JP4628249B2 - Navigation device - Google Patents

Description

The present invention relates to matching the position and the vehicle position of the road links the vehicle position to the navigation apparatus having a map matching function to correct displayed on the road link.

  In general, in-vehicle navigation devices detect the current position of a vehicle using a self-contained navigation sensor, a GPS (Global Positioning System) receiver, and the like, read map data in the vicinity from a recording medium, and display a map on the screen. indicate. Then, a vehicle position mark indicating the vehicle position is superimposed and displayed at a predetermined location on the screen, so that it can be seen at a glance where the vehicle is currently traveling.

  Various map display functions are provided. For example, in addition to the normal display that displays the map in the same way as the road map, a bird's-eye view display that displays the map in a state of looking down from behind the vehicle position to give a sense of perspective, or a three-dimensional view of a building, etc. There are functions such as 3D display (3D display) for displaying a simple 3D image on a bird's eye view map, and a city map display for displaying details of road shape, house frame shape, and the like.

  In this type of navigation device, it is essential to measure the current position of the vehicle. For this reason, a measurement method (self-contained navigation) that measures the relative position of the vehicle using a distance sensor and an angle sensor mounted on the vehicle, and a vehicle that receives radio waves transmitted from a plurality of GPS satellites and performs n-dimensional positioning processing. A measurement method (satellite navigation) for measuring the absolute position of the sensor has been put into practical use.

  Although vehicle position measurement by self-contained navigation can measure the vehicle position at a relatively low cost, there is a problem that position measurement cannot be performed with high accuracy, and correction processing such as map matching processing is required. That is, in self-contained navigation, errors accumulate as the vehicle travels, and the vehicle position deviates from the road. Therefore, the vehicle position is compared with the road data by map matching processing and corrected on the road.

  Specifically, map matching processing deviates from road links (points where multiple roads intersect such as intersections and branch points are called nodes, and straight lines corresponding to roads and lanes connecting the nodes are called links). A process of drawing the vehicle position that has already been drawn onto the road link is performed. The map data includes position information of latitude / longitude for each existing node, and the position of the road link connecting the nodes is thereby determined. The vehicle position is corrected on the road link by collating the position of the road link with the vehicle position.

  FIG. 5 is a diagram showing a general road link defined by conventional map data. As shown in FIG. 5, a road with a median is defined as a separate road on each of the upper and lower lines, and a one-way road link RL2 is provided on each one way. On the other hand, a road without a median is defined as one road that can be bidirectionally passed for the purpose of reducing the size of map data, and one road link RL1 is provided on both roads. At the transition between a road with a median strip and a road without a median strip, two road links RL3 connect the road link of one bidirectional road and the road link of two one-way roads. Yes.

  However, if a road without a median is defined by a single road link, the vehicle position mark VM is displayed in the approximate center of the vertical line in the mode of displaying the road shape in detail, such as a city map display. As a result, there was a problem that the driver felt uncomfortable.

  If a road with a median strip is defined as two road links and a road without a median strip is defined as a single road link, the road link must be bifurcated at the transition. Therefore, the direction of the vehicle position mark is deviated with respect to the angle of the road link, and there is a problem that the vehicle position mark is displayed in a state like a so-called “crab run”. In addition, since the difference in shape between the road link and the actual road becomes large, there is a problem that matching cannot be performed or mismatch occurs.

On the other hand, assuming the number of virtual links according to the road width or the number of lanes of the road, map matching processing is performed for the virtual links to obtain the optimum link, and the vehicle position is set on the road according to the virtual link. There is a technique to correct (see, for example, Patent Document 1). There is also a technique in which the road width is changed on a taper when road links having different road widths are connected (see, for example, FIG. 5 of Patent Document 2).
JP 2004-226341 A Japanese Patent Laid-Open No. 6-83937

  However, the above-mentioned patent document 2 only mentions how to display the road shape, and does not mention map matching using a road link. Moreover, in the said patent document 1, it does not mention the road link in the part of the transition of the road with a median strip and the road without.

