Mechatronics and Machine Vision in
Practice, 2006
Toowoomba December 5-7
Day 1. Tuesday 5 December
Opening address 9.45 - 10.00
Viewpoint 10.00 - 10.30
018: Click on number to see the full text.
Coordination in Mechatronic Engineering Work
James Trevelyan
School of Mechanical Engineering, The University of Western
Australia
Abstract
This paper shows that little has been written on the roles that people
actually perform in the course of mechatronics engineering work.
The paper reports empirical results of interviews with
several engineers working in mechatronics: this is part of a larger
study of engineering work in several disciplines. The paper
argues that coordinating the work of other people is the most
significant working role, both in mechatronic engineering and also
other engineering disciplines. This role has not been explicitly
identified before. While coordination appears to be a generic
non-technical role, close examination reveals that technical knowledge
is very important for effective coordination in engineering work.
The coordination role is not mentioned in engineering course
accreditation criteria. The absence of explicit references to this role
in previous literature suggests that the research methods used for this
study could provide better guidance for engineering educators on course
requirements.
Education 1 11.00 - 12.30
Design and Implementation of a four rotor helicopter and study of
its
stability
J. Toledo, M. Sigut, L. Acosta, J. Felipe, S. Torres and E. J.
Gonzalez
Department of Systems Engineering and Control and Computer
Architecture,
University of La Laguna, Spain
Abstract
In this paper, a study of a four rotor helicopter prototype control is
presented. Firstly, the different aspects of the prototype construction
will be described, making an special emphasis in the mechanics, the
design of the sensorial and actuation systems and the prototype
control. Next, the formalism of the lifting and inverse lifting
operators will be presented. As it will be shown, they can be applied
to this multifrequency system in order to allow to use a simple lineal
method to analytically determine the closed-loop system stability.
Emergent Behaviour Real-time Programming of a Six-Legged
Omni-Directional Mobile Robot: Planning of Viennese Waltz behaviour
Frank Nickols
Mechanical Engineering Dept.
Dhofar University, Salalah,
Sultanate of Oman, Middle East.
Abstract
Viennese waltz behaviour means combined translation and rotation. This
motion is applied to a six-legged omnidirectional robot. Such behaviour
is highly useful because it represents generalised omnidirectional
motion of a vehicle in a ground plane. The motion is similar to
programming a mobile Stewart platform and is complex problem to program
into a six-legged robot especially in real-time. This paper presents a
plan to achieve such motion based on a sun and planet wheel model.
Keywords: Emergent behaviour,
combined rotation and translation,
Viennese waltz behaviour, robot omnidirectional motion, continuous
computation, biological computation.
QTAR: Quad-Thrust Aerial Robot
Joshua N Portlock and Samuel N Cubero
Curtin University of Technology, Perth, Western Australia
Abstract
The Quad Thrust Aerial Robot (QTAR) is a low-cost
quadrotor Vertical Take-Off and Landing (VTOL) Unmanned Aerial Vehicle
(UAV). The onboard attitude estimation and control system allows for
safe and intuitive remote piloting for various aerial imaging
applications, both indoors and out. This paper presents the design and
development of the QTAR, including the attitude estimation using
low-cost inertial sensors and employing a novel Jerk adaptive filtering
technique.
Medical 1 2.00 - 3.00
Development of an Intelligent Physiotherapy System
S.L. Chen, W.B. Lai, T.H. Lee, K.K. Tan
Dept of Electrical and Computer Engineering, National University of
Singapore
Abstract:
This paper focuses on the development of a portable Intelligent
Physiotherapy system. As this system makes use of computer control and
programming, it is able to provide a higher level of safety,
intelligence, convenience, customization, and portability and enhanced
human-equipment interaction compared to many existing physiotherapy
equipment such as gym machines and weights. It is also able to provide
objective feedback of the physiotherapy patient’s routine; this can
lead to more effective treatments as the physiotherapist can make use
of the feedback in additional to his professional judgment when
analyzing the patient’s condition. An objective test on the
ability of the patient to carry out his routine may also be useful to
insurance companies in evaluating the extent of the injury suffered by
the patient. Outside the realm of medical treatment, the versatility of
the Intelligent Physiotherapy system also makes it ideal as an exercise
machine for athletes who want to keep track of their training
progresses.
