JP2902207B2 - Route guidance method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route guidance method, and more particularly, to a route guidance method for connecting a plurality of waypoints connecting a departure place and a destination in order.
The present invention relates to a route guidance method for an in-vehicle navigator configured to sequentially guide a route as a vehicle travels.

[0002]

2. Description of the Related Art There is an on-vehicle navigator that provides guidance for driving a vehicle so that a driver can easily reach a desired destination. In this in-vehicle navigator, a vehicle position is detected, map data around the vehicle position is read from a CD-ROM, a map image is drawn on a V-RAM, and a vehicle position mark is superimposed on a predetermined position on the map image. Draw,
While converting the image in the V-RAM into a video signal, the image is output to a CRT display device and displayed on a screen. Then, as the current position changes due to the movement of the vehicle, the vehicle position mark on the screen is moved, or the vehicle position mark is fixed at the center of the screen and the map is scrolled, so that the map around the vehicle position is always displayed. Information can be understood at a glance.

A map stored in a CD-ROM is divided into regions of appropriate longitude and latitude widths according to the scale level, and roads are represented by vertices (nodes) represented by longitude and latitude coordinates. ). A portion connecting two or more nodes is called a link. As shown in FIG. 16, the road data included in each map includes a road list RLDT, a node table NDTB, and an intersection configuration node list CRDT.
Of which the road list RLDT is
Regarding the road, data indicating the type of road such as a national road, an expressway, and other roads, data indicating the total number of nodes on the road, the number of each node constituting the road on the node table NDTB, and the width of the road between nodes. Etc. The width data of the n-th node number indicates the width of a road (link) connecting the node of the n-th node number and the node of the (n + 1) -th node number. The intersection configuration node list CRDT is, for each intersection on the map, a set of numbers on a node table NDTB of a node (referred to as an intersection configuration node) closest to an intersection on a link connected to the intersection, and a node table NDTB. Is a list of all nodes on the map, coordinate information (longitude, latitude) for each node, an intersection identification flag indicating whether or not the node is an intersection, and, if it is an intersection, indicating a position in the intersection configuration node list; If it is not an intersection, it is composed of a pointer or the like pointing to the road link to which the node belongs.

By the way, an on-vehicle navigator searches for an optimal guide route from a departure place to a desired place using map data, stores the guide route data in a guide route memory, and uses the route guide mode. During traveling, predetermined route guidance information is displayed on the screen using the guidance route data stored in the guidance route memory (the guidance route is displayed in a specific color in bold,
There is a route guidance function for displaying route guidance at an intersection existing ahead in the traveling direction of a vehicle, or performing a predetermined route guidance from a departure place to a desired place. According to such a route guidance function, it is possible to easily and reliably reach a desired place at the time of excursions, business, and the like simply by traveling according to the route guidance information displayed on the screen.

However, if the departure place is far from the destination, the small scale map data includes not only expressways and national roads but also fine roads such as prefectural roads and city roads. It is difficult to find the optimal guidance route from the destination to the destination at one time. Even if the search is possible, it takes a long time to complete the search and the guidance route for storing the guidance route data Requires a large amount of memory. Therefore, conventionally, when the departure point and the destination are far apart, the search for the guidance route is divided into two stages, a primary search and a secondary search. First, after the destination is set, a large-scale upper-layer map is set. Primary search is performed using data (including only highways and national roads as road data) to find transit points (for example, major intersections on major roads) that connect the departure point to the destination in order. . And while driving,
Each time a vehicle approaches a certain stopover, the lower-scale map data (lower-level road data as well as major roads,
A secondary search is performed using fine roads such as prefectural roads, city roads, etc.), and a detailed guidance route connecting the certain transit point to the next transit point is obtained. After passing, route guidance to the next stopover is performed based on the guidance route data obtained this time.

FIGS. 17 to 20 are flow charts showing the route guidance processing in the vehicle navigator of the sequential search type as described above.
FIG. 21 is an explanatory diagram of data stored in the guidance route memory,
FIG. 22 is an explanatory diagram of a route guidance method, and FIG. 23 is an explanatory diagram of a screen display example. As shown in FIG. 22, when the final destination is C, a map selection operation is performed on the operation panel to display a desired map on the screen before starting traveling (step 80 in FIG. 17).
1, 802), after setting the route guidance mode (steps 803, 804), scrolling the map on the screen by operating the cursor keys to set the cursor to the desired final destination C (steps 805 to 810); The destination input key is pressed (step 901 in FIG. 18).

[0007] Then, the on-vehicle navigator sets the point closest to the cursor position on the upper road as the final destination C (step 902), and selects one of the map data stored in the map information storage means such as a CD-ROM. The primary search is performed with reference to the map data of the upper layer having a large scale, and the point closest to the current position on the main road of the upper layer is set as the departure point S, and the optimal shortest distance connecting the departure point S to the final destination C is determined. The route is searched, and the upper-level intersection node sequence that constitutes the searched route is stored in the waypoint memory as the waypoint data (step 903). Since the stopover data is selected from the intersection nodes defined in the upper-level map data, the intersection nodes defined only by the lower-scale map data of the smaller scale are included even if they exist on the same road. Not. Therefore, when viewed in the lower layer, the data becomes discrete. Here, for the sake of simplicity, it is assumed that the via points are a first via point A and a second via point B as shown in FIG. The final destination C is registered at the end of the waypoint memory as the last waypoint.

Next, the on-vehicle navigator connects the departure point S to the first stopover with reference to the lower scale map data of the map data stored in the map information storage means such as a CD-ROM. The optimum shortest route is secondarily searched, and the lower node row (including the intersection node and the simple node) constituting the searched route is used as the guide route data in the two storage areas on the 0 and 1 sides of the guide route memory. , And 0 in the area (steps 904 and 905, see the route A in FIG. 22 and the 0 side in FIG. 21). Since the secondary routed search route data is selected from intersection nodes and simple nodes defined in the lower-level map data, the intervals between the nodes are short,
It is accurate data.

When the start key is pressed on the operation panel (step 906), a map image including the current position in the center is displayed on the screen based on the lower layer map data including the current position (departure point) (step 907), and guidance is provided. From the data in the 0-side area of the route memory, read out what is in the map on the screen,
The emphasis guidance route highlighted in a predetermined color and superimposed on the map image is superimposed and displayed (step 908), and the transit point data included in the map on the screen is also read from the transit point memory to display the transit point mark (FIG. 19). Step 1001), a vehicle position mark is displayed at the center of the screen in the direction indicated by the vehicle direction (step 1002). As a result, first, as shown in FIG. 23A, an optimal enhanced guidance route from the departure point S to the first stopover A is displayed on the lower layer map around the departure point on the screen. Thereafter, when the vehicle starts running and the vehicle position changes, a map image around the current position is scroll-displayed on the screen according to the movement of the vehicle (step 1004), and the guidance stored in the 0-side area of the guidance route memory is stored. From the route data, the data that enters the map on the screen is read out, and the guidance route is displayed in a different color from the other roads in a bold color (step 1006). Is displayed (step 1007), and a vehicle position mark is displayed at the center of the screen in a direction corresponding to the vehicle direction (step 1008). Therefore, the driver can easily know which road should be reached to reach the first stopover A.

