KR100868789B1 - System for route searching of car and method thereof - Google Patents

Abstract

The present invention relates to a system and method for searching a route of a vehicle by using a map and traffic information. The present invention relates to a region of an optimal reverse route for receiving a starting point and a destination, reading the map and traffic information, and going from a starting point to a destination. Search using the restriction technique. Then, at the time of the route search, the cost from the destination to the predetermined link is periodically stored, and when the vehicle leaves the route, the route from the current position to the destination is calculated, but the time required from the destination to the predetermined link and the current The time required for each route is calculated by summing the costs from the location to the corresponding link to search for and display the optimal route to the destination. In this way, it is possible to know the exact cost to the destination by applying the ideal value that is applied to the area limiting method as the actual value, so that the route search is considered considering only the optimal links, thereby improving the search speed and providing the most accurate optimal route. can do.

Route, navigation, navigation, map

Description

System for route searching of car and method

1 is a view illustrating a path search method in the case of searching a path in the same manner as the initial search in the conventional re-search.

FIG. 2 is a diagram illustrating another conventional route searching method using a conventional route when re-searching.

3 is a block diagram of a route search system for a vehicle according to an exemplary embodiment of the present invention.

4 is a diagram illustrating a simulation network for explaining a route search cost.

5 is a diagram illustrating cost information of a link and a link between forward and reverse links.

6 is a diagram illustrating a priority search screen for explaining the A * algorithm.

7 is a view showing a path searching method of a vehicle according to an embodiment of the present invention.

8 is a view comparing the route search time according to the prior art and the embodiment of the present invention.

9 is a view comparing the searched path in the prior art and the embodiment of the present invention.

The present invention relates to a route search system and method of a vehicle. In particular, the route search by recycling the factors that were initially considered during the route search for the route re-search that may occur when driving between the starting point and the destination requested by the customer, The speed of processing and the accuracy of the route can be guaranteed to provide the operator with more accurate and faster service.

In the case of general route search that is currently being serviced, since it is not a method of separately storing the factors considered for the initial route search, the search speed is the same as the initial search when searching again.

In addition, even if it is not a new way of searching again, the existing route itself is stored and the same route is created at a certain time, and thus the accuracy of the route is reduced.

This conventional path search method will be described with reference to the drawings.

1 is a view illustrating a path search method in the case of searching a path in the same manner as the initial search in the conventional re-search.

Referring to FIG. 1, conventionally, after a starting point / destination is selected (S101), a map and traffic information are loaded (S102), and a route is searched (S103).

When the route is searched, the road guide data is generated (S104), and the road guidance is started (S105).

During the road guidance, it is determined whether the route is off (S106). If the route is off, it is returned to the first step (S101), and the route is searched again.

The conventional path search method has a disadvantage in that it does not reuse any factors or paths that have been previously considered since the same way of initial search is performed even during re-search. Therefore, even in re-search, the improvement of the path search speed cannot be expected.

2 illustrates another conventional path searching method, in which an existing path is used when re-searching.

Referring to FIG. 2, the path search steps S101 to 107 are the same as the above-described method, and the additional steps are the path search S103 and the path departure after S106.

After the path search (S103), the path is stored (S201).

If the vehicle leaves the path afterwards, the stored path is loaded (S202) and the distance element is loaded (S203). In other words, the distance from the rescan point to the path is measured.

Then, after removing the link at a distance within a predetermined distance element (S204), the map and traffic information are loaded (S205).

Next, the route is searched up to the link which has not been removed (S206), and the route path data is generated by connecting the searched route and the route not previously removed (S207).

Then, restart the road guidance (S209), depending on whether the path deviation (S210)

After performing the corresponding step, the route is terminated when arriving at the destination (S211).

Since the path search method utilizes a path that has been previously searched, only a partial section is searched again, so that the path search speed is improved over the prior art described above.

However, since the path search method recycles the existing path, the path generated through the information used in the initial search is maintained as it is, and thus, the path search cannot be reflected when the path is changed due to the changed information at the time of the search. Therefore, the time required information to the destination may be updated, but the change of the route cannot be expected because it cannot be reflected.

The technical problem to be solved by the present invention is to solve the conventional problems, faster and more accurate re-navigation in the navigation (CNS) service reflecting telematics (Delematics) or DMB traffic information, and in the case of long-distance route Due to the processing speed, it is possible to improve the service quality (especially for low-end terminals), and to improve the accuracy by using the latest information at the time of re-search even when reflecting new traffic information during re-search. To provide.

