How organisations use ICT
Control Systems
A control system is one where a microprocessor is used to control various physical conditions.- Control systems have an ancient history where Roman engineers maintained water levels in aqueducts by means of floating valves that opened and closed at appropriate levels.
- James Watt's flyball governor (1769) regulated steam flow to a steam engine to maintain constant engine speed despite a changing load.
The introduction of analogue and digital computers opened the way for much greater complexity in automatic control theory. What this section does is to examine how computers are used in practice. In all cases, it is important to understand the concept of using sensors to convert analogue signals to digital data for processing. Conversely, devices enable digitized data to be converted to an analogue signal such as switching a device on or off.
The following section components much be studied with questions to answer at the end of each:
- Maintaining constant physical conditions
- Car manufacture: Industrial robots
- Medical applications: Intensive care
- Process control
Section 2 – How organisations use ICT
Control Systems
This section will end with the following test:- Describe the use of ICT given a scenario
- Identify the hardware required for that use
- Identify the software required for that use
- Consider further applications
Case #1: Air Conditioning Systems
Air conditioning units contain a special chemical called a refrigerant, which has the unique ability to change from a gas to a liquid in a short amount of time and back again. A refrigerant called freon is commonly used in air conditioning units, although there are other commercial refrigerants available. The refrigerant is pumped into the air conditioning unit at the factory, along with a small amount of lubricating oil for the compressor, an essential part of the air conditioning process.
Outside the building is a unit called a Condenser – a set of coils /
/ Inside the building is an evaporating unit
Air conditioning begins with the refrigerant entering the compressor, usually located at the bottom of the unit. At this point, the refrigerant is a cool gas. As the gas enters the compressor's inner chamber, the compressor squeezes the refrigerant and the gas becomes a very hot gas under high pressure. This hot gas goes through a series of condensing coils placed outside of the room being cooled. The heat dissipates into the outside air, much like a car's radiator dissipates heat from the engine coolant. Once the refrigerant reaches the end of these coils, it is significantly cooler and in liquid form.
This liquid is still under high pressure, like the contents of an aerosol can.
The liquid refrigerant is forced through a very tiny opening called an expansion valve. The liquid refrigerant comes out of the other end of the expansion a very small amount at a time. Because the refrigerant evaporates at a much lower temperature than water, it begins to evaporate while travelling through another set of coils. This evaporation action that draws heat out of the surrounding air, including the air contained in the room. The air conditioning unit's fan blows across metal fins placed over these coils, causing the sensation of cooling in the room.
At this point, the liquid refrigerant has become a cold gas again and re-enters the compressor, where the entire process begins again until a thermostat registers a specific temperature and shuts off the compressor.
The key use of computing is through the use of SENSORS
When the room warms up, the thermostat senses (via sensors) the added heat and the compressor kicks back on to create more of the hot pressurized gas. At some point, the temperature of the room may equal the cooling power of the air conditioner and the compressor will shut off again. This, then requires TWO sensors – one to measure the room temperature and the other the cooling power temperature. The sensors collect these analogue signals and relay a digital signal back to the Air Conditioners CONTROL UNIT which, in turn, controls the physical switches through Digital-Analogue switch devices.
The actual temperature that the user wants can also be set, which will require some sort of user interface. This can also be digital if a touch screen input device was installed. The temperature settings would have to be sent to the control unit of the air conditioning unit so that there is a basis for decision making.
The air conditioning systems of most building do benefit from energy-saving steps such as using window shutters or blinds and keeping doors closed, since they don't have to work as hard to keep the room at an acceptable level of cool. /
Case #2: Central Heating Systems
Computers have a major role in keeping a property warm. Although this is not a major application in a country like Egypt, it is common in colder climates such as the UK.
An average, ordinary modern domestic heating system has the following major components.
- The boiler is used to heat the water needed by the whole system.
- The Programmer contains a clock and two time switches (channels) which turn the hot water and central heating services on and off at pre-selected times of day (or night).A computer device is used here to keep time and, when required, use switches to turn the heater in the boiler on and off.
- Once the system is turned 'on' by the programmer, the boiler will be turned on and off by either the "room thermostat" and the "hot water cylinder thermostat". Each thermostat will turn the boiler on when heat is needed, then turn it off again when it isn't. Again, a computer device will be used to switch the be used to control the switch.
