prabhat (73)robotics

8/8/2019 Prabhat (73)Robotics..

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Robotics

-Prabhat Chandra Bajpai


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Different Types of Robots

1. Ro b o t Arms (Fixed Ro b o ts)2 . Mo bile Ro b o ts

Hu man o id Ro b o tsLegged Ro b o ts

Wheel Ro b o ts3 wheels

2 Driver wheels, 1 Caster 1 Driver wheel, 2 Casters

4 wheelsCasters make diverse pr o blems in the c o ntr o l of the r o b o t


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Wh eel Robot Main Components

M ain C o mp o nentsM echanics

WheelsDriver Mo to r (s)P o wer Transmissi o n System

Electr o nicsCo ntr o ller B o ard

Needingf eedback

f r

om envir

onment

Sens o rsWe are now discussing some of the above

topics


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Different Types of Motors

DC Mo to rs Yo u can simply c o ntr o l it

AC Mo to rsIts di ff ic u lt t o be c o ntr o lled b u t it canbe u sed in high p o wer applicati o ns

Serv o Mo to rs Yo u have c o mplete c o ntr o l o n the sha f t

angle


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Different Types of Feed Back Sens o rs

IR Sens o rsPress u re Sens o rsLight Sens o rs

Temperat u re Sens o rsEnc o der


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Wh at is Encoder


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Wh y do we use Power Transmission Systems?

1.T

ored

uce Ang

ular Vel

ocity2 . To increase T o rq u e

Diff erent Transmissi o n SystemsG ear

H ard man u f act u ringand adj u stment

P u lley

S o [ => T


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GearG ears are u sed t o change the speed andfo rce of the m o to r . Yo u can u se gears t o:

1. Speed u p o r sl o w d o wn y o u r r o b o t .

2 . M ake y o u r r o b o t str o nger o r weaker .

There are many di ff erent types of gearsSp u r G ear Bevel G ear Wo rm G ear R ack & Pini o n


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GearSp u r gears are wheels with teeth


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GearBevel gears mesh at right angles, s o

they change the directi o n of r o tati o n .


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GearWo rm gears l oo k like screws . They have

many special pr o perties .


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GearR ack & pini o n gears t u rn r o tati o nal m o tio n

int o straight-line m o tio n .


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Where does all this torque come from?

Consider a pair of gears that are meshed together.

FX

T he moment arm is the radius of the gear.Remember: X = F x r

r

A torque

on thisaxle...

producesa force at the tooth.


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F

Xr

T he force from the small gear s tooth pushes against

the large gear s tooth. T his creates an equal (and opposite)force in the large gear. T his is Newton s 3rd Law.

andproduces alarger torqueon this axle.

T he force acts through this larger moment arm ...


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F1 = -F 2

X

r 2

X

r 1

A nalyzing the forces... X1 = F1 x r 1 X2 = F2 x r 2

F1 = X1 / r 1F2 = X2 / r 2

F1 = - F 2

X1 / r 1 = -X2 / r 2

X2 / X1 = r 2 / r 1

T he ratio of torques is the ratio of the gear radii.T his is the g ear ratio!


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GearThe gear ratio of this gear box is 75 to 1

T hat meansthe last axlerotates 75

times slowerthanthe first axle.It also meansthe last axlehas 75 timesthe torque asthe first axle.


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T ry this experiment.

Have one person turnthis wheel.

A nd have another persontry to hold on to this wheel.


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Gears can increase the torque (and force) that they exert

on something.T

his is known as mechanical advanta g e .

BUT , it comes at a price. Do you know what it is?

torque increases


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Belt Drives

U ses f ricti o n t o transmit p o wer

2

1

C

[2 [ 1

D2D1

2

1

[

[!VR

Velocity Ratio:

D 1. [ D2 .[


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Shaft Size for DR,can use NEMA frame

Belt Drive Basics

Motor Nameplate

Center Distance(center shaft to center shaft)

T ake-up/Installation Allowance

SizeSize

DR DN


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Belt Drive Basics

R N

R N Speed Speed--UpUp

Speed Speed--Down Down 1010

1750 rpm1750 rpm

1010 44

44

700 rpm700 rpm

4375 rpm4375 rpm

Ratio always greater than 1

Sp eed Ratio = 2.5


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How to assemble our RobotH ere is o u r package


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How to assemble our Robot

1 2

3


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How to assemble our RobotBo tt o m view of the r o b o t


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How to assemble our RobotSens o r b o ard assembly


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Th ank You!

.

prabhat (73)robotics

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