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© Boardworks Ltd 20041 of 12
ICT and Environmental Monitoring
ICT in Society
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Why monitor environments?
All kinds of environments can be monitored for different reasons:
people who work indoors will be more productive if the room is at a comfortable temperature and the air is neither too dry nor too humid
they will be safer if the building has fire and intruder alarms
rivers and soil can be monitored to check for pollution
public buildings need to monitor how many people are inside them in case of emergencies
greenhouses and industrial processes often need controlled levels of temperature, moisture or acidity.
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Network server room
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Sounding the alarm
Some sensors, like smoke alarms, have a fixed threshold. Others, like temperature, can be set by the user.
Sensors are located in or around the server room.
Each sensor monitors a different condition, e.g. temperature, humidity, smoke, floodwater, mains power etc.
When the condition crosses a set threshold, the output state changes to abnormal.
That triggers an alert, which could be an alarm sounding or a message sent to a mobile phone to tell someone there is a problem.
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© Boardworks Ltd 20046 of 12
Shopping centres
Modern shopping centres monitor their environment very carefully. They need to know:
how many cars are in the car parks
They also need to be able to respond quickly in emergencies such as fires, because there are a lot of people in an enclosed space.
how many people are in each part of the centre
whether the temperature and humidity levels are comfortable for shoppers.
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Case study – Bullring Centre
The Bullring Centre in Birmingham opened in 2003 at a cost of over £500 million. It controls:
3,100 car parking spaces140 shops and110,000 square metres of retail space.
On its opening day it had 276,600 visitors.
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People tracking
Tracking people as they move around shopping centres is important for many reasons:
measuring how successful the centre is
mapping the routes people take; this helps to plan which shops and attractions go where
finding out how long visitors stay
making sure the visitor numbers aren’t too high for safety.
The path of shoppers inside a store can be tracked by fitting sensors to each trolley or basket.
I’m the sensitive type
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The traditional way of counting people was to use a light beam sensor and count how many times it was broken.
Did you know that………Most people getting off an escalator turn left?
The problem with that method is that if two people walk through it side by side, it only counts one.
Infra-red sensors mounted above each entrance can count how many people go through and which way they turn.
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Greenhouses
Commercial food growers need to be able to control the climate that their crops grow in.
They can control:
temperature: using heat sensors that turn heaters on and off or open air ventsthe moisture of the soil: watering systems can be turned on and off by moisture sensorsthe amount of light the plants receive: lighting can be turned on or off, or blinds lowered or raised either by timers or light sensorsthe humidity: if the air is too dry, water can be sprayed into it.
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Sensors and thresholds
Thresholds are limits which trigger certain actions.
Switch on heater
Temperature below 20oC ?
Temperature above 25oC ?
Yes
NoIs heater on ?
Switch off heaterNo
Yes No
Yes
Start
A more complex system would open and close vents too.
Imagine a particular plant grows best between 20 and 25°C. The heater would be controlled like this:
To ventilation
system
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Summary
All kinds of environments can be controlled for different reasons.
Sensors can be used to monitor different conditions including light, temperature, humidity, smoke, floodwater and mains power.
Certain sensors have a fixed threshold, others can be set by the user.
Crossing the threshold triggers an alert.
The alert can be auditory (for example, sounding an alarm) or visual (for example, a message on a screen), or it can make an event occur (for example, opening a vent or turning sprinklers on).