- Radiators are fitted around a property and this simply holds hot or cold water. It is the hot water in the pipes and radiators that warms the property.
A Hot water cylinder is used to store hot water and this temperature is regulated to the right temperature. A pump is then used to pump water around the pipes and through the radiators. The pump is switched on and off with the help of a computer device.
And here are a few other things you should know:
The water in the boiler is separate from the water that comes from your taps. Heating system water goes around and around the boiler and radiators indefinitely, until it is drained out by a heating engineer for one reason or another... This slows down internal corrosion, and also allows the circulating water to be dosed with inhibitor to completely prevent internal corrosion. In advanced systems, computer devices can monitor the state of the water in the pipes and the amount of corrosion.
The hot water cylinder has a long coil of pipe inside, through which the boiler water flows. This is how the boiler water is kept separate from the domestic water. Heat is transferred through the wall of the pipe into the water in the cylinder.
The control knob on the front of your boiler sets the temperature of the water it produces, and this is the temperature your radiators will be when your heating is 'on' – a digital device interfaces with the use and an analogue device are the switches. This control also needs to be set so the boiler delivers water at a higher temperature than set on the cylinder thermostat, or the cylinder will never reach the selected temperature and the cylinder thermostat will never shut the boiler down. Again, computers can measure and compare the two temperatures.
Modern boilers often have a "pump over-run" facility. This can be puzzling to users getting to know their system. The pump continues to run for a few minutes after the boiler has been turned off. It removes the risk of static water in the heat exchanger being boiled by residual heat immediately after the gas flame is extinguished, and extends heat exchanger life.
Case #3: Refrigeration Systems
A Refrigeration unit works the same way as an air conditioning unit.
The condensing unit is outside of the fridge – usually behind it
The evaporating unit is inside the fridge
The main input device are:
- A temperature sensor which can monitors the temperature inside the fridge
- A pressure sensor for the door
- A number pad or something similar for the user to set the desired temperature
A Control Unit is used to collect the temperature from the temperature sensor. It compares this to the pre-set temperature entered by the user. So,
IF(the temperature of fridge) is higher than(input pres-set temperature) THEN(activate the ACTUATOR to switch Compressor ON) ELSE (activate the ACTUATOR to switch Compressor OFF)
Here is another piece of logic for the light switch in the fridge
IF(the door sensor) equal (DOOR IS OPEN) THEN (activate the ACTUATOR to switch fridge light ON) ELSE (activate the ACTUATOR to switch fridge door light OFF)
Questions to Answer
- For each of the cases above, describe how the following input devices may be used:
- Temperature sensor
- Moisture sensor
- Pressure sensor
- Light sensor
- In Case 3, an IF..THEN..ELSE type of logic has been set out to describe how control units can conrol the temperature and lighting in a fridge. Use exactly the same kind of logic to describe:
- How the Air Conditioning Unit can control temperature in a room, and
- How a control unit can prevent the water in a boiler from exceeding a temperature of 90oC
AS Applied ICT
Section 2 – Part A
How organisations use ICT
Car manufacture: Industrial robots
After Henry Ford invented the assembly line, the construction of automobiles, cars and trucks remained unchanged throughout most of the 20th century. In the 1980s, however, the process underwent another dramatic change: the introduction of robots to perform jobs once reserved for humans.Significance
Robots were initially retained to perform precise welding chores and other repetitive tasks that humans had long found boring, monotonous and injurious. By using robots to weld, handle dangerous objects and place items, auto manufacturers were able to ensure a consistent product with a minimum of worker injury. Currently, 50 percent of all robots in use today are used in automobile manufacture.
How it works
To make a robot work, a computer program is installed on its controller computer. This provides a set of precise instructions--based on geometry and carefully timed--that tells the robot where to place things, how to rotate them, where to weld and how to perform all of its other functions.
Robots also can work in more extreme environments on their own, or they can work alongside humans, assisting them in their day-to-day jobs--such as moving or rotating a car so humans can work on parts of it that would normally be difficult to reach.
Robots do not think for themselves, and must rely on humans to provide instructions – they need to be programmed
Types of Robot
Almost all manufacturing robots are single arms with computer controls, and do not look like a typical science-fiction "robot." Different robots will have different appendages, depending upon their job(s). For instance, a robot that places windshields will have a vacuum-powered suction grip to handle the smooth glass, while a welding robot will have an arc welder to fuse two pieces of metal together.
