Automatic Positioning and Tool Path Planning of Ultra-Large-Scale Components

2010 ◽  
Vol 431-432 ◽  
pp. 277-280
Author(s):  
Jia Feng Wu ◽  
Dong Gao ◽  
Ying Xue Yao
Keyword(s):  
Large Scale ◽  
Tool Path ◽  
Least Square Method ◽  
Tangent Plane ◽  
Optimization Method ◽  
Least Square ◽  
Transformation Theory ◽  
Tool Paths ◽  
Positioning Algorithm ◽  
Automatic Positioning

A method for machining huge workpiece is proposed using coordinate transformation theory. The mathematical model of positioning is derived with nonlinear least square method and solved by iterative algorithm which is given by tangent plane iterative method. Then, initially generated tool paths are modified and optimized. The experiment demonstrates that this method for machining ultra-large-scale workpiece is feasible and correct. The proposed automatic positioning algorithm and tool path optimization method can be used to machine huge workpiece to improve accuracy and reduce cost.

Fast Multipole Virtual Boundary Element - Least Square Method for Solving 2-D Elastic Problems

2011 ◽  
Vol 204-210 ◽  
pp. 2196-2201
Author(s):  
Yan Tao Jiang ◽  
Si Tian Chen ◽  
Cheng Hua Li
Keyword(s):  
Boundary Element ◽  
Large Scale ◽  
Fast Multipole Method ◽  
Main Idea ◽  
Least Square Method ◽  
Least Square ◽  
Fast Multipole ◽  
Large Scale Problems ◽  
Virtual Boundary ◽  
Virtual Boundary Element

In this paper, the fast multipole virtual boundary element - least square method (Fast Multipole VBE - LSM) is proposed and used to simulate 2-D elastic problems, which is based on the fast multipole method (FMM) and virtual boundary element - least square method (VBE - LSM).The main idea of the method is to change computational model by applying the FMM to conventional VBE - LSM. The memory and operations could be reduced to be of linear proportion to the degree of freedom (DOF) and large scale problems could be effectively solved on a common desktop with this method. Numerical results show that this method holds virtues of high feasibility, accuracy and efficiency. Moreover, the idea of this method can be generalized and extended in application.

scholarly journals Linear time-delay circuit and stabilizing controller

2021 ◽  
Vol 2091 (1) ◽  
pp. 012005
Author(s):  
Yuhao Cong ◽  
Yong Zhang ◽  
Guang-Da Hu
Keyword(s):  
Time Delay ◽  
Large Time ◽  
Linear Time ◽  
Least Square Method ◽  
Optimization Method ◽  
Delay System ◽  
Least Square ◽  
Single Chip ◽  
Stabilizing Controller ◽  
Delay Circuit

Abstract This paper is concerned with a linear time-delay circuit and its feedback control. We use electronic components such as resistors and capacitors to realize a linear time-delay system. The time-delays are generated by operational amplifiers and single-chip microcomputers. Based on the actual data measured by the oscilloscope, the parameters of the system are estimated using the least square method. Then a comparison study between the waveform image measured by the oscilloscope and the numerical simulation obtained by MATLAB verifies the effectiveness of the parameters estimations of the circuit system. Furthermore, the circuit system is unstable with a large time-delay, a feedback controller is designed to stabilize the circuit system using the optimization method in the literature. Finally, the experimental results in the linear time-delay circuit show the effectiveness of the optimization method.

Calculation and Optimization of Cutter Position for Flank Milling Spatial Cam Based on NURBS

2008 ◽  
Vol 375-376 ◽  
pp. 578-582
Author(s):  
Rong Yu Ge ◽  
Xian Ying Feng ◽  
Xian Chun Song
Keyword(s):  
Tool Path ◽  
Optimization Method ◽  
Least Square ◽  
Flank Milling ◽  
Normal Vector ◽  
Machining Error ◽  
Cam Mechanism ◽  
Tool Axis ◽  
Milling Method ◽  
Tool Axis Vector

In some cases the spatial cam is manufactured with a cutter whose diameter is smaller than that of the roller of cam mechanism, which is defined as nonequivalent manufacture method in the paper. By the analysis for manufacture of contact lines between the cam and the roller, it is indicated that errors caused by the different directions of normal vector are unavoidable for the nonequivalent manufacture method. In order to find the best tool axis vector to minimize the machining error, this paper realized the nonequivalent machining of spatial cam surfaces using the NC flank milling method and proposed a new generation algorithm of the tool path based on NURBS. The NURBS ruled surface of tool axis trajectory is confirmed based on the least square optimization method and the machining error model is given. At last, a numerical calculation and simulation example is described to verify the effectiveness of the algorithm proposed in the paper.