  The present invention has been made in order to solve the above-described problems. When the vehicle is traveling on a road without a median strip, the vehicle position mark is almost at the center of the vertical line in the city map display mode or the like. In addition to eliminating the discomfort displayed on the road, it is possible to suppress so-called crab driving and map matching mistakes when driving on the transition between a road with a median and a road without a median. .

In order to solve the above-described problems, in the present invention, on the basis of the road width information, the upper and lower lines of the first road without the median strip enter the lane width along the first road link. The first road of the second road link corresponding to the second road having the center separation zone and the end of the second road side of the first virtual link is obtained while obtaining the first virtual link extending A second virtual link that connects each of the first and second road links without any crossing, and a first virtual link instead of the first road link and a branch connection between the first and second road links Instead of the third road link to be used, the second virtual link is used, and the second road link is used as it is , and the map matching process for correcting and displaying the vehicle position on each link is performed.

According to the present invention configured as described above, when traveling the first road no median strip, for each their respective first road of the upper and lower lines, to enter the lane width Using the first virtual link set to extend along the first road link, map matching processing for correcting and displaying the vehicle position on the link is performed. As a result, the vehicle position mark drawn to the first virtual link is not displayed near the center of the vertical line in the width direction , and is corrected and displayed at a position in the lane along the actual travel locus. . Therefore, even in the mode of displaying the road shape in detail such as a city map display, it is possible to eliminate the inconvenience of giving the driver a sense of incongruity.

In addition, when the vehicle is traveling along the transition between the first road without the median strip and the second road with the median strip , the end on the second road side of the first virtual link Using the second virtual link set to connect the end of the second road link (two one-way streets) to the end of the first road without crossing the vehicle, Map matching processing for correcting and displaying the position on the link is performed. Here, the positional deviation in the width direction between the end portion on the second road side of the first virtual link and the end portion on the first road side of the second road link of the one-way road is The displacement in the width direction between the first road link and the second road link is sufficiently small . For this reason, the deviation of the direction of the vehicle position mark with respect to the angle of the second virtual link connecting between them is reduced, and the shape difference between the second virtual link and the actual road is also reduced. As a result, it is possible to suppress the occurrence of so-called crab running and map matching mistakes.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing virtual links set by the navigation device of the present embodiment. Moreover, FIG. 2 is a figure which shows the example of whole structure of the navigation apparatus by this embodiment. First, the overall configuration of the navigation device will be described.

  In FIG. 2, reference numeral 11 denotes a map information storage unit such as a DVD (Digital Versatile Disk), which stores various map data necessary for map display, route search, and the like. As a recording medium for storing the map data, other recording media such as a CD (Compact Disc), a hard disk, and a semiconductor memory may be used in addition to the DVD.

In the map data of this embodiment, the first road on the upper and lower lines without the center divider is defined by one common first road link , and the second road on the upper and lower lines with the center divider is moved up and down. It is defined by a pair of independent second road links. In other words, the second road with the median is defined as a separate road for each of the upper and lower lines, and one second road link is set for each one way. On the other hand, the first road without the median is defined as one road that can be bidirectionally passed, and one first road link is set on both roads. One road link of the bidirectionally accessible road is set near the center in the width direction of the vertical line.

  The map data recorded on the DVD 11 includes a road layer composed of data necessary for various processes such as map matching, route search, and route guidance. This road layer includes a connection node table storing detailed data of all nodes and a link record storing detailed data of links specified by two adjacent nodes. FIG. 3 is a diagram illustrating a configuration example of the connection node table and the link record. FIG. 3A illustrates a configuration of the connection node table, and FIG. 3B illustrates a configuration of the link record.

