Method for controlling a headlight system of a motor vehicle and controller and device for carrying out the method

Abstract

A method and apparatus for controlling a headlight system of a motor vehicle is disclosed. The headlight system can be actuated in at least two control modes, each having an associated, predetermined maximum main beam width. First, a current driving situation of the motor vehicle is captured on the basis of at least one operating, parameter of the motor vehicle. A current control mode is ascertained based on which control mode from at least two control modes matches a control mode assigned to the captured driving situation on the basis of the captured current driving situation and at least one-time or temporal parameter. The controller is shifted into the assigned control mode when the current control mode does not match the assigned control mode, wherein a maximum main beam width is set for the current driving situation.

Claims

1. A method for controlling a headlight system of a motor vehicle, which can be actuated in at least two control modes, the method comprising: assigning a driving status to each of at least two control modes, wherein each control mode has a predetermined maximum main beam width associated therewith; capturing a current driving situation of the motor vehicle on the basis of at least one operating parameter measured locally at the motor vehicle; ascertaining when a current control mode matches one of the least two control modes on the basis of the captured current driving situation and at least one temporal parameter; and automatically shifting the headlight system into the assigned control mode when the current control mode does not match the assigned control mode so that the predetermined maximum main beam width is adapted to the current driving situation.

2. The method according to claim 1, wherein the at least one operating parameter comprises a current motor vehicle speed, and wherein the at least one temporal parameter comprises a current status of a timer.

3. The method according to claim 2, wherein the at least one operating parameter further comprises a current bend radius, and the method further comprises shifting the headlight system from a base mode having a maximum main beam width into a first motorway mode having a first maximum main beam width that is less than the maximum main beam width of the base mode when the current motor vehicle speed exceeds a first predefined speed threshold and the current bend radius exceeds a first predefined bend radius threshold, each continuously for a first predefined time period.

4. The method according to claim 3, wherein the method further comprises shifting the headlight system from the first motorway mode back into the base mode when in the first motorway mode the current motor vehicle speed falls below a fourth predefined speed threshold or the current bend radius falls below a fourth predefined bend radius threshold continuously for a fourth predefined time period.

5. The method according to claim 3, wherein the method further comprises shifting the headlight system the first motorway mode to a second motorway mode, having a second maximum main beam width that is less than the maximum main beam width of the base mode to avoid dazzling oncoming motor vehicles when the current motor vehicle speed exceeds a second predefined speed threshold and the current bend radius exceeds a second predefined bend radius threshold, each continuously for a second predefined time period.

6. The method according to claim 5, wherein the method further comprises: capturing a current traffic density; and shifting the headlight system into a third motorway mode with the maximum main beam width of the base mode when the current motor vehicle speed exceeds a third predefined speed threshold and the current traffic density falls below a predefined maximum traffic density.

7. The method according to claim 5, wherein the method further comprises shifting the headlight system from the second motorway mode back into the first motorway mode when the current motor vehicle speed falls below a fifth predefined speed threshold or the current bend radius falls below the fifth predefined bend radius threshold for a fifth predefined time period.

8. The method according to claim 7 wherein the method further comprises shifting the headlight system into the first motorway mode without consideration for the current timer status when the motor vehicle speed exceeds a preset gear changing speed.

9. A controller for a headlight system in a motor vehicle, comprising: a receiver interface for receiving data that represents information about a current driving situation of the motor vehicle measured locally at the motor vehicle; a timer configured to provide a current timer status; an evaluation unit configured to determine whether a current control mode matches a control mode from at least two control modes assigned to the captured driving status, each control mode having a predetermined maximum main beam width associated therewith on the basis of the received data and the current timer status; and an output interface for outputting signals to a headlight control unit; wherein the evaluation unit is configured to command the output interface to send signals to the headlight control unit for shifting the headlight control unit into a control mode having a maximum main beam width adapted to the current driving situation.

10. The controller according to claim 9 further comprising a sensor device for locally capturing a driving situation of the motor vehicle, and a headlight control unit connected to the sensor device for controlling a headlight system.

11. The controller according to claim 9, wherein the receiver interface is configured to receive data representing information about a current environment of the motor vehicle, and wherein the evaluation unit is configured to calculate a current traffic density using said information based on a number of oncoming motor vehicles within a predefined time period, and to command the output interface to send signals to the headlight control unit for shifting the headlight control unit into a control mode having a maximum main beam width adapted to the current driving situation and the current traffic density.

12. A motor vehicle comprising a controller according to claim 11 having a sensor device connected to at least one sensor of the motor vehicle, and a headlight control unit connected to a headlight system of the motor vehicle.

