Navigation device

Abstract

To improve a technique for recommending a traveling lane to a driver of a vehicle.SOLUTION: A navigation device is mounted on a vehicle and guides a route to be traveled by the vehicle. The navigation device includes a position information acquisition section, a storage section, a display section, and a control section. The position information acquisition section acquires current position information on the vehicle. The storage section stores road map information including information on a lane. The display section is configured to display one or more lanes of a road on which the vehicle travels, on the basis of the road map information. The control section determines a recommended lane in which traveling of the vehicle is recommended on the basis of the road map information and the route, determines a traveling lane in which the vehicle is traveling on the basis of the road map information and the current position information, and causes the display section to display the recommended lane and the traveling lane in different manners.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a navigation device. [Background technology]

[0002] A guidance system has been proposed that displays information on the possible directions of travel for each lane on a road, as well as recommended lanes for driving, by arranging icons corresponding to each lane on a display device (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2017-167089 Summary of the Invention [Problem to be solved by the invention]

[0004] In the method of showing the recommended lane by arranging icons on a display device, the connection of lanes before and after an intersection can be unclear, and it can be difficult for the driver to immediately know whether or not a lane change is necessary to stay in the recommended lane.

[0005] In view of the above, an object of the present disclosure is to improve the technology for recommending a lane in which to drive to a vehicle driver. [Means for solving the problem]

[0006] A navigation device according to one embodiment of the present disclosure is a navigation device mounted on a vehicle and providing guidance on a route on which the vehicle should travel, and is characterized in that it comprises a position information acquisition unit that acquires current position information of the vehicle, a memory unit that stores road map information including lane information, a display unit configured to display one or more lanes of the road on which the vehicle is traveling based on the road map information, and a control unit that determines a recommended lane for the vehicle to travel on based on the road map information and the route, determines the traveling lane in which the vehicle is currently traveling based on the road map information and the current position information, and displays the recommended lane and the traveling lane in different manners on the display unit. Effect of the Invention

[0007] The present disclosure provides an improvement to techniques for recommending lane directions to vehicle drivers. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a schematic configuration of a system including a navigation device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a plan view showing an example of a road on which a vehicle equipped with the navigation device of FIG. 1 is traveling. [Diagram 3] 3 is a diagram showing an example of an image displayed on a display of a navigation device when traveling on the road in FIG. 2. [Figure 4] 1. FIG. 4 is a plan view showing another example of a road on which a vehicle equipped with the navigation device of FIG. 1 travels. [Diagram 5] FIG. 5 is a diagram showing an example of a recommended lane indication shown on the display of the navigation device when traveling on the road in FIG. [Figure 6] 5 is a flowchart showing an example of a procedure for providing guidance on a recommended lane, which is executed by a control unit of the navigation device. [Figure 7] 7 is a flowchart showing an example of a procedure for a recommended lane determination process in FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that the drawings used in the following description are schematic. The dimensions and ratios on the drawings do not necessarily correspond to the actual ones. The plan view showing the road shape is for explanation purposes and differs from the actual road.

[0010] (System Overview) As shown in FIG. 1, a navigation device 10 according to an embodiment of the present disclosure is a device mounted on a vehicle 5, displays a map to a driver of the vehicle 5, and provides guidance on a driving route to a destination. The vehicle 5 includes, but is not limited to, passenger cars, trucks, buses, large and small special purpose vehicles, etc. The vehicle 5 includes various types of vehicles that will be realized in the future. For example, the vehicle 5 may include an autonomous vehicle, an amphibious vehicle, an air-land vehicle, etc.

[0011] 1, the navigation device 10 is configured to be able to acquire information from a GNSS (Global Navigation Satellite System) receiver 21, a distance sensor 22, an orientation sensor 23, and a front camera 24 in a vehicle 5. The GNSS receiver 21, the distance sensor 22, the orientation sensor 23, and the front camera 24 output information for identifying the current position of the vehicle 5.

[0012] Furthermore, the navigation device 10 may be configured to be able to communicate with various servers 30 outside the vehicle 5 via a communication network 40. The communication network 40 includes the Internet, a Virtual Private Network (VPN), a mobile communication network, and the like.

