4.4 Computer Control & Data Logging Flashcards
Define sensor.
An input device used to measure a change in almost any physical quantity in environmental conditions.
State 3 types of sensors.
- Light sensors measure light intensity
- Temperature sensors measure temperature changes
- Sound sensors measure the level of noise
Define data logging.
The automatic capture of data at regular time intervals without human intervention, which can then be stored on a computer and analysed.
What is an ADC?
Analogue to Digital Converter - changes analogue data into digital data.
What is the difference between analogue and digital data?
Analogue data is a continuous, varying voltage whereas digital signal is a binary pulse. Computers can only understand digital data.
Define feedback.
A situation where the output can influence further inputs.
Summarise how a home heating system works.
If the temperature sensor says it is too cold the heating is switched on. This will lead to a rise in temperature. When the temperature reaches a certain limit the sensor will communicate this data to the computer and the output will result in turning off the heating.
What is an embedded computer?
A computer used to control a device in your home by using a microprocessor which is inside the device.
List 4 examples of embedded computer devices.
- Washing machines
- Burglar alarms
- DVD/CD players
- Microwave ovens
Explain how the embedded computer device works in a washing machine.
When the user selects a washing program, the microprocessor carries out a pre-stored sequence of instructions. The microprocessor will carry out activities like turning on and off switches for water intake and water outlet, and controlling the water heater and water pump. A number of sensors are used including water flow, temperature and door open/close.
What are the 3 main aims of traffic control computer systems?
- Keep traffic moving, particularly during rush hours
- Discourage speeding
- Manage car parking
Describe what is meant by vehicle actuation systems.
Systems in which traffic lights are programmed to vary in operation throughout the day. Eg traffic lights remain green for longer during busier times such as morning into the city and in the evening out of the city.
How is car park management carried out?
The system calculates the number of vehicles entering and leaving a car park at regular time intervals through use of sensors, and then display on large electronic signposts the number of empty spaces in a named car park.
Describe how speed control is carried out.
Sensors detect car speeds and if the speed is excessive, and a camera automatically takes a photograph of the car including registration number, speed, location, and time and date. All of these details are superimposed onto the photo, and the car owner can be detected and hence the police can issue a fine.
