Rain Sensors | Light Sensors | Optoelectronic Sensors | Passive Light Sensor

Rain sensor systems:

Opto electronic sensors are used in a reflective mode in rain sensor systems to detect the presence of water on the windshield so that the windshield wipers can be controlled automatically.

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An LED emits light in such a way that when the windshield is dry almost the entire amount of light is reflected onto a light sensor. When the windshield is wet, the reflective behavior changes: the more water there is on the surface, the less light is reflected. In the new rain sensor, infrared light is used instead of conventional visible light. This means that the sensor can be mounted in the black area at the edge of the windshield and cannot be seen from outside.

Working Operation:

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An infrared beam is reflected off the outer windshield surface back to the infrared sensor array. When moisture strikes the windshield, the system detects a reflection to its infrared beam. Advanced analogue and digital signal processing determines the intensity of rain. The sensor communicates to the wiper control module, which switches on the wiper motor and controls the wipers automatically, according to the moisture intensity detected.

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Depending on the quantity of rain detected, the sensor controls the speed of the wiper system. In conjunction with electronically controlled wiper drive units, the wiping speed can be continuously adjusted in intermittent operation. In the event of splash water – as when overtaking a truck – the system switches immediately to the highest speed.

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The new rain sensor offers further options. For example, it can be used to close windows and sunroofs automatically if the vehicle is parked and it starts to rain. It can even be fitted with an additional light sensor to control the headlights – at night or at the entrance to a tunnel, the lights can be switched on without any intervention by the driver.

For Windshield wipers working operation Click this Link.

Light Sensors:

Automatic lighting of the headlights is controlled by a passive light sensor. It measures available light using a set of photo-electric cells.

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The light sensor comprises three lenses that focus the light onto three photo-electric cells. This allowed “the luminous space” surrounding the vehicle into several zones through the directivity of each basic lens cell pair.

  • Lens 1: Measure total ambient light
  • Lens 2: Intersect Front source of light
  • Lens 3: Distinguish Road Condition (Like brighter sunny weather condition or Dark tunnel)

By comparing the information gathered by these three devices, the system computer determines the situation with which the vehicle is confronted and commands the headlights in consequence.

Tandem Wipers | Windshield Wiper Blades | Electronic Wiper Control

Windshield Wipers:

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Conventional wiper drives have only one direction of rotation, and the direction of wiping is changed mechanically. The new electronically controlled motor reverses its direction of rotation at the turning point of the wiper – therefore, the mechanical components require less space.

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The electronic controller ensures a maximum visibility area at all times, irrespective of wiping speed, coefficient of friction or wind force. Through exact adherence to the wiping angle, it is possible to reduce the tolerance distance to the edge of the windscreen to a minimum and thus to enlarge the swept area. The controller can detect obstacles such as packed snow at the reversing points and automatically reduces the swept area to prevent the system from blocking. The speed of the motor is reduced before reversal to ensure quiet running.

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The electronic speed controller is also very practical in conjunction with a rain sensor: depending on the quantity of water on the windshield, the drive unit can be operated at a continuously variable wiping speed.

The electronically controlled wiper motor also allows the use of two-motor wiper systems. Each wiper arm is moved by its own drive unit, and the electronic controller is responsible for the coordination of the movements.

Advantages:

  • This system requires no connecting rods
  • Reduced space requirements and
  • Lower weight.

Features & Benefits:

An extended parking position is available as an additional function: this means that when the wipers are switched off, the wiper arms are parked under the trailing edge of the bonnet. This improves the aerodynamics of the vehicle. Driving noise is reduced and the driver’s field of vision is enlarged. At the same time, the risk of injury is reduced in the event of accidents with pedestrians and two-wheeled traffic.