Lesson 8 control and robotics

Lesson 8: Control and Lesson 8: Control and roboticsrobotics

Technology: 3Technology: 3rdrd ESO ESO

IndexIndex

Control Control systemsystem: : definitiondefinition TypesTypes ofof control control systemssystems PartsParts ofof a control a control systemsystem Robots: DefinitionRobots: Definition Parts of a robotParts of a robot Types of robotsTypes of robots

Control system: DefinitionControl system: Definition A control system is a device capable of controlling A control system is a device capable of controlling

enviromental conditions. They normally detect an enviromental conditions. They normally detect an enviromental signal, compare it with a fixed value enviromental signal, compare it with a fixed value set by the user and act over it. set by the user and act over it.

Input signalControlSystem Output signal

Regulation signal


Regulation signal

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Types of control systems I: OpenTypes of control systems I: Open1: open (ciclo abierto)1: open (ciclo abierto)The performance of the system over the enviromental The performance of the system over the enviromental

condition has not feedback.condition has not feedback.We use a clock (time signal) to start or stop the performanceWe use a clock (time signal) to start or stop the performance The system is quite simpleThe system is quite simple The control over the signal is quite poor. We are not sure The control over the signal is quite poor. We are not sure

we reach the required valuewe reach the required value


Regulation signal


Regulation signal

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Types of control system: Real timeTypes of control system: Real time

2 real time (ciclo cerrado)2 real time (ciclo cerrado)There is a feedback. The There is a feedback. The

output signal is detected output signal is detected by the control system an by the control system an converted until the set converted until the set value is reachedvalue is reached

The system is more The system is more complex and expensivecomplex and expensive

High performance. There High performance. There is accuraccy controlling the is accuraccy controlling the enviromental condition.enviromental condition.


Regulation signal


Regulation signal

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Parts of a control system (real time)Parts of a control system (real time)

Sensor (detector): It Sensor (detector): It registers the input signal registers the input signal and generates a prportional and generates a prportional electric signal electric signal

Regulator: It compares the Regulator: It compares the input signal with the signal input signal with the signal set by user. It generates a set by user. It generates a signal proportional to the signal proportional to the difference between themdifference between them

Actuator: This component Actuator: This component acts over the enviromental acts over the enviromental condition. Actuators can becondition. Actuators can be

I.I. Electric receivers: bulbs, Electric receivers: bulbs, motors, resistances motors, resistances (heating)(heating)

II.II. Pneumatic (air): mechanic Pneumatic (air): mechanic movements, weak and fastmovements, weak and fast

III.III. Hidraulic (oil): mechanic Hidraulic (oil): mechanic movements, strong and movements, strong and slowerslower

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RobotsRobots A robot is a mechanical or A robot is a mechanical or

virtual artificial agent, virtual artificial agent, usually an usually an electromochanical machine electromochanical machine that is guided by a that is guided by a computer program or computer program or electronic circuitry.electronic circuitry.

Due to its appearance or Due to its appearance or automatic movements automatic movements robot can convey a sense robot can convey a sense of intelligence or thougth of intelligence or thougth of its ownof its own

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Why would we use robots?Why would we use robots?

We use robots toWe use robots to Repetitive tasks, such Repetitive tasks, such

as welding, as welding, screwdriving…screwdriving…

Dangerous tasks, such Dangerous tasks, such as desactivating as desactivating bombsbombs

Activities which Activities which humans can`t do due humans can`t do due to our sizeto our size

Activities in odd Activities in odd enviroments, unable enviroments, unable for humans.for humans.

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Are robots always better?Are robots always better?

Robots may be better for Robots may be better for repetitive, accurate or repetitive, accurate or dangerous tasks butdangerous tasks but

Robots haver not a Robots haver not a thougth of their ownthougth of their own

Robots can not improvise. Robots can not improvise. If there is an unpredicted If there is an unpredicted problem, they won’t be problem, they won’t be able to perform a taskable to perform a task

Robot’s capacity to interact Robot’s capacity to interact with people is limited.with people is limited.

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Parts of a robotParts of a robot

We can consider a We can consider a robot as a control robot as a control system where the system where the actuator is a actuator is a kinematic chain. kinematic chain. Therefore we haveTherefore we have

DetectorsDetectors Computer: controls Computer: controls

the devicethe device Kinematic chain: Kinematic chain:

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Types of robotsTypes of robots

Robots can be Robots can be classified according classified according to many to many parameters:parameters:

Movement Movement Coordinates.Coordinates.

Where they workWhere they work

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Types of robots: Moving Types of robots: Moving coordinatescoordinates

Cartesian robots Cartesian robots are those which are those which move according to move according to x-y-z coordinatesx-y-z coordinates

Polar or cylindrical Polar or cylindrical robots can describe robots can describe a circular a circular movement in a movement in a plane as well as a plane as well as a linear one which is linear one which is perpendicular to itperpendicular to it

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AndroidsAndroids An android is a robot An android is a robot

with a human with a human resemblance. They try resemblance. They try to imitate human to imitate human movements and movements and actions. actions.

They can consist of a They can consist of a human like part, such human like part, such as an arm or either a as an arm or either a whole human body.whole human body.

Androids are still Androids are still under developementunder developement

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