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Li B.,Hubei University of Arts and Science | Shi S.,Huazhong University of Science and Technology | Wang S.,DG HUST Manufacturing Engineering Institute
Advanced Materials Research | Year: 2013

A novel image recognition method based on chaotic-particle swarm-optimization-neural network algorithm was presented. The chaotic mapping mechanism and particle swarm algorithm were used to optimize the weight and threshold of BP neural network which was applied to the recognition of image. The simulation results show this new method can overcome the problems that BP neural network is easy to fall into local optimum and sensitive to the initial value, and has better recognition rate and stronger robustness. © (2013) Trans Tech Publications, Switzerland.

Lou Y.,Harbin Institute of Technology | Zhang Y.,Harbin Institute of Technology | Huang R.,Harbin Institute of Technology | Chen X.,Dong - A University | And 2 more authors.
IEEE Transactions on Automation Science and Engineering | Year: 2014

Optimal design is an inevitable step for parallel manipulators. The formulated optimal design problems are generally constrained, nonlinear, multimodal, and even without closed-form analytical expressions. Numerical optimization algorithms are thus applied to solve the problems. However, the optimization algorithms are usually chosen ad arbitrium. This paper aims to provide a guideline to choose algorithms for optimal design problems. Typical algorithms, the sequential quadratic programming (SQP) with multiple initial points, the controlled random search (CRS), the genetic algorithm (GA), the differential evolution (DE), and the particle swarm optimization (PSO), are investigated in detail for their convergence performances by using two canonical design examples, the Delta robot and the Gough-Stewart platform. It is shown that SQP with multiple initial points can be efficient for simple design problems, while DE and PSO perform effectively and steadily for all design problems. CRS can be used to generate good initial points since it exhibits excellent convergence evolution in the starting period. © 2004-2012 IEEE.

Huang Y.,Huazhong University of Science and Technology | Ming W.Y.,Huazhong University of Science and Technology | Guo J.W.,DG HUST Manufacturing Engineering Institute | Li M.Z.,Huazhong University of Science and Technology | Li J.,Huazhong University of Science and Technology
Applied Mechanics and Materials | Year: 2014

As for the high-speed CNC grinding process for non-circular rotary parts with a large rate of lift change (such as camshaft of automotive engine), the acceleration of grinding wheel often has a direct impact on the contour grinding precision of the workpiece due to the large acceleration of movement between of the workpiece and the grinding wheel produced from CNC grinding interpolation. Researches show that solving this problem is an important way to improve the precision of high-speed CNC grinding for non-circular rotary parts. In this paper, a high-speed CNC grinding process control and optimization method is presented for non-circular rotary parts based on acceleration interpolation movement. The negative influence of the problem about high acceleration can be reduced effectively and the precision of high-speed CNC grinding for non-circular rotary parts can be improved greatly by the proposed method. Additionally, the simulation shows that the optimization of grinding parameters forgrinding process has a good performance. © (2014) Trans Tech Publications, Switzerland.

Li Z.,Shenzhen Polytechnic | Lou Y.,Harbin Institute of Technology | Zhang Y.,Harbin Institute of Technology | Liao B.,Harbin Institute of Technology | And 2 more authors.
IEEE Transactions on Automation Science and Engineering | Year: 2013

A novel class of spatial four degree-of-freedom Schönflies-motion parallel manipulators with four identical subchains is presented. Their features are that each serial subchain undergoes the pure Schönflies motion without redundant joints. The parallel mechanisms possess the simplest topology and are suitable for pick-and-place operations. Kinematic analysis of the 4-PRP aR parallel manipulator, including its inverse and forward kinematics, singularity, and workspace, is discussed in detail. The analysis shows that the moving platform and the base must be in dissimilar dimension for good manipulability performance. The optimal design of the parallel manipulator is formulated as a multiobjective optimization problem. A novel performance index characterizing the approximation of the generated workspace to the prescribed regular workspace, the regular workspace share, is proposed to serve as one of the design objectives. The other objective is the global condition index, which measures the manipulability. The multiobjective optimization problem provides multiple optimal solutions for choice. Simulation verifies that the designed parallel manipulator can approximate the prescribed regular workspace with good condition index. © 2012 IEEE.

Li B.,Huazhong University of Science and Technology | Li B.,DG HUST Manufacturing Engineering Institute | Zhang G.-J.,Huazhong University of Science and Technology | Shi S.-X.,Huazhong University of Science and Technology
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2012

Based on the analysis of mold industry characteristics, the problems that uneven distribution of manufacturing resource and capacity seriously had impacted the development of mold industry were pointed out, and existing manufacturing model was difficult to obtain the balance of stability, quality, credit and other aspects in integration of service resource. Aiming at these problems, mould industry cloud manufacturing platform supporting industrial clusters cooperation was proposed. The content of platform was analyzed, and service object as well as application range of platform were illustrated.The system structure and key technologies of platform were discussed. The proposed platform was verified by examples, and it would play an exemplary role for the application of cloud manufacturing in other industries.

