共查询到20条相似文献,搜索用时 46 毫秒
1.
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
2.
Liang Xinhua Zhu Ping Lin Zhongqin Zhang Yan 《Frontiers of Mechanical Engineering in China》2007,2(1):99-103
A lightweight automotive prototype using alternative materials and gauge thickness is studied by a numerical method. The noise,
vibration, and harshness (NVH) performance is the main target of this study. In the range of 1–150 Hz, the frequency response
function (FRF) of the body structure is calculated by a finite element method (FEM) to get the dynamic behavior of the auto-body
structure. The pressure response of the interior acoustic domain is solved by a boundary element method (BEM). To find the
most contributing panel to the inner sound pressure, the panel acoustic contribution analysis (PACA) is performed. Finally,
the most contributing panel is located and the resulting structural optimization is found to be more efficient.
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Translated from Journal of Shanghai Jiaotong University, 2006, 40(1): 177–180 [译自: 上海交通大学学报] 相似文献
3.
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
4.
Acoustic-structure sensitivity is used to predict the change of acoustic pressure when a structure design variable is changed.
The sensitivity is significant for reducing noise of structure. Using FEM (finite element method) and BEM (boundary element
method) acoustic-structure sensitivity was formulated and presented. The dynamic response and response velocity sensitivity
with respect to structure design variable were carried out by using structural FEM, the acoustic response and acoustic pressure
sensitivity with respect to structure velocity were carried out by using acoustic BEM. Then, acoustic-structure sensitivity
was computed by linking velocity sensitivity in FEM and acoustic sensitivity in BEM. This method was applied to an empty box
as an example. Acoustic pressure sensitivity with respect to structure thickness achieved in frequency ranges 1–100 Hz, and
its change rule along with stimulating frequency and design variable were analyzed. Results show that acoustic-structure sensitivity
method linked with FEM and BEM is effective and correct.
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Translated from Journal of Vibration Engineering, 2005, 18(3): 366–370 [译自: 振动工程学报] 相似文献
5.
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
6.
Based on the principle of alternative operation of two bending vibration modes in an annular stator, this paper presents a
standing-wave stepping ultrasonic motor characterized by no accumulative errors driven by an open-loop control circuitry.
The driving forces are generated from the motions of projections on the stator in two modes. The positioning of the motor
is achieved by the cooperation between the stator projections and rotor teeth, and the number of the rotors determines the
stepping angle of the motor. Two-phase sinusoidal signals corresponding to the two modal frequencies drive the motor bi-direction
stepping rotation via a switch unit. The prototype runs steadily without miss-step on trial. The single-step angle displacement
of the motor is 2.5°.
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Translated from Journal of Nanjing University of Aeronautics and Astronautics, 2006, 38(5): 600–604 [译自: 南京航空航天大学学报] 相似文献
7.
Shunming HUA Hongzhuang ZHANG Guangming CHENG Zunqiang FAN Jianfang LIU 《Frontiers of Mechanical Engineering in China》2008,3(3):265-269
A piezoelectric film-actuated motion platform with high resolution, which can run in two directions within a horizontal plane,
is presented. On the basis of the analysis of the working principle of a stick-slip mechanism, a mathematical model describing
its dynamic behavior is set up and simulated. Experiments of the motion performance and carrying ability on the prototype
are conducted. Results show that this type of platform has advantages including a simple structure, small volume, light weight,
stable step length, and large traveling range. When the driving voltage is less than 30 V, step error is less than 0.5 mm.
The carrying ability of the platform is terrific and about 7–8 times its weight.
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Translated from Optics and Precision Engineering, 2006, 14(4): 635–640 [译自: 光学精密工程] 相似文献
8.
Image automatic mosaics based on contour phase correlation 总被引:2,自引:0,他引:2
Zhang Jing Hu Zhiping Liu Zhitai Ou Zongying 《Frontiers of Mechanical Engineering in China》2007,2(2):228-234
The image planar mosaics is studied, and an image automatic mosaics algorithm on the basis of contour phase correlation is
proposed in this paper. To begin with, by taking into account mere translations and rotations between images, a contour phase
correlation algorithm is used to realize the preliminary alignments of images, and the initial projective transformation matrices
are obtained. Then, an optimization algorithm is used to optimize the initial projective transformation matrices, and complete
the precise image mosaics. The contour phase correlation is an improvement on the conventional phase correlation in two aspects:
First, the contours of images are extracted, and the phase correlation is applied to the contours of images instead of the
whole original images; Second, when there are multiple peak values approximate to the maximum peak value in the δ function
array, their corresponding translations can be regarded as candidate translations and calculated separately, and the best
translation can be determined by the optimization of conformability of two images in the overlapping area. The running results
show that the proposed algorithm can consistently yield high-quality mosaics, even in the cases of poor or differential lighting
conditions, existences of minor rotations, and other complicated displacements between images.
