JP2005030946A - Junction road estimating device, navigation system, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for estimating advance of a vehicle into a junction road to the utmost, even when information about the junction road for joining roads coming close to each other from mutually different heights and running parallel is not included in road map information. <P>SOLUTION: Slope information is acquired in every prescribed time (S170), when a vehicle travels on the parallel roads (S110:YES), a nonflat portion out of the parallel roads is estimated as the junction road for joining the fellow parallel roads, based on the acquired slope information, when a vehicle travel link is changed (S130:YES) or in the like, and the slope information in a position therein is stored in an external memory together with positional information (S190). In the case where the vehicle travels again in the point, the vehicle is estimated to travel on the junction road (S230) when the present slope information is conformed with the slope information stored in the last travel (S220:YES). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for estimating that a vehicle has entered a connected road even when the information about a connected road that connects parallel roads that are approaching and parallel at different altitudes is not included in the road map information. .

  There are known navigation devices that display the current location of the vehicle as it travels along with the road map on the display, set an appropriate route from the current location to the destination, and provide route guidance. It contributes to the drive.

  In such display of the current position of the vehicle and route guidance, it is fundamental to detect the current position of the vehicle. In the current position detection for the vehicle, for example, dead reckoning calculation is performed using the azimuth change amount calculated based on the output value from the gyroscope and the moving distance calculated based on the output value from the vehicle speed sensor. What you do is known as basic technology. However, since this method is “self-contained navigation” in which the vehicle position is detected by the vehicle itself, there is a drawback that the absolute position cannot be detected. For this reason, for example, there is a technique for obtaining a more appropriate current position by obtaining an absolute position (or an absolute direction) by using radio navigation radio waves transmitted from a GPS satellite or a roadside beacon. However, in the case of information from a GPS satellite, it is necessary to assume that an error of about 100 m occurs, so there is a technique for performing correction by so-called map matching processing in order to improve the accuracy of position detection. This is based on the above-mentioned dead reckoning navigation (only self-contained navigation or radio navigation added to self-contained navigation). The position is estimated based on the correlation.

In addition, when performing the correction by the map matching process as described above, the three-dimensional information such as the gradient information and the altitude information is used to estimate the travel road on which the vehicle travels and specify the current position of the vehicle with higher accuracy. (For example, refer to Patent Document 1).
JP-A-11-304510 (5th page, FIG. 2)

  However, the correction by the map matching process as described above is based on the premise that the road shape obtained from the road map information matches the actual road shape. Therefore, for example, when the road map information does not include information on connection roads that connect parallel roads that run parallel and approach at different altitudes, such as general roads and elevated roads that run parallel above, When the vehicle moves from one of the roads to the other via the connection road, it does not detect that the vehicle has entered the connection road. Then, in the parallel running part of the parallel road, because the distance between both roads is often within the error range such as GPS, even though the vehicle moved from one side of the parallel road to the other, Until the distance between the two roads increases, there is a risk that the vehicle may misrecognize that the vehicle is traveling on one side of the parallel road.

  In addition, in order to solve such a problem, while maintaining the above road map information to include information on all connected roads, it is possible to keep the road map information already mounted on the vehicle up to date, This takes enormous effort and cost.

  The present invention has been made in view of such problems, and the object of the present invention is that road map information includes information on connecting roads that connect parallel roads that are approaching and paralleling at different altitudes. Even in the case where there is not, it is intended to provide a technique for estimating as much as possible that the vehicle has entered the connecting road.

  The connected road estimation device according to claim 1, which has been made in order to solve the above-described problem, is that many parallel running roads approaching and paralleling at different altitudes are flat and the connecting roads connecting the parallel running roads are inclined. When the vehicle travels on one side of the parallel road, for example, when the slope degree such as gradient information or altitude information is equal to the slope degree during the previous travel, the vehicle It is estimated that the vehicle is traveling on the connecting road.

  Specifically, the road estimation means (8: In this column, in order to facilitate understanding of the invention, the reference numerals used in the embodiments are attached as necessary. Is not based on the “current position of the vehicle” detected by the current position detection means (1) and the “road map information” stored in the road map information storage means (6). Estimate the road on which the vehicle travels. Further, the inclination degree acquisition means (5, 14) acquires the inclination degree at the point where the vehicle is currently located when the vehicle travels on one of the parallel roads that approach and run parallel at different altitudes. In addition, as a specific example of “parallel running roads that approach and run parallel at different altitudes”, there are a general road and an elevated road that runs parallel to the upper side. In addition, for the above-described “inclination degree”, the inclination degree acquisition unit acquires at least one of “gradient value” or “altitude value” of the point where the vehicle is currently located, and the acquired “gradient value” or “altitude value”. It is conceivable to calculate “degree of inclination” based on at least one of “value”. Here, the “gradient value” is calculated based on an output signal from the G sensor or the like, for example, and may be a slope value at that point such as 3 degrees, or an average value per predetermined moving distance may be used. Good. On the other hand, the “altitude value” is calculated based on an output signal from a GPS receiver, for example, and may use an altitude value at that point, for example, an altitude of 5 m, or a change amount or an average value per predetermined moving distance May be used. The “movement distance” may be a linear distance or an actual travel distance.

