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9th International Conference on Advanced Communication Technology (ICACT 2007)

作者： Li Xing-feng Wang Yi-zhi Luo Wan-ming Chinese Acad Sci Comp Network Informat Ctr Beijing 100080 Peoples R China Beijing Jiaotong Univ Sch Comp Sci Infomat Technol Beijing 100044 Peoples R China Grad Univ Chinese Acad Sci Beijing 100039 Peoples R China

ISBN: (纸本)9788955191318

Available bandwidth is an important metric for fast, accurate, and effective estimation of current network conditions. Accurate measurement of the network available bandwidth characteristic has. been an active area for the Internet researchers and telecom operators. Generally, the researchers pay more attention to the end-to-end available bandwidth, while neglecting the study on locating available bandwidth bottleneck. In addition, although there are many existing methods for measuring avail I able bandwidth in IPv4 networks, few of them are related to the next generation Internet. In the last few years, the rapid development and extensive deployment of IPv6 networks make it important to accurately characterize the available bandwidth property of IPv6 networks. This paper proposes an IPv6 networks measurement algorithm for locating available bandwidth bottleneck, which allows end users to efficiently and accurately locate the IPv6 networks bottleneck link. Experimental evaluation shows that our algorithm is accurate, flexible and able to work in uncooperative environments. We are currently experimenting over different network environments to gain more experience, and to further. validate and improve the measurement technique.

关键词： IPv6 locating available bandwidth bottleneck packet train measuring algorithm

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measuring and reconstruction algorithm based on improved second-order generalised integrator configured as a quadrature signal generator and phase locked loop for the three-phase AC signals of independent power generation systems

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IET POWER ELECTRONICS 2016年第11期9卷 2155-2161页

作者： Ke, Chen Wu, Ai Bing, Chen Yi, Liu Huazhong Univ Sci & Technol Sch Mech Sci & Engn Wuhan Peoples R China

In an independent power generation system, the amplitude and frequency of the power generation voltage are easily affected by the fluctuation of the external load and harmonic pollution. The power quality may also be reduced by relatively imprecise measurements. In this regard, a measuring and reconstruction algorithm based on an improved second-order generalised integrator configured as a quadrature signal generator (SOGI-QSG) and phase locked loop (PLL) for three-phase alternating current signals has been proposed in this study. The amplitudes and direct current components of the measured signals are obtained from three SOGI-QSGs. The inverse function of sine is introduced to optimise the phase error that has been used to quickly acquire fundamental frequency and phase of the measured signals. Moreover, the phase sequence of the measured signals is determined by the sign function. Compared with a traditional dual second order generalised integrator PLL, quick responses and reconstruction performances of the proposed algorithm are validated by experiments.

关键词： electric power generation phase locked loops signal generators signal reconstruction power system harmonics integrating circuits measuring algorithm reconstruction algorithm second-order generalised integrator quadrature signal generator phase locked loop three-phase AC signals independent power generation systems power generation voltage external load fluctuation harmonic pollution fluctuation SOGI-QSG PLL sine inverse function fundamental frequency acquisition phase sequence

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An improved high precision measuring method for shaft bending deflection

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APPLIED MATHEMATICAL MODELLING 2017年 48卷 860-869页

作者： Wang, Cong-Hui Pei, Yong-Chen Tan, Qing-Chang Wang, Jia-Wei Jilin Univ Sch Mech Sci & Engn Nanling Campus Changchun 130025 Peoples R China

The circular-section columnar parts, such as shaft, rod and pipe etc., are widely used in all kinds of machines. The bending deformation of such parts will seriously affect the assembly precision and working performance of the machines. A high efficiency and precision measuring method for bending deflection is needed. With a classic contact-detection mechanism at low cost composed of a displacement sensor, a lever and a shaft supporting device, a high precision measuring algorithm is proposed and deduced after strict mathematical analysis in this paper, and which is a closed analytic algorithm and will not produce any principle error. The parameters sensitivity auditing is carried out and the result shows the measuring method has high adaptability. Furthermore, the corresponding experimental calibration method of the current measurement technology is provided, and an experimental validation on the bending deformation of a particular shaft is carried out. The result shows in depth the proposed method has high accuracy. (C) 2017 Elsevier Inc. All rights reserved.

