WO2011132498A1 - Current position display device, and current position display method - Google Patents

Abstract

A current position display device provided with a current position detection means, a map database, a map matching means, a display control means, and a display means, is further provided with an inclination determination means that detects changes in angular velocity. The current position detection means detects a virtual current position; the inclination determination means calculates the inclination angle on the basis of the angular velocity detected by the inclination determination means, and calculates the reliability of links that serves as candidates in the vicinity of the virtual current position in reference to the map database on the basis of the inclination angle; the map matching means carries out a matching process on the more reliable links; and the display control means displays the current position obtained by the matching process along with a map image on the display means.

Description

Current position display device and current position display method

The present invention relates to a current position display device and a current position display method, and in particular, detects traveling on a main line such as an expressway, or an approach road or a branch road from a main road to a general road, and correctly displays it on a map. The present invention relates to a current position display device and a current position display method.

Conventionally, a navigation device receives a GPS signal from a GPS satellite, calculates a current position based on the information, and displays the calculated current position on a map displayed on a display screen provided in the navigation device. By doing so, it is possible to identify where the user is now.

Furthermore, the obtained current position data is compared with the road data stored in the map database, and if the current position is not on the road data, the current position is displayed on an appropriate road using various matching methods. Matching and displaying the current position along with the map on the display screen.

However, on general highways, etc., the main road of the highway and the branch road and approach road that are connected to the general road are provided almost in parallel, and the branch road and the approach road are slightly branched from the main road. It is provided at an angle. In such a case, it is difficult for the navigation device to determine whether the vehicle is traveling on the main road of an expressway or a general road, and an accurate matching process cannot be performed. In some cases, the current position is displayed incorrectly.

The following Patent Document 1 (Japanese Patent Laid-Open No. 9-304095) discloses an invention relating to an “in-vehicle navigation device”. This in-vehicle navigation device can determine whether a vehicle equipped with a navigation device is on a highway based on a direction sensor, a vehicle speed sensor, a vehicle speed, a traveling direction change amount, a stop time, a continuous travel time, and the like. it can.

Japanese Patent Laid-Open No. 9-304095

By the way, when the navigation device is of a type that is fixedly installed in the vehicle, it is possible to accept input of signals such as a vehicle speed pulse signal and an inclination sensor wired from the vehicle. Therefore, in addition to the calculation of the current position based on the GPS signal, the calculation result of the current position can be corrected using the input signal, and a more accurate current position can be detected.

However, when the navigation device is of a type that is detachably installed in the vehicle (portable type), it is necessary to perform wiring work with a vehicle speed pulse signal, an inclination sensor, etc. wired from the vehicle every time the navigation device is mounted on the vehicle. Since this is a burden on the user, it is usually often used without such wiring. And if you can not receive the vehicle speed pulse signal wired from the car or the input signal from the tilt sensor etc., the branch road and the approach road that are the connecting road to the main road of the expressway and the general road are provided almost in parallel, In addition, when the branch road or approach road is provided at a slight branch angle with respect to the main line, the navigation device determines whether the vehicle is driving on the main road of an expressway or a general road. Since it cannot be determined, there arises a problem that the current position cannot be accurately displayed on the map.

Therefore, an object of the present invention is to provide a navigation device with a built-in gyroscope in which a main road of a highway and a branch road or approach road that is a connection path to a general road are provided substantially in parallel, and the branch road or approach road is provided. Provides a current position display device and current position display method that can accurately determine the current position using the output of the gyroscope and display it on the map even if it is provided at a slight branch angle with respect to the main line It is to be.

In order to solve the above problems, the current position display device of the present invention is
A current position detection means, a map database, a map matching means, a display control means, and a display means, and the map matching means detects a virtual current position detected by the current position detection means from the map database. In a current position display device that performs a matching process as an actual current position on a link that is a candidate for map matching that is specified, and the display control means displays the actual current position together with a map image on the display means,
The current position display device further includes an inclination determination unit that detects a change in angular velocity, the inclination determination unit calculates an inclination angle based on the detected angular velocity, and refers to the inclination angle and the map database. A reliability for a candidate link is calculated, and the map matching unit performs a matching process on a link with higher reliability based on the calculated reliability.