  Here, when it is estimated that the vehicle is traveling on one of the parallel roads by the traveling road estimation unit, the current position of the vehicle is determined to be not flat based on the inclination degree acquired by the inclination degree acquisition unit. When this is done, the storage control means (8) causes the inclination degree storage means to store the inclination degree together with position information indicating the current position of the vehicle. Specific examples of “determining that the current position of the vehicle is not flat” include (i) when the slope degree includes a slope value, when the slope value is not near zero, or (b) the slope degree is For example, when the altitude value is included, the change amount of the altitude value at a predetermined moving distance is not near zero. Further, when it is estimated that the vehicle is traveling on one of the parallel roads, when the inclination degree storage means stores the inclination degree at the current position of the vehicle, the traveling road estimation means reads the inclination degree. When the read degree of inclination and the degree of inclination acquired by the degree-of-inclination acquisition unit are substantially equal, the vehicle is connected to the connecting road that connects one of the parallel roads and the other of the parallel roads. Presume that you are driving. It should be noted that the determination criterion “substantially equal” may be defined in advance. For example, when the slope degree includes a slope value, for example, when the slope value of the current slope degree and the slope value of the read slope degree are within ± 0.2 degrees, for example, “substantially equal”. And so on.

  As described above, according to this connection road estimation device, when a vehicle travels on one side of a parallel road, for example, when the degree of slope such as gradient information or altitude information is substantially equal to the degree of slope in the previous travel, the vehicle Since it is estimated that the vehicle is traveling on a connected road, even if the road map information does not include information on the connected road that connects parallel roads that are approaching and running at different altitudes, It is possible to estimate that it has entered as much as possible.

  In addition, this makes it possible to easily maintain information on connected roads that are not included in the road map information, so that the convenience of the user can be improved without waiting for the upgrade date of the road map information by a map producer or the like. Can do.

  In this case, the inclination degree acquisition unit may acquire the inclination degree every predetermined time such as 1 second, and store the acquired inclination degree in the inclination degree storage unit. Further, the inclination degree acquisition means may acquire the inclination degree at predetermined intervals such as 10 m, and store the acquired inclination degree in the inclination degree storage means.

  In the connection road estimation device according to claim 1 described above, it is the inclination degree storage means that determines whether or not the current position of the vehicle is flat based on the inclination degree acquired by the inclination degree acquisition means. However, the present invention is not limited to this. For example, it is determined whether or not the inclination degree read from the inclination degree storage means is substantially equal to the inclination degree acquired by the inclination degree acquisition means. When the traveling road estimation means determines, it may be determined whether or not the current position of the vehicle is flat based on the inclination degree acquired by the inclination degree acquisition means. Specifically, as in claim 2, the traveling road estimation means is based on the “current position of the vehicle” detected by the current position detection means and the “road map information” stored in the road map information storage means. Estimate the road on which the vehicle travels. In addition, the inclination degree acquisition means acquires the inclination degree at the point where the vehicle is currently located when the vehicle travels on one of the parallel roads that approach and run parallel at different altitudes. Here, when it is estimated by the traveling road estimation means that the vehicle is traveling on one of the parallel roads, the storage control means uses the inclination degree acquired by the inclination degree acquisition means as the current position of the vehicle. It is memorize | stored in the inclination degree memory | storage means with the positional information shown. Further, when it is estimated that the vehicle is traveling on one of the parallel roads, when the inclination degree storage means stores the inclination degree at the current position of the vehicle, the traveling road estimation means reads the inclination degree. Then, when it is determined that the read inclination degree and the inclination degree acquired by the inclination degree acquisition means are substantially equal and the current position of the vehicle is not flat based on the inclination degree, the traveling road estimation means It is estimated that the vehicle is traveling on a connecting road connecting one of the traveling roads and the other of the parallel traveling roads.

  As described above, according to this connection road estimation device, when a vehicle travels on one side of a parallel road, for example, the slope degree such as slope information or altitude information is substantially equal to the slope degree in the previous travel and the slope degree. When it is determined that the current position of the vehicle is not flat based on this, it is assumed that the vehicle is traveling on the connecting road, so the connecting road that connects the parallel roads that are approaching and paralleling at different altitudes Even when the information on the road map information is not included, it is possible to estimate as much as possible that the vehicle has entered the connecting road.

  Now, some parallel roads that run close to each other at different altitudes have portions that are not flat. Then, when the vehicle travels on such a parallel road, in order to estimate that the portion that is not flat is a connection road of the parallel road based on the inclination as described above, the parallel travel other than the connection road There is a risk that an uneven road portion of the road is erroneously determined as a connection road. Therefore, it is conceivable to eliminate the degree of inclination of the road portion when the parallel road has a non-flat road portion. Specifically, when it is estimated that the vehicle is not traveling on the parallel road after it is estimated that the vehicle is traveling on one of the parallel roads by the traveling road estimation means, the storage control means is It is conceivable to delete the inclination degree at a point outside the predetermined range from the current position of the vehicle among the inclination degrees stored by the inclination degree storage means (claim 4).

