JP2004085558A - Route-searching apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and surely perform a point-setting operation. <P>SOLUTION: This route-searching apparatus searches a traveling route between set start and end points, and guides the route based on the route searched. The apparatus includes an end point name display means (start point name display means) for displaying the set end point (start point) name during route searching. For example, the name of the end (start) point is a place name attached to an approaching point of the end (start) point searched based on the end (start) point, and further a place name is deduced from node information of a proximity node of the end (start) point. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to a route search device that automatically calculates an optimal traveling route connecting a set start point and an end point.
[0002]
[Prior art]
2. Description of the Related Art A navigation device that displays a map image in which a vehicle position mark is placed at the center of a screen on a liquid crystal screen or the like and provides an operator with route guidance has been put into practical use. The in-vehicle navigation device calculates a real vehicle position every moment from a GPS (Global Positioning System) device, a vehicle speed sensor, a direction sensor, and the like, and combines and displays the calculation result on a map screen.
[0003]
The in-vehicle navigation device includes, for example, a CD-ROM device storing map information, calls up necessary map information from the CD-ROM device, and displays a map image of a predetermined range centered on the vehicle position on a liquid crystal screen. indicate.
[0004]
In the CD-ROM storing the map information, data of a large number of information points (hereinafter referred to as nodes) on the map and data of a link connecting the two nodes are recorded together with the map image. Road intersections, dead ends, railroad crossings, railway stations, interchanges, etc. are selected as nodes. Also, latitude and longitude coordinate information, intersection names, traveling direction guidance, right / left prohibition, and the like are added as node information, and road widths, one-way streets, and the like are added as link information.
[0005]
Therefore, while traveling, the driver checks the actual vehicle position on the map screen, but by providing the navigation device with a function of searching the CD-ROM using the coordinates of the current position and the traveling direction, the driver can check the passing node ( The data of an approaching intersection can be used in real time.
[0006]
For example, a few hundred meters before the intersection, the traveling direction of the next intersection, the guidance of the lane, the presence or absence of one-way traffic, and the like are superimposed and displayed on the corner of the map screen. Further, the vehicle mark moving off the road on the map is automatically returned to the road.
[0007]
A route search function has been put into practical use as an additional function of a navigation device using node information and link information recorded on a CD-ROM. The route search function is a function in which the navigation device calculates an optimal traveling route before starting the actual traveling.
[0008]
After the driver sets the start point and the end point, the arithmetic unit of the navigation device automatically searches the CD-ROM, calls the necessary node information and link information, and sets the minimum distance, the shortest time, and the like. Calculate a traveling route that meets the conditions.
[0009]
For example, a CAD image is formed by connecting the coordinates of the nodes located along the travel route, and is combined with a map image and displayed. As a result, the travel route is indicated by a thick line on the map image.
[0010]
For example, when the vehicle actually travels on the set traveling route, each time the vehicle approaches an intersection, the distinction of right turn, left turn, and straight traveling for realizing the traveling route is synthesized and displayed on the corner of the map image. The speed limit, the lane guidance, and the like may be displayed together. In some cases, the navigation device is provided with a speaker and transmits such information by voice.
[0011]
As a method of calculating a travel route, a calculation method called the Dijkstra method is conventionally well known. In the Dijkstra method, the link lengths are sequentially added outward from the starting point, and the shortest path reaching the outer node is sequentially determined, and the shortest traveling path finally reaching the end point is determined. I do.
[0012]
However, in the Dijkstra method, the number of nodes to be calculated (the range involved in the calculation) increases in area as the calculation proceeds from the starting point to the outside, so that it takes a long time to calculate a long mileage, There is a problem that a large memory capacity is required for temporarily storing the operation data and enabling the operation device to perform the next operation.
[0013]
In addition, in the Dijkstra method, only a travel route that realizes the shortest distance in terms of length is obtained, and there is no guarantee that the travel time will be the shortest even if the travel route is adopted. That is, there is a possibility that an inefficient traveling route is obtained in view of the actual driving feeling and common sense, such as selecting a narrow road and repeatedly turning right and left.
[0014]
Therefore, an attempt has been made to use nodes information and link information recorded on a CD-ROM more effectively, weight nodes and links, and use the Dijkstra method in various correction formats.
