JP2007198932A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform flexible guidance while taking an actual driving state into consideration. <P>SOLUTION: The navigation device provided with a function for acquiring the current position is provided with: a basic route search means for performing search for a basic route to the destination; a display means for displaying guidance information on the searched basic route; an auxiliary route search means for performing the search for an auxiliary route branching from an intersection on the basic route ahead of the current position and merging with the basic route at an intersection on the basic route further ahead; and a display decision means for deciding whether to display the auxiliary route. The display decision means decides to display the auxiliary route when it is not a detour so much (for example, the difference in the travel time or the distance between the basic route and the auxiliary route is within a prescribed range and so forth). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  There is an in-vehicle navigation device that searches for a route to a destination and displays guidance information at a predetermined timing so that the vehicle can travel along the searched route. For example, guidance display for instructing a right / left turn is performed in front of an intersection to be turned right / left.

JP-A-8-20265

  However, depending on the road conditions, it may be difficult to change the course suddenly for a right or left turn. Furthermore, even if the vehicle goes straight without turning right or left at the guided intersection, it may return to the original route without making a long turn. Even in such a case, a conventional in-vehicle navigation device provides guidance that must make a right or left turn at an intersection in front of the eyes. In this, guidance is inflexible and it cannot be said that it considers the actual situation of driving.

  An object of the present invention is to provide guidance in consideration of actual driving conditions.

  In order to solve the above-mentioned problem, the navigation device of the present invention, if there is another route that can return to the original route without traveling too much, even if it does not travel according to the originally searched route, indicate.

For example, the present invention is a navigation device having a function of acquiring the current position,
A basic route searching means for searching a basic route to the destination;
Display means for displaying guidance information of the searched basic route;
Auxiliary route search means for searching for an auxiliary route that branches from the intersection on the basic route ahead of the current position and merges with the basic route at a further intersection on the basic route;
Display determination means for determining whether or not to display the auxiliary route. When the display determination unit determines that the auxiliary route should be displayed, the display unit displays the auxiliary route together with the basic route.

The display determination unit can determine whether or not the following condition is satisfied.
a) When the difference between the predicted travel time of the route from the branch point of the basic route to the junction and the predicted travel time of the auxiliary route is within a predetermined range,
b) When the difference between the distance of the basic route from the branch point to the junction with the auxiliary route and the distance of the auxiliary route is within a predetermined range,
c) If the expected arrival time from the current position to the branch point to the auxiliary route is within a predetermined range,
d) If the current location is on a road with more than a certain number of lanes,
e) When the travel lane of the vehicle on which the navigation device is mounted is a lane toward the road of the auxiliary route,
f) The difference between the direction of the road connected to the branch point of the basic route to the auxiliary route and the direction of the road of the auxiliary route connected to the branch point is within a predetermined range.

  An embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an in-vehicle navigation device 100 to which an embodiment of the present invention is applied. As shown in the figure, the in-vehicle navigation device 100 includes an arithmetic processing unit 1, a display 2, a storage device 3, a voice input / output device 4, an input device 5, a wheel speed sensor 6, a geomagnetic sensor 7, A gyro sensor 8, a GPS (Global Positioning System) receiver 9, an FM multiplex broadcast receiver 10, and a beacon receiver 11 are provided.

  The arithmetic processing unit 1 is a central unit that performs various processes. For example, the present location is detected based on information output from the various sensors 6 to 8 and the GPS receiver 9. Further, map data necessary for display is read out from the storage device 3 based on the obtained current location information. Further, the read map data is developed in graphics, and a mark indicating the current location is superimposed on the map data and displayed on the display 2. In addition, the map data stored in the storage device 3 is used to search for an optimum route (recommended route) that connects the starting point (current location) instructed by the user and the destination. Further, the user is guided using the voice input / output device 4 and the display 2.

  The display 2 is a unit that displays graphics information generated by the arithmetic processing unit 1. The display 2 is composed of a CRT, a liquid crystal display, or the like.

  The storage device 3 includes a storage medium such as a CD-ROM, DVD-ROM, HDD, or IC card. This storage medium stores map data. The map data includes, for each mesh that is a partitioned area on the map, link data of each link that configures a road included in the mesh area. The link data includes coordinate information of two nodes (start node and end node) constituting the link, link length information indicating the link length, and the like.

