JP2002114089A - Light distribution controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control light distribution in accordance with an actual road shape not only at an entrance of a curve but also after the curve entrance. SOLUTION: When designing a curve shape of a road, it is designed by dividing it into an entrance clothoid section, a constant curvature section, and an exit clothoid section. In this device, an actual shape of a curve is stored as inherent information of a clothoid coefficient, a radius of curvature, or the like. A driver tends to watch a position after passage of a predetermined time Tf seconds regardless of a vehicle speed. So in this device, a headlamp device is controlled by calculating a light distribution angle θ from the inherent information and the vehicle speed v so as to irradiate the position after passage of the predetermined time Tf seconds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light distribution control device, for example, a headlight mounted on a vehicle.
The present invention relates to a light distribution control device that controls an irradiation angle of light.

[0002]

2. Description of the Related Art Conventionally, a road shape ahead of a vehicle position is estimated on the basis of information of an electronic map in a row of dots provided in a navigation device. (Japanese Patent Publication No. 7-71908) has been proposed to control the light distribution angle of a headlamp in accordance with the distance of the headlight to improve visibility on a curve.

[0003]

However, the information of the electronic map in the form of a dot sequence, which is provided in the conventional navigation device, is as follows.
It is created and stored for the main purpose of searching for a route to a destination and displaying an image of a road map. For this reason, the information (including road information) of the electronic map provided in the conventional navigation device is composed of discrete point sequence information, and does not accurately represent the actual road shape. Therefore, since information that does not accurately represent such a road shape is used as basic information when controlling light distribution, it may not be suitable for an actual road, and light distribution control contrary to the driver's intention may be performed. Could be done. Further, in the above-described conventional technology, since the light distribution angle of the headlight (headlamp) is controlled in accordance with the distance from the vehicle position to the entrance of the curve, the light distribution is controlled with respect to the part where the curve starts to bend. However, it is not possible to control the light distribution corresponding to a portion where the curvature is sharp after the entrance of the curve.

Therefore, the present invention has been made to solve the above-mentioned problem, and has as its first object to perform light distribution control suitable for an actual road shape. It is a second object of the present invention to perform light distribution control corresponding to the road shape not only at the entrance of the curve but also after the entrance of the curve.

[0005]

According to the invention described in claim 1, the light distribution for adjusting at least one of the light distribution angle and the irradiation range of the headlight according to the road shape of the traveling road ahead of the own vehicle position. A control device, a current position detecting means for detecting a current position of the vehicle, and a unique information acquiring means for acquiring unique information determined from design conditions of a traveling path ahead of the current position of the vehicle detected by the current position detecting means. The object is achieved by providing a light distribution control device with a light distribution control device that controls at least one of a light distribution angle and an irradiation range of the headlight based on the unique information acquired by the unique information acquisition device. . Claim 2
In the light distribution control device according to claim 1, in the light distribution control device according to claim 1, based on the unique information acquired by the unique information acquisition means, the light distribution control unit performs a A section setting means for setting a section determined by the design conditions of the travel path; and, when the detected vehicle position enters the section set by the section setting means, the headlight of the headlight is set based on the acquired unique information. Light distribution angle calculation means for calculating the light distribution angle; and light distribution angle control means for controlling the light distribution angle of the headlight to be equal to the light distribution angle calculated by the light distribution angle calculation means. It is characterized by. According to a third aspect of the present invention, in the light distribution control device according to the first or second aspect, the light distribution control device further includes a road information storage unit that stores road information indicating a position and a shape of the road. It is stored in road information storage means, and the unique information acquisition means acquires unique information from the road information storage means. According to a fourth aspect of the present invention, in the light distribution control device according to the first, second, or third aspect, the unique information is information based on a clothoid curve. According to the invention described in claim 5, claim 2, claim 3,
Alternatively, in the light distribution control device according to claim 4, the section setting means sets a clothoid entrance section, a constant curvature section, and a clothoid exit section based on the detected unique information.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the light distribution control device of the present invention will be described below in detail with reference to FIGS. (1) Outline of Embodiment When designing a curve shape of a road, it is designed to be divided into an entrance clothoid section, a constant curvature section, and an exit clothoid section. In the present embodiment, the actual shape of the curve is stored as unique information such as a clothoid coefficient and a radius of curvature. on the other hand,
The driver tends to gaze at a position after a lapse of a predetermined time Tf seconds regardless of the vehicle speed. Therefore, in the present embodiment, the specific information and the vehicle speed v are set so that the position is irradiated after a predetermined time Tf has elapsed.
To calculate the light distribution angle θ, and control the headlight device. Specifically, by adding unique information of the road, such as a straight section, a clothoid curve section, and an arc section, to the electronic map information and controlling the light distribution direction based on the unique information, it is suitable for the actual road shape. Perform light distribution control. That is, main roads are constructed in accordance with predetermined design conditions in consideration of ease of vehicle operation and the like. In general, as shown in FIG. 1, the radius of curvature gradually decreases, and thereafter a certain radius of curvature (minimum radius of curvature) continues for a while, and then the radius of curvature gradually increases, so that the vehicle travels straight ahead. It is constructed according to the following design conditions (design criteria). The portion where the radius of curvature gradually decreases and the portion where the radius of curvature gradually increases are designed to approximate, for example, a predetermined curve (clothoid curve). For this reason, in the present embodiment, a portion having a smaller radius of curvature with respect to the traveling direction P of the vehicle is referred to as an “entrance clothoid section”, and a portion having a larger radius of curvature is referred to as an “exit clothoid section”. Further, a section where the curvature radius R is constant is called a “constant curvature section”. The entrance clothoid section and the exit clothoid section can be specified by information (unique information) indicating the degree of curve of the traveling road such as the clothoid coefficient and the section distance as information based on the clothoid curve. The clothoid shape is determined by the clothoid coefficient and the distance. Further, the road shape in the constant curvature section can be specified by information (unique information) indicating the degree of curvature of the traveling path such as a radius of curvature (curvature). This unique information is information expressing the shape of the running curve.
Treated as consisting of two sections. Then, the unique information for each curve is stored. Further, among the node information included in the road information of the navigation device, the node information that coincides with the start point of the entrance clothoid section is associated with the unique information of the curve traveling thereafter.

