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- Keyword
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- Simulation (131)
- Virtual reality (41)
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- Modeling and simulation (34)
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- Virtual simulation (18)
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- Traffic simulation (17)
- Permanent magnet synchronous motor (16)
- UAV (16)
- Unity3D (16)
- Energy consumption (15)
- Support vector machine (15)
- Collision detection (14)
- Deep reinforcement learning (14)
- Parameter identification (14)
- Publication Year
Articles 421 - 450 of 3363
Full-Text Articles in Physical Sciences and Mathematics
Unmanned Air Vehicles Launching Aircraft Combat System And Key Technologies For Penetrating Counterair, Minghao Li, Wenhao Bi, An Zhang, Wenxuan Sun
Unmanned Air Vehicles Launching Aircraft Combat System And Key Technologies For Penetrating Counterair, Minghao Li, Wenhao Bi, An Zhang, Wenxuan Sun
Journal of System Simulation
Abstract: Penetrating counterair is an important countermeasure to the anti-access/area denial environment. Under this operational requirement, the unmanned air vehicles launching aircraft (UAVLA)has received much attention due to the advantages of load quantity and variety, operational range and duration, and development time and cost. Based on the review of the concept development and supporting research related to the UAVLA, the top-level concepts of operations such as the component systems,operational process, operational events tracking, and information interaction of the UAVLA combat system (UAVLACS) are designed. The key technologies of the system are prospected from four aspects:intelligent cognition of battlefield situation under …
Opnet Based Simulation Of Hybrid Tdma Protocol For Helicopters Datalink, Yanfang Fu, Nan Zhang, Jianing Wei, Shaochun Qu, Ying Lu, Chang Liu
Opnet Based Simulation Of Hybrid Tdma Protocol For Helicopters Datalink, Yanfang Fu, Nan Zhang, Jianing Wei, Shaochun Qu, Ying Lu, Chang Liu
Journal of System Simulation
Abstract: For the current time slot allocation problem of the data link, an improved hybrid time slot allocation protocol based on grey relational analysis is proposed and implemented. Through the aggregation of throughput, delay and load of current message buffer by grey relational analysis, the comprehensive evaluation index is obtained, and the time slot is allocated dynamically. The fixed time slot allocation is also adopted to ensure that at least one time slot is available for nodes in the network.Simulation results show that compared with the fixed TDMA(time division multiple access) protocol and the P-TDMA(priority-TDMA) protocol, the proposed protocol …
Research On Opponent Modeling Framework For Multi-Agent Game Confrontation, Junren Luo, Wanpeng Zhang, Weilin Yuan, Zhenzhen Hu, Shaofei Chen, Jing Chen
Research On Opponent Modeling Framework For Multi-Agent Game Confrontation, Junren Luo, Wanpeng Zhang, Weilin Yuan, Zhenzhen Hu, Shaofei Chen, Jing Chen
Journal of System Simulation
Abstract: As the key technology of multi-agent game confrontation, opponent modeling is a typical cognitive modeling method of agent's behavior. Several typical models of multi-agent game confrontation,non-stationary problems, and meta-game theory are introduced; opponent modeling methods that concludes the frontier theory of opponent modeling are summarized, and the applications and challenges are analyzed. Based on the theory of meta-game, a general opponent modeling framework is constructed with three modules: opponent policy recognition and generation, opponent policy space reconstruction,and opponent exploitation. It is expected to provide theoretical and methodological reference for opponent modeling in multi-agent game confrontation.
