Abstract: An advanced composite flywheel rotor consisting of
intra and inter hybrid rims was designed to optimally increase the energy capacity, and was manufactured using filament winding with
in-situ curing. The flywheel has recently attracted considerable attention from many investigators since it possesses great potential in
many energy storage applications, including electric utilities, hybrid or
electric automobiles, and space vehicles. In this investigation, a comprehensive study was conducted with the intent to implement
composites in high performance flywheel applications.The inner two
intra-hybrid rims (rims 1 and 2) were manufactured as a whole part
through continuous filament winding under in-situ curing conditions,
and so were the outer two rims (rims 3 and 4). The outer surface of rim
2 and the inner surface of rim 3 were CNC-tapered for press-fitting. Machined rims were finally press-fitted using a hydraulic press with a
maximum compressive force of approximately 1000 ton.
Abstract: This paper presents the experimental results of silicone rubber polymer insulators for 22 kV systems under salt water dip wheel test based on IEC 62217. Straight shed silicone rubber polymer insulators having leakage distance 685 mm were tested continuously 30,000 cycles. One test cycle includes 4 positions, energized, de-energized, salt water dip and deenergized, respectively. For one test cycle, each test specimen remains stationary for about 40 second in each position and takes 8 second for rotate to next position. By visual observation, sever surface erosion was observed on the trunk near the energized end of tested specimen. Puncture was observed on the upper shed near the energized end. In addition, decreasing in hydrophobicity and increasing in hardness were measured on tested specimen comparing with new specimen. Furthermore, chemical analysis by ATR-FTIR was conducted in order to elucidate the chemical change of tested specimens comparing with new specimen.
Abstract: The research on two-wheeled inverted pendulum (TWIP) mobile robots or commonly known as balancing robots have gained momentum over the last decade in a number of robotic laboratories around the world. This paper describes the hardware design of such a robot. The objective of the design is to develop a TWIP mobile robot as well as MATLAB interfacing configuration to be used as flexible platform comprises of embedded unstable linear plant intended for research and teaching purposes. Issues such as selection of actuators and sensors, signal processing units, MATLAB Real Time Workshop coding, modeling and control scheme will be addressed and discussed. The system is then tested using a wellknown state feedback controller to verify its functionality.
Abstract: In this paper motion analysis on a winding
stair-climbing is investigated using our proposed rotational arm type
of robotic wheelchair. For now, the robotic wheelchair is operated in
an open mode to climb winding stairs by a dynamic turning, therefore,
the dynamics model is required to ensure a passenger-s safety.
Equations of motion based on the skid-steering analysis are developed
for the trajectory planning and motion analysis on climbing winding
stairs. Since the robotic wheelchair must climb a winding staircase
stably, the winding trajectory becomes a constraint equation to be
followed, and the Baumgarte-s method is used to solve for the
constrained dynamics equations. Experimental results validate the
behavior of the prototype as it climbs a winding stair.
Abstract: This paper presents design features of a rescue robot, named CEO Mission II. Its body is designed to be the track wheel type with double front flippers for climbing over the collapse and the rough terrain. With 125 cm. long, 5-joint mechanical arm installed on the robot body, it is deployed not only for surveillance from the top view but also easier and faster access to the victims to get their vital signs. Two cameras and sensors for searching vital signs are set up at the tip of the multi-joint mechanical arm. The third camera is at the back of the robot for driving control. Hardware and software of the system, which controls and monitors the rescue robot, are explained. The control system is used for controlling the robot locomotion, the 5-joint mechanical arm, and for turning on/off devices. The monitoring system gathers all information from 7 distance sensors, IR temperature sensors, 3 CCD cameras, voice sensor, robot wheels encoders, yawn/pitch/roll angle sensors, laser range finder and 8 spare A/D inputs. All sensors and controlling data are communicated with a remote control station via IEEE 802.11b Wi-Fi. The audio and video data are compressed and sent via another IEEE 802.11g Wi-Fi transmitter for getting real-time response. At remote control station site, the robot locomotion and the mechanical arm are controlled by joystick. Moreover, the user-friendly GUI control program is developed based on the clicking and dragging method to easily control the movement of the arm. Robot traveling map is plotted from computing the information of wheel encoders and the yawn/pitch data. 2D Obstacle map is plotted from data of the laser range finder. The concept and design of this robot can be adapted to suit many other applications. As the Best Technique awardee from Thailand Rescue Robot Championship 2006, all testing results are satisfied.
