Computer Engineering Commons^™

Disturbance Rejection Based Robust Control Approach For Servo System With Backlash, Chongwei Han, Peng Chao, Zhixiang Shi, Li Zhong

Journal of System Simulation

Abstract: With the rapid development of industry and science technology, the control performance requirements for servo system become higher and higher. Aiming at the servo system with backlash, a disturbance rejection based robust control approach is studied, which sees the backlash as external disturbance. It utilizes a disturbance rejection compensator to reduce the adverse effects caused by backlash, a mixed sensitivity based robust feedback controller to enhance the tracking control precision and robustness. The model of the servo system with backlash is built based on the analysis of system structure and work principle. The control principle, the robust disturbance rejection …

Research On Wind Turbine Test System Based On Jointsimulation, Zhongyue Song, Zhen Dong, Zhang Hao, Zhanqun Shi, Jiaojiao Ma

Journal of System Simulation

Abstract: As the test equipment of wind turbine can not simulate wind driven exactly and the impact of environmental factors is hard to be taken into account, the simulation results have larger errors. The problem is solved by establishing the virtual test bench in the way of combined simulation. The wind speed modelis optimized by combining the fitting of probability and the combinated wind speed model to drive the wind turbine;and the settings of some relevant contact force parameters are considered,which canmake the simulation results are closer to the actual situation. The credibilityof the system isdemonstrated and the validity …

Uav Attitude Control With Lqr Controller Based On Extended State Observer, Pan Jian, Changlong Liu

Journal of System Simulation

Abstract: Due to the external disturbances and parameter variations in the complex environment, the traditional linear quadratic controller (LQR) may induce instability to the controlled object. A control strategy of LQR based on extended state observer (ESO) is proposed, which aims to ensure the working reliability of the controlled object in complex environment. The nonlinear mathematical model of the quadrotor Qball-X4 is established. The ESO’s abilities of estimating and compensating the impact of internal/external disturbances simultaneously are used to improve the LQR attitude controller. Matlab/Simulink simulation and an experiment of trajectory tracking on the quadrotor Qball-X4 verify the validity …

Empathetic Computing For Inclusive Application Design, Kenny Choo Tsu Wei

Dissertations and Theses Collection (Open Access)

The explosive growth of the ecosystem of personal and ambient computing de- vices coupled with the proliferation of high-speed connectivity has enabled ex- tremely powerful and varied mobile computing applications that are used every- where. While such applications have tremendous potential to improve the lives of impaired users, most mobile applications have impoverished designs to be inclusive– lacking support for users with specific disabilities. Mobile app designers today haveinadequate support to design existing classes of apps to support users with specific disabilities, and more so, lack the support to design apps that specifically target these users. One way to resolve …

Automatic Identification Of Animals In The Wild: A Comparative Study Between C-Capsule Networks And Deep Convolutional Neural Networks., Joel Kamdem Teto, Ying Xie

Master of Science in Computer Science Theses

The evolution of machine learning and computer vision in technology has driven a lot of

improvements and innovation into several domains. We see it being applied for credit decisions, insurance quotes, malware detection, fraud detection, email composition, and any other area having enough information to allow the machine to learn patterns. Over the years the number of sensors, cameras, and cognitive pieces of equipment placed in the wilderness has been growing exponentially. However, the resources (human) to leverage these data into something meaningful are not improving at the same rate. For instance, a team of scientist volunteers took 8.4 years, …

Analyzing And Modeling Users In Multiple Online Social Platforms, Roy Lee Ka Wei

Dissertations and Theses Collection (Open Access)

This dissertation addresses the empirical analysis on user-generated data from multiple online social platforms (OSPs) and modeling of latent user factors in multiple OSPs setting.