A Display Framework for Presenting Information from a Visual
Prosthesis
Jason Dowling1 , Wageeh Boles and Anthony Maeder2
1Queensland University of Technology, Brisbane, Australia
2e-Health Research Centre / CSIRO ICT Centre, Brisbane
Australia.
Abstract
In this paper a novel framework for the dynamic presentation of
information to a visual prosthesis recipient is presented. This
framework includes the main factors which impact on blind
mobility. These factors include the current context, scene
properties, task undertaken, available sensory information, and
environmental factors , in addition to human factors (such as level of
training) and prosthesis technology (for example, camera and
electrode array technology).
The electrical stimulation of a component of the human visual system
can result in the perception of blobs of light (or phosphenes) in
totally blind patients. By stimulating an array of closely
aligned electrodes it is possible for a blind person to perceive very
low-resolution phosphene images. Using this approach, a number of
international research groups are working toward developing multiple
electrode systems (called visual prostheses or Artificial Human Vision
(AHV) systems) to provide a phosphene-based substitute for normal human
vision. Computer vision methods provide a critical link between
the camera and electrode array of an effective visual prothesis.
Medical 2 3.30 - 5.00
An autonomous surgical robot applied in practice.
P.N.Brett1, R.P.Taylor1, D.Proops2,
M.V.Griffiths3 and C.Coulson1
1Aston University, Birmingham UK
2Queen Elizabeth Hospital Birmingham, UK
3Saint Michaels Hospital, Bristol, UK
Abstract
Robotics in surgery is a field that has been explored over two decades
leading to a series of commercially available systems. The
systems developed have demonstrated the application of mechatronics in
challenging working conditions in practice. The aim is to apply
the benefits of such machine systems to achieve precision in placing
tool points at the position of the target tissue interface.
Safety, sterility, surgical practice, the operating environment and
operating protocol are significant driving factors to deriving
acceptable solutions.
Registration between tool path and the tissues of the patient are often
achieved by localising patient scan data with the machine. As such
surgical robots have not been autonomous and have been working on paths
and regions defined from pre-operative scan data. In this paper the
application of the first autonomous surgical robot is described applied
to a microsurgical task. The robotic micro-drill was first used
in cochleostomy and moves on a linear tool path with respect to
tissue-tool interaction encountered and determined from the sensory
information. The departure from the traditional approach of
pre-defining motion is necessary at the scale of micro-surgical tool
action where tissue deflection in response to applied loads is regarded
significant. Earlier versions of this device have been reported
in terms of the sensory approach. Here the emphasis is towards
the application in clinical trials of the final device. This
paper describes the purpose and design with respect to the procedure,
surgical protocol, operating room environment, and the performance
achieved by the mechatronic device in practice.
Intelligent Approach to Cordblood Collection
S. Chen, K.K. Tan, T.H. Lee, S. Huang and K.Z. Tang
Dept of Electrical and Computer Engineering, National University of
Singapore
Abstract
In this paper, the development of an intelligent umbilical cord blood
(UCB) collection system is presented. The hardware architecture,
software development platform, user interface, and all constituent
control components will be elaborated on in the paper. The overall
control system is comprehensive, comprising of various selected control
and instrumentation components, integrated within a configuration of
hardware architecture centred around a dSPACE DS1002 Digital Signal
Processing (DSP) board.
Deformable Object Simulation with Fluid Model
Yongmin Zhong1, Bijan Shirinzadeh1 and Julian
Smith2
1Robotics & Mechatronics Research Laboratory,
Department of Mechanical Engineering, Monash University, Australia
2Department of Surgery, Monash Medical Centre,
Monash University, Australia
Abstract
This paper presents a new methodology for deformable object simulation
by drawing an analogy between ideal fluid and elastic deformation. The
potential energy stored due to a deformation caused by an external
force is calculated and treated as the source injected into the fluid
system, as described by the energy conservation law. A fluid based
methodology is proposed for soft object deformation. An improved fluid
model is developed for propagating the energy generated by the external
force among mass points. A method is presented to derive the internal
forces from the potential energy distribution. This methodology can not
only deal with large-range deformation, but it can also accommodate
isotropic, anisotropic and inhomogeneous materials through simply
changing the fluid coefficients. Examples are presented to demonstrate
the efficiency of the proposed methodology.