Siamese Object Tracking Algorithm Combined With The Intersection Over Union Loss, Wei Zhou, Yuxiang Liu, Guangping Liao, Xin Ma
Siamese Object Tracking Algorithm Combined With The Intersection Over Union Loss, Wei Zhou, Yuxiang Liu, Guangping Liao, Xin Ma
Journal of System Simulation
Abstract: To improve the accuracy of the object bounding box regression prediction of the SiamRPN,solve the problem of low discrimination of positive samples in classification prediction and the lack of correlation between regression prediction and classification prediction, an improved object tracking algorithm of SiamRPN which combined with IoU(intersection over union) loss is proposed. A joint optimization module of IoU-smooth L1 is designed to optimize the IoU loss of the best positive sample and the smooth L1 loss of other positive samples jointly. According to the regression prediction results, the weighted classification prediction is performed on the positive samples with the …
Relative-Residual-Based Dynamic Schedule For Decoding Of Ldpc Codes, Fatang Chen, Hebin Li, Zhihao Zhang, Zhiqiang Mei
Relative-Residual-Based Dynamic Schedule For Decoding Of Ldpc Codes, Fatang Chen, Hebin Li, Zhihao Zhang, Zhiqiang Mei
Journal of System Simulation
Abstract: In order to solve the problems of the oscillation phenomenon and greedy characteristics in the dynamic scheduling decoding algorithm for low-density parity-check (LDPC) codes, the relative-residual-based dynamic schedule (RRB-BP) algorithm is proposed based on variable-to-check residual belief propagation (VC-RBP) algorithm. The variable nodes are grouped, then the relative residual value of the message passed by the variable nodes to the check node is taken as a reference, and the node with the largest relative residual value is updated in priority to accelerate the decoding convergence speed. For variable nodes oscillating in the decoding process, the posterior LLR (log likelihood …
Energy-Efficient Scheduling Of Multi-Objective Flexible Job Shop Considering Interval Processing Time, Hongliang Zhang, Renman Ding, Gongjie Xu
Energy-Efficient Scheduling Of Multi-Objective Flexible Job Shop Considering Interval Processing Time, Hongliang Zhang, Renman Ding, Gongjie Xu
Journal of System Simulation
Abstract: Based on the comprehensive consideration of economic indicators and environmental factors, the energy-efficient scheduling problem of multi-objective flexible job shop with uncertain processing time is studied. The interval number is used to describe uncertain processing time of the workpiece, and the optimization model for energy-efficient problem of interval flexible job shop scheduling is established to minimize the maximum interval completion time and total energy consumption. According to the domination relation of interval possibility degree, an effective interval multi-objective evolutionary algorithm is designed. The simulation experiments of the interval multi-objective evolutionary algorithm, SPEA-II and NSGA-II are carried out through 15 …
Particle Swarm Algorithm For Solving Emergency Material Dispatch Considering Urgency, Li Zhang, Huizhen Zhang, Dong Liu, Yuxin Lu
Particle Swarm Algorithm For Solving Emergency Material Dispatch Considering Urgency, Li Zhang, Huizhen Zhang, Dong Liu, Yuxin Lu
Journal of System Simulation
Abstract: In the early stage of major public health events, medical supplies are rapidly consumed and severely insufficient. In order to distribute medical supplies in a reasonable and efficient manner, research on the distribution of emergency medical materials is carried out. The entropy method is introduced to determine the urgency of demand points, thus could give priority to the demand points with high urgency and make the distribution routing as short as possible on that basis to realize the construction of a split delivery and multi-objective emergency medical materials scheduling model based on different urgency of demand points. Meanwhile the …
Design Of Optical Compound Eye Simulation Software For Small Aircraft Applications, Qiming Qi, Ruigang Fu, Ping Wang, Min Wang, Hongqi Fan
Design Of Optical Compound Eye Simulation Software For Small Aircraft Applications, Qiming Qi, Ruigang Fu, Ping Wang, Min Wang, Hongqi Fan
Journal of System Simulation
