Engineering Commons^™

Robust Control Of Free-Floating Two-Flexible-Link Space Manipulator Based On Observer, Xiaoyan Yu, Chen Li

Journal of System Simulation

Abstract: The joint motion robust control and optimal flexible vibration control of a free-floating two-flexible-link space manipulator based on linear observers was discussed. The dynamic model of a free-floating space manipulator with two flexible links was established by the momentum conservation and the Lagrange equations. Based on singular perturbation approach and choosing appropriate local coordinate frame, a slow subsystem and a flexible-link fast subsystem were obtained. The corresponding controllers were proposed for the two subsystems, which was the linear observer based robust slow subsystem controller and the linear observer based flexible link fast subsystem optimal controller. Numerical simulation demonstrates …

Research On Force Compliance Of The Hydraulic Control System In Major-Motion Mechanism For Manipulator, Geqiang Li, Jingwei Zhang, Yuesong Li, Bin Zhou, Shuye Ma

Journal of System Simulation

Abstract: The force compliance method of the hydraulic control system in major-motion mechanism was proposed during the forging process. Taking the major-motion mechanism of the forging manipulator as the target, the inverse kinematics model of major-motion mechanism was established, and the dynamic model of hydraulic control system was built. Through taking the pressure as the controlled variable, the model of the lifting hydraulic control system was obtained by using the co-simulation technology. Based on the principle of the horizontal buffering system, the model of the buffering hydraulic system which was made up of the buffering cylinder and the accumulator …

In-Cylinder Flow Analysis And Verification Of Opposed-Piston Two-Stroke Engine, Fukang Ma, Changlu Zhao, Zhenfeng Zhao, Wang Hao, Yu Xia, Cao Yan, Jiqing Zhang

Journal of System Simulation

Abstract: The effects of flat piston uniform scavenging chamber, flat piston non-uniform scavenging chamber and pit piston non-uniform scavenging chamber on the in-cylinder flow were analyzed. Uniflow scavenging zero-dimensional model was used to qualitative analysis in-cylinder flow organizational process and influence rule for opposed-piston two-stroke engine. Results show that uniform scavenging chamber can organize swirl and increase scavenging efficiency and non-uniform scavenging chamber can organize tumble and increase turbulent kinetic energy. Scheme 3 is favorable to organize tumble and maintain the in-cylinder turbulence intensity, which is increased by 150 percent.

Dfig Grid Connection Simulation Method Used For Transient Analysis Of Black-Start, Liqing Liu, Zengqiang Mi, Du Ping, Yuliang Wan, Yuan He

Journal of System Simulation

Abstract: Establishing a grid connection model of doubly-fed induction generator based wind turbine (DFIG) could be useful in the research and verification of black-start strategy in isolated power grid containing wind power. A DFIG grid connection simulation method based on Simulink was proposed. Through analyzing the operation characteristics of doubly-fed induction generator in no-load and grid-connected conditions, its dual-operation simulation model was established. According to the grid-connection theory of DFIG, the established doubly-fed induction generator model was combined with wind turbine, converter and other built-in modules, and the DFIG grid connection model was built with its control system added. …

Eigen-Value Combination Approach For Speech Enhancement, Huijuan Lu, Yaqing Liu, Yanqiu Liu, Guan Wei

Journal of System Simulation

Abstract: In order to further suppress noise, a kind of speech enhancement algorithm based on Eigen-value merge was proposed. Eigen-values combination was used to improve the speech quality on the basis of the classic embedded pre-whitening subspace methods. The study shows that, after decomposing the covariance matrix of speech signals with noise, the larger Eigen-value component mainly includes speech information, and the smaller Eigen-value component mainly contains noise. Sorted by Eigen-values from small to big, the adjacent large Eigen-value component replaces with small Eigen-value component, which can effectively suppress noise and improve the quality of speech. Compared with other speech …

Gm-Cphd Filter With State-Dependent Clutter, Lili Ma, Xiaoshan Qin, Jinguang Chen

