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J. Comput. Sci. Eng.
Vol. 43 (2019) 1069-1080 |
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Direction vector
model and block format numerical method for multi-body
system dynamics |
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Zhen Wang, Jieyu Ding |
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J. Comput. Sci. Eng. 43 (2019) 1069-1076！Published
20 September 2019 |
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Abstract:
The direction vector method is used to describe the
dynamic model of multi-body system. The DAEs of index 3
is transformed into the equation of index 2 or 1. The
L-stable block format and the Multi-step block format
are constructed to simulate the dynamics of the
multi-body system for a long time. The simulation
results show that the L-stable block format and the
Multi-step block format can solve the equations of index
1, 2 and 3 under the same time step size. And the
results are better than the classical Runge-kutta method
in maintaining the energy error, displacement
constraint, velocity constraint and acceleration
constraint. The L-stable block scheme constructed by
Chebyshev polynomials is better than the L-stable block
scheme constructed by equidistant nodes for solving the
DAEs with index 3. L-stable block format and Multi-step
block format can still maintain good calculation
accuracy, which can overcome the disadvantage of
Runge-kutta method under the long time simulation.
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Keywords:
Multi-body system dynamics; Direction vector method;
Differential-algebraic equations; L- stable block
format; Multi-step block format.
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Download (free)
CSE-PDF |
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The Design of
Automatic Picking-up Tennis Car |
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Yuanpeng Jia, Yangrui Zhou, Tengfei Zhuang, Honghao Chu,
Peijiang Chen |
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J. Comput. Sci. Eng. 43 (2019) 1077-1080！Published
20 September 2019 |
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Abstract:
Tennis is a popular sport. It takes time and effort to
pick up the ball manually. In order to solve the problem
of picking up the tennis balls on the tennis court and
improve the efficiency of picking up the balls on the
court, an automatic picking up tennis car is designed.
The vision sensor is used as a tool of image acquisition
and pre-processing. High performance single chip
microcomputer is used as control system, infrared sensor
and ultrasonic sensor are used for distance measurement,
obstacle avoidance and motor drive. A small vacuum pump
is used as a ball suction device, which can
automatically identify, locate and pick up tennis balls.
In addition, the car also has wireless charging function
to ensure that the car can work for a long time.
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Keywords:
Tennis; Visual recognition; Tennis picking-up; Vacuum
pump; Motor drive; Wireless charging.
:
Download (free)
CSE-PDF |
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！！ from ACSS |