[0013] The server 30 can provide traffic information to the navigation device 10. The server 30 includes servers of government agencies in charge of traffic management, road managers, and businesses that provide traffic information. The server 30 can provide road congestion information, congestion information, accident information, and the like. The server 30 may also include a server that provides road map information. The congestion information provided by the server 30 may include information indicating the congestion situation in real time and information obtained by statistically processing past congestion information. In other words, the congestion information may include current congestion information and information on the degree of congestion on a road on a specific day of the week, at a specific time, and the like. The congestion information includes information on congestion for each lane at an intersection.

[0014] (Configuration of navigation device) The navigation device 10 includes a communication unit 11, a storage unit 12, a position information acquisition unit 13, an input unit 14, an output unit 15, and a control unit 16.

[0015] The communication unit 11 can connect to the communication network 40 by wireless communication means and acquire information from the server 30. The wireless communication means includes the fourth generation mobile communication system (4G), the fifth generation mobile communication system (5G), Wi-Fi (registered trademark), and WiMAX (Worldwide Interoperability for Microwave Access). The communication unit 11 may further support Dedicated Short Range Communication (DSRC) and the like. The communication unit 11 may also be configured to be able to receive a traffic information service using broadcast waves such as FM multiplex broadcasting.

[0016] The storage unit 12 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or any combination thereof. The semiconductor memory is, for example, a random access memory (RAM) or a read only memory (ROM). The RAM includes, for example, a static random access memory (SRAM) or a dynamic random access memory (DRAM). The ROM includes, for example, an electrically erasable programmable read only memory (EEPROM). The magnetic memory may include, for example, a hard disk. The optical memory may include, for example, a compact disc (CD), a digital versatile disc (DVD), and a Blu-ray (registered trademark) disc (BD). The storage unit 12 functions, for example, as a main storage device, an auxiliary storage device, or a cache memory. The storage unit 12 stores a program executed by the control unit 16, data used in the operation of the control unit 16, data obtained by the operation of the control unit 16, and the like.

[0017] The storage unit 12 can store road map information. The road map information includes road network information, background map information, facility information, and the like. The road network information expresses the connection and shape of roads by points called nodes and lines called links. In the road network information, intersections are represented as nodes. The position information of the nodes and links is specified by latitude and longitude. The road network information includes information on the lanes of the roads associated with the nodes and links and the possible directions of travel at intersections of each lane. The background map information includes information on the shapes of land, buildings, rivers, railway lines, and the like in the background of the road. The facility information is information on facilities included in the road map. The storage unit 12 may constantly store road map information. The storage unit 12 may temporarily store road map information read, as necessary, via the communication unit 11 from the server 30 that provides the road map.

[0018] The position information acquisition unit 13 acquires information on the current position of the vehicle 5 equipped with the navigation device 10 and / or information used for calculating the current position from the GNSS receiver 21, the distance sensor 22, the direction sensor 23, and the front camera 24. The position information acquisition unit 13 may transfer the acquired information to the control unit 16. The control unit 16 may identify the current position of the vehicle 5 based on the information acquired from the position information acquisition unit 13.

[0019] The GNSS receiver 21 is a receiver compatible with a global positioning system that uses artificial satellites. The GNSS includes systems such as the Global Positioning System (GPS), GLONASS, Galileo, and Compass. Furthermore, to improve the accuracy of position measurement, an augmentation signal from a satellite-based augmentation system (SBAS) may be used. Systems that provide augmentation signals include the Quasi-Zenith Satellite System (QZSS). Using the signal from the GNSS receiver 21, it is possible to obtain information on the latitude and longitude of the current position of the vehicle 5.

[0020] The distance sensor 22 and the direction sensor 23 are used to identify the current position in combination with a signal from the GNSS receiver 21. In a location where it is not possible to receive current position information from the GNSS receiver 21, the current position can be detected by dead reckoning using the distance sensor 22 and the direction sensor 23.

[0021] The distance sensor 22 is a sensor that measures the travel distance of the vehicle 5. The output of a vehicle speed sensor provided in the vehicle 5 can be used as the distance sensor 22. The vehicle speed sensor detects, for example, the number of rotations of the wheels to calculate the vehicle speed. The direction sensor 23 can be, for example, a gyro sensor. The gyro sensor can detect the rotational angular velocity of the vehicle 5 and obtain the direction of the vehicle 5 by integrating the angular velocity.