[0015]
For example, in Japanese Patent Application No. 4-329564, the applicant of the present application has proposed a method of converting a link length into a link travel time and integrating the link travel time to calculate a “travel route that achieves the shortest travel time”.
[0016]
[Problems to be solved by the invention]
In a navigation device, there are many opportunities for a user to set a point such as an end point of a route search. For this reason, in the navigation device, it is a major problem to easily and surely perform the point setting operation.
[0017]
An object of the present invention is to solve this problem and to make it possible to easily and reliably perform a spot setting operation.
[0018]
[Means for Solving the Problems]
FIG. 1 is an explanatory diagram of the route search device according to the embodiment. Here, a route search device which is a technical field according to the present invention will be described with reference to symbols attached to the system configuration of FIG. However, the route search device of the present invention is not limited to the mode described in FIG. 1 and the description of the embodiment.
[0019]
In FIG. 1, a route guidance device includes a first storage unit 13 that stores information of a large number of nodes and links on a map in combination with a map image, and an operation capable of setting a start point and an end point of a desired traveling route. With reference to the means 11 and the node and link information stored in the first storage means 13, a travel route is calculated in such a manner that the determined travel route is sequentially extended from at least one of the start point and the end point. In the route search device having the calculating means 16 and the second storage means 15 for sequentially storing the determined traveling route and enabling the computing means 16 to calculate the subsequent part of the traveling route, And a pair of display means 17A and 17B capable of displaying the ratio of the travel route almost continuously, and detecting the ratio of the determined travel route to the entirety of the travel route to be determined. A detects the remaining amount of the storage capacity of the first measuring unit 16 and the second storage unit 15 for causing the display to substantially correspond to the ratio, and displays the remaining amount of the remaining amount on the other display unit 17B substantially. And a second measuring means 16 for performing the above-mentioned display.
[0020]
2. The route search device according to claim 1, wherein the route search device searches for a traveling route between the set start point and end point, and performs route guidance based on the searched route. And end point name display means for displaying the place name of the point.
Therefore, during the route search, the place name of the end point is displayed, and the end point can be easily and reliably confirmed.
[0021]
A route search device according to a second aspect of the present invention is the route search device according to the first aspect, further comprising start point name display means for displaying a place name of the set start point during the route search.
Therefore, during the route search, the place name of the start point is also displayed, and the start point can be easily and reliably confirmed.
[0022]
The route search device according to a third aspect is the route search device according to the first or second aspect, wherein the place name of the end point is a place name given to a point near the end point searched based on the end point. It is characterized by the following.
Therefore, during the route search, the place name where the data exists near the end point is displayed.
[0023]
According to a fourth aspect of the present invention, there is provided the route searching apparatus according to the third aspect, wherein the end point name display means calculates a place name from node information of a neighboring node of the end point searched based on the set point. It is assumed that.
Therefore, during the route search, the place name based on the node information near the end point is displayed.
[0024]
According to a fifth aspect of the present invention, in the route search apparatus of the second aspect, the place name of the start point is a place name given to a point near the start point searched based on the start point. Things.
Therefore, during the route search, the place name where the data exists near the starting point is displayed.
[0025]
According to a sixth aspect of the present invention, in the route search apparatus of the fifth aspect, the start point name display means determines a place name from node information of a neighboring node of the start point searched based on the set point. It is assumed that.
Therefore, during the route search, the place name based on the node information near the start point is displayed.
[0026]
【Example】
FIG. 1 is an explanatory diagram of a navigation device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a processing program, and FIG. 3 is an explanatory diagram of display contents. 1A shows a system configuration, and FIG. 1B shows a processing block diagram. 3A shows a screen configuration, and FIG. 3B shows a distance calculation.
[0027]
Here, a route search function is provided as an auxiliary function of the vehicle-mounted navigation device. The operator selects the route search processing, calls a map on the screen of the vehicle-mounted navigation device, and inputs a start point and an end point. Then, the map screen of the in-vehicle navigation device shifts to a screen indicating that the route search process is being performed, and the progress of the route search process and the usage of the memory capacity (total capacity−remaining capacity) are displayed in a bar graph.
