JP7774333B2 - Driver assistance devices - Google Patents

Description

The present invention relates to, for example, driver assistance devices, etc.

Patent Document 1 listed below discloses a navigation device that searches for and provides guidance along a route to a set destination. This navigation device includes a storage unit that stores map information including search data, a signal determination unit that determines the type of traffic signal at an intersection based on intersection data included in the search data, and a display control unit that displays a traffic signal mark corresponding to the determined type of traffic signal on the screen of a display unit.

Japanese Patent Application Laid-Open No. 2005-326306

Even when drivers look at a screen displaying traffic signal light marks corresponding to different types of traffic signals, it is difficult for them to understand how to apply that information to their driving. The object of the present invention is to provide a driver assistance device that can provide drivers with information that should be applied to their driving.

(1) A driver assistance device that is mounted on a vehicle and used may have a processing means that has the function of referencing a storage means that stores intersection attributes, including intersection location information and information about the traffic lights installed at the intersection, and outputting to an output means information about traffic lights at intersections that are located within a predetermined search range based on the current position of the vehicle and that have special traffic lights that are different from normal traffic lights.

The driver of the vehicle can learn about special traffic lights installed at intersections within a specified search range from the information output to the output means. Before reaching an intersection with a special traffic light, the driver can increase their attention and mentally review the traffic rules to follow when passing through the intersection. This can alleviate the anxiety that drivers feel when driving on unfamiliar roads in unfamiliar areas. It can also help drivers avoid traffic violations and accidents. In this way, the driver assistance device can provide guidance that helps drivers follow traffic rules.

Normal traffic lights and special traffic lights that are different from normal traffic lights should be able to be defined arbitrarily. For example, a normal traffic light should be a type of traffic light that a novice driver or a driver with average knowledge of traffic rules can see and not be confused about whether or not it is okay to enter an intersection, and that is unlikely to lead to a mistake. Alternatively, a normal traffic light should be a type of traffic light that is recognized as a common traffic light by the average driver. Alternatively, traffic lights may be classified as normal traffic lights and special traffic lights based on the number of traffic lights installed. Traffic lights that are more special than normal traffic lights should be classified as special traffic lights.

For example, traffic lights can be classified as either normal or special traffic lights based on static or dynamic information about the traffic lights. Static information can include, for example, the traffic light's shape, appearance, and number of lights. Dynamic information can include, for example, the order in which the lights change their lighting state. Special traffic lights can include, for example, traffic lights with special shapes and special state transitions.

In addition, traffic lights with a large number of installed traffic lights may be classified as normal traffic lights. For example, the number of installed traffic lights for each type of traffic light can be calculated, and traffic light types with a number of installed traffic lights above a reference level can be classified as normal traffic lights. The reference level can be set to, for example, the average number of installed traffic lights. Alternatively, traffic lights may be classified as normal traffic lights or special traffic lights based on the cumulative relative frequency of the number of installed traffic lights when traffic lights are sorted in order of the number of installed traffic lights. For example, traffic lights whose cumulative relative frequency reaches a predetermined percentage can be classified as special traffic lights. If there is a large change in the number of installed traffic light types, it is advisable to review the types that are determined to be normal traffic lights. Traffic lights of types that are not included in the normal traffic lights category can be classified as special traffic lights.

For example, arrow-type traffic lights can be classified as special traffic lights that differ from normal traffic lights. Many arrow-type traffic lights in Japan have only a right-turn arrow light in addition to green, yellow, and red lights. Therefore, such traffic lights can be classified as normal traffic lights and excluded from guidance. This can prevent the output means from outputting too much information. Traffic lights that include arrow lights other than a right-turn arrow light, or traffic lights that include arrow lights in two or more directions, can be classified as special traffic lights.

Even if the installed lights are normal, if the traffic light has a special state transition, it should be classified as a special traffic light. Examples of traffic lights with special state transitions include pedestrian and vehicle separation traffic lights and time-difference traffic lights. There are also traffic lights that do not have a state where the green light is lit, and indicate whether or not you can enter the intersection by only lighting the arrow light. Such traffic lights should also be included in the category of traffic lights with special state transitions. Furthermore, at some intersections it is always possible to turn left. Such intersections should also be included in the category of intersections with traffic lights with special state transitions.

Intersection location information and information about the traffic lights installed at the intersection can be associated and stored as intersection attributes in a storage device. The storage device can be, for example, a non-volatile memory built into the device, or a removable storage medium. Alternatively, an external database server can be used as the storage device, with the driver assistance device receiving database information via a communication device. Intersections whose intersection attributes are to be stored in the storage device can be, for example, all intersections in Japan that have traffic lights installed. Alternatively, the intersections can be limited to intersections on major roads (general national highways, major regional roads, and general prefectural roads).

Current location information for a vehicle equipped with a driver assistance device may be obtained, for example, from a built-in GPS receiver. Alternatively, the driver assistance device may obtain current location information from a GPS receiver equipped in the vehicle via a wireless or wired interface.

The specified search range does not necessarily have to include the current location, but it can be, for example, a certain range including the current location, or the route the vehicle is estimated to be traveling. For example, the search range can be the area within a circle of a specified radius centered on the vehicle's current location. The specified radius can be, for example, 500 meters to several kilometers.

As output means, for example, a speaker that outputs sound, a display device that displays images, etc. may be used. When displaying an image, it is preferable to display an image that shows the appearance of a special traffic light.

The processing means may have a function of searching for a recommended route to the destination and causing the output means to output information indicating the recommended route. If the searched recommended route includes an intersection with a special traffic light, the processing means may cause the output means to output, together with the recommended route, a message informing the driver that the recommended route includes an intersection with a special traffic light.

(2) It is preferable that the driver assistance device include traffic light-related information output by the output means, which includes attention-calling information that notifies the driver that caution is required at the special traffic light.

By noticing the warning information, drivers can enter or stop before an intersection without hesitation when they reach an intersection equipped with special traffic lights. For example, drivers can increase their attention or mentally review traffic rules before an intersection. In this way, the system can help drivers avoid violations and accidents even when driving in unfamiliar areas.

In addition, if a stop is specified at an intersection without traffic lights, the processing means may cause the output means to output a message informing the driver that a stop should be made. Information indicating whether or not a stop is specified at an intersection may be included in the intersection attributes.

When outputting the warning information as audio, it is advisable to output audio that alerts the driver, such as, "There is an arrow-type traffic light within XX km. Please be careful." If the traffic light has a special state transition, it is advisable to have the output means output specific information about how the traffic light will transition as warning information.

For example, there have been cases where a driver sees the straight-line arrow light and mistakenly determines that a left turn is permitted, even when the red light is on, the straight-line arrow light is on, and the straight-line pedestrian signal is green, and ends up making a left turn. To prevent such misjudgments by drivers, it is advisable to notify the driver that only the straight-line arrow light is on and that a left turn is not permitted.

Furthermore, because the meaning of flashing red or flashing yellow traffic lights is easily misunderstood, it is advisable to classify such traffic lights as special traffic lights. For example, when the flashing yellow light is on, you can proceed while being careful of other traffic and do not necessarily need to slow down. Slowing down unconditionally at an intersection with a flashing yellow light can increase the risk of being hit by a vehicle behind. Also, when the flashing red light is on, you can stop at the stop line and proceed after checking that it is safe around you. Violations such as slowing down without stopping at an intersection with a flashing red light are common. Drivers should be notified of the meaning of the flashing red or flashing yellow light before approaching an intersection where a flashing red or flashing yellow light is installed. For traffic lights that flash only at night, it is advisable to include information indicating the time periods during which the light will flash in the intersection attributes. The processing means should classify traffic lights that flash only at night as special traffic lights only during the time periods during which the light will flash.

