JP7349756B2 - System and program - Google Patents

Description

TECHNICAL FIELD The present invention relates to a system and a program for notifying information regarding the approach when the current location is in a predetermined proximity relationship with the alarm target.

In recent years, a large number of vehicle speed measuring devices that measure the speed of automobiles have been installed around roads and the like. An example of a vehicle speed measuring device is one that emits microwaves in a predetermined frequency band toward a vehicle and receives reflected waves thereof to measure the traveling speed of the vehicle.

In order to detect the presence of such a vehicle speed measuring device, microwave detectors configured to detect microwaves emitted from the vehicle speed measuring device and output an alarm are conventionally known.

Additionally, some vehicle speed measuring devices cannot be detected by conventional microwave detectors. For example, there is a so-called loop-type system that embeds a loop-shaped coil in the ground and detects when a vehicle passes over the coil and also determines the vehicle speed. There are also devices that detect the speed of a vehicle using light other than microwaves. Therefore, the installation position information of the vehicle speed measuring device is stored in advance, and when the current position obtained by GPS (Global Positioning System) etc. approaches the memorized installation position (when a predetermined approach relationship is reached), There is a vehicle-mounted electronic device such as a radar detector that issues a warning regardless of whether microwaves are detected (Patent Document 1). These various vehicle speed measurement devices are installed at locations where traffic accidents occur frequently or where speeding is likely to occur and are likely to cause traffic accidents, so by notifying drivers in advance of these locations, it is possible to avoid particularly dangerous locations. It can encourage safe driving in compliance with traffic rules.

Specific notification formats include, for example, relative positional relationships such as "1km to the left is the expressway H system" or "immediately ahead is the local road N system", as well as content that specifies the purpose as audio information. They are outputted from a speaker, and characters and images representing them are displayed on a display unit.

In addition, there are various types of warning targets, such as fixed vehicle speed measurement devices, N system (automatic vehicle number reading device), areas where traffic accidents occur frequently, various enforcement areas, and checkpoint areas. You can choose.

By the way, one of the conditions for the registered warning target to be actually warned is that the current position and the position of the warning target are in a predetermined close relationship. Specifically, this approach relationship is determined by determining the straight line distance between the current position and the position of the warning target, and setting the straight line distance to be less than or equal to a set reference value r (for example, 2 km, 1 km, etc.). As a result, alarm targets existing within a circle with radius r centered on the current position are extracted as targets to be actually warned.

At this time, there are often multiple alarm targets around the current location. In such a case, one alarm target that meets a predetermined condition is set as a target object, and alarm information indicating the above-mentioned relative positional relationship and the like is reported for the target object. In addition, if a display unit is provided, an object representing the own vehicle is drawn at a predetermined position on the display screen, and if a warning target exists within the space displayed on the display screen, the object of the warning target is drawn. Draw at the corresponding position on the screen. At this time, an object with a different aspect from other alarm target objects is drawn at the position of the alarm target, which is the target object, so that it can be seen that it is the target object. By changing the way objects are drawn in this way, the driver can recognize the existence of the target warning target from among the multiple warning targets (objects) drawn on the display screen, and can identify the target warning target from among the multiple warning targets (objects) drawn on the display screen. You can know the relative positional relationship.

JP2008-64588A

The proximity relationship, which is one of the conditions for extracting a warning target, is determined based on the straight-line distance between the current position and the position of the warning target. Therefore, for example, if a warning target installed on a road different from the road on which the vehicle is currently traveling is located at a straight-line distance of less than a predetermined distance from the current position, the vehicle will be notified as the warning target. However, since the alert target that was notified is not installed on the road on which the vehicle is currently traveling, the vehicle will not pass in front of the alert target even if the vehicle continues to drive. In other words, this alarm is an unnecessary alarm. Receiving such unnecessary warnings causes the driver to worry unnecessarily. Furthermore, since the driver does not pass in front of the warning target, he or she may not be able to actually find the warning target and confirm that it has passed, which may lead to an uneasy state. In addition, if such different roads are parallel to and relatively close to the road on which you are currently traveling, and if you draw objects on the display screen at the position of your vehicle and the position of the warning target, then Since the object to be warned is drawn, there is a risk that it may be mistakenly recognized that there is a warning object on the road on which the own vehicle is traveling. In particular, when the display screen is small, there is a high possibility of erroneous recognition.

For example, if the road you are driving on has a large curve in front of you and there is a warning target at the end of the bend, you can draw objects on the display screen at the position of your vehicle and the position of the warning target. Then, since the object to be warned is drawn far away from the front in the direction of travel, there is a risk that the driver may mistakenly believe that the object is on a different road than the one they are traveling on at first glance. . Conversely, if the road is currently straight and has a curve in front of it, and there is a warning target on a road that is different from the road you are driving on as an extension of the straight road, your vehicle will appear on the display screen. If you draw objects at the location and the location of the warning target, the warning target object will be drawn ahead in the direction of travel, so there is a risk of erroneously recognizing that the warning target exists ahead of the road you are traveling on. There is. Particularly in the case of low-priced products that do not store map information, the problem of misrecognition increases because a map cannot be displayed when storing the position information of a point to be alerted and displaying the position of that point.

In addition, some devices have a function of notifying the remaining distance to the warning target as the notification content of the warning target. This remaining distance is based on the straight line distance described above. When a vehicle actually travels, it goes without saying that when the road is curved, it may change its course by turning left or right at an intersection along the way. Therefore, the target of the warning is often not on the extension line of the direction in which you are currently traveling, and the degree to which the remaining distance decreases differs from the actual distance traveled. A feeling of discomfort arises.

Furthermore, the distance traveled until actually arriving in front of the warning target is naturally longer than the straight-line distance. As mentioned above, if you repeatedly turn right or left from your current location to actually reach the target of the warning, if the road has a large curve, or if you drive in accordance with the condition of the road network, one-way streets, or other traffic laws, etc. Sometimes the difference can be very large. In this case, the vehicle must travel a long distance and take time to actually arrive at the target of the warning after the first warning is issued. As a result, even though there is a warning, the driver is often unable to visually confirm the target of the warning, and there is a risk that the driver may become suspicious of the warning, or even if the driver misjudges the warning as false. There is also the possibility that a situation that may lead to the subject of a warning may occur. Furthermore, in many cases, the driver does not actually go to the location to be warned, which requires repeated left and right turns to arrive at, and in this case, unnecessary warnings are issued, which is not desirable.

On the other hand, as the number of warning target types to be registered in the database increases, the number of warning targets around the current location also increases, and when all of them are displayed, there are many warning target objects. Another problem is that it becomes difficult to determine the location. In addition, in order to reduce the number of alarm targets to be alerted, the types of alarms to be alerted may be registered in advance, or those that are ahead in the direction of travel and within a fan-shaped area at a predetermined angle may be set as alarm targets.

However, in the former case, if the alarm types are narrowed down more than necessary, it will not be possible to notify the various registered alarm targets. Furthermore, in the latter case, a warning target that exists ahead of a road with a large curve or after turning an intersection may be located outside the fan shape, making it impossible to issue a warning.

As described above, this type of conventional in-vehicle electronic equipment has a problem in that it is not able to adequately extract warning targets existing in the surroundings and issue a warning. In addition, when there are multiple warning targets and detailed warning information for a given warning target (object) is to be reported, there is also the issue of making it easy for the driver to understand which warning target is being notified. be.

