JPH08106597A - On-vehicle navigation device - Google Patents

Abstract

PURPOSE: To realize new route guidance to enable to arrive at a destination as making a roundabout way around a congestion at the time of being caught into the congestion while traveling as receiving the route guidance. CONSTITUTION: At the time of the route guidance, a map picture drawing part 18 draws a map picture centering around a vehicle position together with a guiding route and a vehicle position mark by using guiding route data between a starting place and the destination searched by a route searching part 14 on the basis of the vehicle position detected by a GPS receiver 2 and stored in a guiding route storage part 15 and the map data of a CD-ROM 1, and screen- displays it on a display device 4. On the other hand, a measuring part 16 measures the duration of a state that the vehicle speed is kept below 20km/h on the basis of the vehicle speed detected by the GPS receiver 2. A discriminating part 17 gives a re-searching command to the route searching part 14 when the measured duration exceeds 3 minutes, and the route searching part 14 having received the re-searching command re-searches the optimum route to make a roundabout way around the congestion and arrive at the destination by using the map data, and corrects the guiding route data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle navigation device, and more particularly, it automatically searches an optimum route connecting a starting point and a destination using map data and performs route guidance using the searched guidance route data. The present invention relates to a vehicle-mounted navigation device.

[0002]

2. Description of the Related Art A vehicle-mounted navigation device is a vehicle position for detecting a current position and a current direction of a vehicle such as a CD-ROM storing map data, a map data storage device such as an IC memory card, a display device, and a GPS receiver. CD-R with map data including the current position of the vehicle
The map image centering on the vehicle position is drawn based on the map data and displayed on the display screen, and the vehicle position mark (location cursor) is fixed to the center of the display screen to move the vehicle. According to the above, the map image is scroll-displayed, or the map image is fixed on the screen and the vehicle position mark is moved so that the user can know at a glance where the vehicle is currently traveling.

The map stored in the CD-ROM or the like is
Depending on the scale level such as 1/12500, 1/25000, 1/50000, 1/100000, etc., it is divided into an appropriate size of longitude width and latitude width, and roads etc. are represented by latitude and longitude (nodes) ) Is indicated by the coordinate set. The road is composed of two or more nodes connected to each other, and a part connecting the two nodes is called a link. The map data includes (1) map matching consisting of road list, node table, intersection constituent node list, intersection net list, etc., road layer for route search, (2) road, building, facility, park on the map screen, Background layer for displaying rivers, etc. (3) Administrative division names such as municipal names, road names, intersection names, characters such as building names,
It is composed of a character / symbol layer for displaying map symbols and the like.

Some on-vehicle navigation devices are equipped with a route guidance function that enables a driver to easily travel to a desired destination on the road without making a mistake.
According to this route guidance function, a horizontal search method is used to find the shortest route connecting a certain starting point to a certain destination using map data,
Simulation calculation such as the Dijkstra method is performed to automatically search, and it is stored as guide route data.
When the guide route is drawn thicker on the map image by changing the color from other roads and displayed on the screen, or when the vehicle approaches the intersection where the route on the guide route should be changed within a certain distance, Draw an arrow indicating the route at the intersection where the route should be changed,
By displaying on the screen, the user can easily understand the optimal route to the destination. Furthermore,
With the route re-search function, when the vehicle deviates from the guide route while receiving a route guide, the optimum route connecting the vehicle position at that time to the destination is automatically searched again and the guide route data is corrected. To do. As a result, even if the vehicle deviates from the guidance route on the side road, it is possible to receive route guidance toward the destination according to the newly searched guidance route.

[0005]

By the way, in the conventional route guidance function, when a vehicle is caught in a traffic jam while traveling toward a destination, if the vehicle is followed by the route guidance as it is, the vehicle will be annoyed in the traffic jam. Must also
There was a problem that it took a very long time to reach the destination. On the other hand, when there is a route re-search function, if you deviate from the guidance route to avoid congestion, a new guidance route that connects to the destination will be searched, so you will reach the destination while bypassing the congestion by subsequent route guidance. Sometimes you can, but
If it does not deviate in the proper direction from the original guide route, the route returning to the original guide route will be re-searched due to a dead end,
Sometimes there was no way around the traffic.

