrum technology, the technique of the realizable filter of physics was proposed based on these. Furthermore, the method of generation of random K-distributed sequences was put forward profoundly. Finally, the simulation was processed and the results prove both validity and veracity of the method. The clutter generated by this method can be used in the simulation of radar signal, analysis of radar image and optimization of radar signal processor.
Study of Seesaw Effect for Dynamic Model of Tubular Exchanger MA Jin, WANG Bing-shu, MA Liang-yu, GONG Xian Seesaw effect leads to the false dynamic trend for tubular exchanger real-time model. Compared with the character of real exchanger device, the dynamic curve of fluid outlet temperature is reverse when the inlet temperature of fluid changes in step. The computing formula of fluid outlet temperature and modeling hypothesis were analyzed to point out the cause of seesaw effect, and then the criterion to avoid it was given. The simulation test shows that the conclusion is correct. This method can be applied in real-time model of tubular exchanger.
Lightweight Formal Verification Methodof Mission Space Conceptual Model Research HE Xiao-ye, XU Pei-de, SHA Ji-chang Conceptual Model of Mission Space(CMMS) is the first abstraction of real world military knowledge, and is the business base for simulation system development. Therefore the quality of CMMS is the key to the quality of simulation system based on it. The research for Verification, Validation and Accreditation(VV&A) Technology of CMMS is very important. Essentially, CMMS is the knowledge representation or requirement acquisition in military domain, so qualitative representation is the main,but the quantitative description is the minor. Evidently traditional method of output analysis is unsuitable for CMMS. The lightweight formalization method to verification of mission space conceptual model (MSCM) was introduced. The formal verification process was put forward. Some formal verification models was constructed.
Cause-and-Effect Relationships Tracing in Analysisof Large-scale Campaign Simulation SHI Feng, HOU Hong-tao, LI Qun, WANG Wei-ping In results analysis of the large-scale campaign simulation, the analysis of cause-and-effect relationships tracing is one of most important steps. From causalities tracing,  the bugs of models and simulation can be found. And the key events and event sequence deciding for fight results in simulation process can be known, so that the inherent rules of campaign in a higher level can be found, and so on. To solve causalities tracing problem, the theoretical and practical troubles were studied, and shortcomings of methods for the problem now. A new approach that is a behavior modeling based methodology was put forward. This methodology was based on data of simulation results, got behaviors and causalities from the data, and built the behavior models which described causality specially. The cause-and-effect relationships could be traced based on these models. Some kinds of tracing problems were discussed in a certain extent.

Simulation Study on Nonlinear Control System for X-Cell50 Helicopter

 HUANG Bing-hong, LI Dong-hai, LAO Da-zhong, ZHENG He-hua Based on nonlinear decentralized theory, a nonlinear decentralized controller was designed for the pose stabilization of X-Cell50 helicopter in vertical flight. This simple-structured and easy-to-realized controller does not require the precise math model, however, the integral action included in it compensates unknown factors of plant. Simulations compared with sliding mode control, show that the proposed control system overcomes the disadvantage of sliding mode control just as chattering phenomenon and steady-state error. It is important that the excellent robust performance withstanding the outside disturbances and dynamical uncertainties is obtained by using the nonlinear decentralized controller.
Feasibility Research on Two Missiles’ Cooperative Location PENG Rui-hui, WANG Guo-hong, CHEN Shi-ju, YUAN Jian-quan The feasibility research on two missiles’ cooperative location was done, and the condition of the two missiles’ effective location was concluded. The cooperative location of the two missiles was researched by means of information share. The result indicates, by means of information fusion, the location precision of single missile can be improved a lot. And the preconditions are : one is that both missiles are far from the target; and the other is that one missile is far from target, but the other one isn’t. And the location precision can be influenced by the position error of the missile itself.