In order to achieve the above-mentioned object, an in-vehicle electronic device according to the present invention includes (1) a position acquisition means for acquiring the current position of a vehicle, a current position of the vehicle acquired by the position acquisition means, and a warning target. A system comprising: a control means that performs notification control on the notification means when the position information of the alarm target obtained by accessing the position storage means for storing the position information has a predetermined proximity relationship, the control means , determining a route from the current position of the vehicle to the warning target using the road network information obtained by accessing a map data storage means that stores road network information, and determining whether or not there is an approach relationship based on the determined route. I tried to decide.

The position acquisition means corresponds to the GPS receiver 8 in the embodiment. The position acquisition means of the present invention acquires position information about the current position of the vehicle from an external device/equipment, as well as information acquired by a position detection means that detects the current position such as the GPS receiver of the embodiment. Including those with functions to do so. Examples of such external devices and devices include electronic devices equipped with a position detection function (GPS receiver) such as a car navigation device, and a GPS antenna unit.

The map data storage means corresponds to the database 19 in the embodiment. In this way, some information is built into the device, while some or all of the information is stored in an external device such as a server, and the necessary information is obtained by accessing that server via communication. be.

The route corresponds to a recommended route in the embodiment. This recommended route is preferably one that is commonly used in car navigation systems, and is determined from among the many routes from the current location to the destination, the one with the shortest travel distance or the one that will get you there in the shortest time. do. At this time, the type of road on which the vehicle is traveling (priority road/general road) may be specified and a route that meets the conditions may be determined. In the present invention, such car navigation technology may be used, or the route to the warning target may be determined based on other conditions.

Conventionally, the proximity relationship was determined based on the straight line distance connecting the current position and the warning target, but in the present invention, the determination is made based on the route determined using road network information. Determinations based on the route include, for example, whether the warning target exists beyond the road on which the vehicle is actually traveling or on a different road, and whether it is easy to reach the warning target from the current location. It is better to perform this based on conditions and situations that are more in line with actual driving. In this way, even if there are a large number of registered warning targets around the own vehicle, those that correspond to actual driving are determined to have "a predetermined approach relationship". Therefore, the user can know which alarm target is more appropriate among the many alarm targets that exist around the user's vehicle.

(2) Preferably, the control means calculates the distance traveled along the route, and determines whether or not the approach relationship exists based on the distance. The state of the road network, i.e. whether it is a straight road or a curved road, the location of intersections, traffic rules such as one-way streets and no right turns, etc., determines the straight line distance between the current location and the warning target, and the warning target along the route. The distance traveled up to (traveling distance) will vary. Although this distance is longer than the straight line distance, the difference varies greatly depending on the situation. Even if there is a warning target that is close to the target in a straight line, it may take time to reach the target if it is necessary to drive a long distance by detouring, etc., to reach the target. There is little need to do so, and the possibility of actually going to the location targeted for the warning is also low. On the other hand, it is preferable to issue a warning for a warning target traveling along such a route for a short distance because there is a possibility that the warning target will be reached relatively soon. In this way, by determining the proximity relationship and controlling the alarm based on the distance traveled along the route to reach the alarm target, it is possible to appropriately extract and notify the alarm target to which the alarm should be issued.

(3) The control means may determine the time required to travel the route, and determine whether or not the approach relationship exists based on the time. The time may be calculated using, for example, probe information on traffic congestion obtained through VICS or communication. If it takes a long time to reach the alarm target, the urgency to issue a warning is low, and conversely, if the time is short, the urgency to issue a warning increases. Therefore, it is preferable to determine whether there is a close relationship based on time.

(4) Preferably, the control means determines the number of intersections at which the vehicle turns when traveling along the route, and determines whether or not the proximity relationship exists based on the number. The more intersections there are to turn (right or left) on the route from the current position to the warning target, the more complicated the route will be to reach the warning target. Therefore, it can be said that the more complicated the route, the lower the possibility of actually going to the location targeted for warning. In other words, if the possibility of actually going to the location targeted by the warning is low, even if the straight-line distance etc. is short, it can be said that the distance is not close based on the driving situation at that time (the proximity relationship is low or non-existent). . By determining the approach relationship based on the number of intersections at which the vehicle turns and controlling the warning, it is possible to appropriately extract and notify the warning targets to which the warning should be issued.

(5) In the invention of (4), it is preferable that the control means not issue a regular warning for the warning target for which the number of turning intersections is two or more. For example, if there is a warning target on another road that is parallel (substantially parallel/does not intersect) with the road you are currently driving on, you must deviate from the road you are currently driving on in order to start driving on the other road. Therefore, the vehicle must make one turn at an intersection on the road it is traveling on, and then, in order to enter another road, it must make one turn at the intersection of that other road. Therefore, in order to drive on such another road, it is necessary to turn at an intersection at least twice. In other words, if the person has to turn at an intersection twice or more to reach the warning target, the warning target is on another parallel road or the driver has to take a complicated route to reach the warning target. Unlikely. Therefore, by doing as in the present invention, even if the distance (straight line distance and/or distance when traveling along a route) to the warning target is short, the warning target existing on another parallel road can be effectively detected. can be excluded. Not issuing a regular warning includes not only not issuing a warning, but also issuing a warning but at a lower level. Lowering the level means, for example, drawing an object that is less conspicuous than a normal alarm target at the alarm target position, or drawing an object at the alarm target position but with detailed details attached to the alarm target. Warning information may not be output.

(6) The control means extracts, from the current position and the position information of the warning target, a warning target existing in a circular or fan-shaped area having a radius of a set predetermined distance from the current position as a candidate for the warning target; It is preferable that the route to the extracted alarm target candidate is determined, and the alarm target to be notified by the notification means is determined based on the determined route. By narrowing down the targets for which routes are to be determined, the load on the control means is reduced. The fan-shaped area that serves as a reference for extracting warning target candidates is preferably a fan-shaped area with a radius r and a center angle θ with respect to the traveling direction of the vehicle.

(7) The predetermined distance may be less than or equal to the distance at which the proximity relationship is determined when the presence or absence of the proximity relationship is determined based on the distance traveled along the route. Assuming that the vehicle travels along the road from the current position to the warning target, the distance is equal to or longer than the straight-line distance from the current position to the warning target. Therefore, by setting the predetermined distance to a distance at which a close relationship exists, it is possible to prevent objects that cannot be the warning target to be issued from being extracted as warning target candidates. Furthermore, the travel distance and the straight-line distance are equal when the current position of the vehicle and the warning target are connected by one straight road, and in most cases, the straight-line distance is shorter. Therefore, by setting the predetermined distance shorter than the distance at which a close relationship exists, it is possible to appropriately reduce the number of warning target candidates to be extracted.

(8) In the case of a warning target for which it is better to issue a warning when the warning target approaches from a specific direction, registering direction information indicating the specific direction in association with the warning target in a predetermined storage means; The control means is configured to determine whether to issue a regular warning based on the direction of travel of the vehicle when traveling along the route and on the road where the warning target is installed, and the direction information. It's good to do that.

When a vehicle approaches a warning target, which warning targets should be issued regardless of which direction the vehicle approaches the warning target, and which warning targets should be issued if the vehicle approaches from a specific direction. There are good alarm targets. To give an example, warning targets for which it is better to issue a warning regardless of directionality and approaching from any direction include drowsy driving accident locations, parking surveillance areas, intersection surveillance points, accident-prone areas, and vehicle targets. There are areas where it occurs frequently. On the other hand, in the case of a vehicle monitoring device or system such as a vehicle speed measurement device or N system, there is a monitoring area and a lane to be monitored (up lane/down lane). If the vehicle does not pass through the monitored area or lane, there is little need to issue a warning. The speed limit switching point is also the point where the speed limit switches to the lower side, so it is usually set on one side of the up lane or the down lane, so if you are driving in the opposite lane and approaching the target of the warning. There is little need to issue an alarm. In this way, if whether or not to issue a warning changes depending on the direction in which the warning target is approached, by registering direction information for specifying the approaching direction in association with the warning target, When the vehicle travels along the route and finally arrives just in front of the warning target, if the direction of travel of the vehicle at that time and the direction specified by the direction information registered in the warning target do not have the desired relationship. , it is possible to prevent a regular alarm from being issued.

