Transcript Overview of EMU CIM LAB

Farnoush Farid 049457
Farinaz Farid 049458
Hani Jafari 044399
Mohammad H.S.Shirazi 058013
Shahrouz Pazouki 039035
The Computer Integrated Manufacturing (CIM) is
a manufacturing philosophy in which the functions
of the organization are designed and integrated into
computer control systems to achieve organizational
goals as efficiently and effectively as possible.
The Classic Model for Computer Integrated
Manufacturing typically splits the Control and
Monitoring functions of an Automation System into 4
discrete levels. These levels are shown in the next slide.
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In this presentation we will explain the
nomenclature of Programmable Logic Control
(PLC) as one of the levels of CIM model. We
will also give a brief introduction of EMU CIM
lab material handling system and its operation.
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The main focus of the EMU CIM
laboratory is on the integration of the design and
manufacturing functions in the computerintegrated manufacturing environment. This
laboratory is an educational laboratory consisting
of CNC machine, conveyors, electro-pneumatic
robots, A Programmable Logic Controller (PLC),
a bar code reader, optical and mechanical sensors
and a host computer. The system performs
different scenarios of manufacturing and material
handling. It also allows the students to write their
own scenarios. The main components of the
system are described in the following slide.
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PLC is a device invented to replace the
necessary sequential relay circuits for
machine control. The PLC works by checking
inputs and depending upon their state, turns
on/off its outputs. The user enters a program
via software, that gives the desired results.
Approximately in all the industries such as
machining, packaging, material handling and
etc. the PLCs are used. Almost any
application that needs some type of electrical
control has a need for a PLC.
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The operation of the PLC system is simple
and straightforward. The Process or CPU
completes three processes:
1) scans, or reads, from the input devices.
2) executes or "solves" the program logic.
3) updates, or writes, to the output devices.
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The PLC mainly consists of a CPU, memory
areas, and appropriate circuits to receive
input/output data. The PLC can be considered
to be a box full of hundreds or thousands of
separate relays, counters, timers and data
storage locations. These counters, timers, etc.
don't "physically" exist and they are simulated
and can be considered software counters,
timers, etc. These internal relays are simulated
through bit locations in registers.
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The CPU continuously Reads Inputs, Solves
Logic, and Writes to the outputs. The Input
system senses the status of the real world
inputs (a switch, a level, etc.), translates them
to values that can be used by the CPU, and
writes those values to the Input table. The
application program is executed, and writes
values to the Output table. The Output system
then converts the output value to a real world
change (motor turns on, valve opens, etc.).
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The process of reading inputs, executing
logic, and writing outputs is called the PLC
Scan or Sweep. This process is represented in
the next slide.
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A relay is an electromagnetic switch. After
a voltage is applied to the coil, a magnetic
field is generated. This magnetic field sucks
the contacts of the relay in, causing them to
make a connection. These contacts can be
considered to be a switch. They allow current
to flow between two points and as a result
the circuit is closed.
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A counter is a simple device intended to do
one simple thing - count. Using them,
however, is sometimes a challenge, because
every manufacturer seems to use them a
different way.
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2.
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It is an equipment that waits a set amount
of time before doing something. Here are
three types of timers:
On-Delay timer
Off-Delay timer
Retentive or Accumulating timer
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The automated system used in the CIM lab is
of the material handling type. A material
handling system controls the flow of parts,
mobile resources and waste. Historically
material handling system simply means the
handling of material during different
processes. Nowadays, material handling is
properly viewed as an integral part of the total
manufactured system.
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Material handling systems (MHS) are the
backbone of manufacturing.
Due to it’s cost and efficiency of operations,
designing or selecting a material handling
system is one of the most important and
challenging tasks a planner faces for
establishing flexible manufacturing.
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•Conveyor:
It moves the materials over a
fixed path. There are two conveyors used
in the existing system. The first conveyor
is belt type and the second conveyor is a
continuous loop type.
•Robots: The robots used in the CIM lab
are of the material handling type. They
are used to move the parts from one
place to another by rails or guided paths.
Robots are flexible and programmable.
•Sensors:
The sensors are located at the specific
points of the conveyor and they send logical signals
to inform the controller whether the part is a t the
correct handling position or not.
•Programmable Logic Controller (PLC): The PLC is
programmed to control the conveyor and pneumatic
robots with the feedback provided by the optical
sensors.
•Bar code reader: It is used to inspect and classify
the work parts carried by the conveyor.
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1.
2.
As it can be seen from the previous figure, the
primary system consists of four sensors. The
operation of each sensor is as follows:
The first sensor activates, when the part contacts
with it. It sends signals to the PLC so that the belt
conveyor starts to move.
The movement continues until the part reaches
the second sensor. At this point, the belt the
signal sent by the second sensor to the PLC
makes the belt conveyor to stop.
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3. The third sensor is activated, when ever the part is
dropped on the continuous loop conveyor. As
soon as this occurs, the conveyor starts to rotate.
4. The fourth sensor is a color sensor. This sensor
helps the system to detect and distinguish the
parts according to their color. The sensor color
used in the existing system is sensitive to the
white color.
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There are two robots used in the existing
system. They are as follows:
1.
The first robot is aimed to pick up the part from
the belt conveyor and place it on the continuous
loop conveyor or a storage box according to the
bar code read by the bar code reader.
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2. The second robot is the electro-pneumatic robot
having several arms. The robot is used to pick up
the part from the continuous loop conveyor
according to its color detected by the color
sensor.
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The primary system designed in the CIM LAB
had a disadvantage that even if a part required
only one of the specified processes and not the
other one, it was still required to travel along the
conveyor belt without having the other process.
Since this was inefficient and time consuming,
the primary system was then modified to
optimize the process in terms of time.
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As it is realized from the figure, in the
modified system a Linear Slide Base (LSB)
robot is used to handle the parts between
stations 1 and 2. The sliding base carries the
robot to the station, where the robot is
required to perform a pick and place
operation. When the part is placed on the
station 2, an optical sensor located at station 2
sends a feedback to the PLC. The PLC
actuates the sliding robot to move to station 2
and pick the part. The following slide
represents the sliding robot used in the
modified existing system.
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1.
2.
3.
The scenario employed by the existing
manufacturing system is follows:
After the part makes a contact with the first
sensor, the belt conveyor starts to rotate.
The bar code reader reads the part code while it
is moving on the conveyor.
As soon as the part reaches the first sensor, the
conveyor stops and the first robot either pick the
part and place it in the storage box or picks the
part and place it on the continuous loop
conveyor.
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4. If the part is dropped on the continuous
loop conveyor, the feedback sent to the
PLC by the second sensor makes the
conveyor to start the rotation.
5. The part keeps moving on the conveyor,
until it reaches the color sensor.
6. According to the signals sent by the color
sensor to the PLC, the pneumatic robot
either picks the part or leaves it to
continue its movement on the conveyor.
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7. After the part reaches to the optical sensor,
the sensor feedback actuates the sliding robot
to either leave the part to rotate on the
conveyor or picks the part and put it in the
station 2.
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In this presentation the PLC as the second
level of CIM structure is discussed. Also the
material handling systems and the automated
material handling system present in the EMU
CIM lab have been briefly introduced.
Several modifications can be performed in
order to improve the capabilities of the lab and
make it more efficient and feasible.
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