JP4318301B2 - Vehicle lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a front visibility of a vehicle at the time of running at a changing point of a running road shape such as a curved road or a bent road or at a crossing point. <P>SOLUTION: An illuminating device 1 for a vehicle calculates either a running distance or a running time up to a running road shape changing point or a crossing point estimated to be present in front of a running direction of own vehicle from a present position of the own vehicle and compares it with predetermined reference values REF1, REF2. When either the running distance or the running time is less than REF1, an illuminating control for a front illuminating lamp for a vehicle is carried out while estimating a road shape around the present position of own vehicle through application of the present positional data of vehicle and the road map data. In addition, when either the running distance or the running time is less than REF2 (&lt;REF1), the illuminating control for the front illumination lamp for a vehicle is carried out in response to a result of estimating the road shape around the present position of own vehicle and a detected information of a steering state of own vehicle. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a technique for performing appropriate front lighting in traveling on a curved road, a curved road, an intersection, and the like.

  Regarding the light distribution control of the vehicle headlamp corresponding to the own vehicle traveling path, the following modes are known.

(I) A form in which irradiation control is performed in conjunction with the steering state of the vehicle. (II) A form in which irradiation control is performed based on the prediction result of the runway shape using the navigation system.

  First, in the above-described form (I), for example, there is a system that detects the steering angle using a steering sensor or the like and controls the irradiation direction of the headlamp so as to adapt to the traveling state of the vehicle. Shows good controllability.

  Moreover, in the said form (II), based on road map information and the own vehicle position information on a map, the structure which performs irradiation control, judging the distance to the turning point of the road ahead of the own vehicle and the bending direction is mentioned. For example, see Patent Document 1.) Alternatively, a system is known that performs beam control using a vehicle arrival position after a predetermined time from the current time as a target position (see, for example, Patent Document 2).

JP-A-2-296550

JP 2002-52975 A

  However, the conventional system has the following problems.

  In the above form (I), for example, since the starting point of a curved road or a curved road is not known in advance, when the timing of the irradiation control is delayed, the influence on the driver's front field of view or a sense of incongruity is a problem. The

  Further, in the above form (II), for example, when the road shape database in the navigation system is used to recognize the road shape ahead of the vehicle position as a bent line and the irradiation control is performed according to the runway prediction result, the map matching accuracy And the estimation accuracy of the road shape is a problem. That is, when the map matching accuracy is as low as about 10 m and the estimation accuracy such as the direction of bending of the road based on the data of the map database is low, the light distribution control during the road driving and the slalom driving can be performed with high accuracy. Difficult (Relying on a method that increases the map matching accuracy and positioning accuracy more than the current situation will have a significant hindrance to practical use.)

  Therefore, when the vehicle approaches a curved road, a curved road, an intersection, etc., is it possible to predict the change point of the running road shape in advance and perform appropriate irradiation control according to the course change of the vehicle? Or, it is difficult to realize unless high control accuracy is guaranteed.

  Therefore, an object of the present invention is to improve visibility in front of a vehicle when the vehicle travels at a change point or intersection of a road shape such as a curved road or a curved road in a vehicle lighting device.

  In order to solve the above-described problems, the present invention includes the following two control modes.

・ First control mode = Control mode that obtains the current position data of the vehicle and controls the irradiation of the vehicle headlamp while estimating the road shape around the current position of the vehicle using the road map data. Control mode = current position data of the vehicle is acquired, road shape data is used to estimate the shape of the road around the current position of the vehicle, and the vehicle headlight is detected based on the detection information of the steering state of the vehicle. Control mode for performing irradiation control.

  Then, the travel distance or travel time from the current position of the vehicle to the shape change point or intersection of the track that is predicted to be present in the forward direction of the host vehicle is calculated, and the first and second criteria determined in advance are calculated. Compare with the value. The first control mode is selected when the travel distance or travel time is less than or equal to the first reference value, and the travel distance or travel time is less than or equal to the second reference value smaller than the first reference value. If so, the second control mode is selected.

