Designing the virtual model of a mechatronic micro positioning and micro-measuring system for experimental model realization

IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 08 | Aug-2013, Available @ http://www.ijret.org 239
DESIGNING THE VIRTUAL MODEL OF A MECHATRONIC MICRO-
POSITIONING AND MICRO-MEASURING SYSTEM FOR
EXPERIMENTAL MODEL REALIZATION
Simona Istrițeanu1
, Gheorghe I. Gheorghe2
1
”Valahia” University, Romania, simona,.istriteanu@yahoo.com
2
General Manager– INCD Mechatronics & Measurement Technique, Bucharest, Associated Prof. in U. Valahia of
Târgovişte, U.T.M Bucharest and U. P. Bucharest, Scientific Doctorates Coordinator in Doctoral School of Mechanical
Engineering, U. V. of Târgovişte, Corresponding Member of the Academy of Technical Sciences in Romania,
geocefin@yahoo.com
Abstract
This paper aims is to present the realization of a virtual model, as well as the experimental model for a mechatronic micro-positioning
and micro-measuring system on two axes, OX, and OZ respectively. The paper also includes experimental results on measuring the
gripping force developed between the fingers of an electrical micro-gripper, with two fingers, incorporated into the experimental
model of a mechatronic micro-positioning system.
Index Terms: flexible mechatronic system, micro-positioning, micro-gripper
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1. INTRODUCTION
Current micro-positioning equipment development is directly
influenced by the evolution of measurement technologies,
manufacturing technologies of components made of
semiconductor materials, as well as electro-mechanical micro-
systems fabrication technologies (MEMS). Series production
of micro-positioning systems requires high demands on
mechanical design, choice of materials, manufacturing and
testing methods [1]. These high demands have direct influence
on costs.
In positioning application development, it is not enough
simply to optimize individual components within a usual
micro-positioning system, but innovative design principles
must be relied on [2].
Micro-positioning systems are powered by electric motors
platform with travel routes from a few millimetres to hundreds
of millimetres. As guidance systems commonly use roller
bearings, generating frictional forces, their resolution and
reproducibility is generally limited to 0.1 μm (usually not
lower than 0.1 μm) [3].
For mechatronic applications it which it is necessary to obtain
sub-micrometer resolutions, it is required to use frictionless
positioning systems, such as linear electromagnetic motors,
electro-dynamic actuators or piezo-electric actuators. In such
applications, electro-dynamic motors and linear electro-
magnetic actuators are less used because they generate a lot of
heat and produce magnetic fields that can interfere with other
processes [4].
Increasing the competitiveness and efficiency of
manufacturing impose to current technological equipment
configurations to meet increasingly stringent requirements on
performance accuracies that are geared towards the micro- and
nano-metric range, as well as increased automation.
In this regard, the National Institute for Research and
Development in Mechatronics and Measurement Technique
Bucharest has conceived, designed and developed a flexible
mechatronic micro-positioning system with two axes that meet
the requirements outlined above.
2. REALIZATION OF THE VIRTUAL MODEL OF
A MECHATRONIC MICRO-POSITIONING AND
MICRO-MEASURING SYSTEM
In order to realize the virtual model of the flexible micro-
positioning mechatronic system, there has been established the
technical theme of the work, with technical characteristics, the
scheme of the experimental model of the mechatronic system
(figure 1), and operation cyclorama (Table 1).
Thus, the technical features are: positioning accuracy: ±
0.00025 mm; sleds cycle: 0 ÷ 200 mm on x and on z, load
transport on axis x: 100 ÷ 200 N, load transport on axis z is 25
÷ 50 N , (electric or pneumatic) gripper, with the possibility of