The route search system according to an aspect of the present invention for solving this problem,

Traffic information receiving unit for receiving traffic information from the outside;

GPS receiver for calculating its position;

A cost information storage unit for storing time information for each link in the forward and reverse paths from the source to the destination;

A search distance storage unit for storing time from a destination to a predetermined link from a starting point;

A map information storage unit for storing map information;

An input unit for receiving a starting point and a destination;

The time information is updated with reference to the traffic information, the optimal route is set from the destination to the departure point using the traffic information, the location information, and the time information, the route is guided, and when the vehicle leaves the route, Computing a route from a location to a destination, calculating a time required by adding a time from a destination stored in the search distance storage unit with a time from a current link to the corresponding link, and searching for an optimal path to a destination. A route search engine unit;

And a display unit for displaying the route calculated by the route search engine on a map.

The route search method according to an aspect of the present invention for solving this problem,

As a method of searching for a route of a vehicle using a map and traffic information,

Receiving a starting point and a destination;

Reading the map and the traffic information and searching for an optimal reverse path for moving from a starting point to a destination using an area limiting technique;

Periodically storing the time required from the destination to the predetermined link during the path search;

When the vehicle deviates from the route, the route is calculated from the current location to the destination, and the required time of each route is calculated by adding the required time from the destination to the predetermined link and the required time from the current location to the corresponding link to the destination. Searching for an optimal path of;

Providing a searched optimal path.

A recording medium storing a path search method according to an aspect of the present invention for solving this problem,

A recording medium storing a method of searching a vehicle route using a map and traffic information.

Receiving a starting point and a destination;

Reading the map and the traffic information from a database and searching for an optimal reverse route using a region limiting technique from a starting point to a destination;

A function of periodically storing a time required from a destination to a predetermined link during a path search;

When the vehicle deviates from the route, the route is calculated from the current location to the destination, and the required time of each route is calculated by adding the required time from the destination to the predetermined link and the required time from the current location to the corresponding link to the destination. A function of searching for an optimal path of;

Stores a program that implements the function to provide the searched optimal path.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

3 is a block diagram of a route search system for a vehicle according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the route search system according to an exemplary embodiment of the present invention includes a traffic information receiver 320, a GPS receiver 310, a route search engine 330, a search distance storage 340, and cost information storage. The unit 350 includes a map information storage unit 360, an input unit 370, and a display unit 380.

The traffic information receiving unit 320 receives traffic information from a server (not shown) that provides external traffic information, and the traffic information may include a timely congestion situation of a vehicle. The GPS receiver 310 receives signals from a plurality of GPS satellites and calculates and outputs its position. The cost information storage unit 350 stores time information for each link in the forward and reverse paths from the starting point to the destination, and also stores time information for passing through various links. Such time information may be updated with reference to traffic information. The search distance storage unit 340 may store the time required from the destination to the predetermined link, and may store the time required from the origin to the predetermined link as needed instead of the reverse path. The map information storage unit 360 stores a national map or predetermined corresponding local map information. The input unit 370 may receive a starting point and a destination from a user, and may receive a variety of selections to provide a corresponding service. The display unit 380 displays the optimal route calculated by the route search engine on a map. The path search engine unit 330 may include a path search unit 331 for actually searching a path and a path guide unit 332 for guiding a path.

The route search unit 331 updates the time information with reference to the traffic information, sets an optimal route from a destination to a departure point using the traffic information, location information and the time information, guides the route, and provides a vehicle. When the route deviates, the route from the starting point to the destination is calculated, and the distance from the actual current point to the destination is calculated by adding the time from the destination to the corresponding link at the destination stored in the search distance storage unit. Calculate. The route guider 332 combines the searched optimal route with a real map and displays it on the display 380 so that a user can find a destination.

In the exemplary embodiment of the present invention, the route search unit 331 may initially search for a route in the direction of a destination (forward direction) or search for a route in the direction of a departure (reverse direction) at a destination, and in the opposite direction when re-searching Do a search. In case of searching again, the reverse search technique is applied. In other words, if the backward path search is initially performed, the forward path search method is applied to the re-search instead of the reverse path search method used in the initial search.