Nonholonomic Motion Planning for Free-Falling CatUsing Quasi-Newton Method GE Xin-sheng, LIU Yan-zhu WEI Bao-gang The motion planning problem of a free-falling cat was investigated. Nonholonomicity arises in a free-falling cat subject to nonintegrable velocity constraints or nonintegrable conservation laws. When the total angular momentum is zero, the attitude motion equations take on nonholonomic constraint. The control of system can be converted to the motion planning problem for a driftless system. The equation of dynamics of a free-falling cat wasobtained by using the model of two symmetric rigid bodies. Based on the input parameterization, the continuous optimal control problem was transformed into the discrete one. The quasi-Newton method of motion planning for nonholonomic multibody system was proposed. The effectiveness of the numerical algorithm is demonstrated by numerical simulation
Numerically Simulating Non-gaussian Random Processeswith Specified PSD, Skewness and Kurtosis JIANG Yu, CHEN Xun, TAO Jun-yong, ZHANG Chun-hua Non-gaussian random process is usually simulated by the method of Zero Memory Nonlinearity(ZMNL). However, its iterative process is time-consuming and it cannot ensure the precision of the simulation of non-gaussian random processes with specified power spectral density, skewness and kurtosis. Through theoretical derivation, a new algorithm based on IFFT and time domain randomization for the simulation of non-gaussian random processes with specified PSD, skewness and kurtosis was proposed. The numerical experiment is carried out and the results coincide with that from the theory. This shows that the algorithm is effective.
Research for Configuration Problem of Product FamilyBased on Tabu Search Algorithm LUO Xing-gang, WANG Ding-wei , JIANG Hui-yan, CHEN Dong-ming The most satisfying configuration solution needs to be found from effective configuration results of product family. Traditional methods could not be applied to the problems with large amounts of configurable items because of large search space. A mathematical model for ATO configuration problems of product family was proposed and Tabu Search algorithm was designed to solve this model. Dynamic penalty, frequency list, multi-stage search and configuration pool were used to improve the algorithm. The result of simulating indicates that this method is effective.
Study on Simulation of Hydraulic Pipelines’ Dynamic CharacteristicBy Simulink Software TIAN Shu-jun, ZHANG Hong It is essential to study pipelines’ dynamic characteristic and their simulation method for the optimizing design and performance analysis. A simulated method was introduced to the pipelines’ dynamic characteristic based on the idea of hydraulic pipelines’ model of sectional lumped parameter with the dynamic friction and input & output model of bond graph. The hydrodynamic shock test proves that the simulation method is suitable for pipelines’ dynamic analysis. The model of pipelines and the simulation results can give useful information to improve the design of hydraulic manifold block and other pipeline nets.
Simulation Study for One Kind of Stereo Computer Vision Scheme WANG Xiao-min A computer vision solution scheme for the automatic landing of an unmanned helicopter on ship was examined from the view of engineering application. A series of computer vision algorithms such as Sobel filter and Fast Hough Transform were adapted and integrated to get the relative positions between the helicopter and ship, from which their relative movement parameters could be obtained. A new kind of Fast Hough Transform was developed to detect the linear parameters, and the speed of which is 10 times faster than the standard Hough Transform. The new Hough Transform makes the stereo vision scheme very robust to noise. Computer simulation results indicate that the presented algorithms are robust and reliable.
Algorithm of Feature Selection for Semantic Video Classifier WEI Wei, ZHAO Xue-long, LIU Feng-yu, XU Man-wu Classifier performance could be improved by selecting the most important features from high dimension feature set. A method of classification based on approximated Bayesian error feature selection algorithm (ABFSA) was proposed.In order to get the distinctive value partition of feature, the neighborhood of mean for each class was preserved. Then, the residual value field of feature was divided. Backward sequential feature selection, a heuristic search strategy was used in the merging step of quantity partition. At the same time, quantity complexity was remarkably reduced. The results of experiments comparing to other feature selection methods indicate the algorithm can effectively select features.

Adaptive Immune Evolutionary Programming and Application

in Function Optimization

CHEN De-bao, ZHAO Chun-xia Four operators, such as clone, hyper-mutation, selection and memory of adaptive immune evolutionary programming, were improved based on combining immune system’s mechanism and principle of evolutionary programming. Diversity function and local degeneration algorithm were used to select and renew clone cells, and the characters of diversity for cells population were increased. Premature integration was avoided Because of over inbreeding in cells population in conventional methods. Adaptive mutation of cells population was realized by using hyperbolic tangent function to determine mutation probability without considering limitation of affinity. Memory cells were composed by half population with high affinity, and the half populations with low affinity in original generation were replaced. The analysis of reasons and merits for improved part were proposed. The main steps of the algorithm were given and the convergence of adaptive immune evolutionary programming were formulated. In simulation experiments, different functions were optimized by the presented algorithm, and the results show that the algorithm is valid.