[0010] Thereafter, when the vehicle approaches the first stopover A to a certain distance, the vehicle-mounted navigator refers to the lower-level map data of a small scale stored in the map information storage means such as a CD-ROM. A secondary search is made for an optimal route connecting the first stopover A to the second stopover B, and node sequence data constituting the searched route is used as guide route data in FIG.
As shown by 0, it is stored in the one side area of the guidance route memory (steps 1009, 1011 and 1012, see the route b in FIG. 22).

Until the vehicle passes through the first stopover A, the above-described enhanced guidance between the departure point S and the first stopover A is performed based on the guide route data stored in the area 0 on the guidance line route memory. The route guidance by the route display is performed (see FIG. 23 (2)), but after passing through the first stopover A, the route is switched to the guidance route data stored in the one side area of the guidance route memory. Then, route guidance is performed between the first stopover A and the second stopover B by displaying the enhanced guide route (steps 1005, 1013, 1006, see FIG. 23 (3)).
This allows the driver to drive on any road,
The user can easily know whether the vehicle can reach the second stopover B.
Thereafter, when the vehicle travels and approaches the second stopover B to a certain distance, the vehicle-mounted navigator again searches for an optimal route connecting the second stopover B to the final stopover (final destination) C. Then, the node string data constituting the searched route is stored in the zero-side area of the guide route memory as the guide route data (see steps 1009, 1011, 1012, and route C in FIG. 22). At this time, the guidance route data between the departure point S and the first stopover A stored in the area 0 is deleted.

Until the vehicle passes through the second route point B, the route between the first route point A and the second route point B is described above, based on the guidance route data stored in the one side area of the guidance route memory. We perform route guidance, but the second stopover B
After passing through, the route is switched to the guide route data stored in the 0-side area of the guide route memory, and the route guide is displayed between the second stopover B and the final destination C by displaying the enhanced guide route. Perform (steps 1005, 1013, 1006). Thereby, the driver can easily know which road should be traveled to reach the final destination C.

On the other hand, for example, while traveling from the second stop B to the third stop C, if the driver mistakes the road at the intersection CP and deviates from the guidance route (c), the in-vehicle navigator performs step YES is determined in 1013. At this time, by referring to the map data and vehicle position data and heading data, re-search starting point intersection in the frontmost in the vehicle direction of travel when viewed from the vehicle position at that time (see V ₁ of the FIG. 24) e (step 1101 in FIG. 20), an optimal guide route from the re-search starting point e to the stopover headed therefrom is searched using the map data, and the searched guide route data is stored in the MF of the guide route memory. It is stored in the side area (step 1102, see the route in FIG. 24). And FIG.
It returns to step 1003 of No. 9.

Thereafter, since route guidance is performed based on the guidance route data searched again this time, even if the vehicle deviates from the previous guidance route, it is possible to reach a desired transit point.

[0015]

SUMMARY OF THE INVENTION However, the conventional
In-vehicle navigator, when deviating from the guidance route,
The intersection closest to the vehicle ahead in the direction is the starting point for re-search
Therefore, as shown in FIG. 24, the vehicle speed is high and the guidance route is searched again.
When the search is completed, the re-search starting point e is set to the vehicle position (V _Two)
The guidance route that came backward and re-searched for the vehicle position
It may not be on top. In such a case, the screen displays
Make a U-turn to drive the indicated guidance route
In the situation where the U-turn is difficult
Does not help route guidance by re-searched guidance route
There was a problem. From the above, the object of the present invention is
Route guidance that does not make the guided route incompatible with the vehicle position
To provide guidance.

[0016]

In the above problems BRIEF SUMMARY OF THE INVENTION The present invention, certain points or with reference means for detecting the current position of the vehicles, the map data stored in Jo Tokoro map information storage means
And means for searching an optimum guidance route connecting to Luo predetermined point, a guidance route memory for storing guidance route data searched by using the guide route data stored in the induction path memory, the predetermined point from the one point Means for performing a predetermined route guidance to the vehicle, and means for determining, as a starting point of the re-search, a point on the traveling road which is separated by a predetermined distance or more ahead in the traveling direction when the vehicle deviates from the guidance route. Then, referring to the map data, at least from the re-search starting point
A means for searching for an optimal guidance route connecting to a point on the guidance route to a predetermined point to an intermediate point on the guidance route and storing it in the guidance route memory, and thereafter, using the guidance route data searched again this time,
It is achieved by providing the re-search origin or Racing shelf predetermined means for performing route guidance.

[0017]

According to the present invention, when the vehicle deviates from the guidance route, a point on the traveling road that is more than a predetermined distance ahead of the traveling direction is determined as a starting point of the re-search by referring to the map data. With reference to the map data, an optimal guidance route connecting the re-search starting point to a point on the guidance route at least to the predetermined point is searched for and stored in the guidance route memory. Using,
Re search origin or Racing performs shelf predetermined route guidance. With this, a new guidance route that connects to the waypoint that has been headed since it deviated from the guidance route is searched, and when the search is completed, the starting point of the re-searched guidance route comes behind the vehicle position, and not occur state as that not on the guidance route that the vehicle position is re-searched, since an appropriate guide route for the vehicle position, using the guidance route based on a new guidance route, reliably to a predetermined place Will be able to reach.

[0018]

1 is an overall configuration diagram of a vehicle-mounted navigator embodying a route guidance method according to the present invention. In the figure, 1
Is a CD-ROM serving as map data storage means, and 2 is an operation panel. Left, right, up, and down cursor keys, route guidance mode setting keys, destination input keys, keys for map search, enlargement / reduction, etc. , A start key and the like. Reference numeral 3 denotes a vehicle position / vehicle direction detecting unit which includes a direction sensor and a vehicle speed sensor, and detects a vehicle direction and a vehicle position by self-contained navigation, and 4 denotes a CRT display device, which inputs a video signal to display a map on a screen and a cursor mark. , Vehicle position mark, enhanced guidance route,
It is displayed together with an intersection guidance image and a waypoint mark.
The vehicle position / vehicle direction detector 3 also outputs vehicle speed data.

Numeral 10 is a navigation controller having a microcomputer structure, which determines an optimal guidance route by simulation calculation, and converts a map image around the vehicle position into a cursor mark, a vehicle position mark, an enhanced guidance route, an intersection guidance image if necessary. CRT with stopover mark
It is displayed on the screen of the display device 4. Among them, 11 is a buffer memory for temporarily storing the map data read from the CD-ROM 1, and 12 is a cursor position calculator, which is a cursor key of the operation panel 2, a map search, a key for enlargement / reduction, etc. When a selection operation or a cursor movement operation is performed, the longitude and latitude corresponding to the center of the map on the screen are calculated and output as the cursor position. Reference numeral 13 denotes a map image drawing unit, which is provided on the operation panel 2 before starting traveling.
The desired map data (may include surrounding map data) selected with keys for map search, enlargement / reduction, etc.
A new map data is read out from the ROM 1 to the buffer memory 11 and a map image is drawn on a first V-RAM, which will be described later, and a new cursor position data input from the cursor position calculation unit 12 is changed according to a cursor operation. While reading the map data from the CD-ROM 1 to the buffer memory 11, the map image in the first V-RAM is rewritten so that the cursor position is always at the center, and the first
A cursor mark is drawn at the center of the V-RAM. Also,
During traveling (after the start key of the operation panel 2 is pressed), the map image drawing unit 13 stores new map data in the CD-ROM as necessary as the vehicle position data output from the vehicle position / vehicle direction detecting unit 3 changes. ROM 1 to buffer memory 11
The first V-
Rewrite the map image in RAM. Further, the map image drawing unit 13 sets the vehicle position mark to the first VR based on the vehicle direction data input from the vehicle position / vehicle direction detection unit 3 during traveling.
At the center of the AM, the drawing is performed in the direction corresponding to the vehicle direction. In the route guidance mode, the first V-V is currently selected from the guidance route data stored in the guidance route memory described later.
Enter guidance route data that falls within the range of the map image drawn in the RAM, draw a guidance route that is emphasized in a different color from the other roads in a thicker color, and specify a guide route at a location corresponding to a transit point of the map image. Draw a stopover mark for.