Journal of System Simulation

Abstract: For many sensors the clutters observed are easier to concentrate in the area around targets, namely the state-dependent clutter, which is different from the known clutter distribution in traditional filtering algorithms. So, the accuracy the real-time performance and of traditional multi-target tracking will be greatly degraded. To solve this problem, a kind of GM-CPHD filter with state-dependent clutter was proposed. The relationship between clutter and state was modeled. The clutter intensity was recalculated according to the distribution of clutter in the whole surveillance area and applied to update process; at the same time, in order to reduce the time …

Research On Static Behavior Of Xx-Joints Based On Ansys, Pan Ying, Linxiao Qin

Journal of System Simulation

Abstract: Nonlinear finite element analysis was used in the ultimate bearing capacity on planar XX-joints by ANSYS software. The stress distributions of the joints were demonstrated, the main failure modes of the joints were determined, and the influences of some fundamental geometric parameters on the ultimate strength were the research points. The results show β (diameter ratio of the branch to the chord), θ (axial angle of the chord and the branch), γ (the ratio of the diameter of the chord to the thickness of the walls of the chord) are the main …

Research Of Impact Point Accuracy Of One-Dimensional Trajectory Correction Projectile Based On Monte Carlo, Xiaoyun Lei, Zhian Zhang

Journal of System Simulation

Abstract: After the one-dimensional trajectory correction projectile out of the muzzle, various disturbance factors caused the impact point dispersion. Monte Carlo method was utilized on the shooting accuracy analysis. Based on the practical test datasets, three major factors were determined, namely, time delay of opening-damper mechanism, error of drag coefficient and measurement error of target. As to the disturbances, function randn was used for the analysis of the three major factors on the flat of Matlab. According to error distribution of the factors, the probability distribution and dispersion of the impact point were obtained. The maximum and minimum ranges of …

Potato Storage Temperature Prediction Control Based On Pso And Esns, Junxia Liu, Xinrong Xiong, Hu Bing

Journal of System Simulation

Abstract: According to the current situation of potato storage and serious waste of raw materials and human resources of potato processing enterprises, combined with temperature data characteristics of potato storage from Xinjiang Great Russell Agricultural Science and Technology Development LTD., and control effect of the conventional control methods which is not ideal, a new temperature predictive control method was proposed, which rolled to optimize the input control variable by using particle swarm optimization algorithm and get the actual output values, use ESNs to forecast the temperature in the storage, the system was corrected by deviation between forecasting output and actual …

Improving Microbiological Safety Of Low Moisture Food Products Using Radio Frequency And Ethylene Oxide, Long Chen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Recent foodborne illness outbreaks in US associated with consumption of low-moisture foods (LMF) have heightened concerns of their microbial safety. Salmonella is a pathogen of major concern in LMF due to its ability to persist in low water activity (a_w) environments. The disadvantages of existing decontamination technologies for LMF call for novel and efficient intervention technologies. Radio frequency (RF) and ethylene oxide (EtO) were evaluated in this dissertation for improving microbial food safety and quality of LMF. Cumin seeds and inshell hazelnuts were selected as model foods.

It took < 2 min of stationary RF heating to achieve > 5 log reductions of Salmonella in cumin seeds without …

Research On Intelligent Hauling Speed Regulation System Based On Shearer's Reliability, Xunan Liu, Lijua Zhao, Dongmin Gai, Zhangyu Du, Liangying Hao

Journal of System Simulation

Abstract: Under the mine, Shearer's hauling speed affected the shearer's efficiency and reliability. Taking MG32570*2/325-BWD shearer as research object, from shearer's reliability, by using Simulink, the intelligent speed regulation system was established, based on shearer key parts' reliability. The building & simulation of hauling motor load torque block and recommended optimum hauling speed generation block which was fitted by neural network was solved. The simulation results show that: this system can achieve the recommended speed, which is traced by hauling speed rapidly and accurately. When consistent coefficient and cutting depth are 2.85 and 0.58m, the hauling motor's maximum speed is …

Multipurpose Image Watermarking Algorithm For Progressive Transmission, Jianqiu Jin, Bangqing Cao, Wang Xun, Haiyan Wu, Bailing Yang