In the first part of this dissertation, we conducted cross-platform empirical studies to better understand user's social and work activities in multiple OSPs. In particular, we proposed new methodologies to analyze users' friendship maintenance and collaborative activities in multiple OSPs. We also apply the proposed methodologies on real-world OSP datasets, and the findings from our empirical studies have provided us with a better understanding on users' social and work activities which are previously not uncovered …

Enhancing 3d Visual Odometry With Single-Camera Stereo Omnidirectional Systems, Carlos A. Jaramillo

Dissertations, Theses, and Capstone Projects

We explore low-cost solutions for efficiently improving the 3D pose estimation problem of a single camera moving in an unfamiliar environment. The visual odometry (VO) task -- as it is called when using computer vision to estimate egomotion -- is of particular interest to mobile robots as well as humans with visual impairments. The payload capacity of small robots like micro-aerial vehicles (drones) requires the use of portable perception equipment, which is constrained by size, weight, energy consumption, and processing power. Using a single camera as the passive sensor for the VO task satisfies these requirements, and it motivates the …

Investigating Dataset Distinctiveness, Andrew Ulmer, Kent W. Gauen, Yung-Hsiang Lu, Zohar R. Kapach, Daniel P. Merrick

The Summer Undergraduate Research Fellowship (SURF) Symposium

Just as a human might struggle to interpret another human’s handwriting, a computer vision program might fail when asked to perform one task in two different domains. To be more specific, visualize a self-driving car as a human driver who had only ever driven on clear, sunny days, during daylight hours. This driver – the self-driving car – would inevitably face a significant challenge when asked to drive when it is violently raining or foggy during the night, putting the safety of its passengers in danger. An extensive understanding of the data we use to teach computer vision models – …

Combination Forecasting Of Stock Index Time Series Based On Cooperative Game Theory, Luo Wei

Journal of System Simulation

Abstract: In view of the characteristics of nonlinear, large amplitude, frequent fluctuations in China's stock market, a prediction method of intelligent composite stock index time series based on the cooperative game is presented. The prediction model of stock index time series is established by using neural network method based on the correlations among the various economic indicators, and the development trend and laws of stock index time series are established by using the improved ARIMA method. The two methods are combined by importing cooperative game method. Simulation results show that the prediction accuracy of the presented method is controlled …

Real-Time Simulator For Spatial Information Networks Based On Analog If Signal Processing, Zeguo Yang, Ma Shang, Diaopeng Huang, Jianhao Hu, Lixiang Liu

Journal of System Simulation

Abstract: To solve the problem of real-time simulation of spatial information network with high dynamic network topology, a real-time simulator based on the IF signal processing is proposed. Compared with traditional channel simulator, it supports both the channel transmission characteristics like channel fading, Doppler shift, noise, and path delay, and the real-time simulation of dynamic network topology changes. The simulator supports 8~128 70 MHz IF (0~20 MHz signal bandwidth) emulated nodes with flexible link type configuration. The maximal fading depth is 100 dB, the maximal Doppler shift is 2 MHz, and the maximal path delay can reach up …

Research And Simulation Of Roots-Type Power Machine Control System Based On Fuzzy Pid, Yan-Jun Xiao, Yonggeng Wang, Jing Ran, Feng Hua, Yongcong Li

Journal of System Simulation

Abstract: For utilizing the domestic low grade waste heat resources, a Roots-type steam engine is developed. To make the roots engine stably output electric energy, an efficient constant power control system needs to be designed. The controlled object characteristics of the roots engine are analyzed; the modeling of the control system is established; and on this basis the fuzzy control algorithm is introduced. The fuzzy adaptive PID controller for the roots power machine constant power output is designed and the related MATLAB simulation is carried out. The results show that the Roots type steam power machine with fuzzy adaptive PID …

Application Of Finite Element Modification And Model Order Reduction In Temperature Control System, Xiaona Wang, Ye Ying, Qiyue Xu, Sebastian Marin, Michael Hohmann, Shuliang Ye

Journal of System Simulation

Abstract: A modification and model order reduction (MOR) method based on finite element model is proposed, which can be used in the design of simulation platform of furnace temperature control system. Based on the step response test of furnace behavior and the modification of finite element model's key parameters in ANSYS, the model reflecting the actual characteristics of furnace is obtained. Based on the software tool called mor4ansys using Krylo subspace reduction method, the state space model is obtained. The MATLAB/Simulink simulation platform based on state space model is built for more research work on furnace temperature control design. Based …

