JP4502766B2 - Route search device - Google Patents

Description

  The present invention relates to a route search device, and more particularly to an in-vehicle navigation device.

  In Patent Document 1, the information stored in its own storage device is used to search for the best route for each of a plurality of condition items such as distance, time, and cost, and the route and the feature amount (conditions) of each route. A car navigation device that displays a route length when the item is “distance”, a required time when it is “time”, and a toll if it is “cost” on the display is described. The user selects a desired route from the displayed routes.

JP 2003-214879 A

  However, since the technology described in Patent Document 1 does not consider the current traffic situation, a route that can actually travel smoothly is not always searched.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for searching for a route that can actually travel more smoothly.

  In order to solve the above problems, the route search apparatus of the present invention performs route search using the link cost calculated using the current traffic information.

For example, the route search device of the present invention includes an information acquisition unit that acquires traffic information from a center that distributes current traffic information, a speed threshold reception unit that receives an input of a speed threshold, and a current status acquired by the information acquisition unit. A link cost calculating means for obtaining a link cost using traffic information and the speed threshold; a route searching means for searching for a route using the link cost calculated by the link cost calculating means; and a smaller traveling speed. Means for storing traffic jam level information including the traffic jam levels associated with each other. Then, the link cost calculation means corrects the traffic congestion level information so that the traffic congestion level of the traveling speed greater than the speed threshold is the minimum level, and then uses the corrected traffic congestion level information to calculate the link cost. The route search means calculates and searches for a route having the minimum total cost using the link cost calculated by the link cost calculation means .

  Further, the route search device of the present invention includes a means for storing map information and fuel consumption information, an information obtaining means for obtaining traffic information from a center that distributes the current traffic information, and a current status obtained by the information obtaining means. A link cost calculating unit that obtains a link cost using traffic information, the map information, and the fuel consumption information; and a route searching unit that searches for a route using the link cost calculated by the link cost calculating unit.

  The route search apparatus of the present invention receives means for setting search conditions, route search means for searching for a standard route according to the search conditions, display means for displaying the standard route, and instructions for correcting the standard route. You may have a route correction reception means. The route searching means further searches for a corrected route according to the correction instruction received by the route correction receiving means, and the display means displays the standard route and the corrected route, and also displays the standard route and the corrected route. Comparison information for comparing the route may be displayed.

  FIG. 1 is a schematic configuration diagram of a navigation system to which an embodiment of the present invention is applied. The navigation system according to the present embodiment collects the car navigation device 101 mounted on the vehicle, the information providing center 106 that provides the car navigation device 101 with various data such as point information and traffic information, and the nationwide traffic information. The traffic information center 107 provides traffic information to the information providing center 106 connected by the dedicated line 108. The car navigation apparatus 101 is connected to a mobile phone 102, and communicates with the information providing center 106 from the mobile phone 102 via the wireless base station 104 and the network 105. In addition, the car navigation apparatus 101 is configured to be able to connect various sensors mounted on a vehicle such as a GPS receiver 103 and a vehicle speed sensor and a gyro sensor (not shown). The traffic information center 107 can be realized by a known computer system.

  FIG. 2 is a schematic configuration diagram of the information providing center 106. The information providing center 106 includes a CPU 401, a memory 402, an external storage device 403 such as a hard disk device, a reading device 409 that reads data from a portable storage medium 410 such as a CD-ROM or a DVD-ROM, a keyboard, An input device 407 such as a mouse, an output device 408 such as a monitor, a communication device 1 (405) communicating with the traffic information center 107, a communication device 2 (406) communicating via the network 105, and each of these devices And a bus 404 for connecting the two. The information providing center 106 may include a plurality of computer systems having such a configuration. Each computer system can be constructed on a distributed network system configured by connecting each computer system using a network interface (not shown).

  FIG. 3 is a functional block diagram of the information providing center 106. The information providing center 106 includes a communication unit 301, a request receiving unit 302, a providing unit 303, a traffic information processing unit 307, a traffic information acquisition unit 308, a map information DB 310, a point information DB 311, and a predicted traffic information DB 313. And a traffic information DB 312.

  The communication unit 301 communicates with the car navigation device 101 connected via the network 105. The request reception unit 302 receives a request from the car navigation device 101 connected via the communication unit 301 and transmits the request to the provision unit 303.

  The providing unit 303 provides information corresponding to the request transmitted from the car navigation device 101 by communication to the car navigation device 101 via the communication unit 301. The providing unit 303 includes a map providing unit 304, a POI (Point of Interest) search unit 305, and a traffic information providing unit 306.

  When map data is requested from the car navigation apparatus 101, the map providing unit 304 calls map data of a predetermined area including the position of the point designated at the time of request from the map information DB 310. And after storing as a file, it provides to the car navigation apparatus 101. Note that the map information stored in the map information DB 310 can have the same configuration as the map information 220 held by the car navigation device 101 described later.