[0007] Under such a premise, in the vehicle light distribution control device according to the present embodiment, the traveling position (current position) of the own vehicle is detected by the own vehicle position detecting means, and the traveling position of the traveling road ahead of the own vehicle position is detected. An entrance clothoid section, a constant radius of curvature section, and an exit clothoid section are specified from the unique information determined from the design conditions, and the headlight distribution (corresponding to each section) is determined according to which section the vehicle position is located in. The light angle θ is controlled. On the other hand, the light distribution angle θ is calculated by calculating the own vehicle position (position after Tf) after a lapse of a predetermined time Tf from the current position of the vehicle from the unique information such as the clothoid coefficient, and irradiating the calculated position after Tf. Controls the light distribution angle of the illuminator. This is because the driver generally does not depend on the vehicle speed but for a predetermined time (Tf = 1.5 in the present embodiment).
Second) because the user tends to gaze at the position after elapse.
As a result, the light distribution angle θ is, as shown in FIG.
When the vehicle speed v is constant, the light distribution angle θ gradually changes in the entrance clothoid section and the exit clothoid section where the radius of curvature gradually changes according to the clothoid coefficient, and the light distribution angle θ is constant in the constant curvature section. . When the vehicle speed v changes, the light distribution angle θ is increased as the vehicle speed increases, thereby irradiating a point away from the current position of the vehicle (the vehicle position after the lapse of the time Tf), and as the vehicle speed decreases, the light distribution angle θ increases. By reducing the size, a point close to the current position of the vehicle (the position of the vehicle after a lapse of time Tf) is irradiated.

(2) Details of Embodiment FIG. 2 is a block diagram showing a configuration example of a light distribution control device of the present embodiment. As illustrated in FIG. 2, the light distribution control device 1 of the present embodiment includes a navigation device 10, a vehicle speed sensor 31, a light distribution control ECU (Electroni).
c Control Unit) 40 and headlight device 5
0 is provided. The navigation device 10 includes a navigation processing unit 11, a data storage unit 12 as a road information storage unit, a current position detection unit 13, a communication unit 15, an input unit 16, a display unit 17, a voice input unit 18, , An audio output unit 19.

A navigation processing unit 11 performs various arithmetic processing such as navigation processing based on the input information, and outputs a result thereof to a CPU (central control unit) 1.
11 is provided. The ROM 111 and the RAM 113 are connected to the CPU 111 via a bus line such as a data bus. The ROM 112 stores various programs for performing processing such as searching for a planned traveling route to a destination, traveling guidance along the route, light distribution angle control processing, and light distribution angle calculation processing in the present embodiment. Only memory. The RAM 113 is a random access memory as a working memory when the CPU 111 performs various arithmetic processing. In the ROM 112,
An arithmetic expression for calculating the light distribution angle θ used in the light distribution angle calculation processing is stored. This arithmetic expression is stored corresponding to each of the three sections constituting the curve. This arithmetic expression may be defined in a light distribution angle arithmetic processing program. The curve in the present embodiment is a concept composed of one or more continuous corners. A corner is a place where a road is bent at a specific node on the electronic map, and the road including the node and nodes before and after the node is bent.

The data storage unit 12 stores a map data file, a network data file, a unique information file,
The destination data file is stored. The map data file includes terrain data (drawing data), city map data (detailed drawing data), and the like, and the network data includes road data and intersection data as data for map matching and route guidance. I have. The destination data includes name, location, address, photo,
Facility introduction data etc. are included.

The road data stores the following data as information for specifying the road characteristics connecting the intersections. In other words, the road data contains the intersection number, the number of nodes,
The node information, link length, link intersection angle, road width, road name, and the like are stored. Each link stores, as link information, the number of lanes on the road, the presence or absence of a tunnel, and the like. The intersection data includes a road number of a road intersecting the intersection, a guidance target permission flag indicating whether the road is a guidance target, landmark position type data, intersection photograph data, exit rampway guidance data for an expressway, an intersection, and the like. Numbers are stored. The node information is information relating to one point on a road. A connection between nodes is called a link, and a road is represented by connecting each of a plurality of node rows with a link. The road shape can be defined not only by nodes and links but also by altitude. The altitude data is held at each point in a matrix at intervals of 250 m in the left, right, up and down directions. For example, the altitude data is 20 m at the point indicated by 10-10 in the figure.
The altitude point at the point indicated by 0-11 has data such as an altitude of 22m. The radius of curvature of the road at the node (node radius) can be obtained from the crossing angle of the link.

FIG. 3 shows the concept of nodes provided on an actual road and the contents of node information stored in the data storage unit 12 as road data. As illustrated in FIG. 3A, nodes are taken at predetermined intervals to represent a road shape. A road having a straight line has a wider node interval, and a curve has a shorter interval as the radius of curvature is smaller. Each node has a different node number (na-1, na, na + 1,..., Nb-1,
nb, nb + 1,...). Each node is
It is defined by at least coordinates (in the present embodiment, latitude and longitude, which are absolute coordinates). The node information includes
Data for specifying coordinates of each node position, node information such as presence / absence of a railroad crossing, gradient, etc. are stored for each node point.
A node that matches the start point (end point of the curve) of the entrance clothoid section has, as information used in the light distribution angle control processing, a unique information reference number for referring to unique information expressing the shape of the curve, and a progression. The information and the unique information flag are stored as the node information in the road data. In the present embodiment, a node that coincides with the start point of the entrance clothoid section is called a unique information holding node.

