Precision Generating Cutting Research of Rectangle Spline Based on Parameters Superposition

2011 ◽  
Vol 411 ◽  
pp. 117-120
Author(s):  
Jian Jun Jia ◽  
Hong Xi Wang ◽  
Ling Wang
Keyword(s):  
Simulation Experiment ◽  
Cutting Parameters ◽  
Least Square ◽  
Fusion Method ◽  
Fusion Model ◽  
Design Efficiency ◽  
Least Square Fitting ◽  
Machining Errors ◽  
Spline Shaft ◽  
Cutting Problem

Aiming at the precision generating cutting problem of rectangle spline shaft, the multi-parameter fusion method to modified cutting edge of rectangle spline hob is presented. The method based on the analysis of workpiece machining errors to establish a fusion model about the rectangle spline hob cutting parameters and the rectangle spline shaft deformation quantity, the model can indicate the connection between rectangle spling hob theoretics profile and actual cutting profile, therefore, the rectangle spline hob’s profile is modified and to simulate by polynomials. The simulation experiment indicates that the method exact approximation the hob’s modified profile. Compare with the methods of the double-circular-arc and the least square fitting, the multi-parameter fusion method can enhance both design precision and design efficiency.

An Improved Algorithm of Underwater Target Feature Abstracting Based on Target Azimuth Tendency

2012 ◽  
Vol 155-156 ◽  
pp. 1164-1169
Author(s):  
Yu Xu ◽  
Bing Cheng Yuan ◽  
Hong Gang Zhang
Keyword(s):  
Feature Detection ◽  
Simulation Experiment ◽  
Least Square ◽  
Target Feature ◽  
Least Square Fitting ◽  
Low Snr ◽  
Target Dimension ◽  
Underwater Target ◽  
Detection And Recognition ◽  
Improved Algorithm

Abstracting underwater target azimuth tendency feature is a common method to identify underwater target dimension. The cross-spectrum method of splitting beam is often used to abstracting underwater target azimuth tendency feature. But when the SNR is very low, this method is inefficient. In this thesis, an improved algorithm is presented to abstract underwater target azimuth tendency feature which can be used in the low SNR. In the algorithm, the underwater target highlight structure feature is used, and by least square fitting twice the underwater target azimuth tendency feature will be finally obtained. The simulation experiment results show that the proposed algorithm can be used to abstract underwater target azimuth tendency feature even when the SNR is very low. The improved algorithm has made an important foundation for further studying the feature detection and recognition of an underwater target dimension.

ESTIMATING SURFACE NORMALS IN NOISY POINT CLOUD DATA

2004 ◽  
Vol 14 (04n05) ◽  
pp. 261-276 ◽  
Author(s):  
NILOY J. MITRA ◽  
AN NGUYEN ◽  
LEONIDAS GUIBAS
Keyword(s):  
Point Cloud ◽  
Smooth Surface ◽  
Smooth Curve ◽  
Local Information ◽  
Least Square ◽  
Neighborhood Size ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Normal Estimation ◽  
Least Square Fitting

In this paper we describe and analyze a method based on local least square fitting for estimating the normals at all sample points of a point cloud data (PCD) set, in the presence of noise. We study the effects of neighborhood size, curvature, sampling density, and noise on the normal estimation when the PCD is sampled from a smooth curve in ℝ2or a smooth surface in ℝ3, and noise is added. The analysis allows us to find the optimal neighborhood size using other local information from the PCD. Experimental results are also provided.

scholarly journals COMPARING TWO DIFFERENT MODES OF MECHANICAL VENTILATION BY THE LEAST SQUARE FITTING METHOD: NAVA VERSUS PSV

2015 ◽  
Vol 3 (Suppl 1) ◽  
pp. A319
Author(s):  
S Spadaro ◽  
S Grasso ◽  
V Cricca ◽  
F Dalla Corte ◽  
R Di Mussi ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Least Square ◽  
Least Square Fitting ◽  
Fitting Method ◽  
Least Square Fitting Method

Experimental study on cutting factors of multi-layer machining for large aerospace thin-walled structural parts

2021 ◽  
pp. 095440892110403
Author(s):  
Hangzhuo Yu ◽  
Han Zhong ◽  
Yong Chen ◽  
Lei Lin ◽  
Jing Shi ◽  
...  
Keyword(s):  
Coordinate System ◽  
Experimental Method ◽  
Cutting Parameters ◽  
Machining Process ◽  
Machining Error ◽  
Machining Errors ◽  
Inner Surface ◽  
Thin Walled ◽  
Optimal Cutting Parameters ◽  
Cutting Path

Large aerospace thin-walled structures will produce deformation and vibration in the machining process, which will cause machining error. In this paper, a cutting experimental method based on multi-layer machining is proposed to analyze the influence of cutting tool, cutting path, and cutting parameters on machining error in order to obtain the optimal cutting variables. Firstly, aiming at the situation that the inner surface of the workpiece deviates from the design basis, the laser scanning method is used to obtain the actual shape of the inner surface, and the method of feature alignment is designed to realize the unification of the measurement coordinate system and machining coordinate system. Secondly, a series of cutting experiments are used to obtain the machining errors of wall thickness under different cutting tools, cutting paths, and cutting parameters, and the variation of machining errors is analyzed. Thirdly, a machining error prediction model is established to realize the prediction of machining error, and the multi-objective optimization method is used to optimize the cutting parameters. Finally, a machining test was carried out to validate the proposed cutting experimental method and the optimal cutting parameters.

