Mini-Nano-Displacement Measurement with Double Diffraction Grating

2011 ◽  
Vol 230-232 ◽  
pp. 1159-1163 ◽  
Author(s):  
Min Lan Jiang ◽  
Fu Peng Li ◽  
Xiao Dong Wang
Keyword(s):  
Diffraction Grating ◽  
Deflection Angle ◽  
Optical Measurement ◽  
Mathematic Model ◽  
Displacement Measurement ◽  
Fourier Optics ◽  
Light Path ◽  
Double Diffraction ◽  
Analysis Method ◽  
Optical Distance

Based on Doppler and Fourier optics analysis method, analyzed the configuration of double diffraction grating, and built its non-contact optical measurement mathematic model. And built double diffraction grating interference displacement measurement system, the design of double diffraction light path can compensate the deflection angle of grating moving, greatly improved tolerance of grating’s deflection. The compact and micro configuration of its light path, shorten optical distance, improving system’s environment anti-interference ability. Experimental resulting show, within 20nm displacement measurement, and<50mm/sec measurement speed, the system resolution is 1nm and measurement precision is less than 30nm.

scholarly journals Static Aeroelastic Characteristics of Morphing Trailing-Edge Wing Using Geometrically Exact Vortex Lattice Method

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Sen Mao ◽  
Changchuan Xie ◽  
Lan Yang ◽  
Chao Yang
Keyword(s):  
Vortex Lattice ◽  
Deflection Angle ◽  
Aircraft Design ◽  
Analysis Method ◽  
Lattice Method ◽  
Trailing Edge ◽  
Vortex Lattice Method ◽  
Analysis And Design ◽  
Aeroelastic Analysis ◽  
Typical Model

A morphing trailing-edge (TE) wing is an important morphing mode in aircraft design. In order to explore the static aeroelastic characteristics of a morphing TE wing, an efficient and feasible method for static aeroelastic analysis has been developed in this paper. A geometrically exact vortex lattice method (VLM) is applied to calculate the aerodynamic forces. Firstly, a typical model of a morphing TE wing is chosen and built which has an active morphing trailing edge driven by a piezoelectric patch. Then, the paper carries out the static aeroelastic analysis of the morphing TE wing and corresponding simulations were carried out. Finally, the analysis results are compared with those of a traditional wing with a rigid trailing edge using the traditional linearized VLM. The results indicate that the geometrically exact VLM can better describe the aerodynamic nonlinearity of a morphing TE wing in consideration of geometrical deformation in aeroelastic analysis. Moreover, out of consideration of the angle of attack, the deflection angle of the trailing edge, among others, the wing system does not show divergence but bifurcation. Consequently, the aeroelastic analysis method proposed in this paper is more applicable to the analysis and design of a morphing TE wing.

A Two-Color Heterodyne Interferometer Based on Diffraction Grating for Displacement Measurement

2005 ◽  
Vol 295-296 ◽  
pp. 189-194 ◽  
Author(s):  
G.H. Wu ◽  
Z.J. Cai ◽  
Li Jiang Zeng
Keyword(s):  
Diffraction Grating ◽  
High Accuracy ◽  
Displacement Measurement ◽  
Optical Diffraction ◽  
Fringe Order ◽  
Heterodyne Interferometer

A two-color heterodyne interferometer based on the movement of the optical diffraction grating is proposed. The method allows us to measure the phase of synthetic wavelength f s directly and with high accuracy to extend the range of unambiguity for interferometric measurements by using two close wavelengths. Our experiment results show that the uncertainty in displacement measurement caused by the uncertainty in f s is 0.20 µm, smaller than the half of a single wavelength we used. The fringe order of a single wavelength can be determined without ambiguity. The uncertainty in displacement measurement can be improved further by using a single wavelength.

Two-degree-of-freedom displacement measurement system based on double diffraction gratings

2016 ◽  
Vol 27 (7) ◽  
pp. 074012 ◽  
Author(s):  
Zhengang Lu ◽  
Peipei Wei ◽  
Chaoqun Wang ◽  
Jialei Jing ◽  
Jiubin Tan ◽  
...  
Keyword(s):  
Measurement System ◽  
Diffraction Gratings ◽  
Degree Of Freedom ◽  
Displacement Measurement ◽  
Double Diffraction ◽  
Two Degree Of Freedom

scholarly journals Stability Analysis of a Direct-Operated Seawater Hydraulic Relief Valve under Deep Sea

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Shan Wu ◽  
Chao Li ◽  
Yipan Deng
Keyword(s):  
Stability Analysis ◽  
Deep Sea ◽  
Great Influence ◽  
Mathematic Model ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Analysis Method ◽  
Relief Valve ◽  
The Stability

Taking into account the deformation of a designed direct-operated seawater hydraulic relief valve in deep sea, which might have a great influence on the stability of the valve, a mathematic model of the relief valve was established and stability analysis was conducted. As the fitting clearances between the damping sleeve and the damping bar play a key role in the performance of the relief valve, the fitting clearances after deformation under pressure of different ocean depths were obtained using finite element method. Applying the deformation data to the relief valve model, the stability and relative stability could be analyzed quantitatively through both the frequency domain analysis method and the time domain analysis method to detect the influence of the fitting clearance after deformation. The simulation results show that the seawater relief valve has a stable performance within 4000 meters deep under the sea.

Six-degree-of-freedom displacement measurement system using a diffraction grating

2000 ◽  
Vol 71 (8) ◽  
pp. 3214-3219 ◽  
Author(s):  
Jong-Ahn Kim ◽  
Kyung-Chan Kim ◽  
Eui Won Bae ◽  
Soohyun Kim ◽  
Yoon Keun Kwak
Keyword(s):  
Measurement System ◽  
Diffraction Grating ◽  
Degree Of Freedom ◽  
Displacement Measurement ◽  
Six Degree Of Freedom
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