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1.
Hongzhuang ZHANG Ping ZENG Shunming HUA Guangming CHENG Zhigang YANG 《Frontiers of Mechanical Engineering in China》2008,3(1):71-75
An impact drive rotary precision actuator with end-loaded piezoelectric cantilever bimorphs is proposed. According to finite
element analysis and experiments of the dynamic characteristics of end-loaded piezoelectric cantilever bimorphs, a specific
fixed-frequency and adjustable-amplitude is confirmed to control the actuator. The results show that an actuator excited by
fixed-frequency and the adjustable-amplitude ramp voltage waveform works with a large travel range (180°), high resolution
(1 μrad), speed (0.2 rad/min) and heavy-load ability (0.02 Nm). With advantages of high-precision positioning ability, simple
structure and only one percent the cost of traditional impact drive mechanisms, the actuator is expected to be widely used
in precision industries.
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Translated from Optics and Precision Engineering, 2005, 13(3): 298–304 [译自: 光学精密工程] 相似文献
2.
Liu Jianfang Yang Zhigang Zhao Hongwei Cheng Guangming 《Frontiers of Mechanical Engineering in China》2007,2(3):356-360
A novel piezoelectric (PZT) precision step rotary actuator was developed on the basis of PZT technology. It adopts the principle
of bionics and works with an inside anchoring/loosening of the stator and a distortion structure of the uniformly distributed
thin flexible hinge to solve problems such as ineffective anchoring/loosening, low step rotary frequency, small travel, poor
resolution, low speed and unsteady output. The developed actuator is characterized by high frequency (30 Hz), high speed (380
μrad/s), large travel (>270°), high resolution (1 μrad/step), and work stability. It greatly improves the ability to drive
the existing PZT step rotary actuator. The new actuator can be applied in the field of micromanipulation and precision engineering,
including precision driving and positioning and optics engineering.
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Translated From
Journal of Jilin University (Engineering and Technology Edition), 2006, 36(5): 673–677 [译自: 吉林大学学报 (工学版)] 相似文献
3.
S. A. Batishche A. A. Kouzmouk G. A. Tatur 《Instruments and Experimental Techniques》2011,54(1):114-117
An optical scheme and design of a YAG:Nd3+ frequency laser with a two-pass amplifier and a mirror with the phase conjugation by the stimulated Brillouin scattering
in an optical fiber is described. The maximal radiation energy is 1000 mJ at a 1.064-μm fundamental wavelength and 500, 200,
and 20 mJ at the second, fourth, and fifth harmonics, respectively, when the divergence is ∼5 × 10−4 rad and the pulse duration is 4.5 ns. 相似文献
4.
This paper presents an experimental study correlating frictional behavior with in situ voltammetry for a unidirectional sliding
contact between a hemispherical tipped alumina probe and a flat rotating copper counterface (maximum Hertzian contact pressure
of 68 MPa and sliding speed of 10 mm/s). The contact was immersed in an aqueous 0.1 M Na2CO3 solution (pH ∼11) where the copper counterface acted as the working electrode in a potentiostat controlled three-electrode
cell; a coiled Pt wire was used as the counter electrode and a saturated calomel electrode (SCE) as the reference. Clear and
reproducible trends were found between friction coefficient and published data suggesting the onset of particular redox reactions,
graphically presented in a frictional voltammetry plot. At anodic potentials primarily associated with the formation of copper(I)
oxide (Cu2O) (V vs SCE ∼−0.25), the measured friction coefficient was in the range μ ∼0.4–0.5. At cathodic potentials primarily associated
with the formation of CuO, Cu(OH)2, and CuCO3 (V vs SCE ∼−0.10), the friction coefficient transitions to the range μ ∼0.7–1.0. At sustained cathodic potentials associated
with reduction of the native copper oxide, Cu2O, (V vs SCE ∼−0.65), the friction coefficient is observed to fluctuate between μ ∼0.2 and 0.5, arguably a result of exposure
of bare copper due to non-uniform reduction (fractional coverage) of Cu2O. 相似文献
5.
Dong-Weon Lee 《Journal of Mechanical Science and Technology》2005,19(11):2172-2178
We describe a cantilever device for a novel ’Time-Of-Flight Scanning Force Microscope (TOF-SFM)’ concept that has the capability
of chemical analysis. The cantilever device consists of a switchable cantilever (SC), a microfabricated extraction electrode,
and a LEGO-type microstage, which combines two different systems. It allows quasi-simultaneous topographical and chemical
imaging of a sample surface to be performed in the same way as with conventional scanning probe techniques. This is achieved
by the micromachined SC with a bimorph actuator that provides a reasonable switching speed in comparison with mechanically
operated switches. Secondly, a short tip-electrode distance to minimize the ions extraction voltage can be realized by LEGO-type
microfabrication. The measured SC tip deflection is -100 μm at 35 mW, corresponding to an estimated heater temperature of
-250°C. The maximum switching speed between the two modes is -10 msec, and the sensitivity ΔR/R of an integrated piezoresistive deflection sensor is -6.7× 10-7/nm. The tip-electrode distance is only 10 μm. The TOF-SFM is currently integrated in an ultra-high-vacuum system to perform
several measurements. 相似文献
6.
