Patent ID: 6518704
Filing Date: 2003-02-11
Classification: B60Q

Abstract:
A method for automatically switching the lights of a vehicle on and off, comprising the steps of:A) determining the driving speed of the vehicle; B) determining the brightness H1 within a first cone that lies in front of the vehicle, looking into the driving direction, where the first cone has a large cone angle, and where the tip of the cone lies inside the vehicle; C) determining the brightness H2 within a second cone that lies in front of the vehicle, looking into the driving direction, where the cone angle of the second cone is smaller than that of the first cone, and where the tip of the second cone lies inside in the vehicle; D) determining the brightness H3 within a third cone that lies in front of the vehicle, looking into the driving direction, where the cone angle of the third cone is smaller than that of the first cone, where the tip of the third cone lies inside the vehicle, where the longitudinal axis of the third cone is elevated in the driving direction relative to the longitudinal axis of the second cone, as viewed from the side, and where the envelope of the third cone that lies outside its tip is located within the envelope of the first cone; E) switching the lights of the vehicle on if at least one of: the driving speed is greater than zero and the brightness values H1, H2 and H3 each fall below a minimum value Hmin,1 over a driving distance S1; the driving speed is greater than zero and the brightness value H2 is less than the brightness value H1 by an amount &Dgr;Hmin,1 over a driving distance S1 and the brightness value H3 is greater than the brightness value H2 by less than an amount &Dgr;Hmin,2 over a driving distance S1; and the driving speed is equal to zero and the ignition is switched on and the brightness values H1, H2 and H3 each fall below a minimum value Hmin,1 during a time interval &Dgr;Tmin,1; and F) switching the lights of the vehicle off if one of: the driving speed is greater than zero and the brightness values H1, H2 and H3 each exceed a minimum value Hmin,2 over a driving distance S1; and the driving speed is equal to zero and the ignition is switched on and the brightness values H1, H2 and H3 each exceed a minimum value Hmin,2 during a time interval &Dgr;Tmin,2.