This system processes far infrared radiation, which minimizes non-essential information placing a greater emphasis on pedestrian and animal, allows for a range of 300 meters or nearly 1,000 feet, and avoids “dazzle” from headlights, road lights and similar intense light sources. In 2008 vehicles are added with a pedestrian detection system which flashes a caution symbol on navigation / information screen and head up display when it detects a pedestrian. The objective of the pedestrian warning algorithms is to accurately detect pedestrian and provide the driver with informative warning. In eyes of the driver, the end product of the good system provides the timely warning and possibly, additional information such as the position of the pedestrian or an overlaid on the night vision display. There are two different technologies in the market for night vision system. Far infrared (FIR) also called passive infrared And Near infrared (NIR) also called active infrared.
What is Night Vision System?
The night vision system provides the driver with the black and white image of the driving environment ahead of the vehicle in the central information display (CID). The night vision is 100% passive system without active infrared illumination. Objects situated ahead of the vehicle are shown in varying degrees of the brightness depending upon the temp of these objects. This enables the driver to detect in good time heat emitting objects such as people, animals and the other vehicles.
An Automotive night vision system is system to increase the vehicle driver’s perception and seeing distance in darkness or poor weather beyond the reach of vehicles head light. They are currently offered as optional equipment on certain premium vehicles the camera is connected to the front grill of automotive.
USE OF THE NIGHT VISION SYSTEM IN CARS
This thermal image is recorded with a far Infrared camera (FIR) via a special imaging sensor which detects the infrared radiations in a specific wavelength range. The vehicle system is distinguished from infrared system with active illumination by its long range, and its clearly structured image. Infrared energy coming from an object is focused by the optics onto an infrared detector. A thermal imaging camera can produce a comprehensive image on which the smallest of the temperature difference can be seen. Contrary to other technologies, such as e.g. light amplification, that need at least small amount of light to generate an image, thermal imaging needs no light at all. Improve vision in twilight and darkness and the display does not dazzle by the head lights of the oncoming vehicles.
METHODS OF NIGHT VISION SYSTEM
Image Intensification System
Image intensification systems support direct observations by amplifying low levels of available light. They do not ‘turn night into day’ Nor do they overcomes the problems that affect vision in low light environments. The image intensifier is a vacuum-tube based device that converts invisible light from an image to visible light so that a objects in the dark can be viewed by a camera or the naked eye. When light strikes a charged photocathode plate, electrons are emitted through a vacuum tube that strike the micro channel plate that cause the image screen to illuminate with a picture in the same pattern as the light that strikes the photocathode, This is much like a CRT television, but instead of color guns the photocathode does the emitting. The intensified image is, typically, viewed on a phosphor screen that creates a monochrome, video-like image, on the user’s eyepieces.
A special lens focuses the infrared light emitted by all of the objects in view. The focused light is scanned by a phased array of infrared-detector elements. The detector elements create a very detailed temperature pattern called a thermo gram. It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermo gram. This information is obtained from several thousand points in the field of view of the detector array. The thermo gram created by the detector elements are translated into electric impulses. The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display. The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the image.
SYSTEM COMPONANTS AND THEIR WORKING
The vehicle with Night Vision system consists of the following components:
Night Vision camera with camera bracket and camera washer
Night Vision control unit
Button in light switch center
These main components of the night vision system are explained one by one below:
1. Night vision control unit
2. Controller display
4. Instrument Cluster
5. Button in light switch center
6. Night vision camera