Distortion of removal function based on the local asphericity of aspheric surface and the viscoelasticity of polishing tool in computer-controlled optical surfacing

2017 ◽  
Vol 232 (7) ◽  
pp. 1135-1145 ◽  
Author(s):  
Xianhua Chen ◽  
Bo Zhong ◽  
Jian Wang ◽  
Hongzhong Huang ◽  
Wenhui Deng ◽  
...  
Keyword(s):  
Contact Region ◽  
Influence Factors ◽  
Least Square Method ◽  
Least Square ◽  
Experimental Result ◽  
Aspheric Surface ◽  
Optical Surfaces ◽  
Computer Controlled Optical Surfacing ◽  
Computer Controlled ◽  
Polishing Tool

In the process of large aspheric optical surfaces fabrication, the distortion of the removal function is a big problem that affects the producing efficiency and accuracy, due to the misfit between the tool and the aspheric surface in the contact region. Consequently, this paper aims to find out the influence factors and the distortion rule of aspheric removal function in the computer-controlled optical surfacing. Firstly, based on the analysis of the sub-aperture polishing technology for the large aspheric optical surfaces, the local asphericity of aspheric surface and the viscoelasticity of polishing tool are supposed to be the main sources. After that, a method to calculate the local asphericity considering the misfit between the tool and the aspheric surface is proposed based on the least square method, and the viscoelasticity of the polishing tool is obtained through viscoelastic experiment. Subsequently, combining the results of the local asphericity of aspheric surface and the viscoelasticity of polishing tool, the prediction of the distortion rule of aspheric removal function is presented. Finally, the comparative experiment is carried out, and the removal function on different regions of the aspheric surface is obtained. The experimental result indicated that the distortion of the removal function is consistent with the theoretical result. Through this study, the distortion rule of aspheric removal function in the computer-controlled optical surfacing with pitch tool is finally mastered, which provides a theoretical guidance for the computer-controlled optical surfacing process optimization.

Fundamental Investigation on the Polishing Aspheric Elements with Doughnut-Shaped MCF Slurry

2018 ◽  
Vol 792 ◽  
pp. 179-184 ◽  
Author(s):  
Ming Feng ◽  
Yong Bo Wu ◽  
Teruo Bitoh ◽  
Tsunehisa Suzuki ◽  
Mitsuyoshi Nomura ◽  
...  
Keyword(s):  
Experimental Result ◽  
Aspheric Surface ◽  
Aspheric Surfaces ◽  
Variable Parameters ◽  
Flat Surfaces ◽  
Surface Polishing ◽  
Fundamental Investigation ◽  
Novel Method ◽  
Curve Radius ◽  
Polishing Tool

Previous researches have confirmed that MCF (magnetic compound fluid) slurry shows outstanding performance in the nanoprecision polishing of flat surfaces and V-grooves. However, no investigations have been conducted on the polishing of aspheric surfaces using MCF slurry. In this work, a novel method employing a doughnut-shaped MCF polishing tool and a 6-DOF manipulator has been proposed for the aspheric surface polishing. The time consumption for forming stable polishing tool and its final appearance are investigated. Flat aluminum alloy workpieces that can be considered as a kind of aspheric elements with infinite curve radius were adopted in the investigation of the polished forces under variable parameters. As a typical experimental result, with MCF3 slurry, 2.5ml volume of supplied slurry and work gap 3.5 mm, the surface roughness Ra decreases from 125nm to almost 10nm after 90 min polishing, confirming that the proposed method has the potential to polish aspheric surfaces.

The Boiler Temperature Field Reconstruction Algorithm Based on Genetic Algorithm

2011 ◽  
Vol 88-89 ◽  
pp. 269-273
Author(s):  
Cheng Zhi Li ◽  
Fu Qun Shao ◽  
Zhe Kan ◽  
Hai Xiang Fan
Keyword(s):  
Genetic Algorithm ◽  
Temperature Field ◽  
Least Square Method ◽  
Reconstruction Algorithm ◽  
Acoustic Method ◽  
Least Square ◽  
Experimental Result ◽  
Field Reconstruction ◽  
Single Path ◽  
Temperature Field Reconstruction

The traditional power station boiler temperature field reconstruction algorithm is sensitive to the time of flight. In the boiler movement, the temperature field has symmetric distribution feature within the boiler. On the basis of the boiler temperature field reconstruction fundamental by using the acoustic method, the paper presents a new two dimension temperature field reconstruction algorithm, which combines the single path method and genetic algorithm. Firstly, the algorithm makes sure the temperature distribution by using single path function. It uses the points denote the temperatures on each path, and plots the mesh, which can represent the temperature preliminary distribution, by using the Bezier spline principle and linear multistep integration. Finally, the surface mesh is Interpolated and fitted by using genetic algorithm. The experimental result proved that, compared to the least square method, the new reconstruction algorithm has the feature of higher accuracy and higher reconstruction speed.