Journal of System Simulation

Abstract: Multipurpose watermarking, which has the property of both robust and semi-fragile watermarking, can realize two or more purposes in one algorithm, e.g. copyright protection and content authentication usually. It can be classified into multi-segment and single-segment watermark embedding. The latter is better in invisibility, but more challenging than the former. A multi-purpose image watermarking algorithm with single-segment watermark embedding for progressive transmission was proposed. It embedded a watermark abstracted from original image into middle and low-frequency coefficients of block DCT transform. In the watermark embedding process, the intensity of watermark could be dynamically adjusted according to the local texture …

Carrier Disposition Pwm Control With No Dead Zone For Tnpc Inverter, Wenjuan Li, Feng Jie, Wang Chao

Journal of System Simulation

Abstract: After the addition of dead zone, the carrier disposition PWM modulation method could have some problems, such as distortion of current waveform and decreasing of voltage utilization ratio. Taking the TNPC type three-level inverter as a researching object, a novel method of the carrier disposition PWM modulation with no dead zone for three-level inverter was proposed, in which three PWM modulation signals were generated by using triple carrier wave. By analyzing the effect caused by the dead zone in different operating states, on and off rules of power switches were derived. Simulation results in MATLAB/Simulink environment show that the …

Roof Material Suitability For It Mission-Critical Facilities, Charles Akira Petrinovich

Theses and Dissertations

Mission-critical facilities house operations that when interrupted, can prove disastrous to an organization’s future. Limited market research is available to determine what roof types are best suited to meet the unique demands of these buildings. The purpose of this research was to evaluate different roof materials and to observe trends relative to their lifecycle costs and roof professional’s assessment in use with mission-critical facilities. The objectives of the study were to determine the average annual lifecycle costs for the sampled roof materials, to determine the roofing professionals’ preferred mission-critical facility roof materials, and to priority rank the sampled roof materials …

Recent Shrinkage And Fragmentation Of Bluegrass Landscape In Kentucky, Bo Tao, Yanjun Yang, Jia Yang, S. Ray Smith, James F. Fox, Alex C. Ruane, Jinze Liu, Wei Ren

Plant and Soil Sciences Faculty Publications

The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is …

Electrochemical Sensors Enhanced By Convection And By 3d Arrays Of Vertically Aligned Carbon Nanotubes, Benjamin James Brownlee

Theses and Dissertations

Early and accessible diagnostics are important elements to reducing the negative side-effects of untreated disease. One key advancement in diagnostic monitoring is through the development of highly sensitive sensors that have the capability to detect lower concentrations, while still remaining accessible for point-of-care use. This dissertation characterizes electrochemical sensing platforms that are enhanced by convection and by 3D electrodes made from high surface area, vertically aligned carbon nanotubes (VACNTs). Free-standing VACNTs were patterned into microchannel arrays for flow-through amperometric sensing. Convective mass transfer enhancement was shown to improve sensor performance in amperometric sensing through the use of high surface area …

Robust Real-Time Model Predictive Control For High Degree Of Freedom Soft Robots, Phillip Edmond Hyatt

Theses and Dissertations

This dissertation is focused on the modeling and robust model-based control of high degree-of-freedom (DoF) systems. While most of the contributions are applicable to any difficult-to-model system, this dissertation focuses specifically on applications to large-scale soft robots because their many joints and pressures constitute a high-DoF system and their inherit softness makes them difficult to model accurately. First a joint-angle estimation and kinematic calibration method for soft robots is developed which is shown to decrease the pose prediction error at the end of a 1.5 m robot arm by about 85\%. A novel dynamic modelling approach which can be evaluated …

Gaussian-Awareness Deep Learning For Block-Level Compressive Video Sensing, Yifei Pei

Computer Science and Engineering Master's Theses

Compressive sensing (CS) is a signal processing framework that effectively recovers a signal from a small number of samples. Traditional compressed sensing algorithms, such as basis pursuit (BP) and orthogonal matching pursuit (OMP) have several drawbacks, such as low reconstruction performance at small compressed sensing rates and high time complexity. Recently, researchers focus on deep learning to get compressive sensing matrix and reconstruction operations collectively. However, they failed to consider sparsity in their neural networks to compressive sensing recovery; thus, the reconstruction performances are still unsatisfied. In this thesis, we use 2D-discrete cosine transform and 2D-discrete wavelet transform to impose …