Moreover, in one aspect of the invention of the current position display device,
The map database stores information indicating a first detection point that is a point where the inclination determination unit should calculate an inclination angle, and the inclination determination unit has the virtual current position near the first detection point. A tilt angle is calculated at a certain time, and a first reliability for the candidate link is calculated based on the calculated tilt angle.

Moreover, in one aspect of the invention of the current position display device,
The map database stores information indicating a second detection point associated with the first detection point, and the inclination determination unit further inclines when the virtual current position is near the second detection point. An angle is calculated, and the first reliability is corrected based on the calculated inclination angle.

The present position display method of the present invention is
A current position display method in a current position display device comprising a current position detection means, a map database, a map matching means, a display control means, and a display means,
The current position display device further includes an inclination determination means for detecting a change in angular velocity,
(1) detecting a virtual current position by the current position detecting means;
(2) the inclination determination means calculating an inclination angle based on the detected angular velocity;
(3) calculating reliability for a link that is a candidate for map matching near the virtual current position with reference to the inclination angle and the map database;
(4) the map matching means performing a matching process on a link with higher reliability;
(5) the display control means displaying the matching-processed current position together with a map image on the display means;
It is characterized by providing.

The present position display device of the present invention has the following excellent effects.

That is, the current position display device of the present invention includes an inclination determination unit that detects a change in angular velocity, the inclination determination unit calculates an inclination angle based on the detected angular velocity, and refers to the inclination angle and the map database. Then, the reliability for the candidate link is calculated, and based on the calculated reliability, the map matching unit performs a matching process on a link with higher reliability. Thereby, by identifying the change in the inclination of the vehicle, the matching process can be performed with high accuracy, and the current position can be notified to the user more accurately.

In addition, according to one aspect of the present invention, the main line of the first detection point where the inclination determination unit should calculate the inclination angle, for example, a main road such as an expressway, and the connection path are provided substantially in parallel, and the connection path is in relation to the main line. A point that is provided with a slight branching angle is stored, the inclination angle is calculated when it reaches this point, and the reliability for the candidate link is calculated based on that, and the reliability is high Matches on the link. This makes it possible to perform matching processing with high reliability.

Moreover, according to one aspect of the present invention, the tilt determination unit stores information indicating the first point where the tilt angle should be calculated and the second detection point associated therewith, and the tilt determination unit is configured to store the virtual current position. Is calculated in the vicinity of the first detection point and the second detection point, and the reliability is corrected by the inclination angle calculated at the second detection point with respect to the reliability of the first detection point. Thereby, since the inclination angle is calculated at two locations, map matching can be performed with higher accuracy than when the inclination angle is calculated at one location and the reliability is obtained.

In addition, according to the current position display method of the present invention, it is possible to display the current position with high accuracy as in the above-described current position display device.

It is an internal block diagram of the navigation apparatus which concerns on a present Example. It is explanatory drawing of the road data memorize | stored in the map database of a present Example. It is a flowchart which shows operation | movement of the route guidance in the navigation apparatus of a present Example, and the present position display method. It is a schematic explanatory drawing of the method of performing map matching based on the detected inclination in the navigation apparatus of a present Example.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS. 1 to 4 together with embodiments. However, in the following embodiments, a current position display device for embodying the technical idea of the present invention and a navigation device will be described as an example of a current position display method, and the present invention will be described. However, the present invention is equally applicable to other current position display devices and current position display methods without departing from the technical idea shown in the claims.

FIG. 1 shows an internal block diagram of the navigation apparatus 10 according to the present embodiment. As shown in FIG. 1, the navigation apparatus 10 includes a control unit 100, a current position detection unit 110, a display input unit 120, a display control unit 130, a route search unit 140, a storage unit 150, a route guide unit 160, and a tilt determination. Means 170, map matching means 180, and map database 190 are provided.