自由空间光通信ATP系统中精瞄偏转镜的设计 总被引:4,自引:9,他引:4
二维精瞄偏转镜是自由空间光通信中捕获、跟踪和瞄准(ATP)系统的关键组成部分,对偏转镜进行了机构设计和有限元模态分析,偏转镜采用压电陶瓷驱动器驱动,采用柔性铰链传动。研制了集驱动、检测、主控模块为一体的数字式精密定位控制器,在实验室构建了两套测试系统,对偏转镜的频率和静态性能进行了测试,并着重介绍了频率的两种测量方法及其优缺点分析。仿真和测试结果表明,偏转镜的频率约为1.5 kHz,转角范围约为±2 mrad,精度约为1 μrad,分辨率约为0.1 μrad。 相似文献
7.
In this paper, auto focus actuator, which is used to move a lens module in the mobile phone having a camera module, is developed.
Camera module containing auto focus actuator requires to minimize total size because of characteristics of the application
area such as mobile phone, digital camera, and personal digital assistant. There are stepping motor, voice coil motor, and
piezoelectric motor as auto focus actuator. In this paper, voice coil motor having new electromagnetic configuration is proposed.
And actuator using proposed voice coil motor is developed by optimal design method using magnetic circuit analysis. The sectional
area of the developed actuator is reduced to 32.4% compared with actuator using general electromagnetic configuration. From
the performance test, the developed actuator has moving stroke of 0.64 mm for 2.1 volt, hysteresis of 40 μm, full stroke current
of 54 mA, and unit step motion of 3 μm. 相似文献
8.
Won-Shik Chu Chang-Il Beak Sung-Hoon Ahn Tae-Hwan Cho 《Journal of Mechanical Science and Technology》2006,20(1):85-93
The trend of miniaturization has been applied to the research of rockets to develop prototypes of micro rockets. In this paper,
the development of a web-integrated prototyping system for three-dimensional micro rockets, and the results of combustion
tests are discussed. The body of rocket was made of 6061 aluminum cylinder by lathe process. The three-dimensional micro nozzles
were fabricated on the same aluminum by using micro endmills with φ100μm~φ500 μm diameter. Two types of micro nozzle were
fabricated and compared for performance. The total mass of the rockets was 7.32 g and that of propellant (gun powder) was
0.65 g. The thrust-to-weight ratio was between 1.58 and 1.74, and the flight test with 45 degree launch angle from the ground
resulted in 46 m~53 m of horizontal flight distance. In addition, ABS housing for the micro machined rocket was fabricated
using Fused Deposition Modeling (FDM). A web-based design, fabrication, and test system for micro nozzles was proposed to
integrate the distributed hardware resources. Test data was sent to the designer via the same web server for the faster feedback
to the rocket designer. 相似文献
9.
A microlateral force sensor (MLFS) was developed and evaluated using atomic force microscopy (AFM). The sensor was attached to a sensing table supported by a suspension system. The lateral motion of the sensing table was activated by a comb actuator. The driving voltage to the comb actuator was controlled to maintain a constant position of the sensing table by detecting the tunneling current at a detector, which consisted of two electrodes where the bias voltage was applied. An AFM was used to apply a lateral force to the sensing table of the sensor. When the probe of a cantilever was pressed against the sensing table and a raster scanning was conducted, the driving voltage of the comb actuator changed to compensate the friction force between the probe and sensing table. AFM measurements of an asperity array on the sensing table were conducted, and a lateral force microscopy image (LFM) was obtained from the change in driving voltage. The image by MLFS was very similar to the LFM image that was conventionally obtained from torsion of the cantilever. The LFM image strongly correlated with the gradient image calculated from the AFM topographic image. The force sensitivity of the MLFS was determined by comparing the LFM image obtained by using the MLFS with the tangential force derived from the gradient of the AFM image. 相似文献
10.