  For example, the degree of inclination at a point belonging to a circular area with a predetermined radius centered on the current position of the vehicle is stored as it is, while the outside of the circular area with a predetermined radius centered on the current position of the vehicle. For example, the degree of inclination at a point belonging to is deleted. Also, the degree of inclination at a point belonging to the range of the predetermined travel distance along the vehicle travel locus is stored as it is, while the degree of inclination at a point outside the range of the predetermined travel distance along the vehicle travel locus is stored. Is erased.

  In this way, the degree of inclination at a position other than the connected road can be eliminated as much as possible, so the possibility of erroneously estimating a road portion that is not flat on the parallel road other than the connected road as a connected road is reduced. be able to.

  By the way, the above-described traveling road estimation device can be realized as a part of the navigation device (100). Specifically, as shown in claim 5, the connected road estimation device according to any one of claims 1 to 4 and notification control means (8) are provided, and the notification control means is connected road estimation. “Road map information” including “current position of vehicle” detected by current position detection means in the apparatus and “connected road” estimated that the vehicle is traveling by the traveling road estimation means in the connected road estimation device Can be notified to the notification means (10). This also improves the effectiveness of the navigation device.

  In addition, as shown in Claim 6, the traveling road estimation means and the storage control means in the connected road estimation apparatus according to any one of Claims 1 to 4 can be realized as a program that causes a computer to function. Therefore, the present invention can be realized as a program invention. In the case of such a program, for example, the program is recorded on a computer-readable recording medium such as an FD, MO, DVD-ROM, CD-ROM, or hard disk, and is used by being loaded into a computer and started up as necessary. be able to. In addition, the ROM or backup RAM may be recorded as a computer-readable recording medium, and the ROM or backup RAM may be incorporated into the computer for use.

  Embodiments to which the present invention is applied will be described below with reference to the drawings. Needless to say, the embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.

FIG. 1 is a configuration diagram illustrating a configuration of an in-vehicle navigation device according to an embodiment.
[Description of configuration of in-vehicle navigation device 100]
As shown in FIG. 1, the in-vehicle navigation device 100 of this embodiment is connected to a position detector 1, a map data input device 6, an operation switch group 7, a control circuit 8 connected thereto, and a control circuit 8. An external memory 9, a display device 10, an external information input / output device 11 and a remote control sensor 12 are provided.

[Description of configuration of position detector 1]
Among these, the position detector 1 is a well-known geomagnetic sensor 2, gyroscope 3, distance sensor (vehicle speed sensor) 4, and GPS receiver 5 for GPS that detects the position of the vehicle based on radio waves from a satellite. have. Since these sensors 2, 3, 4, 5 have errors of different properties, they are configured to be used while being interpolated by a plurality of sensors. Depending on the accuracy, a part of the above may be used, and further, a steering rotation sensor, a wheel sensor of each rolling wheel, or the like may be used. The position detector 1 corresponds to a current position detecting unit.

[Description of the configuration of the map data input device 6]
The map data input device 6 is a device for inputting various data including so-called map matching data and map data for improving the accuracy of position specification. As a recording medium for these data, a CD-ROM or DVD is generally used because of the amount of data, but another medium such as a magnetic storage device such as a hard disk or a memory card may be used.

  The road map data (road map information) in the map data is a map constructed by connecting a plurality of nodes such as intersections with links, and a unique number (link) for each link is specified. ID), “road type (link class)” for identifying an expressway, a toll road, a general road, an attachment road, etc., “start coordinates” and “end coordinates” of the link, and a link indicating the length of the link Long and link information consisting of data of a road ID for identifying a road (for example, information for identifying a road such as a national highway No. ○ line) is provided. The map data input device 6 corresponds to road map information storage means.

[Description of configuration of external memory 9]
The external memory 9 is composed of a non-volatile memory, and is used for storing information necessary for executing various processes. The external memory 9 includes a temporary storage area and a normal storage area. Of these, the temporary storage area is used to temporarily store gradient information and position information according to an instruction from the control circuit 8. On the other hand, the normal storage area is used for moving the gradient information and the position information temporarily stored in the temporary storage area in accordance with an instruction from the control circuit 8 and moving them from the temporary storage area. The external memory 9 corresponds to the inclination degree storage means.

[Description of Configuration of Display Device 10]
The display device 10 is a color display device. As illustrated in FIG. 3A, the screen of the display device 10 includes a mark indicating the current position of the vehicle input from the position detector 1 and a map data input device 6. More input map data and additional data such as a guide route to be displayed on the map can be displayed in an overlapping manner. The display device 10 corresponds to notification means.

[Description of Configuration of External Information Input / Output Device 11]
The external information input / output device 11 receives an FM broadcast signal via a radio antenna (not shown) or receives a radio wave beacon signal and an optical beacon signal from a fixed station for VICS service arranged near the road. The received information is sent to the control device 8 for processing. Further, it is connected to a mobile phone (not shown) and has a function of acquiring information from an information center or connecting to the Internet and acquiring information from a server on the Internet.

