JP2009110394A - Road sign display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To notify a driver of a content of a road sign in a state that it is easily recognized. <P>SOLUTION: The road sign display device has a road sign display priority database 103c for storing a data table for setting order of priority to be displayed in a picture to every road sign. A road sign extracted from a camera 113 image or extracted from a map database 102 by a route guide processing part 101 is collated by the data table, a guidance order of priority determination part 103 sorts road signs to be displayed to a display device 114 and preferentially displays the road sign on the basis of the order of priority granted to the road sign. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a road sign display device that acquires a road sign in advance and displays it to a driver, and more particularly, to a road sign display device that selects a road sign to be displayed based on a predetermined priority.

2. Description of the Related Art Conventionally, when a vehicle is traveling, there are many matters that must be concentrated on the driver, such as confirming safety in the direction of travel, confirming pedestrians, and confirming signals in addition to driving operations. Further, when fatigue is accumulated in the driver due to long-time driving or the like, it may be difficult to maintain concentration. Furthermore, in the case of a driver who has little driving experience, the driver is often not used to concentrating on the confirmation items other than the driving operation as described above.
In such a case, the road sign may be overlooked while traveling, and if the sign is a regulatory sign, troubles such as violation of laws and regulations may occur due to oversight.

For this reason, conventionally, devices described in Patent Document 1 and Patent Document 2 have been proposed. In Patent Document 1, a road sign is recognized, and the contents are displayed on a screen by a document or notified by voice. Further, the apparatus described in Patent Document 2 records a video image and, when a sign is recognized, reproduces video for a certain period of time before and after the sign is shown.
JP-A-5-174294 JP-A-6-036183

  In the device described in Patent Document 1, since the contents of the sign are displayed to the driver using the road sign information as character information, the driver who is driving needs to read the character information displayed on the screen. There is a possibility of carelessness with the movement, and there is a safety problem. In addition, when notifying the road sign information by voice, the driver needs to listen to the output voice to the end, so it takes time to understand the notification contents, and the sign must be There is a problem of passing.

  Moreover, in the apparatus described in Patent Document 2, when a large number of road signs are recognized, a large number of road signs are simultaneously displayed to the driver. There is also a risk that a completely unnecessary road sign will be displayed. For example, when a “pause” sign 10 meters ahead is guided while traveling at 40 km / h, it is difficult to stop at the sign position. In addition, if the user turns right or left immediately after acquiring the image information, the acquired image information does not make sense.

As described above, the device described in Patent Document 2 includes not only the most important or more necessary road signs but also the necessity level when the road signs are obtained as road signs displayed to the driver. Low road signs and road signs that are completely unnecessary. This is rather confusing to the driver.
An object of the present invention is made in view of the above-described facts, and it is an object of the present invention to provide an apparatus capable of notifying a driver of the contents of a road sign in a state in which recognition is easy.

The present invention for solving the above problems has the following configuration.
(1) Sign information acquisition means for acquiring visual information of a road sign located in the traveling direction of the vehicle,
When there are a plurality of pieces of sign information acquired by the sign information acquisition means, display rank determination means for determining the display rank according to a predetermined rank;
A road sign display device comprising: display means for displaying visual information of road signs in accordance with the order determined by the display order determining means.

(2) The sign information acquisition means includes:
Current position acquisition means for acquiring the current position of the vehicle;
Map information storage means in which map information including road sign positions and visual information is recorded;
The road sign search means for searching for the road sign located in the traveling direction from the map information stored in the map information storage device based on the position information acquired by the current position acquisition means. Road sign display device.

(3) The sign information acquisition means includes:
Furthermore, an imaging means for acquiring an image outside the vehicle;
The road sign display device according to (1), further including road sign extraction means for extracting visual information of the road sign from the image acquired by the imaging means.

  (4) The road sign display device according to any one of (1) to (3), wherein the display order determination unit displays the restriction sign with the highest priority.

(5) Furthermore, it has vehicle status acquisition means for acquiring the status of the vehicle,
The display means does not display the road sign when the vehicle status acquired by the vehicle status acquisition means complies with the law indicated by the road sign acquired by the sign information acquisition means (4 The road sign display device according to).

  (6) When the vehicle status acquired by the vehicle status acquisition means does not match the condition indicated by the road sign acquired by the sign information acquisition means, the acquired road sign is displayed with the highest priority (5) The road sign display device described in 1.