[0028]
In FIG. 1, in the case of normal traveling, the processing unit 16 calculates the instantaneous vehicle position based on position and speed information obtained from the position sensor 14. Then, a map screen including the vehicle position is called from the map database 13 to form image data. The image data is displayed to the driver through the display unit 17 as a map screen in which the vehicle mark is located at the center of the screen.
[0029]
In addition, at the bottom of the map screen, the presence or absence of various information such as an intersection name, an intersection structure, lane guidance, a road name, a speed limit, and the like are displayed. Select and use.
[0030]
The map database 13 is composed of a CD-ROM playback device, searches for map image data, node information, and link information in response to a search command from the processing unit 16 and sends it to the processing unit 16. The memory 15 temporarily stores processing data when the processing unit 16 executes various arithmetic processing.
[0031]
When the driver specifies a start point (home) and an end point (destination) through the operation unit 11, the processing unit 16 searches the map database 13 for necessary node information and link information, and searches for a travel route of the shortest travel time. Is composed.
[0032]
When using the route search function, the operator selects a route search process through the input unit 11. The operator scrolls the map displayed on the screen of the display unit 17 through the input unit 11, selects a necessary map, and inputs a start point. Subsequently, the operator scrolls the map displayed on the screen of the display unit 17 through the input unit 11, selects a necessary map, and inputs an end point. Then, the operator instructs the start of the route search process.
[0033]
As a result, the map screen of the display unit 17 immediately shifts to a screen indicating that the route search processing is being performed, and displays two bar graphs 17A and 17B. The bar graph 17A indicates the progress of the route search process. The bar graph 17B displays the percentage of the capacity that can be allocated to the route search processing in the memory 15 that is already used at the present time.
[0034]
Thereafter, the operation is continued for several minutes. If the bar graph 17B does not reach 100% in the middle (unless the memory 15 overflows), all the arithmetic processing is completed and the operation progress of the bar graph 17A becomes 100%. Is displayed. The operator calls the recording operation screen of FIG. 9B on the display unit 17 and records the route search result on the IC card of the route data storage unit 12. It should be noted that the route search result may be sent to the route data storage unit 12 simultaneously with the completion of the calculation, and the recording operation may be automatically performed.
[0035]
The traveling route data thus formed includes node information of nodes constituting a traveling route from a start point to an end point, and link information of a link. In addition, guidance data such as right turn, left turn, straight ahead, and the like for forming the traveling route is added to the node information.
[0036]
The route data storage unit 12 sends the travel route data to the data processing unit 16 according to a command from the data processing unit 16. In addition, the IC card can be extracted from the route data storage unit 12 and the travel route data can be shared with an indoor system using a personal computer or the like.
[0037]
In FIG. 1B, the processing unit 16 in FIG. 1A can execute a route guidance process 22 in addition to the normal vehicle position detection process 23 and the above-described route search process 21. The route guidance process 22 is a process of providing real-time information to the operator during traveling based on the traveling route data recorded in the route data storage unit 12 in FIG.
[0038]
For example, the vehicle position is compared every moment with the set traveling route, and a message to notify a right turn is output in front of an intersection on the traveling route that requires a right turn. When the vehicle deviates from the traveling route, an alarm is output.
[0039]
The route search processing 21 includes: a point setting 21A for determining a start point and an end point based on an operator's designation; a route search 21C for actually calculating a route by a modified Dijkstra method or the like; and a calculated search result 21D. Each process of the search result management 21B to be recorded on the IC card in a form combined with other necessary selection information is included.
[0040]
2, bar graphs 17A and 17B are displayed on the display screen of the display unit 17 in FIG. 1 throughout the route search process. The bar graph 17A indicates the progress of the route search process, and the bar graph 17B indicates the usage rate of the memory 15.
[0041]
The “distance from the area being calculated to the end point” calculated in step 26 is compared with the “distance from start point to end point” calculated in step 25 at the bottom of the flowchart. Then, the ratio of the two is displayed in a bar graph (hereinafter referred to as an indicator) in step 28. The determined straight-line distance d and the remaining straight-line distance D-d to the end point are also displayed in characters.
[0042]
However, in the calculation processing of step 27, even if the remaining straight-line distance D-d becomes 0, it is treated as 90%. The indicator display of 100% is realized by step 30 at a time when all the route search processes are completed and the calculation result can be output.
