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131.
132.
A network for motion detection of an approaching object without influence of the moving background was proposed based on the
insect visual system. The two-dimensional array of the analog complementary metal oxide semiconductor (CMOS) circuits for
extracting the edge signals of the approaching object without outputting those of the moving background was inserted at the
first stage of the network. At the next stage, analog CMOS circuits for detection of approaching velocity and direction, which
accept the extracted edge signals, were inserted based on the locust vision system. A chip of the proposed network was fabricated
with the 1.2 mm CMOS process. It was clarified from the measured results and the simulation results with the simulation program
with integrated circuit emphasis (SPICE) that the two-dimensional circuits of the first stage can only generate the signals
of target edges. The measured results showed that the chip can detect the approaching velocity and direction of the target
in the image which contains the moving background. 相似文献
133.
用于印刷电路板缺陷检测的光学视觉 总被引:4,自引:0,他引:4
本文提出了一种利用光学形态变换探测印刷电路板缺陷的新方法。以非相干光学相关器为基础,构成了一个实现印刷电路板微小缺陷检测的形态变换光学视觉系统给出了原理性实验结果。 相似文献
134.
135.
An apparatus for the measurement of liquid complex shear viscosity in the frequency range 80–2500 Hz, with the use of a torsion pendulum operating in forced oscillation, is described. The drive and detection system consists of a magnet inside the pendulum, two excitation and two measuring coils. The determination of the complex shear viscosity is based on the measurement of the resonance frequency and the damping of the torsion pendulum.The feasibility of this method is demonstrated with a number of Newtonian liquids in the viscosity range 0.3 to 60 m Pa s. Results for a viscoelastic polymer solution are presented. A comparison is made with other apparatus working in the same frequency range.
a
coil height
-
A
apparatus constant
-
B
magnetic induction
-
C
1,C
2
apparatus constants
-
d
diameter torsion rod
-
D
pendulum damping
-
E
apparatus constant
-
F
0
top frequency
-
G
shear modulus torsion rod
-
G
* =G + iG
complex shear modulus
-
h
length torsion rod
-
H
transfer function
-
i
-
I
moment of inertia
-
J
0
excitation-current amplitude
-
J
exc
excitation current
-
K
torsion spring constant
-
l
length pendulum mass
-
M
torque
-
n
number of coil turns
-
p
dipole moment
-
Q =
0/
mechanical quality
-
r
radius pendulum mass
-
R
Re {Z}
-
t
time
-
T
temperature
-
U
induction voltage
-
U
0
induction-voltage amplitude
-
x
distance
-
X
Im {Z}
-
Z = R + iX
liquid impedance
-
Z
cyl
characteristic cylindrical impedance
-
Z
pl
characteristic plane impedance
-
angle
-
M
coefficient of linear expansion of the pendulum mass
-
R
coefficient of linear expansion of the torsion rod
-
rate of shear
-
penetration depth
-
steady-state viscosity
-
s
solvent viscosity
-
angular displacement
-
0
angular-displacement amplitude
-
µ
0
=4 10–7 Vs/Am
-
density
-
phase angle
-
angular frequency
-
0
top angular frequency
-
band-width 相似文献
136.
陀螺漂移测试转台无刷直流力矩电机系统中存在波动力矩和负载力矩振动,这严重地影响了转台速率平稳度。为提高转台速率状态位置跟踪精度,设计了一种自适应补偿方法。该方法包含一个参自适应律和等效PID控制律,它利用前馈补偿原理,来估计电机中未知参数以及波动力矩和负载力矩参数并给与补偿。该自适应补偿方法保证了闭环系统全局稳定性和对期望位置信号的渐进跟踪。仿真结果证明:该方法有效地提高了转台速率状态跟踪精度。 相似文献
137.
Peng Cheng Ph.D. Michael A. Sutton Hubert W. Schreier Ph.D. Student Stephen R. McNeill 《Experimental Mechanics》2002,42(3):344-352
A full-field speckle pattern image correlation method is presented that will determine directly the complete, two-dimensional
deformation field during the image correlation process on digital images obtained using computer vision systems. In this work,
a B-Spline function is used to represent the object deformation field throughout the entire image area. This is an improvement
over subset-based image correlation methods by implicitly maintaining position and derivative continuity constraints among
subsets up to a specified order. The control point variables within the B-Spline deformation function are optimized iteratively
with the Levenberg-Marquardt method to achieve minimum disparity between the predicted and actual deformed images. Results
have shown that the proposed method is computationally efficient, accurate and robust. The general framework of this method
can be applied ton-dimensional image correlation systems that solve for multi-dimension vector fields. 相似文献
138.
介绍了采用数字随动系统解决模拟伺服回路的设计技术,即选用智能化运动控制处理器用于无刷或有刷直流电动机控制。这种技术具有实时采集,操作简单,可靠性高,精度高等优点,在导航系统、雷达系统、火炮系统、汽车等领域具有广阔的发展前景。 相似文献
139.
本文提出根据白光散斑图像数据模拟刚体位移复位的相关性恢复方法,以解决物体大变位情况下的变形测量问题 相似文献
140.
面对需要实时计算的相机位姿估计问题,针对经典的广泛应用的正交迭代算法,提出了一种加速正交迭代算法。其关键思想是将每一次迭代过程规整化,从而提炼出每一次迭代的重复计算,若将此重复计算在迭代开始前提前计算,则可以大幅度的减少迭代过程中的计算量,使得每一次迭代的计算复杂度从O(n)降低为O(1)。因此,可以在更短的时间内迭代更多的次数,从而获得更高的精度。进行了对比实验,结果显示本加速算法计算精度更高,速度更快。并通过实验提出了选择稳健n点透视(RPn P)计算初值,再使用加速正交迭代算法进行迭代运算的方法,在控制点不多的情况下,是一种精度接近最大似然估计,计算速度最快的算法。 相似文献