Benefits
Robots have been a boon to the auto-manufacturing industry. They have significantly reduced worker injuries, including repetitive stress injuries and more significant mishaps that can do major harm. Additionally, the robots turn out a more consistent product at a significantly cheaper cost than can humans. In the 1970s, American auto manufacturers were maligned for the poor quality and bad engineering of their vehicles. Currently, robotic-assisted auto manufacturing allows a car to be made with much more precise welds, closer tolerances and more accurate engineering overall than could be achieved with human help. Finally, robots save on the cost of labor: There are no sick days, strikes, work slowdowns or other problems that can crop up with humans. Robots can, in fact, work around the clock with a minimum of human supervision.
The Future
As manufacturing becomes more automated, there will be less need for human workers in the auto industry. Currently, humans still work alongside robots for many reasons, most important of which is the ability of people to reach areas the larger robot arms cannot. As robotics technology improves, it is conceivable that the auto industry will become fully automated or employ human workers only sporadically. In the future, positions in the auto-manufacturing industry (at least in production facilities) will probably entail dealing with the robots themselves and not the cars or trucks; repair, programming and maintenance of robots will still need to be done by humans.
Links to click on:
- A youtube demonstration of a robot
- How Robots Work
- RobotWorx - End-effectors
Questions to answer
- Identify and explain both Input Devices and Output Devices of a Robot
- How is a robot programmed – identify TWO methods
- With the help of the second link above (How Robots Work) name SEVEN tasks that a robot can perform on a car manufacturing production line
- Identify FIVE different end-effectors used in car manufacturing.
Section 2 – How organisations use ICT
Medical applications: Intensive care and SurgeryHere are some of the basic uses that ICT in medicine can be applied to:
- Computerised storing of patients records - more secure and less likely to go astray
- Databases of organ donors
- Computerised devices such as pacemakers, artificial organs and limbs
- Computerised monitoring devices on patients
- Software to help diagnosis (Expert System/knowledge base)
- remote operations (see Robot Surgeon case study)
- Computers can model the effect of new drugs (see Deeper Blue case study)
Intensive Care
With respect to INTENSIVE CARE there are more specific uses.
Monitoring is the main use where sensors are used as input devices capable of collecting ANALOGUE signals and through Analogue to Digital conversion, can send data to a computer for further processing. Typically, sensors can monitor:
Blood Pressure
Pulse Rate
Body Temperatures
Pre-set values are normally programmed into the computer and should a sensor send back a signal outside of these pre-set ranges, an exception report is made such as alarm being set off.
The processing is superior to humans doing the work in that:
- Monitoring is constant 24/7 with no breaks
- It is far more accurate
- Feedbacks are more frequent – seconds rather than minutes or houre
- Response times are better
Keyhole Surgery
Keyhole surgery, which is also known as ‘minimally invasive surgery’, has sometimes been referred to as the greatest surgical advancement since anaesthetic since its introduction which came about as information technology made tiny cameras which could be inserted into the body working alongside computers possible.
There are many different types of conventional surgical procedure which can now be performed using keyhole surgery and the benefits to the patient are quite significant. These include less:
- Pain
- Minimal scarring
- Quicker recovery post operation and a faster resumption of normal everyday activities.
Depending upon the area of the body where keyhole surgery is being performed, about 3 or 4 tiny incisions (sometimes even fewer), usually only around 10mm each, are made into which a special channel or tube is inserted. This is known as a ‘port’ and via this port, a special viewing instrument called an endoscope is passed through.
This will have a powerful light source on the end of it and will work like a telescopic camera projecting images from inside the body onto a TV monitor which the surgeon can look at so that he can see exactly what the problem is and what needs to be fixed. In addition to the camera, the surgeon can also pass one or a series of specialised, miniature surgical instruments through either the same port or a different port (which would require a further incision(s) depending upon the procedure which is being carried out.
The technology means that the surgeon can operate the equipment from outside of the body whilst looking at the monitor (output). Endoscopes vary in size and design depending upon the area of the body which is being operated on.
Questions to Answer
Consider further applications in medical care by some research and write up a report on the benefits that ICT has brought to the following:
- Dental Care
- Pharmacy
- Medical Research
AS Applied ICT