Preliminary Design Review

1
Preliminary Design Review

• Automatic Windshield Wiper System

Michael Whitfield Anthony Harris Renaud
Moussounda Eric Williams
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Project Overview

• Automated Windshield Wiper System
• Improve safety by decreasing driver distraction
• Target Automobile Manufacturers/ After-market
  Customers
• Goals
• Detect rainfall on windshield
• Detect intensity of rainfall
• Automatically activate windshield wipers once
  rainfall is detected
• Voice-controlled system activation/deactivation
  (Future)

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3
Project Status

• Online project management
• IR sensor, Humidity sensor, MSP430(Microcontroller
  ) ordered and obtained
• Test apparatus designed
• Impedance sensor designed, built, and tested
• Project budget/hours updated
• Project scope fully defined

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High-Level System Diagram
IR Sensor
Output Signal Conditioning Circuitry
Microcontroller MSP430
Input Signal Conditioning Circuitry
Impedance Sensors
Speech Recognition
Wiper Control System
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IR Sensor

• Model OPB 770T
• Mounted inside windshield behind rear view mirror
• 100 reflectivity No rain
• lt85 means rain or moisture is present

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IR Sensor Integration






IR Sensor
MSP 430 Analog to Digital Converter

• Turn current output into a voltage
• Feed voltage through A to D converter
• Microcontroller takes digital output from A to D
  converter and makes decisions

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Impedance Sensors

• Speed control 2 options
• 1st Schmitt Triggers
• 2nd option MCU A/D comparator

Speed Control
MCU
Water closes circuit
Copper Tape
5V
MCU Comparator
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Microcontroller Control Logic

• 14 I/O pins
• 16-MIPS performance
• 16-bit Sigma Delta Analog-to-Digital converter
• LED display

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Software Block Diagram
POWER ON
SYSTEM FAILURE
EXIT
Auto?
SPEECH?
SPEED CONTROL
SYSTEM CHECK
OK?
WIPER ON
Water?
Water?
IR SENSOR
IMPEDANCE SENSOR
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System Integration
Design System
Sensors
12 V
Electronic Relay
MCU
Existing Automobile System
High
Automobile Wiper System
Low
Wiper Switch
Park
Intermittent
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Test Apparatus
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Test Apparatus (cont.)
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Marketing and Cost
INITIAL ESTIMATE (MID-POINT) ACTUAL (MID-POINT) PROJECT ESTIMATE REVISED PROJECT ESTIMATE (w/Voice Activation)
Team Design Hrs 206 hrs 162 hrs 412 hrs 460hrs
Labor Cost(_at_ 30.00/hr) 6,180 4,860 12,360 13,800 (11 Increase)
Parts Cost (Prototype Design) N/A N/A 239 350
Parts Cost (Manufactured) N/A N/A 140 205
Price N/A N/A 600 800
Profit Margin N/A N/A 16 15.4
Figures based on 500 units sold
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Timeline
Task Completion Date
Test all individual components 11/2
Integration of sensors w/ Microcontroller 11/10
Integration of Microcontroller w/ Motor 11/18
Construct Test Apparatus 11/21
Program Microcontroller 11/26
Project Integration 12/3
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Problems

• Interfacing with the wiper motor control system
• Degradation of exposed impedance sensors
• Sunlight interference of IR sensor performance

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Future Work

• Addition of speech recognition capabilities
• Activation of window control
• Activation of headlights
• Fog detection

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Questions

• If you build it, they will come.