Automatic Adjustment REarview mirror
TYPE
Sensors and Actuator Project
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TEAM
Shannelle Smith
Rachel Warne
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DATE
Spring, 2020
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TOOL USED
SolidWorks, Word, Autodesk Tinkercad, Fritzing
OVERVIEW
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This project was to design the automatic adjustment rearview mirror to help drivers during the night by automatically adjusting the mirror between day and night modes when high-intensity headlights from a trailing vehicle, such as high beams and LED lights, are reflected off the rearview mirror.
The goal for this project was to allow the driver to see a dimmer reflection and stay focused while driving.
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MY ROLE
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I took part in code programming and designed the circuits.
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CHALLENGE
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"How can we differentiate between the light that only passed by and
following the high beam of the car?"
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PROBLEM DESCRIPTION
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Most rearview mirrors in vehicles are not simply flat mirrors. They are composed of a mirror with an angled piece of glass in front of it. This allows for two different modes, a day mode, and a night mode. In the day mode, the driver sees the reflection from the mirror. However, by flipping a tap at the bottom of a mirror, the angle between the driver and the mirror changes, and the driver sees a reflection off the glass. This reflection is dimmer than the direct image and can limit the blinding effect of a vehicle with high beams following a driver.
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Currently, this switch between day and night mode requires manual input from the driver. A driver must take the time to recognize the high beams, determine if it is annoying enough to warrant action, then take a hand off the wheel and their eyes off the road to switch the mirror into night mode. Then, after the vehicle with high beams moves away, the driver must remember to flip the mirror back into day mode. This is because having the mirror in night mode limits visibility if the cars behind are not using high beams.
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Therefore, we built a rearview mirror that automatically rotates up and down when it sense high light intensity. This will help facilitate visibility through the rearview mirror and on the road when high beams or LED headlights are shined on the mirror.
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CONCEPT
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The rear-view mirror was programmed and designed based on the schematics that can be seen in Figure below which is the design flow chart. Where if the high-intensity beam hit the light sensor there will be voltage changes that could generate the servo motor to rotate 15° causing the rearview mirror will tilt upwards, and if the beam intensity is decreasing or below 1023 lux the motor will rotate reversely to 15° where the original position of the mirror.
CODE PROGRAMMING
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The code programming that used to control the motor to rotate the rearview mirror from the original position is attached in the appendix. If the light sensor detects a high light intensity (1023 lux) continuously for 10 seconds, the servo motor will rotate the rearview mirror counterclockwise 15° and will rotate back clockwise if the intensity decreases. If the intensity of light is below 1023 lux, the servo motor will not rotate, and the rear-view mirror will remain in the original position which is called “day mode.”
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FINAL DESIGN
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The design of this system includes a rearview mirror, an Arduino, a phototransistor light sensor, a 10k resistor, a breadboard, jumper cables, a servo motor, a battery and two small beams that will be used to secure the motor and rotate the mirror. The phototransistor light sensor, resistor, and Arduino will be connected to the breadboard by using jumper cables. These components will be hidden within a casing behind the mirror in order to avoid clutter around the mirror. The light sensor will be mounted onto the top of the stem of the rearview mirror where it will be able to detect when
high beams or LED lights are shined directly onto the mirror. This light sensor will be used to measure the intensity of the light that is shined on the rearview mirror. Once the light intensity shined on the mirror reaches 1023 lux, the sensor will signal the motor to activate and rotate the mirror upwards 15° in order to help reduce the intensity of the light that is shined through the mirror. After the light intensity on the mirror is reduced, the sensor will then signal the motor to revert the mirror back to its “dead reckoning position” or original position. The motor will be connected to the Arduino where it will be programmed to follow such instructions. The resistor will be used to regulate the voltage across the system.
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REFLECTION
Key Learning
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Improved understanding of code programming of real-life situations.
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Improved understanding of the scheming of the electric circuit.
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