Abstract: Optical compound eye has the advantages of large field of view, multiple viewing angles and high resolution. With another advantage that it can conformal combine with small aircraft, optical compound eye has application value in reconnaissance and surveillance, target detection, image navigation and other aspects. An optical compound eye simulation software for small aircraft is designed for the current situation of long development period of optical compound eye design and high cost of flight test in practical applications. The software integrates compound eye imaging, aircraft simulation and data management, and each functional module is extensible. The simulation results show …
Mesoscopic Modeling And Simulation Of Mixed Traffic Flow Of Buses And Vehicles, Yiting Zhu, Yun Yan, Zhaocheng He
Mesoscopic Modeling And Simulation Of Mixed Traffic Flow Of Buses And Vehicles, Yiting Zhu, Yun Yan, Zhaocheng He
Journal of System Simulation
Abstract: Aiming at the problem that the existing mesoscopic simulation models only convert buses into several standard vehicles and ignore the movement difference between buses and vehicles, a mesoscopic simulation model of mixed traffic flow is proposed. In the process of road driving, on the one aspect, we consider the feature that bus speed is usually lower than vehicle speed, and correspondingly establish the reduction function of bus speed; on the other aspect, we consider the influences of bus-station queue overflow on the adjacent lanes, and correspondingly construct the lane-based speed model of mixed flow.Moreover, we use the …
Electrical Resistance Tomography And Flow Pattern Identification Method Based On Deep Residual Neural Network, Weiguo Tong, Shichao Zeng, Lifeng Zhang, Zhe Hou, Jiayue Guo
Electrical Resistance Tomography And Flow Pattern Identification Method Based On Deep Residual Neural Network, Weiguo Tong, Shichao Zeng, Lifeng Zhang, Zhe Hou, Jiayue Guo
Journal of System Simulation
Abstract: Aiming at the low accuracy of inverse problem imaging and flow pattern recognition in electrical resistance tomography (ERT), a two-phase flow electrical resistance tomography and flow pattern recognition method based on the deep residual neural network is proposed. The finite element method is used to model the ERT forward problem to construct the "boundary voltage-conductivity distribution-flow pattern category" dataset of various gas-liquid two-phase flow distributions. The residual neural network for ERT image reconstruction and flow pattern identification of gas-liquid two-phase flow is built and trained. The two outputs of the residual neural network are processed respectively to obtain …
Study On Invulnerability Of Urban Agglomeration Passenger Traffic Network Considering Time Characteristics, Chengbing Li, Yunfei Li, Peng Wu
Study On Invulnerability Of Urban Agglomeration Passenger Traffic Network Considering Time Characteristics, Chengbing Li, Yunfei Li, Peng Wu
Journal of System Simulation
Abstract: The cascading failure invulnerability study of comprehensive passenger transport network in urban agglomeration is helpful to improve the safety and transportation efficiency of intercity travel. In order to be consistent with the actual situation, a comprehensive passenger transport network model for urban agglomerations is constructed based on multi-layer complex network theory and actual passenger flow. The passenger transport network cascading failure invulnerability model considering time characteristics is established with unit time step. The spatial and temporal evaluation indexes are put forward to analyze the network situation in each period. Taking Hu-Bao-E-Yu urban agglomeration as an example, the results show …
Research On Ofdm Signal Detection Method Based On Intrawell Stochastic Resonance Of Bistable System, Gaohui Liu, Ying Liang
Research On Ofdm Signal Detection Method Based On Intrawell Stochastic Resonance Of Bistable System, Gaohui Liu, Ying Liang
Journal of System Simulation
Abstract: In order to solve the problem of weak OFDM (orthogonal frequency division multiplexing)signal detection at the receiver in OFDM transmission system, the intrawell stochastic resonance of bistable system is combined with the OFDM signal enhancement and demodulation process. Analytical expression is derived for the time required to change from zero state to potential well state for the intrawell stochastic resonance system under the excitation of multicarrier signals, and the energy loss of multicarrier signals in one symbol caused by the transient response is analyzed. The steady-state output equation of system is derived, and the problem of superimposing the …