  When the point information is requested, the POI search unit 305 searches the point information DB 311 for the corresponding POI (point information) based on the genre, telephone number, point name, address, etc. specified from the car navigation device 101 at the time of the request. To do. The information is stored as a file and then provided to the car navigation apparatus 101.

  When traffic information is requested from the car navigation device 101, the traffic information providing unit 306 accesses the predicted traffic information DB 313 or the traffic information DB 312 via the traffic information processing unit 307 and searches for the requested information. Then, once stored as a file, it is provided to the car navigation apparatus 101.

  FIG. 4 shows a configuration example of traffic information provided (downloaded) to the car navigation device 101 by the traffic information providing unit 306. The traffic information to be downloaded includes traffic jam / travel time information 1030, accident / regulation information 10640, and the like.

  The traffic jam / travel time information 1030 is information used for route search. The traffic jam / travel time information 1030 includes a representative traffic jam status 1032, a link travel time 1033, a section number 1034, and section information 1035 for each link ID 1031 of each link.

  The link ID 1031 is a unique number for uniquely identifying the target link, and corresponds to the map information link ID in the map information DB 310. The representative traffic jam status 1032 is traffic jam information indicating the traffic jam status of the entire target link, and is indicated by three levels: traffic jam, congestion, and smooth traffic. The link travel time 1033 is information indicating the time required to travel from the end to the start of the target link. The number of sections 1034 is the number of sections in the link. The section information 1035 is information indicating a traffic jam situation in a detailed section in the target link. The section information 1035 includes a section head position 1037 for specifying a section, a section length 1038, and a traffic jam situation 1036 in the section.

  FIG. 5A is a diagram illustrating a specific configuration example of the traffic jam / travel time information 1030. FIG. 5B is a diagram showing the state of the link in the example. That is, when the traffic jam / travel time information 1030 of the link whose link ID 1031 is “1” is configured as shown in FIG. 5A, it can be seen from the number of sections 1034 that this link consists of three sections. From the information on the traffic jam 1036, the head position 1037, and the section length 1038, the section 1 is a smooth section of 200 m, the section 2 is a congested section of 110 m, and the section 3 is a congested section of 190 m. I understand. Note that. In the example of FIG. 5, the number of sections is 3, but it can be expressed by an arbitrary number of sections according to the state of traffic jam in the link.

  The accident / regulation information 1040 includes point information 1042, a link ID 1043, and an accident / regulation type 1044.

Returning to FIG. The traffic information acquisition unit 308 periodically downloads the latest traffic information from the traffic information center 107 connected via the dedicated line 108 and stores it in the traffic information DB 312. The traffic information processing unit 307 uses the traffic information accumulated in the traffic information DB 312 to predict a traffic situation several minutes, hours, or days ahead, and stores the predicted information in the predicted traffic information DB 313. The traffic information processing unit 307 predicts near-future traffic conditions using, for example, the following method.
(1) The traffic information stored in the traffic information DB 312 is classified into day types such as weekdays and holidays, and the average value of travel time data or traffic jam data in the same time zone is obtained for each category, and the value is determined as the target time zone. To apply to the predicted value of.
(2) A time series data extrapolation method that obtains a curve (straight line) to be extrapolated from the current time series data by a method such as autoregression, Kalman filter, neural network, etc. and predicts the traffic situation in the near future.
(3) A method of making predictions using data of similar days by comparing the time series data of the past day and the time series data of the current day.

  The traffic information processing unit 307 generates predicted traffic information by predicting a traffic situation several minutes, hours, or days ahead using any of the above methods, and stores the predicted traffic information in the predicted traffic information DB 313.

  FIG. 6 is a schematic configuration diagram of the car navigation apparatus 101. The car navigation apparatus 101 connects the CPU 201, the RAM 202 that functions as a work area of the CPU 201, the flash ROM 203 that stores various programs for realizing each function that can be provided by the car navigation apparatus 101, and the mobile phone 102. Mobile phone IF (interface) 204, HDD (hard disk) 210 for storing various information, sensor IF 206 for connecting various sensors such as GPS receiver 103, vehicle speed sensor, gyro sensor, and operation buttons It includes a group 207, a remote control light receiving unit 205 that receives a signal from the remote controller 110, a display 208, and a bus 209 for connecting them together.

  Information stored in the HDD 210 includes map information 220, traffic congestion level information 222, fuel consumption information 224, traffic information 226, and route information 228.