[0022] The front camera 24 is a camera capable of capturing an image of the road ahead of the vehicle 5. The front camera 24 may be disposed, for example, on the upper inside of the windshield of the vehicle 5. From the image of the road captured by the front camera 24, the road surface, both left and right ends of the road as seen from the vehicle 5, and / or white lines separating the lanes can be detected. Therefore, from the image of the road captured by the front camera 24, information can be obtained that identifies the position of the vehicle 5 in the width direction of the road and / or the lane in which the vehicle 5 is traveling. The image captured by the front camera 24 may be image-processed by the control unit 16 of the navigation device 10. Alternatively, the front camera 24 itself may have an image processing function and output information that identifies the position of the vehicle 5 on the road on which it is traveling and / or the lane on which it is traveling to the position information acquisition unit 13. The image captured by the front camera 24 indicates the position of the vehicle 5 on the road, and is therefore included in the current position information.

[0023] When the current position information acquired from the GNSS receiver 21 and the road map information stored in the memory unit 12 are highly accurate, the lane in which the vehicle 5 is traveling can be identified using only this information. Therefore, in this case, the front camera 24 is not necessarily required. In addition, in order to identify the lane in which the vehicle 5 is traveling, the vehicle 5 may be equipped with other detection means instead of the front camera 24. Alternatively, the vehicle 5 may acquire information identifying the lane in which the vehicle 5 is traveling from the road infrastructure or another vehicle through communication.

[0024] The GNSS receiver 21, the distance sensor 22, the orientation sensor 23, and the front camera 24 may be shared with other applications of the vehicle 5. In addition, any one or more of the GNSS receiver 21, the distance sensor 22, the orientation sensor 23, and the front camera 24 may be built into the navigation device 10.

[0025] The input unit 14 accepts input to the navigation device 10. The input unit 14 may include a touch panel formed integrally with the display 17 described below, and a microphone that accepts voice input. The touch panel is a device that detects input by the user's touch. The touch panel accepts input in conjunction with the display content of the display 17. Touch panels include various types such as capacitive, resistive, and surface acoustic wave types. The microphone converts input voice into an electrical signal and outputs it. To convert the electrical signal output by the microphone into text, the navigation device 10 may be configured to perform voice recognition processing in the control unit 16 or the like. The input unit 14 may further include a connector that receives input from an external input device.

[0026] The output unit 15 outputs information processed by the navigation device 10 to the user. The output unit 15 includes a display 17 and a speaker 18. The display 17 and the speaker 18 may be shared with devices for other purposes within the vehicle 5. The output unit 15 may include the display 17, the speaker 18, and connectors that output information to other output devices.

[0027] The display 17 is a device that displays an image based on an image signal obtained as a result of processing by the control unit 16. The display 17 may be any of various displays, such as a liquid crystal display (LCD), an organic electroluminescence (EL) display, an inorganic EL display, or a plasma display panel (PDP). The display may also be a head up display (HUD). The HUD may project a display image onto the front windshield or a combiner arranged on the dashboard. The display 17 is a display unit. The display 17 is configured to be capable of displaying one or more lanes of the road on which the vehicle is traveling, based on road map information.

[0028] The speaker 18 converts an audio signal into physical vibrations to generate sound in space. The speaker 18 may be an audio speaker installed inside the vehicle 5. The speaker 18 may be disposed in the door, dashboard, pillar, or the like of the vehicle 5. A known general speaker may be used as the speaker 18.

[0029] The control unit 16 includes at least one processor, at least one programmable circuit, at least one dedicated circuit, or any combination thereof. The processor is a general-purpose processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a dedicated processor specialized for a specific process. The programmable circuit is, for example, a field-programmable gate array (FPGA). The dedicated circuit is, for example, an application specific integrated circuit (ASIC).

[0030] The control unit 16 controls each part of the navigation device 10 and executes various calculation processes related to the operation of the navigation device 10. The control unit 16 operates each part of the navigation device 10 and makes the navigation device 10 function.

[0031] The control unit 16 guides the driving of the vehicle 5 according to the set driving route. When the vehicle 5 travels on a road with multiple lanes, the control unit 16 determines a recommended lane in which to recommend driving, based on the road map information stored in the memory unit 12 and the set driving route. The control unit 16 also determines the driving lane in which the vehicle 5 is traveling, based on the road map information and current position information of the vehicle 5. The control unit 16 can display the recommended lane and the driving lane in different forms on the display 17, and guide the driver to drive in the recommended lane.