The control unit 100 includes a CPU 101, a RAM 102, and a ROM 103. The CPU 101 executes a control program stored in the RAM 102 and / or the ROM 103, thereby controlling and supervising operations of each unit described below.

The current position detection unit 110 includes a GPS reception unit 111, which generates radio waves (satellite signals) including time information received from a plurality of GPS satellites orbiting the earth at predetermined time intervals. Based on this, position information (GPS positioning position) of the vehicle is calculated.

The current position detection unit 110 also includes an acceleration sensor (not shown) and an autonomous navigation sensor such as the gyroscope 112, so that the GPS reception unit 111 receives the signal based on the output from the acceleration sensor and the gyroscope 112. The position information calculated based on the satellite signal can also be corrected. Also, by providing an autonomous navigation sensor, even in places where GPS satellite signals cannot be received, such as tunnels, underground shopping streets, underground parking lots, parking lots in buildings, or high-rise buildings, where the location is affected by multipath due to the reflection of GPS satellite signals The position of the navigation device 10 (vehicle) can be calculated from the output from the acceleration sensor or the gyroscope 112.

The display input unit 120 includes a display unit 121 and an input unit 122. The display means 121 is a liquid crystal display unit, and the input means 122 is a touch panel attached on the liquid crystal screen of the liquid crystal display unit. The display unit 121 displays a map image displayed on the navigation device 10 of the present embodiment, a display image showing a guidance route, and the like, and the input unit 122 is operated by the user, and route search conditions such as a departure position and a destination position are displayed. Used to input

The display control unit 130 processes a map image extracted from the map database 190 along a guide route (described later) stored in the storage unit 150 and displays the map image on the display unit 121, or a display indicating the guide route on the map image. The images are superimposed and displayed on the display means 121.

The route search means 140 stores in the map database 190 the optimum route (guide route) from the current position detected by the departure position or current position detection means 110 to the target position set by the user using the display input means 120. The map is searched with reference to the map information. The link from the node of the road corresponding to the starting position or the current position to the node corresponding to the target position is searched by a technique such as the Dijkstra method, and the link length (link Cost) and required time are accumulated, and a route having the shortest total link length (travel distance) or total required time is obtained as a guide route.

The storage unit 150 stores the departure position and the target position input by the user using the display input unit 120 and the guide route searched by the route search unit 140 as guide route data. Furthermore, the inclination angle of the navigation device 10 (the inclination angle of the vehicle) calculated by the inclination determination means 170 based on the angular velocity output from the gyroscope 112 is stored.

In this embodiment, it is assumed that the navigation device 10 is installed in parallel to the vehicle, and in the following description, the inclination angle calculated by the inclination determination means 170 will be described as the inclination angle of the vehicle.

The route guidance unit 160 extracts the map information around the current position from the map database 190 to the display control unit 130 based on the guidance route stored in the storage unit 150 and the current position detected by the current position detection unit 110. The display control means 130 superimposes the display image showing the guidance route on the extracted map image and displays it on the display means 121. In addition, when the navigation device 10 includes a speaker or the like, the route guidance unit 160 helps the user move along the guidance route by broadcasting voice guidance for route guidance. The voice guidance is preferably stored in the map database 190 or the like in association with the road data in the map database 190.

The inclination determination means 170 determines whether or not the current position is at a point (detection point) where the inclination associated with the node of the road data is to be detected, and when it is determined that the current position is at the inclination detection point. Then, by integrating the angular velocity data output from the gyroscope 112 for a predetermined time, the inclination angle of the vehicle is calculated and stored in the storage unit 150.