[Description of the configuration of the remote control terminal 13, operation switch group 7, etc.]
Further, when the in-vehicle navigation device 100 inputs the position of the destination from the remote control sensor 12 or the operation switch group 7 via the remote control terminal (hereinafter referred to as a remote controller) 13, the in-vehicle navigation apparatus 100 is optimal from the current position to the destination. A so-called route guidance function for automatically selecting a route to form and display a guidance route is also provided. A technique such as the Dijkstra method is known as a technique for automatically setting an optimum route. For example, a touch switch or a mechanical switch integrated with the display device 10 is used for the operation switch group 7 and is used for various inputs.

[Description of Configuration of Control Circuit 8]
The control circuit 8 is configured around a well-known microcomputer including a CPU, ROM, RAM, I / O and a bus line connecting these configurations, and based on a program stored in the ROM and RAM, A map that calculates the current position of the vehicle as a set of coordinates and traveling directions based on each detection signal from the position detector 1 and displays a map or the like near the current position read via the map data input device 6 on the display device 10. Based on the display processing, the point data stored in the map data input device 6 and various data stored in the external memory 9, the destination facility is selected according to the operation of the operation switch group 7, the remote controller 13, etc., and the current position A route calculation process for automatically obtaining the optimum route (destination route) from the destination to the destination is performed. A technique such as the Dijkstra method is known as a technique for automatically setting an optimum route in this way.

  Further, the control circuit 8 performs a route guidance process for performing route guidance based on the guidance route obtained by the route calculation process. This route guidance is based on the result of route calculation and road shape data stored in the map data, intersection location information, crossing location information, etc. Calculate whether you need to turn right or turn left (ie, so-called navigation), and based on the calculation results, for example, a map of the current location, a highway schematic, or near the intersection near the intersection Are drawn and displayed on the display device 10. Further, audio output from an audio output device (not shown) is also used.

  Further, an acceleration sensor (G sensor) 14 that detects acceleration / deceleration applied to the vehicle when the vehicle travels is connected to the control circuit 8, and the control circuit 8 detects the vehicle based on the output signal from the acceleration sensor 14. Gradient information indicating the gradient of the road that is currently located can be acquired. The control circuit 8 corresponds to traveling road estimation means, storage control means, and notification control means. Further, the acceleration sensor 14 corresponds to an inclination degree acquisition unit.

  The in-vehicle navigation device 100 configured as described above performs the above-described map display processing, route calculation processing, route guidance processing, connection road estimation processing described later, and the like when an accessory power supply (not shown) is turned on and power is supplied. Execute. Since map display processing, route calculation processing, and route guidance processing are known, detailed description thereof is omitted here.

[Description of connected road estimation processing]
Next, the connection road estimation process executed by the control circuit 8 of the vehicle-mounted navigation device 100 will be described with reference to the flowchart of FIG. 2 and FIG. FIG. 3 (a) is a view of a parallel road composed of a general road and an elevated road running parallel therewith, and a connecting road connecting these parallel roads as seen from above, and FIG. 3 (b). These are the figures which looked at the parallel running road and the connecting road from the side.

  This processing is executed independently from map display processing, route calculation processing, route guidance processing, and the like while an accessory power supply (not shown) is turned on and power is supplied to the vehicle-mounted navigation device 100.

  First, in the first step 110 (hereinafter, “step” is simply referred to as “S”), (a) the time measurement for a predetermined time is started and (b) whether the vehicle is traveling on a parallel road. Judging. The predetermined time is set on the assumption that gradient information is acquired for each predetermined distance when the vehicle travels on a parallel road at an average speed. In this embodiment, the vehicle travels in parallel. The predetermined time is set to 2 seconds so that the gradient information is acquired every time the vehicle travels about 30 m. “Parallel road” refers to a road that approaches and runs parallel at different altitudes, and includes, as illustrated in FIG. 3, a general road and an elevated road that runs parallel above it. Further, in this embodiment, a road connecting the two parallel running roads from one side to the other side is defined as a connection road. As an example, as illustrated in FIG. 3A and FIG. 3B, a “general road” that is a road including points A, B, C, and D and points E, F, G, and H Since the "overpass road" that is the road that includes the road is approaching and running in parallel at different altitudes, the "connection road" that is the road that includes the point I is installed in order for the vehicle to move from the general road to the elevated road. It is such a state.

Here, (b) whether or not the vehicle is traveling on a parallel road is determined as follows.
(B-1) The travel road on which the vehicle travels and the current position of the vehicle are estimated. Specifically, first, the vehicle calculated based on the travel distance and the direction change obtained by the vehicle speed sensor 4 and the gyroscope 3 from the road map information read from the storage medium such as a CD-ROM by the map data input device 6. A road whose degree of coincidence (approximate degree) of the road shape (road pattern) is within a predetermined range with respect to the travel locus is searched. If there is a road having a matching degree within a predetermined range, the road is estimated as a traveling road on which the vehicle travels, and the road is located on the road having the highest matching degree with respect to the traveling locus. The position closest to the latest current position calculated by the execution of the calculation process is determined as the current position of the vehicle. Note that if there is no road having a matching degree within a predetermined range with respect to the traveling locus of the vehicle, the latest current position calculated by executing the position calculation process is determined as it is as the current position of the vehicle.