Online Synthesis Incremental Data Streams Classification Algorithm, Sanmin Liu, Yuxia Liu

Journal of System Simulation

Abstract: Online learning is the effective way to solve the sample's non-recurrence in data streams classification, and how to deal with the problem of sample deficiency is the critical point for improving online learning efficiency. According to the mean square error decomposition theory of the model's parameter estimation and the idea of cluster, the new samples are constructed by linear synthesis with the class center and the sample, which can improve the distribution information of sample and reduce the lower bound of parameter value. The online incremental learning is executed and the class center point is continuously updated. Through theory …

A Lightweight Modeling And Simulation Technical Framework For Complex Systems, Ji Hang, Junhua Zhou, Guoqiang Shi, Tingyu Lin, Junjie Xue

Journal of System Simulation

Abstract: Aiming at the modeling and simulation verification of complex systems, the paper established a lightweight simulation technical framework and a system building method. The simulation technical framework is built based on distributed network communication middleware and has graphic user interface, simulation management and run control modules, it packages effective and lightweight network middleware, object management, event management and time management and it is capable of interoperability and its members have abilities of reusable and combinable. The results show that the framework can supports flexible construction and effective simulation on complex systems.

Temperature Characteristics Of Contact Wire Under Different Driving Intervals, Hongwei Wang, Zhang Kai, Zhiyong Wang, Fengyi Guo, Liu Shuai, Zhang Qiong

Journal of System Simulation

Abstract: To reduce the wear of pantograph and catenary system while decreasing the headway, the temperature field of the contact wire is studied. A simulation model is established by using the COMSOL Multiphysics software. The effectiveness of the model is verified with temperature experiments. Temperature field of the contact wire of freight locomotive and passenger locomotive in different intervals is studied by simulation. The smaller the headway of trains, the higher the temperature value, and the shorter the balance process. Under the constraint of temperature field, the headway of freight locomotive couldn't be less than 180s under long term operation. …

Modeling And Simulation Of Islanded System With Wind And Storage Power, Ye Peng, Yaoning Hu, Minghui Sun

Journal of System Simulation

Abstract: With the consumption of primary energy and the severe environmental issues, the new energy power generation has been attracted much attention by scholars at home and abroad. As an important application form of new energy power generation, the operation of the islanded system with wind and storage power has a huge potential for future development. For the islanded system with wind and storage power, each mathematical model and the mathematical model of control system were established. In the electromagnetic transient simulation platform PSCAD, the corresponding electromagnetic transient simulation model was built based on the established mathematical model. The dynamic …

Analysis And Simulation Of Temperature Control For Battery Pole Piece Electromagnetic Heating Roller, Jing Ran, Feng Hua, Yonggeng Wang, Haiping Song, Yanjun Xiao

Journal of System Simulation

Abstract: With the application of electromagnetic heating roller on battery pole piece rolling,the processing technology, quality and efficiency of the battery pole piece are improved. The special heating technology of electromagnetic heating roller which involves multi-physics coupling in the process of conversion makes it difficult to control the heating process and determine the control index. By studying the electromagnetic heating theory, the mathematical model of electromagnetic heating roller is established and the simulation and analysis of the electromagnetic heating roller using MATLAB software and the finite difference method are carried out. The distribution, change rule and influence factors of the …

Eye Gaze Tracking In 3d Immersive Environments, Xincan Zhao, Shihao Pan, Yaping Wang, Tie Yun

Journal of System Simulation

Abstract: Aiming at the problem that human-computer interaction in immersive environments is entirely dependent on the body movement with low operational efficiency,a 3D eye gaze tracking method is proposed to gain the 3D gaze point of the user. Thus the interactive operation could be achieved, which provides a natural and bidirectional way for interaction. The Leap Motion controller is innovatively used to track the coordinates of eyes and the head position is tracked with the motion capture device. The gaze point under free movement can be estimated based on the mapping equation that is obtained in the initial …

Study And Performance Analysis Of Bar Tsv Structure, Zhensong Li, Miao Min

Journal of System Simulation

Abstract: A bar-through silicon via (B-TSV) structure is studied, and its 3D model and equivalent circuit model are proposed. The effects of design parameters formulas are investigated and concluded by a 3D electromagnetic solver. Performance comparison between B-TSV and the conventional cylindrical one is provided by simulation under the Ground-Signal-Ground configuration. The B-TSV structures are designed and fabricated in a printed circuit board (PCB) and the measured performance is given. Test results confirm that B-TSV has better performance than traditional one.