According to the first aspect of the present invention, when visual information of a plurality of road signs is acquired, the road signs displayed according to a predetermined display order are displayed. Can be confirmed, and it becomes easy to grasp the contents.
According to invention of Claim 2, the information regarding a road sign is acquired by searching from map information based on a present position. For this reason, road signs that are invisible behind roadside trees and high vehicles ahead, and road signs that have become difficult to see due to bad weather such as fog and rain, and changes in the external environment such as darkness, etc. , Can be surely recognized.

According to the invention described in claim 3, since the visual information of the actual road sign is extracted from the image acquired by the imaging means, the content of the road sign can be displayed based on the road sign that actually exists. .
According to the invention described in claim 4, since the restriction sign is displayed with priority over other signs, it is easy to suppress the restricted vehicle situation in advance.

According to the fifth aspect of the present invention, if the condition of the vehicle matches the condition indicated by the road sign, it is not necessary to display the contents of the sign, so that the display is omitted. As a result, the number of signs to be displayed can be reduced, the contents for displaying the signs can be simplified, and the display contents can be made easier to understand.
According to the invention described in claim 6, when the vehicle situation does not match the condition indicated by the road sign, by notifying the fact, it is possible to suppress violation of laws and regulations in advance. it can. Safer driving operation can be promoted.

Hereinafter, in the road sign display device of the present invention, a preferred embodiment will be described in detail with reference to FIGS.
(1) Outline of the present embodiment In the present embodiment, in a vehicle equipped with a navigation system, information relating to a road sign is acquired by a camera during traveling, or searched from information stored in the navigation system, and the road sign is obtained. Is displayed to the driver.

  At this time, when a plurality of road signs are acquired, the display order is determined based on a predetermined priority order, and the road signs are used as a display device. The predetermined priority order is determined in the order of importance when the driver performs a driving operation. For example, the order of priority is determined in the order of a road sign indicating contents regulated by law, a road sign to call attention to a person, a change in road condition, a notice road sign, a guide sign, and the like. By displaying road signs with high importance preferentially, in other words, by omitting display of road signs with low importance, it is possible to convey information on road signs that are easy to grasp for the driver at a glance. It becomes easy.

  For example, when there is a restriction sign in the acquired road sign, it is displayed with the highest priority, and a restriction violation is suppressed in advance. Furthermore, if the vehicle traveling speed, turn signal, vehicle size (vehicle width, vehicle height, etc.) are acquired and the conditions for displaying the road sign are met, for example, a road sign indicating the speed limit is acquired. In such a case, when the traveling speed is within the speed limit, a road sign indicating the vehicle width restriction is acquired, and when the vehicle width is within the speed limit, the display is not performed. In addition, when a road sign prohibiting entry is acquired and a vehicle enters or is about to enter, a right turn prohibition road sign is acquired and the left turn signal is activated, and the priority order to display Raise the to alert the driver more.

(2) Details of the embodiment
FIG. 1 is a block diagram showing a configuration of a road sign display device 1 mounted on a vehicle. The road sign display device 1 includes a route guidance processing unit 101, a map database 102, a guidance priority determination unit 103, a road sign position database 103a, a sign display priority database 103c, a display history storage unit 103d, a road A sign recognition processing unit 104, a matching road sign pattern database 104a, a GPS (Global Positioning System) 111 as a current position detection unit, a vehicle information detection unit 112, and a camera 113 as an imaging unit The display device 114 and the audio output device 115 are provided.

  The route guidance processing unit 101 includes a processing unit including a CPU, a program storage unit for storing a program for performing route search processing, a RAM as a working area, and the like. The route guidance processing unit 101 performs route search, extraction of data related to road signs, and the like based on the data acquired from the map database 102 and the data acquired from the GPS 111. The route search is a process of searching the map database 102 for a travel route from the current position acquired by the GPS 111 to the purpose set by the driver and determining the route. In addition, in the extraction of data related to road signs, in principle, when it is assumed that the vehicle goes straight, when the data of road signs existing on the straight road is extracted, the turn signal ON is If it is supplied, when it is turned in the blinking direction of the blinker at the nearest intersection or turn, the data of the road sign located in the traveling direction is extracted, or the route determined by the route search process is If it is fixed, a road sign located on the route may be extracted. The route guidance processing unit 101 constitutes a road sign search means.