Digital Fractional Order Savitzky-Golay Differentiator and Its Application

2011 ◽  
Author(s):  
Dali Chen ◽  
Dingyu Xue ◽  
YangQuan Chen
Keyword(s):  
Fractional Order ◽  
Least Square ◽  
One Dimension ◽  
Order Derivative ◽  
Noisy Signal ◽  
Fractional Order Derivative ◽  
Least Square Fitting ◽  
Image Enhancing ◽  
The One ◽  
Derivatives Of

Firstly the one-dimension digital fractional order Savitzky-Golay differentiator (1-D DFOSGD), which generalizes the Savitzky-Golay filter from the integer order to the fractional order, is proposed to estimate the fractional order derivative of the noisy signal. The polynomial least square fitting technology and the Riemann-Liouville fractional order derivative definition are used to ensure robust and accuracy. Experiments demonstrate that 1-D DFOSGD can estimate the fractional order derivatives of both ideal signal and noisy signal accurately. Secondly, the two-dimension DFOSGD is obtained from 1-D DFOSGD by defining a group of direction operators, and a new image enhancing method based on 2-D DFOSGD is presented. Experiments demonstrate that 2-D DFOSGD has very good performance on image enhancement.

Cutting Force Empirical Model of High-Speed Precision Hard Cutting GCr15

2009 ◽  
Vol 69-70 ◽  
pp. 301-305
Author(s):  
Jing Shu Hu ◽  
Yuan Sheng Zhai ◽  
Fu Gang Yan ◽  
Yu Fu Li ◽  
Xian Li Liu
Keyword(s):  
Cutting Force ◽  
Empirical Model ◽  
High Speed ◽  
Orthogonal Design ◽  
Cutting Speed ◽  
Least Square Method ◽  
Cutting Parameters ◽  
Least Square ◽  
Physical Parameters ◽  
Hard Cutting

In the cutting process, cutting force is one of the important physical parameters, which affects the generation of cutting heat, tool life and surface precision of workpiece directly. In this paper an orthogonal design of experiment and subsequent data is analyzed using high speed finish hard cutting GCr15 whose hardness is 65HRC. Cutting speed is 200-400m/min, to study the influence of cutting parameters on cutting force, cutting force empirical model has obtained from least square method.

Estimation of missing components of Fourier Telescopy based on least square fitting

2015 ◽  
Vol 23 (1) ◽  
pp. 282-287
Author(s):  
于树海 YU Shu-hai ◽  
王建立 WANG Jian-li ◽  
董磊 DONG Lei ◽  
刘欣悦 LIU Xin-yue ◽  
王亮 WANG Liang
Keyword(s):  
Least Square ◽  
Least Square Fitting

scholarly journals Indoor Positioning Method Based on Wireless Signal

2018 ◽  
Vol 14 (10) ◽  
pp. 53
Author(s):  
Jingjing Yang ◽  
Zhenyu Feng ◽  
Xuchao Ma ◽  
Xiao Zhang
Keyword(s):  
Measurement Accuracy ◽  
Wave Attenuation ◽  
Indoor Positioning ◽  
Least Square ◽  
Font Size ◽  
Least Square Fitting ◽  
Fitting Algorithm ◽  
Wireless Signal ◽  
Positioning Method ◽  
Indoor Positioning System

<span style="font-family: 'Times New Roman',serif; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-fareast-language: DE; mso-ansi-language: EN-US; mso-bidi-language: AR-SA;">In view of the problems of traditional wireless indoor positioning technologies such as errors and a low positioning accuracy that cannot reach the application level required by hospital indoor positioning, this study proposes a hospital indoor positioning method based on wireless signals. This study firstly analyzes the principles of hospital indoor positioning, verifies the reliability and accuracy of the collected data using Gaussian distribution, P-P plot and Q-Q plot, and finally analyzes the collected data using the least square fitting algorithm to obtain a fitting wave attenuation model, which is then applied to the indoor positioning system. Experiments show that this method can reduce the error of indoor positioning in hospitals, and improve the repeatability and measurement accuracy of indoor positioning in hospitals.</span>

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