Day 2 - Wednesday 6 December
Other Techniques 1 9.00 –
11.30
Sensing Objects on a Belt Conveyor Using an Ultrasonic Rangefinder
Array and Neural Net Based Data Processing
Changwoo Ha and Yongtae Do
School of Electronic Engineering, Daegu University, 712-714, Korea
Abstract
This paper describes the construction and operation of a sensor system
using multiple ultrasonic rangefinders to measure the position of a
moving object on a belt conveyor. Nine Polaroid transducers are
positioned in a 2D matrix array. The output of the sensor system is a
sparse range image of five-pixel width. A neural network is employed to
improve the image. The feedforward multilayer network is trained
automatically using the data collected by a vision system for bar-coded
boxes of known sizes. In an experiment of measuring the centroids of
objects, the use of a neural network resulted in about 10% accuracy
improvement.
A Power and Bandwidth Efficient Remote Wireless Video Surveillance
System Using Joint Source-Channel Coding
Wei Xiang
Faculty of Engineering and Surveying
University of Southern Queensland
Toowoomba, QLD 4350, Australia
Abstract
A novel wireless remote video surveillance system based on joint
source-channel coding is proposed in this paper. The proposed system
exhibits superior bandwidth and power efficiency thanks to the adoption
of the proposed iteratively decodable variable-length codes (IDVLCs).
An experimental platform was built and simulation results were shown to
demonstrate the superior performance of the proposed video surveillance
system in terms of both objective and subjective measurements.
Direct Kinematics of 3DOF Planar Parallel Mechanisms: A Discussion
Denny Oetomo1, Hwee Choo Liaw1, Gursel Alici2,
Bijan Shirinzadeh1, and
Yongmin Zhong1.
1Department of Mechanical Engineering,
Monash University, Clayton, VIC 3800, Australia.
2 School of Mechanical, Materials, and Mechatronics
Engineering,
University of Wollongong, NSW 2522, Australia.
Abstract
This paper presents the direct kinematic solutions of 3DOF planar
parallel mechanisms, specifically of the 3RRR mechanism. The direct
kinematic problem of the mechanism generally results in a polynomial
solution. To obtain an analytical (closed-form) solution, it is
necessary for the polynomial to be of degree 4 or less. This paper
presents a special configuration that reduces the polynomial solution
to a 4th degree. This special configuration further decouples the
direct kinematics of the position and the orientation of the
end-effector into two cascaded quadratic equations. A numerical
example is carried out to verify the results of this simplification.
The existence of the closed-form solution would increase the accuracy
of the direct kinematic solution and improve computational efficiency,
as numerical iterative method is not required. This result provides an
efficient computational method for a very useful configuration of
planar parallel manipulators.
Modelling pneumatic muscles as hydraulic muscles for use as an
underwater actuator
Kenneth, K.K.Ku and Robin Bradbeer
Department of Electronic Engineering, City University of Hong Kong,
Kowloon, Hong Kong
Abstract
Pneumatic muscles have been used for a number of years as actuators in
robotic systems, usually for those that mimic human actions. They are
most commonly used in systems designed to aid physically handicapped
people. It has become clear that if the muscles could be powered
hydraulically instead of pneumatically, then they would provide a very
efficient actuator for underwater use. This paper looks at preliminary
results of such an application.
Vision Techniques 1 11.30 -
12.30
Advanced 3D Imaging Technology for Autonomous Manufacturing Systems
A. Pichler, H. Bauer, C. Eberst, C. Heindl, J. Minichberger
PROFACTOR Research, Im Stadtgut A2, 4407 Steyr-Gleink, Austria.
Abstract.
