JP2012021928A - Car navigation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a car navigation apparatus capable of calculating a correct present position.SOLUTION: When a vehicle runs a specific lane 120 which may reach a branch road 130 if the vehicle runs without changing the lane and turns to the branch road 130, display candidate points are calculated on an escape link 171 concerned with the branch road 130. When calculating an error cost value ec of the display candidate points, a value of a coefficient γ is reduced. Since a reliability trst of the display candidate points is improved, a correct present position can be easily calculated.

Description

  The present invention relates to a technique for estimating a current position of a vehicle.

  A car navigation device that corrects the current position of the vehicle by performing a map matching process when calculating the current position of the vehicle is known. In this car navigation device, when the map matching process is performed, the car currently travels on a road where the angle difference between the detected traveling direction of the vehicle and the extending direction of the road stored as map data is a predetermined value or less. Selected as a candidate for the road. However, when traveling on a branch road, if the angle difference in the extending direction between the roads after branching is small, that is, if the branch angle difference is small, the road is currently traveling on a road different from the road on which it actually travels. There is a risk of selecting as a candidate road. Therefore, a car navigation device that selects a candidate for a road that is currently running by considering the width of the road is known (see Patent Document 1).

JP 2005-114632 A

  However, in the conventional car navigation device, even if the width of the road is taken into consideration, depending on the branch road, there is a possibility that a road different from the road that is actually running is selected as a candidate for the road that is currently running.

  The car navigation device according to the first aspect of the present invention includes position detection means for detecting a provisional current position of a vehicle, road data storage means for storing road map data representing a road using a plurality of nodes and links, and position detection. Current position candidate point calculating means for calculating a plurality of candidate points for the fixed current position of the vehicle based on the provisional current position detected by the means and the road map data stored in the road data storage means; and current position candidate points For each of a plurality of candidate points at the fixed current position of the vehicle calculated by the calculation means, a reliability calculation means for calculating the reliability representing the reliability as the fixed current position of the vehicle, and a reliability among the plurality of candidate points A fixed current position determining means for determining the candidate point having the highest degree as the fixed current position of the vehicle, and the road map data is stored in the vehicle when traveling without changing the lane. Whether or not branch information is included in the road map data for the road ahead of the road on which the vehicle is traveling, including branch information indicating that there is a specific lane that will lead to the branch road from Branch information detecting means for judging, lane recognition means for recognizing the lane of the road on which the vehicle is traveling, lane coincidence judging means for judging whether or not the lane recognized by the lane recognition means matches the specific lane And the reliability calculation means detects lane recognition means when the branch information detection means detects that branch information is included in the road map data for the road ahead of the road on which the vehicle is traveling. When the lane coincidence determining means determines that the recognized lane matches the specific lane, correction is performed to increase the reliability calculated for the candidate points related to the branch road among the plurality of candidate points. .

  According to the present invention, a correct current position can be calculated.

It is a figure which shows the structure of the navigation apparatus by this invention. It is a figure which shows an example of the road which has a specific lane and a branch road, (a) is a figure of description of a lane, (b) is a figure which shows the node and link of this road. It is the flowchart which showed the operation | movement of the present position detection process. It is a subroutine of the reading process of the bipolar information in the flowchart showing the operation of the current position detecting process. It is a subroutine for reliability calculation in the flowchart showing the operation of the current position detection process. It is a figure which shows transition of the display of the own vehicle position mark displayed on a display monitor, (a) shows the case where this invention is applied, (b) shows the case where this invention is not applied.

  With reference to FIGS. 1-6, one Embodiment of the car navigation apparatus by this invention is described. FIG. 1 is a diagram showing a configuration of a navigation apparatus 1 according to the present invention. The navigation device 1 is mounted on a vehicle, displays the current position of the vehicle on a road map, and guides the vehicle to a destination. At this time, a known map matching process is performed based on the road map data so that the current position of the vehicle can be displayed on the road map. The navigation device 1 shown in FIG. 1 includes a control circuit 11, a ROM 12, a RAM 13, a sensor group 14, an image memory 15, a display monitor 16, an input device 17, a map data storage device 18, and a lane detection device 19.

