The structure of concrete bridge is usually large in dimension and the structural state information is heavily impacted by
many complicated factors. Especially, the influence of temperature to the structural responses is very significant and
this influence varies distinctly with the sun shine, sharp descent of temperature and season changing. Consequently, the
existence of temperature effect will result in a greatly complicated variation of the structural responses, adding great
difficulty in the effective extraction of structural health information for safety assessment of bridges. In this paper, In
order to realize the effective assessment of the structural safety of concrete bridges, according to the correlating
characteristic between temperature and structural response (such as strain or deflection) of the bridge, the experiential
regressive equation is decided by regressive analysis of temperature and structural response, and further more the
temperature effect is separated from the total response. Finally, an application example is given out for demonstration.
The results indicate that the response residual after elimination of temperature effect remains only the effect of
structural variety under loads (including dead load and live load), which can be used as the foundation information for
structural safety assessment of concrete bridges.
This paper proposes a novel Hadamard Transform near-infrared spectrometer based on MOEMS(Optical
micro-electro-mechanical system ) grating light modulator. A new method that grating light modulator combined with a
single near -infrared detector to detect spectrum is applied. The programmability of the grating light modulator linear
array is used to implement a Hadamard Transform encoding masks. Firstly, optics theory has been used to analyze the
essential principle of the spectrometer and the optical principle of grating light modulator. Then, It is theoretically
proved that the Hadamard Transform near-infrared spectrometer can reconstruct spectrum effectively and have a high
signal noise ratio. Finally, a new structure of the grating light modulator is given. Results of the software simulation
show that 5.5V maximum actuating voltage and 5 kHz response frequency are suitable for a miniature, portable,
In the high-precision servo system, not only request quickness but also response characteristics without overshoot, usually
request strong robot for position loop. The traditional control system design usually is finished under the linear condition
which neglects some factors. It makes the more differences between designed model and actual system, so the general PID
adjuster and the single basic fuzzy control are different to meet the need. The paper designs a complex fuzzy controller based
on double structure and variable coefficient, at the same time adopts Cooperative Processing module with fuzzy reasoning
function, which make the system fuzzy reasoning speed improved and realize the online reasoning. So the system capability
is improved, the experiment proved the system has the good capability.
GMLM (Grating Movable Light Modulator)is a novel light modulator based on MOEMS technology which can be used
in fields of display and print. But present design has only 30% effective diffraction area, which can deeply influence the
key parameters such as pixel-filling-ratio and contrast. An electromechanical model of the device was established, and
the effective spring constant of GMLM was deduced by energy method. According to that the relation between structure
parameters and effective diffraction area was analyzed theoretically. Then optimized structures were simulated and
validated by FEM software Coveter Ware. Simulation data shows that the optimization device model can enhance the
effective diffraction area to about 90% from less than 30% before optimization.
In this paper, a 27um×27um novel grating light modulator supported by cantilevers has been presented, and it can be fabricated using silicon surface-micromachining technology. The structure and basic operation principle of grating light modulator is introduced. The structure is composed of grating plate, address electrode and four cantilevers, the grating plate, which is supported by four cantilevers placed around, is overhung about one wavelength of incidence light from the underlying address electrode, it is actuated like a piston by electrostatic force, and piston-type motion of grating can be used to modulate phase of incident light, therefore, the grating light modulator array is a potential device for projection displays and relevant devices for its intrinsic characteristics. Mechanics model is developed for deducing the deformation equation, the relationship between the electromechanical characteristics of the device and the geometrical parameters and material performance is analyzed, such as pull-in voltage, resonance frequency and step response time. Electromechanical coupled simulation is done by Coventorware, then, more reasonable geometrical parameters are obtained for fabricated in the next step.
In this paper, a novel spatial light modulator is presented. A pixel of the novel spatial modulator is turned fully OFF when all pixel ribbons form a flat reflective plane and turned ON by electrostatically deflecting alternate ribbons to produce a blazed diffraction grating. According to scalar diffraction theory, the optical performance is analyzed in details. And the influence factors on diffractive efficiency are discussed. Meanwhile, with the application of electromagnetics, electrodynamics analysis is introduced including the relation between threshold voltage and structure material characteristic. Computer simulation on the condition of different incidence light, different duty-cycle is carried on, presenting the relation between diffraction efficiency and wavelength, duty-cycle, etc. There is a promising foreground based on optimization of structure.
In this paper, the grating light valve (GLV) is presented. A simple method based on multi-beam of light interference theory is put forward to analyze its optical performance. Computer simulation demonstrates that the dimension of its structure and light source have different influence on the diffractive efficiency. According to detecting system, the diffractive efficiency in the OFF state is about 3.8544x10-16 at the wavelength of 0.66um, about 2.8218x10-16at the wavelength of 0.5145um, 1.7846x10-16at the wavelength of 0.488um, which should ideally be zero. The result indicates that such method applied in the analysis of the GLV is agreeable and simpler. In order to gain higher diffractive efficiency, the air gap should be reduced.