[0032] (Lane guidance based on intersection direction) An example of a method in which the control unit 16 determines a recommended lane will be described with reference to FIG. 2. FIG. 2 shows an example of a road that is a part of a travel route of the vehicle 5. The vehicle 5 goes straight through the intersection C1, turns right at the intersection C2, and then turns left at the intersection C3 to head toward the destination. The road before the intersection C1 has four lanes, from the left, a lane L1 for going straight and turning left, a lane L2 for going straight, and lanes L3 and L4 for turning right. The road between the intersections C1 and C2 has four lanes, from the left, a lane L5 for going straight and turning left, a lane L6 for going straight, a lane L7 for turning right, and a lane L8 for turning right that branches off from the lane L7 to the right before the intersection C2. Between the intersections C2 and C3, there is a lane L9 for going straight and turning left, and a lane L10 for going straight.

[0033] At the intersection C1, the vehicle 5 goes straight. Therefore, just before the intersection C1, the vehicle 5 must travel in lane L1 or lane L2. Furthermore, at the intersection C2 next to the intersection C1, that is, the intersection two ahead from the current position of the vehicle 5, the vehicle 5 turns right. Therefore, just before the intersection C2, the vehicle 5 must travel in lane L7 or L8. Since the vehicle 5 moves to lane L7 or lane L8, it is preferable for the vehicle 5 to travel in lane L2 rather than lane L1 just before the intersection C1 in order to reduce lateral movement between the intersections C1 and C2. Therefore, the recommended lane just before the intersection C1 is lane L2. If the vehicle 5 travels in lane L2 and goes straight through the intersection C1, the vehicle 5 enters lane L6. The vehicle 5 can quickly move to lane L7 or L8 for turning right.

[0034] Furthermore, when the vehicle 5 travels between the intersections C2 and C3, the vehicle 5 must travel on the lane L9 immediately before the intersection C3 in order to turn left at the intersection C3. The vehicle 5 travels on the right-turn lanes L7 and L8 before the intersection C2, and enters the lanes L9 and L10, respectively, after turning right at the intersection C2. If the distance between the intersections C2 and C3 is short, it may be difficult to change lanes between the intersections C2 and C3. If the vehicle 5 travels on the lane L7 between the intersections C1 and C2, it will be unnecessary to change lanes after turning right at the intersection C2. Therefore, the recommended lane between the intersections C1 and C2 is the lane L7.

[0035] In this way, the control unit 16 acquires information on the travel direction for each lane at intersections on the travel route of the vehicle 5 from the road map information and determines the recommended lane. The control unit 16 may determine the recommended lane for the road currently being traveled, taking into consideration information on the travel direction for each lane at two or more upcoming intersections. The control unit 16 may determine the recommended lane so as to reduce the number of times the vehicle 5 moves between lanes. In addition, the control unit 16 may determine the recommended lane so as to avoid lane changes in a section of the road that is less than a predetermined distance away.

[0036] The control unit 16 can determine the lane in which the vehicle 5 is traveling by comparing the information indicating the range of each lane included in the road map information with the current position information of the vehicle 5 acquired from the position information acquisition unit 13. The control unit 16 may use information on the lane in which the vehicle 5 is traveling that is determined based on an image captured by the front camera 24.

[0037] FIG. 3 shows an example of an image displayed on the display 17 of the navigation device 10 in accordance with the road configuration of FIG. 2. The travel route of the vehicle 5 is shown on the road map displayed on the display 17 by coloring the roads on the travel route in a specific color, etc. An image element V represents the position of the vehicle 5. The control unit 16 displays lane information, for example, on the left or right side of the road map. Each lane is represented by a rectangle with an arrow indicating the direction of travel. The recommended lane LR is displayed in a display mode, such as color, brightness, shape, etc., different from other lanes. In addition, the control unit 16 displays the travel lane LT in which the vehicle 5 is currently traveling, using the same display of lane information. The travel lane LT is displayed in a mode different from the recommended lane LR and other lanes. The example of FIG. 3 shows that the vehicle 5 is located in the leftmost lane (lane L1) at the current position just before the intersection C1. In the display of lane information between the intersections C1 and C2, the lane that the vehicle will travel if it continues to move forward in the lane in which it is currently traveling is displayed as the travel lane LT. When the recommended lane LR and the driving lane LT match, the control unit 16 does not need to cause the display 17 to display the driving lane LT.

