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Journal PROCEEDINGS IN MANUFACTURING SYSTEMS |
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ISSN 2343–7472 ISSN-L 2067-9238 |
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Journal PROCEEDINGS IN MANUFACTURING SYSTEMS
□ Volume 11, Issue 3, 2016
· Gabriel FRUMUŞANU, Virgil TEODOR, Sofia TOTOLICI, Nicolae OANCEA, The
interference at the assemblage of cylindrical worm-star wheel gear Basic
research of thermal transfer simulations Manufacturing
systems and passive safety Imitation
learning by following the virtual paths for physical robots · Steffen BUTZER, Sebastian SCHÖTZ, Katharina HAUCK, Rolf STEINHILPER, Maturity
model for evaluation of resource efficiency in manufacturing SMEs · Diana POPESCU, Daniel VLĂSCEANU, Lucian CURSARU, Florin BACIU,
Anton HADĂR, Low-temperature sterilization influence on fused deposition modelling parts · Andrei Mario IVAN, Cezara Georgia COMAN, Adrian Florin NICOLESCU, Comparison
between conventional milling and climb milling in robotic deburring of
plastic parts Gabriel
FRUMUŞANU1, Virgil TEODOR2, Sofia TOTOLICI3,
Nicolae OANCEA4 1), 4) Prof., PhD,
Manufacturing Engineering Department, “Dunărea de Jos” University of
Galaţi, Romania 2) Assoc. Prof., PhD,
Manufacturing Engineering Department, “Dunărea de Jos” University of
Galaţi, Romania 3) Assoc. Prof.,
PhD, Businesses Management Department, “Dunărea de Jos” University of
Galaţi, Romania Abstract: The cylindrical
worm – star wheel gear can be met in practice, for example, in transmissions
with kinematical purpose, or in the construction of single screw compressors.
Despite having a limited applicability, it presents an important advantage,
consisting in the simplicity of its manufacturing. The paper suggests an
analytical solution for finding the interference at the assemblage of
cylindrical worm – star wheel gear, which is an important matter concerning
the design of this type of transmission. The solution lies on a complementary
theorem regarding surfaces enveloping, namely the theorem of plain generating
trajectories family. An analytical algorithm has been developed in MatLab, in
order to implement this solution. A numerical application, which was solved
in a concrete case, is also presented. Key words: cylindrical worm – star wheel gear, assemblage, interference, plain
generating trajectories family, MatLab. Basic
research of thermal transfer simulations Vaclav MAREK1 1) MSc., junior
researcher, Regional Technological Institute, University of West Bohemia,
Pilsen, Czech Republic Abstract: The article summarizes basic research into thermal
transfer simulations. Problems of thermal influence in mechanical systems are
solved there. The first steps focus on matching simple heat-transfer samples
with CAE software. Simple cases are performed in a real environment. Thermal
values are measured. Cases are also solved using CAE software tools.
Solutions are compared. CAE solutions are matched to real values. CAE results
are verified or refuted. There are many differences between the options in
the solvers, there are steady states and transient-run
possibilities, etc. Software tools like Nastran, etc. need many coefficients
to solve the problem. This procedure is able to identify specific conditions,
fits the solver to the specific sample and performs CAE simulations to get
real, verified results. For example, passive radiators heated by an induction
heater are used for real tests. Temperature fields are measured by thermal
camera and structural deformations by measuring displacement. These values
are used in simulations and solved by finite elements method. Simulations are
performed in Siemens NX10 software, supported by solvers Nastran, MAYA, and
NX Multiphysics. Results are compared and matched in the simulation to
acquire a more precise solution in the following steps All these steps are
processed to get characteristics of thermal transfer simulation which will be
useful in difficult examples of simulation machines, machine tools etc. Key words:
heat load, thermal flow
simulation, finite element method, convection, conduction. Manufacturing
systems and passive safety Stanislav ŠPIRK1 1) Title (Ing., Ph.D.),
researcher, Regional Technological Institute, Faculty of Mechanical
Engineering - University of West Bohemia, Pilsen, Czech Republic Abstract: The main point of this paper is simulation focused on
passive safety of manufacturing systems. The passive safety of manufacturing
system is connected with smaller safety risk compared with another fields of
industry (e.g. automotive passive safety, rail vehicles passive safety or
terminal ballistics protection). The revolutions of manufacturing system
could reach 10000 [rpm]. The tangential speed on the larger diameter of a
manufacturing tool can be sometimes higher than a speed of rifle bullet. The
safety risk during an accident is significant. The parts could exceed the
safety barrier and they can cause fatal injury to the staff. The simulations,
presented in this paper, are aimed to the problem of terminal ballistic where
the experiment is complicated. The paper summarizes the findings from the
field of injuries caused by machine tools. Statistics of injuries are
described here as a possible starting point for determining the frequency of
occurrence. As an interesting point of research is described evaluation of
the safety risk caused by released machine parts. The two possible ways for
numerical simulations are shown in this paper. The first approach is the FE
(finite elements) simulation. The second approach is SPH (smooth particle
hydrodynamics) methodology. The advantages, disadvantages and applications of
these methods are described at the end of the paper. The conclusions could
represent the first step in simulations for safer structural design of
machines. Key words: manufacturing, passive
safety, explicit analysis, FEM, SPH. Imitation learning by following
the virtual paths for physical robots Aurel FRATU1,*
Mariana FRATU2 1) Prof., PhD, Dept.
of Automatics and Technology of Information, “Transilvania” University of
Brasov, Brasov, Romania 2) Assoc., Prof.