  (B-2) It is determined from the road map information whether or not there is a road that approaches and moves parallel at different altitudes near the estimated road. If it does not exist here (S110: NO), it is determined that the vehicle is traveling on a road other than the parallel road. In this case, for example, when gradient information and position information are not stored in the temporary storage area of the external memory 9 such as at the start of this processing (S240: NO), until it is determined that the vehicle is traveling on a parallel road. The above S110 and S240 are repeated. When gradient information and position information are stored in the temporary storage area of the external memory 9 (S240: YES), “gradient information storage processing” is executed. The gradient information storage process will be described later. On the other hand, when there is a road approaching and running parallel at different altitudes near the estimated traveling road (S110: YES), it is determined that the vehicle is traveling on the parallel traveling road and the process proceeds to S120. .

  In subsequent S120, it is determined whether or not a predetermined time has elapsed since the start of timing. If the predetermined time has not elapsed (S120: NO), the process proceeds to S130. On the other hand, when the predetermined time has elapsed (S120: YES), the above-mentioned predetermined time is reset to start measuring the predetermined time again, and the "gradient information search process" of S140 to S170 is executed, and then S110 The process from S110 is executed again.

  Here, the gradient information search process of S140 to S170 will be described. First, gradient information indicating the gradient of the road where the vehicle is currently located is acquired from the output signal from the G sensor 14 (S140). Here, as an example of gradient information, as illustrated in FIG. 3, when a vehicle is traveling on a flat point on the road such as point A, point B, or point E, the gradient value at that point ( (Gradient information) is near zero, and when the vehicle is traveling at an inclined point such as point I, the gradient value at that point is, for example, 3 degrees. Next, the gradient information at the point where the vehicle is currently located is retrieved from the gradient information stored in the temporary storage area of the external memory 9 (S150). Specifically, it is determined whether or not there is gradient information at a point within a predetermined radius centered on the point where the vehicle is currently located in the gradient information stored in the temporary storage area of the external memory 9. to decide. However, for example, when moving from a general road to an elevated road via a connecting road, if the distance traveled on the elevated road is long, the gradient information at points belonging to the connecting road is deleted if the predetermined radius is too small. Therefore, it is necessary to set a predetermined radius according to the current situation. Here, when there is no gradient information at a point within a predetermined radius range centering on the point where the vehicle is currently located (S160: NO), the gradient information is displayed together with position information indicating the current position of the vehicle. It is stored in the temporary storage area of the memory 9 (S170). On the other hand, if it exists (S160: YES), the "gradient information comparison process" of S210 to S230 is executed. The gradient information comparison process will be described later.

  If it is determined in S120 that the predetermined time has not elapsed, the process proceeds to S130. In S130, the process differs depending on the number of times this step is executed after the connection road estimation process is started. That is, (c) When this step is executed for the first time after starting this connection road estimation process, information indicating the link where the vehicle is currently located is stored in the temporary storage area of the external memory 9. And it transfers to S110 and performs the process below S110 again.

  In addition, (d) If this step is executed for the second time or later after the start of this connection road estimation process, has the vehicle moved from the link located when the previous step was executed to another link? It is determined whether or not the information indicating the link stored in the temporary storage area of the external memory 9 when the previous step is executed matches the information indicating the link where the vehicle is currently located. Here, if they do not match (S130: NO), it is determined that the vehicle has not moved from the link located when the previous step was executed to another link, and the process proceeds to S110 and the processes from S110 onward are performed. Run again. On the other hand, if they match (S130: YES), it is determined that the vehicle has moved from the link located when the previous step was executed to another link, and the “gradient information storage process” of S180 to S200 is executed. . Thereafter, the process proceeds to S110, and the processes after S110 are executed again. At this time, the information indicating the link stored in the temporary storage area of the external memory 9 when this step is executed last time is deleted, and the information indicating the link where the vehicle is newly located is temporarily stored in the external memory 9. Store in the storage area.

  Here, the gradient information storage processing of S180 to S200 will be described. First, the gradient information acquired and temporarily stored when the vehicle is traveling on a parallel road is searched from the temporary storage area of the external memory 9 (S250). Next, the corresponding gradient information whose value is not near zero is searched, the corresponding gradient information is regarded as gradient information related to the connected road, and is read together with the position information and stored in the normal storage area of the external memory 9. (S260). Further, the gradient information and the position information stored in the temporary storage area of the external memory 9 are deleted (S270). And it transfers to S110 and performs the process below S110 again.

  Note that the “gradient information storage process” executed when the gradient information and the position information are stored in the temporary storage area of the external memory 9 in the previous S240 (S240: YES) is the gradient information of S180 to S200 described above. This is the same process as the storage process. Specifically, the processing contents of S250, S260, and S270 are the same as the processing contents of S180, S190, and S200, respectively.

