Method of automatically controlling exterior lighting of a vehicle

Abstract

The object of the invention is a method of automatically controlling exterior lighting of a vehicle (1) comprising an automatic adjustment of exterior lighting of the vehicle (1) between a first light mode, a second light mode, and a third light mode based on ambient lighting intensity information. In the first light mode, at least dipped headlights (2) and rear marker lights (3) are on. In the second light mode, daytime running lights (4) are on, wherein the dipped headlights (2) and the rear marker lights (3) are off in the second light mode. In the third light mode, the daytime running lights (4) and the rear marker lights (3) are on, wherein the dipped headlights (2) are off in the third light mode. The method comprises the steps of comparing the ambient lighting intensity with a specified first range of the ambient lighting intensity and issuing an instruction to start the first, the second or the third light mode by the control unit (5), when the ambient lighting intensity is in the specified first, second, or third range of the ambient lighting intensity, respectively.

Description

[0001] Method of automatically controlling exterior lighting of a vehicle

[0002] Technical Field

[0003] The present invention relates to a method of automatically controlling exterior lighting of a vehicle, in particular a combination of daytime running lights, dipped headlights, and rear marker lights, in order to increase the safety vehicle operation and reduce carbon dioxide emissions.

[0004] Background of the Invention

[0005] Most current car manufacturers switch the lights of their vehicles based on a light scheme that comprises only two light modes (daytime running lights or dipped headlights), separated by ambient lighting intensity boundary values. In other words, for example, daytime running lights are switched on with respect to the ambient lighting intensity in a range of approximately 1200 lx to 100000 lx, for example, by exceeding the value of 4500 lx, and dipped headlights are switched on when the intensity falls below the value of 2800 lx. The legislative limit of the ambient lighting intensity value from which daytime running lights can be used instead of dipped headlights is 1000 lx in the Czech Republic, wherein the above mentioned 1200 lx represents a compromise between legislation and traffic safety. In reality, there are cases where the car is lit only by the front daytime running lights and it is difficult to see in the ambient lighting intensity boundary values, in darkness, fog, or rain. Conversely, there are also situations, e.g., due to shadows, where a car uses the dipped headlights on a clear day and thus produces more CO2 emissions without benefit.

[0006] At sunrise and sunset, the light intensity is high enough to automatically activate the front daytime running lights. As a result of the angle of sunshine being low, especially drivers driving against the sun are blinded and the ability to see the car in front of them is lower. Especially if it uses only the front daytime running lights for the lighting.

[0007] In the current state of the art, there are known methods of controlling lights that aim to increase the safety of vehicles that only use the daytime running lights for the lighting during their operation. One such solution is described, for example, in the document US20100213847, which discloses a method of controlling the daytime running lights of a car, where the daytime running lights are primarily switched based on external lighting intensity information (comparing the adjusted lighting intensity value and the current measured one). In addition, the possibility of switching the daytime running lights based on time information, for example from a GPS unit, which determines whether it is sunset / sunrise, is also disclosed. A disadvantage of switching the daytime running lights based on the time information from the GPS is a complete disregard of ambient conditions, wherein situations can arise where the car automatically switches on the daytime running lights based on the time information from the GPS even though there is currently fog or rain. Another disadvantage of the above solution is the poor visibility of the rear part of the vehicle in situations where the driver driving behind the described vehicle is blinded by the sun (i.e., situations where the sun is low above the horizon, i.e., it is sunrise / sunset), as only the daytime running lights are on.

[0008] In another document, GB2536683, a similar solution is provided, where again the daytime running lights are primarily switched based on external lighting intensity information (comparing the adjusted lighting intensity value and the current measured one). In addition, the lighting can be switched based on information (weather, sunset / sunrise, time, etc.) using a remote system. Based on all the available information, the probability of the current external weather conditions (rain, sunny weather, fog, night, etc.) is calculated and based on this probability the given light scheme of the car is switched. A disadvantage of such a solution is also the poor visibility of the rear part of the vehicle in situations where the driver driving behind the described vehicle is blinded by the sun (i.e., situations where the sun is low above the horizon, i.e., it is sunrise / sunset), as only the daytime running lights are on.

[0009] It would therefore be advisable to come up with a solution that would eliminate the above mentioned shortcomings, since the current vehicles comprise only two functional states of the exterior lighting and fail to adapt the car to the ambient conditions, and there are also gaps in visibility and efficiency due to the compromise boundary of the lighting intensity at which they switch. With the front daytime running lights, there are situations where the car is poorly visible and safety may be compromised. Dipped headlights lighting above the added value of visibility in turn increases CO2 emissions, as both the front and rear marker lights, the front dipped headlights, the number plate light, but also all the interior lighting and instrument backlighting are on on the car. Even when using LED technology, power consumption is in the order of tens of watts. In addition to the higher energy consumption, dipped headlights are subject to excessive wear and tear. The rising / setting sun reduces the driver’s ability to see, which is further hindered by the fact that automatic control of the lights only activates the front daytime running lights, and the vehicle is poorly visible from the rear.

[0010] Summary of the Invention

[0011] The above shortcomings are to a certain extent eliminated by a method of automatically controlling exterior lighting of a vehicle comprising an automatic adjustment of exterior lighting of the vehicle between a first light mode, a second light mode and a third light mode based on ambient lighting intensity information. In the first light mode, at least dipped headlights and rear marker lights are on, and in the second light mode, daytime running lights are on, wherein the dipped headlights and the rear marker lights are off in the second light mode. The essence of the method of the present invention lies in the fact that this method comprises the steps of:

[0012] - comparing an ambient lighting intensity measured by at least one light sensor with a specified first range of the ambient lighting intensity, a second range of the ambient lighting intensity and a third range of the ambient lighting intensity using a control unit, wherein the third range of the ambient lighting intensity lies above the first range of the ambient lighting intensity and the second range of the ambient lighting intensity lies above the third range of the ambient lighting intensity, issuing an instruction to start the first light mode by the control unit if the ambient lighting intensity is in the specified first range of the ambient lighting intensity,

[0013] - issuing an instruction to start the second light mode by the control unit if the ambient lighting intensity is in the specified second range of the ambient lighting intensity, and

[0014] - issuing an instruction to start the third light mode by the control unit if the ambient lighting intensity is in the specified third range of the ambient lighting intensity, wherein in the third light mode, the daytime running lights and the rear marker lights are on, wherein the dipped headlights are off in the third light mode.

[0015] As can be understood from the paragraph above, the individual light modes are defined by which lights are on and which are off. However, in the individual light modes, additional lights that are not declared to be off in the given light mode can be on, such as the number plate light or any interior lighting and instrument backlighting.