[0006] From the above, an object of the present invention is to provide a vehicle-mounted navigation device capable of performing a new route guidance that bypasses the traffic congestion and reaches the destination even if the vehicle is caught in a traffic congestion while receiving the route guidance. To provide.

[0007]

According to the present invention, there is provided a map data storage means for storing map data,
Vehicle position detecting means for detecting a vehicle position and a vehicle direction, route searching means for automatically searching for an optimum route connecting a departure place and a destination using map data, and storing it as guide route data in the guide route storing means, A vehicle-mounted device provided with a map image drawing means for drawing a map image around the vehicle position together with the vehicle position mark using the map data and displaying the image on the display means and a route guiding means for guiding the route using the guiding route data. In the navigation device, a vehicle speed detecting means for detecting the vehicle speed, a measuring means for measuring the duration of the state where the vehicle speed is below a certain level, and comparing the duration measured by the measuring means with a predetermined reference value, The route searching means determines whether or not the congestion occurs, and when the determining means determines that the congestion occurs during the route guidance, the route search means displays the map data. There was re-searching an optimal path connecting to the destination bypassing the congestion from the current position, is achieved by modifying the guide route data stored in the guide route storage means.

[0008]

According to the present invention, the duration of time when the vehicle speed is below a certain level is measured, and the measured duration is compared with a predetermined reference value to determine whether or not a traffic jam has occurred, and to guide the route. When it is determined that there is a traffic jam, the map data is used to re-search for an optimal route connecting the destination from the current position to bypass the traffic jam and correct the guidance route data.
As a result, even if you are caught in a traffic jam while traveling toward your destination due to route guidance, you can automatically switch from the current position to the optimum route that can bypass the traffic congestion and reach the destination. Therefore, the desired destination can be quickly reached.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device according to an embodiment of the present invention. In the figure, 1 is a CD-ROM that stores map data composed of road layers, background layers, character / symbol layers, etc. for different scales, and 2 is a G that detects the vehicle position, vehicle direction, and vehicle speed by satellite navigation.
It is a PS receiver. Reference numeral 3 denotes an operation unit having a cursor key for map scrolling, a destination input key and the like, and 4 a display device for displaying a map image together with a vehicle position mark, a guide route and the like.

Reference numeral 10 denotes a navigation controller having a microcomputer configuration, which draws a map image including the current position of the vehicle together with a vehicle position mark using the map data stored in the CD-ROM 1 and displays it on the screen of the display device 4. When the destination is entered, the shortest route connecting the current position, which is the starting point, to the destination desired by the user is automatically searched using the map data by the horizontal search method and stored as the guide route, and then on the map image. A guide route is drawn in a color different from that of other roads and displayed on the screen together with the vehicle position mark to guide the route. Further, the navigation controller 10 re-searches for the shortest route that can reach the destination by bypassing the traffic congestion when the vehicle is caught in the traffic congestion during route guidance, and corrects the navigation route data.

Of the navigation controller 10, 1
1 is a buffer memory for storing the map data read from the CD-ROM 1, 12 is a cursor position calculation unit for calculating the cursor position according to the operation of the cursor keys, and 13 is the cursor position when the destination input key is pressed. When the destination is set, the destination setting unit 14 which sets the destination reads the necessary map data from the CD-ROM 1 into the buffer memory 11 and connects the current position with the starting point as the starting point. The shortest route is the buffer memory 11
It is a route search unit that searches by the horizontal search method using the map data read out to. Reference numeral 15 denotes a guide route storage unit that stores, as guide route data, a node data string in which the node data forming the route searched by the route search unit 14 is arranged in the route order. As shown in FIG.
It includes latitude coordinate data and an intersection identification flag indicating whether or not the node is an intersection node.

The vehicle speed 16 detected by the GPS receiver 2 is less than a certain value (here, 20 km / h or less is an example).
The measuring unit 17, which measures the duration of the state where the state becomes, compares the duration measured by the measuring unit 16 with a predetermined reference value (here, 3 minutes as an example), and determines whether or not there is congestion. A determination unit that determines that a traffic jam is occurring when the duration measured by the measurement unit 16 exceeds the reference value, and determines to the route search unit 14 a guide route that can bypass the traffic congestion and reach the destination. Give a search command again.