If the processing means has the function of searching for a recommended route to the destination, once the recommended route to the destination has been determined, it may determine whether there are any intersections with special traffic lights on the recommended route, and if there are any intersections with special traffic lights, it may notify the driver of information that they should be aware of when passing through those intersections.

For example, the display device of the output means may display a map so that the recommended route can be recognized, and an icon may be displayed at a location on the map corresponding to an intersection where a special traffic light is installed. The icon may be designed so that the driver can see what type of traffic light is installed. If there are a large number of intersections to be displayed, some of the intersections where a special traffic light is installed may be displayed in order of proximity to the current location. For example, a message may be output by voice saying, "There is an arrow-type traffic light on the route that requires caution. Please be careful." Furthermore, when driving along the recommended route and approaching an intersection where a special traffic light is installed, a message may be output by voice saying, "There is an arrow-type traffic light on the route that requires caution. Please be careful."

(3) The processing means may be a driver assistance device that references the intersection attributes stored in the storage means and, for intersections located within the search range that have normal traffic lights, does not cause the output means to output information about traffic lights.

By not outputting information about traffic lights at intersections where normal traffic lights are installed, the amount of information output to the output means is reduced. This makes it easier for drivers to notice intersections where special traffic lights are installed.

(4) The information about traffic lights with intersection attributes stored in the storage means may include identification information that identifies whether the traffic light installed at the intersection is the normal traffic light or the special traffic light, and the processing means may be a driver assistance device that causes the output means to output information about traffic lights at intersections where the special traffic lights are installed based on the identification information.

The processing means can easily determine whether to cause the output means to output information about the intersection's traffic light by referring to the identification information that identifies whether the traffic light is a normal traffic light or a special traffic light.

The identification information may be information that directly identifies whether the traffic light is a normal or special traffic light. For example, the intersection attributes may include an item that identifies whether the traffic light is a normal or special traffic light.

The identification information may be information that indirectly identifies whether the traffic light is a normal or special traffic light. For example, it may be possible to identify whether the traffic light is a normal or special traffic light based on intersection information included in the map data of a typical car navigation system.

(5) The identification information may be provided to a driver assistance device that includes information regarding the presence and number of arrow lights, and the direction of the arrows indicated by the arrow lights.

The processing means can determine whether or not to cause the output means to output information about the traffic lights at the intersection based on information about the presence and number of arrow lights and the direction of the arrows indicated by the arrow lights. For example, a traffic light without any arrow lights can be determined to be a non-special traffic light. A traffic light with one arrow light and an arrow pointing to the right can be determined to be a non-special traffic light. A traffic light with two or more arrow lights can be determined to be a non-special traffic light. A traffic light with one arrow light and an arrow pointing in a direction other than right can be determined to be a non-special traffic light.

The identification information for identifying whether a traffic light is special or not may include information indicating whether or not a streetcar light is installed. Traffic lights equipped with streetcar lights may be classified as special traffic lights. For example, when approaching an intersection equipped with streetcar lights, a message may be displayed to drivers informing them that yellow arrow lights are signals for streetcars and that they should be careful. Pedestrian lights are commonly installed at many intersections, so the presence or absence of pedestrian lights does not need to be included in the identification information for identifying whether or not a traffic light is special or not.

(6) The storage means may be a driver assistance device that does not store information about intersections where normal traffic lights are installed, but stores information about intersections where the special traffic lights are installed.

Since information about the many intersections where normal traffic lights are installed is not stored in the storage means, the increase in storage capacity can be suppressed.

(7) The processing means may be a driver assistance device that sets the search range to a position on a route that the vehicle will pass through when traveling along a road, based on map data, the vehicle's current position, and the vehicle's direction of travel.

A route that is passed when driving along a road is likely to be passed over in the future. If a position on this route is set as the search range, information about intersections on routes that are unlikely to be passed over will be excluded from the search range. As a result, it is possible to prevent too much traffic light information from being output to the output means. The driver can obtain only the information that is deemed most necessary, making it easier for them to notice the information they need.

When the vehicle changes course by turning right, left, or making a U-turn, the processing means may modify the search range to search for intersections where special traffic lights are installed, and cause the output means to output information about the traffic lights at intersections where special traffic lights are installed.

"Following the road" means proceeding along the current route except at intersections, and when entering an intersection, exiting towards the exit road that requires the smallest change in direction.

(8) The intersection attribute of an intersection where a dedicated lane is provided on an approach road to the intersection for heading to a specific exit road includes information about the dedicated lane,
The processing means may be a driver assistance device having a function of searching for a recommended route from the vehicle's current location to the destination, and if there is an intersection on the recommended route where the dedicated lane is provided, notifying the driver of a lane that is easy to enter into the dedicated lane that the vehicle should travel along in order to proceed along the recommended route, just before the point where the dedicated lane starts.

Drivers can learn the recommended lane for entering a dedicated lane before reaching an intersection where the dedicated lane is provided. This reduces the chance of drivers being confused by having to enter a dedicated lane just before an intersection.

Depending on the dedicated lane, it may be possible to enter the intersection even when the red light is on because the arrow light is on. When it is necessary to enter such a dedicated lane to travel the recommended route to the destination, the processing means may cause the output means to output information to notify the driver that the arrow light is on and that it is possible to enter the intersection, even when the red light is on. For example, the driver may be notified to enter the intersection by following the arrow light. This can prevent the driver from mistakenly stopping before the intersection when it is possible to enter the intersection.

At intersections where a dedicated lane for right-turning vehicles is provided and where U-turns are possible, the processing means should notify the driver that a vehicle in front of the vehicle may be making a U-turn. Unlike right-turning vehicles, vehicles making a U-turn may behave in ways that the driver of the following vehicle does not expect. By operating the vehicle while assuming that a vehicle in front of the vehicle may be making a U-turn, the driver can prevent accidents from occurring.

When the vehicle is stopped at the front of a designated lane at an intersection, failure to check the permitted direction of travel for that designated lane can easily lead to a violation. When the vehicle is stopped at the front of a designated lane at an intersection, the processing means can cause the output means to output a message urging the driver to proceed in the designated lane's direction of travel. The determination of whether the vehicle is at the front of a designated lane can be made, for example, based on an image captured by a camera capturing an image of the area ahead of the vehicle. A camera can be built into the driver assistance device to acquire this image data. Alternatively, the driver assistance device can acquire image data from an on-board camera. The determination of whether the lane the vehicle is in is a designated lane can be made by extracting road markings from the image captured by the camera. Furthermore, as the accuracy of GPS positioning improves, it will also be possible to determine the lane the vehicle is in from the GPS positioning results.

(9) The processing means may be a driver assistance device that has the function of searching for advance warning signs installed on a route that the vehicle will pass through when traveling along a road, based on information that can identify the location of the advance warning signs, map data, the vehicle's current position, and the vehicle's direction of travel, and notifying the driver that the advance warning sign is installed just before the location where the advance warning sign is installed.

If a driver notices an advance warning sign too late, they may not have enough time to read the sign's contents. When a driver is notified that an advance warning sign has been installed, they can become aware of the sign's presence just before reaching the location where the sign is installed. This allows them to read the sign's contents in ample time.