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gripping and positioning parts up to 0.5 kg; power supply: 220
Vca/50 Hz (15V-CC motors, 24V-griper and controller); work
mass: 1250x780x750 (mm).
Figure 1 schematically depicts the experimental model of the
micro-mechatronic system, highlighting its components.
Fig. 1: Scheme of the experimental model of the mechatronic
system
Mechatronic system components:
1 & 10 –CC motors
2 & 8 – linear axes
3 & 9 – linear axes sleds
4 – Electric gripper
5 – Profiled fingers
6 – Piece
7 – Temperature sensor
11 & 11’– power
12 & 12’– controllers
13 – Piece presence sensor.
Overview of the mechatronic micro-positioning
system:
The mechatronic micro-positioning system mainly features the
positioning system made of two linear axes that are
electrically driven. The two axes of the designed micro-
positioning system are connected to two controllers, the linear
cycle for each positioning axis being 200 mm.
The electric gripper is mounted on the vertical sled, ensuring
the grabbing of the piece in order to ensure micro-positioning.
The gripper fingers will be costumed depending on the shape
of the marks to be positioned.
Since positioning accuracy is of sub-micron size, specific
environmental conditions are required and thus a temperature
sensor is mounted in the structure of the system.
The temperature sensor is included in the control circuit, in
order to warn or turn the system off when exceeding the
ambient temperature which may compromise the accuracy.
Linear axis driving is ensured by CC motors and transmission
type screw-nut type ensures safety and positioning accuracy.
In Table 1 is shown the operating cyclorama of the micro-
positioning system.
Table1. Operating cyclorama of the micro-positioning system
No.
crt.
Functioning cycle phases Parameters
1 Connecting to network
Computer initiation
Axes powering, position sensor,
optical barrier
Software loading
2 System initiation– Displacement
in reference position 01
3 A – gripper dies opening
4 1 – horizontal displacement x=120 mm;
z=100mm
5 2 –vertical displacement
(descend)
x=120mm;
z=160mm
6 B – dies closing Piece grabbing
7 3 – vertical displacement
(ascend)
x=120mm;
z=58mm
8 4 – horizontal displacement x=190mm;
z=58mm
9 C– dies opening Piece deposition
10 5 – horizontal displacement
(recessing)
x=120mm;
z=58mm
11 6 – vertical displacement (retreat) x=120mm;
z=100mm
12 D – dies closing
13 Return to the reference position
01
x=100mm;
y=100mm
Also, for the realization of the virtual model, there has been
established the product designation, i.e. positioning precision
in measuring, characterizing surfaces in complex vector space,
intelligent mechatronic system for determining global
constants of measurements of optical systems with complex
software algorithms, system calibration of inductive
displacement sensors and penumo-electric sensors. The kinetic

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scheme of the experimental model of the mechatronic system
is depicted in fig. 2.
Fig. 2: Kinetic scheme of the experimental model of the
mechatronic system
The main part of the flexible micro-mechatronic positioning
system consists of the ensemble of the two electrical linear
axes.
The design of the two electric linear axes was performed
individually for each axis for horizontal or vertical mounting.
Figure 3 presents a linear axis, highlighting its components.
Fig. 3: Mechatronic ultra precise x/z axis
1- Ultra precise actuator for x/z axis; 2- Support for x/z axis
actuator; 3- Guiding Support for x/z axis;
4- Precision nut element; 5- Precision screw element; 6- Ultra
precise sensor; 7- Positioning support element
In figure 4 a) & b) are presented the assembly of the x-z axes,
vertically and respectively horizontally, by offering an
example of the driving of the forces and moments on the
mechatronic axis [xz].
Fig4. Representation of the vertical assembly a) and the
horizontal assembly b) for the mechatronic linear axis
The designed positioning system is made up of two linear axes
mounted vertically so that they will build the XZ Cartesian
system of the assembly.
In figure 5 is presented the virtual assembly of the linear
positioning axes and the gripping system mounted on the
linear axis Z, highlighting the linear axis X.
Fig.5: Assembly of the linear positioning axes, highlighting
component elements:1- mechatronic OZ axis; 2- mechatronic
OX axis; 3- micro- high-tech grabbing device; 4- linking
element
In figure 6 are presented the linear positioning axes, the
grabbing system, the piece repository and the optical barrier
mounted on the worktable of the mechatronic micro-
positioning system.
3
2
14
7
2 31 4 5
6

