29 research outputs found
Integrated inpection of sculptured surface products using machine vision and a coordinate measuring machine
In modem manufacturing technology with increasing automation of manufacturing processes
and operations, the need for automated measurement has become much more apparent.
Computer measuring machines are one of the essential instruments for quality control and
measurement of complex products, performing measurements that were previously laborious
and time consuming. Inspection of sculptured surfaces can be time consuming since, for exact
specification, an almost infinite number of points would be required. Automated measurement
with a significant reduction of inspected points can be attempted if prior knowledge of the part
shape is available. The use of a vision system can help to identify product shape and features but,
unfortunately, the accuracy required is often insufficient. In this work a vision system used with
a Coordinate Measuring Machine (CMM), incorporating probing, has enabled fast and accurate
measurements to be obtained. The part features have been enhanced by surface marking and a
simple 2-D vision system has been utilised to identify part features. In order to accurately identify
all parts of the product using the 2-D vision system, a multiple image superposition method
has been developed which enables 100 per cent identification of surface features. A method has
been developed to generate approximate 3-D surface position from prior knowledge of the product
shape.
A probing strategy has been developed which selects correct probe angle for optimum accuracy
and access, together with methods and software for automated CMM code generation. This has
enabled accurate measurement of product features with considerable reductions in inspection
time.
Several strategies for the determination and assessment of feature position errors have been investigated
and a method using a 3-D least squares assessment has been found to be satisfactory.
A graphical representation of the product model and errors has been developed using a 3-D solid
modelling CAD system. The work has used golf balls and tooling as the product example
Statistical point cloud model to investigate measurement uncertainty in coordinate metrology
In this work an approach to investigate measurement uncertainty in coordinate metrology is presented, based on fitting Gaussian random fields to high-density point clouds produced by measurement repeats. The fitted field delivers a depiction of the spatial distribution of random measurement error over a part geometry, and can incorporate local bias information through further measurement or with the use of an external model to obtain a complete, spatial uncertainty map. The statistical model also allows the application of Monte Carlo simulation to investigate how error propagates through the data processing pipeline ultimately affecting the determination of features of size and the verification of conformance to specifications. The proposed approach is validated through application to simulated test cases involving known measurement error, and then applied to a real part, measured with optical and contact technologies. The results indicate the usefulness of the approach to estimate measurement uncertainty and to investigate performance and behaviour of measurement solutions applied to the inspection and verification of industrial parts. The approach paves the way for the implementation of automated measurement systems capable of self-assessment of measurement performance
Robot Manipulators
Robot manipulators are developing more in the direction of industrial robots than of human workers. Recently, the applications of robot manipulators are spreading their focus, for example Da Vinci as a medical robot, ASIMO as a humanoid robot and so on. There are many research topics within the field of robot manipulators, e.g. motion planning, cooperation with a human, and fusion with external sensors like vision, haptic and force, etc. Moreover, these include both technical problems in the industry and theoretical problems in the academic fields. This book is a collection of papers presenting the latest research issues from around the world
Non contact surface metrology in a hazardous environment
The EFDA-JET tokamak is an experimental fusion device researching fusion as a means
of energy production. Inside the toroidal vessel, plasma with temperature in excess of
100 million degrees Celsius is generated and constrained by high power magnetic fields.
Additional protection is provided by tiles which clad the inside of the machine. As part
of a major upgrade existing heat protective tiles are to be replaced with an advanced
design, and renewed interest has been shown in dimensional measurement of the
surface.
Measurement must occur during shutdown periods where temperature and pressure are
at ambient levels. Manned entry is not permissible and all work should be performed
remotely. To avoid contamination which could affect the fusion reaction and
experimental results, contact with the measurement surface is not permitted.
This work assesses non-contact surface measurement technologies, along with standards
and guidelines for dimensional surface measurement. Existing measurement test
artefacts do not offer the required surface finish and features, so specific test artefacts
have been designed and produced. These artefacts are traceable to the national length
standard, as traceability is a pre-requisite to evaluate accuracy.