Abstract: Bicycle configuration is not as large as those of motorcycles or automobiles, while it indeed composes a complicated dynamic system. People-s requirements on comfortability, controllability and safety grow higher as the research and development technologies improve. The shock absorber affects the vehicle suspension performances enormously. The absorber takes the vibration energy and releases it at a suitable time, keeping the wheel under a proper contact condition with road surface, maintaining the vehicle chassis stability. Suspension design for mountain bicycles is more difficult than that of city bikes since it encounters dynamic variations on road and loading conditions. Riders need a stiff damper as they exert to tread on the pedals when climbing, while a soft damper when they descend downhill. Various switchable shock absorbers are proposed in markets, however riders have to manually switch them among soft, hard and lock positions. This study proposes a novel design of the bicycle shock absorber, which provides automatic smooth tuning of the damping coefficient, from a predetermined lower bound to theoretically unlimited. An automatic quick releasing valve is involved in this design so that it can release the peak pressure when the suspension fork runs into a square-wave type obstacle and prevent the chassis from damage, avoiding the rider skeleton from injury. This design achieves the automatic tuning process by innovative plunger valve and fluidic passage arrangements without any electronic devices. Theoretical modelling of the damper and spring are established in this study. Design parameters of the valves and fluidic passages are determined. Relations between design parameters and shock absorber performances are discussed in this paper. The analytical results give directions to the shock absorber manufacture.
Abstract: A novel design of two-wheeled robotic vehicle with moving payload is presented in this paper. A mathematical model describing the vehicle dynamics is derived and simulated in Matlab Simulink environment. Two control strategies were developed to stabilise the vehicle in the upright position. A robust Proportional- Integral-Derivative (PID) control strategy has been implemented and initially tested to measure the system performance, while the second control strategy is to use a hybrid fuzzy logic controller (FLC). The results are given on a comparative basis for the system performance in terms of disturbance rejection, control algorithms robustness as well as the control effort in terms of input torque.
Abstract: Wheeled Mobile Robots (WMRs) are built with their
Wheels- drive machine, Motors. Depend on their desire design of
WMR, Technicians made used of DC Motors for motion control. In
this paper, the author would like to analyze how to choose DC motor
to be balance with their applications of especially for WMR.
Specification of DC Motor that can be used with desire WMR is to
be determined by using MATLAB Simulink model. Therefore, this
paper is mainly focus on software application of MATLAB and
Control Technology. As the driving system of DC motor, a
Peripheral Interface Controller (PIC) based control system is
designed including the assembly software technology and H-bridge
control circuit. This Driving system is used to drive two DC gear
motors which are used to control the motion of WMR. In this
analyzing process, the author mainly focus the drive system on
driving two DC gear motors that will control with Differential Drive
technique to the Wheeled Mobile Robot . For the design analysis of
Motor Driving System, PIC16F84A is used and five inputs of sensors
detected data are tested with five ON/OFF switches. The outputs of
PIC are the commands to drive two DC gear motors, inputs of Hbridge
circuit .In this paper, Control techniques of PIC
microcontroller and H-bridge circuit, Mechanism assignments of
WMR are combined and analyzed by mainly focusing with the
“Modeling and Simulink of DC Motor using MATLAB".
Abstract: The challenge for software development house in
Bangladesh is to find a path of using minimum process rather than CMMI or ISO type gigantic practice and process area. The small and medium size organization in Bangladesh wants to ensure minimum
basic Software Process Improvement (SPI) in day to day operational
activities. Perhaps, the basic practices will ensure to realize their company's improvement goals. This paper focuses on the key issues in basic software practices for small and medium size software
organizations, who are unable to effort the CMMI, ISO, ITIL etc. compliance certifications. This research also suggests a basic software process practices model for Bangladesh and it will show the mapping of our suggestions with international best practice. In this IT
competitive world for software process improvement, Small and medium size software companies that require collaboration and
strengthening to transform their current perspective into inseparable global IT scenario. This research performed some investigations and analysis on some projects- life cycle, current good practice, effective approach, reality and pain area of practitioners, etc. We did some
reasoning, root cause analysis, comparative analysis of various
approach, method, practice and justifications of CMMI and real life. We did avoid reinventing the wheel, where our focus is for minimal
practice, which will ensure a dignified satisfaction between
organizations and software customer.