The map database 102 uses a large-capacity storage medium such as a CD-ROM, DVD-ROM, hard disk drive, etc., and stores intersection data, road data, road data files, and node data files. Road network data consisting of node data is stored. Map information storage means is constituted by the map database.
The guidance priority order determination unit 103 determines a priority order for displaying road signs on the display device 114 when a plurality of road signs are acquired. This order is set in advance for each road sign, and is recorded in a sign display priority database 103c described later as a sign display priority database as a table (see FIG. 2) for determining the priority order.
The display history database records the contents, time, and position of road signs displayed in the past.

  The road sign position database 103a includes road sign position data, attribute of each sign (for example, whether it is a regulation sign, an instruction sign, a warning sign? / Restrictions to make a vehicle state: Vehicle height restrictions, vehicle width restrictions / restrictions on vehicle behavior: for example, entry prohibition, left or right turn prohibition, temporary stop, u-turn prohibition, overtaking prohibition, parking stop / prohibition / pedestrians who call attention to pedestrians Notes: For example, this pedestrian crossing, school zone / other notes that call attention (for example, railroad crossings, under construction, falling rocks, etc.), design of signs as visual information, and the like. The stored road sign includes the road sign displayed on the road surface.

In the sign display priority database 130c, a map for determining a priority order for displaying a road sign is recorded. FIG. 2 shows an example of road signs classified by priority. In principle, the display of the restriction sign has the highest priority, the warning sign, the instruction sign, and the guidance sign have the highest priority, and the guidance sign has the lowest priority. In addition, signs that do not target the vehicle, that is, signs that are displayed for pedestrians, signs that are displayed for bicycles, and signs that are displayed for motorbikes are classified as signs that are not displayed.
These rankings are classified and stored in 10 levels, with priority 0 being the highest priority and priority 9 being the lowest. A road sign of priority 0 is always displayed or always displayed together with other notification means, and priority 9 is displayed when there is no other sign to be displayed.
In addition, in the following cases, the priority is appropriately raised based on the vehicle situation.

a) There are road signs that are ranked higher based on information obtained from vehicle information. If a regulatory matter displayed on a road sign is violated, the road sign has priority 0 and is always displayed. For example, if you have acquired a road sign with a speed limit of 50 km, if you are traveling at a speed of 50 km or more for a certain period of time, or if you have acquired a road sign indicating vehicle closure, go straight without taking a turn signal If you are acquiring a road sign that prohibits traffic outside the specified direction, and blinking a blinker indicating that you want to steer outside the specified direction, a road sign with a vehicle width limit of 2.5 m If you have acquired a vehicle with a width of 2.5m or more (running speed is not zero), this is actually violating the regulations indicated by the road signs Therefore, the sign is displayed with the highest priority.

b) If the current driving state (traveling speed, whether or not to go straight, etc.) is maintained, the ranking is also increased when it is determined that there is a high possibility of violating the regulations displayed on the road sign (for example, In some cases, priority 1). For example, when a road sign prohibiting entry is acquired, the priority is set to 1 when the vehicle goes straight without taking out the blinker. If a turn signal that prohibits turning is acquired and the blinker in the right direction blinks, the possibility of turning is increased, so that the priority is raised from 9 to 1. If the stop road sign is acquired, if the vehicle speed is slow or running, the possibility of stopping is low, so the priority is raised from 4 to 1 because the possibility of violating the regulations increases. It is done. If a road sign indicating vehicle closure is acquired and the vehicle is traveling without stopping, there is a high possibility of violating the regulations, so the priority is raised from 4 to 1.

c) It is also possible to adopt a configuration in which the priority order is raised according to the road condition (traveling environment). For example, in a warning sign, when a road sign such as this is bent, refracted, spelled, slippery, downgraded, etc. is acquired, and the wiper is on, the priority is set to 5 Raise to 2. The fact that the wiper is on is expected to be rainy or snowy, so the road surface is slippery and requires more caution. In addition to the case where the wiper is in the on state, the priority may be raised in the same manner when acceleration is detected by the accelerator sensor.

d) If the road surface is uneven, a warning sign such as a decrease in the number of lanes or a decrease in the width is acquired, the priority may be increased in the same manner when the vehicle speed is equal to or higher than a predetermined value or is accelerated.
e) In the case where road signs such as road surface unevenness, animals may fly out, other dangers, etc. are acquired and the head ride is on, the priority may be raised from 5 to 2. . This is because it is estimated that it is nighttime because the headlights are on, and it is predicted that the need for vigilance is increasing.

f) Road signs that call attention to pedestrians and people involved in construction, such as the school zone, the pedestrian crossing, and road construction, are ranked higher than other warning signs.
g) While the restriction content and the warning content are traveling in the same section, the same restriction content or the warning content sign is not displayed repeatedly or the priority is lowered according to the number of times of display.
For example, a sign indicating prohibition of overtaking acquired a predetermined number of times or more and a speed restriction sign having the same speed lower the display order. Note that the number of display times is determined based on the display history.

h) Items restricted by the time zone are not displayed outside the time zone.