[0043]
Similarly, the capacity m that is actually used (or is still empty) is compared with the maximum capacity M that can be allocated to the route search processing in the memory 15. Then, the ratio between the two is displayed as an indicator in step 29. The used capacity m and the remaining capacity M-m are also displayed in characters.
[0044]
In FIG. 3A, the display screen during the route search process displays the place names of the start point and the end point. The place name is determined from the node information of the neighboring node searched based on the start point and the end point set by the operator.
[0045]
In FIG. 3B, a straight line distance d for calculating the progress of the route search process is calculated from the XY coordinate values included in the node information. Further, the linear distance d is calculated once for each unit of the map.
[0046]
The road map data is normally managed as a unit as shown in FIG. When the point being searched is in the unit at the lower left (20, 20), the distance L to the unit where the goal exists is:
L2 = (60-20) 2+ (0-20) 2
Is required.
[0047]
As long as the search point exists in the unit being searched, distance calculation becomes unnecessary, and the processing can be speeded up. When the search point moves to the unsearched unit, distance calculation is performed, and when the distance becomes larger than the previous value, the indicator amount may be calculated based on the distance.
[0048]
By the way, if the search point exists in the unit under search for a long time, the indicator does not move. Therefore, the indicator amount is not increased at a time for one unit, and the period in which the search point exists in the same unit is increased for each minimum step of the indicator.
[0049]
FIG. 4 is an explanatory diagram of the location setting function. Here, a flowchart of the point setting prohibition check processing is shown.
[0050]
In FIG. 4, in the processing of the point setting 21 of FIG. 1B, setting of the start point and the end point using other than the detailed map is prohibited. The map recorded on the CD-ROM has a plurality of layers having different scales. By using a detailed map with a small scale, the position accuracy of the spot setting is ensured.
[0051]
The display map scale s of the map selected and displayed by the operator is compared with the allowable level S of roughness. The display map scale s is updated when the map is first drawn and when the display map is enlarged or reduced. If the map is not a detailed map, for example, a warning "Please set in detailed map" is displayed. In the case of a detailed map, actual point setting can be subsequently performed.
[0052]
5 is an explanatory diagram of creating parent-child relationship data of a node, FIG. 6 is an explanatory diagram of a hierarchical route search, and FIG. 7 is an explanatory diagram of a hierarchical route search result. 5A shows a processing flowchart, and FIG. 5B shows a data structure. Here, in order to perform a hierarchical route search, operation data used prior to the operation processing is arranged.
[0053]
5A, node information and link information retrieved from the map database 13 are temporarily stored in the memory 15 of FIG. 1A for each unit block map during the route search processing. Are provided sequentially. At this time, the parent-child relationship of the node is recorded in addition to the node information by referring to the node information of the map of the upper (lower) hierarchy. In other words, the identity of the XY coordinates of the node information is checked, and all nodes of the lower map overlapping with the nodes of the upper map are selected. This makes it possible to identify whether or not the calculation can be continued on the upper map when the calculation is performed on the nodes on the lower map.
[0054]
At this time, the condition is that (1) the map data has a hierarchical data structure, and (2) data indicating the parent-child relationship of nodes is not added between the maps between the layers.
[0055]
In FIG. 5B, the header of the map data 41 stores a map data number, a map scale, a data size, latitude and longitude information, and the like. The node table stores node coordinates, connection link information, presence / absence of parent-child nodes, and the like. The link table stores a start node number, an end node number, a type, a width, a traffic regulation, a link length, a link direction, and the like.
[0056]
The parent (child) node table 42 arranges parent (child) data 1 to n, and one parent (child) data 43 includes a parent (child) data number and a connection node number.
[0057]
In FIG. 6, a route search is performed on a higher-level road map as the distance from the start point and the end point of the search increases, using the relationship between the parent and child nodes in FIG. 5B. That is, the search is started on the lowest detailed map where the starting point is set, and the route search proceeds to the child node where the coordinate value of the child node of the detailed map matches the coordinate value of the parent node of the upper map and overlaps. Then, a route search is started by the parent node of the upper map. When the route search progresses on the upper map and reaches the parent node overlapping the parent node of the higher map, the route search by the parent node of the higher map is started.