  The map information 220 stores node data related to intersections and link data related to roads connecting the intersections for each mesh divided into secondary mesh sections. The secondary mesh section is an area about 10 km square, divided into 12 divisions per north latitude and 8 divisions per east longitude. FIG. 7A is a diagram illustrating a configuration example of the node data 2201 stored for each secondary mesh section. The node data includes, for each node record, a node number 2202 that can uniquely identify the node, a latitude and longitude 2203, and a connection link number 2204 related to a link that is connected to the node. FIG. 7B is a diagram illustrating a configuration example of link data. For each link record 2211, the link data includes a link number 2212 that can uniquely identify the link, a link length 2213, a road type 2214 that can determine whether the link is a general road or a highway, a lane number 2215, It includes a regulation speed 2216, a connection node number 2217, a shape 2218, and a gradient 2219 that indicates the slope of the road.

  The map information 220 may be stored in advance in the HDD 210 of the car navigation device 101, or may be downloaded from the information providing center 106 and used.

  The traffic congestion level information 222 is basic data used for calculating a link cost when searching for a smooth route to be described later. The traffic congestion level information 222 is stored separately for general roads, urban highways, and urban highways. As shown in FIG. 8, the traffic congestion level information 222 includes information related to the traffic congestion level C (V) 2221 per unit length for the travelable speed V [km / h]. The traffic congestion level C (V) 2221 per unit length basically becomes smaller as the section that can travel faster. The traffic congestion level C (V) 2221 per unit length is divided into, for example, five levels. A section where the travelable speed V is 10 km / h or less is set to a maximum level of 5, and a section where the travelable speed V is 40 km / h or more is set to a minimum level of 1. In addition, this traffic congestion level does not need to be five steps, and each level value may not be a value limited to the range of 0-5.

  The traffic congestion level information 222 may be stored in advance in the HDD 210 of the car navigation device 101, or may be downloaded from the information providing center 106 and used.

  The fuel consumption information 224 is basic data used for calculating a link cost when searching for a route with less fuel consumption, which will be described later. As shown in FIG. 9, the fuel consumption information 224 includes information related to the fuel consumption with respect to the traveling speed and the road gradient. The fuel consumption included in the fuel consumption information 224 has the following tendency. Looking at the relationship between the traveling speed and the fuel consumption with a constant road gradient, the lower the traveling speed, the worse the fuel efficiency. The higher the traveling speed, the better the fuel efficiency. In addition, when the relationship between road gradient and fuel efficiency is seen with a constant traveling speed, the higher the road gradient (in the positive direction), the higher the slope, the lower the fuel efficiency and the smaller the road gradient (in the negative direction). As it is downhill, fuel efficiency is improved. As described above, since the fuel consumption of the vehicle depends on the travel speed of the vehicle and the road gradient, the fuel consumption information 224 includes the fuel consumption data 2241 corresponding to the travel speed and the road gradient. The fuel consumption information 224 may include an average characteristic of a general vehicle. Further, the fuel consumption characteristics of a vehicle equipped with the car navigation device may be included. Further, the fuel consumption information data 2241 may be stored as a travel distance per liter as shown in FIG. 9, or may be stored as a fuel consumption per unit length.

  The fuel consumption information 224 may be stored in advance in the HDD 210 of the car navigation device 101, or may be downloaded from the information providing center 106 and used.

  The traffic information 226 is information downloaded from the information providing center 106 and includes current traffic information.

  The route information 228 is information regarding the searched route. The route information 228 includes link information, node information, and the like constituting the route.

  FIG. 10 is a functional block diagram of the car navigation apparatus 101. The car navigation apparatus 101 includes an input unit 600, a traffic congestion level correction unit 602, a vehicle position acquisition unit 609, a traffic information acquisition unit 610, a link cost calculation unit 613, a standard route search unit 614, and route comparison information. A generation unit 616, a corrected route search unit 618, a display unit 612, and an information storage unit 605 are included.

  The input unit 600 transmits a user operation signal to the main control unit 601. The input unit 600 includes an operation button group 207, a remote control 110, a remote control light receiving unit 205, and the like.

  The storage unit 605 includes a RAM 202, a flash ROM 203, an HDD 210, and the like. The display unit 612 includes a display 208, and performs display according to instructions from each processing unit.

  The own vehicle position acquisition unit 609 calculates the own vehicle position from a signal obtained by the GPS receiver 103 or a vehicle speed sensor.

  The traffic information acquisition unit 610 downloads traffic information including the current traffic status from the information providing center 106 via the mobile phone 102 or the like periodically or in response to a request from the user. The downloaded traffic information is stored in the storage unit 605.

  The traffic congestion level correction unit 602 corrects the traffic congestion level information 222 stored in the storage unit 605 based on the smooth speed input by the user using the input unit 600.