  In FIG. 3A, the normalized longitude / latitude of the node indicates the relative position of the node in the longitude / latitude direction. The node attribute flag indicates various node attributes such as whether or not the node is an intersection node. The number of connected nodes indicates the number of nodes constituting the other end of each link when there is a link having that node as one end of the link.

  The number of traffic regulations indicates the number of traffic regulations when there is traffic regulation such as right turn prohibition or U-turn prohibition on the link connected to the node. The connection node record indicates the link number of each link having the node at one end as many as the number of links. The traffic regulation record indicates the specific contents of the traffic regulation corresponding to the number of traffic regulations described above, if any.

  In FIG. 3B, the link ID indicates a code attached to each link in order to specify a road. Node numbers 1 and 2 indicate numbers that specify two nodes located at both ends of the link. The link distance indicates the actual distance of the actual road corresponding to the link. The cost is a numerical value indicating the ease of travel of the link, and is a numerical value indicating the appropriate degree as a guide route. This cost is set in consideration of, for example, the length and width of the road, the road type (whether it is a general road or a highway), legal speed, right and left turns, traffic restrictions, congestion, and the like. The road type flag indicates a type indicating whether the actual road corresponding to the link is an expressway or a general road.

  The road attribute flag / lane width information indicates various attributes related to the link and the actual road width corresponding to the link. The road width regarding the road link of the one-way road with the median strip indicates the one-way road width. On the other hand, the road width regarding the road link of the bidirectionally accessible road without the median strip indicates the road width of both roads. FIG. 4 is a diagram illustrating a configuration example of the above-described lane width information. As shown in FIG. 4, the lane width information includes information indicating the road width and information indicating whether the road width is a total road width including the upper and lower lines or a one-way road width. It is.

  The route number indicates the number assigned to the actual road corresponding to the link. The number of lanes indicates the actual number of lanes on the road corresponding to the link. The number of lanes related to a one-way road link with a median strip indicates the number of one-way lanes. On the other hand, the number of lanes related to a road link on a two-way road that does not have a median strip indicates the number of lanes including both roads.

  Returning to FIG. 2, reference numeral 12 denotes a display device, which displays a map image, a vehicle position mark, a guidance route, and the like corresponding to the current position of the vehicle. A vehicle position detection unit 13 includes a self-contained navigation sensor, a GPS receiver, a position calculation CPU, and the like. The self-contained navigation sensor includes a vehicle speed sensor (distance sensor) that outputs a single pulse for each predetermined travel distance to detect the travel distance of the vehicle, and an angular velocity sensor such as a vibration gyro that detects the rotation angle (movement direction) of the vehicle. (Relative orientation sensor). The self-contained navigation sensor detects the relative position and direction of the vehicle using these vehicle speed sensor and angular velocity sensor.

  The position calculation CPU calculates the absolute own vehicle position (estimated vehicle position) and vehicle direction based on the relative position and direction data of the own vehicle output from the self-contained navigation sensor. The GPS receiver receives radio waves transmitted from a plurality of GPS satellites by a GPS antenna and performs a three-dimensional positioning process or a two-dimensional positioning process to calculate the absolute position and direction of the vehicle (the vehicle direction is The calculation is based on the current vehicle position and the current vehicle position one sampling time ΔT before).

  14 and an operation unit such as a remote controller, and the user sets various information (for example, a route guidance destination) to the navigation device, or performs various operations (for example, menu selection operation, enlargement / reduction operation, manual operation). There are various controls (buttons, joysticks, etc.) for performing map scrolling, numerical input, etc. A navigation control unit 15 performs map image generation processing around the vehicle using map data, map matching processing, route search processing, vehicle position mark and guidance route image generation processing, and the like.

  In the navigation control unit 15, reference numeral 21 denotes a read control unit that controls reading of map data from the DVD 11. Reference numeral 22 denotes a map information memory (corresponding to the map information storage unit of the present invention), which temporarily stores map data read from the DVD 11 under the control of the read control unit 21. Reference numeral 23 denotes a remote control unit which receives a signal corresponding to the operation of the remote control 14 and instructs each unit in the navigation control unit 15.