Reference numeral 14 denotes a destination setting unit, which is set to a route guidance mode on the operation panel 2 before starting traveling, and after the cursor at the center of the screen is matched with the final destination by operating the operation panel 2, the destination is set. When the input key is pressed, the output of the cursor position calculator 12 at that time is set as destination data. A transit point memory 15 sequentially registers transit point data that is primarily searched for by a later-described guidance route search unit, as shown in FIG. The transit point memory also stores a pass identification flag for each transit point. This passage identification flag is set when the vehicle has passed.

Reference numeral 16 denotes a guidance route search unit, and when the final destination is set by the destination setting unit 14, the vehicle position detection unit 3
Enter current location data (departure location data) from CD-R
From the OM 1, the buffer memory 11 reads from the current location to the destination and reads a number of upper-level map data of a large scale (including only highways and major roads as national roads as road data). By referring to the map data obtained, for example, using the shortest distance as an index, a primary search based on a number of simulation calculations is performed, and a transit point (for example, a main intersection on a main road) connecting the departure point to the destination in order is determined. Are registered in the waypoint memory 15 in order from the departure point side. At this time, the final destination is registered at the end of the transit point memory 15 as the final transit point. When the primary search is completed, the guidance route search unit 16
Indicates map data of a lower layer of a small scale level around the current location from the CD-ROM 1 to the buffer memory 11 (this map data includes not only main roads but also fine roads such as prefectural roads and city roads as road data). With reference to the optimum guide route from the current location to the first stopover, a series of nodes constituting the guide route (each node is longitude / latitude coordinates, an intersection identification flag CPF, a stopover identification flag KF
Is stored as guide route data in one of two storage areas of a guide route memory described later. The coordinates of each node in the node sequence are extracted from the node table of the map data (see NDTB in FIG. 16), and the intersection identification flag CPF is set in the node table N.
It is obtained by referring to the DTB, and is set to 1 when the node is an intersection. The transit point identification flag KF is set to 1 in the case of a node corresponding to a transit point.

Further, the guidance route search unit 16 monitors the distance between the i-th way point where the vehicle is currently heading and the position of the vehicle after the vehicle starts traveling in the route guidance mode (after the start key is pressed). When approaching a fixed distance, the coordinates of the i-th stop, the next (i + 1) -th stop, and the next (i + 2) -th stop are input from the stop-point memory 15 and the CD-ROM is input.
1 to the buffer memory 11 from the i-th stop, via the (i + 1) -th stop, to the (i + 2) -th stop, and reading various lower-level map data and referring to the read map data, A simulation calculation is performed on the route, and using the shortest distance as an index, an optimal guide route that connects the i-th stop via the next (i + 1) -th stop and further to the next (i + 2) -th stop is obtained. A series of node trains (each node includes longitude / latitude coordinates, an intersection identification flag CPF, and a waypoint identification flag KF) constituting the guidance route are used as guidance route data in two storage areas of a guidance route memory described later. Of these, it is stored in an area different from the area stored last time.

Reference numeral 17 denotes a guidance route memory, which has a 0-side area and a 1-side area for storing two route guidance data as shown in FIG. In addition, it has a flag area for storing a flag MF (0; 0 side, 1; 1 side) indicating which data is currently being route-guided in the 0-side area and the 1-side area. FIG. 3 shows a state where guidance route data connecting the departure point to the second stopover is stored in the 0 side area, and guidance route data connecting the first stoppoint to the third stoppoint is stored in the 1 side area. Show.

Reference numeral 18 denotes an existing link detection unit for detecting a link where a vehicle is present during traveling.
1, a node (forward node) located closest to the vehicle ahead in the traveling direction on the traveling road with reference to the map data, the own vehicle position data, and the vehicle orientation data stored in the traveling road. A node (rear node) located on the rear side in the traveling direction and closest to the vehicle is determined. Reference numeral 19 denotes a guidance route deviation detection unit that checks whether the vehicle has deviated from the guidance route while traveling. Both or one of the front node and the rear node detected by the existing link detection unit is used for the current route guidance in the guidance route memory. It is detected whether or not the guidance route has been deviated by checking whether the node is no longer present in the used node train.

Reference numeral 20 denotes a first distance calculation unit which stores the guidance route memory 17 when the vehicle does not deviate from the guidance route.
From among the guidance route data used for the current route guidance, the own vehicle position data and the vehicle orientation data, the waypoint where the vehicle is currently heading is specified, and the distance between the waypoint and the own vehicle position is specified. Is calculated and output to the guidance route search unit 16. 2
Reference numeral 1 denotes a passage determination unit, and when the vehicle has not deviated from the guidance route, the backward node detected by the existing link detection unit stores the guidance route data in the guidance route data used for the current route guidance in the guidance route memory 17. When it matches the waypoint, it is determined that the waypoint has passed.

Reference numeral 22 refers to the lower layer map data, the vehicle position data and the vehicle direction data stored in the buffer memory 11 when the vehicle deviates from the guidance route, and looks forward on the traveling road in the vehicle traveling direction. Out of the vehicle distance from the vehicle position by a predetermined distance L, and searches for the nearest intersection, and uses it as the starting point of the guidance route re-search. When the re-search starting point is detected by the re-search starting point detecting unit, the guidance route searching unit 16 determines the shortest guiding route connecting the re-search starting point to the next via point via the via point that has been headed up to that point. Using the map data in the lower layer of the CD-ROM 1, the obtained route data is stored in the route memory 17.
The information is rewritten and stored in the same area as that used for the route guidance. The predetermined distance L used for detection of a re-search start point by the re-search start point detection unit 22
When the re-search for the guidance route is completed by the guidance route search unit 16, the value is set to a value as short as possible so that the vehicle does not pass the re-search starting point and may be a fixed constant distance. If it is early, when the re-search for the guidance route is completed, it is possible that the vehicle has passed the re-search start point.・ Vehicle heading detector 3
L = s · k (k is a fixed constant) (1) or L = s · k + L ₀ (L ₀ is a predetermined fixed distance) in accordance with the vehicle speed s detected at 2) It is supposed to be variably set by the equation.