For example, when the current time is 21:00, a road sign indicating parking prohibition from 8:00 to 20:00 is not displayed even if it is acquired.
i) The priority is changed depending on the speed.
The parking prohibition sign is given higher priority when the vehicle is stopped or slowing down, and is lowered during traveling.
j) If the vehicle does not correspond to the vehicle type subject to the road sign, the priority is lowered or not displayed.
For example, a road sign that regulates a large vehicle is not displayed to a driver driving a normal passenger car.

h) If the restricted area changes, the priority is raised at the changed point.
For example, at the point where the area of “maximum speed 50 km / h” is started, the priority of the road sign “maximum speed 50 km / h” is increased. In addition, even when the “highest speed 50 km / h” area ends, the priority of the “highest speed 50 km / h” road sign is raised, and when the area ends, the “highest speed 50 km / h” road A sign is displayed. In addition, if the “maximum speed of 30 km / h” area is started from the “maximum speed 50 km / h” area, the “maximum speed 50 km / h” area ends and the “maximum speed 50 km / h” area ends. Since the "30 km / h" zone is started, both ranks are raised. For the maximum speed, vehicle width, vehicle height, and minimum speed, the priority may be raised only in the newly started area in the case of changing points where the numerical values to be changed change.
If a plurality of priorities can be given to one road sign, the highest priority is determined.

In the display history database 103d, the road sign displayed on the display device 114, the displayed time, and the vehicle position at the displayed time are recorded in the display order in the past.
The road sign recognition processing unit 104 extracts a road sign image from the image supplied from the camera 113 provided toward the outside of the vehicle. Then, the extracted image is compared with the road sign pattern recorded in the matching road sign pattern database 104a, and the pattern closest to the extracted road sign image is used as the extracted road sign. 103.

The guidance priority determination unit 103 refers to the attribute of the road sign recorded in the road sign position database 103a based on the visual information of the road sign supplied from the road sign recognition processing unit 104, and determines the priority from the attribute. To do. The road sign recognition processing unit 104 functions as a road sign extraction unit.
For example, a CCD (Charge Coupled Device) camera is used as the camera 113 and electrically acquires an external image in front of the vehicle. The camera 113 functions as an imaging unit.

The GPS 111 acquires the current position information of the vehicle and supplies the acquired information to the route guidance processing unit 101. The GPS 111 constitutes current position acquisition means.
The vehicle information detection unit 112 includes a vehicle speed sensor that detects a traveling speed of the vehicle, a steering sensor that detects a steering angle, a winker sensor that detects an on state of the winker, an accelerator sensor that detects an accelerator depression amount, and a brake depression amount. It has a brake sensor to detect, a light sensor to detect the on state of the headlight, a wiper sensor to detect the on state of the wiper, and further, such as vehicle width, vehicle height, front and rear width of the vehicle, vehicle weight, vehicle type, displacement, etc. A vehicle information storage unit for storing vehicle information is provided.

From the vehicle information detection unit 112, the traveling speed, the steering angle, the blinker on state, the accelerator depression amount, the brake depression amount, the headlight on state, the wiper on state, the vehicle width, the vehicle height, the front and rear width of the vehicle, The vehicle weight, vehicle type, and exhaust amount are supplied to the guidance priority determination unit 103 via the route guidance processing unit 101.
The display device 114 is configured by a liquid crystal display screen, for example, and displays a design of a road sign. Further, the order of priority is rearranged and displayed by the guidance priority order determination unit 103. The display device 114 constitutes display means.
The voice output device 115 outputs the route guidance information supplied from the route guidance processing unit 101 by voice, and it is expected that the regulation indicated on the road sign displayed on the display device 114 is violated or violated. If it does, it will output a voice and call attention.

