automatic windshield wiper system e-552 sensors and actuators instructor: dr. mohan krishnan
DESCRIPTION
Automatic Windshield Wiper system E-552 Sensors and Actuators INSTRUCTOR: DR. Mohan Krishnan. Presented by: Divesh Mittal Steven Lee. Contents. Objective / Introduction Physics of Optical Sensor Practical Setup Labview TM code/ Flow chart Conclusion / Final Comments Question???. - PowerPoint PPT PresentationTRANSCRIPT
Automatic Windshield Wiper systemE-552
Sensors and ActuatorsINSTRUCTOR: DR. Mohan Krishnan
Presented by:Divesh MittalSteven Lee
Contents
Objective / Introduction Physics of Optical Sensor Practical Setup LabviewTM code/ Flow chart Conclusion / Final Comments Question???
Objective
Selection and study of particular application of sensor.
Automated windshield wiper system. Prepare demo setup.
Automated Windshield Wiper System
What is automated windshield wiper system?
Who commercialized it?
Significance
Active Safety
Automation better than manual
Possible Transduction Mechanism
Conductive transduction mechanism
Piezoelectric transduction mechanism
Optical transduction mechanism
Where are we??
Objective Physics of Optical Sensor Practical Setup LabviewTM code/ Flow chart Conclusion / Final Comments Question???
Physics of Optical Sensor
Optical sensor works on concept of reflection and refraction.
At critical angle of incidence only reflection occurs.
Air
Glass
Air
Glass
(a) Reflection and Refraction (b) Total Internal Reflection
θr
θi θi
θi>θcritReflection
Refraction
Total Internal Reflection
Physics of Optical Sensor Contd..
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..
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??
Objective / Introduction Physics of Optical Sensor Practical Setup LabviewTM code/ Flow chart Conclusion / Final Comments Question???
Practical setup
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
1
2
3
Prisms
Air
IR LED IR Phototransistor
Measure area
Plastic
Practical Setup
Rain SensorMeasure Area
Practical Setup
IRPhototransistor
IR LED
Where Are We??
Objective / Introduction Physics of Optical Sensor Practical Setup LabviewTM code/ Flow chart Conclusion / Final Comments Question???
RainSensorStart
Read Rain Sensor
Data from DAQ card
DifferentialGet the peak data
Get the average voltage
Average voltage < 4.5 V ? Or
Peak data >10
Turn on wiper
No
Yes
Labview coding
Control Chart
IR LED
IR PhototransistorDAQ card
Servo Motor
Wiper
Wiper
Wiper System
Rain-
Labview
PC
Demo Video
Where Are We??
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
Mechatronic systems are best option for active safety systems.
Rain sensor is effective control system to replace manual wipers.
Limitations
Motor speed constant
Smaller sensitive area
Questions