As shown in FIG. 3A, the node na
If the section from to the node nb is a curve designed according to the unique information, information such as a unique information reference number for associating the unique information with the nodes na and nb, which are the end points of the curve, is stored. In this case, the node na:
The start point of the entrance clothoid section when the vehicle travels from the node na-1 to the node na corresponds to the node nb
Corresponds to the entrance clothoid section when the vehicle travels from the node nb + 1 to the node nb. And FIG.
As shown in (b), since the road between the nodes na and nb is designed under the same design conditions, the same unique information reference number kx is stored.

A node na, which is an end point of the curve,
nb is the start point of the entrance clothoid section, and at the same time, corresponds to the end point of the exit clothoid section for vehicles traveling in the opposite direction. Therefore, as information for recognizing the entrance clothoid section, a node number existing in the curve is stored as traveling direction information. That is,
By storing the node na + 1 as the progress information of the node na, if the node na + 1 of the traveling direction information exists ahead of the node na in the traveling direction, the vehicle recognizes that the vehicle is traveling toward the curve. , The node na can recognize the start point of the entrance clothoid section. Also, when the node na + 1 of the traveling direction information exists between the current vehicle position and the node na, the vehicle is about to exit the curve and the start point of the entrance clothoid section because the node na is the end point of the exit clothoid section. I do not recognize. Similarly, the node nb-1 is stored as the traveling direction information of the node nb.

As the node number stored in the traveling direction information in this embodiment, the node number next to the node number corresponding to the end point of the curve is stored as a node in the curve. May be stored. Also, the node number outside the curve is stored in the traveling direction information, and if a node of the traveling direction information exists between the current vehicle position and the node corresponding to the curve end point, the node at the curve end point is the starting point of the entrance clothoid section. May be recognized.

The unique information flag stored in association with the curve end point node stores a flag "1" or "0". As the flag, a flag “1” is stored for a right turn curve in which the steering is operated rightward when the vehicle travels the curve, and a flag “0” is stored for a left turn curve operating leftward. You. FIG. 3 (a)
In the unique information for the node na of the road illustrated in the example, since the traveling direction is from the node na to the node na + 1, a flag “1” indicating a right turn curve is stored, and the node nb
Since the traveling direction is from the node nb to the node nb−1, the unique information corresponding to “
0 "is stored.

FIG. 4 conceptually shows the contents of the unique information file stored in the data storage unit 12. As shown in FIG. 4, the unique information file stores a plurality of pieces of unique information corresponding to curves designed in different shapes. Each unique information is assigned a unique information reference number (kx, kx + 1,...). This unique information reference number matches the unique information reference number stored in the node information of the curve entrance node illustrated in FIG. In the unique information file, as the unique information for each curve, the clothoid coefficient A1 and clothoid section distance La1 of the clothoid section 1, the curvature radius R and the circular curve length Lr of the constant curvature section, and the clothoid coefficient A of the clothoid section 2 are included.
2 and clothoid section distance La2. The clothoid section 1 and the clothoid section 2 differ depending on the side on which the vehicle enters the curve, and when the vehicle enters the right curve as shown in FIG. 4B (enters the curve while operating the steering to the right). , The clothoid coefficient Ai of the entrance clothoid section, and the clothoid section distance Lai,
The clothoid coefficient A1 and the clothoid section distance La1 of the clothoid section 1 are used, and the clothoid coefficient A2 and the clothoid section distance La2 of the clothoid section 2 are used as the clothoid coefficient Ao and the clothoid section distance Lao of the exit clothoid section. Conversely, as shown in FIG. 4C, when the vehicle enters a left curve, the clothoid coefficient Ai of the entrance clothoid section and the clothoid section distance L
ai, clothoid coefficient A2 of clothoid section 2;
The clothoid section distance La1 is used, the clothoid coefficient Ao of the exit clothoid section, and the clothoid section distance Lao.
The clothoid coefficient A2 of the clothoid section 2 and the clothoid section distance La2 are used.

Whether to use clothoid section 1 or clothoid section 2 as the data of the entrance clothoid section and the exit clothoid section is determined from the unique information flag of the node information illustrated in FIG. 3B. . The unique information stored in the unique information file is based on a right curve, and data is stored as a clothoid section 1 as an entrance clothoid section and a clothoid section 2 as an exit clothoid section when entering the right curve. Therefore, when the unique information flag is “1” representing the right curve,
Clothoid section 1 is used as the data of the entrance clothoid section, and clothoid section 2 is used as the data of the exit clothoid section. The unique information flag indicates the left curve. "
If it is 0 ", the clothoid section 2 is used as the data of the entrance clothoid section, and the exit clothoid section 1 is used as the data of the exit clothoid section.

The data storage unit 12 includes, in addition to the data files described above, other data files storing information for various areas such as a gas station and sightseeing spot information. In each of these files, while performing a route search, a guide map is displayed along the searched route, characteristic photographs and frame diagrams at the intersection and the route are displayed, the remaining distance to the intersection, the next intersection, The display unit 17 and the audio output unit 19 display the traveling direction of the
Various data to be output from are stored. Of the information stored in these files, intersection data and road data are used for route search in normal navigation. Based on these data, road width, slope, road surface condition, radius of curvature of corner, intersection, T-junction, number of lanes of road, point of decreasing lane, corner entrance, railroad crossing, highway exit rampway, highway Road information indicating a tollgate on the road, a point where the width of the road becomes narrower, a downhill road, an uphill road, a branch road that enters the rampway from an expressway, a branch road such as a Y-shaped road, and the like are configured. .