Cheng Y.,Huazhong University of Science and Technology | Cheng Y.,DG HUST Manufacturing Engineering Institute | Yang J.,Huazhong University of Science and Technology | Huang Q.,Huazhong University of Science and Technology
2011 International Conference on Consumer Electronics, Communications and Networks, CECNet 2011 - Proceedings | Year: 2011

The performance of motion control on a PMLSM is greatly affected by nonlinearities caused by thrust ripple. The approach of combinational iron-cored primary suggests a thrust ripple-free PMLSM. This paper investigates inductance parameter characteristics and thrust linear modeling of the PMLSM with combinational iron-cored primary. Inductance parameters are derived based on parameters of its armature modular, and symmetric and constant value characteristic of parameters is verified. Based on parameters property of the PMLSM, a thrust linear model is suggested. In comparison with a conventional PMLSM, the PMLSM resolves coupling of inductance parameters between d-axis and q-axis by Parks transformation, and a linear thrust model with a simple lumped parameter is achieved. The validation of the model is verified by simulation of finite-element method. The research predicts that a linear thrust model can be applied to implement a reliable, high efficiency and high performance control of PMLSM. © 2011 IEEE.

Chen Z.,Huazhong University of Science and Technology | Li H.,Huazhong University of Science and Technology | Huang Y.,Huazhong University of Science and Technology | Zhang Z.,DG HUST Manufacturing Engineering Institute
Applied Mechanics and Materials | Year: 2014

In the process of wire electrical discharge machining, the wire electrode inevitably suffers bending deformation due to wire tension, electrostatic force, electrodynamics force, etc., and the deflection would make an clearly negative impact upon the machining accuracy, productivity and stability. In this paper, first of all, a novel modeling and simulation method is proposed for quantitatively calculating the wire deflection. Secondly, the mainly impact factors and trend of wire deflection have been concluded. Moreover, the feasibility of the model is proved by comparing with other researchers models. Eventually, the practical approaches of reducing wire deflection and improving the machining accuracy have been proposed. © (2014) Trans Tech Publications, Switzerland.

Bo L.,Hubei University of Arts and Science | Bo F.,Hubei University of Arts and Science | Li L.,DG HUST Manufacturing Engineering Institute
International Journal of Digital Content Technology and its Applications | Year: 2012

The classical sampling method of radial discrete moments adopts constant point sampling which would lead to too many sampling points in the centre of circle while insufficiency sampling points on the edge of the circle. In order to resolve these problems, the radial Bi-Tchebichef moments are proposed. The proposed moments have two particular properties. Firstly, it projects images in square to images in discrete grids by using Xin's square-to-circular transformation. Secondly, different from classical radial orthogonal vector set, a new discrete orthogonal vector set is constructed by making the discrete Tchebichef polynomials orthogonal in both radial and circumferential direction. Experimental results indicate that the proposed Moments have good performance in image reconstruction and computing efficiency.

Ming W.,Zhengzhou University of Light Industry | Shen D.,Zhengzhou University | Zhang Z.,Huazhong University of Science and Technology | Li H.,Huazhong University of Science and Technology | And 3 more authors.
Journal of Computational Information Systems | Year: 2014

This paper constructs a simulation model, based on a hybrid modeling method combining the two temperature model (TTM) and molecular dynamics simulation (MDS) (TTM-MDS). Parametric studies have been conducted to investigate the relationship between the machining performance, including the melted depth (Dm), the removed depth (Dr) and material removal rate (MRR), and the machining parameters, including pulse-on time and other ones about the input energy for Cu and W material workpiece. Then, comparative analysis of removal mechanism of Cu and W was performed. It can be concluded that it is much harder for W to be removed than Cu, and for Cu, material is removed from the surface in the form of single atoms, while for W, it is mainly in the form of clusters. © 2014 Binary Information Press.

Yang X.,Harbin Institute of Technology | Lou Y.,Harbin Institute of Technology | Li Z.,Hong Kong University of Science and Technology | Li Z.,DG HUST Manufacturing Engineering Institute | Chen H.,Harbin Institute of Technology
Chinese Control Conference, CCC | Year: 2014

Workspace is an important performance index for robotic manipulators. There have been numerous literatures on all aspects of it. This work aims to provide a full picture of workspace. An extensive review of manipulator workspace is presented in this paper, including classification, determination and analysis of workspace. Along with rapid progress of computer's computation performance, the manipulator workspace can be determined efficiently by a simple numerical discretization method, which contributes greatly to fast workspace analysis and design. © 2014 TCCT, CAA.

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