The modular robotic systems

jadesoreAI and Robotics

Nov 13, 2013 (3 years and 11 months ago)

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The modular robotic systems

O
.
Tătar
*
,1
,
S. Stan
**
,2
,
and

D
.
Mandru
***
,
3

1
,2,3
Department of Mechanisms, Precision Mechanics and Mechatronics,

Faculty of Mechanics, Technical University of
Cluj
-
Napoca,

B
-
dul Muncii, nr. 103
-
105, 400641, Cluj
-
Napoca, Romani
a

A very important design goal of these robotic systems is the adaptability to the inner diameters of the pipes. In this paper,

we
proposed two wheeled
-
type in
-
pipe modular robotic systems. Thus, the studied modular robotic systems are characterized by
an
adaptable structure, based on linkages mechanisms.
The prototypes were designed in order to inspect pipes with variable

diameters within 140 and 200 mm.


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1

Introduction

These modular systems prezented in the

paper are composed of driving modules (which are using mechanisms with
articulated links) and passive modules.

The first module (driving module) generates the traction force. The passive module is
necessary to carry the control electronic equipment and fo
r the transport of the needed equipment for realization of the in
-
pipe inspection.

Pipe diameter, which is one of the important size parameters, limits the working space occupied by the
inspection robot. Therefore, it is necessary to be considered that a m
odular robotic system is designed for a certain size of
pipe diameter.

2

The developed in
-
pipe modular robotic system

2.1

The f
irst prototyp
e

The driving module contains the three mechanisms, symmetrically disposed along the longitudinal axis of the rob
ot. The
force that the driving module mechanism exercises on the pipe walls is generated with the help of an extensible spring. The
helical spring disposed on the central axis assures the repositioning of the structure, in the case of the pipe diameters’
v
ariation.

The components of the driving module are

(Fig. 1 a)
:

1



helical spring,
2



translational element,
3



worm wheel,

4



worm gear,
5



worm, actuator support,
6



actuator,
7



actuator support,
8



link,
9



central axis, 10


wheel

[1], [2]
.



a)
b)


c)


Fig. 1

a) The components of the driving module

b) The structural scheme for modular robotic system


c
)

The photo of the first in
-
pipe modular robotic system
.

____________________

*

Corresponding author:

e
-
mail:

olimpiut@yahoo.com
, Olimpiu.Tatar@

mmfm.utcluj.ro
,

Phone:

+40 264 40
1 681
, Fax: +40264
-
415490

**

e
-
mail:
sergiustan@ieee.org
,
Phone: +40 264 401 755, Fax: +40264
-
415490
,

***

e
-
mail:

Dan.Mandru@

mmfm.utcluj.ro
,
Phone: +40 264 401 645, Fax: +40264
-
415490

Section 00

2


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The weight of the driving module (the weight of

current feeding wires is also considered) is 978 g and the weight of the
passive module
is 1070 g. The wheels have the radius

r = 25 mm and the length 17 mm and

the component elements of the
driving module have the lengths are (Fig. 1b): h
1
=30 mm; h
2

= 70

mm, h
3

= 135 mm.

The actuation of the driver wheels is
made through three worm gears with z
1

= 1
(one thread)
, z
2

= 52
teeth
. These robot system
s

have movement capacities for
inspection in (140


200) mm diameter pipes in horizontal or vertical configurat
ion (Fig. 1c).

2.2


The s
econd

prototyp
e

The second modular robotic
system

will contain two motor modules and a passive module. In figure 2 a., a structure of a
driving module is presented, composed of 6 slider
-
crank mechanisms. These are placed each two

in three
plans at 120˚
around the central axis. Each driving modules has a weight of 630 g. The wheels have a radius r = 25 mm, a length of 17 mm
and the component elements have the lengths: h
1
= 95 mm, h
2
= 58 mm, h
3
= 53 mm. The actuation of the driver wheels is
mad
e through three worm gears with z
1

= 1 (one thread), z
2

=42, z
3

=38, z
4
=38 teeth. The passive module have a weight of
700 g, the wheels have the radius r = 17 mm,

a

length of 7 mm and they are equipped with tires.

The passive module has 6
wheels that slide

perpendicular to the ax
is of module disposed at 120˚ around the central axis.

The second modular robotic
system, that has the 3D model presented in figure
2b
, is in developing stage. This robotic system has movement capacities
for inspection in (140


180) mm diameter pipes.






E
2
ME
E
1
D
1
F
1
C
1
F
2
C
2
G
2
B
2
B
1
O
1
A
1
O
1
O
O
2
D
2
R
h
1
h
2
h
2
h
3

a)

b)

c)




Fig.
2

a) The structure of a driving module b)

The 3 D model of modular robotic system



c)
The photo of the second

in
-
pipe modular robotic system (
in developing stage)

3

Conclu
sion


In this paper, we proposed two wheel type in
-
pipe robotic systems, defined
by adaptable structure
s
, based on different
mechanisms.
A very important design goal of the mobile in
-
pipe robotic systems is the adaptability to the inner diameters of
the pi
pes
.



The first prototype was designed in order to inspect pipes with variable diameters between 140 and 200 mm, and second
prototype has movement capacities for inspection of 140
-

180 mm pipe diameters
.
The force which the mechanism from the
driving mod
ule exercises on the pipe walls is generated with the help of several extensible resorts
.
The driver wheel is
actuated by a D.C. motor through gear wheel transmission
.
In the second part, another one structures based on slider
-
crank
mechanisms are proposed
; for this, the experimental prototypes are under development.

Acknowledgements

This work is supported by PNII
-

IDEI Project, ID 1056:
Mode
l
ling, simulation and development of robotic system
families used for inspection and exploration


References


[1
]

O
. Tătar, D. M
â
ndru, and V., Roş, Agricultural pipe networks maintenance using robotic systems Proceedings of the 35
th

International Symposium Actual Tasks On Agricultural Engineering, Opatija, Croatia, , p.187
-
197, (2007).


[2]

O. Tătar, D. Mândru,
and
I.
Ardelean, Development of mobile minirobots for in pipe inspection tasks,
Mechanika, Nr. 6(68), p. 60
-
64,
(2007).