A 3D laser scanning system for rock surface measurement was developed based on structured light measuring technique.
The structure of the system was designed. A fast calibration method for the 3D laser scanning system was presented in
detail. After the system was calibrated, the measuring precision was verified in the depth direction. Experimental results
proved that the measuring precision of the system is better than 0.02mm. And the system can achieve high performance
during practical application.
The UV absorption spectrometry technique DOAS (Differential Optical Absorption Spectroscopy) has been widely used
in continuous monitoring of flue gas, and has achieved good results. DOAS method is based on the basic law of light
absorption--Lambert-Beer law. SO2, NOX are the principal component of the flue gas. These components are
considered by DOAS method at the same time. And certain mathematical methods are used for concentrations
measuring. The Continuous Emission Monitoring System (CEMS) based on the principle of DOAS mainly has two
probe-styles present: in-situ probe-style and extractive probe-style.
For the in-situ probe-style CEMS based on DOAS method, prolonged use for the UV light source, contaminated lens
caused by floating oil and complex environment of the flue will all bring attenuation of the spectral intensity, it will
affect the accuracy of measurement. In this article, an in-situ continuous monitoring system based on DOAS method is
described, and a component adaptive sensing technology is proposed. By using this adaptive sensing technology, CEMS
can adjust the integral time of the spectrometer according to the non-measuring attenuation of the light source intensity
and automatically compensate the loss of spectral intensity. Under the laboratory conditions, the experiments for SO2,
NO standard gas measurement using adaptive sensing technology is made. Many different levels of light intensity
attenuation are considered in the experiments. The results show that the adaptive sensing technology can well
compensate the non-measuring loss of spectral intensity. In the field measurement, this technology can well reduce the
measurement error brought by attenuation of light intensity, compared with the handheld gas analyzer, the average error
of concentration measurement is less than 2% FS(Full Scale).
The measuring principle of SO2 and NOx, which are the main gaseous contaminants in flue gas, is given based on the
differential optical absorption spectroscopy (DOAS). And the structure and composition of the measurement system are
introduced. In the aspect of obtaining the absorption feature of measured gas, a multi-resolution preprocessing method of
original spectrum is adopted to denoise by the signal energy in different scales. On the other hand, the useful signal
component is enhanced according to the signal correlation. These two procedures can improve the signal-noise ratio
(SNR) effectively. In addition, the origin of the nonlinear factors is analyzed, that is caused by the actual measurement
condition. And the polynomial approximation equation is deduced. In the lab, SO2 and NO are measured several times
with the system using the data extraction method mentioned above. The average deviation is less than 1.5%, while the
repeatability is less than 1%. In the scene of one power plant whose concentration of flue gas has a large variation range,
the maximum deviation is 2.31% in the 18 groups contrast data.
KEYWORDS: 3D metrology, Calibration, Laser welding, 3D image processing, Laser applications, CCD cameras, 3D acquisition, Image processing, Control systems, Semiconductors
A 3D measurement system of solder pastes was established. The system aims to extract the height and other values of
solder paste, and realize the quality control of Surface Mount Technology (SMT). 3D laser measurement technique was
applied to this system. The calibration process is divided into two steps, the internal parameters of CCD camera are
obtained by the RAC method of Tsai, and the laser plane parameters are calibrated with one special multi-arris block.
The scanning technique fulfills the acquisition of final 3D profile. Experimental results at the product line prove that the
system is a more easily operated device with high performance, and its repeatable precision reaches ±1 µm.
This paper proposes a new static routing algorithm applying Traffic Engineering, which integrates Multiprotocol Label Switching (MPLS) and Quality of Service (QoS) Routing. Because of using MPLS, centralized control is applied to the transmission paths of different service type in the algorithm. At the same time, to select LSP based on the state of networks and the requirements of QoS, the algorithm can make the resource using globally optimal. It avoids the traditional routings’ shortage that the network congestion is produced by the disequilibrium of resource using. United object strategic in the algorithm can produce effective projects for the problem of satisfying Multi-requirement in one routing count, which is NP-hard. Finally the paper proves that the algorithm is feasible and preferable by computer simulation and theoretical deduction.
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