Novel weights optimization method based on least square method for FPN AND-Rule

2010 ◽  
Vol 24 (7) ◽  
pp. 667-672 ◽  
Author(s):  
Jianxiao Zou ◽  
Houjun Wang ◽  
Jun Shu ◽  
Shicai Fan
Keyword(s):  
Least Square Method ◽  
Optimization Method ◽  
Least Square

Reliability Evaluation on Machining Center Based on Three-Parameter Weibull Distribution

2012 ◽  
Vol 430-432 ◽  
pp. 1645-1649 ◽  
Author(s):  
Gong Chang Ren ◽  
Zhi Wei Yang ◽  
Bo Min Meng
Keyword(s):  
Weibull Distribution ◽  
Goodness Of Fit ◽  
Location Parameter ◽  
Least Square Method ◽  
Optimization Method ◽  
Reliability Evaluation ◽  
Least Square ◽  
Distribution Model ◽  
Adaptive Genetic Algorithm ◽  
Machining Center

In order to improve the model accuracy of reliability evaluation, the Three-Parameter Weibull Distribution model of time between fault was established by introducing location parameters. The correlation coefficient optimization method based on the adaptive genetic algorithm was firstly applied to estimate the location parameter of the Three-Parameter Weibull Distribution. Shape parameter and scale parameter were obtained by the least square method. The time between failures of these series machining center submitting to three-parameter weibull Distribution was checked by the test hypothesis of goodness-of-fit distribution. Finally, the machining center was carried out reliability evaluation based on the Three-Parameter Weibull Distribution model.

A NEW METHOD TO CALCULATE THE MECHANICS PARAMETERS OF SLIP SURFACES

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1558-1563
Author(s):  
Q. SHEN ◽  
J. XU ◽  
C. X. CHEN ◽  
Z. H. YE ◽  
R. WANG
Keyword(s):  
Robust Regression ◽  
Slip Surface ◽  
Back Analysis ◽  
Least Square Method ◽  
Optimization Method ◽  
Least Square ◽  
New Method ◽  
Landslide Stability ◽  
Slip Surfaces ◽  
Site Test

Obtaining the more exact parameters of slip surfaces is proved to be crucial in the analysis of landslide stability, and there are four study methods available i.e. in-site test, laboratory test, back analysis and theoretical analysis. In general, the former two are the basic one, whereas the latter two are secondary. A set of test values about shearing stress and direct stress can be obtained through in-situ and lab tests, then the parameters of slip surface should be calculated to fitting for the test value by the least square method usually, but the effect of anomalous values should increase markedly because the quadratic sum of residual errors is adopted in calculations. In order to reduce the effect of anomalous value, a new method based on the robust regression analysis and the particle swarm optimization method are adopted to calculate the mechanics parameter of landslides in this paper. In the new method, the sum of residual absolute values is used to replace the quadratic sum of residual error, and then the quadratic sum of anomalous value can be avoided. Comparing to the least square method, the new method can reduce availably the effect of abnormal values, and the results are more credible. Furthermore, an engineering example is cited to show the validity.

scholarly journals Optimization Design of an Axial Split-Phase Bearingless Flywheel Machine with Magnetic Sleeve and Pole-Shoe Tooth by RSM and DE Algorithm

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1256 ◽  
Author(s):  
Zhiying Zhu ◽  
Jin Zhu ◽  
Hailang Zhu ◽  
Xi Zhu ◽  
Yajie Yu
Keyword(s):  
Response Surface ◽  
Optimization Design ◽  
Least Square Method ◽  
Basic Structure ◽  
Optimization Method ◽  
Tooth Profile ◽  
Least Square ◽  
Initial Structure ◽  
Element Analysis ◽  
De Algorithm