  Therefore, in the present invention, before entering the runway shape change point or intersection, the vehicle headlamp is controlled in accordance with the first control mode, and the vehicle approaches the runway shape change point or intersection. In this case, it is possible to perform the irradiation direction control in consideration of the steering state of the vehicle according to the second control mode.

  According to the present invention, it is difficult to solve by only one of the above forms (I) and (II) by changing the irradiation control content according to the approach position of the host vehicle to a curved road, a curved road, an intersection, or the like. It is possible to overcome the problem and improve the forward visibility when traveling on a curved road or the like to increase the driving safety.

  In the first control mode, the distance and direction from the current position of the vehicle to the shape change point or intersection are calculated, and the irradiation direction or irradiation range of the vehicle headlamp is changed according to the distance and direction. By doing so, it is possible to control so as not to cause a timing delay in the irradiation direction or the like before entering a curved path, a curved path or the like.

  Further, in the second control mode, the first control amount for the irradiation direction or the irradiation range of the vehicle headlamp determined based on the detection information of the steering state of the host vehicle, and the travel path in the traveling direction of the host vehicle Compared to the second control amount for the irradiation direction or irradiation range of the vehicle headlamp determined based on the shape estimation result, the larger one of the first and second control amounts is selected and selected Irradiation control is performed according to a later control amount. That is, the irradiation direction or irradiation range of the vehicle headlamp calculated based on the steering state of the host vehicle, and the irradiation direction of the vehicle headlamp calculated based on the estimation result of the runway shape in the traveling direction of the host vehicle Alternatively, if the larger one of the irradiation ranges is selected, the control can be prioritized when greater control is required for changing the irradiation direction or irradiation range. For example, when information on the steering state of the host vehicle is reflected in the irradiation control, priority can be given to the steering angle or the like, thereby making it possible to perform irradiation control in accordance with the driving situation and the actual condition of the road.

  FIG. 1 shows an example of the basic configuration of the present invention.

  The vehicle lighting device 1 includes the following components in order to realize irradiation control according to the above-described control mode (the numbers in parentheses indicate symbols).

・ Vehicle current position detection means (2)
・ Road information provision means (3)
・ Road shape estimation means (4)
.Vehicle steering state detection means (5)
.Vehicle running state detection means (6)
・ Irradiation control means (7)
.Drive means (8)
-Vehicle headlamps (9).

  The own vehicle current position detecting means 2 is provided for obtaining current position information of the own vehicle. For example, a navigation device using GPS (Global Positioning System) by satellite communication or road-to-vehicle communication (a road map database provided from a recording medium such as CD-ROM or DVD-ROM, satellite communication or road The current vehicle position on the road can be detected using position data obtained by using inter-vehicle communication, direction data of the own vehicle, and vehicle speed data. The current position information of the own vehicle is sent to the road shape estimation means 4 and the irradiation control means 7.

  The road information providing means 3 provides, for example, road map database data necessary for map matching, route guidance, and the like, and the output data is sent to the road shape estimating means 4 and used for running path prediction.

  The road shape estimation means 4 estimates the road alignment and predicts the presence of a curved road, a curved road, an intersection, etc. in front of the host vehicle, and sends the estimation result to the irradiation control means 7. In other words, the travel map information is obtained using the road map data, and a plurality of nodes (road notation points) located before and after the current position of the own vehicle using the current position data of the vehicle from the current position detection means 2 of the own vehicle. ), And the road shape modeled by connecting multiple nodes related to the vehicle's travel path by interpolation processing (three-point circular interpolation method, bisection circle method, Newton four-point forward interpolation method, etc.) (Linear) data can be generated.

  The vehicle steering state detection means 5 detects the steering state or the traveling direction (direction) of the host vehicle. For example, the steering state of the vehicle including the turning direction of the vehicle is detected using a steering sensor, an angular velocity sensor, etc., and the detection information is sent to the irradiation control means 7. Alternatively, an azimuth change amount detected using an azimuth sensor such as a gyro sensor is sent to the irradiation control means 7.