Motion Reconstruction And Simulation Using Sparse Inertial Sensors, Lijun Cui, Tianyu Huang, Feng Feng, Zhang Jie, Yang Kai, Liu Dong

Journal of System Simulation

Abstract: A method was proposed to reconstruct high-dimensional full-body motion sequences from low-dimensional control data collected by sparse inertial sensors. The approach solved the mapping problem from low dimension to high dimension. A numerical similarity- geometrical similarity-time continuity model was setup to ensure the reconstructed motion candidates in numerical-logical similarity. The gap between angle and angular acceleration was eliminated by acceleration reconstruction. An energy function was introduced to optimize the reconstructed results which guaranteed the accuracy. The analysis and comparison experiments show that the proposed method can reconstruct nature and credible motions in real-time and can be applied …

Business Process Modeling Algorithm Based On Ontology Language, Huang Ying, Kangshun Li, Li Wei, Keqing He

Journal of System Simulation

Abstract: In the view of problem in lack of information sharing mechanisms at the semantic level among processes, a business process modeling algorithm based on ontology language using concept hierarchy as background knowledge was proposed. The business process modeling by traditional business process languages can be transferred to ontology language (OWL) description so as to realize the semantic sharing of business process. The approach has two main advantages compared with traditional methods: (1) accelerating the building process, minimizing the conversion cost; (2) background knowledge guides the extraction of knowledge resided in database. As a way of validating the approach, part …

Measurement Error Correction Model Of Tof Depth Camera, Le Wang, Luo Yu, Haikuan Wang, Minru Fei

Journal of System Simulation

Abstract: 3D data intuitively reflects the full view of the target or scene. Time of Flight (ToF) camera is a range imaging sensor that can provide 3D geometric information of targets immediately, thus it is widely applied in the robot positioning and navigation, 3D reconstruction and other aspects etc. Due to the operational principle of the camera itself, there are variety measurement errors of the source data obtained by ToF, resulting in image distortion. The measurement errors in the imaging process of ToF camera were analyzed and summarized, and the cubic spline interpolation method combined with look-up table was proposed …

Modeling Of Spectrum Sensing Energy Consumption In Cognitive Radio Networks, Ziru Cui, Peng Yi

Journal of System Simulation

Abstract: In cognitive radio networks, the energy consumption in the process of spectrum sensing is the hot spot of research. A unified framework for modeling based on Poisson process was developed which could be used even under interference limited to count the energy consumption, thereby obtaining a spectrum sensing energy consumption. Spectrum sensing energy as the function of the number of secondary users in cognitive radio networks, their spatial density and the number of hops, could be modelled as a truncated gamma distribution. This model is used to statistically analyze cognitive users' energy consumption in the process of spectrum sensing …

Sliding Mode Auto - Disturbance Rejection Control Of Hypersonic Vehicle Under Disturbance, Mingzhi Cheng, Yunjie Wu, Ma Fei

Journal of System Simulation

Abstract: The strong coupling of the hypersonic vehicle, the high order of the model, and the perturbation of the aerodynamic parameters make it difficult for the general controller to achieve the desired control effect. The self-disturbing tandem technique can well meet the requirements of the high-order model control. The use of sliding mode variable structure technology which is not sensitive to perturbation of parameters can enhance the system immunity. The simulation results show that the control effect is very good.