Architecture Design And Prototype Verification Of Railway Vehicle Dynamics Cloud Platform, Junjie Sheng, Zhao Tang, Shaodi Dong, Shuyang Wu, Hao Liang
Architecture Design And Prototype Verification Of Railway Vehicle Dynamics Cloud Platform, Junjie Sheng, Zhao Tang, Shaodi Dong, Shuyang Wu, Hao Liang
Journal of System Simulation
Abstract: Since almost all the software in the railway vehicle field is controlled by foreign capital, it is difficult to catch up with the development of independent vehicle system software based on single machine deployment mode in a short time. In view of this, a set of autonomous and controllable vehicle system dynamics software architecture based on cloud platform is proposed. Based on the railway vehicle system dynamics and cloud services, a cloud platform with automatic process modeling, cloud computing,post-processing analysis is built. A simulation model of a trailer caris applied in the platform, and compared with the SIMPACK …
A High Resolution Reconstruction Method Of Temperature Distribution In Acoustic Tomography, Lifeng Zhang, Yu Miao
A High Resolution Reconstruction Method Of Temperature Distribution In Acoustic Tomography, Lifeng Zhang, Yu Miao
Journal of System Simulation
Abstract: Accurate measurement temperature distribution is important for industrial production. In order to solve the number of mesh divisions will impact reconstruction accuracy in acoustic tomography, the TR-RBF (Tikhonov regularization-radial basis function) reconstruction algorithm is rebuilt to reconstruct the temperature field with high resolution. The Tikhonov regularization is used to reconstruct the ultrasound time of flight (TOF) to obtain a temperature distribution on coarse grids, and use local weighted regression method to smooth processing; use RBF neural networks to predict the temperature distribution on fine grids. Through numerical simulation with and without noise, compared with ART,SVD and Tikhonov, the proposed …
Research On Cooperative Adaptive Cruise Control Strategy Based On Improved Mpc, Qiming Wang, Jiangyue Jiang, Zhichao Lü, Hanzu Zhang
Research On Cooperative Adaptive Cruise Control Strategy Based On Improved Mpc, Qiming Wang, Jiangyue Jiang, Zhichao Lü, Hanzu Zhang
Journal of System Simulation
Abstract: To solve the problems of environmental interference, sensor noise and poor tracking stability of time-varying speed, an improved MPC (model predictive control) algorithm based on KF (kalman filtering) is proposed. The longitudinal kinematics model of CACC(cooperative adaptive cruise control)between vehicles is established and the discrete state space equation is created. KF is used to reduce the noise of state variables, and at the same time, the prediction model is designed for robustness. The CACC control objectives are analyzed under different working conditions and the objective optimization functions are created. Verify by building Simulink and CarSim co-simulation model, the simulation …
Simulation Of The Market Exclusive Competition Between Platforms, Wen Zheng, Zhe Zhang, Jingyi Zhu
Simulation Of The Market Exclusive Competition Between Platforms, Wen Zheng, Zhe Zhang, Jingyi Zhu
Journal of System Simulation
Abstract: As for the problem of an exclusive competition between the platforms, 2 competing PlatformsAgent, 100 ConsumersAgent and 300 SellersAgent are introduced and encapsulated into a closed market environment in BarriersModelSwarm. A two-sided market system is constructed with the cross-network externality. Through BarriersObserverSwarm, the Agents attribute information and behavior strategy are cross-called, and the virtual connection class Orderand ArrayList class in the Virtual Connection Classes are generated to run cyclically. The unilateral dependence degree of Consumers/SellersAgent is triggered, which restores the exclusive of the two-sided market competition in comparison with the platform transaction scale, market concentration, and platform cumulative capital. …
Modulation Recognition Algorithm Based On Truncated Migration And Parallel Resnet, Yecai Guo, Qingwei Wang
Modulation Recognition Algorithm Based On Truncated Migration And Parallel Resnet, Yecai Guo, Qingwei Wang
