1. Field of the Invention
The present invention relates to an alerting system of a vehicle deviating from its traffic lane. Particularly, it relates to an automatic alerting system of a vehicle when it deviates from its traffic lane. The advantages and functions of this invention include: having a changeable judging base depending on its environment, lowering the possibility of misjudging caused by shadow, and having several post-processing steps.
2. Description of the Prior Art
Referring to FIGS. 1 and 2, one traditional alerting system of a vehicle on a highway can be seen as the U.S. Pat. No. 4,143,263 entitled “Highway Line Detector”. Its publication date is Mar. 6, 1979. A car 80 has two sides. Each side is disposed with an illuminating element 81 and a photodetector 82 (only describing one side of the car). When this car deviates toward a white side line 92. The intensity of the reflected light becomes stronger (it means the current/voltage becomes bigger). Then, the detected current/voltage can be compared with a fixed reference value 84 (current/voltage). If the detected one is larger, then a warning signal is generated.
However, it has the following disadvantages:
[1] Its judging base is not depending on its environment. No matter it is a sunny day, a cloudy day or a rainy day, the detected electric signal is always compared with a fixed reference value 84. Thus, it is very easy to cause a misjudging. Particularly, in a brighter or a darker environment, their reflected lights are different. But, the judging base (means the reference value 84) always remains unchanged, no matter the environment becomes brighter or darker. Thus, the entire system is not reliable.
[2] The possibility of misjudging caused by shadow is too high. When there is another fast-moving car in the neighboring lane, its shadow will move over the detected area of the traditional car. So, the detected electric signal will drop down (in the shadow) and then rise up sharply (while the shadow is leaving). It could cause the misjudging of the traditional system (send out a wrong warning signal). On a highway, there are lots of cars. So, it is very possible to be influenced by any neighboring car's shadow. Therefore, the possibility of misjudging caused by shadow is too high.
[3] Lack of suitable post-processing steps. In the traditional system, the warning is just an alarm sound. In case the driver cannot quickly react or the driver suddenly becomes unconscious (due to faint, sunstroke, shock, etc.), the vehicle will deviate to one side. Finally, it causes a car accident. Even the car accident happens, there is no any automatic informing system to inform a specific person (such as police officer, family member, etc.) via telecommunication equipment.