[0058]
On the other hand, the route search proceeds from the end point side in the same procedure. The search is started on the lowermost detailed map, and the route search is advanced by changing to a higher map and a higher map. When the route search from the start point and the route search from the end point reach the common node for the first time, the route search is completed.
[0059]
The processing procedure is as follows. (1) The start and end nodes of the search are determined in the lowest hierarchy. (2) Using the parent node data to determine the route from the start node to the upper layer. (3) Using the parent node data from the end node, determine the route to the upper hierarchy. (4) Determine a route between upper layers. (5) The route is confirmed, that is, the route search in the vicinity of the change in the hierarchy is redone and optimized again. Note that in (2) and (3), the level to which the level rises is determined based on the distance between the start point and the end point and the road (data) density.
[0060]
In FIG. 7A, the search at the same level has the following problem. (1) When the highest hierarchy is used, there is no detailed route around the start and the goal. (2) When the lowest hierarchy is used, the search distance becomes short because the data size is large.
[0061]
In FIG. 7B, in the hierarchical search, the lowest hierarchy is used around the start and the goal. Use higher layers as you move away from the start or goal. Therefore, there is a detailed route around the start and goal.
[0062]
FIG. 8 is an explanatory diagram of the map cutout method in the search. In the figure, (a) shows the relationship between the end point direction and the link direction, and (b) shows the link weight for the end point.
Here, the link is weighted according to the traveling direction to promote the computation progress toward the computation end point.
[0063]
In FIG. 8A, the route search proceeds in the following procedure. (1) The direction Dg with respect to the search end point G is obtained from the searching node N. (2) The road direction Dl connected from the node N is obtained. (3) Find the difference Δd between Dl and Dg. The weight w is calculated from Δd. (5) The w obtained in (4) is used for weighting the link at the time of the route search. (6) When a search point reaches a boundary of map data, adjacent map data is read. Therefore, map data is not prepared beforehand by elliptical clipping or the like.
[0064]
In such a process, a map cutout function is also provided while being a part of the search process. This is because the search can easily proceed in the direction of the end point by shortening the link length toward the end point.
[0065]
In FIG. 8B, the weight is assigned smaller as Δd is 0, that is, as the degree of coincidence between the link direction and the end point direction is higher. As the degree of coincidence between the link azimuth and the end point azimuth decreases, the weight gradually increases and reaches the maximum in the opposite direction (180 degrees).
[0066]
The weighted and corrected link length L is: l: actual link length, W1: multiplication weight, W2: addition weight, w: weight for the search end point.
L = 1 × W1 × w + W2
Is required. A route search process using the Dijkstra method or the like proceeds in a form of sequentially integrating the weighted link lengths L.
[0067]
Next, the memory release function will be described. Here, the capacity of the memory 15 in FIG. 1A is saved during the route search processing.
[0068]
If the road data used in the search is divided into blocks as shown in FIG. 3B, the road data area of the section in which the path length from the search start point to all the nodes existing in the section is determined is stored in the memory 15. Release from above. Thereby, the memory consumption is reduced.
[0069]
Since it is not necessary to refer to the node once determined again, when the path length to all the nodes existing in one block is determined, the road data of that block is released and the memory capacity that can be used in the route search processing is increased. Let it. As a result, even when the memories 15 having the same capacity are used, the distance in which the route can be searched increases.
[0070]
Next, the data thinning function will be described. Here, the map data is sieved when the node information and link information used for the most recent calculation are stored in the memory 15 from the map database 13 of FIG.
[0071]
If the straight line distance to be searched is longer than a predetermined value, only a specific road type is extracted from the road data on the way, and stored in the memory 15 as map data. This extraction operation is performed by temporarily storing node information and link information for each block from the map database 13 in the memory 15, and the data of the extracted block is immediately released from the memory 15.
[0072]
Then, using only the node information and the link information related to the specific road type, a route search process from the block including the start point (or a nearby block) to the block including the end point is executed. The route search in the block including the start point and the route search in the block including the end point may be performed separately and the results may be added. As a result, the number of nodes to be searched is significantly reduced, and the processing speed is increased and the memory consumption is reduced.
[0073]
For example, a route search process is performed by extracting only highways. However, the initial data reading reads all roads. At this time, the interchange on the intermediate route of the expressway is a node forming a branch in the original data, but is a dead end having no connection relation in the data after the thinning. Therefore, there is no fear that the calculation range is extended outside the expressway with these nodes as base points.