Modeling & Simulation Technology In Manufacturing, Zhang Lin, Longfei Zhou

Journal of System Simulation

Abstract: With the continuous deepening of the application of information technology in the manufacturing field, the informatization of manufacturing systems is developing from unit digital manufacturing to integration networked manufacturing, and then to the comprehensive digital, networked and intelligent manufacturing. As a comprehensive information technology integrating computer, model theory, and scientific computing, modeling & simulation technology plays an irreplaceable role during the development of manufacturing informatization and is widely applied in all phases of the whole product lifecycle, such as design, manufacturing, testing, maintenance, purchase, sales and other phase. This paper reviews and summarizes the research and application of modeling …

Research On Maturity Evaluation Technology Of Complex Digital Industrial System, Geng Chao, Shiyou Qu, Tingyu Lin, Guoqiang Shi, Yingying Xiao, Wang Mei, Qiudan Ma, Ji Hang

Journal of System Simulation

Abstract: Under the background of a new round of the innovation of science and technology and the revolution of industry, the complex digital industrial system is constantly innovating and shaping. Firstly, the paper established maturity evaluation model of the complex digital industrial system based on system engineering. Then, the paper proposed multi - index maturity analysis method and multi - enterprise maturity synthesis method of the complex digital industrial system. Combined with the digital industrial system of aerospace complex product, an evaluation example is presented. The results show that the maturity evaluation method can be used to standardize and guide …

Channel Capacity Analysis Of Diffusion-Based Molecular Communication Model, Cheng Zhen, Lin Fei, Yanjing Lei, Huiting Zhao

Journal of System Simulation

Abstract: At present, the research on the channel capacity of diffusion-based molecular communication (DBMC) model is very limited. In the slotted point to point communication scenario, considering all the inter-symbol interferences from all the previous time slots, the optimal decisive threshold is provided by using the criterion of minimum average error probability in the detection process for the receiver nanomachine, and the mutual information expression is derived in DBMC model. Thus channel capacity of this model is analyzed. The simulation results show that the different parameters have important influences on the channel capacity. Compared to the existed point to point …

Identification Of Closed Loop Projection Subspace For Motor Based On Hankel Correlation Function, Minghong She

Journal of System Simulation

Abstract: To solve estimation deviation problem of model parameter in the closed-loop system identification, the subspace identification model and state space model based on the estimation of the correlation function are presented, and through the correlation function estimation and zero space followed by projection, the block Hankel matrix of identification framework was filled so as to obtain the scope of the extended observability matrix; on the basis of the same projection on the time offset set of related data, the RQ decomposition of the projection is calculated by numerical calculation, and the dynamic estimation of the system model is obtained. …

High Frequency Blend Clips Matching Based Fire Sound Synthesis, Yin Qiang, Shiguang Liu

Journal of System Simulation

Abstract: Aimed at the problem which generated by fire sound simulation in virtual reality field, a new fire sound synthesis method was proposed. Most of the sound synthesis methods currently separate the fire sound into low and high frequencies for synthesizing. The influence of low frequency fire sound models was considered and the low frequency signal was synthesized based on the physical visual fire model data. The high frequency sound signal was synthesized based on high frequency blend clips matching method. According to the characteristics of the fire's high frequency, the different frequency bands of high noise signal …

Clustering Method Based On Graph Data Model And Reliability Detection, Yanyun Cheng, Huisong Bian, Changsheng Bian