A map image drawing unit 18 buffers map data including the vehicle position stored in the CD-ROM 1 based on the vehicle position and the vehicle direction detected by the GPS receiver 2 when the route is not guided. Read to memory 11,
Using the read map data, a map image with the vehicle position as the center and the north facing upward is drawn together with the vehicle position mark. When the route is guided, the route guidance storage unit 15 is further provided.
The guide route data in the drawing area of the map image is read out from among the above, and the guide route is overlaid on the map image and emphasized in a specific color different from that of a normal road and thickly drawn. A video RA 19 stores the image drawn by the map image drawing unit 18.
M and 20 are video conversion units that read out the image stored in the video RAM 19, convert it into a predetermined video signal, and output it to the display device 4.

Road Layer The road layer in the map data has the structure shown in FIG. The road list RDLT is made up of data such as road types, the total number of nodes that make up the road, the positions of the nodes that make up the road on the node table NDTB, and the width to the next node for each road. The intersection constituent node list CRLT is, for each intersection on the map, a set of positions on the node table NDTB of the other end node of the link (referred to as an intersection constituent node) which is connected to the intersection. The node table NDTB is a list of all nodes on the map. Position information (longitude, latitude) for each node, an intersection identification flag indicating whether or not the node is an intersection, and if the intersection is an intersection, the node configuration node list is displayed. It is composed of a pointer or the like that points to the position and points to the position of the road to which the node belongs on the road list if it is not an intersection.

The intersection netlist CRNL is constructed as shown in FIG. 4, and has a fixed data area FDA.
(1) Intersection sequential number (information for identifying the intersection) (2) Map leaf number of the map including the intersection node (3) Data unit code Above, intersection node ID (4) Number of intersection constituent nodes (5) Sequential number of each adjacent intersection (6) Distance to each adjacent intersection (7) It has road attributes (road type, width) to each adjacent intersection. Up to seven adjacent intersection data are stored in one intersection netlist. Further, the intersection netlist CRNL has a rewriting data area RDA so that it is possible to store the cumulative distance, the sequential number of the previous intersection (one less the order), and the search order at the time of route search. .

The route search unit 14 is a destination input operation by the user.
Once the destination is set based on the intersection netlist C
Depart using the distance between intersections stored in RNL as it is
The horizontal search method is used to find the shortest guidance route connecting the ground and destination.
Explore. After that, the route re-search command is received from the determination unit 17.
When the car is hit, the vehicle is selected from the guide route data already searched.
A certain distance L from the current position in front of both traveling directions₀Away
Closest intersection CP ₁And L₁(= L₀+ L) or more
Closest intersection CP₂Select two intersections with and.
Then, on the guidance route between the two selected intersections
To the intersection netlist CRNL corresponding to each existing intersection
On the other hand, along the guide route between the two selected intersections
The distance between adjacent intersections (see item No. 9 in Fig. 4) is the pole
And replace it with a larger distance. After that, the election
Of the two projected intersections, the one closer to the current position
CP₁Intersection CP far from₂Shortest route connecting to
Is searched by the horizontal search method, and the original guidance
Replace and correct part of the road. Note that L₀Here is a car
CP even if both run at 20km / h₁Re-explore before reaching
A value that is as small as possible with a distance that can be completed sufficiently, and 1 minute
L because it can complete the re-search₀= 350m L
Is the expected length of traffic jam, and here is 5 km as an example.
You.

5 to 7 are flowcharts showing the operation of the navigation controller 10, FIG. 8 is an explanatory view showing roads around the vehicle position, FIG. 9 is an explanatory view of a route search method by the horizontal search method, and FIG. 10 is a screen table. It is explanatory drawing of an example, and is demonstrated according to these figures below. When the route search power supply is turned on, the GPS receiver 2 periodically detects the vehicle position, the vehicle direction, and the vehicle speed by satellite navigation.
On the other hand, the navigation controller 10 inputs vehicle position data and vehicle azimuth data from the GPS receiver 2 (see FIG. 5).
101), the map image drawing unit 18 transfers the map data including the vehicle position from the CD-ROM 1 to the buffer memory 1
1 and using the read map data, a map image with the vehicle position as the center and the north facing upward is recorded on the video RA.
It is drawn on M19, and a vehicle position mark whose vehicle azimuth direction is directed to the center of the map image is drawn. Video RAM 19
The image drawn in is read by the video conversion unit 20,
After being converted into a predetermined video signal, it is output to the display device 4 and displayed on the screen (step 102).