Translated from Journal of Dalian University of Technology, 2005, 45(1): 68–74 [译自: 大连理工大学学报] 相似文献
9.
An energy reclaiming suspension is proposed to reclaim vibration energy in the suspension. To study its riding performance
and reclaiming energy performance, a hydraulic energy reclaiming device prototype is produced and its mechanical behavior
is analyzed and tested according to the hydraulic theory. Theoretical analysis shows that mechanical behavior of the energy
reclaiming device is embodied by a viscidity damping parameter and an analogous coulomb damping parameter determined by its
structure; their expressions are obtained. Experimental investigation shows that theoretical predictions agree with test results.
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Translated from Journal of Jiangsu University (Natural Science Edition), 2006, 27(1): 35–39 [译自: 江苏大学学报(自然科学版)] 相似文献
10.
A dynamical sliding-mode controller is devised to track the output of mobile manipulators. During the investigation, firstly
a reduced dynamic model considering the dynamics of the driving motor is developed for mobile manipulators. Then, the system
is decomposed into four lower-dimensional subsystems by means of diffeomorphism and nonlinear input transformation. Moreover,
a design method of the dynamical sliding-mode controller that is applied to the output tracking of mobile manipulators is
proposed. The simulation results indicate that the dynamical sliding-mode controller can not only track the given trajectory
correctly but also reduce the chattering of sliding-mode control system considerably.
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Translated from Journal of South China University of Technology (Natural Science Edition), 2006, 34(6): 29–33 [译自: 华南理工大学学报 (自然科学版)] 相似文献
11.
Yinnan Yuan Deqing Mei Zhong Wang Tian Zhang 《Frontiers of Mechanical Engineering in China》2008,3(2):189-192
The combustion and heat release of engines using diesel fuel and bio-diesel fuel have been investigated. The results illustrate
that the combustion happens in advance and the ignition delay period is shortened. The initial heat release peak declines
a little, the corresponding crankshaft angle changes in advance, and the combustion duration is prolonged. The economic performance
and emission features of diesel engines using diesel fuel and bio-diesel fuel are compared. The results also show that the
specific fuel consumption of bio-diesel increases by about 12%. The emissions, such as CO, HC, and particulate matter decrease
remarkably whereas NO
x
increases a little.
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Translated from Journal of Jiangsu University (Natural Science Edition), 2006, 27(3): 216–219 [译自: 江苏大学学报(自然科学版)] 相似文献
12.
Li Zhinong He Yongyong Chu Fulei Wu Zhaotong 《Frontiers of Mechanical Engineering in China》2007,2(1):46-49
A blind identification method was developed for the threshold auto-regressive (TAR) model. The method had good identification
accuracy and rapid convergence, especially for higher order systems. The proposed method was then combined with the hidden
Markov model (HMM) to determine the auto-regressive (AR) coefficients for each interval used for feature extraction, with
the HMM as a classifier. The fault diagnoses during the speed-up and speed-down processes for rotating machinery have been
successfully completed. The result of the experiment shows that the proposed method is practical and effective.
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Translated from Journal of Tsinghua University (Science and Technology), 2005, 45(8): 1 036–1 039 [译自: 清华大学学报(自然科学版)] 相似文献
13.
This paper presents an optimization model for rotor blades of horizontal axis wind turbines. The model refers to the wind
speed distribution function on the specific wind site, with an objective to satisfy the maximum annual energy output. To speed
up the search process and guarantee a global optimal result, the extended compact genetic algorithm (ECGA) is used to carry
out the search process. Compared with the simple genetic algorithm, ECGA runs much faster and can get more accurate results
with a much smaller population size and fewer function evaluations. Using the developed optimization program, blades of a
1.3 MW stall-regulated wind turbine are designed. Compared with the existing blades, the designed blades have obviously better
aerodynamic performance.
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Translated from Journal of Shantou University (Natural Science), 2006, 21(1): 44–49 [译自: 汕头大学学报 (自然科学版)] 相似文献
14.
Chen Wei Yang Jichang Wu Xiaofeng Lu Dun Guo Weigang 《Frontiers of Mechanical Engineering in China》2007,2(4):399-403
Fracture is a common defect in sheet metal forming and it is essentially caused by tensile instability. This paper analyzes
some experiments and theories for building forming limit diagrams of sheet metal and points out the advantages and disadvantages
of current experiments and theories. According to this, a method that integrates the finite element simulation and experiment
was used to research the forming limit diagrams of the sheet metal under complex strain paths. Taking the rear hanger that
undergoes twice stamping as an example, the strain paths of the dangerous point of the rear hanger is investigated. Finally,
the forming method of the rear hanger is confirmed. Results indicate that finite element method (FEM) can achieve the complex
strain paths and different strain paths will have great impacts on the result of the sheet metal forming.
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Translated from Journal of Jiangsu University (Natural Science Edition), 2005, 26(4): 289–293 [译自: 江苏大学学报 (自然科学版)] 相似文献
15.
