Lego robotics

Lego Robotics Workshop

Team [email protected] Mehran UET, Jamshoro

19-20, Sept 2016Supervisors:Dr. Imtiaz Hussain KalwarEngr. Kamran KaziEngr. Aamir Ali Patoliwww.facebook.com/erevmuet/

Schedule--Today Day-1• Lecture– 10am to 12am• Construction of Robot—12pm to 2pm• Lunch—2pm to 3pm• Construction Resume—3pm to 5pm

Contents• What is Robotics?• Introduction to Lego Robotics• Lego Mindstorms EV3—3rd Generation evolution Intelligent Brick Motors Sensors• Construction of Robot• Programming• Execution of task

What is Robotics?• It is the branch of Mechanical, Electrical/Electronic and Computer

system engineering that deals with design, construction and computer system for their control, sensory feedback and information processing• Mechanical Engineers are concern with design and construction• IT Engineers are concern with control, communication and processing

What is Robot?• Robot is a controllable/programmable mechanical machine.• It can interface with humans and environment• First robot was invented by “George Devol”

Industrial Robots--Gripper

Defence Robots

Contents of Robotics• Servo Motors • Gears• Sensors • Relation of Torque and Speed

Servo Motors• Servo Motor: It is a simple DC motor with some circuitry.• It contain DC Motor Gears Potentiometer Feedback Control System• Servo Motor is used for controlled movement.• It is used when we need specified movement. Like two rotation,

rotation for 30 sec or rotation for 90degrees

Mechanism of Servo Motor

Servo Motor—Internal components

Gear• It is used to transfer

motion.• It is used to vary

Torque and speed.• Used to change

direction of rotating element

How Motion is transferred?

Relation Between Torque and Speed

Torque: It tells us how much load can be drived by rotating machine The first gear of vehicle has more torque than speed. Due to this, you

can drive more load but at low speed. Speed: It is angular velocity of a motor.

Lego Robotics

LEGO?

LEGO Group• Lego Group has been designing different robotic kits for education

and competitive purpose

Lego Mindstorms EV3• This is 3rd Generation Lego Robotic kit.• It comes with two different package i.e. different package contain

different assortment of material1) Retail Set 313132) Education Core set 45544

Content• Intelligent Brick• Motors Large Motors Medium Motors• IR (Infrared) sensor• Remote IR Beacon• Ultrasonic sensor• Color sensor• Touch sensor

Intelligent Brick

Intelligent Brick• Serve as control and power section for robot• SpecificationARM9 Processor Flash memory 16MBRam 64MBSupport up to four sensors and four motors USB 2.0 communication to host PC– up to 480Mbit/secSupport Micro SD card up to 32GBConnectors RJ12Power: 6 AA Batteries—1.5x6=9VoltWireless connection via Bluetooth and Wi-Fi

Motors--Large• High Torque• Less Speed• Used to move robot

like tires in cars• Running Speed: 160-

170rpm• Running Torque:

20Ncm

Motors--Medium• Less Torque• High Speed• Used to move small

parts of robot. Like Arm, lift, gun etc• Running Speed: 240-

250rpm• Running Torque: 8Ncm

Large Motor Medium Motor

More Powerful Less Powerful

Slower Faster

Sensor--Ultrasonic• It works on the principle

of reflected sound waves• Used to measure

distance• One ultrasonic sensor can

detect other ultrasonic sensor operating nearby• Range: 3-250cm with +/-

1cm

How it works?• Ultrasonic sensor emits sound waves. These sound waves reflect back

if there is an object in front of sensor. Ultrasonic detects these reflected sound waves and measures the time interval between transmitting and receiving the sound waves. By using the measured time interval it estimates distance between sensor and object

How it works?

Sensor—Infrared(IR)• It works on the principle of

reflected Light waves• Detects infrared light reflected

from object or sent from IR remote/beacon

• Use to measure distance or proximity

• It detects the reflected light and estimate the distance between sensor and object up to 70cm(Proximity Mode) depending upon the shape and size of object.

How Infrared sensor works

Ultrasonic and Infrared work on the same principle of Radar and Sonar• Radar produce radio waves to detect object—Used in defense mechanism• Sonar produce sound waves to detect object– Used in Submarines

Ultrasonic Vs Infrared… Which one is

better?Infrared Sensor can not work in dark environment

while Ultrasonic can.Whereas Ultrasonic is not very good in defining edges

of area

Drawback of Infrared sensor

Ultrasonic and Bat…

Sensor--Color• It is used to detect seven

different colors, reflected light intensity and ambient light intensity

• Ambient Light tells us how bright or dark the environment is.

• Cell phone has built-in ambient light sensors. Due to this cell phone adjusts its brightness by itself

How color sensor works?

Do colors exist?

What is Color?• Confused? Light, an electromagnetic wave, can come in different

wavelengths. These wavelengths enter your eye and the energy gets absorbed by cells on the back of your eye. This light energy then gets converted into chemical energy, gets processed by a few hundred million specialized neurons, and after a few fractions of a second magically your brain says wavelength 450nm is blue and wavelength 520nm is green.

How Color sensor works?• The color/light sensor shines the white light on object and detects the

reflected colored light.• The color sensor shines three colors (RGB—Red, Green and Blue) on object,

measure the reflected color intensity and recognize the actual color of object. If we shine RGB on red object, the red color becomes more brighter and

reflect back with more intensity while the green and blue get absorbed by object—Hence the sensor can detect red color

Above principle is same for green and blue color• It can also record the intensity(brightness) of color/light.• It has photodiode, which convert the light into current.

How human eye detect color?

Sensor--Touch• It is like a button.• It sense Pressed,

Released and Bumped• Bumped=Pressed and

Released

Sensor--Gyro• It sense the rotational

motion on one axis or rate of rotational motion(degrees per second)—Angular Velocity

• Measures how fast and how far your robot is turning

Application of Gyro Sensor• Gyro sensor is used in airplane, jet plane etc• Your cellphone has built-in Gyro sensor Screen rotation is sensed by Gyro sensor

Infrared(IR) Beacon/Remote

• Used to control robot• Can be used in 2 modes• 1. Beacon ( IR sensor follows it)• 2. Remote (sends commands to brick)

Accessories Education Edition Home edition

Rechargeable Battery Yes No

Intelligent Brick 1 1

IR Beacon (Infrared Remote Control) 0 1

Infrared Sensor 0 1

Ultrasonic Sensor 1 0

Touch Sensor 2 1

Color Sensor 1 1

Gyro Sensor 1 0

Large Motor 2 2

Middle Motor 1 1

Construction of Robot Lets Start

How to construct your Robot?

Just join/connect different components of Robot according to your design/task

Here are the Components