Research on an Algorithm with Self-Tolerant Abilityin Hardware Immune System WANG Xin, LUO Wen-jian, WANG Xu-fa Research on hardware immune system is still in the initial stage. There are many problems to be solved including how to avoid autoimmunization, etc. A novel algorithm for the issue of autoimmunization was proposed, which was an inevitable problem when designing a hardware immune system. The algorithm endowed the hardware immune system with a certain extent of capability of self-tolerance by deleting self-matching detectors according to co-stimulation. It increased the accuracy of detection and decreased the ratio of false positive. Results of simulation experiments proved the availability of the new algorithm.
Study on Application of Genetic Algorithmin Discrete Variables Optimization HE Da-kuo, WANG Fu-li, MAO Zhi-zhong According to lots of discrete variable optimization problems in practice, the defects of applying continuous variable optimization to solve discrete variable optimization problems were studied. The characteristics of discrete variable optimization and genetic algorithm were associated. Thus, the discrete crossover operator and discrete mutation operator were proposed to make the genetic operator search in discrete space. Based on the theory of linear search, the discrete leading operator was proposed so as to improve the local searching capability of genetic algorithm, that led the population to local optimization and implemented rapid discrete searching. The study on two practical discrete variable optimization problems proves the validity of this algorithm in solving discrete variable optimization problems.

Improved Algorithm of Two-Step Texture Mapping

JIANG Ju-lang, ZHANG You-sheng, XUE Feng, HU Min The process of two-step texture mapping is composed of S mapping and O mapping. As the conventional S mapping algorithm inevitably produces discontinuous textures on the media surface, the realistic effect is badly damaged. The media surface was divided into two symmetrical parts, and the texture plane was also separated into two parts which were symmetrically mapped onto the two parts of the media surface using the method of preserving equal ratio of areas. The area nearby the joint was smoothed using the weighted interpolation algorithm so as to sew the two textures without joint lines. The texture rendered by the following O mapping is continuous on all the surfaces of the object and has less distortion.
Weibull Regression Model Based on MCMCand Its Application in Reliability LIN Jing, HAN Yu-qi, ZHU Hui-ming, CHEN Jie Weibull regression model was discussed, which is used widely in the family of Bayesian accelerated failure-time models. As for the productions whose life distributions belong to Weibull distribution, the MCMC method was brought forward based on Gibbs sampling to simulate dynamically the Markov Chain of the parameters’ posterior distribution. From this, the parameters’ Bayesian estimation of the Weibull regression model was given in the condition of the random truncated test and when the prior distribution of the failure rate belonged to the Gamma distribution, which improved the precision of the numeration. Also the data’s simulation was utilized to show the process of setting the model by using the BUGS package. It proves the objectivity and validity of the model.
New Approach to Decoupling Problem of Imaging Rotationin Single Channel-Controlled Air Defense Missile BU Yan-long, NIU Yi-feng, SHEN Lin-cheng In infrared homing seeker of single channel-controlled air defense missile, the hardware devices such as gyro and so on were used to solve the coupling problem of imaging rotation. A new approach was proposed which eliminated the coupling effect by software means. On the condition that the primary optical axis of the seeker was fixed to the missile top, the expressions of imaging compensation were educed by analyzing imaging laws of the moving target relative to the rotating seeker. An estimation algorithm based on the coupling image was used to realize real-time tracking for the angle velocity. After discussing some relative problems such as glint and fabric noises, a filter based on wavelet decomposition and weighted smoothness was utilized. The simulation results show this approach can effectively solve the coupling problem of imaging rotation.