  The control circuit 11 includes a microprocessor and its peripheral circuits, and executes various processes based on a control program and road map data stored in the ROM 12 or the map data storage device 18 using the RAM 13 as a work area. For example, the control circuit 11 searches for a destination when setting a destination, searches for a recommended route to the set destination, detects the current position of the vehicle, various image display processing, and route guidance Various processes necessary for the navigation device 1 to operate, such as the voice output process, are executed.

  The sensor group 14 is a sensor group for detecting the current position of the host vehicle. For example, the vibration gyro sensor 14a for detecting the angular velocity of the host vehicle, the vehicle speed sensor 14b for detecting the vehicle speed, and a GPS satellite are used. It consists of various sensors such as a GPS sensor 14c for receiving GPS signals. The navigation device 1 can obtain the current position of the vehicle by executing a detection process of the current position of the vehicle in the control circuit 11 based on each sensor signal from the sensor group 14.

  The image memory 15 is a memory for temporarily storing image data to be displayed on the display monitor 16. The image data stored in the image memory 15 includes map drawing data for displaying a road map, various graphic data, and the like, and is controlled based on road map data recorded in the map data storage device 18. This is created by image display processing executed by the circuit 11. The display monitor 16 is configured using a liquid crystal display or the like, and displays various images such as a road map based on the image data stored in the image memory 15 and presents it to the driver of the vehicle. The display monitor 16 is installed at a position that is easy for the driver to see, such as a dashboard or an instrument panel.

  The input device 17 includes various input switches for a driver to perform various input operations for operating the navigation device 1. The driver operates the input device 17 to input, for example, the name of a facility or point desired to be set as a destination, select a destination from registered locations registered in advance, or scroll the map. Can be. The input device 17 is realized by, for example, an operation panel, a remote control, a touch panel integrated with the display monitor 16 or the like.

  The map data storage device 18 is a device for storing road map data and various control programs. As the map data storage device 18, for example, a hard disk drive device, an optical disk such as a DVD-ROM or a CD-ROM, its drive device, a nonvolatile semiconductor memory such as a flash memory, or the like is used. The road map data stored in the map data storage device 18 includes the route calculation data used for the route search to the destination, the intersection name, the road name, and the like according to the selected guidance route. Route guidance data used for guidance, road data representing roads, and the like are included. The road map data includes background data representing map shapes other than roads, such as rivers, railways, various facilities on the map (landmarks), and the like.

  The lane detection device 19 is a device for detecting the lane of the road on which the vehicle is traveling, based on the operation state of the vehicle and an image obtained by imaging with a camera. The lane detection device 19 performs processing for recognizing which lane of a plurality of lanes the vehicle is traveling based on the camera 19a and image data captured and acquired by the camera 19a. A lane recognition device 19b is provided.

  When the user operates the input device 17 to set a destination, the navigation device 1 searches for a recommended route to the destination by performing a predetermined algorithm calculation based on the above-described route calculation data. Then, the vehicle is guided to the destination according to the searched recommended route while displaying the road map around the current position of the vehicle. At this time, the current position of the vehicle is obtained by executing detection processing of the current position of the vehicle as will be described later in the control circuit 11.

--- About road map data ---
In the road map data, the smallest unit representing a road section is called a link, and each road is composed of a plurality of links. A point connecting links, that is, an end point of each link is called a node. The information of each node in the road map data includes position information (coordinate information). In the link, a point called a shape interpolation point may be set between the nodes as needed. The information of each shape interpolation point in the road map data includes position information (coordinate information) as in the case of the node. The shape of each link, that is, the shape of the road is determined by the position information of the node and the shape interpolation point. Thus, in the road map data stored in the map data storage device 18, the road is represented using a plurality of nodes and links.