After that, the navigation controller 1
In 0, it is checked whether or not the map scroll operation is performed by the cursor key (step 103). If NO, the process returns to step 101 to input new vehicle position data and vehicle azimuth data from the GPS receiver 2 to set a new vehicle position. The center map image is drawn together with the vehicle position mark and displayed on the screen. Thereafter, by repeating the same processing, the map scrolls while the vehicle position is fixed at the center on the screen as the vehicle travels.

After that, the user sets the current position as the starting point,
When you want to travel along the optimal route to your desired destination,
Use the cursor keys to scroll the map and search for the destination. At this time, when the cursor key operation is started, the cursor position calculation unit 12 initializes the current vehicle position detected by the GPS receiver 2 as the initial cursor position (steps 103 and 104), and then the cursor key The cursor position is continuously changed according to the operation (steps 106 and 107). Further, the map image drawing unit 18 reads the map data including the cursor position from the CD-ROM 1 into the buffer memory 11, and uses the read map data to display in the video RAM 19 the map image with the north at the cursor position as the center. Draw and draw a cursor mark at the center of the map image. Video RAM 19
The image of is read by the video converter 20, converted into a predetermined video signal, and output to the display device 4 (step 105). As a result, the map image on the screen is scrolled according to the operation of the cursor key and the cursor mark is displayed at the center.

When the destination input key is pressed when the cursor is at the destination (YES in step 108), the destination setting unit 13 sets the cursor position at that time as the destination, and the route search unit 14 sets the destination. The data is output (step 109). The route search unit 14 which has input the destination data sets the current position detected by the GPS receiver 2 as the departure place (step 110). Then, the map data of the range from the starting point to the destination is included in the CD-R.
The OM1 is read to the buffer memory 11, and the shortest route connecting the starting point to the destination is searched by the horizontal search method using the road layer in the read map data.

A concrete search method will be described with reference to FIG. Here, for simplification, it is assumed that the intersection netlist CRNL of any intersection includes the first to fourth adjacent intersections, and the lower adjacent in FIG. 9 is the first adjacent intersection and the right adjacent is It is assumed that the second adjacent intersection, the upper adjacent one is the third adjacent intersection, and the left adjacent one is the fourth adjacent intersection.

First, the route search unit 14 checks whether the departure place is an intersection (step 201 in FIG. 6). If the departure place is an intersection, the departure place intersection STP is set (step 202), and the processes after step 204 are performed. If not, the nearest intersection is set as the departure point intersection STP (step 203),
The processing after step 204 is performed. Departure intersection STP
If it is determined that the destination is an intersection (step 204), if it is an intersection, it is determined as the destination intersection DSP (step 205), and the processing from step 207 onward is performed. Is set as the destination intersection DSP (step 206), and step 20
Processing after 7 is performed.

Departure intersection STP and destination intersection DS
When P is determined, the route search unit 14 firstly determines the departure point intersection S
CD-R the intersection netlists CRNL of all intersections included in a circle centered on TP and having a radius slightly longer than the distance between the departure intersection STP and the destination intersection DSP
The buffer memory 11 is read from the map data of OM1.
(Step 207). Then, the search order i is set to 0 (step 208). Buffer memory 11
Intersection netlist C related to the i-th intersection stored in
It is checked with reference to the RNL whether or not an intersection adjacent to the i-th intersection remains (step 209). The 0th intersection is the starting point intersection STP. In step 209, the j-th intersection (j = 0, 1, ...
Excludes those that are said to be.

Since four adjacent intersections remain, the first adjacent intersection A ₁ from the starting intersection STP to the first adjacent intersection A _{1 in the} intersection netlist CRNL related to the starting intersection STP is left. The total distance D from the departure point intersection STP to the adjacent intersection A ₁ is calculated with reference to the distance d ₂ of (step 210). D is the cumulative distance from the starting point intersection STP to the i-th intersection d ₁
Then, it can be obtained by the following expression d ₁ + d ₂ → D. Initially, when i = 0, d ₁ = 0, so D =
It becomes d ₂ .