Abstract: This paper presents an environmental and technoeconomic
evaluation of light duty vehicles in Iran. A comprehensive
well-to-wheel (WTW) analysis is applied to compare different
automotive fuel chains, conventional internal combustion engines and
innovative vehicle powertrains. The study examines the
competitiveness of 15 various pathways in terms of energy
efficiencies, GHG emissions, and levelized cost of different energy
carriers. The results indicate that electric vehicles including battery
electric vehicles (BEV), fuel cell vehicles (FCV) and plug-in hybrid
electric vehicles (PHEV) increase the WTW energy efficiency by
54%, 51% and 46%, respectively, compared to common internal
combustion engines powered by gasoline. On the other hand,
greenhouse gas (GHG) emissions per kilometer of FCV and BEV
would be 48% lower than that of gasoline engines. It is concluded
that BEV has the lowest total cost of energy consumption and
external cost of emission, followed by internal combustion engines
(ICE) fueled by CNG. Conventional internal combustion engines
fueled by gasoline, on the other hand, would have the highest costs.
Abstract: In this paper, we are interested in attitude control of a satellite, which using wheels of reaction, by state feedback. First, we develop a method allowing us to put the control and its integral in the state-feedback form. Then, by using the theorem of Gronwall- Bellman, we put the sufficient conditions so that the nonlinear system modeling the satellite is stabilisable and observed by state feedback.
Abstract: Electric vehicles are considered as technology which
can significantly reduce the problems related to road transport such
as increasing GHG emissions, air pollutions and energy import
dependency.
The core objective of this paper is to analyze the current energetic,
ecological and economic characteristics of different types of electric
vehicles.
The major conclusions of this analysis are: The high investments
cost are the major barrier for broad market breakthrough of battery
electric vehicles and fuel cell vehicles. For battery electric vehicles
also the limited driving range states a key obstacle. The analyzed
hybrids could in principle serve as a bridging technology. However,
due to their tank-to-wheel emissions they cannot state a proper
solution for urban areas.
Finally, the most important perception is that also battery electric
vehicles and fuel cell vehicles are environmentally benign solution if
the primary fuel source is renewable.
Abstract: This paper presents modern vibration signalprocessing
techniques for vehicle gearbox fault diagnosis, via the
wavelet analysis and the Squared Envelope (SE) technique. The
wavelet analysis is regarded as a powerful tool for the detection of
sudden changes in non-stationary signals. The Squared Envelope
(SE) technique has been extensively used for rolling bearing
diagnostics. In the present work a scheme of using the Squared
Envelope technique for early detection of gear tooth pit. The pitting
defect is manufactured on the tooth side of a fifth speed gear on the
intermediate shaft of a vehicle gearbox. The objective is to
supplement the current techniques of gearbox fault diagnosis based
on using the raw vibration and ordered signals. The test stand is
equipped with three dynamometers; the input dynamometer serves as
the internal combustion engine, the output dynamometers introduce
the load on the flanges of output joint shafts. The gearbox used for
experimental measurements is the type most commonly used in
modern small to mid-sized passenger cars with transversely mounted
powertrain and front wheel drive; a five-speed gearbox with final
drive gear and front wheel differential. The results show that the
approaches methods are effective for detecting and diagnosing
localized gear faults in early stage under different operation
conditions, and are more sensitive and robust than current gear
diagnostic techniques.
Abstract: Approximate tandem repeats in a genomic sequence are
two or more contiguous, similar copies of a pattern of nucleotides.