Today’s markets and economies are becoming increasingly volatile
and unpredictable; they are changing radically and even the innovation
speed is accelerating. Manufacturing and production technology and
systems must keep pace with this trend. To counter these
challenging prospects, technologies enabling autonomous production
systems are needed. The paper gives an overview of a novel innovative
vision system embedded in manufacturing applications. The system is
able to handle (1) unknown products, (2) in-available data, (3) large
disturbances and deviations (shape, position, or even part type) and
(4) even very small lot-sizes. The concept foresees a full integration
into production technology. Products to be processed are passed through
a flexible 3D sensor cell. In principle, the 3D imaging process is
based on subsequent modules: (1) 3D data retrieval, (2) 3D
reconstruction and (3) 3D data interpretation. The proposed system
adapts its sensor system to arbitrary product geometry and builds a 3D
world model of the task space using fast and robust 3D object
recognition system. Having a flexible 3D imaging system paired with
automatic process planners, the approach has proven to be a promising
alternative to conventional teach-in and OLP based programming and is
feasible especially for highly variant, low volume
parts. Robust 3D imaging technology contributes to
the realization of autonomous manufacturing systems if part or scene
complexity is very high.
Keywords: 3D imaging,
object recognition, robotic, process
planning.
A vision system for depth perception that uses inertial sensing and
motion parallax
V Bečanović and XB Wang
Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu,
Kitakyushu,
Japan.
Abstract.
A vision system is proposed that calculates the distance to an object
based on geometrical relations of perceived object point and observer
motion. The system will in the reference frame of the observer give
absolute distance estimates to objects that are static or moving with
close to constant velocity. The distance algorithm was validated in a
ray tracing Monte-Carlo simulation and a corresponding experiment was
also successfully performed. In the experiment the perceived object
motion was acquired with a contrast enhancing silicon retina type of
imager and the motion of the observer was estimated with a low cost
inertial sensor. The experiment was performed with the vision system
accelerated with the help of gravity and was tested for static objects
in a range from 0.5 to 3.0 meters showing promising results.
Education 2 2.00 - 3.00
The Hong Kong Underwater Robot Challenge
Robin Bradbeer
Director, Hoi Ha Wan Marine Science and Engineering Laboratory,
Department of Electronic Engineering, City University of Hong Kong,
Kowloon Tong, Hong Kong
Abstract
Marine conservation is usually a subject that is taught to life
sciences students at secondary schools. As such, those students
interested in marine conservation tend to come from biology and related
subjects. The project described in this paper aims to bring the
concepts of using technology for marine conservation to those students
of a more technological background. The great interest in the ocean
surrounding Hong Kong led to the idea of having the students build
underwater robots, similar to those of the MATE/MTS competition. The
parts kit includes motors, wire, propellers and switches, and the
robots’ performance is tested in a pool by carrying out tasks under
remote control. This paper presents an analysis of the event as
well as the results of taking part in the World Finals in Houston in
June 2006.
Project-oriented low cost autonomous underwater vehicle with
servo-visual control for Mechatronics Curricula
C. A. Cruz-Villar1, V. Parra-Vega2, and
A. Rodriguez-Angeles1
1Center for Research and Advanced Studies
(CINVESTAV
I.P.N.), Electrical Engineering Department, Mechatronics Group
2CINVESTAV I.P.N., Saltillo, Robotics and Advanced
Manufacture Group
Abstract:
This paper describes a project oriented Autonomous Underwater
Vehicle (AUV) that integrates three different courses in a
Mechatronics Master Sciences academic program. The postgraduate program
in Mechatronics at CINVESTAV includes the courses:
Real Time Programming, CAD/CAM/CAE, and Modeling and Simulation of
Mechatronics Systems. The students simultaneously pursue these
three courses that last 14 weeks in two weekly sessions of two hours
each. It is intended that the students develop a final project
per course to apply the acquired knowledge. However during the first
term of 2006, it was proposed to integrate the final project, so that
it involves goals and tasks of the three courses.
For integration purposes it was proposed to take a radio control system
which could be modelled and modified to apply reverse engineering and
real time control. On looking at commercial radio control mobile
systems, a micro submarine was selected as it requires a small working
area and presents challenging issues such as hydrodynamic effects and
under-actuation in some degrees of freedom.
Vision Techniques 2 3.30 – 5.00
Particle size determination in granular images using edge
detection,
with application to agricultural products
Ronald Elunai and Vinod Chandran
Queensland University of Technology
Abstract
A method for determination of grain size from granular textures is
developed. The method is one which at-tempts to capture the graininess
distribution directly from the digital image. It employs classical edge
detection and computes the average distance, or pixel runs, between
successive edges. With Uniform digital image acquisition conditions,
the method can discriminate images with different granularities. Two
experiments were conducted, one with subjective ranking of grain
images, and another experiment for measurement of absolute graininess.
