GROUND UTILITY NETWORK DECIPHERING AUTOMATED MACHINE

GROUP 10

BLAKE SIMONINIDIDIER LESSAGE

GABRIEL RODRIGUEZ

G.U.N.D.A.M.

What is it?

A robot whose primary function is solving mazes of varying types using the wall follower method of maze solving

Maze will be custom built with a layout capable of being changed to any type depending on the user’s specifications

Motivation

Provide a system for exploring locations others cannot.

One of the main advantages of using a robot to traverse unexplored territory becomes evident in places where humans can’t go due to size or potential hazards, such a cave.

Parts Being Used

Two ultrasonic sensors for the sidesOne ultrasonic sensors for the frontOne MSP430 microcontrollersRC Car BaseTwo XBee Modules

DIDIER LESSAGE

Failed Design

GUNDAM 1.0

Chipped gears Solutions?

Attach plastic base to front for reduced friction after lost front wheels

Attach a ball to base to allow for smoother movement

Turns now made virtually impossible on carpeted surface

Blown out motors Solutions?

New motors, resulting in changed values for the software

Low weight support Solutions?

New Chassis

GUNDAM 2.0

Four ultrasonic sensorsTwo on sides to detect

angles Auto correction

RC Car BaseTwo motors control

front and backIssue?

Blown out sensor during construction

Turning proved difficult without isolation

BLAKE SIMONINI

GUNDAM 3.0/Controller

GUNDAM 3.0

• Added a connector to interface with the MSP430 development board without having to remove the Processor

• Cleaned up the wires and used colored wires for what each line was

• Clamps to keep everything organized

• Wires don’t interfere with sensors now

Motor Microcontroller

Deals with collision detectionCalibration of the motorsDirectly controls whether the robot is turning

left, turning right, or going forwardInterfaces with the Ultrasonic sensors in

order to solve a particular kind of maze (which will be explained later)

Motor MicrocontrollerH-Bridge

Motor Microcontroller

Input 1 Input 2 Front Motor Output (Steers left and right)

Low Low Steer Straight

High Low Turn Wheels Left

Low High Turn Wheels Right

High High Steer Straight – Motor Off

Input 1 Input 2 Back Motor Output (Drives forward and backward)

Low Low Nothing Happens

High High Nothing Happens

Low High Drive forward

High Low Drive backward

Motor Microcontroller

Battery Options

AA Batteries Wouldn’t supply enough current and when they got

hot they would supply less currentD Batteries

Supplied enough current, but are too heavy.Lithium Polymer

Supplies enough current and is lightweight

Wireless Subsystem

- ROBOT MODULE

- Mounted on the robot to send and receive information from the MSP430

- COMPUTER MODULE

- Connected through a computer’s USB port to send and receive data from the Java GUI.

Robot Module

PCB layout XBee Wireless Transceiver Module

Interface with MSP430 through UART

Computer Module

PCB layout XBee Wireless Transceiver Module

CP2101 UART to USB Interface XBee through UART to PC USB

XBee Wireless Module

Encrypt data in AES-128 algorithmSpecifications:

3.3V operating voltage 2.4GHz operating frequency Adjustable Power output 1.25-2mW Range 120m Data rate: 250kbps UART interface

UART to USB Bridge (CP2102)

USB Bus powered powered: 4.0-5.25VBaud rate up to 921.6kbpsOn chip voltage regulatorVirtual COM port for GUI

Range Finder Subsystem

- INFRARED SENSORS

• The initial plan was to mount one on the left side and another on the right side of the robot.

-ULTRASONIC SENSORS

• The initial plan was to mount one sensor on the front and another on the back of the robot.

Infrared Range Finder (GP2D120)

Operating Voltage 4.5V to 5.5VOperating Current 33 to 50mAMeasures 4cm to 30cmAnalog output

Output Voltage (V) vs. Reflected distance (cm)

IR Sensor Malfunction

During the construction of GUNDAM 2.o, an IR sensor was damaged

Solution? Two ultrasonic sensors were then used to replace the

IR sensors that were originally planned to be used to auto correct and detect paths

GUNDAM 3.0 modified this even further by only using one sensor on each side

Final Ultrasonic Layout

One ultrasonic sensor mounted on the left, the other on the right Used to auto correct the GUNDAM while traveling

straight Used to detect paths

One ultrasonic sensor in front Used to detect obstacles Used to detect forward paths

Ultrasonic Range Finder

Measures 2cm to 3mOperating Voltage 5VCurrent consumption 20mAUltrasonic Frequency 40kHzCommunication

Positive TTL Pulse

Physical Maze

Plastic, Wood, Metal, Rubber, and Paper reflect ultrasonic waves.

Things to consider: Cost : Metal > Plastic > Wood Ease of Manufacturing: Metal > Plastic > Wood

Wooden planks, each one foot in length

Maze Layout

Maze Solving (Path Finding) Algorithms

Wall Follower Simple maze solving solution that involves following

the left side of the maze, including any turns that may follow. Will be the default maze solving method

This solution is only valuable in certain maze situations. If the entrance of the maze happens to lie in the center and not on the outside edge, or if a wall happens to lie on its own with no connections, it will fail

GUNDAM Maze Solving Walkthrough

GUNDAM continues forward until a path is detected on one of its sides. It will try to center itself with the walls while it is moving forward.

If path detected: Check for a left_path(); Check for a front_path(); Check for a right_path();

• When each path is open, we know we have solved the maze.

How Turning is Done

The Ultrasonic Sensors become inaccurate after they are angled at an object past about 45 degrees.

To determine a turn, we use a wall around the robot for the turn and turn the robot until that wall distance is giving very large and inaccurate values from the sensor.

This way we can get an idea of how far we have turned, even though the sensors aren’t that accurate for turning.

Drawback is that we can’t have a full intersection, since not having at least one wall on a turn would break this idea.

Turning has to be three point turns.

How To Perform Proper Turns

Side Feature: Maze Drawing

Draws out maze as GUNDAM solves using the wall follower method

Upon reaching each node, present paths are sent to laptop

The same algorithmic idea on GUNDAM is applied to path to predict next stretch of maze pathways to draw out as the GUNDAM’s next move

Packets may be lost or resent, causing software to not be reliable

Progress

Testing

Software

Hardware

Design

Research

0 20 40 60 80 100 120

CompletedRemaining

QUESTIONS?