Criterion Search Algorithm and its Applicationto Motif Finding in DNA Sequences DU Yao-hua, LI Dong-dong, WANG Zheng-zhi Motif finding is one of the fundamental problems in computational biology with important applications in finding regulatory signals. Though many algorithms have been developed, very few of them can obtain all motifs from the unaligned DNA sequences. A novel criterion for three subsequences was proposed , which was deduced through exploring valid paths in the layer graph. Then this criterion was used as prune rule in the exhaustive depth first search algorithm, criterion search algorithm (CRISA), to find all putative motifs rapidly. Analysis of the computational complexity and error probability proves that CRISA is efficient in most motif finding problems. Some tests using simulated and real biological data were done and the results show that CRISA is more efficient than other exhaustive search algorithms, and its search speed is even faster than that of many non-exhaustive search algorithms.
Comparison of Adaptive Filtering Algorithmsin Noise Cancellation Application: A Simulation Study LIU Shi-jin, ZHANG Yu-feng, Chen-wen-lue, ZHAO Xing-bi The theory of noise canceling and the method for abstracting the desired signal from strong background noise were described by using adaptive filtering and the LMS algorithms、NLMS algorithms and RLS algorithms  were compared. The results of computer simulation show that all of these adaptive algorithms can improve the detection of weak signal in strong background noise. In comparison, the RLS algorithm performance is much better than LMS algorithm and NLMS algorithm. Besides, the convergence speed is much faster and the behavior of the RLS filter coefficients is much more stable, and it has faster beginning convergence rate, lower misadjustment noise, and better robustness against noise and disturbance.
Topology Matching Method for Structured P2P Systems LI Zhen-yu, XIE Gao-gang, MIN Ying-hua, LI Zhong-cheng An event-driven based method was proposed to solve the topology mismatching problem of structured P2P systems. In this method, when joining a structured P2P system, based on the global information of the system, a peer is guided to find a physically close neighbor to connect with. If the overlay topology changes as peers join or leave the system, only affected peers are adjusted. The method neither solely relies on global information nor solely relies on local information of the system, but a good cooperation. This character reduces the overhead this method caused. Intensive simulation experiments on CAN overlays show that the event-driven algorithm can achieve average logical/physical link latency reduction rate by up to 65%，outperforming the combination of SAT-Matching and landmark binning which can achieve the reduction rate by up to 50%. Meanwhile, the overhead caused by this method is very small.
Efficient Method to Control Queue Lengthfor Mixture Flows of TCP and UDP YUE Guang-xue, ZENG Zhi-feng, WU Qi-yue, ZENG Nan-gui Based on the analysis of TCP flow control stochastic differential equation (SDE) model, in view of UDP having no flow control mechanism like congestion control and differential equation which takes window-based control being unable to describe the character of UDP running process, the original TCP flow control stochastic differential equation was modified. By means of adding UDP affections to the changing of router’s queue length, a new model was set up to analyze the mixture flows of TCP and UDP. After getting the root of steady state packet’s discarding possibility, the original RED queue length control method for TCP flow could be applied to the mixture flows of TCP and UDP. The simulation result shows that the improved method of RED queue length control is fit for not only TCP flows but also the mixture flows of TCP and UDP. With this method, actual router queue length can be kept fluctuating around the vicinity of expected queue length.
Missile Defense Radar Simulation System ZHAO Feng, LI Dun, WANG Xue-song, XIAO Shun-ping This paper presents a distributed, modularized and expandable missile defense radar functional simulation system analyzing and modeling its main mathematical modules, based on characteristics of ground-based phased array radars in missile defense system and principle of High Level Architecture(HLA). Simulation is carried out whose result verifies the efficiency. The successful exploitation of the system will supply the analyses and evaluation of the whole missile defense system efficiency with performance and basis.
Design and Implementation of Star Pattern Simulatorfor Use of Space Surveillance WANG Zhao-kui, ZHANG Yun-lin  The star pattern simulator system was proposed and developed for simulations and experiments of optical-based space surveillance. The simulator system is composed of high-class graphic workstation and high-resolution liquid crystal display systems. The optical character of nature celestial bodies such as star, sun, moon and earth can be displayed real time. The target spacecraft can be simulated and displayed based on a sphere illumination model. The simulator system can be applied in simulations and experiments of optical-based space surveillance sensors as well as star sensors.