In other words, when direction information is registered, what is important is not the relationship with the direction of travel of the vehicle at the current location, but the direction of travel of the vehicle immediately before the warning target. In the present invention, since there is road network information and the traveling direction of the vehicle immediately before the warning target is known, there is an appropriate relationship between the direction specified in advance by the direction information of the warning target and the traveling direction of the vehicle immediately before the warning target. It is possible to determine whether or not this is the case, and to issue the correct warning.

Note that the storage means for registering this direction information may be the same as (incorporated into a part of) the position storage means, or may be separate from it. This storage means may also be implemented in a device equipped with a control means, or may be realized as a storage device such as a server outside the device. This specific direction corresponds in embodiments to the installation direction. In other words, since the specific direction is set based on the direction in which the device is installed (the direction that specifies the monitoring area), in the embodiment, the installation direction is set based on the case where the alarm target is the device. However, this does not preclude the specification of specific directions for alarm targets other than equipment.

(9) In the case of a warning target for which a warning should be issued when the warning target approaches from a specific direction, registering direction information indicating the specific direction in association with the warning target in a predetermined storage means; For the route, on a road where there is a warning target for which direction information has been set, it is preferable to select a route that proceeds in the installation direction as the direction to approach the warning target. By doing so, it is possible to exclude routes that approach the alarm target in a direction different from the originally specific direction.

(10) The control means controls the alarm according to the remaining distance to a predetermined alarm target, and the remaining distance is the distance traveled from the current position to the predetermined alarm target along the route. It is recommended to set the following. This type of system displays the remaining distance to the warning target using numerical values or indicators, changes the background color of the display, or notifies the remaining distance by voice. In this case, by using the travel distance, it is possible to issue a warning based on the remaining distance at an appropriate timing that more closely matches the actual situation.

(11) The notification means includes a display section, and the control means draws a road map based on the road network information on the display section, and displays the current position on the road map and the location of the warning target. Corresponding objects may be drawn, and a guide line connecting the object representing the own vehicle drawn at the current position and the object representing the warning target may be drawn along the determined route. Since the guide line is drawn along the road, the driver can understand at a glance whether the route to the warning target is the road he or she is trying to drive on, and whether or not there is a warning target to be careful of. It can be understood intuitively. Further, the guide line may be more conspicuous if it is drawn as an animation, for example, gradually extending from the vehicle's position along the road and finally reaching the object to be warned. In addition, the guide line only needs to know the positional relationship between the current position and the warning target, and the tip of the guide line does not need to be directly connected to the object indicating the own vehicle and the object indicating the warning target. .

(12) The notification means includes a display unit, and the control unit draws a display board on the display unit that displays information regarding the warning target, and when there are multiple warning targets, the plurality of warning targets It is advisable to draw the display boards for each alarm target so that the one with the highest priority is on the front side. This is preferable because the existence of multiple alarm targets and their order can be understood at a glance.

(13) The program of the present invention is a program for causing a computer to realize the function of the control means in the in-vehicle electronic device described in any one of (1) to (12) above.

According to the present invention, it is possible to extract alarm targets that have a high possibility of actually becoming the alarm target, appropriately narrow down the surrounding alarm targets for alarm/notification, and issue a warning for the narrowed down alarm targets. . By narrowing down the warning targets to be alerted, for example, even if the position of the warning target is shown on the display, the number of displayed warning targets is small, making it easier for the driver to confirm each warning target.Furthermore, by devising the drawing, When notifying detailed warning information about a predetermined warning target (object), the driver can easily understand which warning target is being notified.

1 is a diagram showing the configuration of a radar detector that is a preferred embodiment of the present invention. FIG. 2 is a block diagram of a radar detector. It is a figure which shows the example of a display of a standby screen, a radar scope, and a GPS warning. It is a figure which shows the example of a display of the warning screen in a radar wave warning function. It is a figure which shows an example of the own vehicle position and the warning target which exists in the surroundings. FIG. 6 is a diagram showing search results of recommended routes to each warning target candidate. It is a figure showing the relationship between the installation direction set as a warning target, and the traveling direction of a vehicle. It is a figure showing an example of a display screen. It is a figure showing an example of a display screen. It is a figure explaining a function. It is a figure showing an example of a display screen.

FIGS. 1 and 2 show the configuration of a radar detector, which is a preferred embodiment of the electronic device constituting the system of the present invention. This radar detector is usually mounted on the dashboard. As shown in Fig. 1, this radar detector has a solar panel 2 and a switch section 3 arranged on the top surface of a case body 1, and transmits microwaves in the frequency band emitted by a speed measuring device inside the front side of the case body 1. A microwave receiver 4 for detection is arranged. On the other hand, a display section 5, an alarm lamp 6, an infrared communication device 7, and a remote control receiver 16 are arranged on the rear side of the case body 1 (the side disposed toward the rear of the vehicle (driver side). A GPS receiver 8 is arranged on the top side inside the main body 1. Furthermore, an adapter jack 9 is arranged on one side of the case main body 1, and a power switch 10 and a DC (not shown) are arranged on the other side. The case body 1 also has a built-in speaker 20.

In this embodiment, the display unit 5 is a 2.4-inch small liquid crystal display, and the display surface is on the rear side of the case body 1 (the side disposed toward the rear of the vehicle (driver side)). The height H of the rear side of the case body 1 in which the display section 5 is mounted is larger than the height H0 of other parts.

As shown in FIG. 2, the infrared communication device 7 sends and receives data to and from a communication device including a built-in infrared communication device, such as a mobile phone 12. Adapter jack 9 is a terminal to which memory card reader 13 is connected. By connecting the memory card reader 13 to the adapter jack 9, data stored in the memory card 14 attached to the memory card reader 13 can be imported into the memory card 13, and the contents of the database 19 and the memory of the control unit 18 can be transferred to the memory card 14. You can write to. More specifically, when the data stored in the memory card 14 includes updated information such as alarm target information, which is information regarding a new target or other alarm target, the control unit 18 updates the updated information with the built-in device. The data is stored (downloaded) in the database 19 and the data in the database 19 is updated. Note that the function of the memory card reader 13 may be configured to be built into the main body case 1.

The database 19 is a nonvolatile memory (eg, EEPROM) inside the microcomputer of the control unit 18 or externally attached to the microcomputer. Warning target information, which is information regarding certain warning targets, is registered in the database 19 at the time of shipment, and data regarding warning targets added thereafter can be updated as described above. Furthermore, data updating can also be performed via the infrared communication device 7.

The DC jack is for connecting a cigarette plug cord (not shown), and is connected to a cigarette socket of the vehicle via the cigarette plug cord to receive power supply. The radio receiver 15 receives incoming radio waves of a predetermined frequency. The remote control receiver 16 performs data communication with a remote control (portable device: child device) 17 using infrared rays, and performs various settings for the device. Further, the switch section 3 is also connected to the control section 18 (not shown), so that settings similar to those of the remote control 17 can be made. The remote control 17 includes a playback button, a standby switching button, a setting button, a selection button, a cancel button, a decision button, and up, down, left, and right cross buttons.

