Standard Grade Computing Studies Automated Systems

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Standard Grade Computing StudiesAutomated Systems
AutomatedSystems
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What is an automated system?

• An automated system is simply a system that
  takes an input, carries out a process and gives
  an output.

INPUT
PROCESS
OUTPUT
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Everyday automated systems

• Examples of everyday automated systems include
  ...

Washing Machines
Cameras
VCRs
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Industrial automated systems

• Examples of industrial automated systems
  include ...

Assembly Lines
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Why use automated systems?

• They can carry out tasks faster than humans.

• They can carry out boring and repetitive tasks.
  

• They can be used in places that are dangerous
  to humans.

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Why use automated systems?

• They can work efficiently without breaks.

• They can be programmed to carry out different
  tasks.

• They are more accurate than humans.

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Open loop control systems

• In an open loop system the processor is
  instructed to perform a repetitive task and
  doesnt stop until it has finished.

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More open loop control systems
Washing Machine
Toaster
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Closed loop control systems
Feedback

• In a closed loop system the processor receives
  feedback from a sensor, then decides how to
  perform a task.

Sensor
Decision?
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More closed loop control systems

• Burglar Alarms

• There are many different types of sensor that
  can be used for burglar alarms. All of them
  measure whether a person has entered or is about
  to enter a room. The most popular types of sensor
  for burglar alarms are door switches and
  infra-red detectors.

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More closed loop control systems

• Burglar Alarms

• Door switches are fitted somewhere around the
  edge of the door. When the door opens, the switch
  signals to the computer, which sounds the alarm.

• Infra-red detectors detect invisible infra-red
  light. All warm objects give out infra-red light.
  The detector constantly looks for any movement of
  infra-red light. When a burglar moves in front of
  the sensor it signals to the computer which
  sounds the alarm.

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More closed loop control systems

• Greenhouses

• Some greenhouses have computer-controlled
  equipment for growing crops such as strawberries
  all year round.

• Sensors measure the temperature inside the
  greenhouse. If the temperature is too high, the
  machine opens the windows.

• If the temperature is too low, the machine
  closes the windows and may switch on a heater.
  Watering, feeding and lighting can also be
  controlled automatically.

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Advantages of Automated Systems for Employers

• The quality of the product is consistent.

• The way processes are carried out can be
  changed if they need to be changed.

• Automated systems dont need comfortable
  conditions to work in (including eating and
  toilet breaks).

• Automated systems dont ask for wage rises.

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Advantages of Automated Systems for Employees
C

• More leisure time.

• Fewer industrial accidents.

• Working alongside automated systems with robots
  equipped with sensors is safer.

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Parts of a robotic arm
C
Elbow
Shoulder
Wrist
Waist
Gripper
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Controlling the robotic arm
C
INTERFACE
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Changing the end-effector on a robotic arm
Weve already spoken about computers being to use
different programs to make the robot carry out
different tasks. To really carry out different
tasks we need to use different attachments, or
end-effectors, on the arm.
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Mobile robots

• Mobile robots are controlled by computer during
  their journey to fetch items.

• Although programs tell the robot which way to go
  they have to be guided.

• One way to guide the robots is to detect
  magnetic fields given off by wires under the
  floor.

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Mobile robots

• Another way to guide the robot is to use white
  lines on a black floor.

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Mobile robots

• Sensors under the robot detect the white of the
  line. If black is detected, it know it is off
  course and the wheels must turn to re-direct it
  again and find white.

W W
W W
B W
W W
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More sensors on mobile robots

• Impact sensors or infra-red sensors are also
  situated on the bumpers at the front and rear of
  the robot. If they detect a presence the feedback
  can instruct the computer to stop the motors of
  the robot immediately.

• Without the sensors the robot would continue and
  accidents would happen.

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Controlling mobile robots

• A program can be written that calculates the
  quickest way to a row of shelves in order to
  allow the robot to pick up items.

• A map of the warehouse can be used by the
  program. But, of course, the guidance system must
  be followed to complete the task - whether it be
  magnetic or light.

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Controlling mobile robots
C

• If the layout of the warehouse changes the robot
  can be re-programmed.

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Systems Analysis
F/G

• System analysis involves looking at how various
  jobs are done manually, and see if any of the
  jobs can be carried out more efficiently by
  computer.

• Once the computer has been installed and the job
  has become automated, we still have to monitor
  the process and find ways to improve the
  performance.

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Parts of a robotic arm and degrees of freedom
Elbow
Shoulder
Wrist
Waist
Gripper
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Different types of movement
F/G

• The different types of movement for the parts of
  a robotic arm can be described by the following
  ...

Pitch
Yaw
Roll
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Controlling the robotic arm with an open loop
Digital to Analogue Converter
0 1 1 0 1 1 0 0
INTERFACE
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Controlling the robotic arm with a closed loop
F/G
Sensors on gripper send feedback on pressure
Analogue to Digital Converter
0 1 1 1 1 1 1 0
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Control programs

• The control programs are usually written in a
  control language specially designed for robot
  control. They have commands that relate directly
  to the robot world ...

GRASP
TURN
MOVE
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Control programs
F/G

• The control programs for mobile robots are
  stored on ROM chips on the mobile robot itself.

• This means that the mobile robots can still keep
  the information and program even if the power is
  off.

• It also means that the programs can be loaded
  very fast when the mobile robot is activated
  again at Power On.