Reference numeral 23 denotes a rerouting guidance route data stored in the guidance route memory 17, self-vehicle position data, vehicle According to the azimuth data, the re-search starting point is behind the vehicle traveling direction and the vehicle does not exist on the re-search guidance route, in other words, the vehicle has passed the re-search guidance route. The re-search guidance route suitability determination unit checks whether the re-search guidance route has become an inappropriate re-search guidance route. When the re-search guide route suitability determination unit 23 determines that the vehicle is not suitable, the re-search start point detection unit 22 returns to the vehicle position at that time again on the currently traveling road by a predetermined distance L or more in front of the vehicle traveling direction. , The nearest existing intersection is determined as the starting point of the guidance route re-search.
Then, the guide route search unit 16 determines the shortest guide route connecting the re-search start point detected by the re-search start point detection unit to the next way point through the way point that has been heading to the previous way point.
It is determined using the map data in the lower layer of the D-ROM 1, and the obtained guidance route data is stored in the guidance route memory 17 in the same area as that used for the route guidance. However, the predetermined distance L used by the re-search starting point detection unit 23 to detect the re-search starting point is the following equation instead of the above equation (1) or (2): L = sk ′ (k ′ is larger than k) a certain constant) (3) or, L = s · k '+ L 0 ··· (4) or, L = s · k + L 0' (L 0 ' is a large fixed constant than L ₀₎ ··・ Set according to the formula of (5) and make L larger than the first time.

When the departure from the guidance route has not occurred, one of the guidance route memory 17 uses the guidance route data of the side currently used for route guidance, the own vehicle position data, and the vehicle heading data to determine one in the vehicle traveling direction. A second distance calculation unit that identifies an intersection (guide target intersection) existing in front of the vehicle and calculates the distance from the own vehicle position, 25 is an intersection guidance image drawing unit, and the distance calculated by the second distance calculation unit is constant. When the distance is within the distance (for example, 200 m), the guidance target intersection is stored in a second V-RAM, which will be described later, by using the intersection configuration node list (see CRDT in FIG. 16) in the map data stored in the buffer memory 11. The intersection shape figure is drawn with the north facing upward, and the guidance target intersection in the guidance route data on the side currently used for route guidance in the guidance route memory 17 is proposed. The 2V-R from the positional relationship of the immediately preceding node of the target intersection (intersection ingress node), the node after one of the guide target intersection (intersection exit node)
Arrows indicating the intersection approach direction and the intersection exit direction are drawn on the intersection shape figure of AM, and further, distance data is input from the second distance calculation unit 24, and the distance from the vehicle position to the guidance target intersection is indicated by "○○". "m".

Reference numeral 26 denotes a first V-RAM having an area corresponding to one screen of the CRT display device, and includes a map image drawn by the map image drawing unit 13 (including a cursor mark when the cursor is operated before starting traveling; While the vehicle is traveling in the route guidance mode, a vehicle position mark, an emphasis guidance route with a different color from other roads, and a stopover mark are stored. Reference numeral 27 denotes a second V-RAM having an area corresponding to 1/9 screen of the CRT display device, and stores the intersection guidance image drawn by the intersection guidance image drawing unit 25. Reference numeral 28 denotes a synthesizing unit which adds a second image to the map image drawn on the first V-RAM 26 at a predetermined time when intersection guidance is required (when the vehicle position approaches within a certain distance from the guidance target intersection).
The intersection guidance image drawn on the V-RAM 27 is synthesized and output. When intersection guidance is not required (when the vehicle position is more than a predetermined distance from the guidance target intersection or when the vehicle deviates from the guidance route), the first combination is not performed.
Only the map image drawn on the V-RAM 26 is output. 2
Reference numeral 9 denotes a video conversion unit that converts the image data output from the synthesis unit into a video signal and outputs the video signal to the CRT display device 4.

4 to 10 are flowcharts showing the route guidance processing of the navigation controller 10, FIG. 11 is an explanatory diagram of a guidance route searching method, FIG. 12 is an explanatory diagram of a guidance route re-searching method, and FIGS. 13 and 14 are CRTs. FIG. 9 is an explanatory diagram of a screen display example of the display device 4 and will be described below with reference to these drawings. In FIG. 11, S is the departure point, A is the first stopover,
B is a second stop, C is a third stop, and D is a final destination (fourth stop). In FIG. 12, E is a re-search starting point and E 'is a re-searching starting point.

First, when an operation of selecting a map of a desired area at a desired scale is performed by operating a map search, a key for enlargement / reduction, etc. on the operation panel 2, the map image drawing unit 13 reads the desired map from the CD-ROM 1. The data is read out to the buffer memory 11 and a map image is drawn on the first V-RAM 26. The map image data drawn on the first V-RAM 26 is output as it is to the video conversion unit 29 via the synthesis unit 28, converted into a video signal by the video conversion unit 29, and output to the CRT display device 4. The CRT display device 4 displays a map on the screen based on the input video signal (steps 101 and 102 in FIG. 4). Subsequently, when the route guidance mode key is pressed on the operation panel 2 and the setting operation of the route guidance mode is performed (steps 103 and 104), the navigation controller 10 causes the navigation point memory 15 and the guidance route memory 1 to operate.
7 and then the map image drawing unit 13 sets the first VR
A cursor mark is drawn at the center of the AM 26, and the cursor mark is displayed at the center of the map image on the screen (step 1).
05). At this time, the cursor position calculator 12 calculates the cursor position at the center of the screen (step 106).

When the cursor keys on the operation panel 2 are operated, the cursor position calculation unit 12 causes the cursor position (longitude,
(Coordinates of latitude) are calculated (steps 107 and 108), and the map image drawing unit 13 changes the CD-
While reading predetermined map data from the ROM 1 to the buffer memory 11, a map image is drawn on the first V-RAM 26 so that the center is always the cursor position, and a cursor mark is drawn on the center of the first V-RAM 26. As a result, the map on the screen moves according to the cursor operation with the cursor mark displayed at the center of the screen (steps 109 and 110).

When the driver wants to go to D as the final destination (see FIG. 11), when the cursor mark on the screen reaches D, the cursor operation is stopped and the destination input key of the operation panel 2 is pressed (FIG. 11). 5 step 201). Then, the destination setting unit 14 sets the cursor position data output from the cursor position calculation unit 12 at that time as the destination data, and outputs the data to the guidance route search unit 16 (step 2).
02). The guidance route search unit 16 uses the map data of the upper layer having a large scale among the map data stored in the CD-ROM 1 and sets the point closest to the destination data on the upper road of the upper layer as the final destination D. On the other hand, on the upper layer main road, a point closest to the current position detected by the vehicle position / vehicle surrounding detection unit 3 is set as a starting point S, and a primary search is performed with reference to the upper layer map data. An optimum shortest route connecting from S to the final destination D is searched for, and the upper-level intersection node sequence constituting the searched route is registered as the waypoint data in the waypoint memory 15 in order from the departure point (step 203). Each stopover data is selected from the intersection nodes defined in the upper-level map data, so even if they exist on the same road, the intersection nodes defined only by the lower-scale map data of the smaller scale are Not included. Therefore, when viewed in the lower layer, the data becomes discrete. Here, for the sake of simplicity, it is assumed that the transit points are a first transit point A, a second transit point B, and a third transit point C as shown in FIG. The final destination D is registered at the end of the waypoint memory 15 as the last waypoint.

