Rain Sensor Description and Operation

Description

Integrated Rain Sensor

1. 1
   Wiper Control System: When the "AUTO" switch signal is received from the multifunction switch on the right, the integrated rain sensor detects the amount of rainfall. The sensor is installed inside the upper part of the front windshield. This system automatically controls the operating duration and speed of the wiper based on the measured amount of rainfall, even if the driver does not operate the wiper switch.
2. 2
   Automatic Lighting Control System: When the "AUTO" signal is received from the left multifunction switch, the integrated rain sensor mounted on the windshield detects the light level and controls the headlamp operation and the interior multimedia screen brightness. Based on the measured brightness, this system automatically adjusts the headlamp and the interior multimedia screen brightness, even if the driver does not press the light switch.
3. 3
   Central Air Conditioning System: When the "AUTO" signal is received from the air conditioner control system, the integrated rain sensor detects the amount of sunlight based on the direction of sunlight. This system automatically controls the cooling system based on the measured amount of sunlight, even if the driver does not turn on the air conditioner switch.

   

Functions and Operating Principle

1. 1
   Rain Amount Detection: Light (beam) emitted by the light-emitting diodes (LEDs) is totally reflected on the outer surface of the windshield and returns to the photodiodes. When water is present on the outer surface of the windshield, the light is optically separated and partially reflected, and the remaining brightness is measured by the photodiodes. Water remaining on the windshield prevents total reflection of the light. The loss of brightness caused by this indicates how wet the glass surface is.
2. 2
   Light Detection: Light brightness is measured by diodes using infrared light. The brightness outside the vehicle is measured in two directions: (a) upward and (b) forward. The measured light amount is used to determine whether it is day or night.
3. 3
   Solar Load Detection: The system measures the amount of sunlight on the left and right sides and controls the air conditioner on the driver side or passenger side.

The integrated rain sensor consists of 2 LEDs and 2 photodiodes for rain detection, 2 photodiodes for light detection, 1 photodiode for solar load detection, and a bracket.

1. 1
   When the "AUTO" signal is received from the right multifunction switch, the integrated rain sensor detects the amount of rainfall and controls the wiper motor.
2. 2
   When the "AUTO" signal is received from the left multifunction switch, the integrated rain sensor detects the brightness and controls the headlamp and interior multimedia system brightness.
3. 3
   When the "AUTO" signal is received from the air conditioner control system, the integrated rain sensor detects the amount of sunlight and controls the air conditioning system.
4. 4
   Dust on the measuring surface and other surfaces in the light path (surface of the LEDs and photodiodes, optical fiber, bracket, and glass surface near the windshield contact area) weakens the received light.
5. 5
   Movement of the windshield and bracket
6. 6
   Movement of the bracket due to vibration
7. 7
   Damaged wiper blade
8. 8
   Damaged Headlamp
9. 9
   Damaged Multimedia Device
10. 10
    Damaged Air Conditioning System

If the integrated rain sensor does not operate or operates incorrectly, the driver must turn on the wiper switch manually. If the integrated rain sensor does not operate or is malfunctioning, the driver must turn on the headlamp switch manually. If the integrated rain sensor does not operate or operates incorrectly, the driver must turn on the air conditioner switch manually.

1. 1
   Rain Sensor Operating Condition

   Operation Mode	Operation
   Direct Mode	This is the normal operating condition of the built-in rain sensor when the wiper switch is in the "AUTO" position and the sensor detects a dry windshield. Based on this condition, the built-in rain sensor determines the wiper operating mode according to the amount and duration of precipitation.
   Intermittent Mode	The built-in rain sensor activates intermittent mode when wiper operation is performed consecutively more than two times with an interval of 0.5 to 5 seconds.
   Low speed	Wipers operate continuously at low speed
   High speed	Wipers operate continuously at high speed

2. 2
   Light Sensor Operating Condition

   Operation Mode	Operation
   Automatic Mode	This is the normal operating condition of the integrated rain sensor when the headlamp switch is in the "AUTO" position and the sensor detects the light level. Based on this condition, the integrated rain sensor determines the operation of the headlamp and interior multimedia according to the measured amount of light.
   Low Beam On	The lamp and multimedia turn on at medium brightness.
   High Beam On	The lamp and multimedia turn on at maximum brightness.

3. 3
   Solar Load Sensor Operating Condition

   Operation Mode	Operation
   Automatic Mode	This is the normal operating condition of the integrated rain sensor when the air conditioner switch is in the "AUTO" position and the sensor has detected the amount of sunlight. Based on this condition, the integrated rain sensor determines the operation of the air conditioning system according to the amount of sunlight.
   Manual Mode	Cooling intensity is adjusted manually.

4. 4
   When ice or foreign objects are present in the detection area, the built-in rain sensor cannot correctly recognize the operating conditions.
5. 5
   Rain sensor

   Special Condition	Operation Based on Special Condition Detection
   Hesitation	When the built-in rain sensor detects a high level of water (splash) in Direct or Intermittent mode, the system switches from park mode to High speed. Then wiping is performed once in High speed mode and once more in Low speed mode. If the precipitation condition does not change after wiping, it returns to the original state (Direct or Intermittent).
   Smearing	Smearing is a thin oil film that dries quickly and occurs when a small amount of rain drops are wiped by a dirty or worn wiper blade. The operating signal should not be issued when smearing occurs in the Continuous or Intermittent mode.
   Mud	If no change is detected after wiping, the built-in rain sensor determines that the windshield is contaminated. In this condition, the operating signal must not be output. If the windshield becomes clean (for example, by washer fluid), the built-in rain sensor returns to the normal condition.
   Automatic Day/Night Sensitivity Change	The integrated rain sensor automatically adjusts the day/night sensitivity using the day and night sensor.
   Ambient Light Level Compensation	The system works normally, compensating for interference caused by lighting in the surrounding area.
   Washer Fluid	The built-in rain sensor does not respond to washer fluid in washing mode. In other words, the wiping speed does not change even when washer fluid is sprayed (automatic operation of the washer pump does not affect the operation of the built-in rain sensor).

6. 6
   Light Sensor

   Special Condition	Driving in Special Conditions
   Pedestrian Overpasses / High-rise Buildings / Street Trees	The built-in rain sensor prevents the headlights from flashing on when it detects brightness while driving past pedestrian overpasses, high-rise buildings, or street trees during the day. However, the headlights may turn on when the sensor detects nighttime conditions while passing the locations listed above.
   Tunnels	The built-in rain sensor recognizes a tunnel when the vehicle passes through it during the day. When entering a tunnel, the built-in rain sensor recognizes the tunnel and immediately turns on the headlights, and turns them off a few seconds after exiting the tunnel.