Journal of System Simulation
Abstract: A truncated migration data preprocessing algorithm is proposed for the problem of limited time series characteristics of the signal extracted by convolutional neural network. The distance unit at one end of the sampling matrix is truncated, migrated to the other end to form a new matrix, allowing the convolutional neural network to extract more sampling points and compare more symbolic information.An improved parallel ResNet is proposed, which focuses on features in both horizontal and vertical directions simultaneously by two parallel branches. The results show that the algorithm has an accuracy rate of about 10% higher than that of ordinary …
Turbofan Engine Fault Prediction Based On Evidential Reasoning And Belief Rule Base, Hailong Zhu, Ruxia Jia, Liang Zhang, Wei He
Turbofan Engine Fault Prediction Based On Evidential Reasoning And Belief Rule Base, Hailong Zhu, Ruxia Jia, Liang Zhang, Wei He
Journal of System Simulation
Abstract: Aiming at the fault prediction problem of a turbofan engine, a fault prediction model based on evidential reasoning (ER) and belief rule base (BRB) is proposed. In order to describe the health state of turbofan engine, ER algorithm is adopted to fuse the state information. Combined with prior knowledge, a hybrid driven simulation prediction of BRB model is established. Projection covariance matrix adaptive evolution strategy (P-CMA-ES) is used to optimize the model parameters. The validity of the model is verified by experiments. Experimental results show that the proposed method not only accurately predicts the probability of failure …
Image Dehazing Network Based On Densely Connected Residual Block And Channel Pixel Attention, Weidong Jin, Shuli Zhang, Peng Tang, Man Zhang
Image Dehazing Network Based On Densely Connected Residual Block And Channel Pixel Attention, Weidong Jin, Shuli Zhang, Peng Tang, Man Zhang
Journal of System Simulation
Abstract: Abstruct: A lot of research achievements have been made in image dehazing based on neural network,but there aiming at the fog residue, even the color distortion and texture loss, in complex outdoor image dehazing, an image dehazing network based on densely connected residual block and channel pixel attention is proposed. Densely connected residual blocks are used to extract and fuse the features of foggy images,and the repair module with channel pixel attention mechanism is used to repair the color and texture of the feature maps. The experimental results show that, compared with the existing methods, the proposed method and …
Research On Motion Recognition And Tracking For Space Survey And Launch Tasks, Bin Ren, Xiaoyu Wang
Research On Motion Recognition And Tracking For Space Survey And Launch Tasks, Bin Ren, Xiaoyu Wang
Journal of System Simulation
Abstract: Space survey and launch task has high precision and long cycle, and needs to be exposed to direct sunlight for a long time, so that the non-contact action calibration and comparison in a virtual working environment is an efficient way to improve the mission completion success rate. Aiming at the real-time motion tracking of aerospace personnel, a keyframe optimization algorithm for the action recognition is proposed. According to the bone data in the depth image, the bone features are extracted, and the keyframes are extracted by the feature threshold. The characteristic data of the keyframe is input into bi-directional …
Sensorless Control Of Pmsm Based On An Anfis Optimized Flux Sliding Mode Observer, Huilin Zhang, Yujie Jin, Haima Yang
Sensorless Control Of Pmsm Based On An Anfis Optimized Flux Sliding Mode Observer, Huilin Zhang, Yujie Jin, Haima Yang
Journal of System Simulation
Abstract: Aiming at the low estimation accuracy of rotor speed and position and the system chattering in sensorless control of permanent magnet synchronous motor (PMSM), an adaptive neuro-fuzzy inference system (ANFIS) is proposed to optimize the flux sliding mode observer(FSMO). Compared with the traditional sliding mode observer, the FSMO improves the estimation accuracy of the rotor flux. The FSMO optimized by ANFIS realizes the on-line adjustment of the observer gain and reduces the system chattering. The improved PLL improves the estimation accuracy of the rotor speed and position. A simulation platform is established to verify the results which show …