  The link cost calculation unit 613 includes information on the vehicle position calculated by the vehicle position acquisition unit 609, traffic information received by the traffic information acquisition unit 610, traffic congestion level information 222, fuel consumption information 222, and map information 224. The link cost of each link is calculated based on the destination and search condition information input by the user via the input unit 600.

  Based on the link cost of each link calculated by the link cost calculation unit 613, the standard route search unit 614 uses the Dijkstra method or the like to generate the route with the lowest cost from the vehicle position to the destination (hereinafter, “standard route”). "). In addition, the searched route is displayed on the display unit 612.

  When receiving a correction instruction for the searched route, the correction route search unit 618 searches for a route reflecting the content of the correction instruction (hereinafter referred to as “correction route”). In addition, the searched route is displayed on the display unit 612. The corrected route search unit 618 can receive a route correction instruction any number of times, and searches for a corrected route each time it is received.

  The route comparison information generation unit 616 includes route information (route length and required time, congestion length on the route, fuel consumption amount) of the standard route searched by the standard route search unit 614 and the corrected route searched by the corrected route search unit 618. And the like, and information for making it easier for the user to compare the two routes is generated and displayed on the display unit 612.

  The functions of the above processing units are achieved by the CPU 201 executing a program loaded in the memory 202.

  [Description of Operation] Next, the operation of the car navigation apparatus 101 configured as described above will be described. FIG. 11 is a flowchart showing a process flow of the operation of the car navigation apparatus 101. This flow starts when a route search request is received from the user via the remote controller 110 or the operation button group 207.

  (Step 500) First, the main control unit 601 sets a smoothing speed desired by the user (threshold for smoothing speed). Specifically, the main control unit 601 displays a smooth speed setting screen 900 on the display 208 as shown in FIG. Note that the setting screen 900 may be displayed when a smooth speed setting request is received from the user. On the setting screen 900, the currently set smooth speed is displayed for each of the general road, the city highway, and the intercity highway. The initial values of the smoothing speed are 40 km / h, 60 km / h, and 80 km / h, respectively.

  The main control unit 601 receives these value change requests via the remote controller 110 or the like. Then, the value requested to be changed is displayed on the display 208. When the main control unit 601 receives a request to confirm the change of the smoothing speed from the user, the main control unit 601 sets the smoothing speed with the value specified at that time.

  (Step 505) Next, the traffic level correcting unit 602 corrects the traffic level information 222 stored in the storage unit 605. Specifically, the congestion level information 222 is corrected so that the congestion level per unit length becomes the minimum level at the set smooth speed or higher. For example, in the case where the relationship between the traveling speed and the traffic congestion level is as shown in FIG. 8, when the smooth speed is changed from 40 km / h to 50 km / h, it is as shown in FIG. That is, the traffic congestion level of 40 to 50 km / h is increased by one, and the traffic congestion level per unit length is corrected to 1 which is the minimum only when the traveling speed is 50 km / h or higher. Then, the traffic congestion level correction unit 602 stores the corrected traffic congestion level information 222 in the storage unit 605.

  (Step 510) Next, the main control unit 601 sets search conditions. Specifically, the main control unit 601 first displays a setting screen 905 on the display 208 as shown in FIG. On the screen 905, for example, “Shorten Travel Distance” 906 for searching for the shortest distance route to the destination, “Fast Arrival Time” 907 for searching for the shortest required time route to the destination, and the step 500 are set. Search conditions such as “Many smooth sections” 908 for searching for a route that can stably travel to the destination at a speed equal to or higher than the smooth speed and “Low fuel consumption” 909 that minimizes the fuel consumption are displayed. When the main control unit 601 receives a request for selecting one of the four search conditions via the remote controller 110 or the operation button group 207, the main control unit 601 sets the search condition with the selected contents.

  (Step 520) Next, the link cost calculation unit 613 calculates a link cost so that a standard route satisfying the search condition set in Step 510 is searched. The link cost calculation unit 613 calculates the link cost according to the following (Equation 1).

(Expression 1) Link cost = α1 × link length + α2 × link travel time + α3 × link congestion level + α4 × fuel consumption Here, α1, α2, α3, and α4 are cost coefficients. The link length on the right side of (Expression 1) indicates the length of each link, and “link length” included in the map information 220 of the storage unit 605 is substituted. The link travel time on the right side of (Expression 1) indicates the travel time required for the target link, and “link travel time” included in the traffic information 226 in the storage unit 605 is substituted. The values calculated based on the traffic level information 222 and the fuel consumption information 222 are substituted for the link traffic level and fuel consumption on the right side of (Equation 1), respectively. These will be described later.