  The vehicle running state detection unit 6 detects the vehicle speed, acceleration, and the like of the host vehicle, and sends the detection result to the irradiation control unit 7. For example, to calculate the travel time required to reach the shape change point when the host vehicle enters a road change point such as a curved or curved road or an intersection, the current vehicle speed Data is needed.

  The irradiation control means 7 processes the information from the current position detection means 2, the road shape estimation means 4, the vehicle steering state detection means 5, and the vehicle traveling state detection means 6 to drive the irradiation control output corresponding to the traveling situation. It sends out to the means 8 and performs irradiation control of the vehicle headlamp 9.

  For example, when the travel distance or travel time to the intersection where the shape of the track is predicted to exist ahead of the vehicle traveling direction with respect to the current vehicle position as a reference is indicated as “X”, the irradiation control means 7 “X” is calculated based on the current position information, road shape estimation results, vehicle speed data, travel distance data, and the like. Then, it is compared with a predetermined first reference value (hereinafter referred to as “REF1”) and a second reference value (hereinafter referred to as “REF2”). As for the value of REF1, for example, as a travel distance within a predetermined time at the current vehicle speed of the vehicle, a travel distance of about 1.5 seconds to 3.5 seconds (this distance corresponds to the point of gaze position). preferable. Further, the value of REF2 is smaller than the value of REF1, and is defined according to the map matching accuracy (the higher the map matching accuracy, the smaller the REF2 value can be made).

  In X determination using REF1 and REF2, the first control mode is selected when “X ≦ REF1”, and the second control mode is selected when “X ≦ REF2”. The That is, different control modes are switched depending on the approaching situation such as a curved road and a curved road.

  In the first control mode, it is predicted that there are curved roads, curved roads, and intersections within a predetermined range in the traveling direction of the vehicle, and irradiation of the vehicle headlamp is performed while estimating the road shape around the current position of the vehicle. Control is performed. For example, the travel distance and direction from the current position of the vehicle to the shape change point or intersection are calculated, and the irradiation direction of the vehicle headlamp is changed according to the distance and direction, or the irradiation range is changed. Yes (range expansion etc.).

  When the irradiation angle (or the amount of expansion of the irradiation range) of the vehicle headlamp based on the traveling direction of the host vehicle is denoted as “θ”, when the vehicle enters a curved road, the value of the θ is For example, there is a mode in which control is performed by setting “θ = arctan (0.5 · (W / D))”. Here, “arctan ()” represents an arc tangent function. Further, “W” indicates the own lane width, and “D” is a predetermined time (for example, 1.5 km) with respect to the current vehicle speed of the own vehicle (for example, 40 km / hr or more) or the legal vehicle speed of the traveling road. The traveling distance within about 3.5 seconds).

  When the presence of an intersection is predicted on the course of the vehicle, when the distance or traveling time to the intersection is REF1 or less and the direction indicator is operated by the driver, a predetermined amount of irradiation is performed in the direction according to the instruction. It is preferable to perform irradiation control with an angle or expand the irradiation range with a predetermined amount so that the direction is included. Alternatively, when the route of the vehicle is set in advance in the route guidance, the headlamp illumination control is performed with a predetermined amount of irradiation angle in the direction according to the setting instruction, or a predetermined amount so that the direction is included. It is preferable to expand the irradiation range.

  Further, in the second control mode, considering that the traveling direction and the steering state of the vehicle are changed according to the driving operation, not only the estimation result of the road shape around the current position of the own vehicle but also the steering state of the own vehicle. Based on the detected information, irradiation control of the vehicle headlamp is performed.

  For example, the following processing is performed.