Simulation Of Unmanned Tank Clusters Cooperative Combat Based On Military Rules, Chunyan Wang, Hao Ren, Minchi Kuang, Danfeng Wu, Xiangshu Cao, Heng Shi
Simulation Of Unmanned Tank Clusters Cooperative Combat Based On Military Rules, Chunyan Wang, Hao Ren, Minchi Kuang, Danfeng Wu, Xiangshu Cao, Heng Shi
Journal of System Simulation
Abstract: Modern warfare is developing towards the unmanned, informatized, and intelligent form. Being the important combat equipment in the future land warfare, unmanned tanks have greater advantages of mobility, safety, and economy. Single unmanned tank can not fulfill the complex tasks of large-scale battles as the cooperation of unmanned tank clusters can do. Focuses on the collaborative applications of unmanned tank clusters, the single unmanned tank system model is established, including dynamic control, decision-making, and weapon armor. A collaborative perception model of unmanned tank clusters is designed considering the unmanned tank's own state and the fusion situation. Based on the …
Modeling Of Traffic Flow Velocity Control Strategy For Human-Machine Mixed Driving At Signalized Intersections, Jianxu Zhang, Shuai Hu, Hongyi Jin
Modeling Of Traffic Flow Velocity Control Strategy For Human-Machine Mixed Driving At Signalized Intersections, Jianxu Zhang, Shuai Hu, Hongyi Jin
Journal of System Simulation
Abstract: In order to analyze the influence of speed control strategy of autonomous vehicle on the operation characteristics of traffic flow, a deterministic decision-making model for intersections with artificially driven vehicles considering the driver's influence on the acquisition of driving information is constructed. An automatic driving speed control strategy considering the influence of the speed of preceding vehicle is proposed, and the continuous Cellular Automata update rules for signalized intersections are constructed respectively. By introducing the different penetration rates of automatic driving, road saturation and control area length parameters, the influence of CAV speed control strategy on the traffic …
Research On Passenger Ship Evacuation Simulation Based On Social Force Model, Qimiao Xie, Shuaishuai Guo
Research On Passenger Ship Evacuation Simulation Based On Social Force Model, Qimiao Xie, Shuaishuai Guo
Journal of System Simulation
Abstract: Aiming at the influence of group behavior and different evacuation methods on the passenger ship evacuation process. Three evacuation methods of passengers arriving at the assembly stations with and without group behavior are provided, and the passenger assembly time, congestion area, congestion timing and duration are analyzed. The simulation results show that the group behavior has a significant effect on the passenger assembly time and increases the variation range of the passenger assembly time, and the congestion area with and without group behavior remains the same. The influences of group behavior on the congestion timing and duration are complicated, …
Layout Planning Of Metro-Based Underground Logistics System Network Considering Fuzzy Uncertainties, Wanjie Hu, Jianjun Dong, Rui Ren, Zhilong Chen
Layout Planning Of Metro-Based Underground Logistics System Network Considering Fuzzy Uncertainties, Wanjie Hu, Jianjun Dong, Rui Ren, Zhilong Chen
Journal of System Simulation
Abstract: Aming at the network design and optimization of metro-based urban underground logistics under uncertainties, the facility components of two-tier metro-based underground logistics system (M-ULS) are proposed. Focus on the comprehensive costs and system utilization rate, a M-ULS network flow assignment model is established based on the expectation of environmental benefits of underground freight transport. a M-ULS network location-allocation-routing fuzzy random programming model is established, and a crisp linearization method is presented. A solution portfolio combining discrete binary chaos particle swarm optimization-genetic algorithm and exact algorithms is designed for combinatorial optimization. Effectiveness of the presented models and algorithms is verified …
Variable Pitch Control Of Wind Power Generation System Based On Wiener Model, Yue Xu, Li Jia, Xuanyi Fu
Variable Pitch Control Of Wind Power Generation System Based On Wiener Model, Yue Xu, Li Jia, Xuanyi Fu
Journal of System Simulation