Further, the inclination determination unit 170 compares the calculated inclination angle with the uplink / downlink attribute associated with the road data link, thereby trusting the link as a map matching candidate specified by the map matching unit 180 described later. Calculate the degree. Here, the map matching candidate link is, for example, a main road of a highway and a branch road or approach road that is a connection path to a general road are provided substantially in parallel, and the branch road or approach road is the main road. On the other hand, when it is provided at a slight branch angle, it means a link corresponding to the main line and a branch path and / or an approach path (link L3 and link L4 branching from node N3 shown in FIG. 2). The reliability is an evaluation value that serves as an index indicating which of the links that are candidates for map matching is likely to be running.

Specifically, as shown in FIG. 4D, a data table in which the inclination angle and the change value of the reliability are associated with each other is provided in the storage unit 150 and the map matching is performed when the inclination angle is calculated. The reliability for the candidate link is changed by the reliability change value corresponding to the calculated inclination angle. For example, when a link with “uplink” added as a link attribute and a link with “no attribute” are candidates for map matching, when an inclination angle of plus 3 degrees is calculated, FIG. 10% is subtracted from the reliability of the “no attribute” link. That is, if the evaluation value of the link with “uplink” and the link of “no attribute” is set to 100% in advance, the evaluation value of the “no attribute” link is subtracted by 10% to 90%. And As a result, a map matching process by the map matching unit 180 described later is performed on the link to which “uplink” having high reliability is added.

Further, the inclination determination unit 170 determines whether or not it is necessary to detect inclination again after detecting inclination once, calculates the inclination angle again when a predetermined condition is satisfied, and becomes a link that is a candidate for map matching. The reliability for is calculated. Note that the predetermined condition is when the difference in reliability between links (link L3 and link L4 shown in FIG. 2) that are candidates for map matching at the time of the first slope calculation is equal to or smaller than a predetermined value (in which link This is the case where the map matching or the conclusion cannot be settled) or the point (second detection point) where the inclination should be detected again in the node attribute of the road data in the map database 190.

And, when the inclination detection is performed again, the reliability for the link that is a candidate for map matching is calculated in the same manner.

In addition, when the angular velocity data output from the gyroscope 112 when the vehicle passes through the first detection section is the positive angular velocity data, the angular velocity data output when passing through the second detection section is negative angular velocity data. It becomes. Therefore, when the angular velocity data is output between the second inspection areas, the inclination angle is obtained after reversing the sign of the output angular velocity data.

The map matching means 180 uses the current position calculated by the current position detection means 110 as a virtual current position, and corresponds to a link that is a candidate for map matching in the vicinity of the virtual current position, in particular, in this embodiment, corresponds to the main line. A link and a link corresponding to a branch road or an approach road that branches off from the main line at a slight inclination angle are identified (links L3 and L4 branching from the node N3 shown in FIG. 2). Next, the map matching means 180 draws a perpendicular line from the virtual current position to those links, sets the intersection of the perpendicular line and the link as the actual current position candidate, and sets these map matching candidates at the distance from the virtual current position to the current position candidate. The position on the link with the highest reliability is set as the actual current position, taking into account the reliability (calculated by the inclination determination means 170) for each link. In other words, in this embodiment, the actual current position is specified by combining the distance from the virtual current position to the current position candidate and the reliability of the link that is a map matching candidate calculated by the inclination determination unit 170. Will be able to.

The map database 190 holds map information composed of road data, building data, background data, and text data.

The road data is composed of node data whose nodes are nodes such as inflection points and branch points of roads, and link data whose links are links between the nodes. The node data includes node attributes such as node number, node position coordinates (latitude / longitude), intersection information, intersection name, and inclination detection point (first detection point, second detection point in FIG. 2). In addition, it includes data on the number of connection links and connection link numbers.

In addition, the 2nd detection point in FIG. 2 is matched and memorize | stored as a detection point corresponding to a 1st detection point.