The control unit 18 is a microcomputer equipped with a CPU, ROM, RAM, non-volatile memory, I/O, etc., and is connected to each of the above-mentioned parts as shown in FIG. 2, and based on information input from each of the above-mentioned parts. It executes predetermined processing, controls each of the above parts, and outputs predetermined warnings, messages, and information. Note that these basic configurations can be basically the same as conventional ones.

The functions of the radar detector of this embodiment are realized by being stored in the EEPROM of the control unit 18 as a program executed by the computer included in the control unit 18, and executed by the computer included in the control unit 18. Functions realized by the computer by the program included in the control unit 18 include a GPS log function, a standby screen display function, a radar scope display function, a GPS alarm function, a radar wave alarm function, a radio alarm function, and the like.

The GPS log function is a function in which the control unit 18 associates the current position detected by the GPS receiver 8 with the detected time and speed (vehicle speed) every second and stores it in the memory card 14 as a position history. This position history is recorded in, for example, NMEA format.
The standby screen display function is a function that displays the speed, latitude, longitude, and altitude of the own vehicle detected by the GPS receiver 8 on the display unit 5, as shown in FIG. 3(a).

As shown in FIG. 3(b), the radar scope display function detects an alarm target (also referred to as a target) within a predetermined range (for example, within a range of about 1 km) from the current position detected by the GPS receiver 8. ) from the position information stored in the database 19, and displays the relative positional relationship between the own vehicle position and the position of the warning target on the display unit 5. In Figure 3(b), "W" on the left side indicates the west direction, "E" on the right side indicates the east direction, and "N" on the top side indicates the north direction. The icon at the intersection with the vertical line extending downward from ``'' indicates the vehicle's position. Further, icons having letters such as "L", "RD", "P", and "N" indicate the type and position (existence location) of the alarm target.

When a press of the standby switch button provided on the remote control 17 is detected during execution of the standby screen display function as shown in FIG. 3(a), the screen is switched to the radar scope display function as shown in FIG. 3(b).

The control unit 18 operates a GPS alarm function, a radar wave alarm function, or Executes processing to realize each function such as a wireless alarm function.

The radar wave warning function is displayed when the microwave receiver 4 detects a signal corresponding to a microwave in the frequency band emitted from a speed measuring device (such as a mobile radar (hereinafter simply referred to as "radar")). This is an alarm function that displays an alarm screen on the unit 5 and outputs an alarm sound from the speaker 20. For example, when the microwave receiver 4 detects a microwave in the microwave frequency band emitted by a radar, a schematic diagram or photograph of the radar stored in the database 19 is displayed as an alarm screen on the display unit 5, as shown in FIG. At the same time, the voice data stored in the database 19 is read out and a voice saying "Radar. Be careful of speed" is output from the speaker 20. During audio output, the alarm lamp 6 is turned on.

The wireless alarm function is a function that issues an alarm when the wireless receiver 15 receives radio waves emitted by an emergency vehicle or the like so as not to interfere with the vehicle's movement. Radio alarm functions include enforcement radio, car location radio, digital radio, special small radio, police radio, police telephone, police activity radio, towing radio, helicopter radio, fire helicopter radio, fire radio, emergency radio, and highway radio. , scans the frequencies of security radios, etc., and when a radio signal is received at the scanned frequency, a schematic diagram indicating that a radio signal corresponding to the frequency has been received stored in the database 19 for each radio type is displayed as an alarm screen. At the same time, the audio data stored in the database 19 for each wireless type is read out, and the speaker 20 outputs an alarm sound indicating the wireless type. For example, when a police radio signal is received, a voice message such as "This is a police radio signal. Be careful of speed" is output. During audio output, the alarm lamp 6 is turned on.

The GPS alarm function is activated at predetermined time intervals (1 second intervals) by an event from a timer in the control unit 18 while the standby screen display function in FIG. 3(a) or the radar scope display function in FIG. 3(b) is being executed. This process uses the current position detected by the GPS receiver 8 and the warning target information stored in the database 19 to determine whether the warning condition (predetermined approach relationship) is satisfied, and if the warning condition is met, the warning is issued. It is a function that emits.

First, examples of the types of warning targets include drowsy driving accident locations, vehicle speed measurement devices (radar type/H system/loop coil/LH system), mobile vehicle speed measurement areas, speed limit switching points, enforcement areas, Inspection area, parking monitoring area, N system, traffic monitoring system, intersection monitoring point, traffic light prevention system, police station, accident-prone area, vehicle-targeting area, sharp/continuous curves (highway), branching/merging points ( (Expressway), Advance ETC lane guidance (Expressway), Service area (Expressway), Parking area (Expressway), Highway oasis (Expressway), Smart interchange (Expressway), Gas station in PA/SA (Expressway) ), tunnels (expressways), highway radio reception areas (expressways), prefectural border announcements, roadside stations, and viewpoint parking.

The warning target information stored in the database 19 is information regarding each individual warning target, including location information including longitude and latitude for identifying the location of the warning target, and warning target information that is useful for the driver to identify the warning target. There is specific information. In this embodiment, the position information is absolute position information using longitude and latitude. This is preferable because the relative positional relationship with the current position detected by the GPS receiver 8 can be easily determined.

The information for specifying the alarm target includes type information indicating the type of the alarm target, text information indicating the position of the alarm target, audio information indicating the alarm target, image information indicating the alarm target, and the like. If audio information, image information, etc. indicating a warning target corresponds to the type information of the warning target, it is not stored as warning target information for each individual warning target, but is stored separately in a predetermined storage area as common information. You can also do that. When issuing a warning, the control unit 18 can read out the type information stored as warning target information, obtain image information, audio information, etc. corresponding to the type target, and output the warning.

Common image information includes image data such as a schematic diagram that allows the type of alarm target to be easily understood. A schematic diagram is also a mark that allows the type of alarm target to be visually and intuitively understood. For example, there are 3D images of vehicle speed devices, police cars, police officers, etc. By displaying these schematic diagrams on the display unit 5 at the time of notification, the driver can intuitively understand the type and content of the current warning target. Then, as will be described later, by drawing the own vehicle icon at the own vehicle position on the display area of the display unit 5 and drawing the schematic diagram at the position of the warning target location, This is more preferable because it allows you to intuitively understand whether there is a warning target.

In addition, the audio information is outputted from the speaker 20 as audio information, for example, relative positional relationships such as "1km ahead on the left is the expressway H system" or "just ahead is the general road N system", the type of warning target, etc. This is data for In the above example, voice data indicating the relative positional relationship between the vehicle's current position and the warning target, such as "to the left", "1 km ahead", "immediately ahead", etc., and the "general road N system", etc. The audio data for specifying the type and content of the warning target, such as in the "Expressway H System", are managed and stored separately, and the control unit 18 combines and outputs the respective audio data when making a notification.

By separately managing fixed audio information (audio data) etc. according to the type of alarm target, it is no longer necessary to register the same information as alarm target information for each individual alarm target, reducing the consumption of memory space. The amount can be reduced.

For example, while the standby screen display function shown in FIG. 3(a) or the radar scope function shown in FIG. 3(b) is being executed, the database 19 is periodically accessed based on the current position and When the distance from the own vehicle reaches the approach warning distance stored in the database 19 of 2 km, 1 km, or 500 m, data of a schematic diagram or photograph of the loop coil that is the target of the warning is read from the database 19. At the same time, the sound data stored in the database 19 is read out and an alarm sound is output from the speaker 20 to provide an approach notification. For example, when approaching 500m, a radar scope screen similar to that shown in Fig. 3(b) is displayed on the right side of the screen as shown in Fig. 3(c), and the position of the loop coil that is the target of the alarm and the own vehicle position is displayed. In addition to displaying the relationship, data of a schematic diagram or photograph of the loop coil that is the target of the alarm indicating the loop coil is read from the database 19 and displayed on the display unit 5, and voice data saying "Loop coil is 500 meters ahead, be careful of speed" is displayed. It is read from the database 19 and output from the speaker 20. Further, the alarm lamp 6 is turned on while the alarm sound is being output.