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Fig6 Virtual model: linear x-z axes, electric gripper and
optical barrier mounted on worktable made of aluminium
Fig7: Horizontal and vertical axes system, grabbing system
and temperature sensor, mounted on the worktable
In figure 8 is presented the virtual model of the electric
gripper, on which are placed dies and grabbing fingers of
cylindrical pieces.
Fig8: Virtual model of the electric gripper, on which are
placed dies and grabbing fingers of cylindrical pieces.
In figure 9 is presented the detail: virtual grabbing system, in
open position.
Fig. 9: Detail - virtual grabbing system, in open position
In Figure 10 is depicted the whole virtual model of the
mechatronic system.
Fig. 10 Virtual model of the mechatronic micro-positioning
system
The virtual model of the mechatronic system for micro
positioning resulted in the realization of the experimental
model.
3. REALIZATION OF THE EXPERIMENTAL
MODEL OF THE MECHATRONIC SYSTEM FOR
MICRO-POSITIONING
3.1. Overview of the mechatronic system for micro-
positioning
The experimental model of the mechatronic system for micro-
positioning was conceived, designed and built in modular
fashion and is placed in the laboratory of INCDMTM
Bucharest. The experimental model was based on activities
such as: studies and assumptions on components and systems
for the integration of micro-components: guidance systems,
micro-actuators, micro-sensors, micro-transducers, micro-
controllers and computer units, high performance and
programmable functions that ensure operational self-
regulation and intercommunication, conceptual models and
design assumptions and micro-mecatronics mechatronic
systems, examples of constructions used in the structure of
technological / micro-technological and control and
measurements; the design of the mechatronic system for ultra-
precise positioning; the realization of the virtual model of the
mechatronic micro-positioning system.
The experimental model of the mechatronic micro-positioning
system for positioning and micro-positioning was designed to
be integrated in the following applications: precision
positioning in measuring, characterizing surfaces in complex
vector space and temperature, determining global constants of
measurements of optical systems with complex software
algorithms, inductive displacement sensor and pneumo-
electric sensor calibration.
The mechatronics system for micro-measurement and micro-
positioning consists of the following subsystems: linear

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positioning vertical axis; gripper with two fingers; controller;
beam sensor; temperature sensor; positioning sensor; process
software; electric actuator subsystem; process software;
support mass.
The main part of the mechatronic system is the micro-
positioning system, consisting of two linear axes, electrically
powered. The two linear axis of micro-positioning system are
connected to the two controllers C-863.10 model; the linear
stroke for each positioning axis is 200 mm.
Linear axis drive is provided by CC motors, and the
transmission screw-nut type ensures safety and positioning
accuracy. The linear electric axis transforms movement of
rotation of CC motor 24 V, in the translational movement by
screw-nut type mechanism, the displacement increment is 0,2
µm.
In figure 11 is shown a linear axis, highlighting its
components.
Fig. 11: Linear electric axis
The component elements of linear axis are:
1 CC motor
2 Screw drive
3 Platform of mechatronics axis – z/x
4 Positioning sensor
5 Connection cable to controller
In general, the linear axis of sub-micronic precision have
linear racing limited to avoid aggregation of errors.
The system flexibility lies in the possibility of mounting two
electric axes both horizontally and in the vertical plane; the
displacement errors are corrected by the specific software.
3.2. Assembly of electric linear axes
By design, the mechatronic axes are designed for one single
positioning direction, horizontally or vertically mounted.
In order to achieve the accuracy guiding specified and to avoid
guides torsion, axes must be mounted on a flat surface.
The assembly of linear electric axes has been achieved by
positioning each other so as to materialize the two axes of
movement in a vertical, x-z (figure no. 12).
Fig. 12: Mounting and assembly of two linear mechatronic
axes in horrizontally plane
The linear axis x is fixed with screws and nuts in channels
“T“of the work table, as can be seen in the figure 13.
Fig.13: Mounting and assembly of mechatronics linear axes in
vertical plane
Fixing the horizontal axis, with screws and nuts in channels
“T“ of the work table.
In order to achieve the positioning system, the two linear axes
are mounted in the vertical plane forming a Cartesian system
XZ. The linear axis Z was set on the table of the X axis, in
vertical position, through the screws (figure 14).
Fig.14: Assembly linear axes in vertical plane
Fixing the horizontal axis, with screws and nuts in channels
“T“ of the work table.
In order to achieve the positioning system, the two linear axes
are mounted in the vertical plane forming a Cartesian system
XZ. The linear axis Z was set on the table of the X axis, in
vertical position, through the screws (figure 15).