Information that can identify the location where the advance warning sign is installed may be stored in a storage means that stores intersection attributes. The processing means may output the information displayed on the advance warning sign to an output means. For example, an image of the advance warning sign may be displayed on a display device of the output means. Even if the driver misses the opportunity to check the content of the advance warning sign, they can still understand the content of the advance warning sign from the information output to the output means.

If a recommended route to the destination has been set, the processing means may notify the driver that advance notice signs have been installed on the recommended route.

The advance notice sign to be notified may be one that provides information about an intersection where a special traffic light is installed, for example.

The inventions described in (1) to (9) above can be combined in any manner. For example, it is possible to have at least one of the other configurations (2) to (9) without all or part of the configuration (1). However, it is particularly preferable to have all or part of the configuration (1) and at least one of the configurations (2) to (9). Furthermore, any of the components described in (1) to (9) may be extracted and combined. The applicant intends to obtain patent rights for such configurations as well.
The specific aspects of the present invention described above are merely examples, and some of them may be expanded or limited.

The driver of the vehicle can learn about special traffic lights installed at intersections within a specified search range from the information output to the output means. Before reaching an intersection with a special traffic light, the driver can increase their attention and mentally review the traffic rules to follow when passing through the intersection. This can alleviate the anxiety that drivers feel when driving on unfamiliar roads in unfamiliar areas. It can also help drivers avoid traffic violations and accidents. In this way, the driver assistance device can provide guidance that helps drivers follow traffic rules.

FIG. 1A is a schematic perspective view of a driver assistance device according to a first embodiment, and FIG. 1B is a block diagram of the driver assistance device according to the first embodiment. FIG. 2 is a diagram showing data items of intersection attributes. Figure 3A is a diagram showing an example of the appearance of an arrow-type traffic light that also serves as a tram traffic light, Figure 3B is a diagram showing an example of the appearance of a time-difference traffic light, and Figure 3C is a diagram showing an example of the appearance of a pedestrian-vehicle separation traffic light. FIG. 4A is a diagram showing an example of an image displayed on the display device of the driver assistance device according to the first embodiment, and FIG. 4B is a diagram showing the correspondence between icons displayed on the display device and the meanings of those icons. FIG. 5 is a diagram showing an example of an image displayed on the display device of the driver assistance device according to the second embodiment. FIG. 6 shows an image displayed on the display device when the vehicle approaches an intersection where an arrow-type traffic light, which is classified as a special traffic light, is installed. FIG. 7 is a diagram showing a route that the vehicle will take when traveling along a road from the current position of the vehicle. FIG. 8 is a plan view showing an example of an approach road to an intersection where a dedicated lane is provided. FIG. 9 is a plan view showing another example of an approach road to an intersection where a dedicated lane is provided. FIG. 10 is a schematic diagram of a warning guide sign and a driver assistance system for explaining the function of the driver assistance system according to the fourth embodiment. FIG. 11 is a diagram showing an example of a map of an area in which the zone 30 is set.

[First Example]
A driver assistance device according to a first embodiment will be described with reference to FIGS. 1A to 4C.
1A is a schematic perspective view of a driver assistance device according to a first embodiment. The driver assistance device 1 is mounted on a vehicle for use. The driver assistance device 1 is supported on the dashboard of the vehicle, for example, via a cradle 2. The bottom surface of the cradle 2 is attached to the dashboard of the vehicle, thereby fixing the driver assistance device 1 to the dashboard.

A display device 3 is provided on the front surface of the driver assistance device 1 (the surface facing the rear of the vehicle (driver's side)). The display device 3 may be, for example, a liquid crystal display or an organic EL display. A touch panel 4 serving as an input device is provided on the surface of the display device 3. The vehicle user can issue various commands to the driver assistance device 1 by operating the touch panel 4.

A card insertion slot 5 is provided on the side of the driver assistance device 1. A memory card 6 serving as a removable storage medium is inserted into the driver assistance device 1 through the card insertion slot 5. The memory card 6 can be, for example, an SD memory card or a micro SD memory card.

Figure 1B is a block diagram of a driver assistance device 1 according to the first embodiment. The processing unit 10 includes a central processing unit (CPU) 11, a random access memory (RAM) 12, and a read-only memory (ROM) 13. The CPU 11 executes programs stored in the ROM 13 to realize various functions of the driver assistance device 1. A storage area for temporary data when the CPU 11 executes the programs is reserved in the RAM 12.

The GPS receiver 15 calculates the vehicle's current position (latitude and longitude). The processing unit 10 reads the vehicle's current position data calculated by the GPS receiver 15. The processing unit 10 communicates data with external devices via the communication device 16. The communication device 16 may be, for example, one that complies with short-range wireless communication standards or one that uses a mobile communication network. The driver assistance device 1 may not be equipped with a GPS receiver, and the vehicle's current position information may be received via the communication device 16 from a GPS receiver installed in the vehicle.

The output means 17 includes a display device 3 and a speaker 7. The processing unit 10 causes the display device 3 to display information such as images and text, and causes the speaker 7 to output voice or sound. Various commands are input to the processing unit 10 when the vehicle user operates the touch panel 4.

A memory card 6 is inserted into the memory card reader 18. The processing unit 10 can read, rewrite, and write data stored on the memory card 6. The memory card 6 stores intersection attributes for each intersection, including location information for that intersection and information about the traffic lights installed at that intersection.

Figure 2 shows the data items for intersection attributes. Intersection attributes include intersection location information, traffic light identification information, state transition type information, and information on the number of arrow lights for each connecting road, arrow direction information, and information indicating the presence or absence of streetcar lights.

Intersection location information indicates the location of the intersection. The intersection location is expressed, for example, as latitude and longitude. Traffic light identification information is information used to identify whether the traffic light is a normal traffic light or a special traffic light.

Normal traffic lights and special traffic lights that are different from normal traffic lights can be defined arbitrarily. For example, a normal traffic light could be a type of traffic light that a novice driver or a driver with average knowledge of traffic rules would see and would not be confused about whether or not to enter an intersection, and would not be likely to mistaken for another. Alternatively, a normal traffic light could be a type of traffic light that would be recognized as a common traffic light by the average driver. Alternatively, traffic lights could be classified as normal or special based on the number of traffic lights installed. Traffic lights that do not fall under the category of normal traffic lights could be classified as special. For example, traffic lights that are more special than normal traffic lights could be classified as special traffic lights. The traffic light identification information item has a pre-set value of "normal" or "special" based on one of the various definitions described above, or a combination of these definitions.

State transition type information indicates the type of transition between traffic light states. Traffic lights equipped with normal green, yellow, and red lights transition between green, yellow, and red states in that order. For traffic lights with special state transitions, information about the state transition is stored in the state transition type information field. Examples of traffic lights with special state transitions include time-difference traffic lights, pedestrian-vehicle separation traffic lights, and traffic lights that do not light green and only use arrow lights to indicate progress.

The information on the number of arrow lights for each connecting road indicates the number of arrow lights installed on the traffic lights that vehicles entering the intersection from that connecting road should refer to. The information on arrow direction indicates the direction of the arrow indicated by the arrow lights installed on the traffic lights that vehicles entering the intersection from that connecting road should refer to. The information on the presence or absence of tram lights literally indicates whether or not tram lights are installed.

Next, an example of a special traffic light will be described with reference to FIGS. 3A to 3C.
3A is a diagram showing an example of the appearance of an arrow-type traffic light that also serves as a streetcar traffic light. This traffic light includes a green light, a yellow light, a red light, a right-turn arrow light, a straight-through arrow light, a left-turn arrow light, and a streetcar light. Some arrow-type traffic lights do not include a streetcar light, some include only one arrow light, some include two arrow lights, and some include four or more arrow lights.

