RECONFIGURABLE MANUFACTURING SYSTEMS

jadesoreAI and Robotics

Nov 13, 2013 (3 years and 4 months ago)

46 views

RECONFIGURABLE MANUFACTURING SYSTEMS


Autor:

Anca Dana SÎRCA
, University of Oradea

Coordinator: Radu Cătălin ȚARCĂ


Key words: Reconfigurable Manufacturing System (RMS)
,

FMS
, Reconfigurable robots.


Abstract:
A Reconfigurable Manufacturing System (RMS) com
bines Dedicated Manufacturing

Lines (DML) with
Flexible Manufacturing Systems convertibility. Thus, it has the

capacity of producing a wide range of parts, at different
production levels and in conditions of high economic efficiency. The combination of hig
h performance communication
means
-

existing or to come
-

plus high level and standardized modelling of industrial equipment must bring more
efficiency in design and operation of computer controlled manufacturing.


1.

HISTORY AND DEVELOPMENT


In its earliest
form, manufacturing was usually carried out by a single skilled
artisan

with
assistants. Training was by
apprenticeship
. In much of the pre
-
industrial world the
guild

system
protected the privileges and trade secrets of urban artisans.

Before the
Industrial Revolution
, most
manufacturing occurred in rural areas, where household
-
based manufacturing ser
ved as a
supplemental subsistence strategy to

agriculture

(and continues to do so in places). Entrepreneurs
organized a number of

manufacturing households into a single enterprise through the
putting
-
out
system
.


2.

TYPES OF

MANUFACTUR
ING


Manufacturing

(from
Latin

manu factura
, "making by hand") is the use of tools and labor
to make things for use or sale. The term may refer to a vas
t range of human activity, from
handicraft

to
high tech
, but is most commonly applied to industrial production, in which
raw materials

are
tr
ansformed into
finished goods

on a large scale.


Traditional Manufacturing Systems as Dedicated cannot face new market requirements
because constitutive machine tools were designed to do a single operation.

Cellula
r manufacturing
is a fairly new application of group technology. Group
Technology is a management strategy with long term goals of staying in business, growing, and
making profits. Companies are under relentless pressure to reduce costs while meeting the h
igh
quality expectations of the customer to maintain a competitive advantage. Successfully
implementing Cellular manufacturing allows companies to achieve cost savings and quality
improvements, especially when combined with the other aspects of lean manufa
cturing. Cell
manufacturing systems are currently used to manufacture anything from hydraulic and engine
pumps used in aircraft to plastic packaging components made using injection molding.

Group Technology

or
GT

is a manufacturing philosophy in which the
parts having
similarities (Geometry and/or manufacturing process) are grouped together to achieve higher level
of integration between the design and manufacturing functions of a firm. The aim is to reduce work
-
in
-
progress and improve delivery performance b
y reducing lead times. GT is based on a general
principle that many problems are similar and by grouping similar problems, a single solution can be
found to a set of problems, thus saving time and effort. The group of similar parts is known as
part
family

and the group of machineries used to process an individual part family is known as
machine
cell
.

It is not necessary for each part of a part family to be processed by every machine of
corresponding machine cell. This type of manufacturing in which a part
family is produced by a
machine cell is known as
cellular manufacturing
.

A
Flexible Manufacturing System

(FMS) is a manufacturing system in which there is
some amount of flexibility that allows the system t
o react in the case of changes, whether predicted
or unpredicted.

Most FMS systems comprise of three main systems. The work machines which are often
automated CNC machines are connected by a material handling system to optimize parts flow and
the central c
ontrol computer which controls material movements and machine flow.

The main advantages of a FMS is its high flexibility in managing manufacturing resources
like time and effort in order to manufacture a new product. The best application of a FMS is found
in the production of small sets of products like those from a mass production.

The best application of a FMS is found in production of small sets of products
.


Advantages:

-

Productivity increment due to automation;

-

Preparation time for new products is s
horter due to flexibility;

-

Saved labor cost, due to automation;

-

Improved production quality, due to automation.


Disadvantage:

-

It is not always necessary that on increasing flexibility productivity also increases.


2.

RECONFIGURABLE MANUFACTURING SYS
TEMS


Definition:

A
Reconfigurable Manufacturing System

(
RMS
) is one designed at the outset for rapid
change in its structure, as well as its
hardware

and
software

components
, in order to quickly adjust
its production capacity and functionality within a part family in response to sudden market changes
or intrinsic system change.

The Reconfigurable Manufacturing System (RMS) as well as one of its components


the
Reconfigurable

Machine Tool (RMT) were invented in 1999 in the Engineering Research Center
for Reconfigurable Manufacturing Systems (ERC/RMS) at the University of Michigan College of
Engineering. The RMS goal is summarized by the statement


Exactly the capacity and
fun
ctionality needed, exactly when needed
.