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Fig. 15 The two linear axes, mounted in the vertical plane
Electric linear axes are precisely machined, with high
precision guides, embedded in passive aluminium alloy
support, having high stability with a minimal weight, allowing
movement of 25 ÷ 200 mm.
Linear guides with re-circulating ball bearings, ensures high
rigidity of the system; the platforms of linear axes can carry up
to 20 kg and push / pull up to 50 N.
To protect the equipments, on the sled are mounted non
contact sensors with Hall Effect, sensors that provide highly
accurate automation opportunities.
The proper functioning of the linear axis is only possible in
combination with a controller and appropriate software. The
two linear axes of micro-positioning system are connected to
two controllers (figure 16) C-863.10 model; the linear stroke
for each positioning axis is 200 mm.
Fig. 16: Controllers of the two electric linear axes
The control was selected so as to be able to read and process
the reference signals and limit sensors and incremental
position encoding to ensure proper performance of the servo -
control system.
For the safety of electric linear motion sleds are used groups
of Hall effect sensor, which informs about the position of an
object relative to a reference point.
Since positioning accuracy is of sub-micron size, we use a
temperature sensor mounted near the system. Temperature
sensor (Figure 17) is included in the control circuit, in order to
warn or stop the system when ambient temperature exceeded
that may compromise accuracy. Sensor, with no moving parts,
greatly increases reliability compared to other types of
electromechanical sensors and in addition can be adequately
protected.
Fig. 17 The system’s components, mounted on the worktable
The electric gripper LEHZ 32K2-22 was assembled on the
table of vertical axis through connecting pieces (figure no.18).
Fig.18: LEHZ 32K2-22 Gripper, connected with a controller,
ensure automatic loading –unloading of the parts
The electric grippers are mounted on the vertical sledge of
micro-positioning system. It provides for catching the piece
for micro-positioning, enabling support of a part with a mass

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up to 0,5 kg. The gripper fingers will be individualized by
shape of the parts that will be positioned.
In figure 19, are represented comparatively, the virtual model
and the experimental model of micro-positioning mechatronic
system.
Fig. 19: Virtual model and experimental model of micro-
positioning mechatronic system.
The innovative character of this mechatronic product is
achieved by modularity and flexibility, is intended as for
applied research and for technological applications.
4. MEASUREMENT OF VALUES FOR
CLAMPING FORCE
The clamping forces developed by the fingers of electric
micro-gripper, included in the gripping system of micro-
positioning mechatronic system, were measured in static
conditions, using a compact force transducer [5].
The compact force transducer, can measure static and dynamic
compression forces up to 50kN. This force transducer is
suitable for micromanipulation, pharmaceutical applications,
press connection processes, etc.
This force transducer, was chosen to determine the values of
the clamping force, because the material from which it is made
(stainless steel) and the compact and robust design provide a
high stability, in particular in a micro-measurement field,
enabling reliable measurements.
The tests consisted of measuring the clamping force developed
by the fingers of micro-gripper at the catching of part.
The part of handling is considered to be the force transducer,
together with gauges used to vary the size of the piece.
In the closed position, between electric gripper jaws remain a
distance of 29,5 mm. Maximum opening of the jaws of electric
gripper is 49,25 mm. The force transducer used for the
experiments has a height of 27,9 mm. In order to vary the size
of parts to be handled, to achieve measurements, were used
gauges ranging in size between 2 ÷ 6,6 mm.
For each value of thickness of the workpiece, were made three
measurements of the clamping force. In table 2 are
summarized the average values obtained for the clamping
force, depending on the size of the workpiece.
Table 2 – The average values obtained for the clamping force,
depending on the size of the workpiece.
No.
crt. Workpiece thickness
[mm]
Average value for clamping
force
[N]
1 29,9 52,43333
2 30,0 51,94667
3 30,1 49,92333
4 30,9 51,30333
5 31,4 52,41667
6 31,9 41,50333
7 32,4 43,46667
8 33,9 47,08333
9 34,1 44,70000
In figure 21 are shown the trend of change the average
clamping force depending on the dimensions of the workpiece.
Fig. 21: The trend of change the average clamping force
depending on the dimensions of the workpiece.
Although the first three tests seemed that the clamping force
will decrease uniform, as you increase the size of the piece, at
the end of nine tests it was found that the variation can not be
considered uniform of the clamping force.
The linear evolution of a clamping force depending on the size
of the part is shown in figure 22.