The processing contents of the road sign display device 1 configured as described above will be described based on the flowchart shown in FIG.
The initial setting value is referred to (step S101). Vehicle body information (for example, vehicle width, vehicle height, vehicle body length, vehicle type, weight, etc.) and other initial set values are set. The vehicle body information is acquired from the vehicle information detection unit 112. Current position data is acquired from the GPS 111 (step S103).

  Image data is captured from the camera 113 (step S105). Further, with reference to the map database 102, information on road signs located within a predetermined distance in the vehicle traveling direction from the current position acquired in step S103 is extracted (step S107). Here, the range of the predetermined distance is a distance at which the road sign can be grasped visually by the driver, for example, a road sign existing within a range of about 200 to 50 m ahead. The range to be extracted and the distance from the vehicle to the range are changed according to the speed of the vehicle, and both the range and the distance become longer as the speed increases and are set shorter as the speed decreases. If the travel route is determined by the route guidance processing unit 101, the road sign that is located on the travel route is extracted from the road sign extracted in step S107. Therefore, for example, if the route turns right at an intersection, a road sign that appears when the vehicle goes straight or turns left is not extracted. If the travel route has not been determined, a route expected to pass when the vehicle travels straight in accordance with the road regulations is estimated, and a road sign located on the route is extracted.

  The image data acquired by the camera recognition (step S111) is supplied to the road sign recognition processing unit 104. The road sign processing unit 104 extracts a portion that seems to correspond to a road sign from the supplied image data. Then, the extracted image data and the pattern recorded in the matching road sign pattern database 104a are compared, the road sign having the pattern closest to the extracted image data is selected, and the selected road sign is acquired. The information is supplied to the guidance priority determination unit 103 as a sign. At this time, the time when the image data was acquired and the size of the road sign are attached to the supplied road sign data. When a plurality of road sign data is acquired by the camera according to this time and size, it is used for determining the priority. When a plurality of road signs are acquired, the closest sign has a higher priority, but the distance from the vehicle to the road sign is determined by the size of the acquired road sign.

As described above, the latest road sign information that is not recorded in the map database 102 can be obtained by photographing the road sign that actually exists by the camera 113 and obtaining visual information about the road sign from the image. it can. Steps S105 and S107 constitute a sign information acquisition unit.
In step S105 and step S107, it is determined whether or not a road sign has been acquired (step S109). If it has not been acquired, the following processing is not performed and the process returns. If it has been acquired, the traveling speed of the vehicle is acquired from the vehicle information detection unit 112 (step S111). Based on the vehicle speed, it can be determined whether the vehicle is stopped, traveling slowly, traveling, or traveling within the speed limit.

  Furthermore, driver operation data is acquired from the vehicle information detection part 112 (step S113). The driver operation data includes, for example, a steering angle, presence / absence of brake depression, accelerator depression amount, left or right turn signal on / off, headlight on / off, and wiper on / off. Based on the steering angle, it can be determined whether the vehicle is going to turn right or left. It is possible to determine whether or not the vehicle is decelerating based on a change in the brake depression amount. Whether the turn signal is blinking or not can be determined whether left turn, right turn or lane change is going to be made.

Whether the vehicle is running in the dark can be determined by turning on and off the headlight. In addition, weather such as rain or snow can be estimated by turning on / off the wiper. Depending on the situation, the headlight and the wiper can determine whether or not the driver cannot easily see the road sign, and the data table shown in FIG. Based on this, the priority order displayed on the display device 114 may be changed.
In step S117, priorities 0 to 9 are assigned to the acquired road signs. Further, when a plurality of priorities assigned based on the data table shown in FIG. 2 are set for one road sign, the one with the highest priority is assigned as the priority.

Next, the display history is acquired from the display history database 103d (step S115). The road sign displayed on the display device 114 in the past, the time when the display was performed, and the vehicle position where the display was performed are acquired.
A data table (FIG. 2) for determining the priority order recorded in the sign display priority database 103c is acquired (step S117). It is determined whether the number of acquired road signs is (N + 1) [N is a natural number] or more (step S119). If it is not N + 1 or more, road signs are sequentially displayed on the display device 114 in accordance with the priority order, except for signs that need not be displayed (step S121). If N + 1 or more, N road signs with the highest priority are extracted (step S123).

N road signs are displayed on the display device 114 according to the priority order (step S125). At the same time, the displayed road sign is recorded in the display history database 103d (step S127). After the above processing is completed, the process returns to the main routine. The above-described steps S117 to S125 constitute display order determining means.
Based on FIGS. 4-6, the effect | action of the road-sign display apparatus 1 of this invention is demonstrated. 4 to 6 are schematic views showing roads and road signs arranged along the roads, and are schematic views showing the display screen 114S of the display device 114 arranged in the cockpit of the vehicle for each traveling position. FIG.