In addition, the embodiment of the present invention applies a region limiting technique when searching for a path in the reverse or forward direction, which is well known in the art as an A * algorithm. If necessary, other similar algorithms or methods may be used to search the path.

The path search unit 331 stores the heuristic factor of the A * algorithm found in the reverse direction when re-searching (when applying the forward direction) during the initial search, and then uses the corresponding value stored during the reverse search. By using the heuristic factor applied during the initial search, it is possible to know the exact time required for links between destinations at the starting point, thereby improving the path search speed by excluding unnecessary links from the path search. Since the search is re-explored using the empirical factor, it can be reflected when the path change is needed due to the updated information.

The cost, which is the time information of each link stored in the cost information storage unit 350, is described as follows.

4 is a diagram illustrating a simulation network for explaining a route search cost.

Referring to FIG. 4, in the forward structure, a link cost of the inbound link is added to a turn cost of the outbound link as a path cost, and the cost is a time. .

Next, in the reverse structure, the link cost of the outgoing link plus the turn cost that has been performed in the inbound link is used as a path cost.

A table storing the reverse and forward costs of each of these links is shown in FIG.

Here, in order to improve understanding, it is assumed that all links are one-way in the direction of the arrow of FIG. 4.

4 is a link ID, and assumes link 1 as a starting point and link 13 as a destination.

In FIG. 5, the unit link cost means a cost required to pass through the link, for example, a road travel time, and a turn cost between the link and the link is a cost required when proceeding from the entry link to the exit link, for example, an intersection. It means the passing time. The path cost is the sum of the unit cost and the turn cost, and is the cost used for path searching. Also, the pass cost is calculated by adding the turn cost to the entry link cost in the forward direction and adding the turn cost to the outgoing link cost in the reverse direction. Here, cost is a meaning corresponding to time.

When the path is calculated using the sample of FIG. 4, the path of the shaded portion of the path cost is searched as the most optimal path. That is, in the forward direction, link 1-> 3-> 7-> 10-> 13, and in the reverse direction, 13-> 10-> 7-> 3-> 1 link.

Here, since the cost application is the same in the forward and reverse directions, the path search results of the two directions are the same.

Hereinafter, the A * algorithm, which is the region limiting technique described above, will be described.

The A * algorithm is an artificial intelligence search method using heuristics and limits the search area to a certain area using the heuristics.

When expressed as an equation, the following Equation 1 is obtained.

F (n) = g (n) + {h (n) Ⅹ (1-α)}
F (n): search priority,

delete

g (n): the actual search distance from the source to link n,

h (n): straight line distance from link n to destination

 α: Heuristic Factor (value to make a reasonable area)

Assuming h * (n) is the actual optimal distance value (ideal value) from link n to the destination, allowing h (n) <= h * (n) to hold for all n is acceptable.

And since h * (n) is not always known exactly, we use estimates h (n) instead of h * (n). We also use the α value for admissibility. Here, the closer h (n) is to h * (n), the better the efficiency.

The A * algorithm and the general priority search are compared with reference to FIG. 6 as follows.

Referring to FIG. 6, since g (a) <g (b) for general priority search, a is searched first, but for search by A * algorithm, f (a) = g (a) + h (a) Since f (b) = g (b) + h (b), f (a)> f (b), we search for b first. Therefore, it is more accurate than general priority search.

In the embodiment of the present invention, the method of applying the A * algorithm of the path search unit 331 is as follows.

In the case of h (n) in the A * algorithm, the h * (n) value, which is an ideal value in the path search, is unknown, and various links are considered in the search. If the h * (n) value is known in the path search process, the path search may be expected considering only the optimal links, and thus the search speed may be improved.

The route search unit 331 stores the g (n) value considered while searching for the reverse path from the destination to the starting point in the search distance storage unit 340 in advance and utilizes it as the h (n) value in the forward search. Accurate path search is possible by utilizing the ideal value of n).

The value of g (n) calculated in the backward search is the ideal value of h * (n) in the forward search because the calculated value is used in the initial search when the h (n) value is used in the forward search.

Hereinafter, a path searching method in an embodiment of the present invention will be described in detail with reference to FIG. 7.

Referring to FIG. 7, after a starting point / destination is input through the input unit 370 (S701), the route search unit 310 receives traffic information from a traffic information receiver, and loads map information from a map information storage unit. (S702) The optimum route from the destination to the departure point is searched (S703). At this time, the path search unit 331 stores the g (n) value considered in the search distance storage unit 340 in advance while searching for the reverse path from the destination to the starting point. Here, the traffic information may use information stored in the cost information storage unit 350. If necessary, the cost information is updated with the traffic information input from the traffic information receiver 320.