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Fig. 22: The linear evolution of a clamping force depending
on the size of the part
From the graph shows that the trend of clamping force is to
decrease, as you increase the size of the workpiece, but this
trend can not be considered an uniform decrease.
CONCLUSIONS
It was shown the realisation mode of virtual model and
experimental model of a micro-positioning mechatronic
system. Consisting of two linear axes electrically driven, with
linear maximum stroke of 200 mm the system is a flexible
mechatronic product, multifunctional, integrated in
technological platforms.
The innovative character of this mechatronic product is
achieved by modularity and flexibility, is intended as for
applied research and for technological applications. Specific
applications that can be integrated micro-positioning
mechatronic system are: precise positioning of a various
components, to measure and micro-processing;
characterization of surfaces in complex vector space and
temperature; integration in intelligent mechatronic systems to
determine global measurements constants of optical systems
with complex software algorithms; calibration system of
inductive sensors for displacements and air powered sensors.
The micro-gripper used in the gripping system as electrically
powered, realised in compact design, having reduced
dimensions, but allowing relatively large variations of the
stroke, obtaining at the same time values of the clamping force
equivalent to air gripper widely used.
Although the first three tests seemed that the clamping force
will uniform decrease, as you increase the size of the part, at
the end of nine tests it was foundthat the variation of a
clamping force can not be considered uniform. The clamping
force Forța de strângere have average values in the range
41.50333 ÷ 52.43333 N, which is a difference of 10.93 N, for
dimensions of a workpiece within the range 29.9 ÷ 34.1 mm
(that is a variation of 4.2 mm).
ACKNOWLEDGEMENTS
This work was partially supported by the Operational
Programme for Human Resources Development 2007-2013.
Priority Axis 1 "Education and training in support of
economical growth and social development based on
knowledge". Major area of intervention 1.5. "Doctoral and
postdoctoral programs in support of research". Project title:
"Doctoral preparing of excellence for the knowledge society
PREDEX". POSDRU/CPP 107/DMI1.5/s/77497.
REFERENCES
[1]. Bolton, W. MECHATRONICS, a multidisciplinary
approach. Electronic control systems in mechanical and
electrical engineering, 4th Edition. s.l. : Pearson, Prentice Hall,
2008
[2]. Micropositioning or Nanopositioning. [Online] [Cited:
august 11, 2013.]
http://www.physikinstrumente.com/en/products/prdetail.php?s
ortnr=700400.
[3]. Gheorghe, Gheorghe. Intelligent MicroNanoRobotics
Bucharest: CEFIN, 2010. ISBN 978-606-92267-5-9.
[4]. Gheorghe, Gheorghe and Bădiță, Liliana. Advanced Micro
and Nano Technologies in Mechatronics. Bucureşti : CEFIN ,
2009. 978-606-92267-1-1.
[5]. HBM Transducers & Sensors [Online] [Cited: dec. 11,
2013.] http://www.hbm.com/
BIOGRAPHIES
Simona ISTRIŢEANU, From 2010 to
present: PhD stundent, 3rd year of study in
the Doctoral School in University ”Valahia“
of Targoviste, Field: Mechanical
Engineering; 2008-2011- Graduate of the
Academy of Economical Studies in
Bucharest, Faculty of Economic
Management; 1990 – 1995: University “Politehnica
Bucuresti”, Facultaty of Engineering and Technological
Systems Management, Bachelor’s Degree in Industrial Robots
Specialization.
Relevant professional experience: 2005 ÷ currently, Head of
the Internal Audit Department - INCDMTM, 2004 ÷ present:
Researcher at the National Institute of Research in Precision
Mechanics, 1995-2004: Engineer in SC AUTOMATICA S.A.
Bucharest - Manipulators and Industrial Robots Design
Department
Prof. PhD Eng EurEng GHEORGHE I.
GHEORGHE, Graduate (1970) Faculty of
TCM, Department of Mechanics, Graduate
(1992-1993, 1993, 1994, 1995, 1978,
1998, 2006) of graduate courses of
Manufacturing Marketing, Planning,
Financing, Investment Costs and

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Calculation, Management and Organization, Project
Management, Leadership, Creativity, Quality Management,
Auditing, International Economic Relations in Germany,
Austria and Romania, Doctor in Technical Sciences
(Mechanics, Mechatronics and Robotics), (1978), UP
Timisoara - Romania, Associate Professor (1971-2013) in the
University “Politehnica” of Bucharest - Romania, (2000-2013)
University “Valahia” of Targoviste - Romania and (2007-
2013) Titu Maiorescu University - Bucharest, Romania,
General Manager of INCD-Mechatronics and Measurement
Technique - Bucharest, Romania; scientific doctorates
coordinator (2010-2013) in Doctoral School - Mechanical
Engineering in University “Valahia” - Targoviste Romania,
Author (main author or in collaboration with others) of more
than 44 scientific and academic books and over 400 national
and international scientific papers [including ISI (35)].

Designing the virtual model of a mechatronic micro positioning and micro-measuring system for experimental model realization

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