  In FIG. 4, when the vehicle traveling forward is traveling within the speed limit within the speed limit of 50 km / h at the travel position p1, the road sign A1 “+ road crossing” and “maximum speed” When the road sign A2 of “50 km / h” is acquired, only the road sign a1 of “+ road intersection exists” is displayed. The road sign of “maximum speed 50 km / h” has a display history from the display history, and the vehicle speed is kept below 50 km / h, so the road sign of “maximum speed 50 km / h” is displayed on the screen Not. When the road sign B1 of “parking prohibited from 8:00 to 20:00” is acquired at the travel position p2, it is not expected to stop from the vehicle speed acquired in step S111 from the vehicle information detection unit 112. Nothing is displayed on the display screen 114S.

  At the travel position p3, when the road sign C1 of “prohibited traveling outside the specified direction (right)” and the road sign C2 of “with traffic light” are acquired, the road sign C1 is 4, based on the data table of FIG. The road sign C2 is 5, and the priority order is determined. On the screen 114S, for example, a high priority sign may be set in advance on the left side. By determining in this way, it is possible to inform the driver of the importance of the sign at the displayed position.

  At the traveling position p4 that has reached the intersection, when the route determined by the route search is a right turn or when the right turn signal is blinking, nothing is displayed on the screen. In addition, if no blinker is blinking, the vehicle is expected to go straight, so the road sign D1 for “No traffic” that is expected to violate the regulations when going straight is given priority 1. The image d1 is displayed on the screen 114S. The road sign D1 information may be acquired by the camera 113 or extracted from the map information database 102.

When the left turn signal is blinking at the traveling position p4, it is expected to turn left. In the case of a left turn, there is a road sign E1 of “prohibited entry”, so it is expected to be a violation of regulations. Therefore, the priority order of the road sign E1 is changed to 1 and displayed on the screen 114S.
Here, for example, if it is determined that the vehicle has actually turned to the left based on the steering angle acquired in step S113 from the vehicle information detection unit 112, the law is violated, and the priority of the road sign E1 increases to zero. The road sign e1 is always displayed on the screen 114S.
At the driving position p5, when the road sign F1 with “backward bending to the right” and the road sign F2 with “maximum speed 50 km / h” are acquired, the speed limit does not change, so the priority of the road sign F2 is lowered. Only the road sign f1 is displayed.

At the driving position p6, when the road sign G1 of “easy to slide”, the road sign G2 of “no overtaking” and the road sign G3 of “maximum speed 50 km / h” are acquired, the speed limit of the road sign G3 changes. In addition, since the traveling speed is 50 km / h or less, the priority order is lowered and is not displayed on the screen 114. Further, since the “prohibit overtaking” section is started, the priority is raised, and the sign g2 is displayed on the screen 114S. The “easy to slide” road sign G1 is a warning sign, and two signs g1 and g2 having a high priority are displayed.
At the driving position p7, when the road sign H1 of “easy to slide” and the road sign H2 of “maximum speed 30 km / h” are acquired, the maximum speed limit has changed, so it becomes a change point of regulation, and the priority is raised. A road sign h2 is displayed together with the sign h1.

  Next, another display example will be described with reference to FIG. When the road sign I1 indicating the end of the “no overtaking” area and the road sign I2 of “maximum speed 50 km / h” are obtained at the driving position p8, the road sign I1 is given priority because it is a sign indicating a change point of regulation. The rank is raised, and the signs i1 and i2 are displayed on the screen 114S. When the road sign J1 of “priority road” is acquired at the traveling position p9 that is before the intersection, the instruction sign is in principle priority 6, but no other sign is acquired, so the priority road sign j1 Is displayed on the screen 114S.

  Turn right at the intersection and at the driving position p10 in front of the bridge, obtain a "pause" road sign K1, a "two-way traffic" road sign K2, and a "maximum width 2.2m" road sign K3 Then, the signs k1 and k2 having the priorities of 4 and 5 are displayed on the screen 114S. Further, since the vehicle width acquired in step S113 is less than the maximum width regulated by the road sign K3, the priority is lowered and the road sign K3 is not displayed. If the vehicle speed is monitored and the vehicle does not stop, the priority is further increased to the sign k1.

