ece 480 – team 6
DESCRIPTION
Capacitive Rain Sensor for Automatic Wiper Control. ECE 480 – Team 6. In Order of Presentation: Ishaan Sandhu Danny Kang Arslan Qaiser Eric Otte Anuar Tazabekov. Outline. Introduction Design Requirements Proposed Design Solution Testing Results Budget Demonstration - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/1.jpg)
1
ECE 480 – Team 6In Order of Presentation:
Ishaan SandhuDanny Kang
Arslan QaiserEric Otte
Anuar Tazabekov
Capacitive Rain Sensor for Automatic Wiper Control
![Page 2: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/2.jpg)
2
Outline
• Introduction
• Design Requirements
• Proposed Design Solution
• Testing Results
• Budget
• Demonstration
• Conclusions
![Page 3: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/3.jpg)
3
Introduction
• Automotive Safety and Convenience• Automatic Headlights• Hands-Free Calling• Automatic Braking• Automatic Windshield Wipers
– Currently Optical (Expensive, Inaccurate)– DT6 Proposes Using a Capacitive Based Sensor
![Page 4: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/4.jpg)
4
Capacitive Sensor Basics
Sensor Traces Form Base
Capacitance
E-field Generated by Applying AC
Voltage
Objects Interfere with E-field
Capacitance of Sensor Changes
![Page 5: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/5.jpg)
5
Design Requirements
Functionality• Detect rain through 6 mm of glass
• Output control signals to wipers
Accuracy• Differentiate multiple levels of rain
• Ignore false stimuli on windshield, i.e. hands and dirt
Compatibility• Fit in existing housing area (1250 mm2)
• Mount via adhesive to windshield
Cost• Production cost < $16 per unit
![Page 6: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/6.jpg)
6
System Block Diagram
Capacitive Sensor Control Unit Wiper
System
![Page 7: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/7.jpg)
7
Design Flowchart
Voltage Regulator (5 V DC)
Keep Wipers Off
Capacitive Sensor Traces
on PCB
Activate Wipers
Capacitive-to-Digital
Converter Circuit
Microcontroller
YES
NO
I s Capacitance Between
X Farads Y ≤ ≤ ?
Control Unit
![Page 8: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/8.jpg)
8
Sensor TracesCOMSOL • 3D Modeling Software • Visual User Interface• Calculates the base
capacitance • Can model dielectrics
– Top layer– Bottom Layer
• Simulates electric field lines– Sensitivity
![Page 9: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/9.jpg)
9
Capacitance-to-Digital Converter
Analog Devices AD7745
• Industry-leading accuracy down to 4 fF change in capacitance
• Interfaces with sensor traces to monitor capacitance (+/- 4 pF)
• Converts changing capacitance to 24-bit digital output signal
• Output routed to PIC using the I2C communication system
Make text larger
![Page 10: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/10.jpg)
10
Microcontroller
Microchip PIC16F1826
• 8-bit microcontroller, programmable in C code
• Initializes and configures AD7745 for operation
• Streams data from AD7745 and compares to known data ranges
• Data falling in range will activate appropriate wiper control signals
Make text larger
![Page 11: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/11.jpg)
11
BudgetCOMPONENT COST
PIC16F1826 Microcontroller $0.90
AD7745 CDC $4.50
ADP3301-5 Voltage Regulator $1.40
Surface-mount Passive Components $0.10
Two-layer PCB Production and Assembly $4.00 (est)
Plastic Enclosure $0.50 (est)
Total $11.40 (est)
![Page 12: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/12.jpg)
12
Capacitive vs. Optical
Design Team 6 Supplier (TRW) Change
Technology Capacitive Optical
Cost per Unit $11.40 $16.41 31% ↓
Physical Size 1,750 mm2 3,850 mm2 46% ↓
Detection Area 960 mm2 560 mm2 72% ↑
Clear line of site No need Required
![Page 13: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/13.jpg)
13
Software
Start
Login
Main
Wait for UI
Start Reset
Clear all Fields
Get Data
Graph and Interpret
Start
Wait for Interrupt
Initialize
Get Data
Visual Basic Application Microcontroller
![Page 14: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/14.jpg)
14
Demonstration
![Page 15: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/15.jpg)
15
Conclusions
• Successful completion of the project• Exceeds all design requirements• Higher accuracy• Larger sensing area• Smaller enclosure• Significant savings
![Page 16: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/16.jpg)
16
Q & A
![Page 17: ECE 480 – Team 6](https://reader036.vdocuments.mx/reader036/viewer/2022062501/56815cab550346895dcaac40/html5/thumbnails/17.jpg)
17
Thank You