Both experiments reveal the suitability of the method in measuring
granularity and produce results that correlate with perceptual
experiments.
Vision Based Person Tracking and Following in Unstructured
Environments
Mahmoud Tarokh and John Kuo
Department of Computer Science, San Diego State University,
San Diego, CA 92124, USA.
Abstract
The paper describes a method for the detection of a person from the
environment by a vision system, and tracking and following the person
by a robot equipped with a camera. The person detection is
achieved by a technique based on colour and shape recognitions.
Based on the features provided by the visions system, a fuzzy control
scheme is proposed for tracking the person. Four quantities are
controlled, namely, camera pan and tilt, and robot speed and
steering. The software consists of several components for image
processing, low level motor control and high level fuzzy control.
The results of person following are reported for indoor and outdoor
environments using an all-terrain rover on which an articulated camera
and a lap top computer are mounted. These trials include passage
through labs and hallways, moving up steep and winding dirt trails,
traversal over rocky terrain, and person following with incomplete
image and partial occlusion.
Simple, Robust and Accurate Head-Pose Tracking Using a Single Camera
Simon Meers, Koren Ward and Ian Piper
University of Wollongong, Australia.
Abstract
This paper describes an inexpensive, robust method for tracking the
head position and orientation of the user by using a single low-cost
USB camera and infrared light emitting diodes concealed within
spectacle frames worn by the user. Unlike gaze and head-pose tracking
systems which rely on high-resolution stereo cameras and complex image
processing hardware and software to find and track facial features on
the user, the proposed system is able to efficiently locate and track
the head's orientation and distance relative to the camera with little
processing. Due to the infrared light emitting diodes having fixed
geometry, the system does not have to contend with the varying facial
features of different users and therefore does not require any
calibration procedure or training to accommodate different users.
Furthermore, the proposed system is unaffected by varying lighting
conditions and can be used in the dark. Experimental results are
provided demonstrating a head-pose tracking accuracy of within 0.5
degrees when the user is within one meter of the camera. This compares
well with more expensive head tracking systems.
Day 3 - Thursday 7 December
Vision Applications 1 9.00 -
10.30
Millimetre wave radar visualisation system: practical
approach to
transforming mining operations
E. Widzyk-Capehart1, G. Brooker2, S. Scheding2,
A. Maclean2, R.
Hennessy2, C. Lobsey2 and M. Sivadorai1
1CRCMining, The University of Queensland, Brisbane,
Australia
2CRCMining and Australian Centre for Field Robotics,
University of
Sydney, Sydney, Australia
Abstract
This paper describes the development of millimetre-wave frequency
modulated continuous wave radar and its application in the mining
industry. Assessment of various sensors: laser, sonar, visual and
microwave radar, against the mm wave radar sensor proves radar
performance superiority in difficult mining conditions. The
implementation and performance verification of the radar sensor for
range and 3D profiling were undertaken in an underground environment
for stope fill and ore-pass monitoring and in surface mines for
dragline environmental mapping and rope shovel bucket and dig face
imaging. The millimetre wave radar visualisation system development,
testing, on-site applications and the benefits to the mining industry
are hereby discussed.
Minutiae-based Fingerprint Alignment Using Phase Correlation
Weiping Chen and Yongsheng Gao
School of Engineering, Faculty of Engineering and Information
Technology,
Griffith University, Australia
Abstract
Fingerprint alignment is an important step in fingerprint recognition.
The performance of fingerprint recognition relies heavily on the
accuracy of fingerprint alignment. The minutiae-based approach is the
most popular approach in fingerprint alignment. However, most existing
minutiae-based approaches are using additional features (ridge pattern
and nearest minutiae) or reference points (core and delta
points). These approaches need to search for the best
correspondence of pairs to estimate the alignment parameters. The
problem of lost minutiae or spurious minutiae always occurs during the
minutiae detection process. Hence, the corresponding pairs or reference
points may not be found under this condition. This paper proposes a new
minutiae-based fingerprint alignment algorithm using phase correlation.
