Concept Design Review
THE DUKES OF HAZARDCAMILLE LEGAULT, NEIL KENNEDY, OMAR ROJAS,
FERNANDO QUIJANO, AND JIMMY BUFFI
April 24, 2008
The Dukes of Hazard
Bumper System
Rotating Sensor Arm System
Electronic Components Box
R/C Car Chassis
Autonomous Control (GPS)
Seek Hazardous Material Locations
Quickly Search, Find and Return
Avoid Obstacles
Markets: Civil Service (Meth Labs)Military (Minesweeping)
Commercial (Pest Control)
Key Design Requirements
Accuracy within 1 m
Able to operate on concrete and grass
Visual display of results
Reach and evaluate target within 2 minutes
Weigh 15 pounds or less
Avoid obstacles 3” or higher
Proof-of-Concept prototype is a GPS-guided vehicle that locates and identifies an IR transmitter
Final Concept
Tracks vs. Wheels Cost Simplicity
Obstacle Avoidance ‘Seeing’ the Target Chassis Decision…
Buy vs. Build
Cost True Robot chassis = $$$$ or too small Building a chassis ~ $240 Buying Traxxas Stampede = $196.10
Most Valuable Asset – TIME Main challenges Coding Wiring
Organization
I. Vehicle Feature DesignA. Platform & Enclosure
B. Sweeping Arm & Sensors
C. Bumper
D. Suspension
II. Wiring & Circuitry
III. Programming
IV. Prototype Performance & Feasibility
I - Vehicle Design
Platform and Enclosure
Improvements and/or Alternatives: Permanent platform Compartmentalize circuitry Weatherproofing
Sensor Arm
Dimensions: 17”x 2”x 3/8”
Material: 3/8” Gray PVC Features:
Shelled out Sensor
slots
Sensor Arm
Servo Selection
Signaling
Hazardous: Red lights
Non-Hazardous: Green lights
Signaling
Improvements and/or Alternatives Audio signaling
Speaker Siren
Sensor Placement
Detect transmitter within a foot or less away Rotating arm Effective height and angle for sensor
Sensor/Transmitter System
Maximum range of sensor/transmitter system ~50 feet
Transmitter: ~9° lobe Sensor: ~180° range of view
Experimental Results
Sensor Holder Design
30°
Sensor Arm Mechanism
Improvements and/or Alternatives: Weatherproofing of sensors More supports for arm at rotation point Stepper Motor Height adjustable
Bumper System
Detect and avoid obstacles higher than 3”
Absorb impact Appropriate
spring
Bumper System
Bumper System
Bumper System
Improvements and/or Alternatives: Permanently attach bumper Softer springs Ultrasonic range-finder
Suspension System
Suitable shocks to: Handle various terrains Maintain desired ground clearance: ~3”
Suspension System
II - Electronics
Improvements
Multiple Power Sources Concept Phase - Make into single source Stabilize voltage during signaling
Simplify interfacing with microcontroller 5 V circuits, or voltage regulators
Electronic noise filters Internal Circuitry Protection
III - Programming the Vehicle
MAJOR ISSUES Interfacing with the
chassis Interfacing with the GPS Creating a search
algorithm Avoiding obstacles
PROGRAM FLOW1. Wait for GPS to fix.
2. Store coordinates of transmitter.
3. Move vehicle to new location.
4. Begin Search Algorithm.
5. Stop if transmitter is found or perform avoidance routine if obstacle is encountered.
User Interface1. “Waiting” Mode
2. Store coordinates
3. “Preparing for movement” mode
4. Activate the car and begin search
5. Car will display “Hazardous Material Found”
Is x1 > x2?
Is y1 > y2?Is y1 > y2?
Is x1 > xold or y1 > yold?
Is x1 < xold or y1 > yold?
Is x1 > xold or y1 < yold?
Is x1 < xold or y1 < yold?
Turn.Go
straight.Turn. Turn. Turn.Go
straight.
Go straight.
Go straight.
Go forward and straight.
YES NO
NO
NONONONO
NOYES
YES YES YESYES
YES
Is sensor activated?Stop. Keep Going.
X1 = current car
X2 = transmitter
Xold = car 2 sec. ago
Search Algorithm
Programming Areas to Improve
More precise pulse width modulation. More efficient search algorithm.
Use a digital compass. More speed variation.
Streamline programming with functions. Reverse the search algorithm to make the car
return to the starting point after the “hazardous material” is found.
Storing multiple locations
IV - Proof of Concept Demonstration
IV - Proof of Concept Demonstration
IV - Performance Evaluation
Score based on the Prototype Requirements
83/90
IV - Performance Requirements
Hazard Sensor Accuracy (10/10) Sensor activated consistently within 1 foot of
transmitter Vehicle Accuracy (15/15)
Reached locations within 1 meter of transmitter
Obstacle Avoidance (15/15) Successfully avoids obstacles
Time to reach transmitter (10/10) Successfully reaches and evaluates target within 1
minute
Performance Requirements
Vehicle Weight (10/10) Final Prototype Weight: 10.976 lbs
Audio/Visuals (6/10) No audio signal Visual signal detectable within 20-60 yards depending
on illumination. Incline Movement (7/10)
Able to move up a 30o incline Cost (10/10)
Proof of concept cost: ~ $375.00
IV - Feasibility
Main objectives: Vehicle and Sensor Accuracy Obstacle Avoidance
Future Showstoppers Maneuvering through extreme terrain Work indoors Weather conditions
Additional Information
www.nd.edu/~me463a18
QUESTIONS?
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