A novel soft-switching twin arc pulse MAG welding inverter 总被引:1,自引:0,他引:1
Wang Zhenmin Xue Jiaxiang Wang Fuguang Huang Shisheng 《Frontiers of Mechanical Engineering in China》2007,2(2):224-227
The high-speed double wire pulse metal-gas arc (MAG) welding process possesses advantages of automation and high efficiency
and quality. Thus, it attracts much more attention nowadays. To meet the requirements of the double wire pulse MAG welding
process, a novel double wire pulse MAG welding inverter integrated with technologies, such as soft-switching, double closed
loop control, and synchronic control, is produced. A complete performance test was done for the pulsed MAG welding power supply
by using a computer testing platform. The results of the experiment indicate that the novel welding inverter has an excellent
performance both in the dynamic and the static characteristics. Also, the synchronic control between the master inverter and
the slave inverter is reliable.
Translated from Journal of South China University of Technology (Natural Science Edition), 2006, 34(7): 31–34, 59 [译自: 华南理工大学学报 (自然科学版)] 相似文献
16.
The relationship between the arrangement of ceramics and the force coefficient shows that the maximum excitation efficiency
will be obtained when the ceramics are placed at the trough of the first bending mode of the stator. Therefore, a cylindrical
ultrasonic micromotor with a novel stator is proposed. The prototype motor is 5 mm in diameter, 30 mm in length and 4.2 g
in weight. The micromotor operates with the first bending mode at 53 kHz. Its maximum speed is 350 r/min when the drive voltage
is 200 V and the stall torque reaches 2.5 mN · m. As this motor is suitable for miniaturization because of its simple structure,
another cylindrical ultrasonic micromotor is developed. Piezoelectric ceramic tube is used as its stator. This micromtor is
2 mm in diameter, 7 mm in length and 0.258 g in weight. Its speed reaches 813 r/min when the drive voltage is 60 V at 75 kHz.
The operation mechanism, structure and design method of these two motors are introduced.
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Translated from Proceedings of the CSEE, 2006, 26(12): 128–133 [译自: 中国电机工程学报] 相似文献
17.
Zhang Jianming Zhang Weigang Yang Bing Wang Yawei 《Frontiers of Mechanical Engineering in China》2007,2(4):439-441
A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on
the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results
indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen
any excessive control valve poppet bouncing.
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Translated from Journal of Shanghai Jiaotong University, 2006, 40(6): 1031–1034 [译自: 上海交通大学学报] 相似文献
18.
Xu Hongxue Liu Yongxian Guo Xiuying Sheng Zhongqi 《Frontiers of Mechanical Engineering in China》2007,2(2):201-204
According to the specific characteristics of a computer-supported cooperative design (CSCD) system, the characteristics of
role delegation authorization (RDA) are analyzed and deduced, and a set of fitful status is arrived at. Because of the diversified
characteristics of RDA features in different systems, the RDA model has multi-varying status. On the basis of the basic model
of role-based access control (RBAC), some basic characteristics of RDA are summed up. Then, according to the specific characteristics
of CSCD system, the characteristics of RDA are recombined to develop a RDA model that is suitable for the CSCD system. It
is different from the conventional role authorization models of RBAC, that is, it adopts the decentralized authorization management
instead of the centralized one in CSCD system, which makes the management more flexible. This model is verified through a
specific case of CSCD system.
Translated from Journal of Northeastern University (Natural Science), 2006, 27(5): 548–551 [译自: 东北大学学报 (自然科学版)] 相似文献
19.
Based on the Darcy fluid model, by considering the effects of viscous dissipation due to the interaction between solid skeleton
and pore fluid flow and thermal conduction in the direction of the fluid flow, the thermally developing forced convection
of the local thermal equilibrium and the corresponding thermal stresses in a semi-infinite saturated porous plate channel
are investigated in this paper. The expressions of temperature, local Nusselt number and corresponding thermal stresses are
obtained by means of the Fourier series, and the distributions of the same are also shown. Furthermore, influences of the
Péclet number (Pe) and Brinkman number (Br) on temperature, Nusselt number (Nu) and thermal stress are revealed numerically.
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Translated from Journal of Lanzhou University (Natural Science Edition), 2006, 42(2): 114–119 [译自: 兰州大学学报(自然科学版)] 相似文献
20.
An elastohydrodynamic lubrication (EHL) film measurement system using multi-beam interferometry is introduced in this paper.
The measurement principle and the instrumentation are discussed. A simple and efficient method is suggested to obtain the
fringe order of measured points. It is demonstrated that the presented measurement system can provide continuous measurement
of lubricating films from nano to micro scales at a nano-level resolution, and can be used to investigate ultra-thin EHL films
and tiny variations in EHL films.
Translated from Tribology, 2006, 26(2): 150–153 [译自: 摩擦学学报] 相似文献