When the optimal route is found, the route guide unit 332 generates the road guide data (S704), takes the current location from the GPS receiver 310, displays it on the map, and starts the road guide (S705).

The route guider 332 determines whether the route deviates during the route guidance (S706), and if the route deviates, the route guide 332 re-searches the route search unit 331.

Then, the path search unit 331 retrieves the g (n) values of the corresponding links stored while searching for the reverse path from the destination to the source (S708). Then, the map and traffic information is loaded (S709), and the route is searched according to the A * algorithm, and the route is searched using the g (n) value as the h (n) value in the forward search (S710). In this case, the g (n) value is a pass cost from the destination to the node calculated during the initial search, and this value is utilized, so it is an ideal value of h * (n) in the forward search. That is, since the time information required from the various nodes to the destination is continuously stored at a predetermined time interval, it is an ideal value of accurate h * (n) reflecting the latest traffic information.

With the A * algorithm using these values, the route search unit 331 searches for an optimal route from the current location to the destination (S710), and the route guide unit 332 generates the road guidance data by combining the optimal route with a map. (S711), the current position is displayed on the display unit 380, and the directions are resumed (S712).

Thereafter, if the path deviates, the process returns to the previous step S708 again to repeat the search again.

On the other hand, the route guidance is terminated when the destination arrives without departing the route (S707 and S713).

In the above process, the route departure is repeated, and when re-searching, the optimal route is set in the forward direction between the current location and the destination, and the optimal route is set by referring to the actual link time, thereby providing more accurate traffic information.

In fact, an example of comparing the two prior art and the embodiment of the present invention described above is as follows.

8 is a view comparing the re-search time in the case of searching the path by the same method as the initial search when re-searching the embodiment of the present invention.

Referring to FIG. 8, the difference in the search time when the distance between the starting point (Seoul) and the destination (Busan Metropolitan City Hall) is far is apparent. That is, the rescanning time is 13.08 seconds in the prior art, but 1.5 seconds in the embodiment of the present invention when the route is separated from the Seoul station.

Also, if the distance between the current location and the destination is close, there is no big time difference, but there is a slight difference.

9 is a view comparing the rescanning path of the embodiment of the present invention with the prior art using the existing path when rescanning.

Referring to FIG. 9, in a traffic situation where the route was searched at 10:10 initially, a path for entering Yeongdong Expressway using the Gyeongbu Expressway through Pangyo JC is appropriate, but when re-searching at 10:35, Pangyo JC to Singal JC Because of the congestion, it is reasonable to avoid the Gyeongbu Expressway and use the Yeongdong Expressway after using the national road.

However, if the existing route is used, it does not reflect the change of the route at the point of re-search because it uses the previously searched route.

In contrast, in the present invention, since the time required from the destination or the current location to the corresponding link is periodically updated and stored, the optimal path at the present time can be guided.

The embodiments of the present invention described above are not implemented only through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Implementation may be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, in the embodiment of the present invention, by applying the ideal value applied to the area limiting technique as the actual value, the exact time with the destination can be known and the route search is performed considering only the optimal links. It is also possible to improve and provide the most accurate optimal path.

Claims (8)