First, we convert minutiae sets into 2D image spaces called Minutiae
Direction Image (MDI). Then the transformation parameters can be
calculated using phase correlation between two MDIs directly.
Experimental results show that the proposed approach performed well in
aligning fingerprint minutiae sets and greatly improved the economy of
storage space.
Machine Vision for Beer Keg Asset Management
Michael Lees1, Duncan Campbell2, Andrew Keir2
1Foster’s Australia, Yatala Operations
2School of Engineering Systems, Queensland University of
Technology
Abstract
A typical large brewery could have a keg fleet size in the order
of hundreds of thousands. For some breweries, the asset value of this
fleet is second only to fixed plant. The annual rate of attrition
within the fleet can range from 5% to 20%, a sizable figure in dollar
terms with a stainless steel keg costing around USD100. There is a
business case for a keg asset management system that can help to reduce
the annual rate of attrition and supply chain cycle time. Established
solutions such as bar codes and RFID tags are costly as they require a
modification to every keg. The feasibility of a machine vision tracking
system based on the optical character recognition (OCR) of the keg's
existing serial number is explored. With prospective implementation in
the keg filling line, a process is proposed which is based on neural
network OCR. A recognition rate of 97% was achieved for kegs with
non-occluded serial numbers with realistic scope for further
improvement.
Vision Applications 2 11.00 -
12.30
On-the-go machine vision sensing of cotton plant geometric
parameters:
first results
Cheryl McCarthy, Nigel Hancock and Steven Raine
Cooperative Research Centre for Irrigation Futures,
National Centre for Engineering in Agriculture
Faculty of Engineering and Surveying, University of Southern
Queensland, Toowoomba, Australia.
Abstract
Plant geometrical parameters such as internode length (i.e. the
distance between successive branches on the main stem) indicate water
stress in cotton. This paper describes a machine vision system
that has been designed to measure internode length for the purpose of
determining real-time cotton plant irrigation requirements. The
imaging system features an enclosure which continuously traverses the
crop canopy and forces the flexible upper main stem of individual
plants against a glass panel at the front of the enclosure, hence
allowing images of the plant to be captured in a fixed object
plane. Subsequent image processing of selected video sequences
enabled detection of the main stem in 88% of frames. However,
node detection was subject to a high false detection rate due to leaf
edges present in the images. Manual identification of nodes in
the acquired imagery enabled measurement of internode lengths with 3%
standard error.
Visual Position Estimation for Automatic Landing of a Tail Tail-Sitter, Vertical Takeoff and Landing Unmanned Air Vehicle
Allen C. Tsai, Peter W. Gibbens, and R. Hugh Stone
School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney.
Abstract
Vertical Takeoff and Landing (VTOL) Unmanned Air Vehicles (UAV’s)
combine the operational benefit of efficient forward flight with the
capability to land vertically on unprepared sites. Vertical landing in
small spaces does, however, require very precise relative navigation
and guidance. Visual systems promise a very real benefit over systems
like GPS, in that the accuracy of the relative position estimates
should improve as the vehicle gets closer to the landing target. This
paper describes progress toward the development of a visual sensor
system to provide information on aircraft attitude and position
relative to a designated landing target while hovering on
descent. The system combines principles of target recognition
with attitude estimation using perspective projection. These data are
fused with inertial attitude information to assist in the
identification of the lateral and vertical distances to the target for
use in the guidance system. The paper shows preliminary results
of position estimation using image data taken during flight
trails. It compares these results to GPS position estimates and
discusses the relative accuracy.
