Vision Guided Navigation Andrey Kozitsky Seth Kramer

Overview Introduction to the VGN User Interface Image Recognition System Software Architecture Vehicle Communication Vehicle Control Testing Strategy Difficulties

What is the VGN? The VGN will navigate a vehicle to a destination using only vision as a form of feedback. Birds-eye view of a small area will be processed to practice obstacle avoidance. The VGN will be successful when all destination points have been visited in a user-defined order without any collisions.

Components of the VGN Field Graphical User Interface Web Camera Image Recognition System Pathfinding and Control Vehicle Communication and Control

Field 5’ x 5’ Field Black Background Yellow Boundaries White Obstacles Red/Blue Vehicle

Graphical User Interface

Web Camera Video Input TypeDigital Video Camera Software Type Creative Webcam Live! Ultra Digital video capture speed30 frames per second Digital video capture resolution640 x 480 Picture Capture Quality1.3 MegaPixels OS Required Windows XP, Windows 2000 Video Input Color SupportColor Video Input: Interface TypeUSB 2.0, 1.1 Focus AdjustmentManual Lens Angle76 Degrees

Image Recognition System Web Camera snaps a picture every second IRS is a standalone library that offers the following: –Matrix representation of field with values of: 0-Field 1-Obstacle 2-Red 3-Blue –Vehicle Direction -180° to 180° –Field, Vehicle, and Path checking

Image Recognition System HSL Color Space Hue-Saturation- Luminance Boundaries have high Saturation Obstacles have high luminance Navigable Field has low luminance

Image Recognition System YCbCr Color Space Y is luma component Cb is blue chroma component Cr is red chroma component Red part of tank has high Cr Blue part of tank has high Cb

Image Recognition System

Y axis X axis

Image Recognition System Y axis X axis

Software Architecture The system is organized into four packages –PathFinder (Controller) –Image Recognition System –Vehicle –View (Graphical User Interface) Pathfinder interfaces with the other packages

PathFinder

Vehicle Communication Using SCI Communications and.NET Framework 2.0 –System.IO.Ports.SerialPort 8 Bit OpCodes, 3 Bit instruction and 5 Bit parameter sent to HCS12, returned on completion of instruction. If instruction not returned within 5-10 seconds, controller will send ACK and then prompt user Instruction NameOpCodeParameter RangeComments ACK Acknowledge for Communcations FORWARD001XXXXX0—31Send Vehicle Forward BACKWARD011XXXXX0—31Send Vehicle Backward TURN_LEFT1000XXXX0—12Vehicle rotates counterclockwise TURN_RIGHT1010XXXX0—12Vehicle rotates clockwise RESUME Continue after a STOP STOP Wait for RESUME to be given

Vehicle Control Moving when 0Vdc applied to contact switch Stopped when 5Vdc applied to contact switch

Testing Strategy VGN is a success if it exhibits the following: –Navigate a field of obstacles and reach the appropriate destinations in the order specified –Reach each successive destination in a timely manner –User is notified if the proposed destination is unreachable –Vehicle motion stops and resumes from the GUI –User can easily pick desired locations and view the field

Difficulties IRS is heavily dependent on current lighting levels; this may require a lookup table and restrictions on lighting conditions PathFinder may require extensive implementation and testing time for the determining possible paths in worst-case scenarios Vehicle’s drive system is made of plastic, this may result in purchasing of multiple vehicles

Questions?