PhD, Dept. of Installations,
“Transilvania” University of Brasov, Brasov, Romania Abstract: This paper addresses the problem of imitation learning for
physical robots. Getting inspiration from the way humans learn new
skills by imitation, we adopt virtual robot
prototype as behavior identification guide for physical robot. Virtual
prototyping technique provides a virtual robot
homonym. Virtual robot prototype’ experience will greatly improve thanks to
an always-changing scenario. Combined
with a dataset transferring algorithm, we obtain an imitation learning
strategy with good performance under the physical constraints. The online
dataset transferring, of the mini-segments of virtual trajectories, make
opportune the guidance of the physical robot.
The virtual trajectories must be able to make early predictions of the physical robot's intentions. Developing a new training policy is the scope
of this study. We believe that this new approach outperforms previous
approaches on challenging imitation learning problems. Key words: virtual prototyping,
virtual trajectory, segmentation of motion data, learning by imitation,
guidance by imitation, training policy. Maturity
model for evaluation of resource efficiency in manufacturing SMEs Steffen BUTZER1,*,
Sebastian SCHÖTZ2, Katharina HAUCK3, Rolf STEINHILPER4 1) M.Sc., Chair
Manufacturing and Remanufacturing Technology, University of Bayreuth,
Bayreuth, Germany 2) Dipl.-Ing. (FH),
Fraunhofer Project Group Process Innovation, Fraunhofer IPA, Bayreuth,
Germany 3) B.Sc., Chair
Manufacturing and Remanufacturing Technology, University of Bayreuth,
Bayreuth, Germany 4) Prof. Dr.-Ing.,
Chair Manufacturing and Remanufacturing Technology, University of Bayreuth,
Bayreuth, Germany Abstract: Increasing global competition constraints have
changed the corporate landscape in the last few years. The aim of producing
goods with fewer resources not only leads to ecological advantages but also
leads to economic advantages. To face this trend, a lot of companies in the
manufacturing industry are anxious to increase performance and to use
resources efficiently. The objective of this paper is to provide a model and
a software tool which enable self-assessment of manufacturing SMEs (small and
medium-sized enterprises) regarding resource efficiency with relatively low
effort. The development of the maturity model is made based on the EFQM
(European Foundation for Quality Management) Model as an established basis
model and approved development framework. Besides the construction of the
model architecture, also the criteria which represent resource efficiency are
defined. At the end of the paper, the tool’s usability and practicability are
validated by implementing it in a manufacturing SME. Key words: Maturity Model, Resource
Efficiency, Process Improvement, Manufacturing, Small and medium-sized
enterprises. The diagnosis of financial balance in small
and middle size enterprises (SME) in times of economic crisis Nicolae BOIAN Assoc. Prof., PhD,
Department of Engineering and Management in Food and Tourism, University
“Transilvania”, Brasov, Romania Abstract: Small
and medium-size enterprises have a high vulnerability to changes in the
environment they operate that increase in times of economic crisis.
Determined by the onset of symptoms of depreciation, diagnosis analysis should
focus on issuing messages with clarity, brevity, opportunity and relevancy.
This will enable managers to apply operative corrective plans with high
chances of success. Because the first symptoms of depreciation occur in the
financial balance, we propose a diagnosis method based on five financial
equilibrium criteria. This method mainly aims to increase the objectivity of
conclusions. It allows the enterprise to assess the situation through a
financial balance score DEF, establishing the strategic corridor with the
greatest chance of success and so increasing the rate of success of
corrective plans and reducing the risk of the return imbalance. The paper
includes a case study to illustrate how to apply the method to a company. Key words: economic crises, financial balance, diagnosis, scoring note,
patrimony. Low-temperature
sterilization influence on fused deposition modelling
parts Diana POPESCU1,*, Daniel
VLĂSCEANU2, Lucian CURSARU3, Florin BACIU4,
Anton HADAR5, 6 1) Assoc. Prof., PhD,
Department of Machine and Production System, University POLITEHNICA of
Bucharest, Bucharest, Romania 2) Lecturer, PhD,
Department of Strength Materials, University POLITEHNICA of Bucharest,
Romania 3) Master student, University Politehnica of
Bucharest, Eng., Top Metrology SA 4) Lecturer, PhD,
Department of Strength Materials, University POLITEHNICA of Bucharest,
Romania 5) Prof., PhD,
Department of Strength Materials, University POLITEHNICA of Bucharest,
Romania 6) Romanian Academy
of Science Abstract: Fused Deposition Modeling (FDM) along with other
Additive Manufacturing (AM) processes are used today in a large number of
applications among which those dedicated to the medical field are focused on
manufacturing anatomical models, surgical devices, implants or prostheses.