关键词： Shaft bending deflection Eccentricity measuring High precision measuring measuring algorithm Analytic model Experimental verification

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A bending deflection measuring method of inner/outer cylindrical surface parts

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MEASUREMENT 2020年 165卷 108082-108082页

作者： Pei, Yong-Chen Yuan, Yi Li, Hao Wang, Cong-Hui Jilin Univ Sch Mech & Aerosp Engn Nan Ling Campus Changchun 130025 Peoples R China

Inner/outer cylindrical surface parts are often applied into all kinds of machines. The bending deformation of these parts will affect the working performance and service life of the machine. A non-contact measuring method only using a displacement sensor and a guide rail for bending deflection is proposed in this paper. A peak-valley enveloping algorithm derived through rigorous mathematical molding and analysis can be utilized to obtain the eccentricity, direction and the corresponding cross-section position, and then the axis deflection curve can be determined. The error analysis of numerical simulation results shows that the method proposed in this paper can feature a high accuracy by setting appropriate operation parameters. Then, a specialized experiment is carried out to prove the correctness and reliability of the measuring method proposed by comparing with commercial instrument results. Finally, a parameter design method is provided to match the algorithm calculation time and measuring accuracy. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Cylindrical part Inner/outer surface Axial deflection Analytic model measuring algorithm Error analysis Experimental verification

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Research on Optical Microscope measuring Method of External Thread Parameters Based on Charge-couple device

Research on Optical Microscope Measuring Method of External ...

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9th International Conference on History of Mechanical Technology and Mechanical Design (ICHMTMD 2012)

作者： Wang, Wenqi Shao, Dongxiang Jiang, Jianfeng Wang, Guanglin Harbin Inst Technol Sch Mechatron Engn Harbin 150006 Peoples R China China Natl Ctr Qual Supervis & Test Standard Part Zhejiang Peoples R China

ISBN: (纸本)9783037854013

As an important component of the fasteners members, thread's quality, depending on whether its geometric parameters meet requirements or not, will affect the reliability of the whole machine system. Therefore, geometrical parameters measurement of the thread is especially important. Aiming at the characteristics of the thread teeth type, this paper adopt a machine vision measurement method based on the universal tool microscope and CCD This paper also analyzes the causes and influences of the teeth shading and proposes a corresponding improvement method, specific to the shading problem in the process of backlighting projection. After experimenting, this method can effectively improve the accuracy and efficiency of the male parameters measurement.

关键词： Thread parameter Image processing measuring algorithm Teeth shading

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An automatic measuring method and system using a light curtain for the thread profile of a ballscrew

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MEASUREMENT SCIENCE AND TECHNOLOGY 2011年第8期22卷 085106-085106页

作者： Feng, Hu-Tian Wang, Yu-Lin Li, Chun-Mei Tao, Wei-Jun Nanjing Univ Sci & Technol Sch Mech Engn Nanjing Peoples R China

An automatic non-contact measuring system for the thread profile of a ballscrew was developed and integrated using a light curtain, a high-accuracy linear encoder and a motion platform for the measuring stand. Firstly, data points from the thread profile of a ballscrew were collected by the measuring system and data partitioning was performed. Then, the proposed method was used to calculate the most important geometric errors of the thread profile, such as effective diameter, thread pitch, ball track runout and ball track cross-section error. Finally, the proposed system and method was verified for its good performance with acceptable accuracy and reliability. Compared with original measuring methods, the non-contact optical measuring system was capable of measuring most common features of the ballscrew with required accuracy, and was not limited to size and length of the ballscrew.

关键词： ballscrew thread profile light curtain measuring algorithm

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A measurement method for screw rod bending deflection by laser edge detection

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MEASUREMENT 2023年 206卷

作者： Wang, Bin Pei, Yong-Chen Xin, Qing-Yuan Wang, Zhi-Qiong Wang, Lu-Lu Luo, Meng-Yan Jilin Univ Sch Mech & Aerosp Engn Nan ling Campus Changchun 130025 Peoples R China

The bending deflection of screw rod is an essential factor which affects the transmission accuracy and service life of the screw rod. However, existing researches haven't proposed an effective and general method for measuring screw rod bending deflection. In this paper, a novel measurement method is proposed by using a laser edge detection sensor. The screw rod profile is approximated as its outer or inner cylinder by an algorithm based on cubic spline interpolation, and a rigorous mathematical model among eccentricity, initial phase angle and cross-section position is built. Then, extensive numerical simulations are conducted to analyze theoretical errors of proposed method, which provides guiding references for practices. Finally, the feasibility and reliability of proposed method are proved by comparing with measuring projector and repeatability and reproducibility analysis. In conclusion, the proposed method can realize continuous non-contact measurement of screw rod bending deflection and has strong practicability and generality.

关键词： Screw rod Bending deflection Laser edge detection measuring algorithm Numerical simulation Experimental verification

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