Beagle Bot

7/30/2019 Beagle Bot

1/22

Beaglebot

Mobile Image Processing Platform

Robot Platform

Arduino

Obstacle Avoidance

Beagleboard

OpenCV: Image Processing

Ball Detection


2/22

Robot Platform

There are two levels of processing on the Robot.

Lower level sensor reading and motor control doneby Arduino Microcontroller.

Higher level Image processing on Beagleboard (ARMSOC).

Detection of obstacles using sonar sensors.

Perception of surroundings using Computer Vision.


3/22

Robot Platform

Movement provided by DC Motors controlled bymotor driver

Robot has a Differential drive system

Semi circular array of Maxbotix sonars Used for Obstacle Avoidance


4/22

Robot Platform

Multiple levels in Robot

lower level for Microcontroller

Higher level for Microprocessor

and Camera


5/22

Arduino Platform

Open-source Microcontroller platform

Designed upon Atmega Microcontroller Series

Entire Software and Hardware Package

Onboard GPIO and PWM pins

Capable of running DC Motors and Servo Motors Onboard ADC capable of reading sensor readings

Used for lower level functioning of Robot


6/22

Arduino Mega 2560

Operating Voltage 5V

Digital I/O Pins 54 (of which 14 provide PWM output)

Analog Input Pins 16

Flash Memory256 KB of which 8 KB used bybootloader

Clock Speed 16 MHz


7/22

Arduino Platform

Robot can detect obstacles by reading signals fromsonars

Depending on location of Obstacles, the Arduino

takes its decisions and avoids them


8/22

Obstacle Avoidance

Arduino collects analog voltage from each sonar

Computes the distance of Obstacle

Disturbance in sonar readings when robot is in

motion Averaging of over 50 readings to eliminate noise

This way Robot can detect obstacles atleast 90% ofthe cases


9/22

Obstacle Avoidance

The Present Algorithm is not memory based

Computes least value of all sonars and checksthreshold

On Obstacle Detection, computes largest sonarreading

Rotates in that direction and leaves

If all sonar readings are less, rotates back and leaves


10/22

Obstacle Avoidance

Sample of Obstacle Avoidance Code

In this the Robot enters a circle of Obstacles andthen leaves it successfully

Run Video obstacle.avi


11/22

Beagleboard

Beagleboard is an ARM based System on Chip

Texas Instruments OMAP3 Processor

700 MHz Processing Speed

Support for DVI-D Display, Audio Ports, USB Hub Support for Ethernet and Internet Connectivity

Functionality of a full-fledged Desktop

Onboard GPIOs and 16-bit PWM pins Can also be used in controlling Motors and Sensors


12/22

Beagleboard

http://www.beagleboard.org/


13/22

Linux on Beagleboard

Boots Linux from SD Card

Beagleboard widely supported platform

Pre-built binaries for many popular Linux

OS(Debian, Ubuntu, Fedora) These Binaries actually meant for Netbooks

Too power hungry for Beagleboard

Better to build own kernel with light weight packages


14/22


Rootstock is a program which builds custom UbuntuDistribution

Meant for ARM based development boards

Program downloads the kernel and necessarypackages

Compiles the kernel on a host system using cross-compiler

It generates a compressed filesystem which is loadedonto SD Card


15/22


Firstly rootstock needs to be installed in the hostsystem,

sudo apt-get install rootstock

Then the following command needs to be run,sudo rootstock--fqd n om a p --login ubuntu --passw ord

temppwd--im a g es ize 4 G --seed w get,nano,linux-firm w are,w ireless-

tools,usbutils,xfce4,gdm,xubuntu-gdm-theme,xubuntu-

artwork,xserver-xorg-video-omap3,btrfs-tools,devmem2,i2c-

tools,nano,pastebinit,wpasupplicant--d is t m a v erick --serial tty O2 --com ponents "m ain universe m ultiverse"--k er n el-im a ge

h t t p :/ / r c n -e e .n e t / d e b / m a v e r i ck / v 2 . 6 .3 8 . 4 -x 3 / li n u x -i m a g e -

2.6 .38 .4-x3_ 1.0 m a v er ick _ a r m el .de b


16/22


In the previous command Firstly type of board is specified as OMAP3

Then the imagesize is specified to be 4GB

Then all the packages to be installed along with basicfilesystem is given

Finally the link to beagleboard specific kernel is given

The SD Card on Beagleboard has 2 partitions

First partition has initialization scripts Second partition has filesystem


17/22

Programming Environment

Robot can work as a Desktop

for development

Access through Serial Port

Robot can also be logged onRemotely using ssh


18/22

OpenCV: Image Processing Library

The Robot can better perceive its environment usingComputer Vision

OpenCV: Image Processing Library

Open-source package with a lot of support andDocumentation

The Robot can interact with humans and otherrobots using OpenCV


19/22

OpenCV

Image Processing Applications done on Robot

Canny Edge Detection done on the Robot

OpenCV Library also has Video Processing

extensions Algorithms being developed for detection of other

Robots in the Environment


20/22

Ball Detection

The Robot has a ball mounted on top

Ball has multiple leds in it

Depending on the state of Robot, the ball will glow a

color The aim of other Robots is to successively locate all

balls in Environment and to identify the master

Present algorithm uses the cam-shift algorithm


21/22

Ball Detection

The video for ball detection

In this the ball is being successfully detected in thedark

On switching on the Light, there some decrease inAccuracy

Run Video ball.avi

Better algorithms currently being developed


22/22

Resources

Detailed explanation about setting up hardware

Circuit Schematics, Support for Beagleboard

Example Arduino codes and OpenCV Codes

All material uploaded online http://www.themachine.in/
http://www.themachine.in/http://www.themachine.in/

Documents

Beagle Bot