Case study 5
Q1. How many different things did you count? What were they? In
what ways might computers be used to control different things in the
supermarket?
A1.10 different things. They are the microwave, GPS, gas fill
up, car park barrier, Car reverse sensor that goes beep, robot, automatic door,
freezer, conveyer belt, pays with the card. The computer controls the air conditioner,
the fans, the freezer, the lights, the conveyer belt, barcode sensor, automatic
doors and the room temperature.
Q2. Why is it useful to use computers rather than people to
control things? What problems might there be if any of the computer systems
fail in the supermarket?
A2. If we use people to control the machines
then it will be slower and it is too much for them to control. People will wait
for a very long time to get their turn in line.
Q3. Describe the inputs and outputs for the other devices that
we have talked about so far. How do the supermarket doors and car park barriers
know when to open? Identify other control systems that work automatically in
this way.
A3.
Microwave’s input
is set the time and output is cook food,Alarm clock’s input is set the time and
output is alarm on, Car barriers’ input is swap the card or punch the button, and
output is open the door, Supermarket door’s input is move to the door and
output is open the door.
Q4.What would happen if the instructions were wrong? These instructions
assume that the car is in the right place. What would happen if the car were
not there? How could they stop this happening?
A4.If the
instrument were wrong , the robot will
drop the wind shield and broke it. If the car was not there the robot will
automatically stop. They stop this happen by stop the machine.