  Next, when the gradient information stored in the temporary storage area of the external memory 9 in the previous S160 includes gradient information at the point where the vehicle is currently located (S160: YES), the “gradient information comparison” is executed. Processing (S210 to S230) will be described. First, of the gradient information stored in the temporary storage area of the external memory 9, the gradient information at the point where the vehicle is currently located is compared with the gradient information of the road where the vehicle is currently acquired acquired in S140 above ( S210). Here, when both do not correspond (S220: NO), it transfers to S110 as it is and performs the process below S110 again. On the other hand, when both coincide (S220: YES), it is estimated that the vehicle is traveling on the connecting road connecting the parallel roads. Note that the “matching” determination criterion may be defined in advance. For example, when the past gradient value at the point where the vehicle is currently located and the current gradient value are within ± 0.2 degrees of each other, for example, it is determined as “match”.

Thereafter, the process proceeds to S110, and the processes after S110 are executed again.
This process ends when the power supply to the vehicle-mounted navigation device 100 is stopped, for example, when an accessory power source (not shown) is turned off.

  Here, an application example in which this process is executed when the vehicle travels on a parallel road will be described. As illustrated in FIG. 3A and FIG. 3B, a “general road” that is a road including points A, B, C, and D and a road that includes points E, F, G, and H are “ A “connecting road”, which is a road including the point I, is installed in order for the vehicle to move from the general road to the elevated road, approaching and running parallel at different altitudes. In addition, about the connection road mentioned above, the road information does not exist in road map information. When the vehicle traveling on the general road enters the parallel running portion (point A in FIG. 3) of the general road, it is determined in this process that the vehicle is traveling on the parallel running road (S110: YES). In this case, a display indicating that the vehicle illustrated in FIG. 4A is traveling on a general road is displayed on the display device 10 by a map display process executed independently of this process. Is done. After that, when the vehicle moves from the general road to the elevated road via the connecting road, the general road and the elevated road approach each other at different heights, so the vehicle passes through the connecting road from the ordinary road. When traveling to an elevated road, the travel trajectory from point A to point G via point I and the point where the vehicle travels on a general road as it is from point A to point C to point C The traveling locus is similar, and it may be determined that the vehicle is traveling on the general road as it is even though the vehicle has moved from the general road to the elevated road via the connecting road. After that, for example, when the vehicle approaches a point where the distance between the general road and the elevated road is wide, such as point H, the vehicle travels on the elevated road from the judgment that the vehicle is traveling on the ordinary road until then. Change to the judgment that you are doing. Accordingly, the display on the display device 10 also shows that the vehicle illustrated in FIG. 4B is traveling on a general road, and the vehicle illustrated in FIG. 4C is an elevated road. To indicate that you are driving.

  As described above, when the vehicle travels on the parallel road, the gradient information search process is executed every predetermined time to acquire the gradient information, and the link on which the vehicle travels is changed (S130: YES) In the case of changing from the determination that the vehicle is traveling along the parallel portion of the parallel road to the determination that the vehicle is traveling in a portion other than the parallel portion (S110: NO), the gradient information storage process is executed. Gradient information at a point estimated as a connection road is stored in the normal storage area of the external memory together with position information.

  Further, when the vehicle travels again on the parallel road described above, the vehicle travels from the general road via the connecting road after entering the parallel road portion (point A in FIG. 3) of the general road. When the vehicle moves to the elevated road, it is determined in the gradient information search process that there is past gradient information at the point where the vehicle is currently located (S160: YES), and the gradient information comparison process is executed. Here, when the “past gradient information” and the “current gradient information” at the point where the vehicle is currently located match (S220: YES), it is estimated that the vehicle is traveling on the connecting road (S230). And the display in the display apparatus 10 is changed into what shows that the vehicle which illustrates in FIG.4 (d) is drive | working an elevated road.

In addition to the application example described above, this process can be applied to various forms of parallel roads as exemplified in FIGS. 5A to 5C.
[effect]
Thus, according to the in-vehicle navigation device 100 of the present embodiment, when the vehicle travels on a parallel road, the gradient information and the gradient information at the previous travel are approximately equal and the current position of the vehicle is not flat. Since it is estimated that the vehicle is traveling on the connection road, road map information on the connection road that connects the parallel roads approaching and paralleling at different altitudes is not included in the road map information. Even in this case, it is possible to estimate as much as possible that the vehicle has entered the connecting road.

  In addition, this makes it possible to easily maintain information on connected roads that are not included in the road map information, so that the convenience of the user can be improved without waiting for the upgrade date of the road map information by a map producer or the like. Can do.

[Another embodiment]
(1) In the connection road estimation process of the above embodiment, the estimation of the connection road is performed using the gradient value (gradient information) at the point where the vehicle is currently located. An average value may be calculated by acquiring a gradient value every time it passes, and the average value of the calculated gradient values may be used. In this way, the accuracy of connection road estimation can be increased.