[0016] Thanks to the automatic adjustment of the exterior lighting between the three mentioned light modes, the vehicle can be better adapted to the ambient conditions, thereby continuously improving safety and reducing CO2 emissions. In the newly introduced third light mode, the dipped headlights are not on, which, in addition to reducing energy consumption, also leads to less wear and tear and thus to a longer lifetime of the dipped headlights. In this light mode, the rear marker lights are also on together with the daytime running lights, which improves safety in the sense that the vehicle is better visible to the vehicles driving behind it. Improving visibility is especially important in poor conditions - e.g., in fog, rain, or when the driver is blinded by the rising or setting sun.

[0017] For the automatic adjustment of the exterior lighting between the individual light modes, a control unit is used, which is adapted to control the individual lights, i.e., to turn them on and off. Various sensors are also connected to the control unit, as will be described below, either directly or via other control units or sub-units, wherein the connection itself is implemented using e.g. data wires. Alternatively, this connection can be implemented as a wireless one. The individual adjusted lights (at least the dipped headlights, the rear marker lights and the daytime running lights) are data-connected to the control unit, i.e., the control unit does not supply electrical energy to the individual lights but transmits a switching signal to the control sub-units of the lights, for example, which then ensure that electric current is supplied to the lights and that they are activated. Providing electric current to the lights can be accomplished, for example, by using an assembly of switching relays, or switching semiconductor elements and switching relays.

[0018] The control unit compares the ambient lighting intensity measured by the at least one light sensor with the specified first range of the ambient lighting intensity, the second range of the ambient lighting intensity and the third range of the ambient lighting intensity, wherein the third range of the ambient lighting intensity lies above the first range of the ambient lighting intensity and the second range of the ambient lighting intensity lies above the third range of the ambient lighting intensity. Therefore, in general, an upper limit h of the first range of the ambient lighting intensity, a lower limit hd of the third range of the ambient lighting intensity, an upper limit hh of the third range of the ambient lighting intensity and a lower limit d of the second range of the ambient lighting intensity can be defined, for which the following relation applies: h < hd < hh < d. The limits hh and hd (and by analogy also hh and d) can, in principle, coincide, but in practice, it is more preferable if there is a sharp inequality between them, as will be described below. Maintaining the above relation, the upper limit hh of the first range of the ambient lighting intensity may be selected from the range of 500 to 3000 lx, the lower limit hd of the third range of the ambient lighting intensity may be selected from the range of 500 to 5000 lx, the upper limit hh of the third range of the ambient lighting intensity may be selected from the range 3000 to 12000 lx, and the lower limit hd of the second range of the ambient lighting intensity may be selected from the range of 4000 to 15000 lx. The values of these limits are stored in the control unit, wherein to obtain the optimum limit values, it is preferable to perform practical testing. In view of the current legislation (see UNECE No 48, Annex 13, 2016), the upper limit I ih of the first range of the ambient lighting intensity is most preferably selected as 1000 lx, or as a value from the range of 1000 to 1500 lx.

[0019] The control unit issues an instruction to start the first light mode if the ambient lighting intensity is in the specified first range of the ambient lighting intensity. The first light mode thus corresponds essentially to low ambient lighting intensities, at which, for safety reasons, it is required that the dipped headlights and the rear marker lights are on.

[0020] The control unit issues an instruction to start the second light mode if the ambient lighting intensity is in the specified second range of the ambient lighting intensity. The second light mode thus corresponds essentially to high ambient lighting intensities, at which, for energy savings reasons, it is required that the dipped headlights and the rear marker lights are off.

[0021] The control unit issues an instruction to start the third light mode if the ambient lighting intensity is in the specified third range of the ambient lighting intensity. The third light mode thus corresponds to intensity values that are neither too low nor too high. In this mode, it is preferable, in order to save energy and reduce CO2 emissions, for the dipped headlights to be off, but it is also preferable for the rear marker lights together with the daytime running lights to be on in order to increase safety.

[0022] However, the above mentioned adjustment between the individual light modes can be subsequently re-adjusted according to an additional condition. This applies especially to the third mode, which can be started e.g. even if the ambient lighting intensity is in the second range of the ambient lighting intensity and if sunrise or sunset is detected at the same time.

[0023] The comparison is preferably based on input data which are obtained by continuous measurement of the ambient lighting intensity by the at least one light sensor at least in a wavelength range that corresponds to the visible region of electromagnetic radiation, i.e., in the range of approximately 380 to 750 nm. The continuous measurement of the intensity in the visible region enables the most efficient automated adjustment of the light modes in response to the current ambient conditions, and thus also the highest possible energy saving and CO2 emission reduction with a simultaneous safety improvement. Alternatively, in a less preferable embodiment, the measurement may be performed only when the ambient lighting intensity changes, wherein the control unit may receive a wake-up signal only when the measurement results in exceeding any of the limits of the individual ranges of the ambient lighting intensity. In such an alternative embodiment, the light sensor could be provided with a unit that has these limits or ranges of the ambient lighting intensities stored in memory.

[0024] The lower limit hd of the third range of the ambient lighting intensity is preferably higher than the upper limit h of the first range of the ambient lighting intensity, and the upper limit hh of the third range of the ambient lighting intensity is preferably lower than the lower limit hd of the second range of the ambient lighting intensity. This means that there are gaps or gray zones between the individual ranges where there is no change in the light mode. This detects a certain hysteresis of the light modes and prevents the light modes from being changed too often and in situations that do not correspond to the actual ambient conditions due to the large variance of the measured values. If there are such gray zones between the individual ranges, they are handled in automatic operation, i.e., operation, in which the exterior lighting of the vehicle is already in one of the light modes described above and the control unit automatically decides whether and which of the light modes will be started.

[0025] In practice, however, the automatic operation is typically preceded by a so-called initialization phase, where the exterior lighting of the vehicle should transition from a state that does not yet correspond to any of the light modes described above, to one of these light modes. This initialization phase no longer deals with these gray zones as it is necessary to adjust the exterior lighting into one of the light modes. In the initialization phase, e.g. the control unit may issue an instruction to start the first light mode if the ambient lighting intensity is lower than the lower limit hd of the third range of the ambient lighting intensity. The instruction to start the second light mode may be issued if the ambient lighting intensity is higher than the lower limit hd of the second range of the ambient lighting intensity, and the instruction to start the third light mode may be issued if the ambient lighting intensity is between the lower limit hd of the third range of the ambient lighting intensity and the lower limit d of the second range of the ambient lighting intensity. Alternatively, a different decision may be made in the initialization phase, e.g., the instruction to start the first light mode may be issued if the ambient lighting intensity is lower than the upper limit h of the first range of the ambient lighting intensity. The instruction to start the second light mode may then be issued if the ambient lighting intensity is higher than the lower limit hd of the second range of the ambient lighting intensity, and the instruction to start the third light mode may be issued if the ambient lighting intensity is between the upper limit h of the first range of the ambient lighting intensity and the lower limit hd of the second range of the ambient lighting intensity.

