Abstract: This paper presents investigation effects of a sharp edged gust on aeroelastic behavior and time-domain response of a typical section model using Jones approximate aerodynamics for pure plunging motion. Flutter analysis has been done by using p and p-k methods developed for presented finite-state aerodynamic model for a typical section model (airfoil). Introduction of gust analysis as a linear set of ordinary differential equations in a simplified procedure has been carried out by using transformation into an eigenvalue problem.
Abstract: One of the main trouble in a steel strip manufacturing
line is the breakage of whatever weld carried out between steel coils,
that are used to produce the continuous strip to be processed. A weld
breakage results in a several hours stop of the manufacturing line. In
this process the damages caused by the breakage must be repaired.
After the reparation and in order to go on with the production it will
be necessary a restarting process of the line. For minimizing this
problem, a human operator must inspect visually and manually each
weld in order to avoid its breakage during the manufacturing process.
The work presented in this paper is based on the Bayesian decision
theory and it presents an approach to detect, on real-time, steel strip
defective welds. This approach is based on quantifying the tradeoffs
between various classification decisions using probability and the
costs that accompany such decisions.
Abstract: This work presents a study on the abrasive water jet
(AWJ) machining. An explicit finite element analysis (FEA) of
single abrasive particle impact on stainless steel 1.4304 (AISI 304) is
conducted. The abrasive water jet machining is modeled by FEA
software ABAQUS/CAE. Shapes of craters in FEM simulation
results were used and compared with the previous experimental and
FEM works by means of crater sphericity. The influence of impact
angle and particle velocity was observed. Adaptive mesh domain is
used to model the impact zone. Results are in good agreement with
those obtained from the experimental and FEM simulation. The
crater-s depth is also obtained for different impact angle and abrasive
particle velocities.
Abstract: This paper presents and discusses the numerical simulations of transient laminar natural convection cooling of high Prandtl number fluids in cubical cavities, in which the six walls of the cavity are subjected to a step change in temperature. The effect of the fluid Prandtl number on the heat transfer coefficient is studied for three different fluids (Golden Syrup, Glycerin and Glycerin-water solution 50%). The simulations are performed at two different Rayleigh numbers (5·106 and 5·107) and six different Prandtl numbers (3 · 105 ≥Pr≥ 50). Heat conduction through the cavity glass walls is also considered. The propsed correlations of the averaged heat transfer coefficient (N u) showed that it is dependant on the initial Ra and almost independent on P r. The instantaneous flow patterns, temperature contours and time evolution of volume averaged temperature and heat transfer coefficient are presented and analyzed.
Abstract: This research deals with investigations on the “Active
Generator" under rotor speed variations and output frequency
control. It runs at turbine speed and it is connected to a three phase
electrical power grid which has its own frequency different from
turbine frequency. In this regard the set composed of a four phase
synchronous generator and a natural commutated matrix converter
(NCMC) made with thyristors, is called active generator. It replaces a
classical mechanical gearbox which introduces many drawbacks. The
main idea in this article is the presentation of frequency control at
grid side when turbine runs at variable speed. Frequency control has
been done by linear and step variations of the turbine speed. Relation
between turbine speed (frequency) and main grid zero sequence
voltage frequency is presented.
Abstract: In this work, we suggested a new approach for the
control of a mobile robot capable of being a building block of an
intelligent agent. This approach includes obstacle avoidance and goal
tracking implemented as two different sliding mode controllers. A
geometry based behavior arbitration is proposed for fusing the two
outputs. Proposed structure is tested on simulations and real robot.
Results have confirmed the high performance of the method.
Abstract: In this paper, a solution is presented for a robotic
manipulation problem in industrial settings. The problem is sensing
objects on a conveyor belt, identifying the target, planning and
tracking an interception trajectory between end effector and the
target. Such a problem could be formulated as combining object
recognition, tracking and interception. For this purpose, we integrated
a vision system to the manipulation system and employed tracking
algorithms. The control approach is implemented on a real industrial
manipulation setting, which consists of a conveyor belt, objects
moving on it, a robotic manipulator, and a visual sensor above the
conveyor. The trjectory for robotic interception at a rendezvous point
on the conveyor belt is analytically calculated. Test results show that
tracking the raget along this trajectory results in interception and
grabbing of the target object.
Abstract: In automotive systems almost all steps concerning the
calibration of several control systems, e.g., low idle governor or
boost pressure governor, are made with the vehicle because the timeto-
production and cost requirements on the projects do not allow for
the vehicle analysis necessary to build reliable models. Here is
presented a procedure using parametric and NN (neural network)
models that enables the generation of vehicle system models based
on normal ECU engine control unit) vehicle measurements. These
models are locally valid and permit pre and follow-up calibrations so
that, only the final calibrations have to be done with the vehicle.