Ideal Reconfigurable Manufacturing Systems possess six core RMS characteristics:
Modularity, Integrability, Customized flexibility, Scalability, Convertibility, and Diagnosability. A
typical RMS will have several of
these characteristics, though not necessarily all. When possessing
these characteristics, RMS increases the speed of responsiveness of manufacturing systems to
unpredicted events, such as sudden market demand changes or unexpected machine failures.. The
RM
S facilitates a quick production launch of new products, and allows for adjustment of production
quantities that might unexpectedly vary. The ideal reconfigurable system provides exactly the func
tionality and production capacity needed, and can be economi
cally adjusted exactly when needed.
These systems are designed and operated according to Koren’s RMS Principles.

The components of RMS are CNC machines, Reconfigurable Machine Tools.
Reconfigurable Inspection Machines and material transport systems (such
as gantries and
conveyors) that connect the machines to form the system. Different arrangements and
configurations of these machines will have an impact on the system productivity. A collection of
mathematical tools, which are defined as the
RMS Science Base
, may be utilized to maximize
system productivity with the smallest possible number of machines.


To be more specific in the figure under this text
is shown the evolution steps
:




a)







b)






c)


Figure 1. Evolution steps in case of a tool used in assembling operations

a


Dedicated ; b


Flexible; c


Reconfigurable.



Modular
self
-
reconfiguring
robotic
systems are
autonomous

kinematic machines with
variable morphology. Beyond conventional actuation, sensing and control typically found in fixed
-
morphology robots, self
-
reconfiguring robots are also able to deliberate
ly change their own shape
by rearranging the connectivity of their parts, in order to adapt to new circumstances, perform new
tasks, or recover from damage.

The modular building blocks usually consist of some primary structural actuated unit, and
potentia
lly additional specialized units such as grippers, feet, wheels, cameras, payload and energy
storage and generation.

Stochastic reconfiguration

relies on units moving around using statistical processes (like
Brownian motion). The exact location of each uni
t only known when it is connected to the main
structure, but it may take unknown paths to move between locations. Reconfiguration times can be
guaranteed only statistically. Stochastic architectures are more favorable at micro scales.

A current
system

is
M
-
TRAN
which

is a
hybrid

type
self
-
reconfigurable system. Each
module is two cube size (65mm side), and has 2 rotational DOF and 6 flat surfaces for connection.
It is the 3rd M
-
TRAN prototypes

as it is shown in the following figure
.


3.

RECONFIGURABLE ROBOTS



At University of Oradea it is possible to see and handle a reconfigurable robot which can be
modified in to 8 configurations. The robot is a Lego type and he can be configured in the following
models:

Simple robot; Basic robot; Lightseeker; Tracker; Robo
t with Obstacle Detection;
Walking robot (Figure 2.a); Lightseeker with Obstacle Detection (Figure 2.b); Robot with
Edge Detection.


The main structure a Lego type is that taking or adding few parts in its configuration the
robot is able to do a new task
. These parts may be sensors, wheels, bumpers, legs, etc. In this way
anything that can stop you to build your robot is imagination.


The main processor that is able to compile the task into acting is the microcontroller. He is
the brain of this robot and

can be connected to PC by a serial port cable.







a)








b)


Figure 2. Samples of reconfigurable robot made from Lego


a


walking robot; b


lightseeker with obstacle detection


Advantages:

-

it
can be modular;

-

easy to integrability;

-

customization;

-

convertibility obtained within reasonable cost to manufacturers;

-

rapid scalability to the desired volume;

-

diagnosability.


Disadvantage


-
because that reconfiguration is quite new, we couldn’t find disa
dvantages to it, but it is also
very hard to input some mistakes because of the various combination that can be done with
reconfigurable manufacturing systems (RMS)


4.

CONCLUSION:


1. Up to now, the reconfigurable

manufacturing systems is not yet a matured

a
rea; this is why the industry feedback is not

satisfactory.

2. Further research is necessary at the

machine level, where the technical and

economic consequences are very important, at

entire manufacturing level.

3.
The reconfiguration science will form the

basis

for a vital production technology in this
era of

global market competitiveness


that it will

involves into entirely new manufacturing field

with enduring benefits for the economy and

society.



5.

REFERENCES:


Goebel, P. (2004) Reconfigurable Manufact
uring Systems. Proceeds of the International
Conference on Competitive

Manufacturing, COMA’04, Stellenbosch, South Africa.

Koren, Y., and Kota, S. (1999) Reconfigurable Machine Tools.

Radu C. Țarcă, Sisteme de fabricatie flexibila, U. Oradea

Moon, YM and K
ota, S.: Design of reconfigurable machine tools. Journal of Manufacturing
Science and Engineering, Trans of the ASME, May 2002.



Shah, SS., Endsley,
EW.,
Lucas, MR, and Tilbury D.: Reconfigurable logic control
Proceedings of the American Control Conferenc
e, May 2002.