  At the travel position p11 that has passed through the bridge, the road sign L1 of “width reduction”, the road sign L2 of “maximum speed 50 km / h”, and the road sign L3 of “largest speed 30 km / h” of a large vehicle are acquired. Since the vehicle type acquired in step S113 is not a large vehicle, the priority order of the road sign L3 of “maximum speed 30 km / h” of the large vehicle is lowered and is not displayed on the screen 114S. As for the road sign L2 of “maximum speed 50 km / h”, since there is a display history in the past, the priority is lowered and is not displayed, and among these three signs, the highest priority “width reduction” is displayed. Only the road sign l1 is displayed on the screen 114S.

  Next, another display example will be described based on FIG. When the “pause” road sign M1, the “pedestrian crossing” road sign M2, and the “national road number” road sign M3 are acquired at the travel position p12, the priority m is the sign m1 and the instruction sign. The design m1 and m2 are displayed on the screen 114S with priority given to the road sign M2 of “pedestrian crossing”, which is a sign for calling attention to humans. When you get a road sign N1 with a maximum speed of 50 km / h, a road sign N2 with a railroad crossing, and a road sign N3 with a school, kindergarten, or nursery, at a travel position p13 that turns left on a T-junction. The speed limit has changed because of joining a new road, the priority of road sign N1 with “maximum speed 50 km / h” has increased, and the priority of road sign N3 with “school, kindergarten, nursery school” has become 2 These signs n1 and n3 are displayed on the screen 114S.

When the road sign Q1 “with railroad crossing” is acquired at the travel position p14, the priority is increased and the sign q1 is displayed on the screen 114S when the vehicle is not stopped or slowed down from the vehicle speed acquired in step S111. Is done. Further, when the depression of the brake is detected, the priority order may be lowered or the display may be turned off.
At the driving position p15 that has passed the crossing, the road sign R1 “School, kindergarten, nursery is present”, the road sign R2 “maximum speed 50 km / h” and the road sign R3 “parking prohibited” are obtained. Since the limit has not changed, the road sign of “maximum speed 50 km / h” is not displayed. Further, since there is a low possibility of parking because the vehicle is running, the road sign “parking prohibited” is not displayed, and only the road sign r1 “school, kindergarten, daycare” is displayed on the screen 114S.

It is a block diagram which shows the structure of the road sign display apparatus of this invention. It is a data table which shows the priority which displays a road sign. It is a flowchart which shows the effect | action of a road sign display apparatus. It is a model which shows the content of the road sign displayed with advancing of a vehicle. It is a model which shows the content of the road sign displayed with advancing of a vehicle. It is a model which shows the content of the road sign displayed with advancing of a vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Road sign display apparatus 101 Route guidance process part 102 Map database 103 Guidance priority determination part 103a Road sign position database 103c Sign display priority database 104 Road sign recognition process part 111 GPS
112 Vehicle information detection unit 114 Display device

Claims (6)

Sign information acquisition means for acquiring visual information of a road sign located in the traveling direction of the vehicle;
When there are a plurality of pieces of sign information acquired by the sign information acquisition means, display rank determination means for determining the display rank according to a predetermined rank;
A road sign display device comprising: display means for displaying visual information of road signs in accordance with the order determined by the display order determining means. The sign information acquisition means includes
Current position acquisition means for acquiring the current position of the vehicle;
Map information storage means in which map information including road sign positions and visual information is recorded;
The road sign search means for searching for a road sign located in the traveling direction from map information stored in the map information storage device based on the position information acquired by the current position acquisition means. Road sign display device. The sign information acquisition means includes
Furthermore, an imaging means for acquiring an image outside the vehicle;
The road sign display device according to claim 1, further comprising road sign extraction means for extracting visual information of the road sign from the image acquired by the imaging means.   The road sign display device according to any one of claims 1 to 3, wherein the display order determining means displays the restriction sign with the highest priority. Furthermore, it has a vehicle status acquisition means for acquiring the status of the vehicle,
The display means does not display the road sign when the vehicle situation acquired by the vehicle situation acquisition means complies with the law indicated by the road sign acquired by the sign information acquisition means. The road sign display device described in 1.   The road according to claim 5, wherein when the vehicle status acquired by the vehicle status acquisition means does not match the condition indicated by the road sign acquired by the sign information acquisition means, the acquired road sign is displayed with the highest priority. Sign display device.

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