  The FM multiplex broadcast receiver 10 receives rough current traffic information, regulation information, SA / PA (service station / parking) information, parking lot information, weather information, etc. sent from the FM multiplex broadcast station as FM multiplex broadcast signals. To do.

  The beacon receiving device 11 receives current traffic information, regulation information, SA / PA information, parking lot information, and the like sent from the beacon.

  FIG. 2 is a block diagram illustrating a main functional configuration of the arithmetic processing unit 1.

  As illustrated, the arithmetic processing unit 1 includes a user operation analysis unit 41, a route search unit 42, a route guidance unit 43, a current position calculation unit 44, an information storage unit 45, and a display processing unit 46.

  The user operation analysis unit 41 receives a request from the user input to the input device 5, analyzes the request content, and controls each unit of the arithmetic processing unit 1 so that processing corresponding to the request content is executed. To do. For example, when the user requests a search for a recommended route, the display processing unit 45 is requested to display a map on the display 2 in order to set a destination. Further, it requests the route search unit 42 to calculate a route from the current location (departure location) to the destination.

  The current position calculation unit 44 uses distance data and angle data obtained as a result of integrating the distance pulse data S5 measured by the wheel speed sensor 6 and the angular acceleration data S7 measured by the gyro 8, respectively. The current position (X ′, Y ′), which is the position after the vehicle travels, is periodically calculated from the initial position (X, Y). Further, by performing map matching processing using the calculation result, the current location is matched with the road (link) having the highest shape correlation. Further, the current position is corrected periodically using the output of the GPS receiver 9.

  The route search unit 42 uses a Dijkstra method or the like to search for a route that minimizes the cost (for example, distance and travel time) of a route connecting two designated points (for example, the current location and the destination).

  The route guidance unit 43 performs route guidance using the route searched by the route search unit 42. For example, the information on the route is compared with the information on the current location, and the voice input / output device 4 is used to inform the user by voice whether the vehicle should go straight before passing an intersection or the like. Further, the route guiding unit 43 displays the direction to travel on the map displayed on the display 2 and notifies the user of the recommended route.

  The display processing unit 46 receives map data in an area required to be displayed on the display 2 from the storage device 3, and at a specified scale and drawing method, roads, other map components, current location, destination, A map drawing command is generated so as to draw a mark such as an arrow for the recommended route. Then, the generated command is transmitted to the display 2.

  FIG. 3 is a diagram illustrating a hardware configuration example of the arithmetic processing unit 1.

  As illustrated, the arithmetic processing unit 1 has a configuration in which devices are connected by a bus 32. The arithmetic processing unit 1 includes a CPU (Central Processing Unit) 21 that executes various processes such as numerical calculation and control of each device, and a RAM (Random Access Memory) that stores map data, arithmetic data, and the like read from the storage device 3. ) 22, a ROM (Read Only Memory) 23 for storing programs and data, a DMA (Direct Memory Access) 24 for transferring data between the memories and between the memory and each device, and graphics drawing. In addition, a drawing controller 25 that performs display control, a video random access memory (VRAM) 26 that stores graphics image data, a color palette 27 that converts image data into RGB signals, and an A / D that converts analog signals into digital signals. Converter 28 and an SCI (Serial Communication Interface) that converts the serial signal into a parallel signal synchronized with the bus. ace) 29, a PIO (Parallel Input / Output) 30 that puts a parallel signal on the bus in synchronization with the bus, and a counter 31 that integrates the pulse signal.

  [Description of Operation] Next, the operation of the in-vehicle navigation device 100 having the above-described configuration will be described.

  When the in-vehicle navigation device 100 configured as described above receives a destination setting from the user via the input device 5, a route to the destination (referred to as a “basic route”) according to the set search condition. ). Then, route guidance is started so that the vehicle can travel along the searched route. Specifically, a display for instructing a right turn or a left turn is performed before a predetermined distance from the intersection to be turned right or left.

  Furthermore, the in-vehicle navigation device 100 according to the present embodiment displays an auxiliary route separately from the basic route under a predetermined condition at a predetermined timing during such route guidance.

  FIG. 4 is a flowchart showing the flow of auxiliary route display processing.

  The route search unit 43 monitors whether or not the point at which the current position is to turn right or left is approaching. Specifically, is there an intersection that needs to turn right (or turn left) when traveling along the basic route within a predetermined distance (for example, within 1 km) on the basic route where the current position exists? Monitor whether or not. When there is such an intersection, the flow shown in FIG. 4 is started (S101).