Reference numeral 24 denotes a map matching unit, which is the map data read into the map information memory 22, the vehicle position and vehicle direction data measured by the GPS position detector 13 and estimated by a self-contained navigation sensor. Using the vehicle position and vehicle orientation data, the travel position of the host vehicle is corrected on the road link for each predetermined travel distance (for example, 10 m). In the present embodiment, as will be described later, the first virtual link and the second virtual link are set, and the host vehicle is used by using the first virtual link , the second virtual link , and the second road link. A map matching process for correcting and displaying the position on each link is performed.

  Reference numeral 25 denotes a map image drawing unit, which reads out map data in a range wider than the screen display range around the current location from the map information memory 22 based on the vehicle position data after the map matching processing is performed by the map matching unit 24. A map image of dot image is generated based on the data. A guide route drawing unit 26 generates a guide route image of a dot image based on guide route data from the departure point to the destination obtained by the guide route search process.

  A video RAM 27 temporarily stores the map image generated by the map image drawing unit 25 and the guide route image generated by the guide route drawing unit 26. The map image drawing unit 25 rewrites the stored contents of the video RAM 27 as needed according to the running of the vehicle so that the display range of the display screen does not exceed the image range of the video RAM 27. In addition, the guidance route drawing unit 26 generates a guidance route image included in the display range stored in the video RAM 27 at that time according to the traveling of the vehicle, and rewrites the stored contents of the video RAM 27 as needed.

  An image cutout control unit 28 cuts out a map image and a guide route image for one screen from the video RAM 27 so that the current position of the vehicle is located at the center or the lower center of the display screen. The cutout position is instructed from the map image drawing unit 25. A vehicle position mark generator 29 generates a vehicle position mark image for display at the center or lower center of the display screen.

  Reference numeral 30 denotes a guidance route search unit, which searches for a guidance route from the departure point (for example, the current vehicle position) to the destination based on the map data stored in the map information memory 22. Reference numeral 31 denotes a guide route storage unit that stores a guide route from the departure place to the destination. A combining unit 32 combines the map image, the guide route image, and the vehicle position mark image read from the video RAM 27 and the vehicle position mark generating unit 29, outputs them to the display device 12, and displays the images.

Next, the virtual road link generation process performed by the map matching unit 24 will be described with reference to FIG. The map matching unit 24 first, for each of the upper and lower lines, with respect to a bidirectionally accessible road without a median strip, based on the road width information included in the map data stored in the map information memory 22 . determining a first virtual link extending along the input Ri first road link to the lane width.

For example, as shown in FIG. 1, the map matching unit 24 obtains the positions of the center line of the up line and the center line of the down line from the road width of the bidirectionally accessible road, and the first virtual link VL1 is set at this position. Set. For example, the average value of the road width (= (12-6)) with respect to the road link of the bidirectionally accessible road in which the total road width of the upper and lower lines is defined as 6 m to 12 m in the lane width information shown in FIG. / 2 + 6 = 9m), the one-way road width is determined to be 4.5m, and the first virtual link VL1 is set one by one at a position that is half the distance (2.25m) away from the center of the vertical line on both sides. . Then, the first road link RL1 that originally exists as map data is replaced with the two first virtual links VL1.

Next, the map matching unit 24 determines the two first virtual links obtained as described above with respect to the transition between the one-way road having the central separation zone and the bidirectional passage having no central separation zone. Two of VL1 connecting the end of the second road side and the end of the first road side of the two second road links RL2 representing one-way roads without crossing each other The second virtual link VL2 is obtained. Then, the third road link RL3 that is branched and connected between the end portion of the one road link RL1 and the end portions of the two second road links RL2 that originally exist as map data is described above. The two second virtual links VL2 obtained as described above are replaced. As described above, the map matching unit 24 of the present embodiment includes the functions of the first virtual link calculation unit and the second virtual link calculation unit of the present invention.