[0026] Preferably, the step of issuing an instruction to start the first light mode by the control unit is performed if the ambient lighting intensity is in the first range of the ambient lighting intensity for at least a specified time ti. The evaluation using this time parameter prevents unwanted turning on of the dipped headlights when passing through a short shaded space, for example under bridges, trees, and the like. Preferably, the step of issuing an instruction to start the second light mode by the control unit is performed if the ambient lighting intensity is in the second range of the ambient lighting intensity for at least a specified time t2. The evaluation using this time parameter prevents the unwanted turning off of the dipped headlights and the rear marker lights under boundary conditions with regard to maintaining safe visibility.

[0027] Preferably, the step of issuing an instruction to start the third light mode by the control unit is performed if the ambient lighting intensity is in the third range of the ambient lighting intensity for at least the specified time t3. The evaluation using this time parameter prevents the unwanted turning on of the rear marker lights during the transition from the second light mode and also the unwanted turning off of the dipped headlights during the transition from the first light mode under boundary conditions with regard to maintaining safe visibility.

[0028] The value ti can be selected from the range of 1 to 10 s, the value t2 can be selected from the range of 10 to 30 s, and the value t3 can be selected from the range of 10 to 20 s. It is true that the time parameter ti, which corresponds to the transition to the light mode with the dipped headlights turned on, should be smaller than both t2 and t3.

[0029] The step of issuing an instruction to start the third light mode by the control unit is preferably performed if the ambient lighting intensity is in the second range of the ambient lighting intensity and sunrise or sunset is detected at the same time. This is because at higher ambient lighting intensities, but also in a situation where the sun is low above the horizon, the driver of a vehicle, especially a vehicle driving against the sun, may be blinded by the setting or rising sun. In such a situation, it is desirable for the vehicle to have the rear marker lights turned on to make it more visible from the rear to drivers blinded in this way. Therefore, although the value of the measured ambient lighting intensity itself (e.g., even for a time longer than tz) corresponds to the second light mode, the exterior lighting is eventually adjusted to the third light mode because sunrise or sunset was detected.

[0030] Sunrise or sunset is preferably detected by measuring the ambient lighting intensity in a wavelength range that corresponds to the infrared region of electromagnetic radiation, i.e., approximately in the range of 760 nm to 1 mm. The detection of sunrise or sunset by measuring the intensity in the infrared region is made possible by the fact that sunrise or sunset are identically characterized by an increased intensity in the region of red, and especially also infrared light. The same light sensor used for measuring the ambient lighting intensity in the visible region may be used to measure the ambient lighting intensity in the infrared region, provided that the sensor is adapted to sense the ambient light intensity at least in the wavelength range that corresponds to the visible region and further at least in the wavelength range that corresponds to the infrared region. To determine whether sunrise or sunset is occurring, the boundary of the ambient lighting intensity for one or multiple wavelengths from the infrared region may be stored e.g. in the control unit. If the measured intensity is higher than this specified boundary, the control unit determines that sunrise or sunset is occurring.

[0031] Alternatively, a different sensor than the one used for measuring the intensity in the visible region may be used for measuring the intensity in the infrared region, e.g., an infrared sensor that is not adapted for measuring the lighting intensity in the visible region. By analogy, the light sensor thus does not have to be adapted for measuring the intensity also in the infrared region but e.g. only in the visible region.

[0032] Alternatively, sunrise or sunset may be detected in another way, e.g., by an incident light angle sensor, if this sensor is adapted to detect the incident light angle relative to a horizontal plane. It is therefore basically an angle lying in a vertical plane oriented in the longitudinal direction of the vehicle. This angle is, for example, oriented such that 0° corresponds to the situation where the light is incident on the vehicle from the front exactly in the horizontal direction, and 90° corresponds to the situation where the light is incident on the vehicle from above exactly in the vertical direction. If an angle smaller than a predetermined limit angle (which corresponds to sunrise or sunset) is detected in this way, preferably in the range of 0 to 45°, the control unit may decide that sunrise or sunset is occurring because the sun is low above the horizon and is incident on this sensor at a sufficiently small angle.

[0033] Preferably, if sunrise or sunset is detected, based on the measurement of the incident light angle relative to the vertical plane by the incident light angle sensor, it is determined whether there is a risk of blinding the driver. If it is determined that there is no risk of blinding the driver, the step of issuing an instruction to start the second light mode is performed by the control unit. This additional condition is added to the decision-making of the control unit in case the measured values of the ambient lighting intensity are high (i.e., they fall in the second range of the ambient lighting intensity) and at the same time there is sunrise or sunset occurring (i.e., the sun is low above the horizon). Based on measuring the incident light angle relative to the vertical plane, it can be determined whether the sun is shining directly at the driver and can thus blind them. However, if the rising or setting sun does not shine directly at the driver, it is preferable to turn off the rear marker lights and transition to the second light mode to save energy. The above mentioned angle relative to the vertical plane means e.g. an angle measured relative to the vertical plane oriented in the transverse direction of the vehicle, or, in other words, perpendicular to the direction of travel of the vehicle. Specifically, this means e.g. an angle that takes values of 0 to 180° in the front horizontal half-plane relative to the direction of travel and values of 180 to 360° in the rear horizontal half-plane relative to the direction of travel. If the measured incident light angle is within the predetermined range (preferably 30 to 150°), the control unit determines that there is a risk of blinding the driver as the vehicle is driving against the setting or rising sun.

[0034] The light sensor may use e.g. photodiodes, and the incident light angle sensor may also use photodiodes.

[0035] In addition to the light sensor and the incident light angle sensor, other sensors can be connected to the control unit, e.g., a sensor of the position of the direction indicator light control levers, a hazard warning signal sensor, a steering wheel angle sensor or a speed sensor. These sensors affect other functions of the lights that are not a direct function of the present invention. Among other things, based on these sensors, the control unit can turn on and off the direction indicator lights, turn on cornering lights, direct the light beam of the dipped headlights, switch the mode of the high-beam lights, and the like. Some sensors, for example the speed sensor, can override the method of controlling the exterior lighting of the vehicle. For example, at zero speed, the method of controlling the exterior lighting can be deactivated, and at non-zero speed, the method of controlling the exterior lighting can be activated.

