Chapter 4 Introduction to Automation

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Chapter 4Introduction to Automation

• Kanchala Sudtachat

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Contents

• Basic elements of an automated system
• Advanced automation function
• Levels of automation

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Defining

• Automation is the technology by which a process
  or procedure is accomplished without human
  assistance.
• It is implemented using a program of instructions
  combined with a control system that executes the
  instructions.
• ????????????????????????????????????? ?????????
  power ??????????????????????????????????????????
  ???? ?????????????????

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Automation
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Basic elements of an automated system

1. Power to accomplish the process and operate the
   system.
2. A program of instructions to direct the process.
3. A control system to actuate the instruction

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Elements of an automate system
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Power to accomplish the automated process

• Power for the process ???????????????????????????
  ???????????????????????????????
• ??????????????????????????????? ??? ????????????
  ??????????????????????????????????????????
• ??????????????? ??????????????????????????????????
  ????
• ??????????????????????????????????????? ??????,
  ????????, ???, ???????? ?????????????????
• ???????

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Power to accomplish the automated process

• Power for the process the power source for each
  operation is usually converted from electricity.
• Other power for automation fossil fuels, solar
  energy, water and wind.
• Power sources are used to drive the process
  itself, electrical power is used for the controls
  that automate the operation.

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Power to accomplish the automated process

• Process ??????? ??????????????????????????????????
  ???????? work unit
• Power is required for the following material
  handling function
• Loading and unloading the work unit.
• Material transport between operation.

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Power to accomplish the automated process (cont.)

• Power for Automation power is used for the
  following functions
• Controller unit
• Power to actuate the control signals
• Data acquisition and information processing
  ??????????????????????????? (process)
  ?????????????????????? ???????????????????????????
  ?????????? ???????????????????????????????????????

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Program of Instruction

• ???????????????? ?????????????????????????????????
  ??????? ??????????? product ??????????
  ??????????????????????? work cycle
• ???????????????????????? ????????????????? work
  cycle
• ???????????????? ????? product ???????????????????
  ?????????????? Work cycle
• The particular processing steps for the work
  cycle are specified in a work cycle program.

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Program of Instruction

• Work cycle program
• ????????????????????????????????????
  ????????????????? parameter ????????????
  ?????????????????
• ??????????????? ?????????????????????????
  ????????????????? load, unload ???
  ???????????????????????????? work cycle program
• Work cycle program ?????????????????????????????
  ??????????????????????????????????????????????????
  ?? ???????????????????????? ??????????????????????
  ????????

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Program of Instruction

• Process parameter
• ??? input ???????????????????????????????
• ???? ????????????????????????????????????????
  heat treatment, ?????????????? (x, y)
  ????????????????????????????????????
• Process variable
• ??? output ??????????????????????
  ??????????????????????????????????????????????????
  ?

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Program of Instruction

• Work cycle program
• Ex. single process parameter Maintain the
  temperature of a furnace at designated value for
  the duration of a heat treatment cycle.
• The single-step process is defined by more than
  one process parameter.
• Ex. Both temperature and atmosphere are
  controlled.

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Ex 4.1 An Automated Turning Operation

• The work cycle consists of the following
  steps(1) load starting workpiece, (2) position
  cutting tool prior to turning, (3) turn, (4)
  reposition tool to a safe location at end of
  turning, and (5) unload finished workpiece.
  Identify the activity and process parameter in
  each step of the operation.

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Program of Instruction

• ??????? ?????????? Hardware ?????????????????????
• ??????????????????????????????????????????????????
  ?? ?????????????????????????? batch production
• ????????????????????????????? ?????????????
• ??????????????????????????????????
  ??????????????????????????????????
  ?????????????????????????????????????

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Decision-Making

• Decision-Making in the programmed work cycle
• Operator interaction
• Ex ?????????? ????????????????????????????????????
  ???????????????????????
• Different part or product styles processed by the
  system
• Ex ???????????????? robot ????????? body ??? car
  ??????????????????????????????????????????????????
  ?????????????

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Work cycle

• ??????????????????????? ??????????????????????????
  ????????????????????? ?????????
• Number of steps in work cycle
• ??????????????????????????????? work cycle
  ???????????????????
• ?????????????????????? discrete production ????
  (1) load (2) process (3) unload
• Manual participation in the work cycle

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Work cycle

• Manual participation in the work cycle
  ?????????????????????????????????????? work cycle
• Process parameters
• ??????? process parameter ????????????????????????
  ?????????????????????????? parameter
• ??????? continuous ???? discrete
• ???????????????????????????????????????????

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Work cycle

• Operator interaction
• ???????? ?????????????????????????????????????????
  ??????????????????????? work cycle ???????
• Variations in part or product styles
• ???????????????????????????????????????????????
  work cycle ???????
• ??????? mass production (fix automation), batch
  production (programmable automation) ????
  different part / product styles (flexible
  automation)

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Control System

• A closed loop control system, also know as a
  feedback control system,
• is one in which the output variable is compared
  with an input parameter.
• Consists of six basic elements (1) input
  parameter, (2) process, (3) output variable, (4)
  feedback sensor, (5) controller and (6) actuator

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Control System

• (1) input parameter ???????????????????????
  ???????? ??????????????????? output
• (2) process ???????????????? ??????????????????
• (3) output variable ????????????????????????
  ??????????????????????????????????? ????
  ????????, ???, ???????????
• (4) feedback sensor ????????????????? output
  ?????????
• (5) controller ??????????? output ??? input
  ??????????
• (6) actuator ???? hardware ?????????????????

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A feedback control system
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Control System (cont.)

• Open loop control system operates without the
  feedback loop and without measuring the output
  variable.

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Control System (cont.)

• Open loop control system usually appropriate when
  the following conditions apply
• The actions per formed by control system are
  simple.
• The actuating function is very reliable
• Any reaction force opposing the actuation are
  small enough to have no effect on the actuation

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Control System (cont.)
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Advanced Automation Functions

• ??????????????????????????????????????????????????
  ????? ?????? work cycle ???????????????????
• ???????????????????????? safety, performance of
  equipment ????????????????????????
• Safety Monitoring
• Maintenance and repair diagnostics
• Error detecting and recovery

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Advanced Automation Functions

• Safety Monitoring
• To protect human workers in the vicinity of the
  system.
• To protect the equipment associated with the
  system.
• The safety monitoring is programmed to respond to
  unsafe condition.
• (1) Complete stoppage, (2) Sounding an alarm
• (3) Reducing speed, (4) Taking corrective
  action

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Advanced Automation Functions

• Maintenance and Repair Diagnostics have three
  modes of operation
• Status monitoring
• Failure diagnostics
• Recommendation
• Status monitoring serves two important functions
  in machine diagnostics (1) providing information
  for diagnosing a current failure, (2) providing
  data to predict a future malfunction or failure

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Advanced Automation Functions

• Error Detection and Recovery
• The error detection step uses the automated
  system s available sensor system to determine
  when a deviation or malfunction has occurred
• The possible error can be classified into
• Random error
• Systematic error
• Aberrations

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Advanced Automation Functions

• Error Recovery the types of strategies can be
  classified as follows.
• Make adjustments at the end of the current work
  cycle
• Make adjustments during the current cycle
• Stop the process to invoke corrective action
• Stop the process and call for help

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Levels of Automation

1. Device level
2. Machine level
3. Cell or system level
4. Plant level
5. Enterprise level

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Levels of Automation