The link data includes the node numbers that are the starting and ending points of the link, the first road type for distinguishing expressways, ordinary roads, streets, etc., and the first road for distinguishing the main line and connecting road of each road. 2 Road type, further including up / down attribute indicating road inclination, distance and / or required time, road name such as National Route ○, and data of traveling direction. In the up / down attribute, in addition to the above information, information on the actual gradient of the road may be stored. In addition to the above, link data includes data such as bridges, tunnels, railroad crossings, and tollgates as link attributes.

The building data is configured to include position coordinates (latitude / longitude) consisting of at least three points of the building, types of buildings such as stations, buildings, and private houses, and display color data. Further, the background data is configured to include position coordinates (latitude / longitude) composed of at least three points serving as background image data such as a coastline, a lake, a river shape, and a forest, and display color data.

The text data is composed of data of each place name, river name, etc. (name) and its coordinates (latitude / longitude).

In addition, although said navigation apparatus 10 demonstrated as a stand-alone type | mold which incorporated the map database 190 in the navigation apparatus 10, this invention is not limited to this. For example, the navigation device 10 is provided with communication means (not shown), connected to an information providing server (not shown) outside the navigation device 10 for communication, and the above-described map database provided in the information providing server You may make it acquire the map information linked | related with the guidance route.

In that case, the navigation device 10 designates the departure point or the current point and the destination point, transmits this to the information providing server as a route search condition, and requests the route search. The information providing server is provided with route search means, performs a route search using the departure point or the current point and the destination point received from the navigation device 10 as route search conditions, and transmits the search result to the navigation device 10.

Next, the road data stored in the map database 190 of this embodiment will be described in detail with reference to FIG. In addition, FIG. 2 is explanatory drawing of the road data memorize | stored in the map database of a present Example.

As shown in FIG. 2, it is assumed that an interchange 211 is provided on the highway 210, and there is a road where the connecting road 212 branches and connects to the general road 213 (FIG. 2A). In this case, the road data includes a node N1 that is the starting point of the highway 210, a node N2 that is an intermediate point of the highway 210, and a node N3 that is a branch point between the highway 210 and the connecting road 212 to the general road 213 in the interchange 211. A node N4 that is the end point of the expressway 210, a node N5 that is a connection point between the connecting road 212 and the ordinary road 213, a node N6 that is the end point of the ordinary road 213, links L1 to L3 associated with the expressway 210, a highway The link L4 is associated with the connection path 212 from the road to the general road, and the link L5 is associated with the general road 213 connected to the connection path 212.

Furthermore, “downlink” is added as an uplink / downlink attribute to the link L4 corresponding to the connection path 212 (FIG. 2B). This indicates that the vehicle is descending at a certain slope after branching from the expressway 210 along the connecting road 212 and is connected to the general road 213. The up / down attribute may include information on the actual slope of the road.

Further, the first detection point (N3) and the second detection point (N5) indicate that the node N3 and the node N5 at both ends of the link L4 having the uplink / downlink attributes are points where the inclination should be detected. ) Information is associated.

Next, the current position display method in the navigation device 10 according to the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the operation of the route guidance and current position display method in the navigation device 10 of this embodiment. FIG. 4 is a schematic explanatory diagram showing a method of performing map matching based on the detected inclination in the navigation device 10 of the present embodiment.

First, in step S301, the start position and the target position are input and set by the user via the input means 122 constituting the display input means 120. The input starting position and target position are stored in the storage means 150.

Next, in step S302, the route search means 140 performs a route search by referring to the map database 190 based on the departure position and the target position stored in the storage means 150. In the route search, a link from the road node corresponding to the starting position or the current position to the node corresponding to the target position is searched by a technique such as the Dijkstra method, and the link length (link cost) and the required time are accumulated. A route having the shortest total link length (travel distance) or total required time is set as a guide route, and road nodes and links belonging to the route are stored in the storage unit 150 as guide route data.

In the above description, when the user does not specify the departure point, a route search from the current position detected by the current position detection unit 110 to the target position is performed.