  Of the nodes corresponding to the connection points between the link representing the main line and the link representing the branch road for the road where the branch road from the main line exists, the node for the road having the lane as shown in FIG. The information includes the following bifurcation information (branch information). In a road having lanes as shown in FIG. 2A, there are a plurality of lanes (for example, three lanes on one side) on the road before the branch road 130 branches from the main line 110, and some of the lanes In this lane (the leftmost lane in FIG. 2A), the vehicle reaches the branch road 130 when traveling without changing the lane. In the following description, the lane that leads to the branch road 130 when the vehicle travels without changing the lane is referred to as a specific lane 120. Of the main lines 110, the main line 110 before the branch path 130 branches is referred to as a main line 111 before branching, and the main line 110 after the branch path 130 branches is referred to as a main line 112 after branching.

  Nodes and links on the road shown in FIG. 2A are shown in FIG. FIG. 2B shows a node 150 corresponding to a point where the branch path 130 branches from the main line 110 and links 161, 162, and 171 connected to the node 150. The link 161 is a link representing the main line 110 before the node 150 (the main line 111 before branching). The link 162 is a link representing the main line 110 (the main line 112 after branching) ahead of the node 150. The link 171 is a link representing the branch path 130 and is called an escape link 171.

For example, the following information is included in the vibration information in the node 150 shown in FIG.
(1) Information on presence / absence of specific lane 120 (information indicating that specific lane 120 exists)
(2) Information indicating whether the specific lane 120 exists on the left or right side of the main line (information indicating that the specific lane 120 exists on the left side of the main line 110)
(3) Link ID for identifying the exit link 171 of the branch path 130 connected to the node 150

That is, in general, the following information is included in the bipolar information.
(1) Information on presence / absence of specific lane (2) Information on whether specific lane exists on the left or right side of main line when there is a specific lane (3) Branch connected to a node having bifurcation information Link ID to identify the link (escape link) of the road

  In the present embodiment, the localization information is used in the process for detecting the current position of the vehicle. Specific contents regarding the use of the bifaction information will be described in detail later.

--- Current position detection process ---
Processing for detecting the current position of the vehicle executed in the control circuit 11 will be described below. In order to display the current position of the vehicle in a superimposed manner on the road map near the current position displayed on the display monitor 16, the navigation apparatus 1 according to the present embodiment calculates (detects) the current position by the following process. ing. FIG. 3 is a flowchart showing the operation of the current position detection process. For example, when the navigation apparatus 1 is turned on, for example, when an accessory is turned on (ACC ON) by an ignition key (not shown) of the vehicle, a program for performing the process shown in FIG. 3 is periodically started.

  The control circuit 11 reads data from the vibration gyro sensor 14a and the vehicle speed sensor 14b (step S1). In addition, reading processing of the bi- scription information described later is performed. The control circuit 11 determines whether or not the vehicle is traveling straight based on the read data from the vibration gyro sensor 14a and the vehicle speed sensor 14b (step S3). If it is determined that the vehicle is traveling straight (Yes in step S3), the moving amount of the vehicle is calculated by calculating the traveling direction of the vehicle and the traveling distance of the vehicle based on the read data. Then, starting from the current position of the vehicle calculated last time, a point estimated to be present is calculated by adding the movement amount of the vehicle calculated this time (step S5). Let this point be the estimated current position (provisional current position).

  Note that, for example, immediately after the navigation device 1 is started, the vehicle current position calculated and stored immediately before the navigation device 1 is stopped last time or a previously set point is set as the vehicle current position previously calculated. Perform the process.

After calculating the estimated current position as described above, a current position candidate is calculated as follows. The control circuit 11 searches and extracts a link (candidate link) satisfying both of the following (a) and (b) from the road map data stored in the map data storage device 18 (step S7).
(A) The difference between the vehicle travel direction calculated when calculating the estimated current position and the link direction (link direction) of the road map data is equal to or less than a predetermined value.
(B) The length of the line segment dropped from the estimated current position perpendicularly to the link is not more than a predetermined value.
The link direction is calculated by reading the position coordinates of the nodes located at both ends of the link from the road map data.

  It is determined whether or not the above-described candidate link exists, and if it is determined (Yes in step S9), the vehicle current calculated in the previous process is calculated by the vehicle travel distance calculated when calculating the estimated current position. A point moved from the position along the link is set as a candidate for the current position (step S11). The current position candidate obtained in this way is called a display candidate point. When it is determined that there is no link satisfying the above-described (a) and (b) (No at Step S9), a dead reckoning process (Step S19) described later is executed.