Machine Vision Application for Machined Components Surface
Roughness
Assessment in the Micro and Nano-Scale Regions
Ghassan A. Al-Kindi1, Bijan Shirinzadeh2 and
Yongmin Zhong2
1Department of Mechanical Engineering, University of
Technology,
Baghdad, Iraq
2Robotics & Mechatronics Research Laboratory,
Department of
Mechanical Engineering, Clayton, VIC 3800, Australia
Abstract
This paper presents a vision-based approach for valid assessment of
surface roughness in both micro-scale and nano-scale regions. To enable
data comparisons, three sets of surface data in the micro-scale and
nano-scale regions are acquired by using a CCD camera, a video-based
optical microscope and a stylus instrument. Data filtering and analysis
procedures are applied to the acquired data. Results for computation of
roughness parameters by using vision data provide adequate values for
assessment of surface roughness in the same manner as the stylus based
technique. No obvious changes in the computed roughness parameter
values are resulted from the micro-scale and nano-scale regions. In the
nano-scale region, a cavity graph technique provides distinguishable
forms of graphs, which tend to more gradual increase of the cavity
percentage to denote the collection of the macro surface details. In
addition, an auto correlation technique applied in the nano-scale
region succeeds to discriminate the surface irregularity relationships
with respect to their periodicity and randomness. The overall acquired
results indicate that vision systems are a valid source of data for
reliable surface roughness evaluation in both micro/nano-scale regions.
The results are very useful in achieving commercial 3D vision based
micro/nano-scale roughness measurement systems for industrial
applications.
Other Techniques 2 2.00 - 3.00
Non-linear Observer for Slip Estimation of Tracked Vehicles
Z.B. Song1, Y.H. Zweiri2, K. Althoefer1
and L.D. Seneviratne1
1Department of Mechanical Engineering,
King's College London,
Strand, London WC2R 2LS, UK.
Telephone: +44 (0)207 848 2236
Email: lakmal.seneviratne@kcl.ac.uk
2Department of Mechanical Engineering,
University of Mu'tah,
Karak, Jordan
Abstract
Slip plays an important role in determining tracked vehicle tractive
forces. Thus accurate estimation of slip is essential in developing
autonomous navigation strategies for unmanned ground vehicles operating
in unprepared terrain.
This paper presents an accurate and robust technique for the estimation
of tracked vehicle slip parameters; the slips of outer and inner tracks
and the slip angle. The technique uses a sliding mode observer (SMO)
with sprocket wheel angular velocities and vehicle trajectory as
inputs, and estimates slip parameters by minimizing the errors between
the predicted trajectory and the measured trajectory. The SMO is based
on a full kinematic model of the tracked vehicle and a Utkin SMO. The
conditions for stability of the SMO are derived using Lyapunov
stability theory. The experimental results show that the slip estimate
using the SMO can accurately capture the trend of measured slip
parameters.
Mobile Robot Navigation using Alpha Level Fuzzy Logic System:
Theoretical and Experimental Investigations
S.Parasuraman1 , V.Ganapathy1, Bijan
Shirinzadeh2, Yongmin Zhong2
1Monash University, Malaysia, 2Monash
University, Australia.
Abstract
In this paper, behavior rule selection or decision-making procedure
incorporating Alpha-level fuzzy logic system is discussed and used for
selecting an appropriate action during mobile robot navigation. In this
methodology, environmental perceptual field is well defined by a set of
control parameters through alpha level intervals of fuzzy sets and
their fuzzy membership value. The expected output control parameters
are also partitioned by alpha level intervals. In the proposed method,
the alpha level threshold maximizes the truth for a particular
behaviour rule that needs to be fired at a time. This methodology
presents the mathematical aspects of resolving conflicts when more than
one context rule of the same kind is in action. This approach provides
a formal methodology for representing and implementing the human expert
heuristic knowledge and perception-based action in mobile robot
navigation. In this approach, the operational strategies of the human
expert driver are transferred via Alpha level fuzzy logic to the robot
navigation in the form of a set of simple conditional statements
composed of linguistic variables. The proposed behavior rule selection
method is validated by real world experiments using active media
pioneer robot and the results are discussed and compared with most
accepted methods.
Short video 3.30
More machine vision applications in the NCEA
John Billingsley
University of Southern Queensland
Abstract
This is a second showing of a video presentation prepared for the ICMT conference in Mexico.
With the trend of computers towards convergence with multimedia
entertainment, tools for vision processing are becoming commonplace.
This has led to the pursuit of a host of unusual applications in the National Centre
for Engineering in Agriculture, in addition to work on vision guidance.
These range from the identification of animal species, through the location of
macadamia nuts as they are harvested and visual tracking for behaviour
analysis of small marsupials to the measurement of the volume of dingo teeth.
Keywords: Agricultural applications, Machine
vision, Shape matching, s-psi.
Vision tutorial 3.45 Mark Dunn, NCEA