COMPUTER CONTROL

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COMPUTER CONTROL

• Year 11

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Lesson 1

• Introduction to Computer Control

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Starter
Computer Control?
Write down as many things as you can to do with
computer control
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Uses of computer control
List down uses of computer control in your booklet
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COMPUTER CONTROL

• Computer control is where a computer controls a
  device in order to make something happen
• In order to do this it must have some data to
  process. Data can be collected by sensors and
  relayed to the computer automatically.
• The information that the sensors give back will
  allow the computer to make a decision about what
  to do next

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INPUT PROCESS - OUTPUT

• There are three stages of a control system are
• INPUT PROCESS OUTPUT
• Input the means of getting information into the
  computer
• Process instructions for the computer to do
  something with the input
• Output it then has to be able to alter
  something in the outside world

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FEEDBACK

• Feedback is essential for any computer-controlled
  system
• Feedback is where sensors continually send
  signals back to the computer to let it know what
  it is doing
• This is useful when a certain set of conditions
  needs to be constantly maintained

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FEEDBACK

• For example, a robot needs to navigate around a
  maze.
• A touch sensor is used to let the robot know it
  has hit a wall.
• This feedback may then tell the control process
  to reverse the robot and change direction.
• The process is repeated many times.

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INPUT
OUTPUT
PROCESS
FEEDBACK
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Task
In groups you will look at a specific work place
and research its use of computer control. In your
booklet you will need to design a storyboard to
show the main pieces of information you have
found out.

• Hospital
• Car Factory
• Theme Park
• Cinema

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Plenary How good is computer control?
Why do you think it took me 2 hours to get out of
a car park?

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Advantages of Computer Control

• Computers can operate 24 hours a day without a
  break
• Identical tasks can be easily repeated
• Very accurate
• Data is processed quickly, response can be rapid
• Can be used in dangerous places
• Can consider hundreds of inputs at one time
• Usually inexpensive to run no wages to pay

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Disadvantages of Computer Control

• Adding a computer to a control system is
  expensive
• To run properly needs software more expensive
• Sensors and actuators makes the system more
  complicated less reliable than a simple human
  operated system
• Only as good as the control software if
  anything unexpected happens, a person is much
  more flexible

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Review of learning

• What were the aims of the lesson?
• What did you achieve?
• What have you learned?

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Lesson 2

• Flow Charts

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Flowcharts

• These are often the easiest way to visually show
  processes in a computer system

Symbol Meaning
Start/End The terminator symbol marks the starting or ending point of the process. It usually contains the word "Start" or "End."
Action or ProcessA box can represent a single step ("add two cups of flour"), or an entire sub-process ("make bread") within a larger process.
DecisionA decision or branching point. Lines representing different decisions emerge from different points of the diamond.
Input/OutputRepresents material or information entering or leaving the process, such as customer order (input) or a product (output).
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Flowcharts
Symbol Meaning
Flow LineLines indicate the sequence of steps and the direction of flow.
Data storageIndicates a step where data gets stored. For Example "Save Orders"
DelayIndicates a delay in the process. For example "Wait 1 day"
Sub-Routine An independent program segment separate from the main program that performs a specific task
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Advantages and Disadvantages of Flowcharts
Advantages Disadvantages
Flowcharts are good way to communicate the details of a process to all concerned. Flowcharts can help people analyse problems or bottlenecks in a process Flowcharts are an excellent way of documenting a process In software development, flowcharts act as a guide or blueprint for the programmer. Flowcharts enable an organisation to have a record of standard business processes. Some processes or programs are so complex that it becomes difficult to represent them clearly in a flowchart. If an alteration needs to be made to the system, the flow chart usually needs to be redrawn. If it is a complicated flowchart, this can require a lot of work. People need to understand what the flowchart means and what the different symbols represent. You cannot give a flowchart to a complete novice and expect them to understand it.
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ACTUATORS

• An Actuator is a device to which can convert an
  electrical control signal to a physical action.
• For example, in a greenhouse, the data from the
  sensors tell the computer that the temperature is
  too hot. The computer sends a signal to the
  actuator which causes the motor to open the
  window.

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Task

• Using Flowol you are going to create a flowchart
  for the barriers on the car park

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Task

• Then move onto the theme park ride

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Plenary

• Print screen one of your finish flow charts into
  your booklet and annotation it to explain how it
  works

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Review of learning

• What were the aims of the lesson?
• What did you achieve?
• What have you learnt?

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Lesson 3

• Data Logging
• Sensors

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SENSORS

• Sensors are used to detect and measure physical
  quantities such as
• Temperature
• Pressure
• Sound
• Light
• Humidity

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ANALOGUE DIGITAL

• Sensors can send two types of signal to a
  computer digital and analogue
• Digital signals can only have two values on (or
  true) and off (or false)
• Analogue signals can have any value

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ANALOGUE DIGITAL

• A computer can only deal with digital signals, so
  to be able to process analogue signals sent to it
  by a sensor the computer needs an
  analogue-to-digital converter (ADC)
• This device converts analogue signals, which
  computers cant process directly, into equivalent
  digital signals which they can process

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ANALOGUE SENSORS

• LIGHT SENSORS
• Light sensors can detect how bright a light is
• They can be used to automatically turn a light on
  when it gets dark and off when it gets light
• HEAT SENSORS
• Heat sensors can detect and measure heat
• They can automatically turn a heater on for
  example when the temperature is below a set value
  and off when it reaches a different value

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ANALOGUE SENSORS

• INFRA-RED SENSORS
• These are used to detect movement
• They can be used to turn on lights on your drive
  when someone approaches your house, or detect
  movement as part of a burglar alarm
• SOUND SENSORS
• Detect how loud sound is
• Could be used to detect how loud noise that comes
  from a building is, for example

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ANALOGUE SENSORS

• TOUCH SENSORS
• Can be used to detect if an object is touching
  something
• For example, if an automatic hoover touches the
  wall
• HUMIDITY SENSORS
• Measures how much moisture there is in the air or
  soil
• Used where it important to make sure that the air
  or soil isnt too dry or too wet

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ANALOGUE SENSORS

• PRESSURE SENSORS
• Are used to detect when there is a weight on
  something
• They can be used to detect cars driving down a
  road or the depth of rivers