(1) Obtaining the control amount (first control amount) related to the irradiation direction or irradiation range of the vehicle headlamp based on the detection information of the steering state of the own vehicle (2) The shape of the track in the traveling direction of the own vehicle A control amount (second control amount) related to the irradiation direction or irradiation range of the vehicle headlamp is obtained based on the estimation result. (3) The first control amount is compared with the second control amount. 4) The larger one of the first and second control amounts is selected, and irradiation control is performed according to the control amount after selection.

  Note that the order of (1) and (2) above may be reversed.

  In the second control mode, the process (4) is employed in order to avoid adverse effects caused by control accuracy and the like. In other words, it is difficult to perform irradiation control while driving on a curved road or slalom while trusting only the road linear prediction of the road, for example, when the second control amount corresponding to the curved road shape is insufficient. The irradiation direction can be defined by employing the first control amount calculated based on the steering information (in this case, “first control amount> second control amount”).

  The driving means 8 includes all of a driving mechanism, an actuator, a control circuit, etc. for changing the posture and position of optical elements such as a reflecting mirror and a lens, a light shielding member and a light source constituting the vehicle headlamp 9. It is. The vehicle headlamp 9 may be a headlamp, a fog lamp, or the like, but may be a configuration using a lamp capable of controlling light distribution alone or a configuration combining a plurality of lamps.

  In the application of the present invention, for example, a configuration form in which an ECU (electronic control unit) is connected by an in-vehicle LAN (Local Area Network) as described below is adopted.

-The current vehicle position information and road information are sent to the navigation ECU and road shape estimation processing is performed in the ECU, and vehicle steering state detection information and vehicle running state detection information are sent to the irradiation control ECU. A configuration in which the irradiation control ECU that receives the processing result of the navigation ECU via the LAN performs the irradiation control of the headlamps. The navigation ECU performs one of the processes by the irradiation control ECU. (Emission control ECU is not required, or the irradiation control ECU performs minimum processing necessary for irradiation control.)
The navigation ECU simply outputs map data, current position data, and the like, and the irradiation control ECU performs all processing including road shape estimation.

  As for the mechanism required for headlamp irradiation control, for example, in the case of a configuration in which a desired irradiation direction of a part of a beam is changed, a part of optical components such as a reflector and a lens is an actuator. And the like (for example, a configuration in which a movable reflecting mirror driven by a motor is attached to a fixed reflecting mirror). In the configuration in which the irradiation direction of the entire irradiation beam is changed to a desired direction, a driving mechanism for moving the entire lamp optical system is provided, and the lens or the reflecting mirror constituting the optical system is moved in its entirety. (A specific configuration of the lamp is described in detail because various modes capable of controlling the light distribution are known and the configuration is not limited as far as the present invention is concerned. (Omitted).

  Next, the definition of the nodes and links necessary for grasping the road alignment relating to the own vehicle traveling path will be described with reference to FIG.

  In the figure, “Ni” (i = 0, 1-6) represents the i-th node, and “Li” (i = 0, 1-5) represents the i-th link. In this example, a link formed by connecting two adjacent nodes Ni and Ni + 1 with a line segment is defined as Li (the length of Li, that is, the link length is not necessarily constant). ).

  The home base symbol shown in the figure represents the current position of the vehicle (the direction of the sharp point indicates the vehicle traveling direction), and the node N1 existing behind it is defined as the “current node” and in front of it. The located node N2 is defined as “front node”. As for the link, the link where the vehicle exists, that is, the link L1 connecting the nodes N1 and N2 is defined as the “current position link”, and the link L2 ahead is defined as the “forward link”.

  The data related to the road alignment of the road is composed of point data (nodes) and line data (links), and based on a plurality of node information located before and after the current position of the vehicle, the road shape ahead of the vehicle For example, the lamp irradiation position can be determined in a timely manner by predicting the vehicle arrival position after a predetermined time has elapsed.

  In a road map database used for a navigation device or the like, for example, the following characteristic properties are recognized between the node dot characteristics and the road linear characteristics (see Table 1 below).