Furthermore, the database 19 stores map data including road network information. This road network information is data necessary when searching for recommended routes in car navigation systems, etc., and includes information such as road networks (road layouts) and traffic regulations such as one-way streets. Furthermore, this road network information stores the location information (latitude and longitude) of the nodes at the intersections of roads or inflection points of roads, and also stores the connection relationships of other nodes to which each node connects. The information shown is memorized. In this way, adjacent nodes are connected to each other based on the information indicating the connection relationship of each node, and the connected nodes become a road link. Note that since it does not guide you to a destination like a car navigation device, there is no detailed data such as display data of facilities, houses, etc., and it is simple data.

In this embodiment, the condition for issuing an approach warning is based on whether the distance between the current location and the location of the warning target has reached the approach warning distance, but this distance is not a straight-line distance, but the warning is determined based on road data. This is done using the distance (traveling distance) assuming that the vehicle travels along the route to the target. Specifically, the control unit 18 executes the following processes (1) to (3).

(1) The control unit 18 first extracts warning targets existing within a radius r (for example, 1 km, 2 km) from the own vehicle position (current position) (condition 1). This can be performed using the same algorithm as the conventional process for extracting alarm targets existing around the current position (circle with radius r) based on straight-line distance, and the extracted alarm targets are used as alarm target candidates. Here, r is preferably set to a predetermined approach distance or less in (3) below. Assuming that you drive along the actual road from your current position to the warning target, the travel distance will be equal to or longer than the straight line distance from your current position to the warning target, so by setting r to the approach distance, , it is possible to avoid extracting as alarm target candidates those that cannot be alarm targets for which an alarm should be issued. When the travel distance and the straight-line distance are equal, this means that the current position of the vehicle is connected to the warning target by a single straight road, and in many cases, the straight-line distance is shorter. Become. Therefore, by setting r to be shorter than the predetermined approach distance in (3), it is preferable to reduce the number of candidates to be extracted as warning targets and reduce the load of performing the processes after (2).

(2) Next, the control unit 18 executes a route search from the current position to each warning target candidate. This is determined using the technique of searching for recommended routes in car navigation systems. That is, each warning target candidate is regarded as a destination in the navigation system, the position information of each warning target candidate is sequentially set as the position information of the destination, and the recommended route from the current position to the destination is stored in the database 19. Calculated based on stored road network information. In the database 19, as road network information, location information of nodes such as intersections and information indicating connection relationships between nodes are registered, so the control unit 18 sequentially passes through adjacent nodes from the current location. A route candidate is determined to reach the location of the warning target candidate set as the destination, and one route that meets the conditions is determined as the recommended route. As a condition for such a recommended route, the recommended route is the one with the shortest distance between each route. Alternatively, instead of the shortest distance, a route that takes the shortest time may be determined as the recommended route. Furthermore, when searching for a route, various conditions may be added, such as giving priority to general roads or giving priority to toll roads. As a method for calculating this recommended route, a known method such as Dijkstra's method can be used, for example. Furthermore, the control unit 18 calculates the distance traveled from the current position to the warning target candidate along the determined recommended route. In the present embodiment, the recommended route is determined to be the route with the shortest travel distance up to the warning target candidate, so the travel distance determined at the time of such determination is used.

(3) The control unit 18 sets a warning target to issue a warning if the distance traveled to reach the warning target candidate through the recommended route is within a predetermined approach distance (for example, 2 km) (condition 2) . Furthermore, if the installation direction (monitoring direction) is registered for the warning target, the control unit 18 determines that the travel distance is within a predetermined approach distance and that the travel distance is within the predetermined approach distance and that the warning target candidate is immediately before reaching the warning target candidate by traveling on the recommended route. A warning target whose traveling direction of the vehicle and the installation direction of the warning target satisfy the warning conditions is extracted, and is set as the warning target to which a warning should be issued (condition 3).

For example, if the alarm target is a vehicle speed measuring device, there is a monitoring area for measuring the traveling speed of the vehicle. If the vehicle speed measurement device emits microwaves, this monitoring area is a predetermined angular range to the left and right of the direction in which the antenna that emits the microwaves is facing, and a certain distance from the vehicle speed measurement device. Within the range of Therefore, if the vehicle speed measuring device is approached from the opposite side to the installation direction, there is little need to issue an alarm to notify the presence of the vehicle speed measuring device. Therefore, the orientation of the vehicle speed measurement device (antenna) is registered as the installation direction, and from the relationship with the direction of travel of the vehicle, even if the distance to the warning target candidate is short, it can be determined whether the warning target requires a warning or not. can be judged. In this way, the installation direction of the alarm target can specify the monitoring area, but it is not limited to the range where the microwave is emitted as described above. If there is a warning target to be monitored, etc., it is preferable to set the direction in which either the up or down road extends as the installation direction.

Next, determination based on the above processes (1) to (3) will be explained while showing a specific example. For example, as shown in FIG. 5, it is assumed that there are four objects registered as alarm targets (satisfying condition 1) existing around (within radius r) the current position of own vehicle G. Then, by executing the process (1), the control unit 18 extracts these four alarm targets as alarm target candidates K1 to K4. Next, the control unit 18 executes the process (2) and performs a route search for each of the warning target candidates K1 to K4. That is, the control unit 18 sets the warning target candidate K1 as the destination and searches for a recommended route from the own vehicle position. Then, for example, as shown in FIG. 6A, the control unit 18 determines a route R1 that turns left at the first T-junction and then turns left again at the next crossroads as the recommended route.

Next, the control unit 18 sets the warning target candidate K2 as the destination and searches for a recommended route from the own vehicle position. For example, as shown in FIG. 6(b), after turning left at the first T-junction, , the straight route R2 is determined as the recommended route. Similarly, the control unit 18 sets the warning target candidate K3 as the destination, searches for a recommended route from the own vehicle position, and determines, for example, a route R3 as shown in FIG. 6(c) as the recommended route. Since the warning target candidate K3 is set on an expressway, a vehicle traveling on a general road takes a route that involves driving to an interchange and then entering the expressway. Further, the control unit 18 next sets the warning target candidate K4 as the destination, searches for a recommended route from the own vehicle position, and determines, for example, a route R4 as shown in FIG. 6(d) as the recommended route.

Thereafter, the control unit 18 executes the process (3) and extracts warning target candidates that satisfy Condition 2 or Condition 3. First, in the judgment based on the distance traveled to reach the warning target candidate through the common recommended route under conditions 2 and 3, the warning target candidate K3 on the expressway has a distance traveled in comparison to the straight line distance. is extremely far away and is beyond approach distance, so it is excluded from the actual warning target. In this way, if the road type of the road on which the vehicle is currently traveling and the road on which the warning target is installed is different, the road type can be removed from the warning target in many cases without determining whether the road types match or do not match.

