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ENGINEERING NEWS IN BRIEF
E-Mail Newsletter
No.92
Issued by the Asian TOP Panel, August 2009
The Chinese Mechanical Engineering Society
(CMES)
The Institution of Engineers, Indonesia (PII)
The Japan Society of Mechanical Engineers
(JSME)
The Korean Society of Mechanical Engineers
(KSME)
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According to the agreement
made in the 2nd Asian TOP Panel Meeting,
the ENGINEERING NEWS IN BRIEF (E-mail newsletter)
has now been edited
by the JSME for the year 2009.
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[Contents]
1) The Outline of Improvement on Vehicle Dynamic
Simulator (Source: JSME)
2) An Effective Internal Control Reflecting
Company’s Corporate Social Responsibility
Philosophy (CSR)
?To Eliminate Risks of being Committed with
the Mislabeling
Scandal Conduct-
(Source: JSME)
3) Development of Centerless Grinder with Automatic
Changeover Function
(Source: JSME)
4) Quasi-linearization of non-linear systems
under random vibration by probabilistic
method (Source: KSME)
5) A path Tracking Control Algorithm for Underwater Mining Vehicles
(Source: KSME)
6) Dynamic Response Characteristics of Seismic Isolation Systems for Building
Structures (Source: KSME)
7) Modulus of Elasticity and Yield Bending Stress of Coating Lubrotec 19985
Produced by the Metal Spraying Process (Source: KSME)
8) Orthogonal Design and Analyses of Hydraulic
Bridge for Water Servo Valve
(Source: CMES)
9) Optimal Motion Planning for Differentially
Flat Underactuated Mechanical Systems (Source:
CMES)
10) Flow Analysis and Optimization of Port-plate
Centrifugal Pump in Electric Motor
Pump (Source:
CMES)
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1) The Outline of Improvement on Vehicle Dynamic
Simulator (Source: JSME)
Tomohiro Otsuka, Central Japan Railway Company
We have been carring out the development
and verification of riding comfort
improvement
plan of TOKAIDO SHINKANSEN trunk line
using
vehicle dynamic simulator. As the result,
the riding comfort of TOKAIDO SHINKANSEN
trunk line has been realized in good
condition.
Recently, we improved vehicle dynamic
simulator
in order to carry out the deepening
of further
study(ex. the riding comfort in high
frequency
range).In improving vehicle dynamic
simulator
,we changed control system and miniaturization
and lighting of the equipment cabin
in order
to realizing high performance. As the
result,
we improved the double performance
further
than conventional vehicle dynamic simulator.
In future, we will be verifing of the
riding
comfort in high frequency range and
tackling
the equipment development of improving
the
riding comfort of TOKAIDO SHINKANSEN
trunk
line by using result of study.
________________________________________________________________________________________________________________________________
2) An Effective Internal Control Reflecting
Company’s Corporate Social Responsibility
Philosophy (CSR) -To Eliminate Risks of being
Committed with the Mislabeling Scandal Conduct-
Naochika Tamura, InterRisk Research Institute
& Consulting, Inc.
Japanese people have been quite familiar
with the dairy news concerning new
mislabeling
scandals committed by Japanese companies.
Once a company is revealed with its
scandal,
it will find itself caught in a cross
fire
of serious criticism by consumers and
mass
media, and then on the verge of crisis. For a company, one of the most effective
measures to eliminate risks of being
committed
with the mislabeling scandal conduct
is to
enforce its own internal control -
consisted
mainly of ‘Compliance’ and ‘Risk
Management’. Above all, in order to establish effective
internal control (system), a company
must
be certain that its management policy
fully
reflects its CSR philosophy and that
both
of its executives and staff are acquainted
with it sufficiently.
_________________________________________________________________________________________________________________________________
3) Development of Centerless Grinder with Automatic
Changeover Function
Mohei Sagae, Micron Machinery Co., Ltd
In centerless grinding, changeover time reduction
has been an important element of lean thinking
for a number of years. Especially in throughfeed
grinding, some processes of changeover will
be required as well as special training in
order to adjust tooling. In 1994, Micron
Machinery developed an MSL-600III model,
equipped with the oblique cross slides that
introduced the concept "contact point
constant." Previously, the changeover
method was to keep the workpiece-to-regulating
wheel contact point constant before and after
changeover, in order to omit any manual adjustments
on the tools with contact to the workpiece.
As a result, the automatic changeover function
was realized in throughfeed centerless grinding.
In 2008, the MFC-600VI model was developed
in order to introduce the new concept "contact
point control." By controlling the grinding
wheel, regulating wheel, and workrest, which
are in contact with the workpiece, the three
contact points on the workpiece can be independently
and precisely controlled in a changeover.
This will expand the application of automatic
changeovers and advance the quality and stability
of the finished workpieces, in both throughfeed
grinding and infeed grinding.