-The node hitting interval is rough on straight roads (and therefore the link length is large), and the node hitting point interval is dense on curved roads.-The road class is low for the node hitting interval in the curved section (design vehicle speed value). The smaller the road, the shorter the road.

  When section determination is performed according to road design speed and class, it is possible to identify straight roads, curved roads, or intermediate roads (curvature sections, curved roads, etc.) using node intervals. is there.

  Examples of the section discrimination include the following methods, which can be used independently or in combination.

(I) Configuration form in which section length is determined by comparing the link length with a reference distance determined from the legal travel speed of the travel route (II) Configuration form in which link section characteristics are determined using the outer product of link length and link vector (III) A configuration in which link section characteristics are determined based on a sign change of radius R calculated by circular interpolation and an R value (absolute value) using three adjacent nodes.

  First, in (I), for example, the link length between adjacent nodes is compared with a reference distance value determined in advance based on the second speed related to the legal travel speed. The reference distance value can be defined as a constant multiple of the second speed converted value, taking Table 1 as an example. For example, in the case of the target road C (80 km / hr), if a reference distance value corresponding to 10 times the second speed value is defined and the link length is equal to or greater than the reference distance value, the runway section related to the link Is determined to be a straight section. Further, when the link length is less than 10 times the second speed value, the runway section for the link to be determined is an inflection section (5 to 10 times) or a curved section (5 times or less). Is determined. In this configuration, since it is only necessary to compare the link length with the reference distance, it is preferable to combine with (II) and (III) in terms of accuracy.

  In the above (II), by determining the sign change of the outer product of the link vectors obtained as the difference between the link length between adjacent nodes and the position vector of the nodes, the type of the runway section related to the target link can be determined. . That is, the outer product of the link vector corresponding to the link “Li-1” and the link vector corresponding to the link “Li” is denoted as “Li-1 × Li”, the link vector corresponding to the link “Li”, and the link When an outer product with a link vector corresponding to “Li + 1” is written as “Li × Li + 1”, a section over three links (4 nodes) by grasping how the codes change. Judgment is possible. For example, each cross product value is zero in the straight section, and the sign of the cross product changes from positive to negative (or from negative to positive) in the inflection section.

  In (III) above, it is possible to know the curvature radii Ri-1, Ri, Ri + 1,... By performing circular interpolation on the three nodes constituting the two adjacent links. By obtaining the absolute value, the type of the runway section related to the target link can be determined. For example, when the radius of curvature is greater than or equal to a predetermined reference value (such as 1000 m), the straight section is determined, and the curvature radius is less than the predetermined reference value, and the sign of the curvature radius is positive to negative. When changing to (or from negative to positive), an inflection section or the like is determined.

  In (II) and (III), it is possible to accurately determine the type of the track section using the vector product and the radius of curvature.

  FIG. 3 shows a traveling example of an S-shaped curve, and shows nodes N0, N1-N4 and links L0, L1-L3.

  In the embodiment in which the above (III) is adopted for the determination of the curve section, in this example, L1 is the current position link, and the front two nodes N2, N3 and the rear are based on the vehicle current position indicated by the home base symbol. The radius of curvature (or turning radius) “R1” is obtained by applying three-point circular interpolation to one node N1. Then, the radius of curvature “R2” is obtained by applying the three-point circular interpolation to the nodes N3, N4 and the node N2 with the next L2 as a reference.

  The sign of the radius value (R1 or R2) is defined so as to be opposite in accordance with the curve turning direction. For example, the radius value is positive in the case of the right curve, and the radius value is negative in the case of the left curve. Value (or vice versa).

  When curved sections continue like a S curve, the sign of the radius value changes when the vehicle passes a certain point (node N2 in this example). For example, according to the above definition, when R1 is a positive value, R2 is a negative value, and the current position link is L2, the sign of the radius value changes.

  That is, with respect to a plurality of nodes within a predetermined range including the current position of the vehicle, specifically, for three nodes constituting two adjacent links among links formed by connecting adjacent nodes. If circular interpolation is applied, the radius of curvature of the road section that the vehicle is about to pass through can be obtained.

