Study on the Dynamic Active Confocal Probe Based on Time Difference for Surface Measurement

2006 ◽  
Vol 532-533 ◽  
pp. 89-92
Author(s):  
Hong Wei Zhang ◽  
Guo Xiong Zhang ◽  
Yu Ming Fan ◽  
Jia Qin ◽  
Zhi Li ◽  
...  

With the development of modern industry, the consciousness of quality monitoring increases rapidly. The requirements to the dimensional control and profile monitoring of the products including the mechanical, optical and electric ones become higher and higher. New, non-contact and convenient instruments are needed to enable people to evaluate their products. A new type of dynamic active confocal probe is developed in this paper. The key point of this new method is that the displacement measurement of the vibrating lens located on the tuning fork is converted to time difference measurement, which is much simpler and assures higher accuracy in measurement. System structure and improvement, electric circuit and signal processing system are discussed. Experimental studies of the probe performance and analyses of the experimental results are presented.

2011 ◽  
Vol 48-49 ◽  
pp. 924-927 ◽  
Author(s):  
Xiao Yong Zhong ◽  
Xiao Hong Zhang

A new type of steel wire rope non destructive evaluation (NDE) apparatus is presented. It is composed of Hall sensor and signal processing system based on embedded micro processor. The apparatus detects flaws of steel wire rope real-time and on-line. The detection principle, hardware structure and software design of the apparatus are introduced. Examples of the application are given. The experiment results show that quantitatively defect detection of steel wire rope is attained. The apparatus can also be used for the test of the ferromagnetic bars.


Frequenz ◽  
2019 ◽  
Vol 73 (1-2) ◽  
pp. 71-76
Author(s):  
Hongcheng Zhou ◽  
Bing-zhong Wang ◽  
Yu Wang ◽  
Weirong Chen ◽  
Zhongming Yan

Abstract Based on the theory of time reversal technique and through the use of temporal dispersive delay lines, this paper presents a demonstration of temporal cloaked signal transmission at microwave frequencies. When compared with a conventional signal processing system, the related dispersive delay lines are not required to provide linear group delay response. Thus the proposal simplifies the system structure for temporal cloaking, avoids the drawbacks of easy detection, easy decoding and easy analysed brought by linear modulation system, and then strengthen the safety and reliability in signal transmission. Theoretical analysis and experimental results validate the proposed system. The proposed method and achieved results indicate potential application in secure communications and data multiplexing subject to channel bandwidth requirements.


Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 164
Author(s):  
Dongxu Wu ◽  
Fusheng Liang ◽  
Chengwei Kang ◽  
Fengzhou Fang

Optical interferometry plays an important role in the topographical surface measurement and characterization in precision/ultra-precision manufacturing. An appropriate surface reconstruction algorithm is essential in obtaining accurate topography information from the digitized interferograms. However, the performance of a surface reconstruction algorithm in interferometric measurements is influenced by environmental disturbances and system noise. This paper presents a comparative analysis of three algorithms commonly used for coherence envelope detection in vertical scanning interferometry, including the centroid method, fast Fourier transform (FFT), and Hilbert transform (HT). Numerical analysis and experimental studies were carried out to evaluate the performance of different envelope detection algorithms in terms of measurement accuracy, speed, and noise resistance. Step height standards were measured using a developed interferometer and the step profiles were reconstructed by different algorithms. The results show that the centroid method has a higher measurement speed than the FFT and HT methods, but it can only provide acceptable measurement accuracy at a low noise level. The FFT and HT methods outperform the centroid method in terms of noise immunity and measurement accuracy. Even if the FFT and HT methods provide similar measurement accuracy, the HT method has a superior measurement speed compared to the FFT method.


2014 ◽  
Vol 599-601 ◽  
pp. 1407-1410
Author(s):  
Xu Liang ◽  
Ke Ming Wang ◽  
Gui Yu Xin

Comparing with other High-level programming languages, C Sharp (C#) is more efficient in software development. While MATLAB language provides a series of powerful functions of numerical calculation that facilitate adoption of algorithms, which are widely applied in blind source separation (BSS). Combining the advantages of the two languages, this paper presents an implementation of mixed programming and the development of a simplified blind signal processing system. Application results show the system developed by mixed programming is successful.


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