13. The motor vehicle according to claim 12, wherein the headlight system comprises at least one LED matrix headlight with a plurality of LEDs and the controller is configured to actuate the plurality of LEDs individually or in a cluster.

14. A non-transitory computer accessible storage medium, having instructions stored therein for controlling a headlight system of a motor vehicle which can be actuated with at least two control modes, each having an associated, predetermined maximum main beam width, wherein the instructions stored in the non-transitory computer accessible storage medium, when executed on a computing unit in the motor vehicle, instructs the computing unit to: capture a current driving situation of the motor vehicle on the basis of at least one operating parameter of the motor vehicle measured locally at the motor vehicle; ascertain whether a current control mode matches the control mode of the least two control modes assigned to the captured driving status on the basis of the captured current driving situation and at least one temporal parameter; and shift the controller into the assigned control mode when the current control mode does not match the assigned control mode, so that a maximum main beam width adapted to the current driving situation can be set.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements.

(2) FIG. 1 is a diagrammatic representation of an overtaking maneuver, with one vehicle overtaking and one vehicle being overtaken, intended to explain how dazzle in the mirror occurs;

(3) FIG. 2 is a diagrammatic representation of the overtaking maneuver of FIG. 1, using the method according to an embodiment of the present disclosure;

(4) FIG. 3 is a diagrammatic representation of a motorway scenario with carriageways separated by structural elements in order to illustrate an embodiment of the present disclosure;

(5) FIG. 4 shows a flowchart of an embodiment of a method according to the present disclosure; and

(6) FIG. 5 shows a device for controlling a headlight control system of a motor vehicle according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

(7) The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.

(8) FIG. 1 is a diagrammatic representation of an overtaking maneuver, with one vehicle overtaking and one vehicle being overtaken, intended to explain how dazzle in the mirror occurs. First, FIG. 1 serves to explain how mirror dazzle occurs during an overtaking maneuver, if a method for preventing dazzle according to one of the aspects of the present disclosure is not implemented. A motor vehicle being overtaken 1 and an overtaking vehicle 2 with headlights 10 and taillights 8 are shown.

(9) In this example, the headlights 10 of the motor vehicle being overtaken 1 are LED matrix headlights with individually actuatable elements. Headlights 10 have a main beam distribution which is described by a light cone. A light cone 4 of a main beam emitted by the LED matrix headlights 10 of motor vehicle 1 is represented diagrammatically by two solid lines. Light cone 4 has a cone angle b.sub.0 that corresponds to a min beam width of LED matrix headlights 10, and in this example is equal to about +/20.

(10) Motor vehicle 1 has an environment sensor in the frontal area thereof for the purpose of capturing the surrounding area, and which has the form of a camera 5. A detection range 6 of camera 5 is expressed by a camera cone angle a. Detection range 6 of the camera is represented diagrammatically in FIG. 1 by two dashed lines. Angle a is smaller than the width of main beam b.sub.0, and has a value of about +/19. Thus, the detection range 6 of camera 5 lies entirely within light cone 4 of the main beam. Camera 5 is designed such that overtaking vehicles can be detected by their taillights. It is therefore not possible to recognize overtaking vehicle 2 as such until at least one of the taillights 8 of overtaking vehicle 2 passes into camera detection range 6.

(11) In the phase of the overtaking maneuver illustrated in FIG. 1, part of motor vehicle 2 is captured in light cone 4. The right wing mirror 7 of vehicle 2 is already within light cone 4 and is thus in the dazzle area of the main beam of headlights 10 of the vehicle being overtaken 1. Camera 5 is not able to detect the taillights 8 of overtaking vehicle 2. A controlling system for an automatic headlight dipping system present in vehicle 1 cannot respond when vehicle 2 enters the dazzle area of vehicle 1, because vehicle 2 is not detected by camera 5, and consequently remains invisible to the controlling system in vehicle 1. In this constellation, it is possible that the driver of vehicle 2 may be dazzled via the right wing mirror, which is symbolized in FIG. 1 with a schematic representation of an explosion 9.

(12) In the event of such dazzling via the mirror, the driver of overtaking motor vehicle 2 may be dazzled briefly by the wing mirror 7 on vehicle 2. This dazzling effect lasts for less than a second or few seconds. However, dazzling effects may be longer lasting or may be repetitive, in traffic travelling in parallel lanes, when vehicles 1 and 2 are travelling at approximately the same speed, and the configuration shown in FIG. 1 persists for a longer period or recurs repeatedly.

(13) However, dazzling via the mirror can be prevented through a reduced main beam width by implementing the method according to an embodiment of the present disclosure in a main beam width headlight control mode provided in the method.