Figure 3B shows an example of the appearance of a time-difference traffic light. This traffic light includes a green light, a yellow light, a red light, and a sign indicating that it is a time-difference traffic light.

Figure 3C shows an example of the appearance of a pedestrian-vehicle separation traffic light. This traffic light includes a green light, a yellow light, a red light, and a sign indicating that it is a pedestrian-vehicle separation traffic light.

Next, the processing of the processing unit 10 will be described with reference to FIGS. 4A and 4B.
The processing unit 10 (FIG. 1B) has a function of referring to the contents of the memory card 6 and displaying, on the display device 3, information about traffic lights at intersections that are located within a predetermined search range based on the current position of the vehicle and that have special traffic lights that are different from normal traffic lights. For intersections that have normal traffic lights, information about traffic lights is not displayed.

Whether or not a traffic light is special can be determined based on the traffic light identification information (Figure 2) of the intersection attributes. The predetermined search range may be, for example, the inside of a circle (search circle) of a predetermined radius centered on the current position of the vehicle. The radius of the search circle may be, for example, within a range of 500 m to 3 km. The radius of the search circle may also be varied depending on the traveling speed of the vehicle. The faster the traveling speed, the longer the radius of the search circle.

Figure 4A is a diagram showing an example of an image displayed on the display device 3 (Figures 1A and 1B). The position of the vehicle is indicated by an inverted V-shaped icon 20. The direction indicated by the icon 20 corresponds to the direction ahead of the vehicle. The direction ahead of the vehicle can be obtained, for example, from an electronic compass built into the driver assistance device 1. The position of an intersection where a special traffic light is installed is indicated by an icon (image) 21 corresponding to the type of traffic light. Circles with radii of 500 m, 1 km, and 2 km are displayed with the vehicle's position as the center.

Figure 4B shows the correspondence between icons 20, 21 and their meanings. For example, an icon 20 representing the vehicle itself and icons 21 representing arrow-type traffic lights, flashing traffic lights, tram traffic lights, time-difference traffic lights, and pedestrian-vehicle-separated traffic lights are defined.

Furthermore, the processing unit 10 causes the speaker 7 to output voice alert information informing the driver that caution is required for special traffic lights within the search range. For example, it is preferable to output voice alerting the driver, such as "There is an arrow-type traffic light within XX km. Please be careful." If the traffic light has a special state transition, it is preferable to output voice alert information from the speaker 7 that specifically describes how the traffic light will transition.

Next, we will explain another example of how to classify traffic lights into normal traffic lights and traffic lights that are more specialized than normal traffic lights.

For example, traffic lights can be classified as either normal or special traffic lights based on static or dynamic information about the traffic lights. Static information can include, for example, the traffic light's shape, appearance, and number of lights. Dynamic information can include, for example, the order in which the lights change their lighting state. Special traffic lights can include, for example, traffic lights with special shapes and special state transitions.

In addition, traffic lights with a large number of installed traffic lights may be classified as normal traffic lights. For example, the number of installed traffic lights for each type of traffic light can be calculated, and traffic light types with a number of installed traffic lights above a reference level can be classified as normal traffic lights. The reference level can be set to, for example, the average number of installed traffic lights. Alternatively, traffic lights may be classified as normal traffic lights or special traffic lights based on the cumulative relative frequency of the number of installed traffic lights when traffic lights are sorted in order of the number of installed traffic lights. For example, traffic lights whose cumulative relative frequency reaches a predetermined percentage can be classified as special traffic lights. If there is a large change in the number of installed traffic light types, it is advisable to review the types that are determined to be normal traffic lights. Traffic lights of types that are not included in the normal traffic lights category can be classified as special traffic lights.

For example, arrow-type traffic lights can be used as special traffic lights that differ from regular traffic lights. Many arrow-type traffic lights in Japan have only a right-turn arrow light in addition to green, yellow, and red lights. Therefore, such traffic lights can be classified as regular traffic lights and excluded from guidance. This can prevent the output of too much information from the output means 17 (Figure 1B). Traffic lights that include arrow lights other than a right-turn arrow light, or traffic lights that include arrow lights in two or more directions, can be classified as special traffic lights.

Even if the installed lights are normal, if the traffic light has a special state transition, it should be classified as a special traffic light. Examples of traffic lights with special state transitions include pedestrian and vehicle separation traffic lights and time-difference traffic lights. There are also traffic lights that do not have a state where the green light is lit, and indicate whether or not it is possible to enter an intersection by only lighting the arrow light. Such traffic lights should also be included in the category of traffic lights with special state transitions. Furthermore, at some intersections, it is always possible to turn left. Such intersections should also be included in the category of intersections with traffic lights with special state transitions.

[Effects of the First Embodiment]
Next, the excellent effects of the first embodiment will be described.
The driver of the vehicle can learn about special traffic lights installed at intersections within a predetermined search range from the information output to the output means 17 (FIG. 1B). When attention alert information is output from the speaker 7, the driver can easily notice the existence of intersections where he or she should drive carefully. Before reaching an intersection with a special traffic light, the driver can increase his or her attention and mentally review the traffic rules when passing through the intersection. This can relieve the driver's anxiety when driving on a road for the first time in an unfamiliar area. It can also help the driver avoid traffic violations and accidents.

For example, there have been cases where a driver sees the straight-line arrow light and mistakenly determines that a left turn is permitted, even when the red light is on, the straight-line arrow light is on, and the straight-line pedestrian signal is green, and ends up making a left turn. If only the straight-line arrow light is on and the driver is notified as a warning that a left turn is not permitted, this type of misjudgment by the driver can be prevented.

In the first embodiment, for intersections where normal traffic lights are installed, information about the traffic lights is not displayed on the display device 3 (Figures 1A and 1B), thereby reducing the amount of information displayed on the display device 3. This makes it easier for drivers to notice the existence of intersections where special traffic lights are installed.

By providing a traffic light identification information item in the intersection attributes (Figure 2) to identify whether a traffic light is normal or special, the processing unit 10 can easily determine whether a traffic light at an intersection within the search range is one that should be displayed on the display device 3 (whether it is a traffic light that should be guided). Furthermore, by changing the setting value of the traffic light identification information item, information about the traffic lights at each intersection can easily be included in or excluded from the items to be displayed on the display device 3.

[Modification of the first embodiment]
Next, various modifications of the first embodiment will be described.
In the first embodiment, the intersection attributes ( FIG. 2 ) for each intersection are stored in the memory card 6 ( FIGS. 1A and 1B ), but they may also be stored in various other storage means. For example, they may be stored in the ROM 13 of the processing unit 10. Also, an external database server may be used as the storage means. The driver assistance device 1 may receive information about intersections from the database server via the communication device 16. For example, information about intersections within a certain area centered on the current location of the vehicle may be received and temporarily stored in the RAM 12 ( FIG. 1B ).

Intersections whose intersection attributes are to be stored in a storage means such as the memory card 6 may be, for example, all intersections in the country that have traffic lights. They may also be limited to intersections on main roads (general national highways, major regional roads, and general prefectural roads). By changing the traffic light identification information item (Figure 2) among the intersection attributes stored in the storage means from "normal" to "special," or vice versa, the intersection can be easily included in or excluded from the output targets to the output means 17.