  In the above-described processing, since a plurality of candidate links and display candidate points are extracted, the reliability trst representing the certainty (credibility) as the road on which the vehicle is actually traveling is calculated for each display candidate point. (Step S13). The calculation process of the reliability trst will be described in detail later. When the reliability trst is calculated for each display candidate point, the display candidate point with the highest reliability trst is selected (step S15). Then, the selected display candidate point is displayed on the display monitor 16 together with the surrounding road map as the current position of the vehicle (step S17). In this way, the process of extracting the candidate link and determining the display candidate point having the highest reliability trst as the current position of the vehicle is generally called map matching. In addition to the display candidate point having the highest reliability trst, the position of the display candidate point other than the display candidate point having the highest reliability trst is also stored, and the estimated current position of the display candidate point is next processed. The reliability trst is calculated as a starting point for the calculation.

  After reading the data from the vibration gyro sensor 14a and the vehicle speed sensor 14b (Step S1), when it is determined that the vehicle is turning (No at Step S3), or when the above (a) and (b) are performed. When it is determined that there is no link to be satisfied (No in step S9), a known dead reckoning process is performed (step S19). That is, the moving amount of the vehicle is calculated by calculating the traveling direction of the vehicle and the traveling distance of the vehicle based on the read data. Then, a point obtained by adding the currently calculated vehicle movement amount to the previously calculated vehicle current position is displayed as a vehicle current position (step S19) on the display monitor 16 together with the surrounding road map. (Step S17).

  As described above, the display candidate point having the highest reliability trst and the current position of the vehicle calculated by the known dead reckoning process are the current position of the vehicle finally determined in the navigation device 1. Therefore, the current position of the vehicle determined in this way is also referred to as a determined current position.

--- About calculation of reliability trst ---
The reliability trst is calculated based on the absolute value (direction difference) Δθ of the difference between the calculated traveling direction of the vehicle and the link direction of the road map data, and the distance between the estimated current position and the display candidate point, that is, the estimated current position. It is calculated based on the length (perpendicular distance) L of the line segment dropped perpendicularly to the candidate link. Specifically, it is calculated as follows.

The error cost value ec defined by the equation (1) is calculated from the azimuth difference Δθ and the perpendicular distance L.
ec = γ × (α × Δθ + β × L) (1)
In the equation (1), α, β, and γ are coefficients. γ will be described in detail later.

Next, the accumulated error cost es is calculated. The accumulated error cost es is calculated as follows based on the accumulated error cost es _n−1 calculated in the previous process and the currently calculated error cost value ec.
es = (1−k) × es _n−1 + k × ec (2)
Here, k is a weighting factor. The accumulated error cost es represents how much the error cost calculated in the previous process is reflected in the error cost calculated in the current process.

The smaller the azimuth difference Δθ and the shorter the perpendicular distance L, the closer to zero the error cost value ec and the accumulated error cost es determined by the equations (1) and (2). That is, the higher the credibility as the actual vehicle position is, the closer the error cost value ec and the accumulated error cost es obtained by the equations (1) and (2) approach to zero. However, since the higher the reliability as the actual vehicle position, the easier it is to understand that the value of the reliability trst increases, the reliability trst is defined by equation (3).
trst = 100 / (1 + es) (3)
Accordingly, the reliability trst value approaches 100 as the reliability as the actual vehicle position increases, and the reliability trst approaches 0 as the reliability as the actual vehicle position decreases.

--- Conventional problems in calculation of reliability trst ---
As described above, the reliability trst is calculated based on the traveling direction and traveling distance of the vehicle calculated by the traveling of the vehicle and the road map data. Therefore, for example, when the difference in the link direction between the branch road that branches off from the main line and the main line is small, the confirmed current position may be erroneously detected as being on a different road from the road that is actually traveling. There is.

--- Calculation of reliability in the present embodiment ---
Therefore, in the navigation device 1 of the present embodiment, for example, as shown in FIG. 2, when it is determined that the vehicle is traveling in a specific lane on a road having the specific lane described above on the main line before the branch. The value of the coefficient γ is reduced when calculating the error cost value ec of the display candidate point belonging to the branch link (exit link) of the branch path. As a result, the error cost value ec is reduced (that is, the reliability trst is increased), and the correct current position is easily detected correctly as being on the branch road that is actually running.