Each file is, for example, a DVD (Digital)
tal Versatile Disc), MO (Magneto-Optical Disk), CD-ROM (Compact Disc)
cRead Only Memory), optical discs,
Various storage devices such as a magnetic tape, an IC card, and an optical card are used. Although each file has a large storage capacity, for example, it is preferable to use a CD-ROM or a DVD, but individual data such as other data files and data for each area may use an IC card. Also,
The communication unit 15 may be used to acquire data such as traffic congestion information and route information to a destination through communication by an external information providing unit (not shown). Further, similarly, the communication unit 15 may be used to acquire the map data file and the network data file by communication. Alternatively, the network data file can be updated by communication as described above, and the update can be performed by recognizing a new road by comparing the traveling locus of the own vehicle with the corresponding network data. Go to
This is done by creating new road network data.

The current position detector 13 in FIG.
S receiver 131, geomagnetic sensor 132, distance sensor 1
33, steering sensor 134, beacon sensor 13
5, a gyro sensor 136. The GPS receiver 131 is a device that receives a radio wave emitted from an artificial satellite and measures the position of the own vehicle. Geomagnetic sensor 1
Numeral 32 detects terrestrial magnetism to determine the direction in which the vehicle is facing. As the distance sensor 133, for example, a sensor that detects and counts the number of rotations of a wheel, a sensor that detects acceleration and integrates twice, and other measuring devices are used. As the steering sensor 134, for example, an optical rotation sensor or a rotation resistance volume attached to a rotating portion of a steering wheel is used, but an angle sensor attached to a wheel portion may be used. The beacon sensor 135 receives position information from a beacon arranged on the road. The gyro sensor 136 is configured by a gas rate gyro, a vibration gyro, or the like that detects a rotational angular velocity of the vehicle and integrates the angular velocity to obtain the azimuth of the vehicle. Further, the gyro sensor 136 can detect a lateral acceleration (lateral G) applied to the vehicle.

The GPS receiver 13 of the current position detector 13
1 and the beacon sensor 135 can independently measure the position, but in other cases, the distance sensor 133
The combination of the distance detected by the sensor and the azimuth detected by the geomagnetic sensor 132 and the gyro sensor 136, or the combination of the distance detected by the distance sensor 133 and the steering angle detected by the steering sensor 134, The absolute position (current position of the vehicle) is detected. Various types of information detected by the current position detection unit 13 are used to construct precise travel locus data detected for each route based on the present embodiment.

The communication section 15 transmits and receives various data to and from an FM transmitting apparatus, a telephone line, and the like.
For example, various data such as traffic information and traffic accident information transmitted from an information center or the like are received. The input unit 16 corrects the current position at the start of traveling,
It is configured to input a destination. Examples of the configuration of the input unit 16 include a touch panel that is arranged on a screen of a display that configures the display unit 17 and that inputs information by touching keys and menus displayed on the screen, a keyboard, a mouse, and a bar. Code reader,
Examples include a light pen and a remote control device for remote control.

The display unit 17 displays operation guides, operation menus, operation keys, displays a route to a guide point set in response to a user request, and displays various information such as a guide map along a traveling route. Display is performed. As the display unit 17,
A CRT display, a liquid crystal display, a plasma display, a hologram device that projects a hologram on a windshield, or the like can be used. The voice input unit 18 is configured by a microphone or the like, and inputs necessary information by voice. The voice output unit 19 includes a voice synthesizer and a speaker, and outputs guidance information of voice synthesized by the voice synthesizer. Note that, in addition to the voice synthesized by the voice synthesizer, various kinds of guidance information may be recorded in a voice storage device such as a tape and output from a speaker. The sound of the sound storage device may be combined.

The navigation device 10 configured as described above informs the driver of road information around the current location of the vehicle, and guides the traveling route to the destination of the vehicle. That is, when the destination is input from the input unit 16, the navigation processing unit 11 determines the travel route from the road information read from the data storage unit 12 to the destination based on the own vehicle position detected by the current position detection unit 13. The selected route is output to the display unit 17, and the driver is guided to the destination by the traveling route displayed on the display unit 17 and the voice output from the voice output unit 19. When the location mode is selected, the road information around the own vehicle position and the own vehicle position are output to the display unit 17.

The navigation device 1 in the present embodiment
0 is determined based on the current position of the vehicle and the node coordinates as to whether or not the vehicle has entered the curve. If the vehicle has entered, the travel distance and the vehicle speed v from the starting points of the entrance clothoid section, the constant curvature section, and the exit clothoid section are determined. The light distribution angle θ from the unique information according to
Is calculated. As the vehicle speed v, a vehicle speed v detected by a vehicle speed sensor 31 disposed on the vehicle is obtained.
Then, the navigation device 10 calculates the calculated light distribution angle θ.
Is supplied to the light distribution control device 40. Although the navigation device 10 according to the present embodiment has a route guidance function and a location function, in the present invention, the navigation device 10 is configured with each functional portion for controlling light distribution, and may not include other functions. For example, the display unit 17 and the audio output unit 19 for route guidance may not be provided.

The light distribution control device 40 controls the headlight device 50 based on the light distribution angle θ supplied from the navigation device 10.
To control the light distribution angle θ. FIG.
1 illustrates a configuration of a headlight device 50. The headlight device 50 according to the present embodiment is also used as a normal headlight disposed on the left and right sides in front of the vehicle. However, the headlight device may be disposed separately from this. Good. As shown in FIG. 5, the headlight device 50 has a housing for housing the lamp, which includes a lamp body 51 having one open surface, and a front lens 52 disposed on an open surface of the lamp body. ing. A lamp including a light source bulb 53 that emits light by emitting light and a movable reflector 54 that reflects the light emitted from the light source bulb 53 toward the front of the vehicle is disposed in the housing. In addition, a drive mechanism for controlling a light beam emitted from the lamp is provided in the housing. The light distribution control by the driving mechanism is performed by a first mechanism for diffusing and concentrating a light beam emitted from the lamp and a second mechanism for controlling a light distribution angle θ by the light beam.