  First, the route search unit 42 searches for a route (referred to as “auxiliary route”) that returns to the basic route within a predetermined distance, starting from the intersection (referred to as “branch intersection”) (S102). Specifically, an intersection existing ahead (destination side) from the branch intersection on the basic route and within a predetermined distance (for example, 5 km) from the branch intersection is extracted. Then, the branch intersection is used as a start point, the extracted intersection is used as an end point, and links other than the links constituting the basic route are excluded, and a search for a route between them is attempted.

  When the auxiliary route is not searched (No in S103), the route guiding unit 43 ends the auxiliary route display process. That is, the route guidance unit 43 performs only a guidance display instructing a normal right turn or left turn without displaying the auxiliary route.

  On the other hand, when the auxiliary route is searched (Yes in S103), the route guiding unit 43 determines whether or not the auxiliary route should be displayed (S104). The determination is made according to the following criteria.

1) Difference in predicted travel time The route guiding unit 43 obtains a predicted travel time of a route from a branch intersection of the basic route to a junction intersection. Also, the estimated travel time of the auxiliary route is obtained. When the difference is within a predetermined time (for example, within 10 minutes), it is determined that the auxiliary route should be displayed. When a plurality of auxiliary routes are searched, the route with the shortest travel time is selected and used for determination. In addition, the route guidance unit 43 obtains each predicted travel time using the traffic jam information acquired from FM multiplex broadcasting or a beacon. For example, when the congestion level is ranked as “congestion”, “congestion”, and “smooth”, the travel speed corresponding to each congestion level is set to 50 km / h, 30 km / h, and 5 km / h. And the travel speed of the link which comprises a basic route and an auxiliary route is calculated | required. Further, the link travel time is obtained by dividing the link length of each link by the obtained travel speed. Then, by summing the travel times of the links constituting the route, the predicted travel time of the route from the branch intersection of the basic route to the junction intersection and the predicted travel time of the auxiliary route are obtained.

2) Difference in distance The route guidance unit 43 obtains the distance of the route from the branch intersection of the basic route to the junction intersection and the distance of the auxiliary route, and if the difference is within a predetermined distance (for example, 2 km) It is determined that the route should be displayed. The route search unit 42 obtains the distance of each route by adding up the link lengths that constitute the route. Further, when a plurality of auxiliary routes are searched, the route with the shortest distance is selected and used for determination.

3) Expected arrival time to branch intersection This criterion is used because it is difficult to change lanes when the time to reach a branch is short, and it is better to display an auxiliary route.

  The route guidance unit 43 obtains the expected arrival time to the branch point by dividing the distance from the current position to the branch intersection by the current vehicle speed. When the predicted arrival time is within a predetermined time (for example, 30 seconds), it is determined that the auxiliary route should be displayed.

4) Whether or not the auxiliary route is a road The reason why this reference is used is that it is better to display the auxiliary route because it is easier to drive without making a right or left turn on a road.

The route guiding unit 43 acquires the directions of the link of the basic route before the branch intersection and the link following the auxiliary route from the link data of the map data. Note that the direction of each link may be obtained from the coordinate position of the start node and end node of the link. When the difference is within a predetermined range (for example, 0 to 70 °), it is determined that the auxiliary route should be displayed.
5) Whether the number of lanes is driving on a road with a predetermined number or more. The reason for using this criterion is that when there are many lanes, it may be difficult to change the course toward the basic route. This is because it is better.

The map data stores the number of lanes for each road. The route search unit 42 acquires the number of lanes of the road where the current position exists from the map data, and determines that the auxiliary route should be displayed when the number of lanes is a predetermined number (for example, three lanes) or more.
6) Whether or not you are traveling in a lane connected to an auxiliary route Use this standard because it is easier to drive without changing lanes, so if you are traveling in a lane connected to an auxiliary route, the auxiliary route is displayed This is because it is better.