[0036] The method of automatic controlling the exterior lighting of the present invention may comprise various combinations of the preferred features listed above, e.g., it may use time parameters but does not have to use hysteresis, etc. The method may use e.g. the infrared sensor for detecting sunrise and sunset, but does not have to use the incident light angle sensor, etc. This can result in different embodiments of the method, from the simplest to the most complex, wherein the most complex variant (using continuous measurements in the visible and infrared region, time parameters, hysteresis, sunrise and sunset detection as well as driver blinding risk detection) is the most preferable. The order of the individual conditions that were presented above and that will be further illustrated in exemplary embodiments may vary in the logic of the controlling method and depends on the particular embodiment of the computational program that is stored in the control unit and performs this method. The fulfilment of the conditions for starting the individual light modes can be controlled continuously, or it can be triggered by a change in the lighting intensity that results in exceeding some of the limits of the individual ranges of the ambient lighting intensity.

[0037] Description of Drawings

[0038] A summary of the invention is further clarified using exemplary embodiments thereof, which are described with reference to the accompanying drawings, in which: fig. 1 shows a graph of the dependence of the ambient lighting intensity on time, indicating the individual intensity ranges that correspond to the individual light modes, fig. 2 shows a side view of a vehicle in the first light mode, fig. 3 shows a side view of a vehicle in the second light mode, fig. 4 shows a side view of a vehicle in the third light mode, fig. 5 shows a connection of the individual components of the system for automatically controlling the exterior lighting of a vehicle, fig. 6 shows a flow chart of the method of automatically controlling the exterior lighting of a vehicle according to the first exemplary embodiment of the invention, fig. 7 shows a flow chart of the method of automatically controlling the exterior lighting of a vehicle according to the second exemplary embodiment of the invention, and fig. 8 shows a flow chart of the method of automatically controlling the exterior lighting of a vehicle according to the third exemplary embodiment of the invention.

[0039] Exemplary Embodiments of the Invention

[0040] The invention will be further clarified by exemplary embodiments with reference to the respective drawings, wherein the method of automatically controlling the exterior lighting of a vehicle 1 is most clearly clarified by the graph of fig. 1 and also the flow charts of fig. 6, fig. 7 and fig. 8 that correspond to the three different exemplary embodiments of the invention. These exemplary embodiments will be described in more detail below.

[0041] It can be seen from the graph of fig. 1 that the lighting intensity varies during the day, wherein the highest lighting intensity of approximately 100 000 lx on a clear day is reached at noon. Conversely, the lowest values of the lighting intensity, typically around 1000 lx or less, are reached at night and early morning. During sunrise and sunset, the lighting intensity typically varies approximately in the range of 1000 to 10 000 lx. In addition to the dependence of the lighting intensity on time, this graph also indicates the individual ranges corresponding to the individual light modes as well as their lower and upper limits.

[0042] It can be seen from fig. 1 that the first range of the ambient lighting intensity (corresponding to the first light mode) is limited from above by the upper limit h of the first range of the ambient lighting intensity. The second range of the ambient lighting intensity (corresponding to the second light mode) is in turn limited from below, namely by the lower limit hd of the second range of the ambient lighting intensity. The third range of the ambient lighting intensity (corresponding to the third light mode) is then limited from below as well as from above by the lower limit hd of the third range of the ambient lighting intensity and the upper limit hh of the third range of the ambient lighting intensity. The individual ranges are generally specified in such a way that the third range of the ambient lighting intensity lies above the first range of the ambient lighting intensity and the second range of the ambient lighting intensity lies above the third range of the ambient lighting intensity.

[0043] Specifically, in all of the exemplary embodiments described below, it is true that the lower limit hd of the third range of the ambient lighting intensity is higher than the upper limit hh of the first range of the ambient lighting intensity, and the upper limit hh of the third range of the ambient lighting intensity is lower than the lower limit hd of the second range of the ambient lighting intensity. So there is a certain hysteresis, i.e., there are gaps or gray zones between the individual ranges in which there is no change in the light mode. In the exemplary embodiments mentioned below, the upper limit ih of the first range of the ambient lighting intensity is selected from the range of 500 to 3000 lx (for example 1050 lx), the lower limit hd of the third range of the ambient lighting intensity is selected from the range of 500 to 5000 lx (for example 1200 lx), the upper limit hh of the third range of the ambient lighting intensity is selected from the range of 3000 to 12000 lx(for example 6500 lx), and the lower limit hd of the second range of the ambient lighting intensity is selected from the range of 4000 to 15000 lx(for example 7000 lx).

[0044] The individual light modes that are automatically set within the method of the present invention are shown in fig. 2 to fig. 4. In the first light mode of fig. 2, at least the dipped headlights 2 and the rear marker lights 3 are on. In the second light mode of fig. 3, the daytime running lights 4 are on, wherein the dipped headlights 2 and the rear marker lights 3 are off. In the third light mode, the daytime running lights 4 and the rear marker lights 3 are on, wherein the dipped headlights 2 are off. The logic of the automatic adjustment of the exterior lighting of the vehicle 1 between the first light mode, the second light mode, and the third light mode will be explained in detail using the flow charts of fig. 6 to fig. 8.

[0045] First exemplary embodiment:

[0046] In the first exemplary embodiment, the vehicle 1 is provided with at least a light sensor 6 that senses the ambient light intensity in at least a wavelength range of that corresponds to the visible region of electromagnetic radiation, i.e., approximately in the range of 380 to 750 nm. In addition to the light sensor 6, the vehicle 1 is further provided with, for example, a speed sensor 8, a steering wheel angle sensor 9 or other sensors (e.g., a sensor of the position of the direction indicator light control levers, a hazard warning signal sensor, etc.), wherein all these sensors transmit information about the sensed environment and the state of the vehicle 1 to the control unit 5. The vehicle 1 is provided with this control unit 5, which is adapted for the evaluation of the measured values and controlling the individual lights, i.e., turning them on and off. The individual sensors are connected to the control unit 5, either directly or via other control units or subunits, wherein the connection itself is implemented for example via data wires. In some alternative embodiments of the connection, this connection is implemented as a wireless one. Furthermore, the dipped headlights 2, the rear marker lights 3, and the daytime running lights 4 are connected to the control unit 5. The individual lights are data- connected to the control unit 5, i.e., the control unit 5 does not supply electrical energy to the individual lights but transmits a switching signal to the control sub-units of the lights, which then ensure that electric current is supplied to the lights and that they are activated. The provision of electric current to the lights is well-known to a person skilled in the art and it can be solved, for example, by an assembly of switching relays, or switching semiconductor elements and switching relays.