That is, in this type of radar detector, it is possible to switch between expressways, general roads, both, etc. as the target to be actually notified by setting. If "Both" is selected, it may be bothersome to be notified of a warning target for an expressway while driving only on general roads. In this case, only "general roads" may be selected as the notification target, but switching the settings is complicated and there is a risk of erroneous settings. Similarly, while driving on an expressway, the driver may find it bothersome to be notified of a warning target installed on a general road or the like along which the driver is traveling. In this case, only "expressway" may be selected as the notification target, but switching the settings is complicated and there is a risk of erroneous settings. Furthermore, for example, if a warning target is set at a point on a general road that is relatively close to the exit of the expressway, if you set the warning target to be notified only to the expressway, you can get off the expressway and go to the general road. It is only after entering the area that one learns of the existence of the warning target. In other words, there is a problem in that the existence of the warning target cannot be known near the exit on the expressway.

On the other hand, as in this embodiment, if a warning is issued on the condition that the distance traveled along the recommended route to the warning target candidate becomes less than or equal to the approach distance, as shown in FIG. As such, since the traveling distance from the vehicle G traveling on the general road to the warning target candidate K3 on the expressway is long, it is possible to prevent the warning from being issued. Furthermore, if a vehicle exists at the position of the warning target candidate K3 (while driving on an expressway), the warning target candidates K2 and K4 are very close in straight line distance from the vehicle position, but are not actually the warning target. In order to reach the positions of candidates K2 and K4, it is necessary to get off at a distant interchange exit onto a general road, drive on the general road, and return, making the distance traveled very long. Therefore, the warning target candidates K2 and K4 in this case can still be excluded from the targets for which a warning is issued. On the other hand, although specific illustrations are omitted, when a vehicle is driving near an expressway exit, the distance traveled to the nearest warning target installed on the road around the exit is calculated as follows: Since the time is good, it is relatively short and can be set as an alarm target to issue an alarm. Therefore, by making a judgment based on the distance traveled to reach the warning target candidate through the recommended route, normally when driving on a general road or expressway, warning targets on different road types will not be alerted. In addition, it is possible to prevent alarms from occurring while driving on an expressway, and to alert targets on a general road near the expressway exit, or vice versa. A warning target near the entrance can be set as a target for issuing a warning.

Furthermore, in the case of the above example, since the installation directions of the four alarm target candidates K1 to K4 are all registered (the direction of the arrow in the figure is monitored), the control unit 18 determines whether Condition 3 is satisfied. Decide whether or not. When a vehicle is moving toward the installation direction, if it continues as it is, it will enter the monitoring area of the alarm target and be monitored. For example, if the warning target is a vehicle speed measuring device, the traveling speed of the own vehicle is measured, and if the warning target is the N system, the license plate of the own vehicle is photographed.

In other words, as shown in Figure 7(a), if the direction in which the vehicle is traveling and the direction in which the alarm target is installed (monitoring direction) are opposite to each other (the angle formed is 180 degrees), the warning will be It can be determined that there is a warning target that should be alerted, and that if the vehicle continues as it is, it will enter the monitoring area of the warning target. On the other hand, as shown in FIG. 7(b), if the angle between the vehicle's traveling direction and the installation direction of the monitoring target (monitoring direction) is 0 degrees, it is possible to determine whether the vehicle is traveling in the opposite direction to the alarm target. Even if the vehicle is moving toward a warning target, the monitoring direction is different, so it is assumed that the vehicle is not a warning target for which a warning should be issued. Further, in the present embodiment, in the example shown in FIG. 7, if the angle is within a ±predetermined angle range (for example, ±90 degrees) around 180 degrees, it is determined that the alarm target should be issued. Of course, the angle range is not limited to 90 degrees and can be set arbitrarily. A specific algorithm for determining whether or not there is a predetermined angular relationship between the installation direction of the alarm target and the vehicle's traveling direction can be realized using, for example, the technology disclosed in Japanese Patent Application Laid-Open No. 2002-228741. can.

What is important in this embodiment is what happens to the relationship between the traveling direction of the vehicle and the monitoring direction of the warning target when the vehicle is finally driving on the road where the warning target is installed. It's Iruka. In other words, for example, if we focus on the warning target candidate K4, the current traveling direction of the vehicle and the installation direction of the warning target candidate K4 are facing almost the same direction, so the warning will be issued based on the traveling direction of the vehicle at the current position. However, when actually reaching the warning target candidate K4 and passing in front of it, the direction of installation of the warning target is determined as shown by route R4 in FIG. 6(d). This means that the vehicle will be traveling towards the target area, and will be subject to a warning that should be issued.

Also, if we focus on the warning target candidate K1, the current traveling direction of the vehicle and the installation direction of the warning target candidate K1 are facing almost opposite directions, so based on the traveling direction of the vehicle at the current position, a warning should be issued. However, when actually reaching the warning target candidate K1 and passing in front of it, it is necessary to follow the installation direction of the warning target as shown by route R1 in FIG. 6(a). The vehicle will be traveling in the same direction, and will no longer be the subject of a warning that should be issued.

As a result, in the relationship between the traveling direction of the vehicle and the installation direction of the warning targets, the warning target candidates K2 and K4 are the targets for issuing a warning, and the warning target candidates K1 and K3 are not the targets for issuing a warning. Therefore, the control unit 18 extracts the warning target candidates K2 and K4 as warning targets that satisfy condition 3.

Of course, even with the conventional method disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-228741, if the vehicle approaches the warning target candidate K4, it is possible to issue a warning because the traveling direction of the vehicle and the installation direction of the warning target are opposite to each other. However, in this embodiment, the alarm can be issued from a location further away than that. In addition, in the above conventional method, the warning target candidate K1 is once recognized as the target for which a warning should be issued and a warning is issued, and as the vehicle advances, it deviates from the predetermined angle range in front of the vehicle position as a reference. However, in this embodiment, no warning is issued from the beginning, so it is possible to prevent unnecessary warnings and notifications from being issued to the driver.

Further, the control unit 18 notifies the alert target candidates K2 and K4, which are extracted in this way and are the targets to which an alert should be issued, using the alarm output means such as the display unit 5, the lamp 6, the speaker 20, etc. The notification in this case can be basically the same as that conventionally known.

That is, FIG. 8 occupies an example of an alarm screen based on the example shown in FIG. Here, the two warning target candidates K2 and K4 are used as actual warning targets, and predetermined polygons are drawn at the corresponding positions on the map according to the warning types registered for them.

First, the layout of the screen area is such that a strip-shaped icon display area E2 is placed above a rectangular main display area E1 that occupies most of the screen area. Of course, this icon display area E2 may be provided at an appropriate position below or on the left or right, or may not be provided. The icon display area E2 includes icons that indicate the operational status of the device, such as an icon I1 that indicates that GPS is being received, and an icon I2 that indicates the type of alarm target. Such display is performed under control from the control unit 18. Furthermore, the remaining distance to the warning target is drawn on the right end of the icon display area E2. This remaining distance may be drawn in a separate window at an appropriate position, such as the lower right of the main display area E1, in order to make it more noticeable. In that case, the current time, date, or other information may be drawn on the right end of the icon display area E2. Further, the remaining distance may be a straight line distance as in the conventional case, but preferably it is a traveling distance from the current position to the target of the warning along the recommended route. By doing this, the decreasing (approximating) value of the remaining distance matches the actual distance traveled, so there is no sense of discomfort.

The main display area E1 mainly indicates the positional relationship between the warning target and the own vehicle, and is an area for displaying objects each having a predetermined shape at each position. This display unit 5 divides into a plurality of layers and draws respective images and the like. Specifically, the background color is drawn on the lowest layer. This background color may be drawn with a gradation so that it becomes brighter toward the front (the side of the vehicle: the lower side of the screen), or may be drawn with a single color. Furthermore, the color varies depending on the positional relationship with the alarm target. In other words, if the alarm target exists but is more than a certain distance away (for example, 500 m or more), the base color is green, and when the distance to the alarm target approaches less than a certain distance, the base color is changed to a different color ( For example, change it to "yellow"). Furthermore, when the vehicle is approaching, the driver can easily understand that the vehicle is approaching by changing the color appropriately, such as using red as the base color.