Next, referring to the rewriting data area RDA of the intersection netlist CRNL related to the intersection A ₁ stored in the buffer memory 11, whether the search order of the adjacent intersection A ₁ is (i + 1), in other words, ,already,
For the intersection A ₁ , it is checked whether the accumulated distances on different routes and the information specifying the previous intersection is registered (step 211). Since it is NO here, it is made to correspond to the adjacent intersection A _1. , in the intersection network list CRNL according to the intersection a _1, (a) the sequential number of the zero-order intersection STP currently focused, (b) total distance D from the departure point intersection STP to the adjacent intersection a ₁ ( = Ad ₁ ), is stored in the rewriting data area RDA, and (c) (i) as the search order of the adjacent intersection A ₁ is stored.
+1) = 1 is stored in the rewrite data area RDA (step 212).

Then, the process returns to step 209, where the departure
Intersection netlist CRNL for the difference point STP
An intersection that is adjacent to the 0th intersection you are looking at
Check if it still exists and repeat the same process if it remains
You. As a result, the intersection net list of the departure point intersection STP
Intersection A adjacent to₁~ A_FourBecause there are these
Is the primary intersection and the intersections related to these primary intersections
In each data rewriting area of the difference netlist CRNL
Is the total distance Ad₁~ Ad_FourAnd each adjacent intersection A ₁~ A
_FourFor identifying the previous intersection STP corresponding to
The serial number is registered.

When the processing is completed for all the adjacent intersections included in the intersection net list CRNL for the departure point intersection STP, the route searching unit 14 causes the departure point intersection ST to be processed.
It is judged whether there is a 0th intersection other than P (step 209 in FIG. 6, step 301 in FIG. 7), and since it does not exist, whether or not the destination intersection DSP is subsequently reached, in other words, the (i + 1) th intersection Destination crossing DSP in the intersection
Is included (step 302), and if not, i is incremented to 1 (step 30).
3). Then, the process proceeds to step 209 in FIG. 6, by focusing on one A ₁ among which is the first intersection, with reference to the intersection network list CRNL according to the intersection A ₁ stored in the buffer memory 11, the Except for the 0th-order intersection STP, it is determined whether or not an adjacent intersection remains.

Here, B₁₁, B₁₂, B₁₄There exists
So, first of all, the first adjacent intersection B ₁₁About the intersection
A₁Please refer to the intersection netlist CRNL related to
From departure point intersection STP to adjacent intersection B₁₁Up to
The distance D is calculated (step 210). Departure intersection S
The first intersection A that is currently focused on from TP₁Up to
Distance d₁At the intersection A in the buffer memory 11₁Exchange relating to
Ad to RDA of difference point netlist CRNL₁Remember as
It is done and the first intersection A₁From the adjacent intersection B₁₁
Distance to₂Is intersection A₁Intersection netlist
Since it is stored in CRNL, Ad₁+ D₂→ D
From departure intersection STP to the first intersection A₁Via
The adjacent intersection B₁₁The total distance D up to is obtained.

Next, referring to the rewriting data area RDA of the intersection netlist CRNL related to the adjacent intersection B ₁₁ stored in the buffer memory 11, it is checked whether the search order of the adjacent intersection B ₁₁ is (i + 1) (step 21).
1), which is NO here, so as to correspond to the adjacent intersection B ₁₁ in the intersection netlist CRNL related to the intersection B ₁₁ , (a) of the first-order intersection A ₁ currently focused on. Sequential number, (b) Cumulative distance D (= B from the starting point intersection STP to the adjacent intersection B ₁₁ )
d ₁ ), is stored in the rewrite data area RDA, and (c)
(I + 1) = 2 as the search order of the adjacent intersection B ₁₁
Is stored in the rewrite data area RDA (step 21).
2). Then, returning to step 209, the buffer memory 1
By referring to the intersection netlist CRNL related to the first-order intersection A ₁ stored in No. 1, it is checked whether an intersection adjacent to the currently-selected first-order intersection A ₁ still remains, and if there is, the same processing is performed. repeat.