[0074]
For example, (1) Only expressways are extracted, unnecessary areas are completely eliminated, and data is rearranged to reduce the time. In this case, since the useless area is eliminated, the data size is minimized, but compatibility with the original data recorded on the CD-ROM is lost.
[0075]
Alternatively, (2) the node number and the link number are changed only in the connection relationship while maintaining compatibility with the original data. If it is necessary to maintain compatibility with processes other than route search (display, route guidance, etc.), data is thinned out by this method. In this case, the overall data size is slightly larger, but compatibility with the original data can be secured through the node number and the link number. For example, if the format of “node number = 0, 1, 2,... N” is adopted in the order stored in the node table, the number of nodes does not decrease. The same applies to links.
[0076]
The condition for this function to function effectively is when the distance to search for a route is longer than the longest linear distance on land where no highway passes. The condition for starting this function is when the distance from the start point (or the end point) to the expressway is determined. Therefore, when the operator sets the start point and the end point, these conditions may be determined, and if the conditions are met, the function may be automatically switched to this function.
[0077]
Next, a function of searching for a route to a specific road type will be described. Assuming that a specific road type is, for example, an expressway, this function is synonymous with “route search function to the nearest expressway”.
[0078]
In a normal route search process, a route from a search start node to a search end node is obtained. In this case, the end of the search process is determined when the path length to the search end node is determined.
[0079]
On the other hand, in this function, the search end determination condition is changed to "when the path length to a node connected to a link of a specific road type is first determined". As a result, the subsequent arithmetic processing is executed by the same arithmetic method and arithmetic procedure as in the normal route search processing.
[0080]
In addition, a switch is provided for switching between a normal "route search process that does not specially treat an expressway" and a route search process using this function, and waits for an operator's command to switch the end condition of the search process.
[0081]
FIG. 9 is an explanatory diagram of a search result storage and update function. In the figure, (a) shows a recording method, and (b) shows a display screen. Here, an operation when the route search result is recorded on the IC card in the route data storage unit of FIG. 1A will be described.
[0082]
In FIG. 9A, the storage capacity of the SRAM of the IC card is used in an indeterminate form in which a fixed storage space is not divided in advance. On the other hand, the fixed type, in which the recording capacity is divided in advance by a fixed storage space, has problems such as the inability to store a route search result exceeding the storage space and the low overall storage efficiency.
[0083]
For example, when the SRAM 71 of 40 Kbytes is divided in advance into four storage addresses, a route search result of 10 Kbytes or more cannot be stored, and even if an empty space is generated for each storage address, it cannot be filled later.
[0084]
On the other hand, if the SRAM 72 of 40 Kbytes is used in an indefinite manner, a plurality of past route search results are truncated without forming an empty space on the way, and the storage efficiency is increased. Then, a new route search result can be stored in the empty space 72B.
[0085]
In FIG. 9B, when storing a new route search result, an operation screen 73 is output to the display unit of FIG. 1A. The operator operates the operation panel 74 while viewing the operation screen 73. As a result, the new route search result is recorded on the IC card, and the recorded contents of the IC card can be edited.
[0086]
On the operation screen 73, a list display 73A of recorded route search results, a selection mark 73B, a data amount display 73C of a new search result, a savable / unavailable display 73D, and a savable capacity display 73E are displayed. On the other hand, the operation panel 74 includes cursor movement switches 74A and 74B, a selection confirmation switch 74C, a save switch 74D, and a delete switch 74E.
[0087]
When the operator saves a search result at random (irregular type) on the SRAM 72 of the IC card, (1) If the memory has a free area 72B enough to hold a new route search result, the free area 72B Holds the new route search result. In this case, the savable / non-savable display 73D on the display screen 73 is displayed as savable, and the recording is executed immediately when the operator operates the save switch 74D.
[0088]
However, (2) when the SRAM 72 does not have a free area 72B enough to hold a new route search result, the size and free space of the result that is specified by the operator to be deleted among the results recorded in the past are determined. The added numerical value is output to the storage capacity display 73E. This is defined as size A. Also, the numerical value of the size of the new route search result is output to the data amount display 73C of the new search result. This is defined as size B.