They are used in DNA mapping, studying molecular evolution
mechanisms, forensic analysis and research in diagnosis of inherited
diseases. All their functions are still investigated and not well
defined, but increasing biological databases together with tools for
identification of these repeats may lead to discovery of their specific
role or correlation with particular features. This paper presents a new
approach for finding approximate tandem repeats in a given sequence,
where the similarity between consecutive repeats is measured using
the Hamming distance. It is an enhancement of a method for finding
exact tandem repeats in DNA sequences based on the Burrows-
Wheeler transform.
Abstract: As the electrical power industry is restructured, the electrical power exchange is becoming extended. One of the key information used to determine how much power can be transferred through the network is known as available transfer capability (ATC). To calculate ATC, traditional deterministic approach is based on the severest case, but the approach has the complexity of procedure. Therefore, novel approach for ATC calculation is proposed using cost-optimization method in this paper, and is compared with well-being method and risk-benefit method. This paper proposes the optimal transfer capability of HVDC system between mainland and a separated island in Korea through these three methods. These methods will consider production cost, wheeling charge through HVDC system and outage cost with one depth (N-1 contingency)
Abstract: In this study, a robust intelligent backstepping tracking control (RIBTC) system combined with adaptive output recurrent cerebellar model articulation control (AORCMAC) and H∞ control technique is proposed for wheeled inverted pendulums (WIPs) real-time control with exact system dynamics unknown. Moreover, a robust H∞ controller is designed to attenuate the effect of the residual approximation errors and external disturbances with desired attenuation level. The experimental results indicate that the WIPs can stand upright stably when using the proposed RIBTC.
Abstract: An exploratory computational investigation using
RANS & URANS was carried out to understand the aerodynamics
around an isolatedsingle rotating wheel with decreasing ground
proximity. The wheel was initially modeled in free air conditions,
then with decreasing ground proximity and increased yaw angle with
rotational speeds. Three speeds of rotation were applied to the wheel
so that the effect of different angular velocities can be investigated. In
addition to rotation, three different yaw angles were applied to the
rotating wheel in order to understand how these two variables
combined affect the aerodynamic flow field around the wheel.
Abstract: In this paper, a Smart Home Service Robot, McBot II,
which performs mess-cleanup function etc. in house, is designed much
more optimally than other service robots. It is newly developed in
much more practical system than McBot I which we had developed
two years ago. One characteristic attribute of mobile platforms
equipped with a set of dependent wheels is their omni- directionality
and the ability to realize complex translational and rotational
trajectories for agile navigation in door. An accurate coordination of
steering angle and spinning rate of each wheel is necessary for a
consistent motion. This paper develops trajectory controller of
3-wheels omni-directional mobile robot using fuzzy azimuth estimator.
A specialized anthropomorphic robot manipulator which can be
attached to the housemaid robot McBot II, is developed in this paper.
This built-in type manipulator consists of both arms with 3 DOF
(Degree of Freedom) each and both hands with 3 DOF each. The
robotic arm is optimally designed to satisfy both the minimum
mechanical size and the maximum workspace. Minimum mass and
length are required for the built-in cooperated-arms system. But that
makes the workspace so small. This paper proposes optimal design
method to overcome the problem by using neck joint to move the arms
horizontally forward/backward and waist joint to move them
vertically up/down. The robotic hand, which has two fingers and a
thumb, is also optimally designed in task-based concept. Finally, the
good performance of the developed McBot II is confirmed through
live tests of the mess-cleanup task.
Abstract: In this paper an alternative visualisation approach of
the wake behind different vehicle body shapes with simplified and
fully-detailed underbody has been proposed and analysed. This
allows for a more clear distinction among the different wake regions.
This visualisation is based on a transformation of the cartesian
coordinates of a chosen wake plane to polar coordinates, using as
filter velocities lower than the freestream. This transformation
produces a polar wake plot that enables the division and
quantification of the wake in a number of sections. In this paper,
local drag has been used to visualise the drag contribution of the flow
by the different sections. Visually, a balanced wake can be observed
by the concentric behaviour of the polar plots. Alternatively,
integration of the local drag of each degree section as a ratio of the
total local drag yields a quantifiable approach of the wake uniformity,
where different sections contribute equally to the local drag, with the
exception of the wheels.