_________________________________________________________________________________________________________________________________
4) Quasi-linearization of Non-linear Systems
under Random Vibration by Probabilistic
Method
Sin-Young Lee,Kunsan National University
Vibration of a non-linear system under random
parametric excitations was evaluated by probabilistic
methods. The non-linear characteristic terms
of a system were quasi-linearized and excitation
terms remained as they were. An analytical
method where the square mean of error was
minimized was used. An alternative method
was an energy method where the damping energy
and restoring energy of the linearized system
were equalized to those of the original nonlinear
system. The numerical results were compared
with those obtained by Monte Carlo simulation.
A new method was proposed from the comparison
of those results. Finally the results obtained
by the combined method showed good agreement
with those obtained by Monte Carlo simulation.
_________________________________________________________________________________________________________________________________
5) A path Tracking Control Algorithm for
Underwater Mining Vehicles
Sup Hong, MOERI/KORDI
In this paper, a path tracking control
algorithm is formulated for the use of tracked
underwater mining vehicles. The algorithm
consists of two parts, the forward velocity
control and the heading angle control. The
control algorithm is designed based on kinematics,
and it considers the track slips and the
longitudinal and yaw dynamic models of the
tracked vehicle including the soil-track
interaction force model. The desired heading
angle is obtained by the so-called "Line
of Sight" method. The suggested algorithm
is tested by numerical simulations using
the TRACSIM software developed by MOERO/KORDI,
Korea. After the control gains are tuned
by a series of numerical simulations, the
algorithm is verified on a scale vehicle
on air on a soil bin test bed containing
the cohesive soil of the Bentonite-water
mixture.
_________________________________________________________________________________________________________________________________
6) Dynamic Response Characteristics of Seismic
Isolation Systems for Building
Structures
Beom-Soo Kang,
Pusan National University
Isolation is an effective method of
reducing effects of seismic events on building
structures. Steel-reinforced elastomeric
isolator (SREI) is one kind of isolation
system which is used extensively, but there
are some problems associated with its use,
such as cost and weight. Fiber-reinforced
elastomeric isolator (FREI) has been developed
in an attempt to solve the problems of high
cost and heavy weight for SREI. In this study,
mechanical properties for the SREI and the
FREI are investigated. Systematic dynamic
response analyses are performed for three
different models such as a fixed based, an
SREI based and an FREI based low-story building
structures. Two-dimensional and threedimensional
dynamic response analysis results for each
model are compared in terms of displacement,
drift, acceleration and shear force in this
study. In the two-dimensional dynamic response
analysis, the SREI and the FREI based structures
are proven to be the more effective isolation
systems against seismic events by comparing
with the fixed based one. As a result, the
FREI has shown better isolation performances
than that of the SREI. Furthermore, to extract
the characteristics of the FREI on building
structure resisting the seismic effects,
two models of three-dimensional framed structure
with fixed bases and FREI isolated bases
are built, respectively. After the dynamic
response analysis of these two structures
subjected to bi-directional ground motions,
the analyzed results are compared with each
other. It is shown that the FREI could effectively
absorb the seismic energy, and decreases
the destructive effects acting on a building
structure due to ground horizontal motions
that could occur in an earthquake.
________________________________________________________________________________________________________________________________
7) Modulus of Elasticity and Yield Bending
Stress of Coating Lubrotec 19985 Produced
by the Metal Spraying
Process (Source: KSME)
Nabil B. Sada, Tafila
Technical University
Round bars of 13.6 mm diameter
made
from low alloy steel were sprayed by
hard-coating
Lubrotec 19985 under the following
spraying
parameters: the rotation speed varied
from
500 to 900 rpm, the feeding speed from
0.1
to 1.0 mm/rev, and the nozzle tip distance
from 100 to 200 mm; the sprayed bars
were
then subjected to bending test. Depending
on the thickness of the produced coating,
the modulus of elasticity and yield
bending
stress of the coating were calculated
by
applying the bending deflection formula
and
an equivalent cross-sectional area
technique,
respectively. The results obtained
indicated
that the thickness, hardness, yield
bending
stress, and modulus of the elasticity
of
coating were varied with the variation
in
spraying parameters. The optimum spraying
parameter was a rotation speed of 700
r.p.m,
a nozzle tip distance of 200 mm, and
a feed
rate of 0.1 mm/rev. This optimum parameter
produced an acceptable thickness of
1.14
mm, a hardness of 148 HV, a bending
stress
of 404.9 MPa, and a modulus of elasticity
of 91.47 GPa. The results obtained
can also
help determine the modulus of elasticity
and yield bending stress of the various
coating
materials when a coated round bar is
subjected
to the bending test.