The first mechanism has a first actuator 55 that supports the light source bulb 53 and moves the light source bulb 53 in the front-rear direction with respect to the movable reflector 54. First
The actuator 55 includes, for example, a rack, a pinion, a drive motor, and the like. The first actuator arranges the light source center 53 a of the light source bulb 53 at the focal point of the movable reflector 54 in a normal state based on a control signal from the light distribution control ECU 40. Then, as shown in FIG. 6A, when diffusing a light beam,
The first actuator 55 moves the light source bulb 53 in a direction away from the movable reflector 54 based on the control from the light distribution control ECU. That is, the first actuator 55 moves the light source center 53a forward of the vehicle (the front lens 52).
Side), and is shifted from the focal point of the movable reflector 54 to diffuse the light beam.

The second mechanism comprises a worm 56, a worm wheel 57, and a second actuator 58. The second actuator 58 is provided with a motor capable of rotating forward and reverse, and a worm 5 is provided at the tip of the rotating shaft of the motor.
6 is attached. The worm wheel 57 that meshes with the worm 56,
It is designed to rotate around the movable shaft 57a. The worm wheel 57 includes a support member 57b extending toward the center of the movable reflector 54.
The movable reflector 54 is fixed to the tip of the support member 57. Therefore, as shown in FIG. 6B, the second mechanism controls the light distribution angle to the left by, for example, driving the second actuator to change the direction of the movable reflector 54 to the left. That is, the second mechanism controls the light distribution angle θ by rotating the second actuator 58 so that the movable reflector 54 rotates left and right about the movable shaft 57a.

The light distribution control ECU 40 controls the navigation device 10 with respect to the headlight device 50 thus configured.
The second actuator 58 of the second drive mechanism is drive-controlled so that the light distribution angle θ supplied from the second drive mechanism is obtained. Light distribution control EC
U has a storage unit for storing the current light distribution angle θ ′ of the movable reflector 54. And the light distribution control ECU 40
The difference distribution light angle Δθ = θ−θ ′ between the current light distribution angle θ ′ stored in the storage unit and the newly supplied light distribution angle θ is calculated. The motor of the second actuator 58 is driven so that the movable reflector 54 moves by an angle corresponding to the difference distribution light angle Δθ, and the value of the light distribution angle θ ′ is updated to the value of the light distribution angle θ.

Next, the operation of the light distribution control device thus configured will be described. FIG. 7 is a flowchart showing the operation of the light distribution control process. The navigation processing unit 11 of the navigation device 10 first searches the database for the road on which the vehicle is traveling (Step 102). That is, the navigation processing unit 11
The current position of the vehicle (own vehicle position) detected by the current position detection unit 13 is acquired, and the road on which the vehicle is currently traveling is specified. Then, the navigation processing unit 11 searches the road data in the data storage unit 12 for a node existing within a predetermined distance Tm ahead of the vehicle current position. In the present embodiment, the predetermined distance Tm is 20 in front of the own vehicle position.
Although 0 m is adopted, the present invention is not limited to this. The predetermined distance Tm may be changed according to the vehicle speed v. For example, the larger the vehicle speed v, the larger the predetermined distance Tm and the lower the vehicle speed. The smaller the predetermined distance Tm, the more the predetermined distance Tm may be set. Further, the distance may be changed as an arbitrary distance.

Next, the navigation processing unit 11 determines whether or not the searched node includes a unique information holding node associated with the unique information of the curve (step 104). As described above, a unique information holding node is a node to which unique information of a curve is associated,
This is a node that matches the start point of the entrance clothoid section (a node that matches the end point of the curve). Therefore, the navigation processing unit 11 checks whether there is a node in which the unique information reference number is stored among the searched nodes,
If it does not exist, it is determined that the unique information holding node does not exist. If there is a node storing the unique information reference number, the traveling direction of the vehicle is determined. That is,
When the traveling direction of the vehicle is from the node in which the unique information reference number is stored to the node direction stored as the traveling direction information of the node, the vehicle passes through the node in which the unique information reference number is stored. Therefore, it can be determined that the vehicle enters the curve, so that the node is determined to be a unique information holding node. If the traveling direction of the vehicle is opposite to the node direction stored as the traveling direction information of the node from the node storing the unique information reference number, the node storing the unique information reference number is Since it can be determined that the vehicle exits the curve by passing through, in this case, it is determined that the node is not a unique information holding node.

When it is determined that the unique information holding node exists within a predetermined distance Tm ahead of the vehicle (step 104;
Y), based on the unique information reference number and the unique information flag (see FIG. 3B), the navigation processing unit 11 acquires the unique information of the curve existing ahead from the unique information file (see FIG. 4) (step). 106). That is, the navigation processing unit 11 determines, as the unique information of the unique information reference number, the clothoid coefficient Ai and the clothoid section distance Lai of the entrance clothoid section, the curvature radius R of the constant curvature section,
The constant curvature section distance Lr, the clothoid coefficient Ao of the exit clothoid section, and the value of the clothoid section distance Lao are acquired. Here, if the unique information flag is “1”, it is determined that the curve existing ahead is a right curve. For example, when the unique information reference number is kx, as shown in FIG. = A1, Lai = La1, R = R, Lr = L
r, Ao = A2, and Lao = La2. On the other hand, if the unique information of the present invention is “0”, it is determined that the curve existing ahead is a left curve. For example, when the unique information reference number is kx, as shown in FIG. = A
2, Lai = La2, R = R, Lr = Lr, Ao = A
1. Acquire Lao = La1.

Next, the navigation processing unit 11 calculates the coordinates of the current position of the vehicle detected by the current position detection unit 13, the coordinates of the starting point of the curve, and the travel distance after passing through the starting point of the curve.
Calculate the position of the vehicle relative to the curve (step 1)
08). In this embodiment, the unique information holding node = curve start point.

