Topic 7) Control Flashcards
What is a Control System?
A device, or set of devices that control, manage, command, direct or regulate the behaviour of other devics or systems.
What are the Advantages of Control Systems?
Computers can respond much more quickly than humans
Control systems can run without breaks (24 hours, 365/366 days a year)
Control Systems are less error prone than humans
Control systems can be planed in an environment hazardous to humans
What are the Disadvantages of Control Systems?
Technical Malfunctions can occur
Cannot react to unexpected events
Relies on a consistent supply of electricity
Could be more expensive than a human solution
What are the components of Control Systems?
Microprocessors
Sensors
Actuators
What are Microprocessors?
An integrated circuit that contains all the functions of a computer’s CPU
Performs calculations and data processing
What is a Sensor?
A device which detects or measures a physical property and records, indicates or otherwise responds to it
What is an example of a Sensor?
Heat
Humidity
Infrared
Light
pH
Pressure
Smoke
Sound
Tilt
Touch
What is an Actuator?
Part of a device or machine that helps it to achieve physical movements by converting energy
A device that moves or controls a mechanism.
What are some examples of Actuators?
Opening doors on a bus.
Opening a car window.
Locking the car doors
What is a Transducer?
Converts one form of energy into another
True or False?
Sensors and Actuators are both transducers
True!
What are ADC Converters?
Analog-to-Digital converters.
They convert analog data from sensors into digital data, which can be read by computers.
What is IPO Model?
Input-Process-Output Model.
1) Sensors take in analog input and convert them into digital
2) Digital data is processed by the microprocessor, to output different digital data
3) Transducers turn this digital data into a form of physical motion
What is Feedback?
If either the output, or some form of it is utilised as part of the system input, then it is known as feedback.
What are some examples of Feedback Loops?
Open Loop System
Closed Loop System
Negative Feedback Loop
Positive Feedback Loop
What is an Open Loop System?
Doesn’t take feedback into account, repeats the same action over and over again based on an input.
ie, TV Remote Control, Light Bulb, Coffee Machine, Toaster
What is a Closed Loop System?
Takes feedback into account, including output and possible other factors that are external to the system
Corrects errors by using feedback loop to alter subsequent inputs
ie, Home Thermostat, Airplane Autopilot
What is a Negative Feedback Loop?
A system in which feedback is given in order to reduce fluctuation in subsequent output
Tries to move the output closer to the ‘target value’
ie, internal body temperature regulation
What is a Positive Feedback Loop?
Enhances or amplified changes in output to move a system further away from the ‘target value’.
ie, global warming
What is a centralised system?
All components within the system are controlled by a central processing unit.
What are the Advantages of centralised systems?
Easier to maintain and troubleshoot
More control
What are the disadvantages of centralised systems?
If main sensor/controller/actuator fails, the whole system fails
Less power
Less flexibility
What is a Distributed System?
Different components are controlled by a number of different processing units located throughout the system- all working towards a common goal
What are the advantages of a distributed system?
Shared processing load
More reliability
Flexibility