  Specifically, in navigation device 1 of the present embodiment, it is determined whether the vehicle is traveling in a specific lane by the following process. When it is determined that the vehicle is traveling in a specific lane, the link ID of the escape link is stored. Thereafter, when calculating the error cost value ec of the display candidate point belonging to the link that matches the stored link ID, the value of the coefficient γ is reduced to calculate the reliability trst.

(A) Bifurcation Information Reading Process FIG. 4 is a subroutine (Step S2 in FIG. 3) for reading the bi- cation information in the flowchart showing the operation of the current position detecting process described above. When the control circuit 11 reads the data from the vibration gyro sensor 14a and the vehicle speed sensor 14b as described above (step S1 in FIG. 3), the link to which the determined current position calculated last time belongs and the link connected to this link are displayed on the vehicle. In the case of following forward in the traveling direction, it is determined whether or not there is a node having the above-described bi-functional information within a predetermined distance (for example, 300 m) with a link length from the previously determined final position. (Step S201).

  If it is determined that there is no node having the bipolar information within a predetermined distance of the link length from the previously determined fixed current position (No in step S201), the processing in this subroutine is terminated, and the main routine (FIG. 3) is completed. Return to step S3). If it is determined that there is a node having the bipolar information within a predetermined distance in the link length from the determined current position calculated last time (Yes in step S201), the link ID of the outgoing link included in the bipolar information related to the node Is already stored in a predetermined storage area of the RAM 13 (step S203).

  If it is determined that the link ID of the escape link included in the bi-function information related to the node is not stored in the predetermined storage area of the RAM 13 (No determination in step S203), the bi-directional information related to the node is read (step S203) S205). And the information of the lane in which the vehicle drive | worked obtained with the lane detection apparatus 19 is read (step S207).

  The information indicating whether the specific lane exists on the left or right side of the main line included in the read vibration information is compared with the information on the lane in which the vehicle travels, which is read from the lane detection device 19, and the vehicle is in the specific lane. Whether or not the vehicle is traveling is determined (step S209).

  For example, when the read lane information includes information that the specific lane exists on the left side of the main line and the lane detection device 19 detects that the vehicle is traveling on the leftmost lane, the vehicle is specified. Determine that you are driving in a lane. Further, when the read lane information includes information that the specific lane exists on the right side of the main line and the lane detection device 19 detects that the vehicle is traveling on the rightmost lane, the vehicle is specified. Determine that you are driving in a lane.

  In addition, for example, the read lane information includes information that the specific lane exists on the left side of the main line, and the lane detection device 19 detects that the vehicle is traveling in a lane other than the leftmost lane. In this case, it is determined that the vehicle is not traveling in the specific lane. In addition, when the read lane information includes information that the specific lane exists on the right side of the main line and the lane detection device 19 detects that the vehicle is traveling in a lane other than the rightmost lane, It is determined that the vehicle is not traveling in a specific lane.

  If it is determined that the vehicle is traveling in a specific lane (Yes determination in step S209), the information indicating whether the specific lane exists on the left or right of the main line and the link ID of the escape link included in the read bi- cation information Are stored in a predetermined storage area of the RAM 13 (step S211), the processing in this subroutine is terminated, and the process returns to the main routine (step S3 in FIG. 3).

  If it is determined that the vehicle is not traveling in the specific lane (No in step S209), the processing in this subroutine is terminated, and the process returns to the main routine (step S3 in FIG. 3).

  If it is determined that there is a node having the localization information (Yes in step S201), the link ID of the escape link included in the localization information related to the node is already stored in the predetermined storage area of the RAM 13. If it is determined (Yes at Step S203), information on the lane in which the vehicle travels obtained by the lane detector 19 is read (Step S213). Then, the information indicating whether the specific lane exists on the left or right side of the main line stored in a predetermined storage area of the RAM 13 is compared with the information on the lane in which the vehicle travels read from the lane detection device 19. Then, it is determined whether or not the vehicle is traveling in a specific lane (step S215).