Mathematical Model and Simulation for Testing Aspheric Surface Using the Digital Moiré Patterns by Circular Sub-Region Stitching Method

2014 ◽  
Vol 945-949 ◽  
pp. 2097-2101
Author(s):  
Yu Chun Man ◽  
Chun Yuan Zhou
Keyword(s):  
Mathematical Model ◽  
Simulation Experiment ◽  
Phase Distribution ◽  
Least Square Method ◽  
Least Square ◽  
Phase Shifting ◽  
Aspheric Surface ◽  
Model And Simulation ◽  
Computer Simulation Experiment ◽  
Digital Moiré

sub-region stitching measurement of asphere by using the combination of digital moire patterns without compensator, auxiliary mirror and other assistant modules. This paper illustrated the principal theory. And use of digital filtering, phase shifting, the least square method and Zernike polynomial fitting to establish the reasonable mathematical model. Meanwhile the computer simulation experiment was carried on. the PV and RMS of the full aperture phase distribution residual error are 0.058λand 0.0087λ After this method processing.

Study on Prediction Models of Milling Force for T10 Hardened Steel

2011 ◽  
Vol 175 ◽  
pp. 342-346
Author(s):  
Jing Quan Wu ◽  
Guang Hui Li ◽  
Can Liu ◽  
Guang Yu Tan
Keyword(s):  
High Speed ◽  
Prediction Models ◽  
Least Square Method ◽  
Cutting Parameters ◽  
Hardened Steel ◽  
Least Square ◽  
Experimental Result ◽  
Force Curve ◽  
Milling Force ◽  
Set Up

To represent the relation between force and cutting parameters in milling T10 hardened steel, single factor milling experiments with different cutting parameters were done. The experimental result showed that there exited maximum inflection point in force curve under different speeds, and the relation between force and cutting parameters could not be represented with an uniform mathmatical equation. Respective prediction modal of milling force in low speed and high speed were set up using least-square method, which was significant at level of α=0.0005, and its result of R- test was higher than 0.98. This study indicates that the applicable prediction modals in milling T10 steel with low and high speed are different, predict modals being set up can be used to estimate milling force.

A New Method to Model Spherical Roller Bearings due to Self-Aligning Feature

2015 ◽  
Author(s):  
Yu Xing ◽  
Hua Xu ◽  
Shiyuan Pei ◽  
Xuejing Liu ◽  
Fengcai Wang
Keyword(s):  
Contact Region ◽  
Linear Equations ◽  
Least Square Method ◽  
Least Square ◽  
Hertzian Contact ◽  
Design Parameters ◽  
Roller Bearings ◽  
Proposed Model ◽  
Computing Procedure ◽  
Maximum Contact

This research presents an analytical model to describe the indeterminate contact status and analyze the loaded condition, then acquire the key design parameters so as to improve the carrying capacity of spherical roller bearings. The model based on the non-Hertzian contact theory is applied to reflect the indeterminate contact status due to the self-aligning feature. The loaded condition, which is including the load distribution, the size of the contact region and the maximum contact pressure, is calculated according to the force analysis of spherical roller bearings. The non-linear equations are solved by using secant method and the proposed model is validated by comparing with the published reference. The importance of the indeterminate contact status is illustrated by comparing with the computing results of the Hertzian contact model. The fitted method based on the least square method is used to obtain the equivalent stiffness and the load-deformation exponent, whereby the computing procedure is simplified. In view of the operating condition and the lubricated effect, properly increasing the osculation number or the number of the rollers will obviously improve the carrying ability of spherical roller bearings.

Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.

PENGARUH KNOWLEDGE MANAGEMENT, KOMPETENSI, MOTIVASI TERHADAP KINERJA KARYAWAN

2015 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Miftahol Arifin
Keyword(s):  
Knowledge Management ◽  
Linear Regression ◽  
Significant Influence ◽  
Employee Performance ◽  
Least Square Method ◽  
Least Square ◽  
Analysis Tool ◽  
Ordinary Least Square ◽  
Competence Motivation ◽  
Performance Analyze

The purpose of this research is to analyze the influence of knowledge management on employee performance, analyze the effect of competence on employee performance, analyze the influence of motivation on employee performance). In this study, samples taken are structural employees PT.centris Kingdom Taxi Yogyakarta. The analysis tool in this study using multiple linear regression with Ordinary Least Square method (OLS). The conclusion of this study showed that the variables of knowledge management has a significant influence on employee performance, competence variables have an influence on employee performance, motivation variables have an influence on employee performance, The analysis showed that the variables of knowledge management, competence, motivation on employee performance.Keywords: knowledge management, competence, motivation, employee performance.

Peristaltic Carreau-Yasuda nanofluid flow and mixed heat transfer analysis in an asymmetric vertical and tapered wavy wall channel

2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  
Keyword(s):  
Heat Transfer ◽  
Least Square Method ◽  
Weissenberg Number ◽  
Least Square ◽  
Heat Transfer Analysis ◽  
Phase Method ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Nanoparticles Concentration ◽  
The Right

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.

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