Journal of System Simulation

Abstract: For the data in feature space, traditional clustering algorithm can take clustering analysis directly. High-dimensional spatial data cannot achieve intuitive and effective graphical visualization of clustering results in 2D plane. Graph data can clearly reflect the similarity relationship between objects. According to the distance of the data objects, the feature space data are modeled as graph data by iteration. Cluster analysis based on modularity is carried out on the modeling graph data. The two-dimensional visualization of non-spherical-shape distribution data cluster and result is achieved. The concept of credibility of the clustering result is proposed, and a method is proposed, …

Batik Dying Simulation Based On Diffusion, Yangtao Yu, Zhenlu Yu, Wenhua Qian, Keshi Zhang, Xu Dan

Journal of System Simulation

Abstract: This paper presents a three-layer model which is composed of wax layer, warp layer and weft layer. The wax layer wraps warp and weft layer which overlap together. According to Fick's second law and considering dye's diffusion, absorption and supply, a differential equation is built to describe diffusion process and this equation is discretized. Porosity, tortuosity and neighboring coefficient are used in the equation. Rectangular weave is simulated by using ellipse-distance model and blurred in HSV color space. Simulation shows that the satisfactory visual effect which closes to real batik cloth is acquired by the method and the algorithm …

Modeling And Computer Simulation Of Numerical Experiments On Laser Propagation Through Atmospheric Turbulence, Chunyi Chen, Huamin Yang, Bin Ren, Zhengang Jiang

Journal of System Simulation

Abstract: Focusing on numerical simulations of laser propagation in atmospheric turbulence, a method for determining the grid size of optical-field samples that need to be stored in a data file was first suggested, and a simulation scheme based on a parallel computer cluster was proposed. By performing simulation examples, both the average intensity of collimated fundamental Gaussian beams propagating through atmospheric turbulence and the change in spatial-mode composition of Laguerre-Gaussian (LG) beams travelling in atmospheric turbulence were studied. Analyses show that for the case of horizontal propagation, the use of a matching approach based on zero-order moment to determine …

Space Communication Network Cascading Failure Model Oriented System Combat, Zhu Lin, Shengliang Fang, Jinsong Wang, Fuxiang Wu

Journal of System Simulation

Abstract: According to the structure characteristics of space communication network, a node attack model for space communication network was designed. A space communication network cascading failure model was proposed by analyzing the assigning of initial load and the capacity of node, the judging regulation of node cascading and the reassigning algorithm of node load. The evaluation method of network robustness based on the loss ratio of operation loop was put forward. The validity of the model is illustrated by a case of combat system network cascading failure process. The simulation results also revealed the relationship between the cascading failures results …

Aerodynamic Simulation Of Multi-Dof Flapping-Wing Air Vehicle Of Bird-Like Based On Xflow Software, Yonggang Yang, Hanping Su

Journal of System Simulation

Abstract: The aerodynamic characteristics analysis of flapping-wing is of great significance to the design, manufacturing and control of the aircraft. In this paper, a simple motion model of multiple-Degrees-of- Freedom (multi-DOF) of “swing-torsion-bending and folding” is established by analyzing the flight characteristics of bird-like flapping wing. The flapping-wing air vehicle of multi-DOF is numerically simulated in the case of unsteady flow at low Reynolds number by XFlow software. The effects of flapping wing shape, frequency and inflow on surrounding air are analyzed. The simulation results provide theory and technique supports for the flapping-wing air vehicle'research and development.

Matlab Simulation For Electrically Excited Synchronous Motors With Low Switching Frequency, Qingqing Yuan, Bin Song, Yang Na

Journal of System Simulation

Abstract: Switch loss is one of the main energy consumption of the high power transmission system, while the low switching frequency approach is an effective way to improve above issues. However, it will result in a severe harmonic distortion and further affect the control performance. A selective harmonic elimination pulse width modulation (SHEPWM) strategy has been used to ensure the low energy consumption operation of a diode clamped three-level converter whose load is a high power electrically excited synchronous motors (EESM). For the SHEPWM's characteristics of specific harmonic elimination and harmonic energy moving on the high order, a simple high-pass …