The intersection attributes (Figure 2) may not include a traffic light identification information item, and the processing unit 10 may indirectly determine whether a traffic light is a normal or special traffic light based on information about the presence and number of arrow lights and the direction of the arrow indicated by the arrow lights. For example, a traffic light without any arrow lights may be determined to not be a special traffic light. A traffic light with one arrow light and an arrow pointing to the right may be determined to not be a special traffic light. A traffic light with two or more arrow lights may be determined to be a special traffic light. A traffic light with one arrow light and an arrow pointing in a direction other than the right may be determined to be a special traffic light. If the map data of a car navigation system includes information such as the number of arrow lights at an intersection, the processing unit 10 will be able to determine whether a traffic light installed at an intersection is a normal or special traffic light based on such map data from the car navigation system.

The identification information for identifying whether a traffic light is special or not may include information indicating whether or not a tram light is installed. Traffic lights equipped with tram lights may be classified as special traffic lights. For example, when approaching an intersection equipped with tram lights, a message may be displayed to the driver saying, "Please be careful as yellow arrow lights are tram signals." Pedestrian lights are commonly installed at many intersections, so the presence or absence of pedestrian lights does not need to be included in the identification information for identifying whether or not a traffic light is special or not.

Because the meaning of flashing red or flashing yellow traffic lights is easily misunderstood, it is advisable to classify such traffic lights as special traffic lights. For example, when the yellow light is flashing, you can proceed while being careful of other traffic and do not necessarily need to slow down. Slowing down unconditionally at an intersection with a flashing yellow light may increase the risk of being hit by a vehicle behind. Also, when the red light is flashing, you can stop at the stop line and proceed after checking that it is safe around you. Violations such as slowing down without stopping at an intersection with a flashing red light are common. Before an intersection where a flashing red or flashing yellow light is installed, it is advisable to notify drivers of the meaning of the flashing red or flashing yellow light. For traffic lights that flash only at night, it is advisable to include information indicating the time period during which the light will flash in the intersection attributes. The processing means should classify traffic lights that flash only at night as special traffic lights only for the time period during which the light will flash.

In the first embodiment, a circular area centered on the vehicle's current position was used as the search range for determining whether or not an intersection with a special traffic light is present, but the search range does not necessarily have to include the vehicle's current position. For example, a semicircular area located in front of the vehicle could be used as the search range. In this way, information about the area behind the vehicle, which is unlikely to be passed through, will not be displayed on the display device 3 (Figures 1A and 1B), making it easier for the driver to notice useful information.

In the first embodiment, information about intersections where normal traffic lights are installed is stored in the storage means, but information about intersections where normal traffic lights are installed does not need to be stored in the storage means. In this way, information about the many intersections where normal traffic lights are installed is not stored in the storage means, which can prevent an increase in the capacity of the storage means.

In the first example, the guidance was directed to intersections with special traffic lights, but it would also be good to provide guidance on intersections without traffic lights that require careful driving. For example, it would be good to provide guidance on roundabouts.

[Second Example]
Next, a driver assistance system according to a second embodiment will be described with reference to Fig. 5. Hereinafter, a description of the components common to the driver assistance system according to the first embodiment will be omitted.

In addition to the functions of the driver assistance device 1 of the first embodiment (Figs. 1A and 1B), the driver assistance device 1 of the second embodiment has map data stored in a storage device such as a memory card 6, and the processing unit 10 (Fig. 1B) has the functions of displaying a map of an area including the current location of the vehicle on the display device 3, and searching for a recommended route (recommended route) to the destination and displaying the recommended route on the display device 3.

Once the recommended route is determined, the processing unit 10 searches for intersections with special traffic lights, with positions on the recommended route as the search range. If there is an intersection with a special traffic light on the recommended route, the processing unit 10 causes the output means 17 (Figure 1B) to output a message informing the driver that there is an intersection with a special traffic light on the recommended route.

Figure 5 shows an example of an image displayed on the display device 3. On the map displayed on the display device 3, an S symbol in a circle is displayed at the vehicle's current position, and a G symbol in a circle is displayed at the destination. The recommended route is indicated by a thick solid line. At intersections on the recommended route where special traffic lights are installed, an icon 21 corresponding to the type of special traffic light is displayed.

The processing unit 10 displays a map and an icon 21 on the display device 3, and outputs a message from the speaker 7 indicating that there is an intersection with a special traffic light on the recommended route. For example, it may output a message saying, "There are arrow-type traffic lights, pedestrian-vehicle separation traffic lights, and tram traffic lights on the route that require caution. Please be careful." Furthermore, when driving along the recommended route and approaching an intersection with a special traffic light, it may output a message saying, "There is an arrow-type traffic light coming up that requires caution. Please be careful."

Figure 6 shows an image displayed on the display device 3 when the vehicle approaches an intersection equipped with an arrow-type traffic light classified as a special traffic light. The processing unit 10 causes a partial area 8 of the display screen of the display device 3 (for example, approximately one-third of the left side of the display screen) to graphically display the appearance of the traffic light at the next intersection equipped with a special traffic light, as well as lane information for the approach road to that intersection. Furthermore, the distance to the intersection equipped with that traffic light is displayed numerically. Each lane in the graphic displayed on the display device 3 is marked with an arrow indicating the permitted direction of travel when entering the intersection from that lane. Area 8, which graphically displays the appearance of the traffic light and lane information for the approach road to that intersection, may also be displayed in other areas of the display screen, such as the upper left area, the upper right area, or approximately one-third of the right side.

The timing for displaying the appearance of the traffic light and the lane information for the approach road to the intersection as a graphic should be when the distance to the intersection reaches a predetermined distance, for example, 1 km. This predetermined distance should be changed depending on the legal speed limit for the currently traveling route or the current vehicle speed. For example, the higher the legal speed limit or current vehicle speed, the longer this predetermined distance should be.

The processing unit 10 also highlights the lane in which the vehicle should travel in order to proceed along the recommended route, among the graphics showing the lanes of the approach road displayed on the display device 3. For example, the lane in which the vehicle should travel within the graphics may be colored differently from the other lanes, or the lane in which the vehicle should travel may be displayed brighter than the other lanes.

The processing unit 10 may also display the appearance of the traffic lights displayed in area 8 so that the lighting status of the traffic lights that allow travel along the recommended route can be recognized. For example, if the recommended route is a route that involves turning right at an intersection, the appearance of the traffic lights with the red light and right-turn arrow light on may be displayed in area 8.

[Effects of the Second Embodiment]
The driver can see the icon 21 on the map displayed on the display device 3 and know where on the route the vehicle is scheduled to travel there is an intersection with a special traffic light that requires caution. When the driver approaches an intersection with a special traffic light, warning information is output by voice, allowing the driver to pay more attention before reaching the intersection or to mentally reconfirm the traffic rules when passing through the intersection.

Intersections other than those on the route the vehicle is planning to travel will not be displayed on the display device 3, even if they have special traffic lights. Information about intersections other than those on the planned route is of low importance to the driver. Because less important information is not displayed on the display device 3, the driver can more easily notice information of high importance.

The driver can review in advance in their mind the specific points to be aware of when passing through an intersection by looking at the outline of the traffic light and the lane information of the approach road displayed in a partial area 8 (Figure 6) on the display screen of the display device 3.

[First Modification of the Second Embodiment]
Next, a first modification of the second embodiment will be described.
In the second embodiment shown in FIG. 5, the driver is guided to intersections where special traffic lights are installed on the recommended route to the destination, but in this modified example, useful guidance is provided to the driver even when a recommended route is not set.