  As described above, the map data stores information about lanes for each road. Lanes include straight lanes, right turn lanes, and left turn lanes. It is assumed that the map data also stores information about which lane is connected to which link. An existing method can be used as a method of determining the traveling lane. For example, the current position calculation unit 44 determines from the latitude and longitude acquired from the GPS receiver 9 whether the vehicle is located on the right, left, or center of the road. Then, it is determined whether the vehicle is in a right turn lane, a left turn lane, or a center lane (straight forward lane). The route guidance unit 43 determines whether or not the travel lane obtained by the current position calculation unit 44 is a lane connected to the auxiliary route. For example, when it is determined that the current position is on a straight lane, and the straight road is an auxiliary route, the traveling lane is a lane connected to the auxiliary route. In such a case, the route guidance unit 43 determines that the auxiliary route should be displayed.

  Although several criteria have been described above, any of these criteria may be used as a criterion for determination. In addition, when any of a plurality of (for example, two) conditions are satisfied, it may be determined that the auxiliary route should be displayed. Further, when all the criteria are satisfied, it may be determined that the auxiliary route should be displayed.

  In addition, which criterion is used may be selected by the user via the input device 5.

  In the following, when it is determined that the auxiliary route should be displayed when the difference in the predicted travel time is within the predetermined range and the difference in the distance is within the predetermined range (the above “1”) and “2)” When the standard is applied).

  When it is determined that the auxiliary route should be displayed (No in S104), the route guiding unit 43 ends the auxiliary route display process without displaying the auxiliary route.

  On the other hand, when it is determined that the auxiliary route should be displayed (Yes in S104), the route search unit 42 displays the auxiliary route (S105).

  Thereafter, the route guiding unit 43 monitors the current position and determines whether or not the vehicle has traveled on the auxiliary route. Specifically, the route guiding unit 43 determines whether or not the current position is obtained on the link constituting the auxiliary route via the current position calculating unit 44 (S106).

  If it is not determined that the vehicle has traveled along the auxiliary route (No in S106), the route guiding unit 43 deletes the display of the auxiliary route (S107) and ends the auxiliary route display process.

  On the other hand, when it determines with having drive | worked the auxiliary route (it is Yes at S106), the route guidance part 43 sets an auxiliary route to a basic route (S108). Specifically, the route from the branch intersection of the basic route to the merge intersection is replaced with an auxiliary route. Then, the auxiliary route display process ends. Thereafter, the route guiding unit 43 performs route guidance using the newly set basic route.

  FIG. 5 shows a screen display example. Usually, as shown in the screen (A), the current position 511 and the basic route 513 are displayed on the map. When an intersection to be turned right and left approaches, a map around the intersection 512 to be turned right and left and a mark 513a for prompting a right and left turn are displayed as shown in the screen (B). Further, when there is an auxiliary route (Yes in S103) and it is determined that the auxiliary route should be displayed (Yes in S104), the auxiliary route 514 is displayed as shown in the screen (B). At this time, a screen 510 displaying the intersection 512 to be turned left and right and a screen 520 for displaying the entire auxiliary route are displayed. On the screen 520, the basic route 521 and the entire auxiliary route 522 between the branching point and the junction are displayed so as to be reduced. In this way, it is possible to clearly tell the user where to join and how far to go.

  At this time, the route guidance unit 43 does not guide the user to make a right or left turn, such as “*** m ahead, turn right”. Instead, a guidance indicating that it is possible to return even if going straight, such as “If you can change lanes, turn right” is given.

  In addition, the route guiding unit 43 obtains the distance of the auxiliary route and the estimated travel time by the above-described method, and uses the basic route such as “returns to the original after ** km” and “returns to the original after * minutes”. You may make it display the message which tells the distance and time to return.

  These guidances may be displayed on the display 2 or may be performed by voice via the voice input / output device 4.

  The embodiment of the present invention has been described above.

  According to the above embodiment, according to the initial basic route, even if a right turn (or left turn) should be made at the next intersection, even if going straight ahead, if it can return to the original route without going too far, the return is made. The route for is displayed.

  Therefore, the user does not have to change the course forcibly when it is difficult to change the course for turning right or left. That is, the navigation device can provide flexible guidance.

  The present invention is not limited to the above embodiment. The above embodiment can be variously modified within the scope of the technical idea of the present invention.

  For example, in the above embodiment, an example in which the present invention is applied to a vehicle-mounted navigation device has been described, but the present invention can also be applied to a navigation device other than the vehicle-mounted navigation device.