_____________________________________________________________________________________________________________________________
8) Orthogonal Design and Analyses of Hydraulic
Bridge for Water Servo Valve
Nie Songlin,
Kong Xiangcun, Jia Guotao
Beijing University
of Technology
A new type of double nozzle-flapper
water hydraulic servo bridge model is developed,
in which the two tandem fixed dampers are
adopted as prepositive dampers. The parameter
sensitivity analysis for the hydraulic bridge
is carried out. The relationship among the
flapper displacement, the spool speed and
the pressure at the two ends of the spool
is investigated. The orthogonal design is
employed to study the influence of the physics
factors on the characteristics of the hydraulic
bridge, such as the diameter of the nozzle,
the diameters of the two tandem fixed dampers,
the spool diameter and its sliding speed,
the initial clearance between nozzle and
flapper. The results reveal that (1) the
smaller initial clearance between nozzle
and flapper, the lager diameter of spool
and the clearance between spool and valve
body, the shorter overlap length of spool
and valve body, and the higher system pressure,
will lead to the better linearity of the
control characteristics for the water hydraulic
bridge;(2) for hydraulic bridge of water
servo valve including the two-stage dampers,
the smaller first damper diameter, the larger
second damper diameter, the smaller pipe
diameter before the nozzle, the larger diameter
of spool and the clearance between spool
and valve body, will bring the higher dynamic
response in the water hydraulic bridge. These
research results will lay the theoretical
foundation for the development of water hydraulic
servo valve.
Key Words: Water hydraulics, Servo
valve,
Hydraulic bridge, Two-stage dampe,
Orthogonal
design
________________________________________________________________________________________________________________________________
9) Optimal Motion Planning for Differentially
Flat Underactuated Mechanical Systems
He Guangping,
Geng Zhiyong
Peking University,
North China University of Technology
Underactuated mechanical system has
less independent inputs than the degrees
of freedom (DOF) of the mechanism. The energy
efficiency of this class of mechanical systems
is an essential problem in practice. On the
basis of the sufficient and necessary condition
that concludes a single input nonlinear system
is differentially flat, it is shown that
the flat output of the single input underactuated
mechanical system can be obtained by finding
a smooth output function such that the relative
degree of the system equals to the dimension
of the state space. If the flat output of
the underactuated system can be solved explicitly,
and by constructing a smooth curve with satisfying
given boundary conditions in flat output
space, an energy efficiency optimization
method is proposed for the motion planning
of the differentially flat underactuated
mechanical systems. The inertia wheel pendulum
is used to verify the proposed optimization
method, and some numerical simulations show
that the presented optimal motion planning
method can efficaciously reduce the energy
cost for given control tasks.
Key Words: Differential flatness, Underactuated
system, Motion planning Optimization
_________________________________________________________________________________________________________________________________
10) Flow Analysis and Optimization of Port-plate
Centrifugal Pump in Electric Motor
Pump
Ji Hong, Ding
Dali, Wang Zhengrong, Wang Xiuyong, Sun Lei,
Hu Qihui
Lanzhou University
of Technology
Based on the principle of centrifugal
pump and the idea of compact design, an electric-motor-pump
is developed. It is integrated by an electric
motor, a hydraulic vane pump and a port-plate
centrifugal pump as a compact hydraulic power
unit. The vane pump is as the main pump of
the unit. The port-plate centrifugal pump
is designed specially for the main pump to
improve the suction performance of the electric-motor-pump.
The integrated pump demonstrates some attractive
advantages such as more compact structure,
lower noise, higher efficiency and no external
leakage. By computational fluid dynamics
(CFD) method, the effects of the main structural
parameters of the port-plate centrifugal
pump on its outlet pressure and the efficiency
are investigated. The design rules for the
port-plate centrifugal pump are concluded.
This simulation results show that the port-plate
centrifugal pump can raise the inlet pressure
of the main pump obviously. When the slope
angle of the eccentric tube is 45°and the
bias angle is between 45°-60°,the maximum
power consumption is only about 0.41% of
the electric-motor-pump, which also shows
that the port-plate centrifugal pump almost
do not influences the whole power characteristics
of the electric-motor-pump. Its efficiency
can be above 95%, and the whole efficiency
of the centrifugal pump including the outlet
channel is 22%. Power loss occurs due to
eddy flow from the outlet of the centrifugal
pump to the outlet channel to the main pump.
Key Words: Electric motor pump, Port-plate
centrifugal pump, Flow analysis, Structure
optimization
________________________________________________________________________________________________________________________________
Editor : International Affairs Committee
Published by The Japan Society of Mechanical
Engineers
Shinanomachi-Rengakan Bldg, Shinanomachi
35,
Shinjuku-ku, Tokyo 160-0016, Japan
FAX : 81-3-5360-3508
All Rights Reserved, Copyright C 2009
The Japan Society of Mechanical Engineers
URL:http//www.jsme.or.jp [English Version]
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