Modeling and Simulation in RDSS System LI Qing-li, LIU Zhi, XUE Yong-qi, BAI Zhi-quan Radio Determination Satellite Service (RDSS) is a system that can provide accurate subscriber positioning and short message service to thousands of subscribers by using two geostationary satellites. Based on the research on the positioning theory of RDSS system, a positioning error model was established and a simulation system was developed. The hardware architecture, the simulation software and the simulation method of the RDSS simulation system were also proposed. In the simulation system, most of the operating conditions and operating states of the RDSS system can be simulated and most of the technical parameters of the RDSS positioning terminal can be measured easily. The presented RDSS simulation system can greatly benefit the development of the RDSS positioning terminal.
xPC-based Hardware-in-the-Loop Simulation of CertainLarge Flexible Multi-body Structure Satellite YUAN Jin-peng, YANG Di, ZHAI Kun, ZHANG Zi-long xPC real-time simulation system was introduced. By right of xPC, Hardware-in-the-Loop Simulation (HILS) system of certain large flexible multi-body structure satellite was designed. During the experiment, xPC was further studied: an xPC host computer controlled two xPC target computers at one time. One xPC target computer was used for imitating on-board computer, and the other one used for imitating outside environment of on-board computer. The final hardware was introduced to HILS system step by step after that the corresponding rapid control prototype worked successfully. The whole system development is based on model-based system design theory. Experiment results validate the presented method.
Study on Web-based Shiphandling Training System XIE Cui , LIU Xiu-wen, JIN Yi-cheng ：Based on Web-based simulation theory, a prototype of the web-based shiphandling training system was designed and implemented, which aims at overcoming the weakness of high expenditure, long developing period and the limited accessibility of numerous marine simulation systems. The research focuses on the feature, architecture, 3D modeling, interaction and integration of this system. This system adopts Java to construct a web-based three-level architecture, which is open and strong compatible. The system creates an interactive and immersible virtual navigation world by using VRML. As a result, it allows many users to perform shiphandling and decision-making training online from anywhere, anytime. This training platform provides a portable and flexible training paradigm for maritime education and training.
Research of HLA-Based Multi-Federation Collaborative SimulationManagement System for Complex Product Design GUO Bin, FAN Wen-hui, XIONG Guang-leng The requirements of complex product design for collaborative simulation technology and its environment were analyzed, and the features of collaborative simulation system were discussed using HLA according to transparency, heterogeneity and expandability. A kind of collaborative simulation management method using client/server structure was proposed for complex product design in order to overcome a deficiency of transparency of HLA, which could manage federates effectively and simultaneously. In addition, the architecture of collaborative simulation management system was proposed using the method, and the implementation of prototype of the collaborative simulation management system was described.
Method for Distributed Simulation Data CollectionBased on Temporal Database WU Ze-bin, LI Wei-qing, JIANG Xia-jun, WU Hui-zhong  Current simulation data collection systems were hardly optimized with temporal information. A method based on temporal database was proposed.The architecture for distributed simulation data collection was designed first. Making reference to Historical Relational Database Model and extending traditional relational database, a temporal database model was proposed to distributed simulation data collection system. Then the archetype for this model was designed and implemented including data index mechanism, storage implementation and query optimization. Compared with the data collection using pure file or using general commercial relational database by contrast experiments, the advantages of this method were demonstrated. Thinking of its fast collecting and high-quality query, it is especially applicable for data collection system oriented to simulation replaying and real-time query.
Research for Time Management of Simultaneous Eventand Distributed Simulation WANG Xue-hui, HUANG Ke-di The research on the transient message problem and simultaneous reporting problem was discussed, which are the most difficult core issue in the global control mechanism based on the Global Virtual Time (GVT) algorithm. The definition of the GVT and the difference from LBTS were introduced, and then the transient message problem was analyzed and a simple synchronous GVT algorithm was provided. The simultaneous reporting problem was further discussed and the basic asynchronous GVT algorithm was offered. The consistent cut and two-cuts mechanism were described, and on this condition, the two-cuts GVT algorithm was put forward., How to design and achieve this improved GVT algorithm was described in detail.
