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?