Complexity Analysis Of Joint Operational Network Information System, Peng Jun, Mingzhi Zhang

Journal of System Simulation

Abstract: Based on the theory of complex networks, the structure and characteristics of joint operational network information system (JONIS) were analyzed from the perspectives of heterogeneous directional weighted network topology, strong degree and its centralities. It is found that the combat network based on JONIS has characteristics of small-world and scale-free, with a large average weighted aggregation coefficient and a small average weighted path length, showing a similar power-law distribution. In the example network, command centers, satellites, support force, and early warning unit all have larger strong degrees and centralities. These platforms as the center of gravity and fragile nodes …

Performance Evaluation Method Based On Satisfactory Degree For Air-Information Fusion System, Xiaochao Wu, Li Dong, Zhang Xing, Zhenyu Huang, Liu Bo

Journal of System Simulation

Abstract: Based on the theory of satisfactory degree, a performance evaluation method for air-information fusion system with multi-radar inputs was proposed. According to the designed indexes, the radar deployment and track layout by anti-air warfare, the performance of this fuse system was comprehensively tested with satisfaction method and evaluation software in a simulation testbed. The evaluated results can be the evidences for solving the fusing problem and improving the fusion system combat effectiveness. The effective application of this method in a test shows its value.

Real-Time Modeling Of Interaction Between Floating Objects And Large-Scale Water, Xiaolong Yang, Hongtao Liang, Fengju Kang, Gu Hao

Journal of System Simulation

Abstract: Large scale water is an integral part of nature and of high interest for interactive 3D applications, e.g., computer games and virtual environments. Allowing the water to interact with floating objects is essential for applications, but traditional height field interaction methods concentrate on water-to-body effects by letting water flow through the bodies. A novel GPU-based method for rapid simulation of large scale water interacting with objects was proposed. A specially designed simulation grid was used to solve the interactions between dynamic objects and the surrounding environment. The model of rigid body was realized with a pre-rigid body …

Submarine Tactical Action Scheme Optimization Method Based On Massive Result Data, Zhang Hui, Sijin Wu, Cheng Jian

Journal of System Simulation

Abstract: Taking submarine evasion anti-sub force formation search scheme optimization as an example, a submarine tactical action scheme optimization method based on massive simulation result data was proposed. The operational effectiveness data in different situation of various scheme were generated by off-line simulation, which was used as massive data to support on-line real time decision. Real time decision used interpolation method to estimate the operational effectiveness based on the data. According to the computational experiments, accuracy and efficiency can both satisfy the need of real time decision.

Evolutionary Extreme Learning Machine Optimized By Quantum-Behaved Particle Swarm Optimization, Pang Shan, Xinyi Yang, Xuesen Lin

Journal of System Simulation

Abstract: Extreme Learning Machine (ELM) is a novel learning algorithm for Single-Hidden-Layer Feed Forward Neural Networks (SLFN) with much faster learning speed and better generalization performance than traditional gradient-based learning algorithms. However ELM tends to require more neurons in the hidden layer and lead to ill-conditioned problem due to the random selection of input weights and hidden biases. To address these problems, a learning algorithm was proposed which used quantum-behaved particle swarm optimization (QPSO) to select the optimal network parameters including the number of hidden layer neurons according to the both the root mean square error on validation data set …

Cloud Manufacturing Resource Discovery Method Based On Eav Model And Solr, Geng Chao, Shiyou Qu, Yingying Xiao, Guoqiang Shi, Tingyu Lin, Liqin Guo, Xiaowei Wang

Journal of System Simulation

Abstract: A resource discovery solution of cloud manufacturing based on text information processing technology was proposed. This solution converted the description model of cloud manufacturing resource to a formal model of text information processing via a mapping function, and an EAV (Entity-Attribute-Value) derived model of cloud manufacturing resources was designed to solve the resource properties issues of heterogeneity, diversity, dynamic and so on. By introducing the Solr index schema, the text indexing system of resource properties data was built to improve query performance of related data. A prototype system was designed for discovering cloud manufacturing resources based on …

Dynamics Analysis Of Flue Gas Compression System In Oxy-Coal Fired Boiler, Jianqiang Gao, Zhang Chen

Journal of System Simulation

Abstract: Taking the flue gas compression system in a 300MW oxy-coal fired boiler unit as an object of study by concept design, math model of gas compressor and gas cooler were established with the method of lumped parameter, and dynamic simulation of flue gas compression system was developed. The disturbance experiments on coal-feeder speed and flue gas compressor speed, etc. were carried out based on B-MCR stable condition. As a result, the operating parameters of gas compressor have a more sensitive response and larger change magnitude when the perturbation of coal feeder speed and gas compressor speed is disturbed; when …