  (2) Further, in the connection road estimation process, an average value of gradient values per predetermined travel distance traveled by the vehicle may be used. Further, the altitude value included in the output signal from the GPS receiver 5 may be used instead of the gradient information. Specifically, altitude information such as the altitude value at the location where the vehicle is currently located, the average altitude value at that location, and the average altitude value per predetermined travel distance traveled by the vehicle may be used. . Further, it may be estimated whether or not the vehicle is traveling on a connection road in consideration of at least one of gradient information and altitude information. Note that the GPS receiver 5 corresponds to an inclination degree acquisition unit when the altitude value is used as described above. Thus, even if the estimation of the connecting road is performed using the “inclination degree” including at least one of the gradient information and the altitude information, the same effect as the above-described embodiment is obtained.

  (3) Further, it is also possible to analyze a planar traveling locus using a change history of the turning direction of the vehicle and to estimate a more appropriate connection road in consideration of the analysis result. For example, as illustrated in FIG. 3, after a vehicle traveling on a general road enters a parallel running portion (point A in FIG. 3) of the general road, the vehicle moves from the general road to an elevated road via a connecting road. When the vehicle moves, the turning direction of the vehicle changes as “straight, straight, right, left, straight, straight”. If the slope information of the road part corresponding to the right turn and left turn part of the turning history indicates that the part is not flat, the road part is estimated as a connected road. is there. In addition, if the slope information of the road part corresponding to the straight part of the turning history indicates that the part is not flat, the undulating part of either the general road or the elevated road, not the connecting road And so on. In this way, the accuracy of connection road estimation can be increased.

  (4) In the connection road estimation process of the above embodiment, while the vehicle is traveling on the parallel road, the gradient information is stored in the temporary storage area of the external memory 9 every predetermined time. For example, gradient information at a point other than a predetermined range from the current position of the vehicle may be deleted from the temporarily stored gradient information. In this way, the amount of gradient information stored in the temporary storage area can be reduced as compared with the case where the gradient information is stored while the vehicle is traveling on a parallel road. The capacity can be reduced.

  In the connection road estimation process of the above embodiment, the gradient information is stored in the temporary storage area of the external memory 9 every predetermined time. However, the present invention is not limited to this. For example, the gradient information is stored every predetermined distance in the external memory 9. May be stored in the temporary storage area. Even if it does in this way, there exists an effect similar to the said Example.

  (5) In the connection road estimation process of the above embodiment, the gradient information storage process (S180 to S200) is executed when the link on which the vehicle travels is changed (S130: YES). However, the present invention is not limited to this. For example, the gradient information storage process may be executed when it is determined by the map matching process that the vehicle has moved from a general road to an elevated road. Even if it does in this way, there exists an effect similar to the said Example. Further, the gradient information storage process may be executed every predetermined traveling distance or every predetermined time. Even if it does in this way, there exists an effect similar to the said Example.

  (6) In the gradient information storage process (S180 to S200, S250 to S270) of the connected road estimation process of the above embodiment, when the gradient information of the road portion that is not flat is retrieved and stored in the normal storage area of the external memory 9 However, the present invention is not limited to this, and for example, the gradient information at a point within a predetermined range from the current position of the vehicle may be the search target. In this way, the search target can be made smaller than when the gradient information in the entire parallel road is used as the search target, so the burden on the control circuit 8 that executes this process can be reduced.

  (7) In the gradient information search process (S140 to S170) of the connection road estimation process of the above embodiment, it is determined whether or not there is gradient information at a point within a predetermined radius centered on the point where the vehicle is currently located. However, the present invention is not limited to this, and when there is a road portion that is not flat other than the connecting road, gradient information on the road portion may be excluded by another method. For example, it may be determined whether or not there is gradient information at a point within a predetermined moving distance from the point where the vehicle is currently located. However, in this case as well, for example, when moving from a general road to an elevated road via a connecting road, when the distance traveled on the elevated road is long, if the predetermined moving distance is too small, the connecting road In some cases, gradient information at points belonging to is deleted, so it is necessary to set a predetermined movement distance according to the current situation. Even if it does in this way, there exists an effect similar to the said Example.

  (8) In the above embodiment, the temporary storage area of the external memory 9 is composed of a non-volatile memory. However, the present invention is not limited to this, and the temporary storage area holds the stored contents until the gradient information storage process is executed. Therefore, the temporary storage area may be constituted by a volatile memory. In this way, when executing the gradient information search process and the gradient information storage process in the connection road estimation process, the access speed to the temporary storage area of the external memory 9 can be increased.