  The first to fourth terms on the right side of (Expression 1) correspond to the route search conditions set in step 510. If the first term is emphasized, a route satisfying “short travel distance” is searched, if the second term is emphasized, a route satisfying “fast arrival time” is searched, and if the third term is emphasized, “smooth section” A route satisfying “many” is searched, and if the fourth term is emphasized, a route satisfying “low fuel consumption” is searched. Accordingly, the link cost calculation unit 613 determines the cost coefficient and calculates the link cost so that the weight of the item corresponding to the search condition selected by the user is increased.

  FIG. 14 shows an example of the set value of the cost coefficient when each search condition is selected. For example, when the user selects “short travel distance” 2232 as the search condition 2231, only α 1 is set to 1 and the other coefficients are set to 0. As a result, only the first term on the right side of (Equation 1) remains, so the route with the shortest distance is simply searched. If “faster arrival time” 2233 is selected, only α2 is set to 1 and other coefficients are set to 0. Similarly, when “Large smooth section” 3334 and “Low fuel consumption” 2235 are selected, only α3 and α4 are set to 1, and the others are set to 0.

  Next, a method for calculating the link congestion level on the right side of (Expression 1) will be described with reference to FIG. The link traffic congestion level is obtained using the traffic congestion level information 222 and the traffic information 226. When obtaining the link congestion level of a certain link, the link is first divided into sections 2241 having a minute interval d (for example, 10 m). Then, the traffic jam situation in each minute section 2241 is obtained from the section information 1035 of the traffic information 226. 10 km / h (V = 10) when the traffic condition is “congested”, 20 km / h (V = 20) when the traffic is “congested”, and the link regulation speed (V = regulation speed) when it is “smooth” Suppose you can drive at Then, the traffic congestion level C (V) is obtained from the traffic congestion level information 222, the section traffic congestion level is calculated from C (V) · d, and is accumulated for the entire link to obtain the link traffic congestion level of the link.

  Alternatively, the link congestion level may be obtained as follows. First, an average link speed is obtained from (link length) / (link travel time) from the link travel time of the traffic information 226 and the link length of the map information 220. Assuming that the average speed of this link is the speed V at which the target link can travel, the traffic level C (V) per unit length is read from the traffic level information 222, and the target link's level is calculated from C (V) / link length. Calculate the congestion level. Using any of these methods (Equation 1), the link congestion level on the right side is calculated.

Next, a method for calculating the fuel consumption included in the right side of (Equation 1) will be described. The fuel consumption amount of each link is calculated from the fuel consumption information 224, the traffic information 226, and the map information 220 stored in the storage unit 605. First, gradient information of each link is read from the map information 220. Further, the speed at which each link can travel is obtained by (link length) / (link travel time) from the link travel time of the traffic information 226 and the link length of the map information 220. Then, the fuel consumption is read from the fuel consumption information 224 from the gradient of each link and the traveling speed, and the fuel consumption amount of each link is calculated by the following (Equation 2).
(Formula 2) Fuel consumption = (link length) / (fuel consumption)
As described above, the fuel consumption included in the right side of (Equation 1) can be calculated. In addition, when the fuel consumption information 224 is not the travelable distance per liter but the fuel consumption per unit length, the target is (link length) × (fuel consumption per unit length). It is possible to calculate the fuel consumption at the link.

  (Step 530) When the link cost is obtained as described above, the standard route search unit 614 next searches for the standard route based on the link cost calculated above. The search for the standard route is performed by, for example, a link existing in a quadratic area having a rectangular area with a straight line connecting the vehicle position and the destination as a diagonal line or a circular area having a radius with a straight line connecting the starting point and the destination. Is calculated using the Dijkstra method. According to the Dijkstra method, it is possible to find a route having a minimum accumulated link cost among routes (link train) from a departure point (own vehicle position) to a destination. Then, the standard route search unit 614 stores the result of this route search in the storage unit 605 as route information 228.

  The standard route search unit 614 calculates a standard route distance, a required time, a congestion distance on the route, and a fuel consumption amount (hereinafter collectively referred to as a route feature amount). The distance of the standard route is obtained from the sum of the link lengths of the links constituting the standard route from the vehicle position to the destination. The required time is obtained from the sum of the link travel times for each link. As for the traffic jam distance on the route, based on the zone information of each link, the total length of the zones where the traffic jam degree is “Junk” or the zone where the running speed is less than the smooth speed set in Step 500 Calculated by the total length. This traffic distance may be a traffic congestion ratio in the entire route. In the case of the traffic congestion ratio, the traffic congestion distance / route length is obtained. Further, the fuel consumption is obtained by the sum of the fuel consumption of each link calculated by (Equation 2).

  (Step 540) Next, the standard route searching unit 614 stores these pieces of information as route information 228 in the storage unit 605 and displays them on the display 208. FIG. 16 shows an example of the display screen. In the display screen 910 of FIG. 16, reference numeral 1140 is the vehicle position, reference numeral 1142 is the searched standard route, reference numeral 1144 is the destination, and reference numeral 1130 is information on the standard route.