The processing unit 10 (Figure 1B) sets the search range to the positions on the route that the vehicle will pass when traveling along a road, based on map data, the vehicle's current position, and the vehicle's direction of travel. If there is an intersection with a special traffic light on the route that the vehicle will pass when traveling along a road, the processing unit 10 displays an icon corresponding to the traffic light at the intersection's location on the map.

When the vehicle changes course by turning right, left, or making a U-turn, the processing unit 10 may modify the search range and re-display on the display device 3 information about traffic lights at intersections where special traffic lights are installed.

Next, the "follow the road" operation will be described with reference to FIG.
"Follow the road" means to follow the route you are currently traveling on except at intersections. At intersections, it means to go straight. When entering an intersection where there is no straight exit road, it means to exit towards the exit road with the smallest change in direction.

Figure 7 shows a route 26 that the vehicle will take when traveling along a road from its current position 25. There is no straight-through exit road at intersection 27. The angle θ1 at which the direction of travel is changed when heading towards exit road 28 is smaller than any of the angles θ2, θ3, and θ4 at which the direction of travel is changed when heading towards other exit roads. Therefore, traveling towards exit road 28 corresponds to "traveling along a road."

A route that is passed when driving along a road is likely to be passed over in the future. If a position on this route is set as the search range, information about intersections on routes that are unlikely to be passed over will be excluded from the search range. As a result, it is possible to prevent too much traffic light information from being displayed on the display device 3. The driver can obtain only the information that is deemed most necessary, making it easier to notice the information they need.

[Second Modification of Second Embodiment]
Next, a second modification of the second embodiment will be described.
In the second embodiment, the processing unit 10 notifies the driver of intersections where special traffic lights are installed and information about the traffic lights, but in this modification, the processing unit 10 notifies the driver of intersections where no traffic lights are installed and a stop is mandatory. For example, the processing unit 10 outputs a voice message from the speaker 7 informing the driver that a stop should be made before an intersection where a stop is mandatory. Information indicating whether or not an intersection requires a stop may be included in the intersection attributes and stored in a storage unit.

In this modified version, drivers will be aware that they are approaching an intersection where they are required to stop, making them less likely to violate the stop sign.

[Another Modification of the Second Embodiment]
Next, another modification of the second embodiment will be described.
When the processing unit 10 (FIG. 1B) detects that the vehicle has stopped at an intersection before the intersection where the special traffic light is installed, it is preferable that the processing unit 10 notify the driver by voice that the vehicle will soon approach the intersection where the special traffic light is installed. The driver who notices this voice can obtain specific information about the special traffic light by looking at the display screen of the display device 3 while the vehicle is stopped.

In addition, it is a good idea to display information about special intersections in text form along with traffic light and lane graphics so that the passenger in the front seat can look at the display device 3 and convey information about special intersections to the driver. For example, a message such as "The traffic light at the intersection XXX meters ahead is equipped with arrow lights for right turns, going straight, and turning left. The rightmost lane is a right-turn-only lane" can be displayed on the display device 3. Even if the passenger does not have a driver's license, they can still convey the necessary information to the driver by reading aloud the text displayed on the display device 3.

It would be ideal if the destination input operation and the operation of selecting one destination from the candidate destinations could be done by voice.

[Third Example]
Next, a driver assistance system according to a third embodiment will be described with reference to Figures 8 and 9. Hereinafter, a description of the components common to the first and second embodiments will be omitted.

The intersection attributes referenced by the driver assistance device in this embodiment include information about dedicated lanes for intersections where dedicated lanes are provided for heading toward specific exit roads. Similar to the second embodiment, the processing unit 10 (Figure 1B) has the function of searching for a recommended route from the vehicle's current location to the destination. If there is an intersection on the recommended route where a dedicated lane is provided, the processing unit 10 has the function of notifying the driver of a lane that is likely to enter the dedicated lane before the point where the dedicated lane begins, as a recommended lane, in order to proceed along the recommended route.

Figure 8 is a plan view showing an example of an approach road to an intersection where dedicated lanes are provided, and a diagram showing the appearance of traffic lights as seen from the approach road. Approach road 32 to intersection 31 increases from three lanes to four lanes just before the intersection, where the dedicated lanes begin. Of the four lanes, the rightmost lane is a right-turn-only lane, and the leftmost lane is a lane for going straight and turning left. The second and third lanes from the left are straight-only lanes. The traffic lights installed at intersection 31 include a right-turn arrow light.

If a route that makes a right turn at intersection 31 is set as the recommended route, processing unit 10 (Figure 1B) notifies the driver of a preferred lane (recommended lane) for entering the dedicated right-turn lane just before point 33 where the dedicated lane begins. For example, processing unit 10 causes speaker 7 (Figure 1B) to output a voice message saying, "A dedicated right-turn lane will be coming soon. Please drive in the lane on the right."

When the vehicle passes point 33 where the dedicated lane begins, processing unit 10 notifies the driver of things to be careful of when passing through intersection 31. For example, processing unit 10 causes speaker 7 to output a voice message saying, "Please follow the right turn arrow signal."

If a route that makes a left turn at intersection 31 is set as the recommended route, processing unit 10 (Figure 1B) notifies the driver of a preferred lane for entering the left turn lane before point 33 where the dedicated lane begins. For example, processing unit 10 causes speaker 7 (Figure 1B) to output a voice message saying, "A left turn lane will be coming soon. Please stay in the left lane." Once the vehicle passes point 33 where the dedicated lane begins, processing unit 10 causes speaker 7 to output a voice message saying, "Please follow the left turn arrow signal."

Because it is possible to go straight at the intersection 31 regardless of which lane the vehicle is traveling in before the point 33 where the dedicated lane begins, if a route that goes straight is set as the recommended route, the processing unit 10 (Figure 1B) does not output any particular warning message.

Figure 9 is a plan view showing another example of an approach road to an intersection with dedicated lanes. The approach road 36 to the intersection 35 increases from three lanes to four lanes just before the intersection, where the dedicated lanes begin. Of the four lanes, the rightmost lane is a dedicated right-turn lane, the leftmost lane is a dedicated left-turn lane, and the two central lanes are dedicated straight-through lanes. The traffic lights installed at the intersection 35 include arrow lights for right turns, straight turns, and left turns.

If a route going straight through intersection 35 is set as the recommended route, processing unit 10 (Figure 1B) notifies the driver of the preferred lane (recommended lane) for going straight through intersection 35 just before point 37 where the dedicated lane begins. For example, processing unit 10 outputs a voice message from speaker 7 (Figure 1B) saying, "The road will split into lanes for turning right and left and going straight. Please stay in the center or right lane to go straight."

When the vehicle passes point 37 where the dedicated lane begins, processing unit 10 notifies the driver of things to be careful of when passing through intersection 35. For example, processing unit 10 causes speaker 7 to output a voice message saying, "Please follow the green light or the arrow signal for going straight ahead."

If a route that involves a right turn at intersection 35 is set as the recommended route, processing unit 10 (Figure 1B) notifies the driver of the preferred lane for turning right at intersection 35 just before point 37 where the dedicated lane begins. For example, processing unit 10 causes speaker 7 (Figure 1B) to output a voice message saying, "A dedicated right-turn lane will be coming soon. Please stay in the lane on the right."

When the vehicle passes point 37 where the dedicated lane begins, the processing unit 10 causes the speaker 7 to output a voice message such as, "Please follow the arrow signal for a right turn."