The navigation processing unit 11 acquires the current position of the vehicle from the current position detection unit 13 and determines whether or not the vehicle has entered the curve based on whether or not the vehicle has passed through a unique information holding node (= curve start point) ( (Step 109) If the vehicle has not entered the curve (Step 109; N), the process returns to Step 8. On the other hand, if the vehicle has entered the curve (Step 109; Y), the navigation processing unit 11 determines whether or not the vehicle has already passed the curve from the current position of the vehicle (Step 110). ) Does not require light distribution control, so the processing is terminated.

On the other hand, when the vehicle has not passed through the curve (step 110; N), the navigation processing unit 11
Determines whether the vehicle position is an entrance clothoid section, a constant curvature section, or an exit clothoid section, based on the relative position of the vehicle to the curve calculated in step 108.

If the vehicle position is within the entrance clothoid section (step 114), the navigation processing unit 11
The light distribution angle θ is calculated by the light distribution angle calculation processing A (details will be described later) and supplied to the light distribution control ECU 40 (step 11).
6). When the vehicle position is within the fixed curvature section (step 118), the navigation processing unit 11 calculates the light distribution angle θ by the light distribution calculation processing B (details will be described later), and performs the light distribution control E
It is supplied to the CU 40 (step 120). When the vehicle position is within the exit clothoid section (step 122), the navigation processing unit 11 calculates a light distribution angle θ by a light distribution angle calculation process (details will be described later) and supplies the light distribution angle θ to the light distribution control ECU 40 (step 122). 124).

Upon receiving the light distribution angle θ supplied from the navigation processing unit 11, the light distribution control ECU 40 performs light distribution control on the headlight device 50 based on the received light distribution angle θ (step 126). . That is, the light distribution control ECU 4
0 is relative to the second actuator of the headlight device 50.
The angle of the movable reflector 54 is controlled so that the irradiation light emitted from the headlight device 50 has the light distribution angle θ. After performing the above light distribution control, the process returns to step 108 and the calculation of the light distribution angle θ according to the relative position of the vehicle to the curve by the navigation processing unit 11 is repeated. Step 126
Is not the processing of the navigation processing unit 11, but the processing of the light distribution control ECU 40. Therefore, the navigation processing unit 11 may immediately proceed to step 108 after the processing of step 116, step 120, or step 124. .

Next, in the light distribution angle calculation omission A (step 116), the light distribution angle calculation process B (step 120), and the light distribution angle calculation process C (step 124) performed by the navigation processing unit 11, the vehicle speed v Processing for calculating the light distribution angle θ from the unique information will be described. FIG. 8 illustrates a method of calculating the light distribution angle θ (light distribution angle calculation processing A) when the vehicle is traveling in the entrance clothoid section. The navigation processing unit 11 first obtains the vehicle current position from the current position detection unit, and calculates the curvature radius Rc and the tangent angle τc of the vehicle current position, the clothoid coefficient Ai of the entrance clothoid section obtained in step 106, and the entrance clothoid section. Is calculated from the distance traveled from the starting point. here,
The start point of the entrance clothoid section corresponds to the coordinate point of the unique information holding node. In addition, the navigation processing unit 11 calculates the travel distance from the start point of the entrance clothoid section (the distance after passing the start point) based on a signal supplied from the distance sensor 133.

Now, assuming that the traveling distance after passing the starting point of the entrance clothoid section is Lc, the navigation processing unit 1
1 calculates the radius of curvature Rc of the current position of the vehicle from the following equation (1) according to the basic equation of clothoid. Rc = Ai ² / Lc (1)

Using the curvature radius Rc, the navigation processing unit 11 calculates the tangent angle tc of the current position according to the following equation (2). tc = Lc / (2Rc) = Lc ² / (2 × Ai ² ) (2)

Next, the navigation processing unit 11 determines the coordinates (Xc, Y) of the current position of the vehicle in the entrance clothoid coordinate system.
c) is calculated from the following equations (3) and (4) based on the approximate equation of the clothoid curve. Here, as shown in FIG. 8, the entrance clothoid coordinate system defines a coordinate system with the origin of the entrance clothoid section as the origin (0, 0) and the tangent at the start point of the entrance clothoid section as the X axis. Xc = Lc × {1−Lc ² / (40 × Rc ² ) + Lc ⁴ / (3456 × Rc ⁴ )} (3) Yc = {Lc ² / (6 × Rc)} × {1−Lc ² / ( 56 × Rc ² ) + Lc ⁴ / (7040 × Rc ⁴ )｝ (4)

Next, the navigation processing unit 11 calculates the coordinates of the irradiation point in the entrance clothoid coordinate system. That is, when the navigation processing unit 11 irradiates the vehicle current position with a point after the time Tf, the vehicle speed sensor 3
The distance Lct from the current position of the vehicle to the irradiation point is calculated from the following equation (5) based on the current vehicle speed v acquired from Step 1. Lct = v × Tf (5)

The navigation processing unit 11 calculates the radius of curvature Rt at the irradiation point and the coordinates (Xt, Yt) of the irradiation point on the entrance clothoid coordinate system by the following equation (6).
It is calculated from (7) and (8). Rt = Ai ² / (Lc + Lct) (6) Xt = (Lc + Lct) × {1− (Lc + Lct) ² / (40 × Rt ² ) + (Lc + Lct) ⁴ / (3456 × Rt ⁴ )} (7) yt = {(Lc + Lct) 2 / (6 × Rt)} × {1- (Lc + Lct) 2 / (56 × Rt 2) + (Lc + Lct) 4 / (7040 × Rt 4)} ... (8)

Next, the navigation processing section 11 calculates the irradiation direction θ from the following equation (9) from the coordinates of the current position of the vehicle and the coordinates of the irradiation position in the entrance clothoid coordinate system. θct = tan ⁻¹ {(Yt−Yc) / (Xt−Xc)} (9)