  Note that, for the traffic jam distance among the feature amounts shown here, the smooth distance may be calculated and displayed. The smooth distance can be calculated by the sum of the lengths of sections that can travel at the smooth speed or higher set in step 500. Further, this smooth distance may be displayed as a smooth ratio. The smoothing rate can be obtained from the smoothing distance / path length.

  (Step 545) Next, the main control unit 601 receives a selection from the user as to whether or not to adopt the standard route as the guidance route. When the user selects the standard route as the guidance route (that is, when the determination button is pressed using the remote controller 110 or the like) (Yes in Step 545), the main control unit 601 performs route guidance using the standard route. Start (step 570).

  (Step 550) When the user is not satisfied with the standard route and the standard route is not selected (No in Step 545), the corrected route searching unit 618 searches for the corrected route.

  Specifically, first, the correction route search unit 618 displays a correction item setting screen 915 as shown in FIG. On the setting screen 915, route correction buttons 1100 to 1114 for correcting the route are displayed. Buttons 1100 and 1102 are correction buttons for correcting the route so that the distance is “short” and “long” with respect to the standard route, respectively. The buttons 1104 and 1106 are buttons for correcting the required time to be “short” and “long”, respectively, with respect to the standard route. Buttons 1108 and 1110 are buttons for correcting the traffic jam distance to be “less” and “more” with respect to the standard route. Buttons 1112 and 1114 are buttons for correcting the fuel consumption amount to “small” and “large”, respectively, with respect to the standard route. When any one of these buttons 1100 to 1114 is pressed by the user via the remote controller 110 or the like, the corrected route search unit 618 searches for a corrected route reflecting the same. The corrected route search unit 618 searches for one corrected route every time the user presses one of the route correction buttons once. Hereinafter, this route is referred to as a corrected route 1, a corrected route 2, a corrected route 3,.

  Here, a process in which the corrected route searching unit 618 searches for the corrected route 1 will be described in detail. First, on the screen 910 on which only the standard route 1142 is displayed, when one of the route correction buttons is pressed once by the user, the link cost calculation unit 613 recognizes which button is pressed. Then, the weights of the first to fourth terms on the right side corresponding to the items of “distance”, “required time”, “congestion”, and “fuel consumption” are changed. This change of weight is realized by adjusting the values of the cost coefficients α1 to α4 in the first term to the fourth term on the right side of (Equation 1). FIG. 17 shows the amount of change in the cost coefficient when each route correction button is selected. The change amount data is stored in the storage unit 605 in advance. Assuming that the initial value of the cost coefficient (that is, the cost coefficient used in the search for the standard route) is {α1, α2, α3, α4}, in the search for the corrected route 1, the cost coefficient shown in FIG. {Α1 + Δα1, α2 + Δα2, α3 + Δα3, α4 + Δα4} in consideration of the change amount 2241 is used. Then, the link cost calculation unit 613 newly calculates the α link cost from (Equation 1). The corrected route search unit 618 performs route search using the link cost calculated in this way. Here, the possible range of the value of each cost coefficient is 0 or more and less than 1, and this corresponds to the case where the cost coefficient does not satisfy 0 ≦ αi + Δαi ≦ 1 (i = 1, 2, 3, 4). The route correction button may not be pressed or may not function even if pressed.

  (Step 560) When the corrected route is searched as described above, the route comparison information generating unit 616 generates comparison information for comparing the standard route and the corrected route 1 and displays the comparison information on the screen. Here, the comparison information is information indicating a feature amount of each route of the standard route and the modified route 1, that is, a distance, a required time, a congestion length on the route, and a difference in fuel consumption. A display example of the correction path 1 and the comparison information is shown in FIG. In FIG. 18, the elements having the same reference numerals as those in FIG. 16 mean the same elements. A path 1152 in FIG. 18 indicates the corrected path 1, and a reference numeral 1154 indicates comparison information of both paths. The numerical value of each item in the comparison information denoted by reference numeral 1154 indicates the amount of increase or decrease from the feature amount of the standard route. That is, in the example of FIG. 18, the corrected route 1 has a distance of −5 km (that is, 20 km) with respect to the standard route, the required time is −5 minutes (that is, 30 minutes), and the traffic congestion on the route is +2 km (that is, 5 km). This indicates that the fuel consumption is +0.6 liters (that is, 3.8 liters). As described above, the user can recognize the superiority or inferiority of the route at a glance by indicating the difference in the characteristic value with respect to the standard route with “+” and “−” as comparison information.