Investigating Underestimation Effect of Poisson Samplingon Packet Delay Dynamics Based on Simulation WANG Kai, LI Zhong-Cheng, YANG Feng, WU Qi, BI Jing-Ping Sampling technique is elemental and important for network measurement. It is traditionally believed that Poisson sampling is unbiased, which makes it being widely used in network active measurement area. And it is well known that the unbiased estimation of Poisson sampling is true when network state is considered. As it is coming to be an important problem to measure the packet performance of user flow, there are not empirical efforts to investigate the performance of Poisson sampling on packet performance measurement from user’s view. By using various actual Internet traffic datasets in simulation experiment, the difference of packet delay statistics between Poisson sampling results and user flow was systemically investigated. Poisson sampling systematically underestimates the statistics of packet delay, and the error degree decreases with the increasing of system utilization and has no relation with the frequency of Poisson sampling. Then the reason of above simulation results was analyzed.
Analysis and Implementation of Modeling Environmentfor Network Security Research LIN Si-ming, CHENG Xue-qi, Ma-Ming Following the formal description of network modeling environment, the network models could be divided into three degrees of virtualization. For network security research, a conception of high-fidelity modeling with three degrees of virtualization was proposed and an NS2 based prototype system was implemented. The architecture, implementation and performance were described and evaluated. A sample of worm modeling with real exploit packets was given and finally some problems and future work were also addressed.
Handling Stability Simulation Researchon Bus with Air Suspension ZHANG Jian-wen, GUO Er-sheng, HUANG Zhi-guo The air spring has the ideal nonlinear character. The vehicle with air suspensions has lower vibratory frequency and lower dynamic load of the wheels. It gains better ride comfort, handling stability and safety, minimizing the damage to the road. The handling stability simulation research on bus with air suspension was made, using the methods of virtual prototype technology. Through the ADAMS/car software, a full air spring suspension vehicle dynamic simulation model was built and the simulation on the handling stability was carried out. The simulation and test result are almost the same by the comparative of them.
Filtering and Calibration for Fastrak Data and Its Application in Virtual Surgery ZHONG Yun-fei, XIONG Yue-shan, TAN Ke, GUO Guang-you Electromagnetic tracking device Fastrak is mostly applied in virtual surgery system to aid the location for medical instrument. How to integrate Fastrak into the OpenGL graphics interface and how to filter and calibrate data in complicated and high noise environment were studied.. In order to keep virtual surgery stable and accuracy, FFT algorithm was used and a band-pass filter was to eliminate the disturbed noise, the reasonable data were achieved and the filtering and calibrating method has been successfully applied in virtual arthroscope surgery system.
A Method to Generate Character Animation on 3D Terrain SHI Min, ZHU Deng-ming, WANG Zhao-qi, LIN Bi-ying A method for character animation generation on 3D uneven terrain was given. First, a novel footprint generation method was proposed. Then the individual method was adopted to generate the particular motion based on simplified three-level model, that footprint constraint was added . The synthetical curve was introduced to control the motion of center of mass, and the inverse kinematics method with constraints was used to control lower limbs motion, and the forward kinematics method was used to generate upper-body motion. Appreciate human motion was generated by synthezing the motion of center of mass, the motion of lower-body and the motion of upper-body. Finally, some experiment results were demonstrated. The results indicate the generated motion using this method is realistic and real-time, thus the method can be applied to generate and control real-time human motion in complex 3D terrain environment.
Heavy Cargo Airdrop Simulation with 3D Animation KE Peng, YANG Chun-xin Simulation software for cargo airdrop system was designed and realized based on DirectX. Simulation software for multi-level-multi-chute cargo airdrop system was developed based on the simulation technologies with 3D animation and airdrop system simulation. The advantages of these technologies and their applications in airdrop system simulation were pointed out. Many useful functions were realized, which included data management and analysis, system dynamical computation, parachute dynamical calculation, instant query of key parameters, 3D animation demo of whole airdrop process and safety evaluation for the cargo extracting from the plane. The final software and its engineering application were introduced and the further research were noted. Simulation results and the animation of this software well agreed with the test videos. This software can be applied to the design and simulation of other airdrop systems as well as the training systems of paratroopers and athletes.
DFS Forecast Control Based on Takagi-sugeno Fuzzy Logical Ratiocination YOU Yong, WU Cheng, YOU Jen-sheng Because the moment of inertia of the centrifuge is quite big, a problem for driving control at big moment of inertia arises: the influence of time delay of centrifuge enlarged. Dynamic Flight Simulation (DFS) system’s high-G flight moment fuzzy rules based on Takagi-Sugeno fuzzy logic was proposed. By fuzzy classical analysis for Multi-Operating input value, the control principle was gained using generalized predictive control (GPC) in the neighborhood of sampling point. This method’s effect is proved by simulation experimentation.