  When it is determined that the vehicle is not traveling in the specific lane (No in step S215), information indicating whether the specific lane exists on the left or right of the main line and an escape link stored in a predetermined storage area of the RAM 13 Is deleted (step S217), the processing in this subroutine is terminated, and the process returns to the main routine (step S3 in FIG. 3).

  If it is determined that the vehicle is traveling on a specific lane (step S215: affirmative determination), the processing in this subroutine is terminated, and the process returns to the main routine (step S3 in FIG. 3).

(B) Reliability Calculation Processing FIG. 5 is a reliability calculation subroutine (step S13 in FIG. 3) in the flowchart showing the operation of the current position detection processing described above. After calculating the display candidate points as described above (step S11 in FIG. 3), the control circuit 11 selects any one of the calculated display candidate points (step S131). In the following description, the display candidate point is referred to as a selection display candidate point. Then, it is determined whether or not the link to which the selection display candidate point belongs is an escape link whose link ID is stored in the RAM 13 described above (step S133).

  When the link to which the selected display candidate point belongs is an escape link in which the link ID is stored in the RAM 13 (Yes in step S133), the value of the coefficient γ in the above-described equation (1) is reduced by a predetermined ratio. The error cost value ec, the accumulated error cost es, and the reliability trst are calculated (step S137).

  If it is determined that the link to which the selected display candidate point belongs is not an escape link in which the link ID is stored in the RAM 13 (No in step S133), the value of the coefficient γ in the above-described equation (1) is reduced. Without doing so, the error cost value ec, the accumulated error cost es, and the reliability trst are calculated (step S139).

  The above-described processing is sequentially executed for all display candidate points (No determination in step S137). When the reliability trst is calculated for all display candidate points (Yes in step S137), the process in the reliability calculation subroutine is terminated, and the process returns to the main routine (step S15 in FIG. 3).

  In the navigation device 1 configured in this way, for example, when the vehicle travels on the specific lane 120 on the road shown in FIG. 2A and goes to the branch road 130 as it is, the escape link 171 related to the branch road 130. When the display candidate point is calculated above, the value of the coefficient γ is reduced when the error cost value ec of the display candidate point is calculated. As a result, the reliability trst of the display candidate point is increased, so that the correct current position can be easily calculated. Therefore, the car mark (own vehicle position mark) indicating the determined current position of the vehicle displayed on the display monitor 16 is easily displayed at the correct position as shown in FIG.

  FIG. 6A shows the navigation device 1 according to the present embodiment, when the vehicle travels on the road shown in FIGS. 2A and 2B and travels along the specific lane 120 toward the branch road 130. It is a figure which shows transition of the display of the own vehicle position mark 181 displayed on the monitor. In FIG. 6A, the links 161, 162, 171 and the node 150 represented by broken lines are not displayed on the display monitor 16. The same applies to FIG. 6B described later.

  In the navigation device 1 according to the present embodiment, the host vehicle position mark 181 displayed on the display monitor 16 changes in order from 181a to 181b, 181c,. That is, the vehicle position mark 181 displayed on the display monitor 16 is displayed so as to overlap the escape link 171 before the position of the node 150. Thus, in the navigation device 1 according to the present embodiment, the transition state of the vehicle position mark 181 is close to the actual behavior of the vehicle.

    FIG. 6B is a conventional navigation device to which the present invention is not applied. When the vehicle travels on the road shown in FIGS. 2A and 2B and travels on a specific lane 120 toward the branch road 130, It is a figure which shows transition of the display of the own vehicle position mark 182 displayed on the display monitor 16. FIG. In the conventional navigation apparatus to which the present invention is not applied, the host vehicle position mark 182 displayed on the display monitor 16 may change from 182a to 182b, 182c,. is there. As described above, in the conventional navigation apparatus to which the present invention is not applied, the main line after branching in which the vehicle position mark 182 is represented on the display monitor 16 as in the transition from the vehicle position mark 182e to the vehicle position mark 182f. There is a risk of jumping from 112 to the branch path 130.