I. D. Kostyrya D. V. Rybka V. F. Tarasenko 《Instruments and Experimental Techniques》2012,55(1):72-77
The results of experimental studies of the parameters (amplitude and duration) of a supershort avalanche electron beam (SAEB)
generated in air at atmospheric pressure are presented. It is shown that the pulse duration of the beam current behind the
foil from the entire area of the anode foil is larger than from small areas and depends on the cathode design. The number
of electrons that are detected behind the 10-μm-thick Al foil is ∼6 × 1010 electrons, which corresponds to a SAEB amplitude of ∼100 A at a FWHM of the current pulse of ∼100 ps. An X-ray exposure dose
per pulse of ∼1.8 mR was obtained using a 20-μm-thick copper foil. It was confirmed that the FWHM of a SAEB pulse is within
∼50 ps from small foil areas (with diameters of ∼7 mm or smaller). 相似文献
11.
The current of positive ions in a liquid-xenon ionization chamber was studied under intense pulsed irradiation of the chamber
with bremsstrahlung from a microtron. The dose absorbed in xenon during a radiation pulse was varied from 0.1 to 1.3 × 104 μGy. It has been revealed that, in the dependence of the current on the irradiation dose, a deviation from a simple linear
dependence is observed at a pulse dose of ∼4 μGy (∼0.2D
cr). Calculations show that recombination is the main cause of such deviation. A space charge appearing in the chamber under
high irradiation intensities leads to a decrease in the electric field. The manifestation of the effects of a space charge
becomes substantial when the field in a certain part of the chamber drops almost to zero. Under particular irradiation conditions,
the space charge manifested itself in this study beginning with doses in a pulse of ∼50 μGy. The joint effect of the recombination
and the space charge resulted in a dependence of the type of i ∼ D
1/3. The influence of the ion current on the energy resolution of the ionization spectrometer is calculated for γ quanta detected
during intervals between irradiation pulses. It is shown that a substantial impairment of the resolution begins at doses appreciably
lower than the critical dose. The influence of the ion current becomes greater, as the dimensions of the chamber increase. 相似文献
12.
R. O. Buzhinskii K. I. Zemskov A. A. Isaev A. V. Vlasov V. G. Ral’chenko V. V. Savranskii 《Instruments and Experimental Techniques》2010,53(2):301-304
The chemical vapor deposition (CVD) technique is applied for synthesizing diamond films and plates of large size (∼100 mm)
and high quality. In the given work, we consider one of the diamond-structure dimensional processing and microprocessing methods
based on the application of a Cu laser, whose irradiation can be focused to a small spot and also used for the intensification
of the image brightness in an optical system, which is able to process ∼106 points of an object for one (∼10 ns) or a few pulses. The characteristics of processed surfaces of polycrystalline diamond
films and plates are given. 相似文献
13.
This paper develops a 30 mm × 30 mm × 50 mm spherical micro actuator driven by piezoelectric ceramic stacks (PZT), and analyzes
its dynamic performances. First, the space coordinate relationship of the spherical micro actuator and a dynamic model are
set up. Second, The Runge-Kutta arithmetic is used to calculate the dynamical parameters of the micro actuator; the SIMULINK
module of MATLAB is used to build the dynamical simulating model and then simulate it. Third, an experimental sample of the
spherical micro actuator is developed, a micromanipulator is integrated with a micro-gripper based on the sample spherical
micro actuator, and the experimental research on the micro assembly is conducted between a micro shaft of Φ180 μm and a micro spindle sleeve of Φ200 μm. Finally, the characteristics of the spherical micro actuator influenced by the mass of the metal sphere of the micro
actuator, driving signal frequency, friction coefficient of the contact surface between the metal sphere and the friction
block of the micro driving unit are analyzed. The experimental results indicate that the rotation resolution of the micro
actuator reaches 0.000 1°, the rotation positioning precision reaches 0.000 5°, and the maximum working frequency is about
1200 Hz. The experimental results validate the back rotation vibration model of the spherical micro actuator. The micromanipulator
integrated by the spherical micro actuator can meet the requirements of precise micro operation and assembly for micro electro
mechanical systems (MEMS) or other microelements in micro degree fields.
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Translated from Optics and Precision Engineering, 2007, 15(2): 248–253 [译自: 光学精密工程] 相似文献
14.
为解决角锥棱镜失偏效应,提出一种外加晶片的椭圆偏振光纠偏方案。总结角锥实棱倾斜时的修正公式,同时建立角锥在顺、逆时针反射次序下的纠偏模型。分析该模型表明利用两个半波片和一个延迟片可以使角锥的入/出射偏振态保持不变。根据上述模型,用1 064 nm波长的激光器,对实棱线竖直摆放的BK7玻璃角锥进行顺、逆时针纠偏实验。光波矢与水平方向的夹角在90°至0°之间变化,以获得不同的线偏振态,经纠偏后最大失偏椭圆率绝对值从35°纠正为5°。对于近圆偏振光,经纠偏后椭圆率从44°下降到40°。 相似文献
15.
