Automatic light intensity control device for vehicle rear lamps in response to changes in visibility distance and its control method

An automatic light intensity control method for vehicle rear lamps in response to changes in visibility distance, the automatic light intensity control method comprising:

• a visibility distance measurement step (S10) in which a visibility distance measurement unit 10 mounted on a driving vehicle measures a visibility distance of a driving road in real time;
• a speed detection step (S20) in which a speed detection unit 30 detects the speeds of a driving vehicle (LV) and a following vehicle (FV) in real time and transmits the detected speeds to a light intensity calculation and control unit 20;
• a braking distance calculation step (S30) in which the light intensity calculation and control unit 20 calculates a difference(s) in an appropriate braking distance between the driving vehicle (LV) and the following vehicle (FV) based on the speed (Vl) of the driving vehicle and the speed (Vf) of the following vehicle;
• an appropriate light intensity calculation step (S40) in which an light intensity calculation and control unit 20 mounted on the driving vehicle calculates an appropriate light intensity (Cd) using visibility distance information (Md);
• and
• a light intensity control step (S50) in which the light intensity calculation and control unit 20 controls the light intensity of rear lamps RL in real time,
• wherein the appropriate light intensity (Cd) calculated by the light intensity calculation and control unit 20 is determined through regression analysis on accumulated data accounting the driver's perception and reaction, obtained by measuring the light intensity of the rear lamps RL and a braking deceleration according to the visibility distance, and the appropriate light intensity (Cd) is determined as a minimum light intensity that satisfies a standard braking deceleration,
• wherein when the speed (Vf) of the following vehicle (FV) is higher than the speed (Vl) of the driving vehicle (LV), the appropriate light intensity calculation step (S40) determines the appropriate light intensity (Cd) by calculating the difference(s) in the appropriate braking distance between the driving vehicle (LV) and the following vehicle (FV) and correcting the visibility distance information (Md), and
• wherein the rear lamps RL is further provided with an infrared LED, and if the visibility distance information (Md) is below a reference value, an infrared control unit turns on the infrared LED of the rear lamps RL.