Abstract: This paper presents the approach to design the Auto-
Tuning PID controller for interactive Water Level Process using
integral step response. The Integral Step Response (ISR) is the
method to model a dynamic process which can be done easily,
conveniently and very efficiently. Therefore this method is advantage
for design the auto tune PID controller. Our scheme uses the root
locus technique to design PID controller. In this paper MATLAB is
used for modeling and testing of the control system. The
experimental results of the interacting water level process can be
satisfyingly illustrated the transient response and the steady state
response.
Abstract: Since the 1990s the American furniture industry faces a transition period. Manufacturers, one of its most important actors made its entrance into the retail industry. This shift has had deep consequences not only for the American furniture industry as a whole, but also for other international furniture industries, especially the Chinese. The present work aims to analyze this actor based on the distinction provided by the Global Commodity Chain Theory. It stresses its characteristics, structure, operational way and importance for both the U.S. and the Chinese furniture industries.
Abstract: This paper proposes a framework for product
development including hardware and software components. It
provides separation of hardware dependent software, modifications of
current product development process, and integration of software
modules with existing product configuration models and assembly
product structures. In order to decide the dependent software, the
framework considers product configuration modules and engineering
changes of associated software and hardware components. In order to
support efficient integration of the two different hardware and
software development, a modified product development process is
proposed. The process integrates the dependent software development
into product development through the interchanges of specific product
information. By using existing product data models in Product Data
Management (PDM), the framework represents software as modules
for product configurations and software parts for product structure.
The framework is applied to development of a robot system in order to
show its effectiveness.
Abstract: It is well known that a linear dynamic system including
a delay will exhibit limit cycle oscillations when a bang-bang sensor
is used in the feedback loop of a PID controller. A similar behaviour
occurs when a delayed feedback signal is used to train a neural
network. This paper develops a method of predicting this behaviour
by linearizing the system, which can be shown to behave in a manner
similar to an integral controller. Using this procedure, it is possible
to predict the characteristics of the neural network driven limit cycle
to varying degrees of accuracy, depending on the information known
about the system. An application is also presented: the intelligent
control of a spark ignition engine.
Abstract: Process-oriented software development is a new
software development paradigm in which software design is modeled
by a business process which is in turn translated into a process
execution language for execution. The building blocks of this
paradigm are software units that are composed together to work
according to the flow of the business process. This new paradigm
still exhibits the characteristic of the applications built with the
traditional software component technology. This paper discusses an
approach to apply a traditional technique for software component
fabrication to the design of process-oriented software units, called
process components. These process components result from
decomposing a business process of a particular application domain
into subprocesses, and these process components can be reused to
design the business processes of other application domains. The
decomposition considers five managerial goals, namely cost
effectiveness, ease of assembly, customization, reusability, and
maintainability. The paper presents how to design or decompose
process components from a business process model and measure
some technical features of the design that would affect the
managerial goals. A comparison between the measurement values
from different designs can tell which process component design is
more appropriate for the managerial goals that have been set. The
proposed approach can be applied in Web Services environment
which accommodates process-oriented software development.
Abstract: The limit load carrying capacity of functionally
graded materials (FGM) circular plates subjected to an arbitrary
rotationally symmetric loading has been computed. It is provided that
the plate material behaves rigid perfectly plastic and obeys either the
Square or the Tresca yield criterion. To this end the upper and lower
bound principles of limit analysis are employed to determine the
exact value for the limiting load. The correctness of the result are
verified and finally limiting loads for two examples namely; through
radius and through thickness FGM circular plates with simply
supported edges are calculated, respectively and moreover, the values
of critical loading factor are determined.
Abstract: This paper presents the communication network for
machine vision system to implement to control systems and logistics
applications in industrial environment. The real-time distributed over
the network is very important for communication among vision node,
image processing and control as well as the distributed I/O node. A
robust implementation both with respect to camera packaging and
data transmission has been accounted. This network consists of a
gigabit Ethernet network and a switch with integrated fire-wall is
used to distribute the data and provide connection to the imaging
control station and IEC-61131 conform signal integration comprising
the Modbus TCP protocol. The real-time and delay time properties
each part on the network were considered and worked out in this
paper.
Abstract: Car failure detection is a complicated process and
requires high level of expertise. Any attempt of developing an expert
system dealing with car failure detection has to overcome various
difficulties. This paper describes a proposed knowledge-based
system for car failure detection. The paper explains the need for an
expert system and the some issues on developing knowledge-based
systems, the car failure detection process and the difficulties involved
in developing the system. The system structure and its components
and their functions are described. The system has about 150 rules for
different types of failures and causes. It can detect over 100 types of
failures. The system has been tested and gave promising results.