(14) FIG. 2 is a diagrammatic representation of the overtaking maneuver of FIG. 1 with a reduced main beam width. In this example, motor vehicle 1 is equipped with a device for carrying out the method according to an embodiment of the present disclosure. By appropriate reduction of the main beam width to a predefined main beam width b.sub.1 the right taillight 8 of the overtaking vehicle 2 is detected by camera 5 in the vehicle being overtaken 1, without the right wing mirror 7 of vehicle 2 passing into the main beam light cone 4 of vehicle 1. The main beam width is indicated in FIG. 2 by cone angle b1. In such case, the main beam distribution has been modified asymmetrically in such manner that essentially only the left side of the light distribution of LED matrix headlights 10 is limited by a deactivation of corresponding segments of the LED matrix headlights. The right side of the main beam distribution largely corresponds to the main beam distribution of FIG. 1, which is not limited or reduced, so that full lighting performance is maintained in the distribution of light on the right-hand side.

(15) FIG. 3 is a diagrammatic representation of a motorway scenario with carriageways separated by structural elements in order to illustrate another embodiment of the present disclosure. The figure shows a motor vehicle 1 travelling on a motorway, and a vehicle 3 travelling in the opposite direction to vehicle 1. The headlights 10 of the vehicles are also shown. Motor vehicle 1 has a built-in camera 5 and corresponds to the vehicle 1 of FIG. 1, wherein the headlights 10 of vehicle 1 can be actuated according to a method according to one of the aspects of the present disclosure.

(16) The motorway represented in FIG. 3 has carriageways separated by structural elements, with a visibility barrier 11 between the carriageways for traffic travelling in opposite directions. Because of the visibility barrier 11, the headlights 10 of oncoming motor vehicles 3 are not detected, or not detected in time, by the camera 5 built into vehicle 1. Consequently, the automatic headlight dipping system present in vehicle 1 cannot be activated in time to avoid dazzling the approaching motor vehicle 3.

(17) In a control mode according to one embodiment of the present disclosure, the dazzle effect on oncoming vehicles is reliably suppressed even in the presence of such visibility barriers by suit-able reduction of the main beam width. FIG. 3 shows two different cone angles of light cone 4 of the main beam from motor vehicle 1. Cone angle b.sub.0 corresponds to a full, maximum main beam width of headlights 10, with no reduction according to any of the control modes provided in the method. On the other hand, cone angle b.sub.2 corresponds to a main beam width that has been limited according to a control mode. In this control mode, in this case the second motorway mode, the main beam with main beam width b.sub.2 is essentially limited to the right half of the illumination area. In this way, oncoming traffic is not exposed to dazzle effects even if it is not detected by the environment sensor in motor vehicle 1.

(18) FIG. 4 shows a flowchart of an embodiment of the method according to the present disclosure for controlling a motor vehicle's headlight system. The vehicle in this example corresponds to the motor vehicle 1 of FIGS. 1 to 3, and is designed in such manner that the method for controlling the headlight system can be carried out. The headlight system can be actuated with various control modes (100, 111, 121, 131), each of which has an associated, predetermined maximum main beam width (b.sub.0, b.sub.1, b.sub.2). The flowchart illustrates for exemplary purposes the criteria that are considered before the system switches from one control mode to another control mode. According to the method represented, a current driving situation is captured on the basis of the at least one operating parameter of motor vehicle 1. In this example, a current vehicle speed v.sub.F and a current turning or bend radius r.sub.F are used as operating parameters for capturing the current driving situation. In one of the query steps (110, 115, 120, 125, 130, 135). It is determined on the basis of the captured current driving situation and the at least on time or temporal parameter whether a current control mode (100, 111, 121, 131) matches a control mode assigned to the captured driving status. In this context a current timer status t.sub.F serves as the time or temporal parameter. If it is determined in the course of any of the query steps (110, 115, 120, 125, 130, 135) that the current control mode does not match a control mode (100, 111, 121, 131) assigned to the current driving situation, the controller is switched to the assigned control mode, so that a maximum main beam width adapted to the current driving situation may be set.

(19) In a base mode 100 having a maximum main beam width b.sub.0, in a first step 100 it is determined whether the prerequisite conditions for carrying out further queries according to the embodiment are satisfied. This is the case when the current vehicle speed exceeds a minimum speed v.sub.min. In this example, minimum speed v.sub.min has a value of 100 kph. This speed corresponds to a moderate motorway driving speed, so that a vehicle travelling at this speed might already be located on a fast road or a motorway. In base mode 100, full use is made of the main beam width, i.e., the maximum main beam width b.sub.0 in base mode 100 corresponds to the full main beam, with no limitation by any suppressing functions on headlight system 52.