GPS receiver for calculating its position; A cost information storage unit for storing time information for each link in the forward and reverse paths from the source to the destination; A search distance storage unit for storing a time required from the destination to a predetermined link in a path from a destination to a departure point; A map information storage unit for storing map information; An input unit for receiving a starting point and a destination; Using the location information and the time information of the GPS receiver to set the optimum route from the destination to the starting point, to guide the route, if the vehicle leaves the route, calculate the route from the current position to the destination, the search distance A path search engine unit for calculating a required time by adding the time required from the destination stored in the storage unit to the predetermined link and the time from the current location to the predetermined link, and searching for an optimal path to the destination; It includes a display unit for displaying on the map the route calculated by the route search engine, The route search engine unit calculates a search priority (required time) according to the following equation and calculates an optimal route, The route search engine unit calculates the actual optimal distance from the current position to the destination by using the g (n) value calculated during the initial search as a value of {h (n) Ⅹ (1-α)} at the time of re-search. Route search system. F (n) = g (n) + {h (n) Ⅹ (1- α)} F (n): search priority, g (n): the actual search distance from the source to link n, h (n): straight line distance from link n to destination  α: Heuristic Factor (value to make a reasonable area) The method of claim 1, The route search engine unit, the route search system for performing a forward search from the current position to the destination at the time of re-search. delete GPS receiver for calculating its position; A cost information storage unit for storing time information for each link in the forward and reverse paths from the source to the destination; A search distance storage unit for storing a time required from the destination to a predetermined link in a path from a destination to a departure point; A map information storage unit for storing map information; An input unit for receiving a starting point and a destination; Using the location information and the time information of the GPS receiver to set the optimum route from the destination to the starting point, to guide the route, if the vehicle leaves the route, calculate the route from the current position to the destination, the search distance A path search engine unit for calculating a required time by adding the time required from the destination stored in the storage unit to the predetermined link and the time from the current location to the predetermined link, and searching for an optimal path to the destination; It includes a display unit for displaying on the map the route calculated by the route search engine, Path search engine unit. Updating the time information, using the location information and the time information to set the optimal route from the destination to the starting point, guide the route, if the vehicle leaves the route, calculate the route from the starting point to the destination, A route search unit for calculating a distance from an actual current time point to a destination by adding the time from a destination to a predetermined link stored in the search distance storage unit and the time from the starting point to the predetermined link; And a route guide unit displaying the optimum route searched by the route search unit on the display unit in combination with the map information. The route search unit calculates a search priority (time required) according to the following equation and calculates an optimal route, The route search unit calculates the actual optimal distance from the current position to the destination by using the g (n) value calculated during the initial search as a value of {h (n) Ⅹ (1-α)} at the time of re-search. Route search system. F (n) = g (n) + {h (n) Ⅹ (1- α)} F (n): search priority, g (n): the actual search distance from the source to link n, h (n): straight line distance from link n to destination  α: Heuristic Factor (value to make a reasonable area) The method of claim 4, wherein The route search unit is a route search system for performing a forward search from the current position to the destination at the time of re-search. As a method of searching for a vehicle route using a map, Receiving a starting point and a destination; Reading the map and searching for an optimal reverse path from a starting point to a destination using an area limiting technique; Periodically storing costs from a destination to a predetermined link during path search; When the vehicle deviates from the route, the route from the current position to the destination is calculated, and the cost of each route is calculated by summing the time required from the destination to the predetermined link and the cost from the current position to the predetermined link to optimize the destination. Searching for a route; Providing a searched optimal route, Computing the required time of each route by summing the required time from the destination to the predetermined link and the current time from the current location to the predetermined link, and searching for the optimal route to the destination, The search priority (time required) and the optimal route are calculated according to the following equation, and the g (n) value calculated during the initial search is changed to the value {h (n) Ⅹ (1-α)} at the time of re-search. The route search method of a vehicle, characterized in that to calculate the optimum distance from the current location to the destination. F (n) = g (n) + {h (n) Ⅹ (1- α)} F (n): search priority, g (n): the actual search distance from the source to link n, h (n): straight line distance from link n to destination  α: Heuristic Factor (value to make a reasonable area) delete A recording medium storing a method of searching a vehicle route using a map. Receiving a starting point and a destination; Reading the map from a database and searching for an optimal reverse path from a starting point to a destination using an area limiting technique; A function of periodically storing a time required from a destination to a predetermined link during a path search; When the vehicle deviates from the route, the route is calculated from the current location to the destination, and the required time of each route is calculated by adding the time required from the destination to the predetermined link and the time required from the current location to the predetermined link to the destination. A function of searching for an optimal path of; The ability to provide the best route found is implemented. The function of searching for the optimal route to the destination by calculating the required time of each route by adding the required time from the destination to the predetermined link and the time from the current location to the predetermined link, The search priority (time required) and the optimal route are calculated according to the following equation, and the g (n) value calculated during the initial search is changed to the value {h (n) Ⅹ (1-α)} at the time of re-search. The recording medium storing the program, characterized in that to calculate the optimum distance from the current position to the destination. F (n) = g (n) + {h (n) Ⅹ (1- α)} F (n): search priority, g (n): the actual search distance from the source to link n, h (n): straight line distance from link n to destination  α: Heuristic Factor (value to make a reasonable area)

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