When the route search section 14 returns to step 209, since the adjacent intersections B ₁₂ and B ₁₄ are present, the route search section 14 determines YES. And, of these, for the second adjacent intersection B ₁₂ ,
After calculating the cumulative distance D from the departure point intersection STP to the adjacent intersection B ₁₂ (step 210), the data rewriting area RDA of the intersection netlist CRNL corresponding to the adjacent intersection B ₁₂ stored in the buffer memory 11 is referred to. It is checked if the search order is already 2 (step 211), and since it is NO, the sequential number of the primary intersection A ₁ and the cumulative distance D = in the data rewriting area RDA.
Bd ₁₂ and search order 2 are registered (step 212). Then, returning to step 209, the remaining adjacent intersections B ₁₄ stored in the intersection netlist CRNL of the intersection A ₁ are processed in the same manner as described above.

When the processing for B ₁₄ is completed, the route search unit 14 checks whether there is another primary intersection (step 301 in FIG. 7), and here, A ₂ , A ₃ ,
Since A ₄ exists, the process after step 209 in FIG. 6 is performed by using A ₂ as a new first intersection (step 304).

Intersection netlist CRNL for intersection A ₂
There are first to fourth adjacent intersections B _{21 to} B ₂₄ in
B ₂₄ = Starting point intersection STP, so the fourth adjacent intersection B ₂₄
Is removed and processed in step 209. And first B
For _21, the route searching unit 14 refers to the intersection network list CRNL intersection A _2, to calculate the total distance D from the departure point intersection STP to the adjacent intersection B ₂₁ passing through the first primary adjacent intersection A ₂ ( Steps 209, 210).

Next, the route search unit 14 refers to the intersection netlist CRNL of the adjacent intersection B ₂₁ stored in the buffer memory 11 and checks whether the degree of the adjacent intersection B ₂₁ is 2 (step 211), but B ₂₁ = B ₁₂ , and the degree of the adjacent intersection B ₁₂ is already 2, so the result is YES. This is the intersection B adjacent to the first intersection A _1
12 indicates that it has been processed (data of (a) to (c) above has been stored). In this case, first, it is stored in the rewrite data area RDA of the intersection netlist CRNL related to the adjacent intersection B _12. The total distance * D = Bd ₁₂ from the given starting point intersection STP is compared with the size of the distance D obtained in step 210 this time (step 213).

If D << D, the adjacent intersection B
The sequential number of the i-th intersection A ₁ stored in the rewriting data area RDA of the intersection netlist CRNL of ₁₂ (= B ₂₁ ) is the i-th intersection A ₂ currently focused on.
And the cumulative distance * D is rewritten with D = Bd ₂₁ (step 214). D
If ≧ * D, RDA is not rewritten. after this,
Returning to step 209, similar processing is performed for the next adjacent intersection related to the first intersection A ₂ .

Thereafter, the same processing is sequentially repeated,
In the check in step 302 of FIG. 7, the (i +
1) Destination intersection DSP among all the following intersections
When it is determined to be YES, first, in the intersection netlist CRNL related to the destination intersection DSP stored in the buffer memory 11, the destination intersection DSP stored in the rewrite data area RDA. Store in the rewriting data area RDA in the previous (m-1) th intersection corresponding to the (mth intersection) and the intersection netlist CRNL related to the (m-1) th intersection. The previous (m-2) th intersection corresponding to the certain intersection, ... In the intersection netlist CRNL related to the secondary intersection, the primary intersection stored in the rewriting data area RDA, the departure An intersection node sequence that connects the ground intersections STP in the reverse order to determine the shortest optimum route viewed from the cumulative distance and configures the optimum route from the departure intersection STP to the destination intersection DSP. As a basic guide route. Then, referring to the road layer in the map data, a node data string in which simple nodes (nodes that are not intersections) are interpolated between intersection nodes in the basic guide route is set as final guide route data and stored in the guide route storage unit 15. (Step 305). At this time, an intersection identification flag is set for an intersection node on the guide route. The guidance route searched this time is shown in Fig. 8.
It is assumed that it is as shown by the broken line GR.