FIG. 1 is a schematic configuration diagram of an in-vehicle navigation device to which an embodiment of the present invention is applied. FIG. 2 is a diagram illustrating a functional configuration of the arithmetic processing unit 1. FIG. 3 is a diagram illustrating a hardware configuration of the arithmetic processing unit 1. FIG. 4 is a flowchart of auxiliary route display processing. FIG. 5 is a diagram illustrating a display example of the screen.

Explanation of symbols

100: In-vehicle navigation device,
DESCRIPTION OF SYMBOLS 1 ... Arithmetic processing part, 2 ... Display, 3 ... Memory | storage device, 4 ... Voice input / output device, 5 ... Input device, 6 ... Wheel speed sensor, 7 ... Geomagnetism Sensor: 8 ... Gyro, 9 ... GPS receiver, 10 ... FM multiplex broadcast receiver, 11 ... Beacon receiver,
21 ... CPU, 22 ... RAM, 23 ... ROM, 24 ... DMA, 25 ... drawing controller, 26 ... VRAM, 27 ... color palette, 28 ... A / D converter, 29... SCI, 30... PIO, 31.
41 ... user operation analysis unit, 42 ... route search unit, 43 ... route guidance unit, 44 ... current position calculation unit, 45 ... information storage unit, 46 ... display processing unit

Claims (8)

A navigation device having a function of acquiring a current position,
A basic route searching means for searching a basic route to the destination;
Display means for displaying guidance information of the searched basic route;
Auxiliary route search means for searching for an auxiliary route that branches from the intersection on the basic route ahead of the current position and merges with the basic route at a further intersection on the basic route;
Display determination means for determining whether or not to display the auxiliary route,
The display means includes
A navigation device characterized by displaying the auxiliary route together with the basic route when the display determining means determines that the auxiliary route should be displayed. The navigation device according to claim 1,
The display determination means includes
The difference between the predicted travel time of the route from the junction point of the basic route with the auxiliary route to the junction and the predicted travel time of the auxiliary route is within a predetermined range,
And the distance difference is within a predetermined range,
A navigation device that determines that the auxiliary route should be displayed. The navigation device according to claim 1,
The display determination means includes
Means for obtaining an expected arrival time from the current position to the branch point to the auxiliary route,
The display determination means includes
When the expected arrival time is within a predetermined range,
A navigation device that determines that the auxiliary route should be displayed. The navigation device according to claim 1,
The display determination means includes
If your current position is on a road with more than a certain number of lanes,
A navigation device that determines that the auxiliary route should be displayed. The navigation device according to claim 1,
Lane specifying means for specifying a driving lane of a vehicle on which the navigation device is mounted,
The display determination means includes
When the traveling lane identified by the lane identifying means is a lane toward the auxiliary route road,
A navigation device that determines that the auxiliary route should be displayed. The navigation device according to claim 1,
The display determination means includes
When the difference between the direction of the road connected to the branch point of the basic route to the auxiliary route and the direction of the road of the auxiliary route connected to the branch point is within a predetermined range,
A navigation device that determines that the auxiliary route should be displayed. The navigation device according to claim 1,
The display determination means has the following condition a) A difference between a predicted travel time of a route from a branch point of the basic route to the auxiliary route to a junction is determined in advance. Within the specified range,
b) When the difference between the distance of the basic route from the branch point to the junction with the auxiliary route and the distance of the auxiliary route is within a predetermined range,
c) If the expected arrival time from the current position to the branch point to the auxiliary route is within a predetermined range,
d) If the current location is on a road with more than a certain number of lanes,
e) When the travel lane of the vehicle on which the navigation device is mounted is a lane toward the road of the auxiliary route,
f) When the difference between the direction of the road connected to the branch point of the basic route to the auxiliary route and the direction of the road of the auxiliary route connected to the branch point is within a predetermined range,
A navigation device that determines that the auxiliary route should be displayed when at least two of the above are satisfied. A navigation device route guidance method having a function of acquiring a current position,
A basic route search step for searching a basic route to the destination;
A display step for displaying guidance information of the searched basic route;
An auxiliary route search step for searching for an auxiliary route that branches from the intersection on the basic route ahead of the current position and merges with the basic route at an intersection further forward on the basic route;
A display determination step for determining whether or not to display the auxiliary route,
The display step includes
A route guidance method for a navigation device, comprising: displaying the auxiliary route together with the basic route when the display determining step determines that the auxiliary route should be displayed.

Images