Transcript Automated Windshield Wiper System

Automatic Windshield Wiper system
E-552
Sensors and Actuators
INSTRUCTOR: DR. Mohan Krishnan
Presented by:
Divesh Mittal
Steven Lee
Contents
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Objective / Introduction
Physics of Optical Sensor
Practical Setup
LabviewTM code/ Flow chart
Conclusion / Final Comments
Question???
Objective
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Selection and study of particular application
of sensor.
Automated windshield wiper system.
Prepare demo setup.
Automated Windshield Wiper System
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What is automated windshield wiper system?
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Who commercialized it?
Significance
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Active Safety
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Automation better than manual
Possible Transduction Mechanism
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Conductive transduction mechanism
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Piezoelectric transduction mechanism
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Optical transduction mechanism
Where are we??
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Objective
Physics of Optical Sensor
Practical Setup
LabviewTM code/ Flow chart
Conclusion / Final Comments
Question???
Physics of Optical Sensor
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Optical sensor works on concept of reflection and
refraction.
At critical angle of incidence only reflection occurs.
θr
Air
Refraction
Air
Glass
Glass
θi
θi
Reflection
(a) Reflection and Refraction
θi>θcrit
Total Internal
Reflection
(b) Total Internal Reflection
Physics of Optical Sensor
Contd..
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Critical angle of incidence for some material
combinations
Material
Critical angle
Windshield Glass / Air
41.15 degree
Windshield Glass / Water
61.28 degree
Windshield Glass / Ice
59.52 degree
Windshield Glass / PVC
76.83 degree
PVC / Air
42.52 degree
Physics of Optical Sensor
contd..
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Angle of incidence is kept slightly more than
critical angle for Windshield material/air
combination.
Presence of rain changes critical angle value.
Where Are We??
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Objective / Introduction
Physics of Optical Sensor
Practical Setup
LabviewTM code/ Flow chart
Conclusion / Final Comments
Question???
Practical setup
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Servo Motor
Wiper
PMMA plate
PMMA 90∘Prism
Phototransistor: QSD124 880nm wave length
IR LED: QED223 AlGaAs 880nm
Resistor: 1KΩ for Phototransistor; 910Ω for IR LED.
PCI DAQ 9024E
Practical setup
Measure
area
2
Plastic
1
3
Air
Prisms
IR LED
IR Phototransistor
Practical Setup
Rain Sensor
Measure Area
Practical Setup
IR
Phototransistor
IR LED
Where Are We??
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Objective / Introduction
Physics of Optical Sensor
Practical Setup
LabviewTM code/ Flow chart
Conclusion / Final Comments
Question???
RainSensor
Start
Labview coding
Read Rain
Sensor
Data from
DAQ card
Get the average
voltage
Differential
Get the peak data
Average voltage < 4.5 V ?
Or
Peak data >10
Yes
Turn on wiper
No
Control Chart
Labview
IR LED
DAQ card
Rain
IR Phototransistor
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PC
Wiper
Servo Motor
Wiper
Wiper System
Demo Video
Where Are We??
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Objective / Introduction
Physics of Optical Sensor
Practical Setup
LabviewTM code/ Flow chart
Conclusion / Final Comments
Question???
LabviewTM Results
No rain condition
Less water on windshield
More water on windshield
Final Comments/ Conclusion
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Mechatronic systems are best option for
active safety systems.
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Rain sensor is effective control system to
replace manual wipers.
Limitations
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Motor speed constant
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Smaller sensitive area
Questions