After the primary search is completed in this way, the guidance route search unit 16 first sets the flag MF of the guidance route memory 17 to 0 (step 204), and then sends the vehicle position / vehicle direction detection unit 3 to the current location. Data is input as departure point data, and first and second stopover data are input from the stopover memory 15. And CD
-Repeat the simulation calculation while reading out a large number of map data from the departure point S through the first stopover A to the second stopover B from the ROM 1 with the lower scale map data from the ROM 1 to the buffer memory 11 to repeat, for example, the shortest distance. Is searched as an index, and a series of nodes constituting the guidance route is stored in the guidance route memory 17 in the following manner.
It is stored as guidance route data in the 0-side area indicated by the MF (step 205, refer to the route a in FIG. 11 and the 0-side area in FIG. 3).

Then, when the start key is pressed on the operation panel 2 (step 206), the map image drawing section 13 reads the map data of the lower layer around the current position (departure point) from the CD-ROM 1 to the buffer memory 11, and the center is displayed. A map image is drawn on the first V-RAM 26 so as to be a departure place (step 207). Then, the map image drawing unit 13 reads nodes included in the map display area of the screen from the guidance route data stored in the 0-side area of the guidance route memory 17, and differs from other roads based on these data. An enhanced guidance route for route guidance is drawn on the first V-RAM 26 in a bold color (step 208), and the screen is displayed on the first to fourth via points A to D with reference to the via point memory 15. If there is something in the map display area, the first V
-Draw a predetermined stopover mark at a corresponding location in the RAM 26 (step 209). Then, a vehicle position mark is drawn in the center of the first V-RAM 26 in a direction corresponding to the vehicle direction (step 210). As a result, a map around the departure point with the vehicle position mark at the center departure point is displayed on the screen, and the guidance route is highlighted on the screen in a color different from other roads, so that it can be seen at a glance. It is possible to determine along which road the vehicle can reach the first stopover A and the second stopover B (see FIG. 13A).

After step 210, the navigation controller 10 proceeds to the flow of FIG. 7 and thereafter, but periodically generates an interrupt and performs the interrupt processing of FIG. That is, when the vehicle starts traveling, the vehicle position / vehicle direction detecting unit 3 sets the departure point S
The vehicle position and the vehicle direction are detected every time the vehicle travels for a certain distance by using the self-contained navigation with the vehicle as a starting point, and the vehicle position data and the vehicle direction data are output. The vehicle position / vehicle direction detecting unit 3
Also outputs the vehicle speed data at each time point. In the interrupt processing of FIG. 6, the map image drawing unit 13 inputs the vehicle position data and the vehicle azimuth data and checks whether a change has occurred in the vehicle position (steps 301 and 302), and if there is no change, returns to the flow of FIG. When there is a change in the vehicle position, the CD-R
While reading predetermined map data including the position of the own vehicle from the OM 1 to the buffer memory 11,
The map image is drawn so that the center is the vehicle position (step 303). Then, in the guidance route memory 17, MF
Is read out of the guidance route data stored on the 0 side shown in FIG. 4 and the nodes included in the map display area of the screen are read, and based on these data, the first VR is thickened in a color different from other roads.
The emphasis guidance route is drawn on the AM 26 (step 30).
4) If any of the first to fourth via points A to D is included in the map display area of the screen, a predetermined via point mark is drawn at the corresponding location (step 305). Then, a vehicle position mark is also drawn in the center of the first V-RAM 26 in a direction corresponding to the vehicle direction (step 306). As a result,
As the vehicle travels, the map on the screen moves so that the center is always at the vehicle position, and the highlighted guidance route and the waypoint mark move together with the map. If the driver travels so that the vehicle position mark does not deviate from the guidance route, the driver can easily reach the waypoints A and B. When the process of step 306 is completed, the process returns to the flow of FIG.

In the flow after FIG. 7, first, the existence link detection unit 18 extracts the map data stored in the buffer memory 11 and the vehicle position data and the vehicle azimuth data detected by both the vehicle position / vehicle detection unit 3. Detects an existing link composed of a front node located closest to the vehicle ahead in the traveling direction on the road on which the vehicle is traveling and a rear node located closest to the vehicle behind the traveling direction (step 40 in FIG. 7).
1). Subsequently, the guidance route deviation detection unit 19 stores, in the guidance route memory 17, in the guidance route data of the 0-side area indicated by the MF, any one of the front node and the rear node detected by the existence link detection unit. It is detected that the vehicle has not existed and has deviated from the guidance route (step 402). If not, the first distance calculator 20 calculates
In the current waypoint memory 15, from the waypoint data closest to the departure point and the vehicle position data among the waypoints for which the passage identification flag has not yet been set in the current waypoint memory 15, Then, the distance between the nearest first stopovers A to which the vehicle is heading is calculated (step 403). If the distance calculated by the first distance calculation unit 20 is equal to or more than a predetermined distance and is still far from the first stopover, the guidance route search unit 16 does not search for the next guidance route (step 404). NO).

Next, the passage determining unit 21 determines that the backward node detected by the existing link detecting unit is
It is determined whether or not the vehicle has passed the first stopover A by checking whether or not it matches the stopover in the guidance route data of the 0-side area indicated by the MF (step 405). If the vehicle has not yet passed, the second distance calculation unit 24 stores the guidance route memory 17
From the guidance route data of the 0-side area indicated by the MF, the own vehicle position data and the vehicle azimuth data, the intersection closest to the vehicle existing ahead in the vehicle traveling direction (intersection targeted for guidance)
At the same time, the distance from the own vehicle position to the guidance target intersection is calculated (step 406). Then, the intersection guidance image drawing unit 25 checks whether the distance calculated by the second distance calculation unit 24 is within a certain distance (step 407). If the distance is not within the predetermined distance, the intersection guidance image drawing unit 25 causes the synthesizing unit 28 to output only the map image drawn in the first V-RAM 26 as it is to the video conversion unit 29 and display only the map image alone (step 408). ). Then, the navigation controller 10 returns to Step 401,
Hereinafter, similar processing is performed.

When the distance is within the predetermined distance in step 407, the intersection guidance image drawing section 25 reads out all the intersection configuration nodes for the guidance target intersection from the buffer memory 11, and stores the guidance target intersection node in the second V-RAM 27 in the center. The intersection shape figure is drawn with the north facing upward, and the node immediately before (the entry node) and the node after (the entry node) the guidance target intersection node from the guidance route data used for the current route guidance. Read out node)
An arrow for traveling direction guidance is drawn from the entry node through the guidance target intersection node to the exit node, and based on the distance data obtained by the second distance calculation unit 24, “「 m ”
In this way, characters indicating the distance to the guidance target intersection are also drawn, and the intersection guidance image is drawn in the second V-RAM 27. Then, the synthesizing unit 28 synthesizes the intersection guidance image drawn on the second V-RAM 27 with the map image drawn on the first V-RAM 26, outputs the combined image to the video conversion unit 29, and outputs the intersection guidance image on the map image. A composite display is performed (step 408). As a result, as shown in FIG. 13 (2), the driving direction guidance at the intersection existing ahead in the vehicle traveling direction on the guidance route is displayed on the screen. Looking at the guidance display, the driver can correctly travel at the intersection along the guidance route.

As the vehicle approaches the guidance target intersection, the distance display in the intersection guidance image becomes shorter, and after passing through the intersection, if the vehicle is within a certain distance to the next guidance target intersection, immediately An intersection guidance image for the next guidance target intersection is displayed (step 40).
6 to 409), if the user is far from the next guidance target intersection, the display of the intersection guidance image is temporarily stopped (NO in step 407, 408), and then the display is within a certain distance to the next guidance target intersection. Then, the display of the intersection guidance image is restarted.