---- Modified example ---
(1) In the above description, when the vehicle travels in the specific lane 120 and goes directly to the branch road 130, when the display candidate point is calculated on the escape link 171 related to the branch road 130, the display candidate point Although the value of the coefficient γ is reduced when the error cost value ec is calculated, the present invention is not limited to this. For example, the coefficient α or the coefficient β in the expression (1) may be reduced, and the reliability trst calculated by the expression (3) is multiplied by a coefficient larger than 1 to increase the value of the reliability trst. Also good.

(2) In the above description, when the vehicle travels in the specific lane 120 and goes directly to the branch road 130, when the display candidate point is calculated on the escape link 171 related to the branch road 130, the display candidate point However, the present invention is not limited to this. For example, if the lane detector 19 detects that the vehicle is traveling on the main line 111 before branching instead of the specific lane 120, display candidate points are calculated on the link 162 related to the main line 112 after branching. You may comprise so that the reliability trst of the said display candidate point may be calculated with a big value.

(3) In the above description, when the vehicle travels in the specific lane 120 and goes directly to the branch road 130, when the display candidate point is calculated on the escape link 171 related to the branch road 130, the display candidate point However, the present invention is not limited to this. For example, when the vehicle travels on the specific lane 120 and goes to the branch road 130 as it is, when the display candidate point is calculated on the escape link 171 related to the branch road 130, the display candidate point is determined as the confirmed current position. You may comprise.

(4) In the above description, the lane detection device 19 is configured to recognize which lane the vehicle is traveling on the basis of image data acquired by being captured by the camera 19a. The invention is not limited to this. For example, instead of the camera 19a, the lane detection device 19 detects the distance to the side wall with an ultrasonic sensor, and based on the detected distance to the side wall, whether the vehicle is traveling in the rightmost lane, or It may be configured to recognize which lane the vehicle is traveling by determining whether or not the vehicle is traveling in the leftmost lane.

(5) The above description does not particularly mention the relationship between the recommended route to the destination and the lane on which the vehicle travels. For example, when traveling on a road as shown in FIGS. If the vehicle is traveling on a lane that leads to a road different from the road, a notification that there is a possibility of deviating from the recommended route may be made. That is, for example, when the main line 112 after branching shown in FIGS. 2 and 6 is included in the recommended route to the destination, if the lane recognized by the lane detection device 19 is the specific lane 120, it deviates from the recommended route. The control circuit 11 may be configured to control each unit so as to display a display indicating that there is a possibility of being displayed on the display monitor 16 or to notify the user by voice from a speaker (not shown). Further, for example, when the branch road 130 shown in FIGS. 2 and 6 is included in the recommended route to the destination, if the lane recognized by the lane detector 19 is not the specific lane 120, there is a risk of deviating from the recommended route. The control circuit 11 may be configured to control each unit so that a display to the effect is displayed on the display monitor 16 or is notified by voice from a speaker (not shown).

  When the main line 110 is an automobile-only road such as an expressway and the main line 110 is included in the recommended route to the destination, the main line 112 after branching shown in FIGS. 2 and 6 becomes the recommended route to the destination. Will be included. Therefore, in such a case, even if the lane recognized by the lane detector 19 is the specific lane 120, the recommended route as described above is used when the branch road 130 is a road that reaches the service area or the parking area. It is desirable not to notify that there is a risk of deviating from. Specifically, for example, when the branched main line 112 shown in FIGS. 2 and 6 is included in the recommended route to the destination, the road type included in the link information related to the main line 110 (main lines 111 and 112). Read the information. When the road type is an expressway or the like, if the branch road 130 is a road that reaches a service area or a parking area, even if the lane recognized by the lane detector 19 is the specific lane 120, It is desirable that the control circuit 11 controls each unit so as not to perform such notification.

(6) In the above description, the navigation device for in-vehicle use has been described. However, the navigation device according to the present invention is not limited to the in-vehicle use but can be applied to a navigation device mounted on a motorcycle or a bicycle.
(7) You may combine each embodiment and modification which were mentioned above, respectively.