[0047] In the first exemplary embodiment, the method of automatically controlling the exterior lighting of the vehicle 1 comprises comparing the continuously measured data from the light sensor 6 that senses the ambient light intensity in the visible region to the values of the lower and upper limits hh, hd, hh, and hd. These limits are stored in the control unit 5 memory. The control according to this first exemplary embodiment is schematically depicted in the flow chart of fig. 6.

[0048] As can be seen in fig. 6, in the first exemplary embodiment, the control unit 5 continuously receives data about the ambient lighting intensity measured by the light sensor 6. First, the control unit 5 receives the measured value of the ambient lighting intensity lx, or a signal representing the value representing the ambient lighting intensity, at a time tx. In this exemplary embodiment, the time is determined by a timestamp assigned by the control unit 5 to the received value. Subsequently, the control unit 5 compares whether the value lx is within the first range of the ambient lighting intensity, i.e., whether the value lx is lower than the upper limit hh of the first range of the ambient lighting intensity. If so, the control unit 5 evaluates whether the first light mode is active. If so, the control unit 5 waits again for the next measured value of the ambient lighting intensity lx. If the first light mode is not active, the control unit 5 evaluates whether the values lx were in the first range of the ambient lighting intensity for at least the specified time ti, i.e., whether the values lx were, for at least this time ti, lower than the upper limit hh of the first range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the first light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value ti is selected in this exemplary embodiment from the range of 1 to 10 s, for example 2 s. The evaluation using this time parameter prevents the unwanted turning on of the dipped headlights 2 when passing through a short shaded space, for example under bridges, trees, and the like.

[0049] In case the measured value of the ambient lighting intensity lx is not in the first range of the ambient lighting intensity, the control unit 5 compares whether the value lx is in the second range of the ambient lighting intensity, i.e., whether the value lx is higher than the lower limit hd of the second range of the ambient lighting intensity. If so, the control unit 5 evaluates whether the second light mode is active. If so, the control unit 5 waits again for the next measured value of the ambient lighting intensity lx. If the second light mode is not active, the control unit 5 evaluates whether the values lx were in the second range of the ambient lighting intensity for at least the specified time t2, i.e., whether the values lx were, for at least this time t2, higher than the lower limit d of the second range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the second light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value t2 is selected in this exemplary embodiment from the range of 10 to 30 s, for example 15 s. The evaluation using this time parameter prevents the unwanted turning off of the dipped headlights 2 and the rear marker lights 3 under boundary conditions with regard to maintaining safe visibility.

[0050] In case the measured value of the ambient lighting intensity lx is neither in the first range of the ambient lighting intensity nor in the second range of the ambient lighting intensity, the control unit 5 compares whether the value lx is in the third range of the ambient lighting intensity, i.e., whether the value lx is higher than the lower limit hd of the third range of the ambient lighting intensity and at the same time lower than the upper limit hh of the third range of the ambient lighting intensity. If so, the control unit 5 evaluates whether the third light mode is active. If so, the control unit 5 waits again for the next measured value of the ambient lighting intensity lx. If the third light mode is not active, the control unit 5 evaluates whether the values lx were in the third range of the ambient lighting intensity at least for the specified time ta, i.e., whether the values lx were, at least for this time ta, higher than the lower limit hd of the third range of the ambient lighting intensity and at the same time lower than the upper limit hh of the third range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the third light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. In this exemplary embodiment, the value t3 is selected from the range of 10 to 20 s, for example 12 s. The evaluation using this time parameter prevents the unwanted turning on of the rear marker lights 3 during the transition from the second light mode and also the unwanted turning off of the dipped headlights 2 during the transition from the first light mode under boundary conditions with regard to maintaining safe visibility.

[0051] In case the measured value of the ambient lighting intensity lx is neither in the first range of the ambient lighting intensity, nor in the second range of the ambient lighting intensity, nor in the third range of the ambient lighting intensity, the control unit 5 again waits for the next measured value of the ambient lighting intensity and the current light mode remains active. It is because this means that the measured value of the ambient lighting intensity lx falls within the gaps (or the so-called gray zones), which are located between the individual ranges of the ambient lighting intensity. In these cases, a change of the light mode is undesirable. This is true for the automatic operation, i.e., operation in which the exterior lighting of the vehicle 1 is already in one of the above described light modes and the control unit 5 automatically decides whether and which one of the light modes will be started. In practice, however, the automatic operation is preceded by the so-called initialization phase, where the exterior lighting of the vehicle 1 should transition from a state that does not yet correspond to any of the light modes described above, to one of these light modes. Thus, this initialization phase no longer deals with the gray zones between the individual ranges and the control unit 5 issues an instruction to start the first light mode if the ambient lighting intensity is lower than the lower limit hd of the third range of the ambient lighting intensity, wherein the instruction to start the second light mode is issued if the ambient lighting intensity is higher than the lower limit hd of the second range of the ambient lighting intensity, and wherein the instruction to start the third light mode is issued if the ambient lighting intensity is between the lower limit hd of the third range of the ambient lighting intensity and the lower limit d of the second range of the ambient lighting intensity.

[0052] Second exemplary embodiment: In the second exemplary embodiment, the vehicle 1 is provided with at least the light sensor 6 that senses the ambient light intensity in at least a wavelength range that corresponds to the visible region of electromagnetic radiation, i.e., approximately in the range of 380 to 750 nm, and furthermore at least in a wavelength range that corresponds to the infrared region of electromagnetic radiation, i.e., approximately in the range of 760 nm to 1 mm. The measurement of the ambient lighting intensity in the infrared region is used to detect sunrise or sunset, as will be described below. In addition to the light sensor 6, the vehicle 1 is further provided with, for example, a speed sensor 8, a steering wheel angle sensor 9 or other sensors (e.g., a sensor of the position of the direction indicator light control levers, a hazard warning signal sensor, etc.), wherein all these sensors transmit information about the sensed environment and the state of the vehicle 1 to the control unit 5. The vehicle 1 is provided with this control unit 5, which is adapted for the evaluation of the measured values and controlling the individual lights, i.e., turning them on and off. The individual sensors are connected to the control unit 5, either directly or via other control units or sub-units, wherein the connection itself is implemented for example via data wires. In some alternative embodiments of the connection, this connection is implemented as a wireless one. Furthermore, the dipped headlights 2, the rear marker lights 3, and the daytime running lights 4 are connected to the control unit 5. The individual lights are data-connected to the control unit 5, i.e., the control unit 5 does not supply electrical energy to the individual lights but transmits a switching signal to the control sub-units of the lights, which then ensure that electric current is supplied to the lights and that they are activated. The provision of electric current to the lights is well- known to a person skilled in the art and it can be solved, for example, by an assembly of switching relays, or switching semiconductor elements and switching relays.