On the other hand, when the vehicle has approached the first stopover A to a certain distance and the answer is YES in step 404, the guidance route search unit 16 refers to the stopover memory 15 to check the stopovers which have not passed yet. Because four remain (step 4
At 10), three pieces of transit point data that have not passed are input from the closest one to the departure point. Here, the first stopover A,
A second stop B is a third stop C. And CD-R
From the first stopover A to the second from the OM1 to the buffer memory 11
A number of lower-level map data including an area extending from the viaway B to the third viaway C is read out, a simulation is calculated using the shortest distance as an index, and the first viaway A to the second viaway B are calculated. An optimum route up to the third stopover C is searched for, and the searched route data is stored in the one-side area of the guide route memory 17 opposite to the area indicated by the MF (step 411, FIG. The route of 11 b, FIG.
1). If the number of transit points that have not passed yet is two or less in step 410, the search for the guidance route is not performed.

When the vehicle approaches the first stopover A, the first stopover A enters the screen. At this time, the display of the enhanced guide route by the map image drawing unit 13 is performed by the guide route memory 1.
Based on the guidance route data on the 0-side area of No. 7, not only the guidance route to the first stopover A but also the guidance route from the first stopover A to the second stopover B is included.
Even if the first stopover A is an intersection, it is not unknown in which direction to travel at the intersection (FIG. 1).
3 (3)). Furthermore, in the present embodiment, if the first stopover A is an intersection, an intersection guidance image is displayed from a place approaching within a certain distance, so that the direction in which the vehicle should travel at the first stopover A is more accurately determined. It becomes possible to grasp.

[0043] The first vehicle is not deviated from the guidance route.
When the passing node A passes and the rear node detected by the existence link detecting unit 18 matches the first passing point, the passing determining unit 21 determines that the first passing point has been passed (YE in step 405).
S) At this time, after setting the passage identification flag corresponding to the first stopover A in the stopover memory 15 (step 5 in FIG. 8).
01), it is determined whether there are two or more transit points that have not passed yet (step 502).
F is inverted to 1 (step 503). Then, the process returns to step 406 in FIG. Therefore, after that, based on the guidance route data on one side of the guidance route memory 17, the display of the emphasized guidance route and the display of the intersection guidance image are performed for the first to third via points A to C. Become
The driver can use the route guidance to obtain the second stopover B and the third stop.
It is possible to easily reach the waypoint C.

When the vehicle approaches the second stopover B to a certain distance, the guide route searching unit 16 inputs the second stopover data, the third stopover data, and the fourth stopover data from the stopover memory 15. , CD-ROM 1 to buffer memory 11
First, a number of lower-level map data including an area from the second viaway B to the fourth viaway D via the third viaway C is read out, a simulation is calculated using the shortest distance as an index, and the second The optimum route from the site B to the fourth viaway D via the third viaway C is searched, and the searched guide route data is stored in the guide route memory 17 on the 0 side opposite to the area indicated by the MF. In the area (step 404,
410, 411, the path C in FIG. 11).

When the vehicle approaches the second stopover B and the second stopover B enters the screen, the map image drawing unit 13
Is displayed in the guidance route memory 17.
Based on the guide route data of the side area, not only the guide route to the second stop B but also the third stop C from the second stop B
Therefore, even if the second stopover B is an intersection, it is not unknown in which direction to travel at the intersection. Also, the second
If the stopover B is an intersection, an intersection guidance image is displayed from a place approaching within a certain distance, so that it is possible to more accurately grasp the direction in which to travel at the second stopover B.

The vehicle is not deviated from the guidance route,
When passing through the waypoint B and the rear node detected by the existing link detection unit 18 matches the second waypoint, the passage determination unit 21 determines that the vehicle has passed through the second waypoint (YE in step 405).
S) At this time, the passage identification flag corresponding to the second stopover B in the stopover memory 15 is set to 1 (step 50 in FIG. 8).
1). Then, since there are two transit points that have not yet passed, the flag MF in the guidance route memory 17 is inverted to 0 (steps 502 and 503). Therefore, after that, based on the guidance route data on the 0 side of the guidance route memory 17, the display of the emphasized guidance route and the display of the intersection guidance image for the second to the fourth stop (the final destination) D are performed. Therefore, the driver can easily reach the third stop C and the fourth stop D by the route guidance.

However, when the vehicle approaches the third stopover C to a certain distance and the answer is YES in step 404 in FIG.
The guide route searching unit 16 does not search for a guide route because there are only two or less unpassed transit points (N in step 410).
O).

When the vehicle approaches the third stopover C and the third stopover C enters the screen, the map image drawing unit 13
Is displayed in the guidance route memory 17 as 0.
Based on the guide route data of the side area, not only the guide route to the third stop C, but also the third stop D to the fourth stop D
Therefore, even if the third stopover C is an intersection, it is not unknown in which direction to travel through the intersection. Also, the third
If the stopover C is an intersection, an intersection guidance image is displayed from a place approaching within a certain distance, so that the direction to travel at the third stop C can be grasped more accurately.

If the vehicle does not deviate from the guidance route, the third
When the passing node C passes through and the rear node detected by the existence link detecting unit 18 matches the third passing point, the passing determination unit 21 determines that the third passing point has been passed (YE in step 405).
S), the passage identification flag corresponding to the third stopover C in the stopover memory 15 is set (step 501 in FIG. 8), but the MF is not inverted because there is no unpassed stopover (step 502). NO). Therefore, based on the guidance route data on the 0 side of the guidance route memory 17, the second
The display of the emphasized guidance route and the display of the intersection guidance image are performed for the waypoint B to the fourth waypoint D. When NO is determined in step 502, it is determined whether the vehicle has passed this time is the last stopover (step 504). Thereafter, when the vehicle reaches the fourth stopover D without deviating from the guidance route, the navigation controller 10 cancels the route guidance mode and ends the route guidance (step 405 in FIG. 7 and step 5 in FIG. 8).
01, 502, 504, 505), Step 10 in FIG.
Return to 3.

On the other hand, for example, while traveling from the second stop B to the third stop C (MF is assumed to be 0), as shown in FIG.
When a wrong road is entered on the road different from the guidance route, the guidance route deviation detecting unit 19 detects that the vehicle has deviated from the guidance route (YES in step 402 in FIG. 7). Then, if the intersection guidance image drawing unit 25 has been displaying the intersection guidance image, the combining by the combining unit 28 is stopped and the display of the intersection guidance image is stopped (steps 601 and 602 in FIG. 9). Next, the re-search starting point detection unit 2
2 is based on the map data stored in the buffer memory 11, the vehicle position data, the vehicle direction data, and the vehicle speed data (s) detected by the vehicle position / vehicle direction detection unit 3.
Looking forward from the current vehicle position (V _{1 in} FIG. 12) on the road on which the vehicle is traveling in front of the current vehicle position (V _{1 in} FIG. 12), a search is made for the nearest intersection, and the starting point E of the guidance route re-search is searched.
(Step 603). At this time, since the first re-search start point is detected, the predetermined distance L is determined by (1) or (2) described above.