  The present invention is not limited to the embodiment described above, and stores position detection means for detecting the provisional current position of the vehicle, and road map data representing a road using a plurality of nodes and links. Current position candidate points for calculating a plurality of candidate points for the determined current position of the vehicle based on the road data storage means, the provisional current position detected by the position detection means, and the road map data stored in the road data storage means A calculation means, a reliability calculation means for calculating reliability representing the credibility as the fixed current position of the vehicle for each of a plurality of candidate points of the fixed current position of the vehicle calculated by the current position candidate point calculation means; When the road map data is traveled without changing the lane, the vehicle is provided with a confirmed current position determining means for determining a candidate point having the highest reliability among the candidate points of Includes branch information indicating that there is a specific lane from which the vehicle reaches the branch road from the main line, and the road map data for the road ahead of the road on which the vehicle is traveling includes branch information. Branch information detecting means for judging whether there is a lane, lane recognition means for recognizing the lane of the road on which the vehicle is traveling, and a lane for judging whether the lane recognized by the lane recognition means matches the specific lane And further comprising a coincidence determination means, wherein the reliability calculation means detects that the branch information is included in the road map data for the road ahead of the road on which the vehicle is running, When the lane matching determination means determines that the lane recognized by the lane recognition means matches the specific lane, correction is performed to increase the reliability calculated for the candidate points related to the branch road among the plurality of candidate points. The It is intended to include car navigation devices for various structures that symptoms.

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 11 Control circuit 12 ROM 13 RAM
14 Sensor group 15 Image memory 16 Display monitor 17 Input device 18 Map data storage device 19 Lane detection device

Claims (4)

Position detecting means for detecting a provisional current position of the vehicle;
Road data storage means for storing road map data representing roads using a plurality of nodes and links;
Current position candidate point calculation for calculating a plurality of candidate points for the determined current position of the vehicle based on the provisional current position detected by the position detection means and the road map data stored in the road data storage means Means,
Reliability calculation means for calculating reliability representing the reliability as the determined current position of the vehicle for each of a plurality of candidate points of the determined current position of the vehicle calculated by the current position candidate point calculating means;
A confirmed current position determining means for determining, from among the plurality of candidate points, a candidate point having the highest reliability as a confirmed current position of the vehicle;
The road map data includes branch information indicating that there is a specific lane that leads to a branch road where the vehicle branches from the main line when traveling without changing lanes,
Branch information detecting means for determining whether or not the branch information is included in road map data about a road ahead of the road on which the vehicle is traveling;
Lane recognition means for recognizing the lane of the road on which the vehicle is traveling;
Lane match determination means for determining whether or not the lane recognized by the lane recognition means matches the specific lane;
When the branch information detecting means detects that the branch information is included in road map data for a road ahead of the road on which the vehicle is traveling, the reliability calculating means is configured to recognize the lane recognition means. When the lane coincidence determining means determines that the lane recognized in step 4 matches the specific lane, a correction for increasing the reliability calculated for the candidate point related to the branch road among the plurality of candidate points Car navigation device characterized by The car navigation device according to claim 1,
The lane recognition unit recognizes a lane of a road on which the vehicle is traveling based on information on a road image obtained from an external imaging device. In the car navigation device according to claim 1 or 2,
Recommended route calculation means to calculate the recommended route from the current location to the destination,
Main line judging means for judging whether or not the main line after the branch road is branched is included in the recommended route calculated by the recommended route calculating means;
The main line after the branch information detecting means detects that the branch information is included in the road map data about the road ahead of the road on which the vehicle is traveling, and the branch road is branched Is determined to be included in the recommended route calculated by the recommended route calculating means, and the lane matching determination is that the lane recognized by the lane recognition means matches the specific lane. A car navigation device, further comprising: an informing means for informing that the vehicle may deviate from the recommended route when judged by the means. The car navigation device according to claim 3,
The notification means detects that the branch information is included in the road map data for the road ahead of the road on which the vehicle is traveling, and the branch road branches. The main line determination means determines that the main line after being included in the recommended route calculated by the recommended route calculation means, and the lane recognized by the lane recognition means matches the specific lane. Even if it is determined by the lane coincidence determining means, if the branch road is a road that reaches a service area or a parking area, the notification is not performed.

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