The remaining distance to the warning target, which is the basis for changing this color, may be based on the straight-line distance between the two as in the past, but preferably it is the distance traveled from the current position to the warning target if the recommended route is taken. That is to say. By changing the color based on the distance traveled, even if the distance is very close in a straight line, such as on an adjacent road, the distance traveled to reach the warning target candidate through the recommended route is calculated. When the vehicle is far away, using green as the base color allows the driver to understand that the vehicle will not arrive immediately.

The control unit 18 calls map data corresponding to the displayed space, and draws the map data (outline road map) on a layer existing above the background color layer. Then, the control unit 18 draws various objects in a layer above the drawing layer of the map data. An object Gob indicating the own vehicle position (hereinafter referred to as "own vehicle object") is drawn at a predetermined position below the main display area R1. In the figure, the vehicle object Gob is drawn as a two-dimensional mark with an arrow indicating the direction of travel drawn inside a circle, but it is better to make the own vehicle object Gob more three-dimensional by constructing it from triangular or quadrangular pyramid polygons. In this case, when the control unit 18 draws the own vehicle object Gob, the apex of the triangular or square pyramid faces forward in the direction of travel of the vehicle, and the vehicle object Gob is drawn so that it appears to be floating in the air. It is best to draw the area (draw the shadow downward). In the following description, even if there is no particular disclaimer, the control unit 18 draws each object and other images on the display screen of the display unit 5.

Furthermore, if there is a warning target to be warned in the displayed space, the object to be warned is drawn at a corresponding position on the screen. At this time, there are often multiple warning targets registered in the database 19 in the vicinity. In this case, one that satisfies the conditions is set as the actual alarm target (warning target), and the alarm target object Kob is drawn at a position on the display screen corresponding to the existing position of the alarm target. For other potential alarm targets, the control unit 18 draws an object corresponding to the type of the detected alarm target at the corresponding position as a POI (Point Of Interest) object Iob.

In the figure, both the warning target object Kob and the POI object Iob are two-dimensional marks with a symbol indicating the type of warning target in a circle, and the warning target object Kob has a symbol that indicates the existence of the warning target at a glance. This is indicated by a pair of triangular indicator marks. Furthermore, if an installation direction is registered for this warning target object Kob, that direction is also indicated by an arrow. As a result, the driver can see at a glance whether or not there is a warning target on the road the driver is planning to drive.

Further, the warning target object Kob and the POI object Iob may also be drawn using three-dimensional polygons, similar to the host vehicle object. In this case, it is preferable that the warning target object Kob is displayed in a three-dimensional shape imitating something related to the actual warning target, since the type thereof can be more intuitively understood.

Further, as a display mode of the warning, in order to draw more attention to the existence of the warning target object Kob, it is preferable to draw a "guide line" connecting the own vehicle object Gob to the warning target object Kob. This guide line has both ends touching or close to the own vehicle object Gob and the warning target object Kob, and is further drawn on or along the road along the route from the own vehicle object Gob to the warning target object Kob. be done.

In particular, when there are a large number of POI objects Iob, it may be difficult to find the object to be alerted at a glance from among them. As shown in Figure 8, it may be difficult to differentiate the POI object from other POI objects Iob by simply adding a triangular indicator mark or making it blink.Especially in the case of a radar detector, car navigation Since the area of the display section is smaller than that of the device, the difficulty in understanding becomes even more pronounced. Therefore, it is better to connect the two using dotted lines or guide lines of different colors. Then, the driver can easily find the object to be warned by following the guide line.

In that case, for example, as shown in FIGS. 9(a) to 9(c), a dotted guide line S may be animated to flow from the host vehicle object Gob to the warning target object Kob, and the end of the guide line S may be If the warning target object Kob is reached, the driver can easily understand the existence of the warning target object Kob by viewing the animation. In addition, the animated guide line S extends along the road, so it is easy for the driver to understand whether or not it is the road he or she is about to proceed on, and whether it is a warning target to be careful of or something unrelated. It can be understood intuitively.
[Other methods for determining recommended route]

In the above-described embodiment, in the process (2), when determining the recommended route that is the standard for determining the travel distance, the control unit 18 selects the shortest distance, etc. from among the plurality of routes from the current position to the warning target candidate. The route that satisfies the following conditions is determined as the recommended route. When determining this recommended route, the installation direction used in condition 3 may be taken into consideration. In other words, the general recommended route is to select the one with the shortest travel distance or the one that will reach the destination in the shortest time from among the many routes from the current point to the destination. As a condition for selecting , on a road where there is a warning target candidate for which an installation direction is set, the recommended route is a route that advances toward the installation direction as the direction to approach the warning target.

Since the installation direction has already been taken into account when determining the recommended route, the determination as to whether or not the alarm should be issued in process (3) above is made based on whether Condition 2 is satisfied or not. I'll do it by hand. In other words, the control unit 18 selects as warning targets to which a warning should be issued if the distance traveled along the recommended route to the warning target candidate is within a predetermined approach distance (for example, 2 km).

To give an example, the recommended route for the warning target candidate K1 is not the route leading from the right side as shown in FIG. 6(a), but the route leading from the left side. In other words, in Figure 6(a), the travel distance is calculated assuming that the route to the warning target candidate is reached from the opposite side of the current direction of travel (clockwise), and if the distance is 2 km or more, the warning is issued. Not targeted.

[Determine whether or not to issue a warning based on the number of left and right turns]
In the above-described embodiments and modified examples, the algorithm for determining whether or not a warning should be issued using road network information is based on the distance traveled when traveling on the recommended route. There is no limitation, and various methods can be used. To give an example, there is one that implements the following (1), (2), and (3)'.

(1) The control unit 18 first extracts warning targets existing within a radius r (for example, 1 km, 2 km) from the own vehicle position (current position) (condition 1). This can be performed using the same algorithm as the conventional process for extracting alarm targets existing around the current position based on straight-line distance, and the extracted alarm targets are used as alarm target candidates.

(2) Next, the control unit 18 executes a route search from the current position to each warning target candidate. In this case, the position information of each warning target candidate is sequentially set as the position information of the destination, and a recommended route from the current position to the destination is determined based on the road network information stored in the database 19. As a method for calculating this recommended route, a known method such as Dijkstra's method can be used, for example.

The detailed explanation of the processes (1) and (2) will be omitted, but they are the same as those described above. Further, when determining the recommended route in this process (2), the installation direction of condition 3 may be taken into account as in the above-described modification.

(3)'Next, find the number of intersections at which you will turn left or right if you proceed along the recommended route from your current location to the warning target candidate. Warning target candidates for which the number of intersections is n or more (the number of intersections that the vehicle passes by going straight is not counted) are not considered as warning targets for which a warning should be issued. In other words, warning target candidates whose number of intersections is less than n are set as warning targets for issuing a warning. In other words, in a case where the vehicle travels on a complicated route that requires turning left or right at intersections n or more times to reach the warning target, there is a high possibility that the vehicle will not travel on the road where the warning target is actually installed. In particular, in cases where the user must turn at intersections multiple times to get there even if the distance in a straight line is short, there is a very high possibility that the user will not go to the location where the warning target is installed. Therefore, if such a warning target is notified, there is a high possibility that the warning will be unnecessary for the driver, so it was decided not to issue a warning target.