Finally, the navigation processing unit 11 calculates the light distribution angle θ from the following equation (10). θ = θct−τc (10)

Next, a method of calculating the light distribution angle θ when the vehicle is traveling in the constant curvature section (light distribution angle calculation processing B) will be described with reference to FIG. First, the navigation processing unit 11 calculates the distance from the current position of the vehicle to the irradiation position. When irradiating the current vehicle position with the position after the time Tf, the current vehicle speed v supplied from the vehicle speed sensor 31 is obtained, and the distance Lct from the following equation (11) to the irradiation position is calculated. Lct = v × Tf (11) Next, the navigation processing unit 11 calculates the light distribution angle θ according to the following equation (12). θ = Lct / (2 × R) (12)

Next, a method of calculating the light distribution angle when the vehicle is traveling in the exit clothoid section (light distribution angle calculation processing C) will be described with reference to FIG. In the present embodiment, for the exit clothoid section, as shown in FIG. 10, the vehicle travels from the end point to the start point at the start point and the end point of the exit clothoid section. From the coordinate point of the unique information holding node (the starting point of the curve), a point (Lai + Lr), which is the sum of the clothoid section distance Lai of the entrance clothoid section and the fixed curvature section distance Lr, is the end point of the exit clothoid section, and this end point. Is a start point (end point of the curve) of the exit clothoid section that has traveled further for a clothoid section distance Lao of the exit clothoid section. As an exit clothoid coordinate system, as shown in FIG. 10, a coordinate system is defined with the origin of the exit clothoid section as the origin (0, 0) and the tangent at the start point of the exit clothoid section as the X axis.

The navigation processing unit 11 first obtains the current position of the vehicle from the current position detection unit, and calculates the radius of curvature Rc and the tangent angle τc of the current position of the vehicle, the clothoid coefficient Ao of the exit clothoid section obtained in step 106, It is calculated from the travel distance from the end point of the exit clothoid section. Now, the travel distance after passing the end point of the exit clothoid section is L
When c is set, the navigation processing unit 11 calculates the curvature radius Rc of the current position of the vehicle from the following equation (13) according to the basic equation of clothoid. ^{Rc = Ao 2 / (Lao-} Lc) ... (13)

Using this radius of curvature Rc, the navigation processing unit 11 calculates the tangent angle tc of the current position by the following equation (1).
Calculate according to 4). tc = (Lao-Lc) / (2Rc) = (Lao-Lc) ² / (2 × Ao ² ) (14)

Next, the navigation processing unit 11 determines the coordinates (Xc, Y) of the current vehicle position in the exit clothoid coordinate system.
c) is calculated by the following equation (1) based on the approximate equation of the clothoid curve.
5) Calculate from (16). Xc = (Lao-Lc) × {1- (Lao-Lc) ² / (40 × Rc ² ) + (Lao-Lc) ⁴ / (3456 × Rc ⁴ )} (15) Yc = {(Lao− Lc) ² / (6 × Rc)｝ × {1- (Lao-Lc) ² / (56 × Rc ² ) + (Lao-Lc) ⁴ / (7040 × Rc ⁴ )} (16)

Next, the navigation processing unit 11 calculates the coordinates of the irradiation point in the exit clothoid coordinate system. That is, when the navigation processing unit 11 irradiates the vehicle current position with a point after the time Tf, the vehicle speed sensor 3
The distance Lct from the current vehicle position to the irradiation point is calculated from the following equation (17) based on the current vehicle speed v acquired from Step 1. Lct = v × Tf (17)

The navigation processing unit 11 calculates the radius of curvature Rt at the irradiation point and the coordinates (Xt, Yt) of the irradiation point on the entrance clothoid coordinate system by the following equation (18).
It is calculated from (19) and (20). Rt = Ao ² / (Lao-Lc-Lct) (18) Xt = (Lao-Lc-Lct) × ｛1- (Lao-Lc-Lct) ² / (40 × Rt ² ) + (Lao-Lc) −Lct) ⁴ / (3456 × Rt ⁴ )｝ (19) Yt = {(Lao−Lc−Lct) ² / (6 × Rt)} × {1− (Lao−Lc−Lct) ² / (56) × Rt ² ) + (Lao−Lc−Lct) ⁴ / (7040 × Rt ⁴ )｝ (20)

Next, the navigation processing unit 11 calculates the irradiation direction θ from the following equation (21) from the vehicle current position coordinates and the irradiation position coordinates in the exit clothoid coordinate system. θct = tan ⁻¹ {(Xt−Xc) / (Yt−Yc)} (21)

Finally, the navigation processing unit 11 calculates the light distribution angle θ from the following equation (22). θ = θct + τc−90 (22)

As described above, according to the light distribution control device of the present embodiment, the light distribution angle of a curve is calculated from road data such as navigation node data which does not always accurately represent the road shape. Instead, a clothoid coefficient, a radius of curvature, and the like, which are unique information used when actually designing a road, are used, so that more accurate light distribution control that matches the actual road shape can be performed.

In the embodiment described above, the unique information is not stored for every curve, but the curves designed with the same unique information are assigned the same unique information reference number and the unique information file is assigned. , The amount of data to be stored can be reduced. In the embodiment described above, both ends of the curve are always nodes, and information such as a unique information reference number is additionally stored for this node information (see FIG. 3B). When data is used, both end points of the curve may be used as end point nodes, and the coordinates (X, Y), traveling direction information, and unique information flag of the end point nodes may be collectively stored in a separate file. In this case, the traveling direction information stores, for example, the coordinates of the end node on the opposite side of the curve that is paired with the end node.