  Examples of the interpolation method used in the road shape estimation means 4 include a bisection circle method and Newton's four-point forward interpolation method in addition to the three-point circular interpolation method, and the use of these methods is not appropriate. In the section, smoothing processing described later is used.

  In the three-point circular interpolation method, vertical bisectors are drawn for adjacent links, and the intersection of the two is used as the center of the arc (curvature center).

  When three-point interpolation is used continuously, for example, an arc having a radius Ri-1 is obtained from the adjacent link pair "Li-1, Li", and the next link pair "Li, Li + 1" is obtained. When an arc having a radius Ri is obtained, there is a problem that both arcs are duplicated on the nodes Ni to Ni + 1. That is, in the inflection section where the sign of the radius changes, the discontinuous circle method is used when the discontinuity of the runway shape becomes significant. That is, circular interpolation is performed for the first three points, and the tangent circle on the extension line of the bisector is used from the next node.

  Further, when Newton's four-point forward interpolation method is used, each position coordinate of the four-point node is expressed as “(xi, yi)” (i = 0, 1, 2, 3). The following equation “y (x)” is obtained.

Incidentally, "Δy0" is first-order difference, "delta ² y0" the second floor difference "delta ³ y0" is a third-order difference, is defined by the following equation.

  FIG. 4 is an explanatory diagram of the smoothing process.

  In a section (bending section) in which sections having a long link length are connected in a polygonal line as shown by L1 and L2, a process of smoothly connecting links with an arc having a predetermined radius R in the vicinity of the bending point shown by the node N2 is performed. preferable.

  “Α” in the figure indicates an angle formed between the links L1 and L2. When the angle of the bending section is expressed using α, the radius R value depends on the α value, but is preferably set to a value slightly larger than the design radius of the road alignment (linear radius) ( For example, in the case of a road at a speed of 40 km / hr, R is set to about 30 m, and the gap distance between the bending point and the arc (R) is set so as not to exceed one lane width.

  It is preferable that a new node is generated in the section subjected to the smoothing process, as shown by points Na and Nb, and the runway shape is redefined in detail.

  Regarding the relationship between the definition of the runway shape and the interpolation method, the current position link L1 and the forward link L2 are exemplified by a combination of a curved section, an inflection section, and a straight section as shown in the following table.

  When both L1 and L2 are curved sections, a three-point circular interpolation method and a bisectoral circle method are preferable. When L1 is an inflection section and L2 is a curved section, for example, L0, Four-point forward interpolation is preferable in L1 and L2, but it is also possible to define L1 as a straight section in a section other than L1 and perform three-point circular interpolation in other sections.

  When L1 is a straight section and L2 is a curved section, for example, L0 and L1 are straight sections (thus primary linear interpolation), and N2 can be defined as a curved starting point.

  In the case where L1 is a curve section and L2 is an inflection section, for example, 4-point forward interpolation centering on the current position link is preferable. If both L1 and L2 are inflection sections, for example, it is preferable to apply a four-point forward interpolation method centered on the current position link, but smoothing is defined by defining a bending path with N2 as the bending point. Processing may be performed.

  When L1 is a straight section and L2 is an inflection section, for example, in a bending section including L1 and L2, N2 may be defined as a curve start point and L2 and L3 may be defined as a curve section.

  When L1 is a curved section and L2 is a straight section (when the link length is long), it is desirable to apply 3-point circular interpolation or 4-point forward interpolation in sections other than L2. Alternatively, the runway may be defined with N2 as the track end point and N3 as the track start point.

  When L1 is an inflection section and L2 is a straight section (when the link length is long), 3-point circular interpolation or 4-point forward interpolation is desirable in sections other than L2. Further, L1 and L2 may be defined as bent sections centered on N2.

  When L1 is a straight section and L2 is a straight section (when the link length is long), for example, smoothing processing can be performed with a linear radius in road design in a bending section with N2 as a bending point.