If a route that involves a left turn at intersection 35 is set as the recommended route, processing unit 10 (Figure 1B) notifies the driver of the preferred lane for turning left at intersection 35 just before point 37 where the dedicated lane begins. For example, processing unit 10 causes speaker 7 (Figure 1B) to output a voice message saying, "A dedicated left-turn lane will be coming soon. Please drive in the left lane."

When the vehicle passes point 37 where the dedicated lane begins, for example, the processing unit 10 causes the speaker 7 to output an audible message saying, "Please follow the green light or left-turn arrow signal."

[Effects of the Third Embodiment]
Next, the excellent effects of the third embodiment will be described.

In the example shown in Figure 8, when turning right at intersection 31, the driver is prompted to stay in the right lane just before point 33 where the dedicated lane begins. By changing lanes to the right, the driver can more easily enter the dedicated right-turn lane after the additional lanes are added. Furthermore, by being warned to follow the right-turn arrow signal, the driver can perform driving operations without confusion just before intersection 31.

In the example shown in Figure 9, when going straight through intersection 35, the driver is prompted to stay in the center or right lane just before point 37 where the dedicated lane begins. By changing lanes from the leftmost lane to the center lane, the driver can avoid entering the dedicated left-turn lane. Furthermore, by being warned to follow green lights or arrow signals for going straight, the driver can perform driving operations without confusion just before intersection 35.

Furthermore, when turning right at intersection 35, if a driver is prompted to drive in the rightmost lane just before point 37 where the dedicated lane begins, the driver may change lanes to the rightmost lane, thereby avoiding a situation where the driver remains in the leftmost or center lane and is unable to enter the dedicated right-turn lane. Furthermore, by being warned to follow the arrow signal for a right turn, the driver can perform driving operations without confusion just before intersection 35.

Furthermore, when turning left at intersection 35, if a driver is prompted to drive in the leftmost lane just before point 37 where the dedicated lane begins, and changes lanes to the leftmost lane, it is possible to avoid a situation where the driver remains in the rightmost lane and does not have enough room to enter the dedicated left-turn lane. Furthermore, by being warned to drive according to green lights or left-turn arrow signals, the driver can perform driving operations without confusion just before intersection 35.

For example, just before the start of a right-turn lane, there may be warning signs such as "Right turn lane in 150m," "Right turn lane in 100m," and "Right turn lane in 50m," as well as warning signs above each lane of the road that indicate the direction of travel for the right-turn lane. However, drivers may overlook these warning signs. In the third embodiment, even if a driver overlooks the warning sign informing them of the right-turn lane, they can learn the recommended lane for entering the right-turn lane just before the lane begins. Once the driver reaches the point where the right-turn lane begins, they can enter the right-turn lane without hesitation. This reduces the occurrence of situations where drivers are confused about entering a right-turn lane just before an intersection.

Depending on the dedicated lane, it may be possible to enter the intersection even when the red light is on because the arrow light is also illuminated. When it is necessary to enter such a dedicated lane to travel the recommended route to the destination, the processing unit 10 may output information from the speaker 7 to notify the driver that the intersection is accessible because the arrow light is illuminated, even when the red light is on. For example, as shown in the examples of Figures 8 and 9, the driver may be notified to enter the intersection by following the arrow light. This can prevent the driver from mistakenly stopping the vehicle before the intersection when it is possible to enter the intersection.

The point at which the recommended lane is notified to the driver should be set so that there is sufficient distance between the point at which the recommended lane is notified to the driver to enter the dedicated lane and the point at which the dedicated lane begins to allow the driver to complete the lane change. For example, the point should be set 250 m to 1 km before the point at which the dedicated lane begins.

If the road just before the point where the dedicated lane begins has two lanes, it is easy for the driver to determine which lane to use when turning right, going straight, or turning left at the next intersection. If the road just before the point where the dedicated lane begins has three or more lanes, the driver may be confused about which lane to use. The third embodiment has a more pronounced effect when the road just before the point where the dedicated lane begins has three or more lanes.

[Modification of the third embodiment]
Next, a modification of the third embodiment will be described.
In the example shown in Fig. 8, the processing unit 10 outputs a voice message from the speaker 7 saying, "Please follow the right turn arrow signal." In addition to the voice output, it is also possible to display the lighting status of a traffic light that allows a right turn on the display device 3. For example, it is possible to display the appearance of a traffic light with the red light and right turn arrow light both lit.

In the example shown in Figure 9, in addition to outputting audio, the processing unit 10 may cause the display device 3 to display the appearance of the traffic light with the green light on, and the appearance of the traffic light with the red light, straight arrow light, and left turn arrow light on.

At intersections where a dedicated lane for right-turning vehicles is provided and U-turns are possible, the processing unit 10 may alert the driver that a vehicle in front of the host vehicle may be making a U-turn. Unlike right-turning vehicles, vehicles making a U-turn may behave in a way that is unexpected by the driver of the following vehicle. By operating the vehicle while assuming that a vehicle in front of the host vehicle may be making a U-turn, the driver can reduce the occurrence of accidents.

At intersections where U-turns are prohibited, it is a good idea to have a message output by voice from speaker 7 informing the driver that U-turns are prohibited.

When the vehicle is stopped at the front of a designated lane at an intersection, failure to check the permitted direction of travel for that designated lane can easily lead to a violation. When the vehicle is stopped at the front of a designated lane at an intersection, the processing unit 10 (Figure 1B) can output a message from the speaker 7 urging the driver to proceed in the designated lane's direction of travel. The determination of whether the vehicle is at the front of a designated lane can be made, for example, based on an image captured by a camera capturing an image of the area ahead of the vehicle. A camera can be built into the driver assistance device to acquire this image data. Alternatively, the driver assistance device can acquire image data from an on-board camera. The determination of whether the lane the vehicle is in is a designated lane can be made by extracting road markings from the image captured by the camera. Furthermore, as the accuracy of GPS positioning improves, it will also be possible to determine the lane the vehicle is in from the GPS positioning results.

If a recommended route is set that requires a left turn at an intersection, a message can be output by voice from the speaker 7 to alert the driver to be careful of being hit by two-wheeled vehicles such as bicycles. This will encourage drivers to be careful when making left turns, thereby reducing the occurrence of hit-and-run accidents.

[Fourth Example]
Next, a driver assistance system according to a fourth embodiment will be described with reference to Fig. 10. Hereinafter, a description of the configuration common to the first and second embodiments will be omitted.

Figure 10 is a schematic diagram of a warning guide sign 40 and the driver assistance device 1 to explain the function of the driver assistance device 1 according to the fourth embodiment. Information that can identify the locations where multiple warning guide signs 40 are installed, as well as map data, is stored in a storage device such as a memory card 6.

When an advance warning sign 40 is installed on a route 41 that is passed when traveling along a road, the processing unit 10 (Figure 1B) has a function of notifying the driver that an advance warning sign 40 has been installed just before the point where the sign 40 is installed. For example, the processing unit 10 may cause the speaker 7 to output an audio message saying "An advance warning sign 40 will be installed soon" just before the point where the sign 40 is installed. For example, if the advance warning sign 40 is installed 400 m before an intersection, a message notifying the driver of the advance warning sign 40 may be output 500 m before the intersection. For example, a message notifying the driver that an advance warning sign 40 has been installed may be output at the point where the sign 40 begins to come into the driver's field of vision.

Furthermore, the processing unit 10 may cause the display device 3 to display the information displayed on the advance notice sign 40. For example, it may cause the display device 3 to display an image of the advance notice sign 40.