(20) If the minimum speed v.sub.min is exceeded in base mode 100, it is ascertained in query step 110 whether the current vehicle speed v.sub.F exceeds a first predefined speed threshold v.sub.1 and the current bend radius r.sub.F exceeds a first predefined bend radius threshold r.sub.1, each continuously for a first predefined minimum time period t.sub.1, in other words whether v.sub.F>v.sub.1 and r.sub.F>r.sub.1 for t.sub.F>t.sub.1. In this case, controller is switched from base mode 100 into a first motorway mode 111 with a first maximum main beam width b.sub.1 that is limited compared to the maximum main beam width of base mode b.sub.0 in order to avoid dazzling a motor vehicle 2 ahead of the first vehicle via its mirrors. In this example, first speed threshold v.sub.1 is 114 kph, t.sub.1 is 2 min, and bend radius threshold r.sub.1 is 425 m, which corresponds to a minimum radius of motorway bends that is widely standardized in Europe. These parameters may be modified to reflect both different countries and different terrains. If bend radius threshold r.sub.1 or speed threshold v.sub.1 is exceeded only for a short time, but these values subsequently fall to levels below these threshold values before the status of timer t.sub.F reaches minimum time t.sub.1, the timer is reset so that counting of the timer status t.sub.F can begin from zero again the next time the threshold values v.sub.1 and r.sub.1 are exceeded, and the headlight controller remains in base mode as long as the prerequisite conditions of method step 110 are not satisfied. Only when the condition v.sub.F>v.sub.1 and r.sub.F>r.sub.1 is fulfilled for the entire time period t.sub.1 is the controller switched from base mode 100 to first motorway mode 111 by the controller.

(21) When first motorway mode 111 is accessed, the main beam distribution is limited in such a way that the traffic ahead of the vehicle in question is not dazzled by the main beam. In this context, the two outer segments of the left illumination area are suppressed by deactivation of the corresponding areas in the LED matrix, so that a motor vehicle travelling ahead is captured by camera 5 before the right wing mirror 7 of motor vehicle 2 passes into light cone 4 (see also FIG. 2). After switching to the first motorway mode 111 in a next query step 120 it is ascertained whether the current vehicle speed v.sub.F has exceeded a second predefined speed threshold v.sub.2 and the current bend radius r.sub.F has exceeded a second predefined bend radius threshold r.sub.2, each continuously for a second predefined time period t.sub.2. If this condition is satisfied, the controller is shifted from the first motorway mode 111 to a second motorway mode 121 with a second maximum main beam width b.sub.2 which is limited compared with the maximum main beam width of base mode b.sub.0 in order to avoid dazzling oncoming motor vehicles 3. The threshold values for v.sub.2 may be 10-20% higher than v.sub.1, and r.sub.2 may be equal to or greater than r.sub.1. These threshold values correspond to a higher motorway speed or a higher motorway category. In this example, threshold value v.sub.2 is in the order of 130 kph, while r.sub.2=r.sub.1=425 m.

(22) After switching to the second motorway mode 121, the main beam distribution is limited still further, so that drivers of oncoming vehicles are not dazzled by the main beam. In this context, more segments of the left illumination area are suppressed by deactivation of the corresponding areas in the LED matrix, so that an oncoming vehicle is not caught in light cone 4 (see also FIG. 3). In this embodiment, therefore, b.sub.2<b.sub.1. And in the second motorway mode, the entire left half of the main beam distribution is essentially suppressed.

(23) In the embodiment according to FIG. 4, a current traffic density is also detected, and in the second motorway mode it is ascertained in query step 130 whether the current vehicle speed v.sub.F exceeds a third predefined speed threshold v.sub.3 and whether the current traffic density falls below a predefined maximum traffic density. In this case, the controller is switched to a third motorway mode 131. In this context, the current traffic density is defined according to a number of oncoming vehicles per unit of time. The predefined maximum traffic density is defined as a predetermined maximum number of oncoming motor vehicles n.sub.max within a third predetermined time period t.sub.3.

(24) In the third motorway mode 131, the maximum main beam width is equal to b.sub.0, which means that the full extent of the main beam width is used, just as in base mode 100. In a query step 115 in first motorway mode 111 it is ascertained whether the current vehicle speed v.sub.F falls below a fourth predefined speed threshold v.sub.4 or the current bend radius r.sub.F falls below a fourth predefined bend radius threshold r.sub.4 continuously for a fourth predefined time period t.sub.4. In this case, the controller is shifted back in to base mode 100 from first motorway mode 111. Thus, if the controller has been shifted back into first motorway mode 111, it stays in this mode until either the criterion 120 for switching to the second motorway mode 121 is satisfied or the criterion 115 for returning to the base mode 100 is satisfied.