  In the above example, 3 × 3 = 9 types of road linear shape definitions are possible, and an appropriate interpolation method can be used according to the determination result of the link characteristics and the travel section. Since it is difficult to deal with all road shapes as a real problem, it is preferable to appropriately use the smoothing process using the curvature radii in the design of road alignment as described above.

  Moreover, it is preferable that the road shape estimation means 4 is configured so that, for example, the following information can be calculated based on the result of data generation relating to the road shape.

-Curvature radius of curvature (turning radius) predicted at the front of the host vehicle and the start and end points of the track-Bending point direction angle (clipping point angle, as seen from the driver's seat) on the predicted track ahead of the host vehicle In other words, with respect to the axis extending in the traveling direction of the vehicle, the angle formed between the line of sight, the contact point on the road alignment and the line connecting the vehicle)
-Bending angle in a bending path (see “α” in FIG. 4), etc.

  In the shape estimation process related to road alignment, the accuracy of the current vehicle position is important. For example, the current vehicle position correction process is performed according to the following procedure.

(1) Calculate the predicted range of azimuth change in the target link (link assumed to be the current position link) based on the road linear shape equation estimated from the road shape data generated by the section discrimination and interpolation processing described above (2) If the direction detection data related to the host vehicle is out of the predicted range of (1), it is determined that the current position of the host vehicle does not exist on the link of (1), and the vehicle is positioned around the link. The target is changed to the link before and after the vehicle, and the correction process of the current position of the vehicle is continued. (3) When the direction detection data related to the vehicle is included in the prediction range of (1), the link of (1) The position that is the same as the direction detection data or the closest direction to the data is estimated as the current position of the host vehicle, and the position is corrected. (4) Return to (1) and repeat the process.

  FIG. 5 is a flowchart showing an example of irradiation control processing according to the present invention.

  First, in step S1, necessary information shown below is read into the apparatus.

・ Road map data used for navigation systems ・ GPS data ・ Vehicle speed data ・ Direction data (rate gyro detection information, etc.)
・ Detection data such as steering angle and driving operation data.

  In addition, although road map data etc. are acquired as needed, other data are acquired with a predetermined sampling period.

  In the next step S2, map matching is performed according to a predetermined procedure to determine the road on which the host vehicle is currently traveling, and the current position of the host vehicle on the traveling path is calculated. In the case of a single road, two adjacent nodes are obtained based on the GPS coordinates, and the location that is the shortest point on the link between the two nodes from the GPS coordinates is set as the current vehicle position after matching. In addition, when the road is not a single road (for example, when there are a plurality of roads in the vicinity of the vehicle such as a hairpin curve or an urban area), the current vehicle position is temporarily estimated on the link with the highest reliability based on the GPS coordinates and the direction data. decide. It should be noted that the current position estimation accuracy can be further improved by using a method of constantly or periodically comparing the travel locus obtained from GPS data, vehicle speed, and direction data with the road shape on the road map.

  In step S3, it is determined whether or not the presence of a curved road, a curved road, an intersection, or the like is predicted within a predetermined distance or a predetermined traveling time from the current position of the vehicle. And when it is estimated that a curved road, a curved road, an intersection, etc. exist ahead of the own vehicle, it progresses to the following step S4, but when it is estimated that they do not exist, it progresses to step S8.

  In step S4, the distance and direction to a shape change point (including a bending point) such as a curved road, a curved road, and an intersection are calculated based on the current vehicle position, and the process proceeds to next step S5.

  In step S5, the “X” (distance to the road shape change point or intersection) is compared with the REF1 and REF2. If “REF2 <X ≦ REF1”, the process proceeds to step S6. If “X ≦ REF2”, the process proceeds to step S7.

  In step S6, irradiation control is performed according to the first control mode (for example, the irradiation direction is changed by a control amount corresponding to the θ).

  In step S7, irradiation control is performed according to the second control mode.

