scholarly journals Analysis of vibration signal of diamond roller grinding

2021 ◽  
Vol 248 ◽  
pp. 01062
Author(s):  
Yong Liu ◽  
TingBin Fu ◽  
HuaDong Zhao ◽  
ZhenWei Zhu
Keyword(s):  
Correlation Analysis ◽  
Internal Friction ◽  
Machine Tool ◽  
Manufacturing Process ◽  
Low Frequency ◽  
Vibration Signal ◽  
Modal Decomposition ◽  
Non Linear

According to the non-linear and non-stationary characteristics of the vibration signal in the roller grinding manufacturing process, the background signals, namely the vibration signal when the grinder is idling and the vibration signal during contact grinding, are collected separately, and the signal is decomposed into multiple by the method of CEEMDAN modal decomposition. Then several components are removed by correlation analysis. Finally, the signal is denoised and analyzed by wavelet threshold denoising, which lays the foundation for the digital and intelligent grinding of diamond rollers by curve grinders. The results show that most of the grinding noise is in the low frequency, which is mainly caused by the internal friction of the machine tool; the frequency of the grinding vibration signal is mainly distributed around the two frequencies of 250hz and 350hz.

scholarly journals The Experimental Study on Interaction of Vibration and Dynamic Force in Precision Milling Process

2021 ◽  
Author(s):  
Weicheng Guo ◽  
Miaoxian Guo ◽  
Yi Ye ◽  
Xiaohui Jiang ◽  
Chongjun Wu
Keyword(s):  
Machine Tool ◽  
Interaction Effect ◽  
Dynamic Load ◽  
Manufacturing Process ◽  
Wavelet Packet ◽  
Vibration Signal ◽  
Milling Process ◽  
Machining Process ◽  
Dynamic Force ◽  
Coupling Vibration

Abstract A good understanding of the dynamic characteristic in milling of aerospace aluminum, especially the coupling vibration caused by the interaction of the manufacturing process and the machine tool, helps promote the machining precision and surface quality of aerospace structural components. This paper is devoted to proposing the interaction theory of the vibration and dynamic force, which is verified in the milling of Al 7075-T651 by consideration both the machine tool load and machining process dynamic load. First, through detailed analysis of the interaction effect of vibration and the dynamic force, the dynamic milling process is simplified to theoretically model the dynamic interaction in the precision manufacturing process under non-chatter condition. Then, the dynamic process force, which is the key source of the interaction, is modeled and obtained based on wavelet packet transform preprocess; the Frequency Response Function (FRF) of machine tool is regarded as the interaction link between the dynamic force load and the vibration response; the machine tool non-cutting vibration is transformed as a special dynamic load superposed on the response. Finally, the interaction vibration is calculated applying interaction effect model, the predicated results obtained in interaction effect approach match well with the vibration signal directly obtained in the test.

Analysis of Maximum Expiratory Flow Volume Curves Using Canonical Correlation Analysis

1985 ◽  
Vol 24 (02) ◽  
pp. 91-100 ◽  
Author(s):  
W. van Pelt ◽  
Ph. H. Quanjer ◽  
M. E. Wise ◽  
E. van der Burg ◽  
R. van der Lende
Keyword(s):  
Correlation Analysis ◽  
Canonical Correlation Analysis ◽  
Canonical Correlation ◽  
Flow Volume ◽  
Non Linear ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow ◽  
Relationship Of ◽  
The Relationship ◽  
Age And Sex

SummaryAs part of a population study on chronic lung disease in the Netherlands, an investigation is made of the relationship of both age and sex with indices describing the maximum expiratory flow-volume (MEFV) curve. To determine the relationship, non-linear canonical correlation was used as realized in the computer program CANALS, a combination of ordinary canonical correlation analysis (CCA) and non-linear transformations of the variables. This method enhances the generality of the relationship to be found and has the advantage of showing the relative importance of categories or ranges within a variable with respect to that relationship. The above is exemplified by describing the relationship of age and sex with variables concerning respiratory symptoms and smoking habits. The analysis of age and sex with MEFV curve indices shows that non-linear canonical correlation analysis is an efficient tool in analysing size and shape of the MEFV curve and can be used to derive parameters concerning the whole curve.

scholarly journals Non-linear Terahertz driving of plasma waves in layered cuprates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Gabriele ◽  
Mattia Udina ◽  
Lara Benfatto
Keyword(s):  
Low Frequency ◽  
Plasma Waves ◽  
Meissner Effect ◽  
High Energy ◽  
Plasma Mode ◽  
Light Pulses ◽  
High Frequency Plasma ◽  
Non Linear ◽  
Out Of Plane ◽  
Layered Cuprates

AbstractThe hallmark of superconductivity is the rigidity of the quantum-mechanical phase of electrons, responsible for superfluid behavior and Meissner effect. The strength of the phase stiffness is set by the Josephson coupling, which is strongly anisotropic in layered cuprates. So far, THz light pulses have been used to achieve non-linear control of the out-of-plane Josephson plasma mode, whose frequency lies in the THz range. However, the high-energy in-plane plasma mode has been considered insensitive to THz pumping. Here, we show that THz driving of both low-frequency and high-frequency plasma waves is possible via a general two-plasmon excitation mechanism. The anisotropy of the Josephson couplings leads to markedly different thermal effects for the out-of-plane and in-plane response, linking in both cases the emergence of non-linear photonics across Tc to the superfluid stiffness. Our results show that THz light pulses represent a preferential knob to selectively drive phase excitations in unconventional superconductors.