In order to improve the suspension and torque performance of a bearingless flywheel machine, a new type of axial split-phase bearingless flywheel machine with a magnetic sleeve and pole-shoe tooth is analyzed and optimized as described in this paper. Based on the basic structure and working characteristics of the machine, the response surface methodology (RSM) and differential evolution (DE) algorithm are adopted to further optimize the parameters of the stator teeth of the machine to improve the radial space utilization and motor output performance. Firstly, the Box–Behnken design (BBD) and finite element analysis (FEA) are combined to select the representative optimization parameter combinations to establish the sample data space, and the response surface models of machine torque and suspension force are established using the least square method. Besides this, the DE algorithm is employed to obtain the optimal tooth profile parameter configuration for the multi-objective optimization of machine performance. Finally, the output performances of the machine before and after optimization are compared under initial and optimized winding turns. The results show that, compared with the initial structure, the average torque and suspension force of the optimized machine increase by 36.46 % and 108.22% respectively, which demonstrates the effectiveness of the tooth profile optimization method. At the same time, an experimental prototype is also produced, laying the experimental foundation for further practical exploration.

scholarly journals Regional dynamism between social and commercial ventures

2017 ◽  
Vol 44 (9) ◽  
pp. 1122-1138 ◽  
Author(s):  
Habib Kachlami
Keyword(s):  
Large Scale ◽  
Least Square Method ◽  
Negative Influence ◽  
Positive Influence ◽  
Least Square ◽  
Entry Rate ◽  
Content Type ◽  
The Social ◽  
Social Venture ◽  
Social Ventures

Purpose The purpose of this paper is to study the interaction between social and commercial ventures in a region. It achieves this objective through investigating the influence of social ventures’ entry, exit and density on the entry rate of commercial ventures. Design/methodology/approach Organizational ecology is applied for theoretical analysis and the feasible generalized least square method for empirical analysis. Findings The study, in overall, finds a diffuse competition between the populations of social and commercial ventures. The results have revealed a negative influence of social ventures’ entry and density on the entry rate of commercial ventures and a positive influence of the social ventures’ exit on commercial ventures’ entry rate in a region. Originality/value The study is one of the few in its filed that empirically studies the interaction between social and commercial ventures and the first study, which investigates it in the context of Sweden. The previous two studies, however, have only examined either the influence of social ventures entry or social venture density on the entry rate of commercial ventures. This study, however, examines the influence of both of those factors plus the influence of social venture exit on commercial venture entry. The study is also unique regarding the large-scale database it uses including all the 290 municipalities all over Sweden 1990-2014.

A NEW VIEWPOINT OF S-CURVE REGRESSION MODEL AND ITS APPLICATION TO CONSTRUCTION MANAGEMENT

2006 ◽  
Vol 15 (02) ◽  
pp. 131-142 ◽  
Author(s):  
TING-YA HSIEH ◽  
MORRIS H. L. WANG ◽  
CHENG-WU CHEN ◽  
CHEN-YUAN CHEN ◽  
SHANG-EN YU ◽  
...  
Keyword(s):  
Regression Model ◽  
Large Scale ◽  
Fuzzy Model ◽  
Least Square Method ◽  
Least Square ◽  
City Government ◽  
Fuzzy Regression ◽  
Small Scale ◽  
Project Control ◽  
S Curve

The least square method is in generally used for curve fitting problems. We here propose a fuzzy S-curve regression model to deal with the case in which the observed data are given by fuzzy numbers. The fuzzy regression curve, obtained for project control and predicting the progress of large-scale or small-scale engineering, is smoothly connected by a Takagi-Sugeno (T-S) fuzzy model. This paper also proposes the concept that the upper bound and lower bound are given instead of the confidence interval when the observed data are not obtained exactly. Based on the project cash flow and progress payment records of an example project taken from the Department of Rapid Transit Systems, Taipei City Government, this model is demonstrated and tentative conclusions concerning the model are given. The S-curve equation developed here could be used in a variety of applications related to project control for the management of working capital for construction firms.

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