The embodiment of the light distribution control device of the present invention has been described above. However, the present invention is not limited to the described embodiment, and various modifications may be made within the scope described in each claim. Is possible. For example, in the embodiment described above, the case where only the irradiation direction (light distribution angle θ) is controlled based on the unique information of the curve has been described. However, only the irradiation range is controlled, and both the irradiation direction and the irradiation range are controlled. You may make it. In controlling the irradiation range, for example, the irradiation range can be controlled in accordance with the radius of curvature of the irradiation position based on the unique information of the curve. That is, control is performed so that the irradiation range becomes larger as the radius of curvature becomes smaller. When controlling the irradiation range, the navigation processing unit 11 calculates the irradiation range from the radius of curvature of the irradiation position (for example, a point Tf seconds ahead as in the above-described embodiment) and supplies the calculated light irradiation control ECU 40. Light distribution control E
The CU 40 controls the first actuator 55 to control the irradiation range based on the supplied irradiation range. When controlling both the irradiation direction and the irradiation range, the navigation processing unit 11 calculates the light distribution angle θ and the irradiation range at the irradiation point at the light distribution angle θ (for example, using the radius of curvature as described above). Then, the light is supplied to the light distribution control ECU 40.
The light distribution control ECU 40 controls the second actuator 58 according to the light distribution angle θ, and controls the first actuator 58 according to the irradiation range.
The actuator 55 is controlled.

In the above-described embodiment, the case where information based on a clothoid curve such as a clothoid coefficient is stored as unique information as unique information when the curve is designed according to the clothoid curve is described. In the case where the information is designed based on another relaxation curve, information unique to the relaxation curve may be stored in the unique information file as unique information of the curve. In this case, a different relaxation curve is used depending on the curve, and curve information for specifying the type of the relaxation curve is also stored in the unique information file. The navigation processing unit 11 calculates the light distribution angle θ and / or the irradiation range according to a calculation formula corresponding to the curve information.

Further, as the light distribution angle θ, a case has been described in which only the light distribution angle θ in the left-right direction is controlled, but the light distribution angle θ2 in the vertical direction may be controlled, including the above-described modification. In this case, the third driving mechanism is driven in the same manner as the second driving mechanism.
The mechanism is arranged such that the movable reflector 54 is rotatable up and down. Further, in order to calculate the vertical light distribution angle θ2, data representing the height, for example, altitude data is stored in each node. And not as a curve that assumes a plane, but also as a vertical curve (ups and downs),
The unique information reference number and the like are stored in the end nodes of the vertical curve.

[0061]

According to the present invention, it is possible to perform light distribution control suitable for an actual road shape. Further, the light distribution control corresponding to the road shape can be performed not only at the entrance of the curve but also after the entrance of the curve.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for describing an outline of an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a light distribution control device according to the present embodiment.

FIG. 3 is an explanatory diagram showing a concept of a node provided on an actual road and contents of node information stored in a data storage unit 12 as road data.

FIG. 4 is an explanatory diagram conceptually showing the contents of a unique information file stored in a data storage unit.

FIG. 5 is a diagram illustrating a configuration of a headlight device.

FIG. 6 is an explanatory diagram showing an operation state of the headlight device.

FIG. 7 is a flowchart illustrating an operation of a light distribution control process.

FIG. 8 is a diagram illustrating a method of calculating the light distribution angle θ (light distribution angle calculation processing A) when the vehicle is traveling in the entrance clothoid section.

FIG. 9 is a diagram illustrating a method of calculating the light distribution angle θ (light distribution angle calculation processing B) when the vehicle is traveling in a section of constant curvature.

FIG. 10 is an explanatory diagram illustrating a calculation method of a light distribution angle θ (light distribution angle calculation processing C) when a vehicle is traveling in an exit clothoid section.

[Explanation of symbols]

 Reference Signs List 10 navigation device 11 navigation processing unit 12 data storage unit 13 current position detection unit 15 communication unit 16 input unit 17 display unit 18 audio input unit 19 audio output unit 31 vehicle speed sensor 40 light distribution control ECU 50 headlight device 51 lamp body 52 Front lens 53 Light source bulb 54 Movable reflector 55 First actuator 56 Worm 57 Worm wheel 57a Movable shaft 57b Support member 58 Second actuator

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Bunji Ogawa 2-19-12 Sotokanda, Chiyoda-ku, Tokyo F-term in Equos Research Co., Ltd. (Reference) 3K039 AA08 CC01 FD01 FD05 FD12 JA01

Claims (5)

[Claims] 1. A light distribution control device that adjusts at least one of a light distribution angle and an irradiation range of a headlight according to a road shape of a traveling road ahead of a position of a vehicle, and detects a current position of the vehicle. A current position detection unit, a unique information acquisition unit that acquires unique information determined from design conditions of a traveling path ahead of the vehicle current position detected by the current position detection unit, and a unique information acquired by the unique information acquisition unit. A light distribution control device for controlling at least one of a light distribution angle and an irradiation range of the headlight. 2. The light distribution control means sets, based on the unique information acquired by the unique information acquisition means, a section defined by a design condition of the travel path on a travel path ahead of the own vehicle position. Section setting means, when the detected vehicle position enters the section set by the section setting means, a light distribution angle calculation means for calculating a light distribution angle of the headlight based on the acquired unique information, 2. The light distribution control according to claim 1, further comprising: a light distribution angle control unit that controls a light distribution angle of the headlight so as to be equal to the light distribution angle calculated by the light distribution angle calculation unit. apparatus. 3. A road information storage unit which stores road information indicating a position and a shape of a road, wherein the unique information is stored in the road information storage unit, and the unique information acquisition unit is provided from the road information storage unit. 3. The method according to claim 1, wherein unique information is obtained.
3. The light distribution control device according to 1. 4. The light distribution control device according to claim 1, wherein the unique information is information based on a clothoid curve. 5. The section according to claim 2, wherein said section setting means sets a clothoid entrance section, a constant curvature section, and a clothoid exit section based on the detected unique information. The light distribution control device as described in the above.