[0089]
Further, the size relationship between the sizes A and B is checked and output to the savable / non-savable display 73D. Whether it can be held or not is determined by “size A ≦ size B”. If this relationship is established, the display indicates that storage is possible.
[0090]
The designation of deletion by the operator is performed by the operator moving the cursor movement switches 73A and 73B and operating the selection confirmation switch 74C based on the list display 73A on the display screen 73. A selection mark 73B is output for the designated route search result. A value obtained by adding the capacity of the designated route search result (or a plurality of route search results) to the capacity of the free area 72B is output to the capacity display 73E. If the operator operates the save switch 74D at the stage where the save possibility is displayed on the save enable / disable display 73D, the designated route search result is immediately erased, and the remaining route search results are recorded in the SRAM 72 with the head of the route searched. The new route search result is recorded in the formed free space.
[0091]
The procedure for updating (replacing) the result is as follows. (1) Delete the data specified by the operator. (2) Move (memory copy) the resulting area so as to fill the deleted area. This is to secure a continuous free area. (3) Record a new result in the free area.
[0092]
By the way, if there is no free space 72B in the SRAM 72 just to hold the new route search result, the combination of the route search results satisfying the relationship of “size A ≦ size B” is displayed on the display screen without waiting for the operator's designation operation. 73 may be displayed.
[0093]
The following method can be adopted as a method of selecting the route search results that are included in the erasure recommendation list. (1) If it is possible to record a new route search result only by erasing one route search result, select that one route search result. (2) If a new route search result cannot be recorded unless a plurality of route search results are deleted, a combination that minimizes the number of route search results to be deleted and minimizes the total size is selected. (3) Select in order from the oldest route search results. These automatic selection functions may be arbitrarily selectable by the operator.
[0094]
【The invention's effect】
According to the route search device of the first aspect, since the place name of the end point is displayed, setting of the end point can be confirmed.
[0095]
In the route search device according to the second aspect, since the place name of the start point is also displayed, the setting of the start point can be confirmed.
[0096]
In the route search device according to the third aspect, the place name existing near the end point is detected and displayed, so that it is easy to confirm the setting of the end point.
[0097]
In the route search device according to the fourth aspect, the place name based on the link statute existing near the end point is detected and displayed, so that it is easy to confirm the setting of the end point.
[0098]
In the route search device according to the fifth aspect, since the place name existing near the start point is detected and displayed, it is easy to confirm the setting of the start point.
[0099]
In the route search device according to the sixth aspect, since the place name based on the link law existing near the start point is detected and displayed, it is easy to confirm the setting of the start point.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a route search device according to an embodiment.
FIG. 2 is an explanatory diagram of a processing program.
FIG. 3 is an explanatory diagram of display contents.
FIG. 4 is an explanatory diagram of a point setting function.
FIG. 5 is an explanatory diagram of creation of parent-child relationship data of a node;
FIG. 6 is an explanatory diagram of a hierarchical route search.
FIG. 7 is an explanatory diagram of a hierarchical route search result.
FIG. 8 is an explanatory diagram of a map cutout method in a search.
FIG. 9 is an explanatory diagram of a function of saving and updating search results.
[Explanation of symbols]
11 Input section
12. Route data storage unit (third storage unit)
13 Map database (first storage means)
14 Position sensor
15 memory (second storage means)
16 processing unit (calculation means etc.)
17 Display
17A bar graph (first display means)
17B bar graph (second display means)

Claims (6)

In a route search device that searches for a traveling route between the set start point and end point and performs route guidance based on the searched route,
An end point name display means for displaying a place name of the set end point during the route search. The route search device according to claim 1,
A route search device comprising: a start point name display unit that displays a place name of the set start point during the route search. In the route search device according to claim 1 or 2,
The route search device, wherein the place name of the end point is a place name given to a point near the end point searched based on the end point. 4. The route search device according to claim 3, wherein the end point name display means calculates a place name from node information of a neighboring node of the end point searched based on the set point. The route search device according to claim 2,
The route search device, wherein the place name of the start point is a place name given to a point near the start point searched based on the start point. 6. The route search device according to claim 5, wherein the start point name display means calculates a place name from node information of a neighboring node of the start point searched based on the set point.

Images