Topic 7 - Control

Features of Autonomous Agents

Autonomy

Reactive Behavior

Sociality

Persistence

Types of sensors may include

Temperature

Motion/proximity

Vibration

Heat detectors

Microwave beams

Infrared beams (motion)

Pressure

Light

Machine vision

Tactile 

Touch

Transducer

A device that converts variations in a physical quantity, such as pressure or brightness, into an electrical signal, or vice versa.

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Output transducer: converts electrical signal to physical energy

Input transducer: converts physical energy into electrical signal

Analog Data (AD) converter

takes the electrical signal and converts the input into a whole number value

Actuators

a part of the system that 'moves' such as motors in the wheels or engines that make the arms go back and forth.

Microprocessor

an integrated circuit that contains all the functions of a central processing unit of a computer.

Transducer examples

a microphone (input device) converts sound waves into electrical signals for the amplifier to amplify 

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a loudspeaker (output device) converts these electrical signals back into sound waves 

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interrupt

A signal sent to the processor indicating an event that needs the processor's immediate attention. It will cause a current process to stop.

Embedded System

A computer system with a dedicated function within a larger electrical or mechanical system.

feedback system

By routing output values as input values, a system can be controlled through modifications at specific times. This keeps performance as optimal.

Feedback system steps

1\. Input transducer measures desired value

2\. Analog signal is converted to digital signal

3\. Microprocessor receives digital signal

4\. The measurement is compared to the desired value range

5\. Adjustments are done as necessary through the output transducer until system is back to normal

6\. Repeat the process while system is functional

Centrally controlled system

Involves a central computer that controls all actuators and sensors. 

Polling

The continuous checking of all input devices by the processor to check the state of the system. 

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If input device does not respond there is no reply and system can act accordingly.

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If input device reads signal outside of the desired range, system will act accordingly. 

Sensor

A device that responds to a physical stimulus (as heat, light, sound, pressure, magnetism, or a particular motion) and transmits a resulting impulse (as for measurement or operating a control).

GPS

Global Positioning System

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1\. GPS receiver receives information (time of transmission and coordinates) from 3 satellites

2\. Difference between time of transmission and time of reception is used to calculate distance

3\. Trilateration is used to determine exact position 

Advantages of GPS

Accurate traffic information

Fast

Can be used by many devices at once

Disadvantages of GPS

Reliable positions is hard when obstacles are present

Privacy concerns exist

Analog data

Data with values that change continuously, or smoothly, over time. Some examples of analog data include music, colors of a painting, or position of a sprinter during a race.

Distributed Systems

systems in which application processing is distributed across multiple computing devices, as opposed to one central location.