robotic sensors ppt

7/25/2019 Robotic Sensors PPT

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A Seminar OnA Seminar OnRobotic SensorsRobotic Sensors

By: MANOHAR SINGHBy: MANOHAR SINGH12EI1912EI19


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Contents

What is a Robot?

What are Sensors?

Why do Robots Need Sensors?

Classification of Sensors

What Sensors are Out There?

What can They do?Conclusions

References


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What makes a machine a Robot?What makes a machine a Robot?

where should I dig?

where

is thetruck?

Sensing Planning Acting

informationabout theenvironment

actionon the

environment


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What Is A Robot???

RobotsMachines with sensing, intelligence andmobility

To be qualified as a robot, a machine shouldhave the following capabilities:

Sensing and perception: get information

about itself and its surroundingsCarry out different tasks

Re-programmable: can do different things

Function autonomously or interact with

human beings


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Why Use Robots???

Application in 4D environmentsDangerous

Dirty

Dull

Difficult

4A tasksAutomation

Augmentation

Assistance

Autonomous


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Types of Robots

Underwater robotHumanoid robot Aerial robot

Legged robot

ManipulatorWheeled

Mobile Robot

(WMR)


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What is Sensing ?

Collect information about the world.

Sensor - an electrical/mechanical/chemicaldevice thatmaps an environmental attribute

to a quantitative measurement.

Each sensor is based on atransduction

principle-conversion of energy from one form

to another.

Also known astransducers.


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Why To Use Sensors???

Vision outside the RGB spectrumInfrared Camera, see at night

Active vision

Radar and optical (laser) range measurementHearing outside the 20 Hz 20 kHzrange

Ultrasonic range measurement

Chemical analysis beyond taste andsmell

Radiation: a, b, g-rays, neutrons, etc


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Why do robots need sensors?

?

internal information

What is the angle of my arm?


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Where am I?

localization


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Will I hit anything?

obstacle detection


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Provides awareness of surroundings

Whats ahead, around, out there?

Allows interaction with environmentRobot lawn mower can see cut grass

Protection & Self-PreservationSafety, Damage Prevention, Stairwell sensor

Gives the robot capability to goal-seekFind colorful objects, seek goals

Makes robots interesting

Why Do Robots Need Sensors?


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13 Solar Cell

Digital Infrared Ranging

Compass

Touch Switch

Pressure Switch

Limit Switch

agnetic Reed Switch

agnetic Sensor

iniature Polaroid Sensor

Polaroid Sensor !oard

Pie"o #ltrasonic Transducers

P$roelectric Detector

Th$ristor

%as Sensor

%ieger&uller

Radiation Sensor

Pie"o !end Sensor

Resisti'e !end Sensors

echanical Tilt Sensors

Pendulum Resisti'e

Tilt Sensors

CDS Cell

Resisti'e Light Sensor

(all )ffect

agnetic *ield

Sensors

Compass

IRDA Transcei'er

IR Amplifier Sensor

IR odulator

Recei'erLite&+n IR

Remote Recei'er

Radio Shac,

Remote Recei'er

IR Sensor w-lens

%$roAccelerometer

IR Reflection

Sensor

IR Pin

Diode

#. Detector

etal Detector


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ClassificationofSensors

Proprioception (Internal state) v.s.Exteroceptive (external state)measure values internally to the system (robot),e.g. battery level, wheel position, joint angle, etc,

observation of environments, objects

Active v.s. Passiveemitting energy into the environment, e.g.,radar, sonar

passively receive energy to make observation,e.g., camera

Contact v.s. non-contactVisual v.s. non-visualvision-based sensing, image processing, videocamera


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Tactile Sensors

There are many different technologies e.g.contact closure, magnetic, piezoelectric, etc. For mobile robots these can be classified as

tactile feelers (antennae) tactile bumpers Pressure-sensitive rubber with scanning array


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WhiskersPiano wire suspended through conductivehoop

Deflection causes contact with hoop

Springy wire that touches studs when deflectedReaches beyond robot a few inchesSimple, cheap, binary output

Bumpers & GuardsImpact/Collision sensor, sensespressure/contact

Microswitches & wires or framework that moves

Simple, cheap, binary output, easy to read

Tactile Sensors(Feelers)


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Feelers - Whiskers


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Feelers - Bumpers & Guards


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Bend Sensors

Resistance = 10k to 35kAs the strip is bent, resistanceincreases

PotentiometersCan be used as position sensors forsliding mechanisms or rotating shafts Easy to find, easy to mount

Light Sensor (Photocell)Good for detectingdirection/presence of light Non-linear resistance

Slow response to light changes

Resistive Sensors

Resistive end !ensor

"hoto#ell

"otentiometer

R is small when brightl$

illuminated


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!ensor

Measure bend of ajoint

WallFollowing/Collision

Detection

Weight Sensor

!ensors

!ensor

Applications


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Sensors IR

Active (emitting)Oscillator generates IR reflections off objectsFiltered receiver looks for reflectionsPulses may be encoded for better discrimination

Typically frequencies around 40KHzDoesnt work well with dark, flat colored objects

Passive (sensor only)

Pyro-electric (heat sensor)Look for IR emissions from people & animalsUsed in security systems & motion detectors


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Infrared - Active

Works at about 15degrees away from therobot


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Sensors Ultrasonic

ActiveEmit pulses & listen for echosTimes round trip sound travel (~1ft/mS)Reaches far fairly beyond robot (inches to 30-50)

Relatively simple, not cheap, analog outputDirectional; not everything reflects sound well

Passive (listens only)

Sensor listens for ultrasonic sounds

Electronics may translate frequency ormodulation

Software may perform signal analysis (FFTs, etc.)


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Ultrasonic - Active


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Sensors Ultrasonic (cont.)

Passive - Beacons & SensorsBeacons listen: RF command to broadcast

Send light & sound pulsesRobot looks & listens for each beaconLight pulse starts timer, sound pulse stops it

Robot knows location of each beaconCompass on robot provides its orientation

Robot computes distance, measures bearing

Robot can then compute its location

(Speed of Light=1 ft/nS, Speed ofSound=1ft/mS)


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Ultrasonic - Passive

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"ulse

Robot

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R& Re#eiver

'R mitter

Ultrasoni#

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Conclusion

Sensors provide a way of simulating aliveness

Sensors give robots environmental awareness

Sensors provide of means of human protection

Sensors help robot preserve itself

Sensors enable goal seeking

Sensors enable closed-loop interaction

Sensors make robots interestingSensors can make programming challenging


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References

* www+a#roname+#om ,a##essed on -./-0/1.

* www+google+#o+in ,a##essed on -./-0/1.

* www+l$n2motion+#om ,a##essed on -./-0/1.* www+drrobot+#om,a##essed on -./-0/1.

* www+robotstoreh+#om/sensor+html,a##essed on

-./-0/1.
http://www.google.co.in/http://www.lynxmotion.com/http://www.drrobot.com/http://www.drrobot.com/http://www.robotstorehk.com/sensor.htmlhttp://www.robotstorehk.com/sensor.htmlhttp://www.drrobot.com/http://www.drrobot.com/http://www.lynxmotion.com/http://www.google.co.in/


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