Next, when there are two or more non-passing transit points in the transit point memory 15 in the transit point memory 15 (YES in step 604), the guide route searching section 16 selects two of the transit points near the departure point, here the third transit point. The location C and the fourth stop D are read out, and the shortest guide route from the re-search start point E to the next stop D via the second stop C heading up to that point is set to CD.
-Obtained by using the map data in the lower layer of the ROM 1 and store the obtained guidance route data in the guidance route memory 17 by rewriting in the 0-side area indicated by the MF which has been used for the route guidance up to that time (step 605, see route d in FIG. 12). Then, the re-search guide route suitability determination unit 23
Is input of the vehicle position data and the vehicle direction data from the vehicle position / vehicle direction detection unit 3 and refers to the guidance route data (research guidance route data) connecting E → C → D obtained this time, and searches again for the search start point. E is behind the vehicle traveling direction, and there is no vehicle on the re-search guidance route,
In other words, it is checked whether the vehicle has passed the re-search guidance route and has become an inappropriate re-search guidance route (step 606). Or re-search starting point E at the check is in the forward vehicle traveling direction (see V ₂ in FIG. 12), or, if even the re-search starting point E is in the rear of the vehicle the vehicle position if entered the re-search guidance route (see V ₃ of FIG. 12), it is determined to be relevant. At this time, the current re-search guidance route data is left as it is. Then, the existence link detection unit 1
8, the presence link of the vehicle is detected (step 607), and based on the detection result, the guidance route deviation detecting unit 19 checks whether the guidance route is deviating (step 608). Return to 403.

The map image drawing unit 13 and the intersection guidance image drawing unit 25 display the enhanced guidance route based on the re-search guidance route data stored in the 0-side area of the guidance route memory 17 as shown in FIG. And the intersection guidance image is displayed. Therefore, even if the vehicle deviates from the original guidance route from the second viaway B to the third viaway C (route B in FIG. 11), the vehicle travels according to the new route guidance. By going, it is possible to easily reach the third stopover C and the fourth stopover D. Moreover, when the vehicle comes near the third stopover C, the guidance route ahead of the third stopover C is also displayed on the screen as shown in FIG.
Even if the third stopover is an intersection, it does not become unclear which direction to travel to the third stopover. Further, as shown in FIG. 23, when the re-search starting point is located at the intersection e closest to the vehicle in the forward direction of the vehicle as viewed from the vehicle position (V ₁ ) at the time when the departure from the guidance route is detected, the guidance route is re-started. Since it takes a certain amount of time to complete the search, when the re-search for the guidance route is completed, the vehicle has already passed the re-search starting point e and has deviated from the re-searched guidance route (f) ( V ₂ ), there was a problem that the guidance route displayed on the screen became useless,
In the present embodiment, such a problem does not occur because the re-search starting point is at least a predetermined distance L ahead of the vehicle position at the time when the departure from the guidance route is detected.

When the vehicle travels along the re-search guidance route and arrives at a position a fixed distance before the third via point C, the guidance route search unit 16 checks whether there are three or more unpassed via points. (Steps 404 and 410 in FIG. 7), which is NO here, does not rewrite the guidance route memory 17. Then, even after the vehicle has passed through the third stopover C along the guide route, route guidance from the third stopover C to the fourth stopover D is performed using the guideway data of the area on the 0 side. . In addition, when there is only one untransited transit point at step 604 in FIG. 9, the guidance route search unit 16 searches for an optimal guidance route connecting the re-search starting point to the untransited transit point. , MF (step 609).

[0054] Further, Wakashi, when the determination in step 606, the vehicle position is coming at the V ₄ in FIG. 12, when it becomes irrelevant, re-search starting point detection unit 22 is a buffer memory 1
1 and the vehicle position data, the vehicle direction data, and the vehicle speed data (s) detected by the vehicle position / vehicle direction detection unit 3 to look forward on the traveling road in the vehicle traveling direction. In this case, the nearest intersection is searched for within the predetermined distance L or more from the vehicle position, and is set as the starting point E 'of the guidance route re-search (step 610). At this time, since the second search start point is detected, the predetermined distance L is determined by the above (3), (4), or (5), and is set longer than the first search.

Next, if there are two non-passing transit points in the transit point memory 15, the third transit point C and the fourth transit point D, the guidance route searching section 16 repeats the search from the re-search starting point E ′ to that point. The shortest guidance route connecting the third viaway C to the fourth viaway D is calculated using the map data in the lower layer of the CD-ROM 1, and the obtained guidance route data is stored in the guidance route memory 17. Of the first re-search guidance route data is stored by rewriting in the same area on the 0 side (steps 701 and 702 in FIG. 10 and route E in FIG. 12). The presence link detection unit 18 detects the presence link of the vehicle (step 607 in FIG. 9), and based on the detection result, the guidance route deviation detection unit 19 checks whether the guidance route is deviating (step 608). When it is no longer inside, the process returns to step 403 in FIG.

After that, the map image drawing unit 13 and the intersection guidance
The image drawing unit 25 stores the
Enhanced guidance based on the stored re-search guidance route data
The route is displayed and the intersection guidance image is displayed.
By making L longer than the time of the last search, the search starting point E 'is found again.
Therefore, when the re-search for the guidance route is completed,
The position is still V in FIG._FiveAs shown in the figure, before the re-search start point
Or V in FIG. ₆On the re-searching guidance route as shown
The route will not be an inappropriate guidance route,
Route guidance based on route data ensures that you reach the desired stopover
Can be reached.

According to the above-described embodiment, when the vehicle approaches the i-th stop, a guidance route connecting the i-th stop to the (i + 2) -th stop via the (i + 1) -th stop is searched for. The vehicle is stored in the guidance route memory, and when the vehicle passes through the i-th stop, the route guidance is performed using the guidance route data connecting the i-th stop to the (i + 2) -th stop.
Thereafter, when the vehicle approaches the (i + 1) -th stop, the guidance route to the (i + 1) -th stop and the guidance route ahead from the (i + 1) -th stop are displayed together on the screen. Even if the (i + 1) stopover is an intersection, it can be easily grasped in which direction the vehicle can travel to the (i + 2) th stop along the guidance route. In addition, the (i)
+1) If the stopover is an intersection, an intersection guidance image indicating the traveling direction at the intersection is also displayed, so that the traveling direction can be accurately known even at a complicated intersection.

Further, since the vehicle has deviated from the guidance route, when re-searching for the guidance route to the viaway to which the vehicle has been heading, the intersection closest to the vehicle within the predetermined distance L ahead of the vehicle traveling direction must be Since it was set as the starting point of re-search,
When the re-search is completed, a situation does not occur in which the vehicle has already passed the guidance route and becomes an inappropriate guidance route. In addition, since the predetermined distance L is variably set to an appropriate value according to the vehicle speed, an appropriate guidance route can be obtained even when the vehicle speed is high. Furthermore, if the re-searched guide route is inappropriate, L is increased to obtain the re-search start point, and the guide route from the re-search start point to the via point to which the search was performed is searched again. As a result, there is no case in which appropriate route guidance for the next stopover becomes impossible.

