Hide-n-seek Robot

Ivan See & Karen Tsang

Presentation Date: 9/18/03

Objectives

A robot that recognize and search for tangible objects and carries the correct object back to the original location

Involves servomotor control, DC motor control, image processing, PDA programming, and ultrasonic sensor utilization

Overview

1. User shows targeted object in front of the robot’s camera

2. Robot takes a picture of the object and stores it in its memory

3. User hides the object within ultrasonic-reachable area and press the “Go” button on the robot

Overview (cont.)

4. Robot starts searching for the object by using its ultrasonic sensor

5. Robot approaches sensed object and recognize if it’s the correct object by using its camera

6. Robot grabs on the object and brings it back to the start position

Parts Arrangement

Block Diagram

User Interface

User interacts with the Palm which will be mounted at the back of the robot

“OK” button will be shown on the screen of the Palm for starting the initial photo taking procedure

“Go” button will be shown on the screen for starting the searching procedure

“Reset” button will be shown on the screen for restarting all the procedures

Specification

1.5m radius ultrasonic effective area 320 x 240 image processing resolution Travels approximately 1ft/sec Hold targeted object in arms up to 0.5lb Final returning position error < 1ft2

Specification

Only objects in symmetrical shapes will be used Only floor in plain color will be used for testing to

avoid image background confusion (No patterns are allowed on the carpet)

Sufficient light source to avoid too much shadow area appear under the target object

No obstacles allowed in operating area

Ultrasonic Range Finder SRF08

Voltage 5V only

Current 15 mA typical,

3 mA standby

Frequency 40 KHz

Range 3 cm (~1") to 6 m (~20 ft.)

Timing Fully time echo, freeing host controller of task

Echo Multiple echo for velocity determination

Connection Standard IIC bus

Units Range reported in uS, mm, or inches

By Devantech

Uses sonar to detect objects

Detects up to 16 returning echoes

Built-in light sensor

Object Location Algorithm

Image Processing Algorithm

Image Processing Algorithm

Compare pixels one by one Pixel is valid if color value is within

tolerance ranges Validity of an entire image is considered

by a certain percentage of valid pixels

The foot

DC Motor Module from the “Rumble Robots Invasion”

Motor A drives two wheels on the right, while Motor B drives two wheel on the left

Forward, backward, turn left or right

Make 0 degree radius turns Driven by SN754410 Motor

Controller IC from Texas Instruments

The foot

Test Plan

Targeted objects such as apple, orange, and lemon will be used to check if the robot will be able to distinguish between objects in different color

Accurately locate itself in front of the targeted object after searching

Make sure target object is hold in arms while moving

Return to original position with in 1ft2 error

Work Completed

Acquired all hardware components Downloaded Palm emulation software for Palm

software development Acquired reference books for programming Palm

in C Dissembled and investigated “Rumble Robots

Invasion” from Toys R Us Acquired DC Motor wheel module from “Rumble

Robots Invasion”

Work to be done

Assemble arms with servos and optical sensor (Ivan/Karen)

Build DC motor controller circuit with motor controller chip and PAL chip (Ivan)

Install Palm and HC12 on plexiglass rack on the robot (Ivan/Karen)

Investigate SRF08 ultrasonic sensor and its IIC interface (Karen)

HC12 code write up (Karen) Palm code write up (Ivan) Investigate SD camera interface with Palm (Ivan)

System Cost

Palm m130 $130

SRF08 Ultrasonic sensor $55

Motorola HC12 $160 (provided)

Servomotors x 4 $60 (provided)

Motor controller IC SN754410 $5

Palm serial cable $15

Veo SD Camera for Palm $60

Rumble Robots Invasion $15

Plexiglass for base $2

Aluminum Bar for arms $3

Screws and other mountings $2

Optical Sensor x 2 $5 (from IDE class)

Batteries AA X 4 $3

Total $290

Questions?Comments?

Suggestions?