[0053] In the second exemplary embodiment, the method of automatically controlling the exterior lighting of the vehicle 1 comprises comparing the continuously measured data from the light sensor 6 that senses the ambient light intensity in the visible region and in the infrared region to the values of the lower and upper limits hh, hd, hh, and hd. These limits are stored in the control unit 5 memory. The control according to this second exemplary embodiment is schematically depicted in the flow chart of fig. 7.

[0054] As can be seen in fig. 7, in the second exemplary embodiment, the control unit 5 continuously receives data about the ambient lighting intensity measured by the light sensor 6 in the visible region. First, the control unit 5 receives the measured value of the ambient lighting intensity lx, or a signal representing the value representing the ambient lighting intensity, at a time tx. In this exemplary embodiment, the time is determined by a timestamp assigned by the control unit 5 to the received value. Subsequently, the control unit 5 compares whether the value lx is within the first range of the ambient lighting intensity, i.e., whether the value lx is lower than the upper limit hh of the first range of the ambient lighting intensity. If so, the control unit 5 evaluates whether the first light mode is active. If so, the control unit 5 waits again for the next measured value of the ambient lighting intensity lx. If the first light mode is not active, the control unit 5 evaluates whether the values lx were in the first range of the ambient lighting intensity at least for the specified time ti, i.e., whether the values lx were, at least for this time ti, lower than the upper limit hh of the first range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the first light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value ti is selected in this exemplary embodiment from the range of 1 to 10 s, for example 2 s. The evaluation using this time parameter prevents the unwanted turning on of the dipped headlights 2 when passing through a short shaded space, for example under bridges, trees, and the like.

[0055] In case the measured value of the ambient lighting intensity lx is not in the first range of the ambient lighting intensity, the control unit 5 compares whether the value lx is in the second range of the ambient lighting intensity, i.e., whether the value lx is higher than the lower limit hd of the second range of the ambient lighting intensity. If so, the control unit 5 evaluates whether sunrise or sunset is detected. Sunrise or sunset is detected by measuring the ambient lighting intensity in a wavelength range that corresponds to the infrared region, i.e., approximately in the range of 760 nm to 1 mm. This is made possible by the fact that sunrise or sunset are identically characterized by an increased intensity in the region of red, and especially also infrared light. For example, sunrise or sunset is detected using the specified boundary of the ambient lighting intensity for one or multiple wavelengths from the infrared region. This boundary is stored in the control unit 5. If the measured intensity is higher than this specified boundary, the control unit 5 evaluates that sunrise or sunset is occurring.

[0056] If sunrise or sunset is detected, the control unit 5 evaluates whether the values lx were in the second range of the ambient lighting intensity at least for the specified time t3, i.e., whether the values lx were, at least for this time ta, higher than the lower limit lad of the second range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the third light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value t3 is selected in this exemplary embodiment from the range of 10 to 20 s, for example 12 s. The evaluation using this time parameter prevents the unwanted turning on of the rear marker lights 3 under boundary conditions with regard to maintaining safe visibility.

[0057] If sunrise or sunset is not detected, the control unit 5 evaluates whether the values lx were in the second range of the ambient lighting intensity at least for the specified time t2, i.e., whether the values lx were, at least for this time t2, higher than the lower limit d of the second range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the second light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value t2 is selected in this exemplary embodiment from the range of 10 to 30 s, for example 15 s. The evaluation using this time parameter prevents the unwanted turning off of the dipped headlights 2 and the rear marker lights 3 under boundary conditions with regard to maintaining safe visibility.

[0058] In case the measured value of the ambient lighting intensity lx is neither in the first range of the ambient lighting intensity nor in the second range of the ambient lighting intensity, the control unit 5 compares whether the value lx is in the third range of the ambient lighting intensity, i.e., whether the value lx is higher than the lower limit hd of the third range of the ambient lighting intensity and at the same time lower than the upper limit hh of the third range of the ambient lighting intensity. If so, the control unit 5 evaluates whether the third light mode is active. If so, the control unit 5 waits again for the next measured value of the ambient lighting intensity lx. If the third light mode is not active, the control unit 5 evaluates whether the values lx were in the third range of the ambient lighting intensity at least for the specified time t3, i.e., whether the values lx were, at least for this time t3, higher than the lower limit hd of the third range of the ambient lighting intensity and at the same time lower than the upper limit hh of the third range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the third light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity.

[0059] In case the measured value of the ambient lighting intensity lx is neither in the first range of the ambient lighting intensity, nor in the second range of the ambient lighting intensity, nor in the third range of the ambient lighting intensity, the control unit 5 again waits for the next measured value of the ambient lighting intensity and the current light mode remains active. It is because it means that the measured value of the ambient lighting intensity lx falls within the gaps (or the so-called gray zones), which are located between the individual ranges of the ambient lighting intensity. In these cases, a change of the light mode is undesirable. This is true for automatic operation, i.e., operation in which the exterior lighting of the vehicle 1 is already in one of the above described light modes and the control unit 5 automatically decides whether and which one of the light modes will be started. In practice, however, the automatic operation is preceded by a so- called initialization phase, where the exterior lighting of the vehicle 1 should transition from a state that does not yet correspond to any of the light modes described above, to one of these light modes. Thus, this initialization phase no longer deals with gray zones between the individual ranges and the control unit 5 issues an instruction to start the first light mode if the ambient lighting intensity is lower than the lower limit hd of the third range of the ambient lighting intensity, wherein the instruction to start the second light mode is issued if the ambient lighting intensity is higher than the lower limit hd of the second range of the ambient lighting intensity, and wherein the instruction to start the third light mode is issued if the ambient lighting intensity is between the lower limit hd of the third range of the ambient lighting intensity and the lower limit 2d of the second range of the ambient lighting intensity.