In the above-described embodiment, the route guidance is performed by both the display of the emphasized guidance route and the display of the intersection guidance image. However, the route guidance may be performed by either one of them. Further, when the vehicle has deviated from the guidance route, when re-searching the guidance route to the waypoint to which the vehicle was heading, as shown in FIG. 15, a candidate of the guidance route connecting the re-search starting point E to the waypoint is determined. For example, a plurality of shortest and second shortest distances are obtained, and a re-search starting point E is determined with respect to the vehicle position V at the time when the search for the guidance route is completed.
Is located behind the vehicle, and if there is no candidate on the guidance route where no vehicle is on the vehicle, remove the candidate, and select the shortest candidate as the final candidate that is suitable as the guidance route. You may make it register in a guidance route memory. In the case of FIG. 15, the route is removed, and the route is registered in the guidance route memory. Further, when the second re-search starting point is obtained, L or longer than the first time is set according to the formula (3), (4), or (5).
Alternatively, L may be set by equation (2). Furthermore, the re-search start point and the re-search start point need not be intersections, and may be simple nodes (nodes that are not intersections).

[0060]

As described above, according to the present invention, when a vehicle deviates from the guidance route, a point on the traveling road that is more than a predetermined distance ahead of the traveling direction is determined as a starting point of the re-search by referring to the map data. Then, referring to the map data, a place on the way along the guidance route from the re-search starting point to at least a predetermined point.
And searches for an optimum guidance route connecting the point stored in the guidance route memory, then, using the guidance route data re-search time, and configured to perform re-search origin or Racing shelf predetermined route guidance From, search for a new guidance route that connects to the waypoint that has been headed to because it deviated from the guidance route, and when the search is completed, the starting point of the re-searched guidance route comes behind the vehicle position, and There is no such situation that the vehicle position is not on the re-searched guidance route, and the vehicle becomes an appropriate guidance route for the vehicle position. Therefore, use the guidance route based on the new guidance route to reliably reach the predetermined place . become able to.

Further, by setting the predetermined distance to a value that varies in accordance with the vehicle speed, an appropriate re-guide route can be obtained even when the vehicle speed is extremely high.

Further, after re-searching the guidance route, if the starting point of the guidance route searched again this time is present behind the vehicle with respect to the own vehicle position, and the own vehicle position is not on the guidance route, the vehicle travels. A point on the middle road that is more than a predetermined distance ahead of the traveling direction is determined as a starting point of the re-searching, and then the map data is referred to at least a predetermined point from the starting point of the re-searching.
An optimum guidance route connecting to a point midway on the guidance route stored search to the guidance route memory that, then, by using the guidance route data currently retrocession search, retrocession search origin or Racing shelf predetermined path In the unlikely event that the re-searched guidance route is inappropriate due to guidance,
A point that is the same as the previous time with respect to the own vehicle position at that time, or a point that is separated by a predetermined distance or more longer than the previous time as a re-search starting point,
Since a search for a new guidance route is performed again, a situation in which appropriate route guidance for heading to a predetermined place is not possible does not occur.

At least a predetermined point from the re-search starting point
When searching for an optimal guidance route that connects to an intermediate point on the guidance route , a plurality of candidates are obtained, and after the plurality of candidates are obtained, the starting point of the guidance route searched again this time with respect to the own vehicle position is the vehicle. By refining one optimal guidance route by excluding a candidate that is present behind and that does not have its own vehicle position on the guidance route, it is possible to search for a guidance route once.
An appropriate guidance route can be determined for the position of the vehicle.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an on-vehicle navigator embodying a route guidance method according to the present invention.

FIG. 2 is an explanatory diagram of data stored in a waypoint memory.

FIG. 3 is an explanatory diagram of data stored in a guidance route memory.

FIG. 4 is a first flowchart showing a route guidance process of a navigation controller.

FIG. 5 is a second flowchart showing the route guidance processing of the navigation controller.

FIG. 6 is a third flowchart showing the route guidance processing of the navigation controller.

FIG. 7 is a fourth flowchart showing the route guidance processing of the navigation controller.

FIG. 8 is a fifth flowchart showing the route guidance processing of the navigation controller.

FIG. 9 is a sixth flowchart showing the route guidance processing of the navigation controller.

FIG. 10 is a seventh flowchart showing the route guidance processing of the navigation controller.

FIG. 11 is an explanatory diagram of a guidance route search method.

FIG. 12 is an explanatory diagram of a guidance route re-searching method.

FIG. 13 is an explanatory diagram of a screen display example of the CRT display device.

FIG. 14 is an explanatory diagram of a screen display example of the CRT display device.

FIG. 15 is an explanatory diagram of another guide route re-searching method.

FIG. 16 is an explanatory diagram showing a configuration of road data in map data.

FIG. 17 is a first flowchart showing a conventional route guidance process.

FIG. 18 is a second flowchart showing a conventional route guidance process.

FIG. 19 is a third flowchart showing a conventional route guidance process.

FIG. 20 is a fourth flowchart showing a conventional route guidance process.

FIG. 21 is an explanatory diagram of data stored in a guidance route memory.

FIG. 22 is an explanatory diagram of a conventional guide route searching method.

FIG. 23 is an explanatory diagram of a conventional screen display example.

FIG. 24 is an explanatory diagram of a method for re-searching a guide route having a problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CD-ROM 2 Operation panel 3 Vehicle position / vehicle direction detecting unit 4 CRT display device 10 Navigation controller 13 Map image drawing unit 15 Intermediate location memory 16 Guidance route searching unit 17 Guidance route memory 19 Guidance route deviation detecting unit 22 Research starting point Detection unit

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G09B 29/10 G01C 21/00 G08G 1/0969

Claims (5)

(57) [Claims] 1. A stored map data to the optimal guidance route searched by the navigation route memory connecting from one point with reference to the predetermined <br/> point of the guide route data stored in the induction path memory In the route guidance method of performing a predetermined route guidance from the certain point to a predetermined point using the method, when the vehicle deviates from the guidance route, referring to the map data, a predetermined distance ahead of the traveling road on the traveling road. A point that is farther away is determined as a starting point of the re-search, and then, by referring to the map data, an optimum guiding route connecting the re-search starting point to at least a halfway point on the guiding route to the predetermined point is searched, and the guiding route is determined. stored in memory, then, using the guidance route data re-search time, it has to perform re-search origin or Racing shelf predetermined route guidance, route guidance method comprising. 2. The route guidance method according to claim 1, wherein the predetermined distance is a value that varies according to a vehicle speed. 3. After re-searching the guidance route, when the starting point of the guidance route searched again this time is present behind the vehicle with respect to the own vehicle position and the own vehicle position is not on the guidance route, the vehicle travels. A point on the middle road that is more than a predetermined distance ahead of the traveling direction is determined as the starting point of the re-searching, and then the map data is referenced to connect a point on the guidance route from the starting point of the re-searching to at least the predetermined point on the way. and searches for an optimum guidance route stored in the navigation route memory, then the feature using the guidance route data currently retrocession search, it has to perform induction retrocession search origin or Racing shelf predetermined path, the Route guidance method to do. 4. The route guidance method according to claim 3, wherein the predetermined distance at the time of finding the re-search start point is larger than that at the time of finding the re-search start point at the previous time. 5. At least a predetermined point from the re-search starting point
When searching for an optimal guidance route that connects to an intermediate point on the guidance route , a plurality of candidates are obtained, and after the plurality of candidates are obtained, the starting point of the guidance route searched again this time with respect to the own vehicle position is determined. A route guidance method, characterized in that one optimal guidance route is finally determined excluding candidates that are present behind the vehicle and whose vehicle position is not on the guidance route.