Thereby, it is possible to extract an alarm target that is relatively easy to reach (has a high possibility of reaching) from among the alarm targets existing within a certain distance in a straight line, and to issue an alarm. In other words, by not giving a warning to warning targets that are unlikely to actually arrive among the warning targets that exist in the surroundings, the number of warning targets to be alerted can be effectively reduced, making it possible to reduce the number of warning targets necessary for the driver. Appropriate notifications can be made. Of course, even if the number of times is less than n, if the installation direction of the warning target is set, there is a function to discriminate whether or not to issue a warning based on the angular relationship with the driving direction of the immediately preceding road. It's okay.

Further, it is preferable to set n to 2 because it is possible to prevent warning targets installed on other roads parallel to or close to the road the vehicle is traveling on from being used as warning targets for issuing a warning. That is, for example, as shown in FIG. 10(a), assume that while the vehicle G is traveling on the left road, the warning target K is installed on the right road parallel to the vehicle G. In this case, if the driver continues straight on the road on the left, he will not reach the warning target K on the right road. These alarms are useless, and they actually feel like a nuisance.

As is clear from FIG. 10(a), in order for vehicle G to travel along the recommended route and reach warning target K, it is necessary to turn twice, turning right at intersection A and then turning left at intersection B. . Without being limited to this example, when there are two roads that are approximately parallel (do not intersect), a vehicle traveling on one road must at least deviate from the road it is traveling on in order to reach the other road. It is necessary to change the direction of travel (turn right/left) at the intersection on the road you are driving on, and then turn right or left at the intersection on the other road in order to enter the other road, so you must drive at the intersection at least twice. will change course. On the other hand, if a warning target exists on a road that intersects with the road on which the driver is traveling, such as the warning target candidate K2 exemplified in the above-described embodiment, the user only needs to turn once at the intersection on the road on which the vehicle is traveling. , which may result in a situation where you come face-to-face with the target of the warning.

Therefore, by setting n = 2, it is possible to know the warning targets installed ahead of the turn at an intersection before turning, and the warning targets installed on other parallel roads do not need to be notified. .

In the case shown in FIG. 10(a), if a right turn is made at intersection A as shown in FIG. 10(b), the recommended route from the current position of vehicle G to warning target K is intersection B. If you turn left once at , you will reach the warning target K, so a warning will be issued at that point.

Also, as shown in FIG. 10(a), when driving on the left road, there is a warning target on the left road, and the distance traveled to the warning target is the warning target installed on the right side. Even if the travel distance is longer than the distance traveled to K, it is necessary to turn twice to reach the warning target K, so the control unit 18 issues a warning for the warning target installed on the left road.

As for how to issue a warning on the display, if there are multiple warning targets in the surrounding area, it is best to sort them in descending order of the number of times they have turned, and rank them so that the fewer times they have turned, the higher the priority is. Note that if the number of times is the same, the priority is set higher as the distance traveled to the warning target is shorter. Of course, the priority may be further determined by taking into account the priority depending on the type of the warning target.

[Judgment based on time]
As another algorithm for determining whether or not a warning target should be issued, a predicted time until reaching the warning target may be used. That is, the control unit 18 obtains a recommended route using the methods shown in each of the embodiments and modifications described above. Then, the control unit 18 determines the predicted time until the vehicle reaches the warning target when traveling along the determined recommended route, and determines the warning target to be issued if the predicted time is less than a preset reference value. The predicted time may be calculated using, for example, probe information on traffic congestion obtained through VICS or communication.

[Alarm mode for display unit]
As shown in FIG. 11, it is preferable to draw warning information for each surrounding warning target that satisfies Condition 2 or Condition 3 on the virtual signboard 51, overlapping it in the front and back direction to give depth. . Although the warning information described on the virtual signboard 51 includes the type of warning target, information specifying the installation location, and remaining distance, this does not preclude other information from being displayed. Then, for example, when driving on a straight road, the virtual signboard 51 is drawn smaller toward the back so that it has more depth, simulating the view of intersection guide boards installed at multiple intersections from the front side to the back side. . This allows you to see at a glance the high and low priorities. Furthermore, as the route changes as the vehicle travels, the priority order of each warning target also changes, so in such a case, it is preferable to rearrange the virtual signboards 51 according to the priority order.

Further, in the above-described embodiments and modified examples, items that do not satisfy the conditions are not drawn on the display unit 5 as alarm targets that should not be issued, but the present invention is not limited to this, and the display mode It is also possible to change the . That is, objects that do not satisfy the conditions are at least prevented from becoming warning target objects Kob (objects that notify detailed warning information). Furthermore, it is preferable that the content is also included in the POI (Point Of Interest) object Iob. For alarm targets that satisfy condition 1 and become alarm target candidates but do not satisfy conditions 2 and 3, a simple object (such as a simple circle or a circle with a smaller radius) is placed in the corresponding position. etc.). This allows the driver to know that there are some warnings to be issued, although they do not correspond to the warning targets for which a warning should be issued.

In the embodiments and modifications described above, an example was shown in which the electronic device is applied to a radar detector, but the present invention is not limited to this, and may be incorporated as a function of a car navigation device or other electronic device.

Further, in the above-described embodiments and modified examples, the apparatus is provided with a database 19 storing various information, and the control unit 18 accesses the database 19 to read necessary information and perform various processes. The invention is not limited to this. That is, part or all of the information to be registered in the database 19 is registered in the server. The radar detector and other electronic equipment/devices may have a function of communicating with such a server, and the control unit 18 may be a system that accesses the server as appropriate, acquires necessary information, and executes processing.

1 Case body 2 Solar panel 4 Microwave receiver 5 Display section 6 Lamp 7 Infrared communication device 8 GPS receiver 9 Adapter jack 10 Power switch 11 Mobile phone 12 Memory card reader 14 Memory card 15 Wireless receiver 16 Remote control receiver 17 Remote control 18 Control unit 19 Database 20 Speaker

Claims (3)

A function to obtain the current position of the vehicle,
a function of issuing an alarm when the vehicle has a predetermined proximity relationship with an object to be alarmed;
As a condition for searching for a recommended route, a function that prioritizes general roads or toll roads to find a recommended route from the current location to the destination;
has
The function of issuing the alarm is as follows :
The warning target is a device that measures the running speed of a vehicle or a device that monitors a vehicle, and the warning is to be issued based on the traveling direction of the vehicle and the installation direction or monitoring direction of the warning target. It extracts the target object,
The distance traveled by the recommended route from the current position of the vehicle determined by the desired function to the warning target object is within a predetermined approach distance, and the vehicle travels along the recommended route to reach the warning target object. A system for extracting a warning target object that satisfies an alarm condition in which the direction of travel of the vehicle immediately before reaching the target object and the installation direction or monitoring direction of the warning target object. A function to obtain the current position of the vehicle,
a function of issuing an alarm when the vehicle has a predetermined proximity relationship with an object to be alarmed;
a function that identifies the type of road on which the vehicle is traveling and determines a recommended route from the current location to the destination;
has
The function of issuing the alarm is as follows :
The warning target is a device that measures the running speed of a vehicle or a device that monitors a vehicle, and the warning is to be issued based on the traveling direction of the vehicle and the installation direction or monitoring direction of the warning target. It extracts the target object,
The travel distance from the vehicle's current position determined by the function to the target object when traveling on a recommended route passing through roads of the road type is within a predetermined approach distance, and A system for extracting a warning target object in which a traveling direction of a vehicle immediately before reaching the warning target object and an installation direction or a monitoring direction of the warning target object satisfy an alarm condition. A program for causing a computer to implement the functions of the system according to claim 1 or 2 .

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