In step S303, the route guidance unit 160 starts route guidance, and in step S304, the current position detection unit 110 calculates the current position and sets this as the virtual current position. In step S305, the inclination determination unit 170 determines whether or not the virtual current position is at a point where inclination should be detected by referring to the attribute of the node data stored in the road data of the map database 190. Specifically, when the car is traveling on the highway 210 and approaches the interchange 211, the inclination determination unit 170 detects the inclination of the current position based on the information on the first detection point associated with the node N3. It is determined that it is located at a power point. In FIGS. 2 and 4, not the point where the inclination should be detected, but a section (first detection section) extending from the first detection point to a predetermined distance range, and the inclination is calculated within this section. In addition, the range of this 1st detection area can be changed and can also be set arbitrarily.

If it is determined that the current position is not at a point where the inclination is to be detected, the process proceeds to step S311. If the map matching unit 180 performs normal map matching and the route guidance is not completed, the process returns to step S304. .

If it is determined in step S305 that the current position is a point where inclination should be detected, the process proceeds to the subsequent step S306. At this time, the vehicle passes through the node N3 which is a branch point of the expressway 210 and the connection path 212 to the general road 213 in FIG. 4, and links L3 (main line) and L4 (connection) connected to the node N3. Corresponds to the state of trying to travel on either of the road).

In step S306, the inclination determination unit 170 obtains the vehicle inclination angle by integrating the angular velocity output by the gyroscope 112 for a predetermined time, and stores the vehicle inclination angle in the storage unit 150. The angular velocity integral calculation may be performed by the gyroscope 112 itself.

In step S307, the inclination determination unit 170 obtains the travel reliability for each of the links L3 and L4 connected to the node N3 based on the inclination angle obtained in the process of step S306. Specifically, the reliability is calculated by comparing the calculated inclination angle with the uplink / downlink attributes associated with the links L3 and L4. When the road gradient information is included in the up / down attribute associated with the link, the inclination determination unit 170 compares the inclination information with the calculated inclination angle, thereby obtaining each candidate link L3. , The reliability for L4 can also be calculated.

In subsequent step S308, the inclination determination means 170 determines whether or not to detect the inclination angle again. Specifically, when the difference in reliability for each candidate link obtained in step S307 is less than a predetermined value, it is determined that tilt angle detection is performed again. Alternatively, the inclination angle can be detected again with reference to the node attribute of the road data in the map database 190 when the second detection point is set.

For example, when it is detected at the node N3 that it is the first detection point, the inclination determination means 170 is associated with the second detection point, that is, the first detection point, at the nodes N4 and N5 that are the end points of the subsequent links. It is determined whether or not a second detection point is provided. If there is no second detection point, the process proceeds to step S311 and the map matching unit 180 is on a link with higher reliability among candidate links. Perform map matching processing.

If there is a second detection point, the process proceeds to step S309. It should be noted that in reality, the inclination should be detected in a section extending from a second detection point to a predetermined distance range in front of the second detection point, and is shown as a second detection section in FIG. The range of this 2nd detection area can be changed and can also be set arbitrarily.

In step S309, when it is assumed that the vehicle is traveling near the connection path 212 and the virtual current position reaches the second detection section, the inclination determination unit 170 integrates the angular velocity output from the gyroscope 112 for a predetermined time. Find the vehicle's tilt angle.

When the vehicle is traveling from the main line to the connecting road 212 at the interchange 211, the angular velocity data output from the gyroscope 112 when passing through the first detection section starting from the node N3 is set as a positive angular velocity. In this case, the angular velocity data output when passing through the second detection section reaching the node N5 is negative angular velocity data. Therefore, the inclination angle is obtained after reversing the sign of the angular velocity data output between the second inspection areas.

In subsequent step S310, the inclination determination means 170 corrects the travel reliability for each of the corresponding links L3 and L4 based on the newly measured inclination angle. The travel reliability correction may be performed only when the reliability obtained at the first detection point is low, or the reliability obtained at the second detection point is added to the reliability obtained at the first detection point. This may be done by adding degrees.

