Route searching device

BACKGROUND THE INVENTION

territorially invention

The present invention relates to a method for finding a recommended route to a destination and to calculate an estimated travel time, which for the route is needed, in a navigation apparatus installed in a vehicle, etc. is.

With With respect to a navigation device installed in a vehicle is a method for searching a route was known, which from a departure place to a destination extends, on the basis road map data, and proposal of the searched route such as recommended route for one User.

Such a recommended route search process is carried out by a route is searched (selected will), which requires the lowest cost of available routes between the starting point and the destination in accordance with a method known as "Dijkstra's algorithm" or similar is known. In this method, the total distance of the route is or the required Travel time the route usually selected as "costs" are defined in this procedure.

The estimated Travel time required for the route required (hereinafter referred to merely as "estimated travel time"), is calculated as follows. If a recommended route is determined, the length of each of the roads, which the recommended route builds, weighted by the value of the Type any road equivalent (freeway, public road or the like) to the weighted value such as travel time for each road set, and the estimated travel time is calculated on the basis of the travel times for the roads.

recently a traffic information communication system has been introduced to to provide vehicle users with traffic information about communication, which as VICS is known (the brand of the Foundation for traffic information communication system center).

According to this Traffic information communication system is traffic information, as traffic congestion, traffic regulations, etc., from the center to vehicles over transmitted optical signal fire or electric beacon, which arranged on roads are, or FM multi-sending, whereby the real-time use of traffic information allows in vehicles becomes. In a conventional Navigation device, when traffic regulation information from such a traffic information communication system is received, the contents of which traffic regulation information, the represents, the users in the form of characters, language and ads or drawings on a road map notified.

SUMMARY THE INVENTION

The above described, conventional Method to calculate an estimated travel time, which recommended a Route is needed has the following problem.

The called, the journey time, which for the recommended route required is, on the basis of fixed parameters, such as the length of each Street, the Type any street, so calculated, and therefore, if some streets of recommended route of Traffic jams or affected by traffic regulations, as Way traffic or the like differs, the estimated Travel time, which is calculated in such a way, from the actual Travel time sharply.

therefore it is an object of the present invention, an estimated travel time for a recommended to calculate route, which corresponds more to an actual traffic condition.

These and other objects are achieved according to the invention by a route search device, as indicated the independent Claim 1, a required Traveling time calculation method according to independent claim 2 and a Storage medium according to independent claim . 3

On Route search unit To search for a recommended route to a destination comprising: means Representing for storing map data which road maps; medium for receiving traffic jam information, which congestion places represent, and a travel time required is to pass through a portion in which each of the traffic jam places is arranged over Communication; and travel time calculation means for setting a Travel time represented by the traffic jam information as a effective time to travel the traffic jam section, by the traffic jam information received such, is presented as a calculated time on the basis of the map data as an effective travel time for the other sections 1 is set, calculating the sum of the effective travel times for corresponding portions, between the current position on this, recommended road and a target are located, or a point on the recommended Route for which has an estimated Travel time is calculated, and displays the sum of the effective travel time, which is calculated in such a way as <?page 3?>Travel time, which is required to from the current position to the destination, or to point to the examples of good road to travel for which the estimated travel time is calculated.

According to the above Route search unit is traffic congestion information from a traffic information communication system, such as VICS or the like was added, and the estimated Travel time is under consideration the traffic congestion information calculated. Therefore, when an even Traffic jams or traffic control is carried out, an estimated Travel time will be charged, what the actual traffic conditions equivalent.

SHORT DESCRIPTION THE DRAWINGS

<figref idrefs="S15">1</figref> is a block diagram according to the structure of a navigation device of a embodiment of the present invention;

<figref idrefs="S16">2</figref> is a diagram showing the structure of map data according to the embodiment of the present Invention;

<figref idrefs="S17">3</figref> is is a flow chart showing the flow of the navigation device according to the embodiment of the present invention;

<figref idrefs="S18">4</figref> is a diagram showing how a dynamic journey time calculated is, according to the embodiment the present invention; and

<figref idrefs="S19">5</figref> is a diagram showing an example of display according to the embodiment of the present Invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

A preferred embodiment a route searching device according to the present Invention will be described using a case, in which the present invention to a vehicle-mounted type used by GPS becomes.

<figref idrefs="S15">1</figref> shows the construction of a navigation device according to one embodiment of the present invention.

In <figref idrefs="S15">1</figref> stands numeral <figref>1</figref> For a processor which comprises a micro-processor and a memory, numeral <figref>2</figref> represents a Display device, reference numeral <figref>3</figref> represents a drive device to access a storage medium such as a CD-ROM or the like, in which map data is stored, numeral <figref>4</figref> represents an input device for accepting an instruction defined by a User is inputted, numeral <figref>5</figref> represents a sensor device, which sensor includes a vehicle speed comprises an azimuth sensor, a GPS receiver, etc., and numeral <figref>6</figref> represents a traffic information receiving device for receiving Traffic information from a traffic information communication system, as VICS or similar, as described above.

