Topic 7: Control Flashcards
(11 cards)
Discuss a range of control systems.
Control systems are input, process, output systems; an input is provided to the system, it is processed by some algorithm, and an action is performed. Examples include heating systems, taxi meters, elevators, washing machines, device drivers, GPS systems, traffic lights. Know how these systems work at a high level.
Outline the use of microprocessors in control systems.
Microprocessors are used to receive data from a sensor, process it according to an algorithm and perform some action. Many control systems use embedded “microcontrollers”, stand alone chips that are designed to perform a specific task that do not include a whole computer system.
Outline the use of sensor input in control systems.
Converts physical, often analog data (such as speed, temperature, humidity, pressure, distance etc) into discrete digital signal using an analog-to-digital convertor (ADC) that can be read by the microprocessor.
Evaluate different input devices for the collection of data in specified situations.
Some main sensor types are: sound, motion, vibration, optical/image, pressure, temperature, or proximity.
Define transducer.
A device that converts one form of energy to another. In computer systems, transducers convert physical quantities (speed, temperature, humidity, pressure, etc.) into electrical signals and vice versa. Sensors can be described as transducers.
Define actuators.
A type of transducer that receive some form of energy (usually an electrical current sent from a microprocessor) and convert it into some kind of motion. For example, a mechanical motor that moves an automatic door is an actuator.
Describe the relationship between a sensor, the processor, and an output transducer (actuator).
A sensor senses continuous, physical analog quantities, transforms them to digital signals which are input to the processors. These are processed according to some algorithm, and output an electrical signal (using a digital to analog convertor to convert the digital signal to an electical one) to an output transducer (acutator) which converts the electrical signal into motion.
Describe the role of feedback in a control system.
Feedback refers to the process where the output of a control system affects the part of the new input to the system. For example, a heating system detects the temperature (input) and heats the room (output) accordingly. The output has an effect the input.
Discuss the social impacts and ethical considerations associated with the use of embedded systems.
Consider examples like: electronic tagging (tagging prisoners), surveillance
Compare centrally controlled systems with a distributed system.
In a centrally controlled system, a a dedicated computer is responsible for all necessary calculations. A centralized system usually has lower costs, greater security (all data is centrally stored), less adminstrative overhead, but also makes the centralized computer a point of failure (the whole system will fail if the centralized computer fails).
A distributed system has multiple computers, with each one performing part of the necessary calculations. Are more fault-tolerant and expandable. Usually more costly than a centralized system, backup is more complex, security is more difficult.
Outline the role of autonomous agents acting within a larger system.
Agents are anything that can perceive its environment, and act upon it. Autonomous agents have (1) reactive behavior; can sense the environment and react, (2) autonomy; can activate alone for a task/select the task without human supervision (3) persistence; runs continuously (4) socialy; can interact with other agents though communication