Implementation of MQTT protocol based network architecture for smart factory

2021 ◽  
pp. 095440542110144
Author(s):  
Chia-Shin Yeh ◽  
Shang-Liang Chen ◽  
I-Ching Li
Keyword(s):  
Machine Tool ◽  
Gesture Recognition ◽  
Manufacturing Process ◽  
Network Architecture ◽  
Information Management System ◽  
Edge Computing ◽  
Smart Factory ◽  
Smart Manufacturing ◽  
Industrial Iot ◽  
Computing Module

The core concept of smart manufacturing is based on digitization to construct intelligent production and management in the manufacturing process. By digitizing the production process and connecting all levels from product design to service, the purpose of improving manufacturing efficiency, reducing production cost, enhancing product quality, and optimizing user experience can be achieved. To digitize the manufacturing process, IoT technology will have to be introduced into the manufacturing process to collect and analyze process information. However, one of the most important problems in building the industrial IoT (IIoT) environment is that different industrial network protocols are used for different equipment in factories. Therefore, the information in the manufacturing process may not be easily exchanged and obtained. To solve the above problem, a smart factory network architecture based on MQTT (MQ Telemetry Transport), IoT communication protocol, is proposed in this study, to construct a heterogeneous interface communication bridge between the machine tool, embedded device Raspberry Pi, and website. Finally, the system architecture is implemented and imported into the factory, and a smart manufacturing information management system is developed. The edge computing module is set up beside a three-axis machine tool, and a human-machine interface is built for the user controlling and monitoring. Users can also monitor the system through the dynamically updating website at any time and any place. The function of real-time gesture recognition based on image technology is developed and built on the edge computing module. The gesture recognition results can be transmitted to the machine controller through MQTT, and the machine will execute the corresponding action according to different gestures to achieve human-robot collaboration. The MQTT transmission architecture developed here is validated by the given edge computing application. It can serve as the basis for the construction of the IIoT environment, assist the traditional manufacturing industry to prepare for digitization, and accelerate the practice of smart manufacturing.

Illusory Reversal of Brightness Contrast

1968 ◽  
Vol 27 (3_suppl) ◽  
pp. 1169-1170 ◽  
Author(s):  
Whitman Richards
Keyword(s):  
Visual System ◽  
Visual Angle ◽  
Low Frequency ◽  
Brightness Contrast ◽  
Linear Behavior ◽  
Non Linear

An illusion analogous to Cornsweet's is used to demonstrate how the non-linear behavior of the visual system can be used to obscure low-frequency gradients. The result is a reversal of brightness—from light to dark—as the visual angle of the display is changed.

Shock Test and Acceleration Analysis Methods of Marine Diesel Engines to Underwater Explosions

2013 ◽  
Vol 345 ◽  
pp. 64-67
Author(s):  
Jian Hua Zhao ◽  
Rui Bo Zhang ◽  
De Bin Zhu ◽  
Hong Bin Gao
Keyword(s):  
Diesel Engine ◽  
Low Frequency ◽  
Vibration Signal ◽  
Test Methods ◽  
Shock Acceleration ◽  
Test Results ◽  
Shock Test ◽  
Marine Diesel ◽  
Reduction Methods ◽  
Acceleration Analysis

Shock test of marine diesel engine is the important content for ship anti-shock research. Plentiful shock tests of equipments have been carried out abroad, but there is no detailed test methods of diesel engine. According to simulation results, 8-channel acceleration test points are determined. Because diesel engine is working, the measured shock acceleration is interfered by vibration signal. Orthogonal wavelet decomposition and wavelet noise reduction methods are used to separate shock component from test results. The seperated shock component consists of two parts. One is the low-frequency part caused by the shock from diesel foundation and then attenuation through the isolator, the other is the high-frequency part caused by the secondary shock of the retainer.

Knowledge-Integration Model for Networked Manufacturing

2011 ◽  
Vol 314-316 ◽  
pp. 2027-2032
Author(s):  
Jiao Jian Liu ◽  
Wen He Liao ◽  
Yu Guo ◽  
Wen Bin Wang
Keyword(s):  
Decision Making ◽  
Correlation Analysis ◽  
Knowledge Sharing ◽  
Manufacturing Process ◽  
Knowledge Integration ◽  
Decision Making Process ◽  
Networked Manufacturing ◽  
Optimum Distribution ◽  
Integration Model ◽  
Key Technologies

In order to maximize knowledge sharing and reuse in networked manufacturing process and improve the rapidity and reliability of decision-making, a knowledge-integration model and its implementation methods are proposed in this paper. First, the requirement for knowledge integration in networked manufacturing is analyzed. On this basis, a knowledge-integration model is built, and then three key technologies are studied, namely knowledge representation and organization based on ontology, knowledge correlation analysis based on complex network and knowledge supply based on decision-making context. This model provides an effective way to realize the optimum distribution of knowledge in networked manufacturing process and to improve the efficiency of decision-making process.

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