Download Drawing the Maze

G.U.N.D.A.M.
GROUND UTILITY NETWORK DECIPHERING
AUTOMATED MACHINE
GROUP 10
BLAKE SIMONINI
DIDIER LESSAGE
GABRIEL RODRIGUEZ
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 sides
 One ultrasonic sensors for the front
 One MSP430 microcontrollers
 RC Car Base
 Two XBee Modules
Failed Design
DIDIER LESSAGE
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 sensors
 Two on sides to detect
angles

Auto correction
 RC Car Base
 Two motors control front
and back
 Issue?


Blown out sensor during
construction
Turning proved difficult
without isolation
GUNDAM 3.0/Controller
BLAKE SIMONINI
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 detection
 Calibration of the motors
 Directly controls whether the robot is turning left,
turning right, or going forward
 Interfaces with the Ultrasonic sensors in order to
solve a particular kind of maze (which will be
explained later)
Motor Microcontroller
H-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 current
 D 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 algorithm
 Specifications:
 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: 4.0-5.25V
 Baud rate up to 921.6kbps
 On chip voltage regulator
 Virtual 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 5.5V
 Operating Current 33 to 50mA
 Measures 4cm to 30cm
 Analog 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 3m
 Operating Voltage 5V
 Current consumption 20mA
 Ultrasonic Frequency 40kHz
 Communication
 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
Research
Design
Hardware
Completed
Remaining
Software
Testing
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20
40
60
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120
QUESTIONS?