Here the map data is recorded on a storage medium, such as a CD-ROM or the like, which in the drive device <figref>3</figref> Loading is to be discribed.

As in <figref idrefs="S16">2</figref> shown, the map data include road data <figref>21</figref>. which for every street are provided, and the road data <figref>21</figref> include road information <figref>22</figref> and connection information <figref>23</figref>,

The road information <figref>22</figref> contains a street number <figref>26</figref>. which road the uniquely represents a street name <figref>24</figref>, which one the name of the road represents a street type <figref>27</figref>. which the type of road represents (Toll Road, national highway, prefectural highway), and other attributes <figref>25</figref>Representing other information for the road.

The connection information <figref>23</figref> contains connection data <figref>28</figref>. which represents the information of compounds for each compound provided that forms a road. Here, "connection" a line segment, which is used to approximate the shape and position of a road. The connection data<figref>28</figref> contain a compound number <figref>29</figref>Showing the connection unique, and a time <figref>30</figref>That is required, which value a corresponds, which is proportional to the length of the connection.

Further contain the connection data <figref>28</figref> node information <figref>31</figref>. representing information which a compound described next is, for example, information representing that the node a change a service area of ​​a highway is an intersection or the like.

Further contain the connection data <figref>28</figref> for two nodes on both sides a connection node number <figref>32</figref>Which a node uniquely represents a Knotenkoordinate <figref>35</figref>, Which the position of the node represents, and an adjacent node number list <figref>34</figref>. in which the node numbers are listed from all the nodes, the over the affected nodes Links are connected. Here is the link between compounds necessarily a node by&lt;?page 4?&gt;out. At an intersection, a node is arranged in the center of the intersection, and four connections are connected to the node in the middle. In this case contains the adjacent node list <figref>34</figref> the node in the center the Description of the node numbers of the four nodes at the other ends the four compounds which connected to the affected nodes are.

The node data <figref>28</figref> containing compound shape information <figref>36</figref>. specifying the form of a compound. The link shape information<figref>36</figref> comprises one, or a plurality of Subknotenkoordinaten <figref>37</figref>, If the Number of Subknotenkoordinaten <figref>37</figref> equal to two, is the shape of the joint specified as a figure who receive is by sequentially and linearly a first Knotenkoordinate the compound, a first Subknotenkoordinate, a second Subknotenkoordinate and a second Knotenkoordinate the compound in this order get connected.

With the above structure, the processor calculates <figref>1</figref> the actual Position of the vehicle by referring to a vehicle travel azimuth refers, of the azimuth sensor of the sensor device <figref>5</figref> entered is a vehicle speed from the vehicle speed sensor the sensor device <figref>5</figref> is entered, and mesh map data to which the measured, actual position of the GPS receiver sensor device <figref>5</figref> belongs, and calculates an estimated Route from the current location to the destination on the basis of a target, represented by the input device <figref>4</figref> by a user is entered, and the current position represented by the input device <figref>4</figref> by the user is input, or which is calculated from the input from the sensing device <figref>5</figref>,

Of the processor <figref>1</figref> controls the drive device <figref>3</figref>. the road map data on the basis of the current position, which is calculated in such a way to read out, the travel azimuth of the vehicle and the content of the input device by <figref>5</figref> by the User displays, and displays a map that illustrated is represented by the map data on the display device <figref>2</figref>, The map display is performed, by a map of an area around the current, calculated position is around displayed at a predetermined reduced scale by a map of an area is displayed by the user of the set at a predetermined or indicated reduced scale is, or a map is displayed, which covers an area, from the current position suitable reduced to the target, in a Scale, along with this, recommended route. At this time are marks that the current position and the travel azimuth represent the vehicle shown on the map, while superimposed on the map will.

The Calculation processing of the estimated travel time, which by the processor <figref>1</figref> is carried out, will now be described.

<figref idrefs="S17">3</figref> is a flowchart showing the calculation processing of the estimated travel time.

In this processing, the data connection <figref>28</figref> from Connections to a desired, recommended route checked to calculate points select, which are used to calculate the estimated travel time. When calculating the target points are selected and nodes described be in a node information <figref>31</figref> as intersections, turning points and service areas, or which as transition points between different streets serve on the recommended route, among nodes in a predetermined Range from the current position to a position in the direction of travel are (step <figref>301</figref>).

As next is the estimated Travel time is calculated, the required is to travel to any point calculation (step <figref>302</figref>).

The Calculation of the estimated Travel time required is is carried out as follows.