[0060] Third exemplary embodiment:

[0061] In the third exemplary embodiment, the vehicle 1 is provided with at least the light sensor 6 that senses the ambient light intensity in at least a wavelength range that corresponds to the visible region of electromagnetic radiation, i.e., approximately in the range of 380 to 750 nm, and furthermore at least in a wavelength range that corresponds to the infrared region of electromagnetic radiation, i.e., approximately in the range of 760 nm to 1 mm. The measurement of the ambient lighting intensity in the infrared region is used to detect sunrise or sunset, as will be described below. The vehicle 1 is further provided with an incident light angle sensor 7 that senses at what angles the light is incident relative to the vertical plane. By measuring the incident light angle relative to the vertical plane, it can be determined whether the vehicle 1 is driving against the rising or setting sun, and therefore, whether or not there is a risk of blinding the driver. In addition to the light sensor 6 and the incident light angle sensor 7, the vehicle 1 is further provided with, for example, the speed sensor 8, the steering wheel angle sensor 9, or other sensors (e.g., a sensor of the position of the direction indicator light control levers, a hazard warning signal sensor, etc.), wherein all these sensors transmit information about the sensed environment and the state of the vehicle 1 to the control unit 5. The vehicle 1 is provided with this control unit 5, which is adapted for the evaluation of the measured values and controlling the individual lights, i.e., turning them on and off. The individual sensors are connected to the control unit 5, either directly or via other control units or subunits, wherein the connection itself is implemented for example via data wires. In some alternative embodiments of the connection, this connection is implemented as a wireless one. Furthermore, the dipped headlights 2, the rear marker lights 3, and the daytime running lights 4 are connected to the control unit 5. The individual lights are data- connected to the control unit 5, i.e., the control unit 5 does not supply electrical energy to the individual lights but transmits a switching signal to the control sub-units of the lights, which then ensure that electric current is supplied to the lights and that they are activated. The provision of electric current to the lights is well-known to a person skilled in the art and it can be solved, for example, by an assembly of switching relays, or switching semiconductor elements and switching relays.

[0062] In the third exemplary embodiment, the method of automatically controlling the exterior lighting of the vehicle 1 comprises comparing the continuously measured data from the light sensor 6 that senses the ambient light intensity in the visible region and in the infrared region to the values of the lower and upper limits hh, hd, hh, and hd and also using the incident light angle sensor 7. Said limits are stored in the memory of the control unit 5. The control according to this third exemplary embodiment is schematically depicted in the flow chart of fig. 8.

[0063] As can be seen in fig. 8, in the third exemplary embodiment, the control unit 5 continuously receives data about the ambient lighting intensity measured by the light sensor 6 in the visible region. First, the control unit 5 receives the measured value of the ambient lighting intensity lx, or a signal representing the value representing the ambient lighting intensity, at a time tx. In this exemplary embodiment, the time is determined by a timestamp assigned by the control unit 5 to the received value. Subsequently, the control unit 5 compares whether the value lx is within the first range of the ambient lighting intensity, i.e., whether the value lx is lower than the upper limit hh of the first range of the ambient lighting intensity. If so, the control unit 5 evaluates whether the first light mode is active. If so, the control unit 5 waits again for the next measured value of the ambient lighting intensity lx. If the first light mode is not active, the control unit 5 evaluates whether the values lx were in the first range of the ambient lighting intensity at least for the specified time ti, i.e., whether the values lx were, at least for this time ti, lower than the upper limit h of the first range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the first light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value ti is selected in this exemplary embodiment from the range of 1 to 10 s, for example 2 s. The evaluation using this time parameter prevents the unwanted turning on of the dipped headlights 2 when passing through a short shaded space, for example under bridges, trees, and the like.

[0064] In case the measured value of the ambient lighting intensity lx is not in the first range of the ambient lighting intensity, the control unit 5 compares whether the value lx is in the second range of the ambient lighting intensity, i.e., whether the value lx is higher than the lower limit hd of the second range of the ambient lighting intensity. If so, the control unit 5 evaluates whether sunrise or sunset is detected. Sunrise or sunset is detected by measuring the ambient lighting intensity in a wavelength range that corresponds to the infrared region, i.e., approximately in the range of 760 nm to 1 mm. This is made possible by the fact that sunrise or sunset are identically characterized by an increased intensity in the region of red, and especially also infrared light. For example, sunrise or sunset is detected using the specified boundary of the ambient lighting intensity for one or multiple wavelengths from the infrared region. This boundary is stored in the control unit 5. If the measured intensity is higher than this specified boundary, the control unit 5 evaluates that sunrise or sunset is occurring.

[0065] If sunrise or sunset is detected, the control unit 5 evaluates whether there is a risk of blinding the driver. The risk of blinding the driver is detected by measuring the incident light angle relative to the vertical plane using the incident light angle sensor 7. For example, the risk of blinding the driver is detected using the specified range of the incident light angle relative to the vertical plane. This range is stored in the control unit 5. For example, this range is specified as 30 to 150°, measured relative to the vertical plane which is oriented in the transverse direction of the vehicle, or, in other words, perpendicular to the direction of travel of the vehicle T The angle means an angle that takes values of 0 to 180° in the front horizontal half-plane relative to the direction of travel and values of 180 to 360° in the rear horizontal half-plane relative to the direction of travel. If the measured incident light angle is within the specified range, the control unit 5 evaluates that there is a risk of blinding the driver as the vehicle 1 is driving against the setting or rising sun. In such a case, the control unit 5 evaluates whether the values lx were in the second range of the ambient lighting intensity for at least the specified time t3, i.e., whether the values lx were, for at least this time ta, higher than the lower limit lad of the second range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the third light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value t3 is selected in this exemplary embodiment from the range of 10 to 20 s, for example 12 s. The evaluation using this time parameter prevents the unwanted turning on of the rear marker lights 3 under boundary conditions with regard to maintaining safe visibility. If the measured incident light angle is not within the specified range, the control unit 5 evaluates that there is no risk of blinding the driver because the vehicle 1 is not driving against the setting or rising sun. In such case, the control unit 5 evaluates whether the values lx were in the second range at least for the specified time t2, i.e., whether the values lx were, at least for this time t2, higher than the lower limit kd of the second range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the second light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity. The value t2 is selected in this exemplary embodiment from the range of 10 to 30 s, for example 15 s. The evaluation using this time parameter prevents the unwanted turning off of the dipped headlights 2 and the rear marker lights 3 under boundary conditions with regard to maintaining safe visibility.

[0066] If sunrise or sunset is not detected, the control unit 5 evaluates whether the values lx were in the second range of the ambient lighting intensity at least for the specified time t2, i.e., whether the values lx were, at least for this time t2, higher than the lower limit l2d of the second range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the second light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity.