In step S311, the map matching unit 180 adds the reliability based on the inclination angle obtained by the above method to the distance from the virtual current position to the current position candidate, and determines the link with the higher overall reliability. The travel link is specified, the current position is map-matched to a predetermined position of the specified link, and the display control unit 130 displays a guide image together with the map image on the display unit 121.

In step S312, the route guidance unit 160 determines whether or not the route guidance should be terminated by determining whether or not the map-matched current position is the target position. If the destination position has been reached, the route guidance is terminated. If the target position has not been reached, the process proceeds to step S304.

The gyro built in the navigation device when the branch road or approach road, which is a connection road to the main road of the expressway and the general road, is provided with a slight branch angle by the above method. Using the output of the angular velocity of the scope, the inclination angle of the vehicle is detected, the reliability for the related link is calculated from the inclination angle, the higher reliability is identified as the traveling link, and the current position is placed on the link Map matching can improve the matching accuracy.

Furthermore, when the vehicle tilt angle is detected at the first detection point, the vehicle tilt angle is also detected at the second point associated with the first detection point, and the reliability obtained at the first detection point. Is corrected, a highly reliable one is specified as a traveling link, and the current position is map-matched on the link. This makes it possible to perform map matching with higher accuracy.

In the above embodiment, the navigation device is illustrated as the current position display device of the present invention, the start position and the target position are specified, and the route guidance is performed along the route obtained by performing the route search. However, the present invention is not limited to this. For example, the present invention can be adapted to the case where the current position detected by the current position detecting unit 110 is displayed on a corresponding map without performing route guidance.

In the present embodiment, the inclination determination unit 170 calculates the vehicle inclination angle based on the output of the gyroscope 112. However, the present invention is not limited to this. For example, the output of an acceleration sensor, an inclination sensor, or the like is output. As long as the tilt angle can be calculated by using the sensor, the output of these various sensors may be used.

DESCRIPTION OF SYMBOLS 10 Navigation apparatus 100 Control means 110 Current position detection means 112 Gyroscope 120 Display input means 130 Display control means 140 Route search means 150 Storage means 160 Route guidance means 170 Inclination determination means 180 Map matching means 190 Map database

Claims (4)

A current position detection means, a map database, a map matching means, a display control means, and a display means, and the map matching means detects a virtual current position detected by the current position detection means from the map database. In a current position display device that performs a matching process as an actual current position on a link that is a candidate for map matching that is specified, and the display control means displays the actual current position together with a map image on the display means,
The current position display device further includes an inclination determination unit that detects a change in angular velocity, the inclination determination unit calculates an inclination angle based on the detected angular velocity, and refers to the inclination angle and the map database. A current position display device characterized in that a reliability for a candidate link is calculated, and the map matching means performs a matching process on a link with higher reliability based on the calculated reliability. The map database stores information indicating a first detection point that is a point where the inclination determination unit should calculate an inclination angle, and the inclination determination unit has the virtual current position near the first detection point. 2. The current position display device according to claim 1, wherein an inclination angle is calculated at a certain time, and a first reliability for the candidate link is calculated based on the calculated inclination angle. The map database stores information indicating a second detection point associated with the first detection point, and the inclination determination unit further inclines when the virtual current position is near the second detection point. The current position display device according to claim 2, wherein an angle is calculated, and the first reliability is corrected based on the calculated inclination angle. A current position display method in a current position display device comprising a current position detection means, a map database, a map matching means, a display control means, and a display means,
The current position display device further includes an inclination determination means for detecting a change in angular velocity,
(1) detecting a virtual current position by the current position detecting means;
(2) the inclination determination means calculating an inclination angle based on the detected angular velocity;
(3) calculating reliability for a link that is a candidate for map matching near the virtual current position with reference to the inclination angle and the map database;
(4) the map matching means performing a matching process on a link with higher reliability;
(5) the display control means displaying the matching-processed current position together with a map image on the display means;
The present position display method characterized by comprising.

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