Inverse Kinematics of Robotic Manipulators Based on LS-SVM YANG Yan-xi , LIU Ding , XIN Jing A new approach to solve the inverse kinematics of robotic manipulators based on least squares support vector (LS-SVM) is presented. Compared with the RBF neural networks, the LS-SVM possesses prominent advantages: over fitting is unlikely to occur by employing structural risk minimization criterion, and the global optimal solution can be uniquely obtained owing to the fact that its training is performed through the solution of a set of linear equations. Also, the LS-SVM need not determine its topology in advance, which can be automatically obtained when the training process ends. The simulation results are presented for a 2-DOF rigid robotic manipulator, which validate the effectiveness and feasibility of the proposed method.
Tracking Control of Nonholonomic Mobile RobotsBased-on Dynamics Model XIAO Ben-xian, ZHANG Song-can, LIU Hai-xia, ZHAO Ming-yang, WANG Qun-jing To solve the problem of path tracking for nonholonomic mobile robots with two drivable wheels, a new simple controller was designed based on the dynamic and kinematic models of mobile robot. Also the neural network was used to deal with unmodeled disturbances, and the stability of the controller was shown through the Lyapunov function. Finally, the effectiveness of the controller is demonstrated by simulation results.
Decentralized Adaptive Control for Robot ManipulatorsBased On Neural Network DONG Chao-yang, WANG Long, WANG Qing, ZHANG Ming-lian A decentralized adaptive control for trajectory tracking of robot manipulators is presented. The system is considered as a set of nonlinear subsystems with nonlinear uncertainties and interconnections. The tracking problem is tackled with decentralized controller. For each subsystem, an output feedback linearization is employed, and neural networks are used to compensate the system errors, the disturbances and the interconnections, which can simplify the design of the controller, improve the dynamic performance and make the system robust. Simulation results show that the system has a good tracking performance.
Study of Robust Control for Stratosphere Airship Attitude WANG Xiao-liang, SHAN Xue-xiong Based on the six degree of freedom (6DOF) nonlinear dynamic model of airship, the dynamic mathematical model of airship attitude was given. Combined the dynamic equations with the movement equations, the mathematical model of airship attitude were built. Then, Using the input/output feedback linearization approach and Lyapunov method, a control law of airship attitude is designed, which guarantees that the airship attitude exponentially tracks the desired attitude. Simulation results show that, precise attitude control is accomplished in spite of the uncertainties in the close-loop system.
Optimal Tracking Control for Time-Delay Systemswith Persistent Disturbances LIU Wen-chao, HU Nai-ping, LI Gui-li For time-delay systems with persistent disturbances, a successive approximation algorithm of optimal tracking control was proposed. First, the optimal tracking control problem of linear systems with state time-delay was transformed into the optimal control problem. Second, the linear two-point boundary value (IPBV) problem with both time-delay terms and time-advance terms was transformed to a sequence of nonhomogeneous linear TPBV problems without time-delay terms and time-advance terms with the successive approximation algorithm. A optimal control law was obtained. And then, by taking the finite-times iteration of the compensating sequence, a suboptimal control law was obtained. Lastly, the optimal control law was transformed into the optimal tracking control law.
Ship Steering Control Based on SA-Reinforcement Learning Algorithm YE Guang, GUO Chen Ship course control is closely related with navigation security, maneuverability and economy. Based on simulated annealing and reinforcement learning algorithm, a hybrid intelligent controller was proposed to ship steering. With the advantages of various intelligent algorithms, the controller can overcome the influence of the wind, wave and flow, the uncertainty of the ship steering, and the limitation that accurate data are hard to get for the disturbance and the error in instrument measuring. Al last, the results of the simulation show that the ship course can be properly controlled when changeable wind and wave exist.
Evaluation for Data Fusion System Based on Generalized Relative Entropy LIU Yan-yan, WU Xiu-qing Evaluation for data fusion system is discussed based on relative entropy. The method measures relative information gain