When the route guidance is completed, the navigation controller 10 inputs vehicle position data, vehicle direction data, and vehicle speed data from the GPS receiver 2 (step 306).
The map image drawing unit 18 sends the map data including the vehicle position to the CD.
-Read from the ROM 1 to the buffer memory 11, and use the read map data to draw in the video RAM 19 a map image with the vehicle position as the center and the north facing upward. Next, from the guide route data stored in the guide route storage unit 15, a guide route selected in the drawing area of the map image is selected, and a guide route which is overlaid on the map image and emphasized in a color different from that of a normal road is thickly drawn. draw. Then, a vehicle position mark with the vehicle azimuth direction facing the center of the map image is drawn. The image drawn in the video RAM 19 is read by the video conversion unit 20, converted into a predetermined video signal, output to the display device 4, and displayed on the screen (step 30).
7). As a result, a map image MP including the vehicle position is displayed on the screen together with the guide route GR and the vehicle position mark CM as shown in FIG. 10 (1).

Next, the measuring unit 16 measures the duration of the state where the vehicle speed is 20 km / h or less based on the vehicle speed data input from the GPS receiver 2 so that the vehicle speed is 20 km.
It is checked whether or not / h or less (step 308), and if NO, a timer (not shown) built in the measuring unit 16 is stopped (step 309). After that, the navigation controller 10 returns to step 306 and inputs new vehicle position data, vehicle azimuth data, and vehicle speed data from the GPS receiver 2, and a map image centered on the new vehicle position is used as a guide route and vehicle. It is drawn together with the position mark and displayed on the screen (step 307). Below, the vehicle speed is 20km
The same process is repeated as long as / h is exceeded. As the vehicle runs, the screen scrolls the map showing the guide route with the vehicle position fixed at the center. The driver can reach the destination by traveling along the guide route.

If the traffic jam determination vehicle is caught in the traffic jam indicated by the symbol S in FIG. 8 while traveling on the guide route, the vehicle speed becomes slow. Vehicle speed is 20 due to traffic jam
When it becomes less than km / h, the measuring unit 16 determines YES in step 308. At this time, it is checked whether or not the timer is counting time (step 310). Since it is NO here, the timer is started to start counting time (step 31).
1). After that, the navigation controller 10 returns to step 306 and inputs new vehicle position data, vehicle azimuth data, and vehicle speed data from the GPS receiver 2,
A map image centering on the new vehicle position is drawn together with the guide route and the vehicle position mark and displayed on the screen (step 307). Then, again, the measuring unit 16 determines that the vehicle speed is 20.
If it is less than km / h (step 308), if YES, then it is checked whether the timer is currently counting (step 3).
10) Since it is YES this time, the time count data of the timer indicating the duration time during which the vehicle speed is 20 km / h or less is output to the determination unit 18.

When the discriminator 18 inputs the measured time data of the timer, it checks whether the time exceeds 3 minutes (step 31).
2). If NO, the re-search command is not output yet, and the navigation controller 10 returns to step 306 and performs the same processing as described above. After that, when the duration of the vehicle speed is 20 km / h or less for more than 3 minutes, the determination unit 18 determines YES in step 311 because the vehicle is involved in the traffic jam, and the route search unit 14 In response, a re-search command for the optimum route to the destination is output.

The route searching unit 14 which has received the re-searching command from the route re-searching judging unit 17 finds the nearest route which is a certain distance L ₀ or more away from the current position in the forward direction of the vehicle from the guide route data already searched. The nearest intersection that is more than L ₁ (= L ₀ + L) away from the intersection is selected (step 313). Here time was CP ₁ and CP ₂ in FIG. 8, CP from the route search unit 14 CP ₁
The map data in the range of up to ₂ is read from the CD-ROM 1 to the buffer memory 11, and CP ₁ to C are read using the intersection netlist CRNL in the read map data.
Bear up P _2, it searches the horizontal search method the shortest path other than the guide route to it previously described (Step 3
14).

At this time, before starting the re-search process, the CP
₁To CP₂At each intersection on the guidance route to
CP for the corresponding intersection netlist CRNL₁From
CP ₂Distance between adjacent intersections along the guide route to
Is replaced with an extremely large distance. This gives C
P₁To CP₂The original guide route that connects to
Being overwhelmed and being searched as the shortest route
Not CP₁To CP₂Tie up to and lead until then
The shortest route among the various routes that bypass the road (one point in Fig. 8
The chain line GR ') is searched. After this, the route search unit
14 is the initial guide route stored in the guide route storage unit 15.
CP of the data₁To CP₂This time I will re-search
Corrected guidance route data by replacing
Is performed (step 315).