Exploratory tests highlighted two technologies for further investigation, laser
triangulation and white light fringe projection. Two commercially available, state-ofthe-
art examples of each technology have been evaluated using a processing method
developed to highlight performance in key areas relevant to EFDA-JET. These areas
include quantitative assessments of the effect of surface angle on measurement quality,
the effect of depth of field for fringe projection systems and the ability of technologies
to record gap and flush from tens of micrometres to millimetres.
Tests enable a user to begin to assess the impact the measurement system has on the
measurement result, how different technologies and systems used alone or in
combination may resolve or compound erroneous results, clarifying or disrupting the
meaning of results
Optimization of Operation Sequencing in CAPP Using Hybrid Genetic Algorithm and Simulated Annealing Approach
In any CAPP system, one of the most important process planning functions is selection of the operations and corresponding machines in order to generate the optimal operation sequence. In this paper, the hybrid GA-SA algorithm is used to solve this combinatorial optimization NP (Non-deterministic Polynomial) problem. The network representation is adopted to describe operation and sequencing flexibility in process planning and the mathematical model for process planning is described with the objective of minimizing the production time. Experimental results show effectiveness of the hybrid algorithm that, in comparison with the GA and SA standalone algorithms, gives optimal operation sequence with lesser computational time and lesser number of iterations
Optimization of Operation Sequencing in CAPP Using Hybrid Genetic Algorithm and Simulated Annealing Approach
In any CAPP system, one of the most important process planning functions is selection of the operations and corresponding machines in order to generate the optimal operation sequence. In this paper, the hybrid GA-SA algorithm is used to solve this combinatorial optimization NP (Non-deterministic Polynomial) problem. The network representation is adopted to describe operation and sequencing flexibility in process planning and the mathematical model for process planning is described with the objective of minimizing the production time. Experimental results show effectiveness of the hybrid algorithm that, in comparison with the GA and SA standalone algorithms, gives optimal operation sequence with lesser computational time and lesser number of iterations
Autonomous Navigation of Automated Guided Vehicle Using Monocular Camera
This paper presents a hybrid control algorithm for Automated Guided Vehicle (AGV) consisting of two independent control loops: Position Based Control (PBC) for global navigation within manufacturing environment and Image Based Visual Servoing (IBVS) for fine motions needed for accurate steering towards loading/unloading point. The proposed hybrid control separates the initial transportation task into global navigation towards the goal point, and fine motion from the goal point to the loading/unloading point. In this manner, the need for artificial landmarks or accurate map of the environment is bypassed. Initial experimental results show the usefulness of the proposed approach.COBISS.SR-ID 27383808
Autonomous Navigation of Automated Guided Vehicle Using Monocular Camera
This paper presents a hybrid control algorithm for Automated Guided Vehicle (AGV) consisting of two independent control loops: Position Based Control (PBC) for global navigation within manufacturing environment and Image Based Visual Servoing (IBVS) for fine motions needed for accurate steering towards loading/unloading point. The proposed hybrid control separates the initial transportation task into global navigation towards the goal point, and fine motion from the goal point to the loading/unloading point. In this manner, the need for artificial landmarks or accurate map of the environment is bypassed. Initial experimental results show the usefulness of the proposed approach.COBISS.SR-ID 27383808
Applicable Solutions in Non-Linear Dynamical Systems
From Preface: The 15th International Conference „Dynamical Systems - Theory and Applications” (DSTA 2019, 2-5 December, 2019, Lodz, Poland) gathered a numerous group of outstanding scientists and engineers who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without great effort of the staff of the Department of Automation, Biomechanics and Mechatronics of the Lodz University of Technology. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our event was attended by over 180 researchers from 35 countries all over the world, who decided to share the results of their research and experience in different fields related to dynamical systems. This year, the DSTA Conference Proceedings were split into two volumes entitled „Theoretical Approaches in Non-Linear Dynamical Systems” and „Applicable Solutions in Non-Linear Dynamical Systems”. In addition, DSTA 2019 resulted in three volumes of Springer Proceedings in Mathematics and Statistics entitled „Control and Stability of Dynamical Systems”, „Mathematical and Numerical Approaches in Dynamical Systems” and „Dynamical Systems in Mechatronics and Life Sciences”. Also, many outstanding papers will be recommended to special issues of renowned scientific journals.Cover design: Kaźmierczak, MarekTechnical editor: Kaźmierczak, Mare