The called, for every Link on the recommended route between the current position and the goal is the journey time <figref>30</figref> the connection data weighting of each link with a value of the road type of the <figref>27</figref> corresponds, the road information the road data <figref>21</figref>. to which the observed data connection lead, whereby a static, needed Travel time is obtained. At the same time, the connection length of of each compound on the basis of the connection data <figref>28</figref> calculated.

following is a required taken to travel to a traffic jam between the starting point and a traffic jam endpoint to travel, which represents be traffic congestion information that the traffic information receiver <figref>6</figref> receive becomes. represented here the journey time, which on the the traffic information receiver <figref>6</figref> received Traffic congestion information is displayed, the current travel time the required is jam start point between the traffic and the traffic jam ending point, which actually is measured. A dynamic travel time, which is needed for each connection, is calculated from the static journey time, which is required for the Compound via the following equation: <st32:df xmlns:st32="http://lighthouseip.com/">Dynamic Travel Time = M - (M × Y / X) + N</st32:df>

&lt;?page 5?&gt;

Here, as in <figref idrefs="S18">4</figref> shown, X represents the connection length of the connection <figref>400</figref>Represented M the static journey time is calculated for the compound <figref>400</figref>. represents Y the length a portion <figref>401</figref>, In the compound <figref>400</figref> contain is a portion between a traffic jam starting point and the traffic jam ending point, and N represents a journey time of Part <figref>401</figref>, Which is calculated on the basis of the travel time, the above the traffic information receiver <figref>6</figref> receive becomes.

If the value of the dynamic travel time, which is calculated on the above equation is greater than the static journey time by more than a predetermined rate or more (two times or more), it is judged that the reception content the traffic information receiver <figref>6</figref> a may contain errors, and consequently is directly the static journey time used as dynamic travel time.

following is for each calculation point, the sum of the dynamic travel times calculated the for the respective connections between the current position and the calculation points are calculated, and it is as an estimated travel time set, the required is to from the current point for consideration calculation point to to travel. Further, the total connection length is set as the travel distance, which is calculated from the respective connections between the current point and the calculation point from the current point to the destination (step <figref>303</figref>).

following is the sum of the static journey time for the respective compounds calculated from the current position to the destination of the estimated, deducted to travel, and the ratio of the subtraction the estimated Travel time is as jam rate (step <figref>304</figref>).

The Travel time required is to travel to each calculation point, together with the travel distance to the considered calculation point appears, such as shown in <figref idrefs="S19">5</figref>,

In <figref idrefs="S19">5</figref> will the estimated travel time <figref>502</figref> and the travel distance <figref>503</figref> to each Calculation point on both the right and left sides of the name <figref>501</figref> from each of the nearest, intersections and services displayed, represented by the node information <figref>31</figref> represented the node (with the exception of the target), which are selected as calculation points. A street between calculation points is displayed as a line segment <figref>505</figref>. linking the names of the nodes, and the name <figref>504</figref> of the road appears at her side. A line segment<figref>506</figref>, the approximately a traffic jam section represents, of through a traffic jam starting point and an end point of traffic congestion is specified, received the information on the traffic information receiver is displayed with each different color on the line segment <figref>505</figref>, A brand <figref>510</figref>Representing a regulatory content, representing is regulatory information by the traffic information receiver <figref>6</figref> receive is displayed in the vicinity of a regulated space. Further, the estimated travel time <figref>507</figref> and the travel distance <figref>509</figref> to the target and a bar graph the rate of the traffic jam is displayed on the upper side.

In Calculation of the dynamic travel time, which is described above, the static travel time is directly used as dynamic travel time when the dynamic travel time is greater, than the static travel time to a predetermined rate or more. Based on the regulatory information that formation receiver from Verkehrsin <figref>6</figref> Will be received, , the predetermined rate for the dynamic travel time of a traffic jam section, of a Verkehrsstauort contains, which is evaluated, caused by a traffic regulation to be, be set to a value which is larger than the other in Cases. This is because, when a traffic jam by traffic regulation caused, the dynamic travel time may be large, regardless of Reception error of the traffic information receiver <figref>6</figref>,

As described above, according to this embodiment the estimated Travel time considering the Verkehrsstau- and traffic regulation information is calculated, which is taken from a traffic information communication system. Therefore, even when a traffic jam occurs or traffic regulation is carried out, a travel time are calculated, the more the actual traffic conditions equivalent.

In this embodiment , the processor <figref>1</figref> be a computer having a CPU, a memory and a suitable operating system. In this case is any process that by the processor <figref>1</figref> is carried out, implemented by the CPU executing a program in which the procedure for each Process is described. In this case, these programs can the processor<figref>1</figref> by a storage medium to be supplied as a CD-ROM or the like.

As described above, according to the present Invention an estimated Travel time, the more the actual Travel conditions equivalent, are calculated.