Computer Control

Computer Control

1. The computer is used to run the control program. A computer is a processor or microchip embedded with equipment

2. Sensors

   • Measure some physical quantity within its environment
   • A heat sensor measures the temperature of a room or a pressure sensitive mat
   • Once the reading is taken, it will send it back to a computer

3. ADC

   • Computers need digital data which consists of 1's and 0's
   • It is converted from an analogue signal to a digital
     • An analogue to digital converter is needed

4. Process

   • The data will be compared against a set of rules which have been programmed into the control system and a decision will be made

5. Output

   • Once a decision has been made, it will send the correct signal to an output device

6. Open loop system

   • Open loop system
     • Only looks at input data
     • Very simple, based on a command
   • Feed back system
     • More precise control
     • More complicated to make
     • Output of the system affects the input

7. Actuator

   • Mechanical device or motor which carries out the action made by the control system
   • E.g camera zoom

8. Examples

   • At home
     • Washing machines, microwave, dishwashers, video recorders
   • At work
     • air conditioning. lifts, factory robots
   • Outside home
     • Traffic light systems, car park barriers, lifts

9. Advantages

   • 24 hours
   • Work without holidays
   • Accurately repeat actions
   • Processes data from sensors very quickly
   • Accurate, reliable desicions

10. Disadvantages

    • Cost a lot money
    • If computer malfunction it may not work
    • Power cut
    • Cannot react to certain events
    • Prefer people