When the vehicle is traveling on the first road without the median strip, the map matching unit 24 enters the lane width and follows the first road link for each of the upper and lower lines of the first road. Using the first virtual link VL1 set so as to extend, a map matching process for correcting the vehicle position on the link is performed. As a result, the vehicle position mark VM attracted to the first virtual link VL1 is not displayed near the center in the width direction of the vertical line as in the past, and is corrected to a position in the lane along the actual travel locus. It will be displayed. Therefore, even in the mode of displaying the road shape in detail such as a city map display, it is possible to eliminate the inconvenience of giving the driver a sense of incongruity.

Further, when the vehicle is traveling on a transition between the first road without the median strip and the second road with the median strip , the map matching unit 24 has two first virtual links. a second road-side end of the VL1, to connect each without intersecting between the first road-side end of the second road to two of the second road link corresponding RL2 Using the second virtual link VL2 set to, map matching processing for correcting and displaying the vehicle position on the link is performed. Here, the width direction position between the second and the end of the road side, whereas the first road-side end of the second road link RL2-way path of the first virtual link VL1 The shift is sufficiently smaller than the shift in the position in the width direction between the first road link and the second road link . For this reason, the deviation of the direction of the vehicle position mark with respect to the angle of the second virtual link connecting between them is reduced, and the shape difference between the second virtual link and the actual road is also reduced. As a result, it is possible to suppress the occurrence of so-called crab running and map matching mistakes.

  In the above-described embodiment, the example in which the center lines of the vertical lines obtained from the road width are set to the first virtual link VL1 has been described. However, the center lines are not necessarily the center line. In short, it is only necessary to set one first virtual link VL1 within the road width of the up line and one first virtual link VL1 within the road width of the down line. However, a position closer to the center line is more preferable than a position extremely away from the center line.

  Moreover, although the said embodiment demonstrated the example which sets one 1st virtual link to each of an up-down line according to a road width, this invention is not limited to this. For example, you may make it set the 1st virtual link by the number according to the number of lanes to each of an up-and-down line.

  Further, the virtual road link generation process described in the above embodiment may or may not always be performed. For example, the above-described virtual road link generation process may be performed only when the stereoscopic display mode, the city map display mode, or the like is set and the road shape is displayed in detail.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. In other words, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

  INDUSTRIAL APPLICABILITY The present invention is useful for a navigation apparatus having a map matching function that corrects a vehicle position on a road link by comparing the position of the road link with the vehicle position.

It is a figure which shows the virtual link set by the navigation apparatus of this embodiment. It is a figure which shows the structural example of the navigation apparatus by this embodiment. It is a figure which shows the structural example of the connection node table and link record by this embodiment. It is a figure which shows the structural example of the lane width information by this embodiment. It is a figure which shows the conventional road link.

Explanation of symbols

22 Map information memory 24 Map matching unit 29 Vehicle position mark generation unit

Claims (1)

Upper and lower common first road link data corresponding to the first road on the upper and lower lines without the median strip, a pair of upper and lower independent second roads corresponding to the second road on the upper and lower lines with the median strip A map information storage unit that stores link data, data of a third road link that branches and connects between the first and second road links, and map data that includes road width information related to the first road ; ,
Based on the road width information included in the map data, for each of the first road in the vertical line, determining a first virtual link extending along the enters the lane width first road link A first virtual link calculation unit;
Second virtual links that connect the second road-side end portion of the first virtual link and the first road-side end portion of the second road link without crossing, respectively. A second virtual link calculation unit for obtaining a link;
The first virtual link is used instead of the first road link, the second virtual link is used instead of the third road link, and the second road link is used as it is. And a map matching unit for performing a map matching process for correcting and displaying the information on each link .