CogitoBot IGVC Autonomous Vehicle From Lawrence Technological University MayJune 2003

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CogitoBot IGVC Autonomous Vehicle From Lawrence
Technological UniversityMay-June 2003

• Team Name LTU Thinkers
• By Andrey Shvartsman
• Santosh Nair
• Li Ping Chen
• Date 05/31/2003

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Hardware Design and Implementation
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Robot Body

• The robot body was designed and built from
  off-the-shelf components.
• The main body was constructed from particle board
  0.75 inches in thickness.
• The upper body was constructed from particle
  board 0.25 inches in thickness.

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Drive Train and Gearing

• Front-wheel drive
• 8-inch lawn mower wheels
• 51 Teeth on each wheel
• Stationary axle
• Wheels rotate freely on the axis in both
  directions
• Coupled to 13 tooth gear
• 41 gear ratio, higher torque
• Gear mounted directly on motor shaft

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Motors and Motor Control

• 12V DC wormgear bi-directional high-torque motors
  
• Motor Shaft Rotates at 120 RPMs
• Controlled by a dual channel 30 Amp driver board
• Commands sent through laptop parallel port

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Electrical System

• 2 IR Distance sensors
• 1 Sonar sensor
• 2 LogiTech Cameras
• HandyBoard 68HC11 Microcontroller
• Interface between sensors and laptop

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High-Level Software Architecture
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Vision Processing

• Image frame from 2 cameras are concatenated to
  form a single frame that is much wider.
• This image frame is then formatted to a grid of
  4X12.
• Each cell is processed to check for lane and
  obstacle presence.
• Information from all the cells are combined to
  know the position of Left and Right lanes and the
  Obstacle Width and position.
• These information are used as inputs to the Fuzzy
  Inference System

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Sample Image Frame without Obstacle
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Sample Image Frame without Obstacle - II
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Sample Image Frame with Obstacle
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Fuzzy Inference System
Speed for Motor R
Lane center position
Fuzzy Inference System FIS
Obstacle center position
Speed for Motor L
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FIS Rules
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Membership functions - I
Far left
middle
right
Far right
left
-6 -2.5 3 6.5 10 14 18
7 6 5 6 7
Membership function for lane center position
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Membership functions - II
middle
right
No obstacle
left
No obstacle
-1 0 2.5 6 9.5 12 13
2 5 4 5 2
Membership function of obstacle edge position
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Questions?
Thanks for listening