After this, the navigation controller 1
0 returns to step 306 in FIG. 7, and a map image centering on the vehicle position is drawn together with the corrected guide route and vehicle position mark and displayed on the screen (see FIG. 10 (2)). Therefore, the user can easily and swiftly reach the destination while avoiding the traffic congestion only by traveling along the new guidance route without searching for the detour by trial and error to avoid the traffic congestion.

In the above embodiment, the re-search command is issued.
The received route search unit 14 is in front of the traveling direction of the vehicle on the guide route.
A certain distance L from the current position₀Crossing point CP₁
And L ₁(= L₀+ L) intersection CP₂Between
Guide you by re-searching for a route that allows you to bypass traffic congestion.
I tried to modify a part of the road data, but CP₁Eyes
Re-search for a route that connects to the target area and bypasses the congestion, and invite
The entire route data may be modified. Also,
CP1 on the guide route when re-searching₁-CP₂Exchange between
Determine the distance between adjacent intersections in the difference netlist CRNL
Replacing the same with a larger distance
Is the distance between adjacent intersections in the intersection netlist CRNL
Simple shortest route and intersection netlist using
Set the distance between adjacent intersections in CRNL to the width between adjacent intersections
The shortest route weighted according to width (width is large)
The shorter the distance between adjacent intersections is treated, the more
The distance between adjacent intersections in the list list CRNL
Shortest route with type priority weighted according to road type between
(For highways and national roads, the actual distance between adjacent intersections is
Re-search for all three (treat shorter)
15 and the map image drawing unit 18 stores these 3
The two detour routes are simultaneously drawn on the map image and displayed on the screen.
The user can select any of the three detours.
One may be selected so that the vehicle can travel.

[0044]

As described above, according to the present invention, the duration of time when the vehicle speed is kept constant or less is measured, and the measured duration is compared with a predetermined reference value to determine whether a traffic jam occurs. , When it is determined that a traffic jam is occurring during route guidance, the map data is used to re-search for the optimum route that bypasses the traffic jam from the current position to the destination and corrects the guidance route data. With this configuration, even if you are caught in a traffic jam while traveling to your destination after receiving route guidance, you will automatically receive the route guidance by switching from the current position to the optimal route that can bypass the traffic congestion and reach the destination. It is possible to reach a desired destination quickly.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of data stored in a guide route storage unit.

FIG. 3 is an explanatory diagram showing a data structure of a road layer.

FIG. 4 is an explanatory diagram of an intersection netlist.

FIG. 5 is a first diagram showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 6 is a second diagram showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 7 is a third view showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 8 is an explanatory diagram showing roads around a vehicle position.

FIG. 9 is an explanatory diagram of a route search method.

FIG. 10 is an explanatory diagram showing a screen display example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CD-ROM 2 GPS receiver 3 Operation part 4 Display device 10 Navigation controller 11 Buffer memory 12 Cursor position calculation part 13 Destination setting part 14 Route search part 15 Guided route storage part 16 Measuring part 17 Discrimination part 18 Map image drawing part 19 Video RAM 20 Video converter

Claims (1)

[Claims] 1. A map data storage means for storing map data, a vehicle position detection means for detecting a vehicle position and a vehicle direction, and an automatic search for an optimum route connecting a departure place and a destination using the map data, Route search means to be stored in the guide route storage means as guide route data, map image drawing means for drawing a map image around the vehicle position together with the vehicle position mark using the map data, and displaying it on the screen on the display means, and guide route data In a vehicle-mounted navigation device equipped with a route guidance means for performing route guidance using, a vehicle speed detection means for detecting a vehicle speed, and a measurement means for measuring the duration of a state in which the vehicle speed is below a certain level, Compare the duration measured by the measuring means with a predetermined reference value,
And a determining unit that determines whether or not a traffic jam occurs, and when the route searching unit determines that a traffic jam is occurring during the route guidance, the route searching unit uses the map data to bypass the traffic congestion from the current position. The in-vehicle navigation device is characterized in that the optimum route connecting to the destination is re-searched and the guide route data stored in the guide route storage means is corrected.