It is a block diagram showing the structure of the vehicle-mounted navigation apparatus of an Example. It is a flowchart which shows the connection road estimation process which the control circuit of the vehicle-mounted navigation apparatus of an Example performs. (A) is the figure which looked at the parallel road which consists of a general road and the elevated road which parallels the upper direction, and the connection road which connects these parallel roads from the upper direction, (b) is a parallel road and connection It is the figure which looked at the road from the side. It is a display example in case the display apparatus of the vehicle-mounted navigation apparatus of an Example displays the present position of a vehicle, (a) is general among the parallel running roads which consist of a general road and the elevated road which parallels the upper direction. (B) is a display example when a vehicle is traveling on a road, and (b) shows that the vehicle passes through a parallel running portion of a general road of parallel roads including a general road and an elevated road running parallel to the upper side. FIG. 5C is a display example when the vehicle continues to travel on a general road, and FIG. 5C shows a parallel running portion of the elevated road of the parallel road composed of the general road and the elevated road running parallel above the vehicle. Is a display example when the vehicle continues to travel on the elevated road, and (d) is an elevated road of the parallel roads composed of the general road and the elevated road running parallel to the upper side. Display example when traveling A. It is a figure which shows the other form of the connection road which connects a parallel road, (a) is a general road from the left end of the general road of the parallel road which consists of a general road and the elevated road which parallels the upper direction of it. It is the figure which looked at the connection road which passes the upper part and the lower part of the elevated road, and connects with the right end of the elevated road from the upper part, (b) is a parallel running road consisting of a general road and an elevated road running parallel to the upper part. It is the figure which looked at the connecting road which passes under the elevated road from the right end of our ordinary road and connects to the right end of the elevated road from above, and (c) is from the elevated road running parallel to the ordinary road It is the figure which looked at the connection road which passes the upper direction of a general road from the left end of the general road of the parallel roads and connects with the left end of an elevated road from the upper side.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Position detector, 2 ... Geomagnetic sensor, 3 ... Gyroscope, 4 ... Distance sensor (vehicle speed sensor), 5 ... GPS receiver, 6 ... Map data input device, 7 ... Operation switch group, 8 ... Control circuit, 9 ... External memory, 10 ... Display device, 11 ... External information input / output device, 12 ... Remote control sensor, 13 ... Remote control, 14 ... Acceleration sensor (G sensor), 100 ... In-vehicle navigation device

Claims (6)

Current position detecting means for detecting the current position of the vehicle;
Road map information storage means for storing road map information;
Travel road estimation means for estimating a travel road on which the vehicle travels based on the current position of the vehicle detected by the current position detection means and the road map information stored in the road map information storage means;
An inclination degree acquisition means for acquiring an inclination degree at a point where the vehicle is currently located when the vehicle travels on one of the parallel roads approaching and paralleling at different altitudes;
When it is estimated that the vehicle is traveling on one of the parallel roads by the traveling road estimation unit, it is determined that the current position of the vehicle is not flat based on the inclination degree acquired by the inclination degree acquisition unit. Storage control means for storing the inclination degree in the inclination degree storage means together with position information indicating the current position of the vehicle;
A connected road estimation device comprising:
Further, the travel road estimation means estimates the slope degree when the slope degree storage means stores the slope degree at the current position of the vehicle when it is estimated that the vehicle is traveling on one of the parallel roads. The vehicle is running on a connecting road that connects one of the parallel roads and the other of the parallel roads when the read slope degree and the slope degree acquired by the slope degree acquisition means are substantially equal. A connected road estimation device characterized by Current position detecting means for detecting the current position of the vehicle;
Road map information storage means for storing road map information;
Traveling road estimation means for estimating a traveling road on which the vehicle travels based on the current position of the vehicle detected by the current position detection means and the road map information stored in the road map information storage means;
An inclination degree acquisition means for acquiring an inclination degree at a point where the vehicle is currently located when the vehicle travels on one of the parallel roads approaching and paralleling at different altitudes;
When it is estimated that the vehicle is traveling on one of the parallel roads by the traveling road estimation means, the inclination degree acquired by the inclination degree acquisition means is inclined together with position information indicating the current position of the vehicle. Storage control means for storing the degree storage means;
A connected road estimation device comprising:
Further, the travel road estimation means estimates the slope degree when the slope degree storage means stores the slope degree at the current position of the vehicle when it is estimated that the vehicle is traveling on one of the parallel roads. When the read inclination degree and the inclination degree acquired by the inclination degree acquisition means are substantially equal and the current position of the vehicle is determined to be not flat based on the inclination degree, one of the parallel running roads It is estimated that the vehicle is driving | running the connection road which connects the other of the said parallel roads. The connection road estimation apparatus characterized by the above-mentioned. In the connection road estimation device according to claim 1 or 2,
The inclination degree acquisition means is configured to acquire at least one of a gradient value or an altitude value at a point where the vehicle is currently located, and calculate the inclination degree based on at least one of the acquired gradient value or altitude value. A connected road estimation device. In the connection road estimation device according to any one of claims 1 to 3,
The memory control means, when it is estimated that the vehicle is not traveling on the parallel road after the travel road estimation means is estimated that the vehicle is traveling on one of the parallel roads, A connected road estimation device that deletes the slope degree at a point outside the predetermined range from the current position of the vehicle among the slope degrees stored in the slope degree storage means. The connection road estimation device according to any one of claims 1 to 4,
Road map information including the current position of the vehicle detected by the current position detection means in the connected road estimation device and the connected road where the vehicle is estimated to be traveling by the traveling road estimation means in the connected road estimation device. Notification control means for informing the notification means;
A navigation device comprising:   A program for causing a computer to function as a traveling road estimation unit and a storage control unit in the connection road estimation device according to any one of claims 1 to 4.

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