[Effects of the Fourth Embodiment]
Next, the excellent effects of the fourth embodiment will be described.
If the driver notices the advance warning sign 40 too late, he or she may not have enough time to read the contents of the advance warning sign 40. When the driver is notified that an advance warning sign 40 has been installed, the driver can notice the presence of the advance warning sign 40 just before the point where the advance warning sign 40 is installed. This allows the driver to read the contents of the advance warning sign 40 in ample time. Furthermore, even if the driver misses the timing to check the contents of the advance warning sign 40, the driver can still understand the contents of the advance warning sign 40 from the information displayed on the display device 3.

For example, if a guide sign such as "Turn right here" is installed, by the time the driver notices the sign, they may have already reached the point where they should turn right and be unable to make the turn. In the fourth embodiment, by notifying the driver of the presence of a guide sign installed at the point where they should change lanes, such as "Turn right here," before they reach that point, the driver will be able to notice the guide sign in plenty of time and change lanes.

When a recommended route to the destination has been set, the processing unit 10 may notify the driver that advance notice signs 40 have been installed on the recommended route. This allows the driver to know where advance notice signs 40 have been installed before traveling along the recommended route. The advance notice signs 40 to be notified may be signs that provide information about intersections with special traffic lights, for example.

[Fifth Example]
Next, a driver assistance system according to a fifth embodiment will be described with reference to Fig. 11. Below, a description of the components common to the first and second embodiments will be omitted.

Figure 11 shows an example of a map of an area where "Zone 30" has been set. Zone 30 is indicated by a dashed line. In the fifth embodiment, information specifying areas where drivers should pay particular attention, such as Zone 30, Silver Zones, and School Zones, is stored in a storage device such as a memory card 6.

When searching for a recommended route to a destination, the processing unit 10 (Figure 1B) provides a search mode that prioritizes searching for routes that do not pass through zone 30. When the search mode is set to a mode that does not pass through zone 30, the processing unit 10 recommends a route that bypasses zone 30 as the recommended route, as shown by the thick line in Figure 11. When the vehicle approaches zone 30, the processing unit 10 notifies the driver that a route that does not pass through zone 30 has been set as the recommended route. For example, the processing unit 10 outputs a voice message from the speaker 7 saying, "You will soon reach zone 30. A route that does not pass through zone 30 will be displayed."

Furthermore, when the processing unit 10 detects that the vehicle has entered an area where the driver is required to exercise particular caution, such as Zone 30, a Silver Zone, or a school zone, it may be configured to notify the driver that the vehicle has entered a caution zone.

If the destination is located within zone 30, the processing unit 10 may search for a recommended route that minimizes the distance traveled within zone 30.

[Effects of the Fifth Embodiment]
In the fifth embodiment, accidents within the zone 30 can be avoided or suppressed by driving around the zone 30 or by driving so as to shorten the distance traveled within the zone 30 .

In the various embodiments described above, the driver assistance device provides the driver with warning information, but the final decision should be made by the driver, who should visually check the traffic signs and urge the driver to follow the traffic signs.

[Other Examples]
When the processing unit 10 (FIG. 1B) outputs a voice message to alert the driver, the processing unit 10 may wait for input of an acknowledgement message from the driver. The acknowledgement message may be input by the driver without taking his/her eyes off the road. For example, the processing unit 10 may recognize that an acknowledgement message has been input by detecting a voice such as "understood" or "OK." Alternatively, the processing unit 10 may recognize that an acknowledgement message has been input regardless of where the driver touches the touch panel 4 (FIGS. 1A and 1B).

If the driver does not input a message indicating that the driver has confirmed the operation during this input waiting state, it is recommended that a warning message be periodically output by voice. If the driver inputs a message indicating that the driver has confirmed the operation, the processing unit 10 should stop the periodic output of the warning message. This can prevent the driver from not noticing the warning message and arriving at an intersection requiring caution. Furthermore, by providing the driver with appropriate warnings, it is also possible to prevent the driver from falling asleep at the wheel.

When stopped at an intersection, if the vehicle ahead is tall, the driver of the vehicle may not be able to see the traffic light. In such cases, if the traffic light is visible from the location where the driver assistance device is installed, it is a good idea to notify the driver of the traffic light status based on images taken by a camera installed in the driver assistance device. For example, an image of the traffic light can be extracted from images captured by the camera and displayed on the display device 3. Even in situations where the driver cannot directly see the traffic light, the driver can find out the status of the traffic light by looking at the display device 3 of the driver assistance device.

While various aspects of the present invention have been described above using examples and modifications, it should be noted that the descriptions of these examples and modifications are provided to aid in understanding the present invention, and are not intended to limit the technical scope of the present invention. The technical scope of the present invention is not limited to the configurations explicitly described in the specification, and this specification also discloses other inventions that can be obtained by combining various aspects of the present invention described. The applicant of this application has specified the configuration of the invention for which a patent is sought in the appended claims, but it is the applicant's intention in the future to include inventions that are not currently specified in the claims but that include at least one component disclosed in this specification within the scope of the claims.

The present invention is not limited to the configuration described in the "Mode for Carrying Out the Invention" above. New inventions may be created by arbitrarily selecting and combining components included in each of the above-described embodiments and variations. Furthermore, new inventions may be created by arbitrarily combining any component of each embodiment or variation with any component described in the "Summary of the Problem" or any component that embodies any component described in the "Summary of the Problem." The applicant of the present application intends to obtain rights to these new inventions through amendments to the present application or divisional applications, etc.

1 Driver assistance device 2 Cradle 3 Display device 4 Touch panel 5 Card insertion slot 6 Memory card 7 Speaker 8 Part of display screen 10 Processing unit 11 Central processing unit (CPU)
12 Random Access Memory (RAM)
13 Read-Only Memory (ROM)
15 GPS receiver 16 Communication device 17 Output means 18 Memory card reader 20 Icon indicating the position of the vehicle 21 Icon indicating the position of an intersection where a special traffic light is installed 25 Position of the vehicle 26 Route to travel along the road 27 Intersection with no straight exit road 28 Exit road with the smallest driving change angle 31 Intersection 32 Approach road to the intersection 33 Point where a dedicated lane starts 35 Intersection 36 Approach road to the intersection 37 Point where a dedicated lane starts 40 Advance notice sign 41 Route

Claims (5)

A driver assistance device mounted on a vehicle,
a processing means having a function of referring to a storage means in which intersection attributes including location information of the intersection and information about the traffic lights installed at the intersection are stored , and causing an output means to output caution information informing a driver that caution is required at an intersection that is located within a predetermined search range based on the current position of the vehicle and that is equipped with at least one of a time-difference traffic light, a pedestrian-vehicle separation traffic light, and a traffic light that does not light green and indicates progress only with an arrow light;
The processing means
When the attention-calling information is output, a state is entered in which a response from the driver informing the driver that confirmation has been completed is awaited, and the attention-calling information is output periodically until the response is input;
A driver assistance device having a function of stopping the periodic output of the attention-calling information when the response is input. The device according to claim 1 , wherein the processing means has a function of outputting the warning information by voice. The driver support device according to claim 1 or 2, wherein the response is a confirmation response message from the driver, and is configured so that the driver can give the response without taking his/her eyes off the road. Further, a driver assistance device including a display,
3. The driver assistance device according to claim 1, wherein the response is made by the driver touching an arbitrary position on the display screen of the display device, and the response is set so that the driver can do so without taking their eyes off the road. A program for causing a computer to implement the functions of the system described in any one of claims 1 to 4.