  Next, the second and subsequent correction processing when the user further presses the route correction button on the screen of FIG. 18 will be described. The second and subsequent correction processing is basically performed in the same manner as the first time. When the user presses one of the route correction buttons to request a search for the correction route 2, the link cost calculation unit 613 uses {α1 ′, α2 ′, α3 ′ as the cost coefficient used for the search for the correction route 1. , Α4 ′}, the cost cost used for searching the correction path 2 is {α1 ′ + Δα1, α2 ′ + Δα2, α3 ′ + Δα3, α4 ′ + Δα4}, and the link cost is calculated. Then, the corrected route search unit 618 performs route search using the link cost calculated in this way.

  Note that the amounts of change of Δα1, Δα2, Δα3, and Δα4 are the values shown in FIG. Then, the route comparison information generating unit 616 generates comparison information between the standard route and the corrected route 2 in the same manner as in the case of the corrected route 1 and displays it on the screen.

  An example of the screen display of the correction path 2 is shown in FIG. Here, the information of the corrected route 1 is stored in the route information 228 of the information storage unit 605, but is not displayed on the screen. That is, information on only the corrected route 2 and the standard route is displayed on the screen. Since the third and subsequent steps are the same procedure as the second correction, description thereof is omitted.

  Next, the flow of changing the cost coefficient from the search for the standard route to the search for the corrected route will be described with a specific example. First, when searching for a standard route, it is assumed that the user selects “many smooth sections” on the route search condition selection screen 905 in FIG. 13. In this case, as shown in FIG. 14, the cost coefficients are {α1, α2, α3, α4} = {0, 0, 1, 0}. The link cost calculation unit 613 uses this to calculate the link cost from (Equation 1). Then, the standard route search unit 614 searches for a standard route using this link cost. Then, in the screen of FIG. 16 displaying only the standard route, when the user selects “short” of the required time once, {α1, α2, α3, α4} taking into account the change amount of FIG. = {0, 0.2, 1, 0}, the link cost calculation unit 613 calculates the link cost from (Equation 1). Then, the corrected route search unit 618 searches for the corrected route 1. Further, when the user wants to consider the fuel consumption amount and selects “low” in the fuel consumption amount, the link cost calculation unit 613 takes into account the change amount in FIG. 17 and the link cost calculation unit 613 {α1, α2, α3, α4} = {0, 0.2, 1, 0.2} and the link cost is calculated from (Equation 1). Then, the corrected route search unit 618 searches for the corrected route 2. Similarly for the third and subsequent times, the route search is performed with the corrected route 3, the corrected route 4,...

  Next, processing when the route list display button 1170 is pressed on the screen of FIG. 19 will be described. When the route list display button 1170 is pressed by the user, the main control unit 605 reads the route information 228 stored in the storage unit 605 and creates a list of corrected routes searched so far, as shown in FIG. Display on the screen. A list 941 displayed on the right side of the screen 940 in FIG. 20 is comparison information of each correction path. When any one comparison information is selected by the user via the remote controller 110 or the operation button group 207, the main control unit 605 displays a correction path corresponding to the comparison information on the screen. When the selection determination button is pressed, the main control unit 605 starts guidance to the destination through the selected route (step 570).

  The embodiment of the present invention has been described above.

  According to the car navigation device of the above embodiment, the latest traffic information is obtained from the center that distributes the traffic information, and the link cost is obtained based on the current traffic situation. Then, a route search is performed using the obtained link cost. Therefore, a route search is performed in consideration of actual traffic conditions. That is, a route that can actually travel more smoothly is searched.

  Further, according to the car navigation apparatus of the above-described embodiment, the congestion level information 222 stored in the HDD 210 is corrected using the smooth speed information input by the user. Then, the link cost is calculated using this traffic level information 222, and this link cost is used for route search. Therefore, it is possible to search for a route that can stably travel to the destination at a speed equal to or higher than the smooth speed input by the user, and to search for a route as the user likes.

  Further, according to the car navigation apparatus of the above embodiment, the fuel consumption information 222 stored in the HDD 210, the traffic information 226 received from the information providing center 106, and the gradient information of each link included in the map information 220 are displayed. The fuel consumption amount of each link is estimated, and the standard route search unit 614 searches for a route using the fuel consumption amount as a link cost. Therefore, a route with the minimum fuel consumption can be provided, and a route according to the user's preference can be searched.

  Further, according to the car navigation device of the above-described embodiment, the standard route, the correction route, and the comparison information indicating the difference in the feature amount between the standard route and the correction route are displayed on the display unit 612. Therefore, the user can easily perform route comparison and can find a route satisfying the preference by repeatedly inputting a route correction instruction.

  Each process performed by the car navigation device described above may be performed by a server such as an information providing center. Then, the car navigation device may obtain and display information processed by the server.