  In the case of “X> REF1,” the traveling distance to the shape change point or intersection of the traveling road in front of the vehicle is long, and various irradiation control methods can be applied. For example, the vehicle position (vehicle arrival position) after a predetermined time of the host vehicle is predicted, and the direction of the irradiation beam is controlled using the position as the gazing point, or the irradiation beam using the clipping point of the single curve The form etc. which control the direction of are mentioned. The clipping point is a contact point when a shoulder line or a center line is obtained from the shape line of the running road and a tangent is drawn from the vehicle position with respect to the shoulder line or the center line (the shoulder line or the center line and the tangent line). In addition, the angle of the clipping point means an angle formed between an axis extending in the traveling direction of the vehicle and a tangent drawn from the vehicle position to the shoulder line or the center line, It can be obtained by a known method (tangent circle method) using road shape data (linear data). Further, in the case of a straight road, a method that does not perform any other irradiation control (such as setting the irradiation direction and the irradiation range to a predetermined reference state) can be employed.

  In step S8 following step S6 or S7, it is determined whether or not the elapsed time up to the present time is outside the map matching period (that is, the map matching process is performed at a constant period). If it is within the map matching period, the process returns to step S3. If it is outside the map matching period, the process proceeds to the next step S9, where driving operation data including the steering angle is read, and if necessary, GPS data, vehicle speed After reading data, direction data, etc., the process returns to step S2.

  For the processing described above, for example, CPU (central processing unit), memory, hardware such as input / output ports, and programs executed by the CPU are used as internal processing of an ECU (electronic control unit) incorporating a computer. Realized.

  Thus, according to the above-described configuration, a shape change point including an inflection point of a runway, an intersection, and the like are predicted from the current position of the vehicle and the road shape by the navigation device or the like, and the irradiation control considering the actual steering state is bent. It can be performed on a road section such as a road or a curved road. As a result, even if the map matching accuracy and the like are not sufficient, it is possible to realize irradiation control that does not cause discomfort or discomfort for the driver.

It is a figure which shows the basic structural example of this invention. It is explanatory drawing about the definition of a node and a link. It is explanatory drawing which showed the example of driving | running | working of a curved road. It is explanatory drawing of a smoothing process. It is a flowchart figure which shows an example of irradiation control.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle lighting device, 2 ... Own vehicle present position detection means, 4 ... Road shape estimation means, 5 ... Vehicle steering state detection means, 7 ... Irradiation control means, 9 ... Vehicle headlamp

Claims (3)

The first control mode that controls the irradiation of the vehicle headlamp while acquiring the current position data of the vehicle and estimating the road shape around the current position of the vehicle using the road map data, and the vicinity of the current position of the vehicle In the vehicle lighting device having the second control mode for performing the irradiation control of the vehicle headlamp based on the estimation result of the road shape and the detection information of the steering state of the host vehicle,
Calculate the travel distance or travel time from the current position of the vehicle to the shape change point or intersection of the travel path predicted to exist ahead of the travel direction of the host vehicle, and the travel distance or travel time is determined in advance Compared to the second reference value,
The first control mode is selected when the travel distance or travel time is less than or equal to the first reference value, and the second travel distance or travel time is smaller than the first reference value. The vehicle lighting device, wherein the second control mode is selected when the value is equal to or less than a reference value. The vehicle lighting device according to claim 1,
In the first control mode, the distance and direction from the current position of the vehicle to the shape change point or intersection are calculated, and the irradiation direction or irradiation range of the vehicle headlamp is changed according to the distance and direction. An illumination device for a vehicle. The vehicle lighting device according to claim 1,
In the second control mode, the first control amount for the irradiation direction or irradiation range of the vehicle headlamp calculated based on the detection information of the steering state of the host vehicle, and the road in the traveling direction of the host vehicle Compared with the second control amount for the irradiation direction or irradiation range of the vehicle headlamp calculated based on the shape estimation result, the larger one of the first and second control amounts is selected. Irradiation control is performed according to the control amount after selection.

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