Abstract: Strong nonlinearity and large fluctuation are the characteristics of wind power generation system. Quickly controlling the output power of wind turbines within the rated range under wind speed random changes is the major problem of wind power system control. Aiming at the pitch control of 5 MW wind turbines, a pitch control scheme for wind power generation systems based on the Wiener model is proposed. On the basis of the special structure in which the linear and nonlinear links of the Wiener model can be separated, the controlled object of a generalized wind power system with linear properties …
Parallel Live Performance Simulation Based On A Multidimensional Hierarchy And Application, Jingsi Yang, Tianyu Huang, Gangyi Ding, Lijie Li, Peng Li
Parallel Live Performance Simulation Based On A Multidimensional Hierarchy And Application, Jingsi Yang, Tianyu Huang, Gangyi Ding, Lijie Li, Peng Li
Journal of System Simulation
Abstract: A parallel simulation method is proposed for modern live performance. By decomposing the live performance process from the top down, this method assists creators in delivering stage design and control with time and space constraints, which is unattainable for traditional live performances. A multi-layer constraint hierarchy is constructed to apply parallel simulation to art performances. The live performance procedure is continuously optimized by leveraging the circulation of data between virtual and physical stages. The parallel simulation method for stage space has been applied to a digital TV stage for ten years. The experiments show that parallel live performance simulation …
Dynamic Obstacle Avoidance Control Of Three-Order Multi-Robot Cooperative Formation, Yuchao Zhang, Yuan Jiang, Jiyang Dai
Dynamic Obstacle Avoidance Control Of Three-Order Multi-Robot Cooperative Formation, Yuchao Zhang, Yuan Jiang, Jiyang Dai
Journal of System Simulation
Abstract: Aiming at the obstacle avoidance and consensus control of underwater vehicles formation in a 3D complex environment, a cooperative formation dynamic obstacle avoidance control algorithm is proposed. An adaptive repulsion gain term based on the speed of dynamic obstacles is established and it is introduced into the repulsion potential field function to enable the robot to safely avoid static and dynamic obstacles. The potential field function based on the gain term of the potential field and the communication weight between the AUVs are defined to solve the robots of easy self collision and leaving the formation. The total acceleration …
Research On Time-Dependent Vehicle Routing Problem With Multiple Time Windows, Nan Li, Rong Hu, Bin Qian, Huaiping Jin, Naikang Yu
Research On Time-Dependent Vehicle Routing Problem With Multiple Time Windows, Nan Li, Rong Hu, Bin Qian, Huaiping Jin, Naikang Yu
Journal of System Simulation
Abstract: Aiming at the time-dependent vehicle routing problem with multiple time windows (TD_VRPMTW) that considers urban traffic congestion, a hybrid discrete gray wolf optimizer (HDGWO) is proposed. In the HDGWO, a new grey wolf individual updating formula is designed, and the integer coding method based on customer permutation is adopted, so that the algorithm can directly perform the global search based on GWO individual updating mechanism in the discrete problem solution space.A population initialization strategy based on the nature of the problem is designed to generate the initial population with high quality and diversity.The information exchange formula of …
Rigid-Liquid Coupling Simulation Of Liquid-Filled Spacecraft Based On Openfoam, Zhijun Song, Zongyu Chen, Lü Jing, Tianshu Wang
Rigid-Liquid Coupling Simulation Of Liquid-Filled Spacecraft Based On Openfoam, Zhijun Song, Zongyu Chen, Lü Jing, Tianshu Wang
Journal of System Simulation
Abstract: Aiming at the design of the spacecraft attitude control system, a simulation software for the rigid-liquid coupling calculation of the liquid-filled spacecraft is built on the basis of the open source CFD software OpenFOAM. In the moving boundary problem, the N-S equation in the non-inertial frame is derived to improve the calculation efficiency, which avoids a large number of grid conversion calculations of the moving grid method in the traditional CFD software. PIMPLE algorithm is used to build the sloshing dynamics solution module, and the variable step length Runge-Kutta method is used to build the attitude …