  The above-described embodiment can be variously modified within the scope of the gist of the present invention. For example, in the above description, an example in which the present invention is applied to a car navigation device has been described. However, the present invention can also be applied to a navigation device other than a vehicle-mounted navigation device.

FIG. 1 is a schematic configuration diagram of a car navigation system to which an embodiment of the present invention is applied. FIG. 2 is a schematic configuration diagram of the information providing center. FIG. 3 is a functional block diagram of the information providing center. FIG. 4 is a diagram illustrating a configuration example of information downloaded from the information providing center to the navigation device. FIG. 5 is a diagram for explaining traffic jam / travel time information. FIG. 6 is a schematic configuration diagram of the car navigation apparatus. FIG. 7A is a diagram illustrating a configuration example of node data included in map information, and FIG. 7B is a diagram illustrating a configuration example of link data. FIG. 8 is an example of a data graph showing the congestion level information. FIG. 9 is an example of a data graph showing fuel consumption information. FIG. 10 is a functional block diagram of the car navigation apparatus. FIG. 11 is a flowchart showing processing of the operation of the car navigation device. FIG. 12A is a display example of a smooth speed setting screen, and FIG. 12B is a display example of a search condition setting screen. FIG. 13 is a diagram for explaining a method for correcting a traffic jam level. FIG. 14 is a diagram illustrating an example of the cost coefficient setting value when each search condition is selected. FIG. 15 is a diagram for explaining a method for calculating a traffic jam level. FIG. 16 is a display example of the standard route on the display screen. FIG. 17 is an example of the amount of change in the cost coefficient when the route correction button is pressed. FIG. 18 is a display example of the correction path 1 on the display screen. FIG. 19 is a display example of the correction path 2 on the display screen. FIG. 20 is a display example of the display screen when the route list display button is pressed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Car navigation apparatus, 102 ... Mobile phone, 103 ... GPS receiver, 104 ... Base station, 105 ... Network, 106 ... Information provision center, 107 ... Traffic information Center, 108 ... dedicated line, 110 ... remote control, 201 ... CPU, 202 ... RAM, 203 ... flash ROM, 204 ... mobile phone IF, 205 ... remote control light receiving unit, 206 ... Sensor IF, 207 ... Operation buttons, 208 ... Display, 209 ... Bus, 210 ... HDD, 220 ... Map information, 222 ... Congestion level information, 224 ..Fuel consumption information, 226 ... traffic information, 228 ... route information, 301 ... communication unit, 302 ... request accepting unit, 303 ... providing unit, 304 ... map proposal 305 ... POI search unit 306 ... Traffic information providing unit 307 ... Traffic information processing unit 308 ... Traffic information acquisition unit 310 ... Map information DB 311 ... Point Information DB, 312 ... Traffic information DB, 313 ... Predictive traffic information DB, 401 ... CPU, 402 ... Memory, 403 ... External storage device, 404 ... Bus, 405 ... Communication device 1 406 Communication device 2 407 Input device 408 Output device 409 Reading device 410 Storage medium 600 Input unit 602・ Congestion level correction unit, 605... Storage unit, 609... Own vehicle position acquisition unit, 610... Traffic information acquisition unit, 612... Display unit, 613. ..Standard route search unit, 616 ... route Compare information generation unit, 618 ... Modify the route search unit

Claims (4)

In the route search device,
Information acquisition means for acquiring traffic information from a center that distributes current traffic information;
A speed threshold receiving means for receiving an input of a speed threshold;
A link cost calculating means for obtaining a link cost using the current traffic information obtained by the information obtaining means and the speed threshold;
Route search means for searching for a route using the link cost calculated by the link cost calculation means;
Means for storing traffic level information including the traffic level associated with the traffic speed so as to decrease as the traveling speed increases.
The link cost calculation means
After correcting the traffic level information so that the traffic level of the traveling speed greater than the speed threshold becomes the minimum level, the link cost is calculated using the corrected traffic level information,
The route search means searches for a route having a minimum total cost using the link cost calculated by the link cost calculation means.
Route search device characterized by having the. The claim 1, further comprising:
Using the current traffic information obtained by the information obtaining means, having a traveling speed estimating means for obtaining an estimated traveling speed of each link;
The link cost calculation means
A route search device characterized by weighting link costs so that a link having the estimated traveling speed larger than the speed threshold is easily adopted in the route. In claim 2,
The travel speed estimating means includes
A route search device characterized in that an estimated travel speed of each link is obtained using a traffic congestion level included in the current traffic information and a travel speed predetermined according to the traffic congestion level. In any one of Claims 1-3 , Furthermore,
A route search apparatus, comprising: a display unit configured to display information related to a length of a section that can travel below the speed threshold or above the speed threshold in the route searched by the route search unit.

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