While anatomical models are mainly manufactured for patient communication,
visualization, surgery training, rehearsal or simulation, there are also 3D
printed medical objects that come in contact with the patient body tissues
and fluids. Therefore, in their case sterilization and biocompatibility
testing are mandatory steps before use. In this context, the current paper is
studying the influence of sterilization on the compressive strength of FDM
objects, as well as on their dimensional accuracy. Standard samples for
evaluating the compressive strength of FDM objects manufactured from ABS
(Acrylonitrile-butadiene-styrene) material were used. For assessing the
dimensional accuracy, a test part was designed, manufactured and sterilized.
The test part was measured before and after sterilization, a comparison with
the virtual part being made. The results of this study can be used by
designers as they provide valuable information on how to design 3D printed
parts. Key words: Fused Deposition
Modeling, medical applications, sterilization, compressive strength,
dimensional accuracy. Identifying
possible solutions for a polyfunctional minimachine tool by means of ideas
diagram method Laurențiu
SLĂTINEANU1, Oana DODUN2,*, Margareta
COTEAŢĂ3, Gheorghe NAGÎŢ4, Marius
Ionuţ RÎPANU5, Irina BEŞLIU6 1, 2, 4) Professor, PhD, Department of Machine Manufacturing
Technology, “Gheorghe Asachi” Technical University of Iaşi, Romania 3, 5) Lecturer, PhD, Department of Machine
Manufacturing Technology, “Gheorghe Asachi” Technical University of
Iaşi, Romania 6) Lecturer, PhD,
Department of Mechanics and Technologies, “Ştefan cel Mare” University
of Suceava, Romania Abstract: There are situations when the problem of using
various machining processes is formulated and there is not a mechanical
workshop in which the necessary machine tools exist. In such a case, a
polyfunctional minimachine tool could be appreciated as useful, in order to
achieve many distinct machining processes. An analysis of the existing
solutions for polyfunctional machine tools and of the researches developed
about various constructive solutions of polyfunctional machine tools,
respectively, was achieved. The ideas diagram method is one of the methods
susceptible to be applied in order to facilitate an increase of the use of
the technical creativity. In order to
identify improved versions of a polyfunctional minimachine tool, the
principles specific to the ideas diagram method were discussed and applied.
Thus, some constructive aspects concerning a polyfunctional minimachine tool
were defined. If the ideas diagram method facilitates identifying of various
versions of the desired solution, it must be applied in association with
adequate methods of highlighting all the possible solutions, methods for
diminishing the number of solutions to be analyzed in detail and a method
able to carry out the most convenient solution. Such considerations were
applied in order to find possible solutions for a polyfunctional minimachine
tool. Key words: polyfunctional minimachine
tool, ideas diagram method, frame, machining units, solution selection. Comparison between
conventional milling and climb milling in robotic deburring of plastic parts Andrei Mario IVAN1,*, Cezara Georgia COMAN2,
Adrian Florin NICOLESCU3 1) PhD lect. eng., Machines and Production Systems Department,
Politehnica University of Bucharest, Romania 2) PhD lect. eng., Machines and Production Systems Department,
Politehnica University of Bucharest, Romania 3) PhD prof. eng., Machines and Production Systems Department,
Politehnica University of Bucharest, Romania Abstract: This
article presents the work performed by the authors in the field of the
robotic deburring. The scope of the research is limited to applications in
which an articulated arm, low payload robot manipulates the milling type
deburring tool around a plastic workpiece, which is clamped on a fixture. The
main objective of the research was to conduct some experimental procedures in
order to develop a comparative analysis between conventional milling and
climb milling approaches in robotic deburring. The experimental equipment
consisted of an articulated arm, 6 DOF Kawasaki FS10E industrial robot, with 10 kg payload. The robot was equipped with an
ATI RC-340 radially compliant deburring tool. The experimental procedure was
conducted by creating two deburring programs around the outer edges of the
workpiece (one program corresponding to the conventional milling approach and
the other program corresponding to the climb milling approach). The programs
were developed using the point-to-point block teaching method on the
teach-pendant. Each program was then run several times, with gradually
increased radial contact force of the tool (by increasing the compliance
pressure) and the results after each program run were observed by visual
inspection. Based on these observations, the conclusions were drawn regarding
the efficiency and applicability of each feed direction approach. Key words: robotic deburring, climb milling, conventional milling, radial
compliance, radial contact force. Electronic mail: orgcom@icmas.eu |
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