(25) V.sub.4 is selected to be 5 to 20% lower than v.sub.1, in order to avoid constant, irritating switching between the individual control modes with the aid of a hysteresis in the switching procedure. In this example the value for v.sub.4 is 95 kph, t.sub.4 is equal to 10 s, and r.sub.4 may be equal to or smaller than r.sub.2. In this example, r.sub.4=r.sub.1=425 m.

(26) A query procedure 125 is carried out in second motorway mode 121 as well, and in this case a check is made to determine whether criteria for a return to first motorway mode 111 are satisfied. The controller is shifted from second motorway mode 121 to first motorway mode 111 if the current vehicle speed v.sub.F falls below a fifth predefined speed threshold v.sub.5 or the current bend radius r.sub.F falls below a fifth predefined bend radius threshold r.sub.5 for a fifth predefined time period t.sub.5. Thus, if the controller has been shifted back into second motorway mode 121, it stays in this mode until either the criterion 130 for switching to the third motorway mode 131 is satisfied or the criterion 125 for returning to the first motorway mode 111 is satisfied.

(27) V.sub.5 is selected to 5 to 20% lower than v.sub.2, to avoid constant, irritating switching between the individual control modes with the aid of a hysteresis in the switching procedure. In this example the value for v.sub.5 is 95 kph, t.sub.5 is equal to 10 s, and r.sub.5 may be equal to or smaller than r.sub.2. In this example r.sub.5=r.sub.2=425 m.

(28) In the third motorway mode 131, a query 135 is carried out to which whether criteria for a return to the second motorway mode 121 are satisfied. This might be the case for example if the traffic density has increased in the meantime. Accordingly, the controller is then shifted from the third motorway mode 131 back into the second motorway mode 121, if the current vehicle speed v.sub.F falls below a sixth predefined speed threshold v.sub.6 continuously for a predefined sixth time period t.sub.6 or the number of oncoming vehicles does not fall below the predefined number n.sub.max within the third predefined time period t.sub.3. Otherwise, the controller remains in the third motorway mode 131 until the method is ended in an end step 140.

(29) V.sub.6 may be selected to be 5 to 20% lower than v.sub.3, to avoid constant, irritating switching between the individual control modes with the aid of a hysteresis in the switching procedure. In this example, v.sub.6 is equal to 135 kph.

(30) Although the examples shown in FIGS. 1 to 4 illustrate conditions in which driving is on the right, they can equally well be applied to driving on the left with a correspondingly mirrored reversal of positions.

(31) FIG. 5 shows a device for controlling a headlight control system of a motor vehicle according to an embodiment of the present disclosure. Device 50 includes a sensor device 51 with a driving status sensor unit 53 for detecting a driving status of motor vehicle 1 and an environment sensor unit 54 for detecting an environment of the motor vehicle 1. Device 50 also includes a controller 40 and a headlight control unit 45 for controlling a headlight system 52 of motor vehicle 1. Sensor device 51 is designed to capture data from driving status sensor unit 53 and environment sensor unit 54.

(32) In this context, controller 40 has a receiver interface 41 includes a receiver interface for receiving data that represents information about a current driving situation of the vehicle 1. The controller further includes a timer 42 with a current timer status, and an evaluation unit 43 for determining on the basis of the received data and the current timer status whether a current control mode matches a control mode from at least two control modes that is assigned to the detected driving status, wherein each has an associated, predetermined maximum main headlight beam width. Controller 40 further includes an output interface 44 for outputting signals to a headlight control unit 45.

(33) The evaluation unit 43 is designed to command the output interface 44 to send signals to the headlight control unit 45 in order to switching headlight control unit 45 to a control mode 100, 111, 121, 131 with a maximum main beam width b.sub.0, b.sub.1, b.sub.2, adapted to the current driving situation. The receiver interface 41 according to the embodiment shown in FIG. 5 is also designed to receive data that represents information about a current environment of the motor vehicle 1. Evaluation unit 43 is designed to calculate a current traffic density on the basis of this information, determined according to a number of oncoming vehicles 3 within a predefined time period t.sub.3, and to command the output interface 44 to send signals to the headlight control unit 45 for switching the headlight control unit 45 to a control mode 121, 131 with a maximum main beam width b.sub.0, b.sub.2 adapted to the current driving situation and the current traffic density.

(34) While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.