[0067] In case the measured value of the ambient lighting intensity lx is neither in the first range of the ambient lighting intensity nor in the second range of the ambient lighting intensity, the control unit 5 compares whether the value lx is in the third range of the ambient lighting intensity, i.e., whether the value lx is higher than the lower limit hd of the third range of the ambient lighting intensity and at the same time lower than the upper limit hh of the third range of the ambient lighting intensity. If so, the control unit 5 evaluates whether the third light mode is active. If so, the control unit 5 waits again for the next measured value of the ambient lighting intensity lx. If the third light mode is not active, the control unit 5 evaluates whether the values lx were in the third range of the ambient lighting intensity at least for the specified time ta, i.e., whether the values lx were, at least for this time ta, higher than the lower limit hd of the third range of the ambient lighting intensity and at the same time lower than the upper limit hh of the third range of the ambient lighting intensity. If they were, the control unit 5 issues an instruction to start the third light mode. If they were not, the control unit 5 waits again for the next measured value of the ambient lighting intensity.

[0068] In case the measured value of the ambient lighting intensity lx is neither in the first range of the ambient lighting intensity, nor in the second range of the ambient lighting intensity, nor in the third range of the ambient lighting intensity, the control unit 5 again waits for the next measured value of the ambient lighting intensity and the current light mode remains active. It is because it means that the measured value of the ambient lighting intensity lx falls within the gaps (or the so-called gray zones), which are located between the individual ranges of the ambient lighting intensity. In these cases, a change of the light mode is undesirable. This is true for automatic operation, i.e., operation in which the exterior lighting of the vehicle 1 is already in one of the above described light modes and the control unit 5 automatically decides whether and which one of the light modes will be started. In practice, however, the automatic operation is preceded by a so- called initialization phase, where the exterior lighting of the vehicle 1 should transition from a state that does not yet correspond to any of the light modes described above, to one of these light modes. Thus, this initialization phase no longer deals with gray zones between the individual ranges and the control unit 5 issues an instruction to start the first light mode if the ambient lighting intensity is lower than the lower limit hd of the third range of the ambient lighting intensity, wherein the instruction to start the second light mode is issued if the ambient lighting intensity is higher than the lower limit hd of the second range of the ambient lighting intensity, and wherein the instruction to start the third light mode is issued if the ambient lighting intensity is between the lower limit hd of the third range of the ambient lighting intensity and the lower limit 2d of the second range of the ambient lighting intensity. Beyond these three exemplary embodiments, the method of automatic control may be implemented in other alternative embodiments, wherein possible alternatives are outlined in more detail in the section Summary of the invention. In some alternative embodiments, e.g., the individual conditions described using the diagrams of fig. 6 to fig. 8, are implemented in a different order depending on the particular embodiment of the computational program that is stored in the control unit and that performs this method.

[0069] List of Reference Signs

[0070] 1 - vehicle

[0071] 2 - dipped headlights

[0072] 3 - rear marker lights

[0073] 4 - daytime running lights

[0074] 5 - control unit

[0075] 6 - light sensor

[0076] 7 - incident light angle sensor

[0077] 8 - speed sensor

[0078] 9 - steering wheel angle sensor

Claims

CLAIMS1. A method of automatically controlling exterior lighting of a vehicle (1 ) comprising an automatic adjustment of exterior lighting of the vehicle (1 ) between a first light mode, a second light mode, and a third light mode based on ambient lighting intensity information, wherein in the first light mode, at least dipped headlights (2) and rear marker lights (3) are on, and in the second light mode, daytime running lights (4) are on, wherein the dipped headlights (2) and the rear marker lights (3) are off in the second light mode, characterized in that this method comprises the steps of:- comparing the ambient lighting intensity measured by at least one light sensor (8) with a specified first range of the ambient lighting intensity, a second range of the ambient lighting intensity, and a third range of the ambient lighting intensity using a control unit (5), wherein the third range of the ambient lighting intensity lies above the first range of the ambient lighting intensity and the second range of the ambient lighting intensity lies above the third range of the ambient lighting intensity,- issuing an instruction to start the first light mode by the control unit (5) if the ambient lighting intensity is in the specified first range of the ambient lighting intensity,- issuing an instruction to start the second light mode by the control unit (5) if the ambient lighting intensity is in the specified second range of the ambient lighting intensity, and- issuing an instruction to start the third light mode by the control unit (5) if the ambient lighting intensity is in the specified third range of the ambient lighting intensity, wherein in the third light mode, the daytime running lights (4) and the rear marker lights (3) are on, wherein the dipped headlights (2) are off in the third light mode.

2. The method of automatically controlling the exterior lighting of the vehicle (1 ) according to claim 1 , characterized in that the comparison is based on input data,which are obtained by a continuous measurement of the ambient lighting intensity by the at least one light sensor (8) in at least a wavelength range that corresponds to the visible region of electromagnetic radiation.

3. The method of automatically controlling the exterior lighting of the vehicle (1 ) according to any one of claims 1 to 2, characterized in that the lower limit hd of the third range of the ambient lighting intensity is higher than the upper limit h of the first range of the ambient lighting intensity, and the upper limit hh of the third range of the ambient lighting intensity is lower than the lower limit hd of the second range of the ambient lighting intensity.

4. The method of automatically controlling the exterior lighting of the vehicle (1 ) according to any one of claims 1 to 3, characterized in that the step of issuing an instruction to start the first light mode by the control unit (5) is performed if the ambient lighting intensity is within the first range of the ambient lighting intensity for at least a specified time t-i, the step of issuing an instruction to start the second light mode by the control unit (5) is performed if the ambient lighting intensity is in the second range of the ambient lighting intensity for at least a specified time t2, and the step of issuing an instruction to start the third light mode by the control unit (5) is performed if the ambient lighting intensity is in the third range of the ambient lighting intensity for at least a specified time t3.

5. The method of automatically controlling the exterior lighting of the vehicle (1 ) according to any one of claims 1 to 4, characterized in that the step of issuing an instruction to start the third light mode by the control unit (5) is performed if the ambient lighting intensity is in the second range of the ambient lighting intensity and sunrise or sunset is detected at the same time.

6. The method of automatically controlling the exterior lighting of the vehicle (1 ) according to claim 5, characterized in that sunrise or sunset is detected by measuring the ambient lighting intensity in a wavelength range that corresponds to the infrared region of electromagnetic radiation.

7. The method of automatically controlling the exterior lighting of the vehicle (1 ) according to any one of claims 5 to 6, characterized in that if sunrise or sunset is detected, it is determined whether there is a risk of blinding the driver by measuringthe incident light angle relative to the vertical plane using the incident light angle sensor (7), wherein if it is determined that there is no risk of blinding the driver, the step of issuing an instruction to start the second light mode is performed by the control unit (5).

Images