Young-Sup Lee 《Journal of Mechanical Science and Technology》2011,25(1):61-68
Some possible collocation strategies of sensor and actuator pairs for the application to active vibration control systems
are analyzed, compared and discussed in this paper. This is becausea well-designed sensor — actuator collocation configuration
can provide a simpler control algorithm with excellent performance and stability, especially when velocity feedback is adopted.
As an ideal point collocation pair of a sensor and actuator shows high possibility in actual vibration control problems, the
advantage of a collocated accelerometer — shaker pair is proven experimentally and discussed first. Then as a similar approach,
a collocated piezosensor — piezoactuator pair is analyzed in depth with the in-plane motion coupling. Finally, two configurations
of a practically collocated configuration with an accelerometer — piezoactuator pair and a non-overlapped collocated pair
of a bimorph piezosensor — two bimorph piezoactuators are described in detail in terms of performance and stability with experimental
results. Those two configurations are expected for the applications to more practical active control of vibration systems
with the velocity feedback control scheme. 相似文献
16.
Sang-Mae Lee Kook-Chan Ahn Jim S. Sirkis 《Journal of Mechanical Science and Technology》2001,15(3):309-319
This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2 nm and ∼9 %, respectively, at a wavelength of ∼1552 nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200 °C temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132 nm/°C with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance. 相似文献
17.
I. Yu. Bezotosnii A. I. Mis’kevich B. S. Salamakha D. I. Fomin 《Instruments and Experimental Techniques》2010,53(2):314-318
The design of a facility for studying luminescence of cryogenic liquids (nitrogen and helium) is described. Luminescence is
excited by ∼0.573-MeV β particles and 0.656-MeV positrons emitted by a radioactive source based on 64Cu radionuclide, which is immersed in a liquid. 相似文献
18.
D. V. Volosnikov A. V. Sivtsov P. V. Skripov A. A. Starostin 《Instruments and Experimental Techniques》2000,43(1):134-139
A method of controlled pulse heating of low-inertia thermal probe immersed into the liquid under study with a temperatureT
0 is described. The control system provides a “temperature plateau”-type heating mode, which consists in a rapid (t
1∼10 μs) increase in the mass-average probe temperature
to a chosen valueT
pl
≫T
0
and maintains this value for a certain time interval (t
2∼103–102 μs) to within 1 K. Thermal effusivity of the substance, in relative units, is determined from the value of its internal heat
flux. Sensitivity to changes in the thermal effusivity of a reference substance was 10−4. Due to the short pulse length and fine tuning of theT
pl value, the method allows one to conduct step-by-step scanning of “instantaneous” thermal properties of a substance in the
region of its short-lived states. 相似文献
19.
This article describes a smiple and low-cost Czerny-Turner spectrograph capable to operate in spectral range from approximately
350–900 nm. A sine drive assembly was used for linearizing the wavelength scale. The wavelength and pixel position calibration
problem have been solved using light sources with known wavelength emission lines, and a polynomial fitting method to find
the relationship between diffraction wave-lengths and pixel numbers. The pixel resolution ∼0.015 nm/pixels and FWHM ∼0.1 nm
at 170 μm entrance slit width are sophisticated enough to serve well in a research laboratory, yet is simple and inexpensive
enough to be affordable for educational use. 相似文献
20.
Detecting near-threshold nucleon production reactions is one of the tasks that must be performed by the CMD-3 cryogenic magnetic detector operating at the Budker Institute of Nuclear Physics. Events of neutron-antineutron pair production, followed by antineutron annihilation, are detected by the detector calorimeters. The energy range differing by ∼25 MeV from the nucleon-producing threshold is the most interesting region for studying such events. At energies such as these, antineutrons annihilate in a cylindrical liquid-xenon calorimeter ≥5 ns after the beams collide. For reliable identification of these events, it is necessary that the flight time of these particles to the calorimeter be determined with an accuracy of 3 ns or better. The calorimeter is composed of a set of ionization chambers with the anode and cathode readout. The time of charge collection from the anode cells is 4.5 μs. Therefore, for the instant when a signal appears in the calorimeter to be determined with a required accuracy, a special signal processing method has been developed, with which it is possible to measure the arrival time of the calorimeter signals with the required accuracy in the real time mode. The prototype of the developed measuring channel has been tested. The test results basically satisfy the requirements: for the arriving signal equivalent to the deposited energy of 200 MeV, the measured time resolution is 3.1 ns, which is close to the calculated value of 2.9 ns. 相似文献