[0038] As described above, by displaying the recommended lane LR and the driving lane LT in different ways on the display of road lane information, the driver can easily understand whether the vehicle 5 is traveling in the recommended lane LR or not.

[0039] Furthermore, when the driving lane LT is different from the recommended lane LR, the control unit 16 may issue an audio notification using the speaker 18. The audio notification may include a message instructing the driver to move to the recommended lane. In this way, the driver can recognize that he or she should change lanes even if he or she is not looking at the display 17.

[0040] 3, the display 17 of the navigation device 10 displays not only lane information of the road up to the intersection C1 on which the vehicle is currently traveling, but also lane information up to the intersection C2 beyond that. However, it is not essential to display information on the recommended lane after passing through the intersection C1 in this manner. The navigation device 10 may display to the driver only the recommended lane and the driving lane on the road on which the vehicle is currently traveling at each point in time.

[0041] (Lane guidance during congestion and traffic jams) The navigation device 10 can guide the user to change lanes depending on the congestion or traffic jam conditions of the road. The navigation device 10 can obtain statistical congestion information from the server 30 and store it in the storage unit 12. The statistical congestion information includes, for example, information on lanes that are likely to become congested during a specific time period on a specific day of the week. The statistical congestion information may also include information on lanes that are likely to become congested due to the structure of the road, such as lanes where right-turning vehicles are likely to wait to turn right because there is no dedicated right-turn lane.

[0042] Furthermore, the navigation device 10 may obtain real-time congestion information from the server 30. The congestion information may include information on the degree of congestion for each lane. The degree of congestion may be evaluated, for example, based on the length of a line of vehicles caused by congestion and the time it takes to pass through an intersection where congestion is occurring. When the degree of congestion is higher than a predetermined standard, the server 30 or the control unit 16 may determine that a traffic jam is occurring.

[0043] FIG. 4 shows an example of a road on which a vehicle 5 travels together with other vehicles. In the road of FIG. 4, the set travel route of the vehicle 5 is assumed to be to go straight through an intersection C4 and then go straight through an intersection C5. Before the intersection C4, there is a lane L11 for going straight and turning left, and a lane L12 for going straight and turning right. Between the intersections C4 and C5, there are a lane L13 for going straight and turning left, a lane L14 for going straight, and a lane L15 for turning right that branches off from the lane L14. At the intersection C4, lane L12 does not have a dedicated lane for right turns, so it is assumed that right-turning vehicles are likely to have to wait a long time to turn right. In addition, at the intersection C5, there is a traffic jam of left-turning vehicles on lane L13.

[0044] In this case, in order to avoid congestion or traffic jams, it is preferable for the vehicle 5 to travel on the lane L11 before the intersection C4, and on the lane L14 between the intersections C4 and C5.

[0045] In such a case, the control unit 16 may determine a recommended lane LR as shown in FIG. 5 so as to avoid congestion based on the congestion information. The control unit 16 may also determine a lane where congestion is occurring as a non-recommended lane LU. A non-recommended lane is a lane on which the navigation device 10 does not recommend the driver to travel. The control unit 16 may display the non-recommended lane LU in the lane information on the display 17 in a manner different from the recommended lane LR, the travel lane LT, and other lanes. The control unit 16 may generate a warning message from the speaker 18 when the vehicle 5 is traveling on the non-recommended lane LU.

[0046] As described above, the driver can avoid congestion by following the recommended lane LR displayed on the display 17. In particular, the navigation device 10 displays highly congested lanes as non-recommended lanes LU and issues a warning not to drive on them, so the driver can avoid getting into a queue of traffic jams.

[0047] The method of determining a recommended lane based on the traveling direction at an intersection described above with reference to Figures 2 and 3 and the method of determining a recommended lane based on congestion information described above with reference to Figures 4 and 5 can be used in combination. For example, when there are multiple lanes available for travel, the control unit 16 may determine the lane so that the vehicle travels in the lane with the lower degree of congestion, taking into consideration the congestion information as a priority. The control unit 16 can also quantify the disadvantage of changing lanes and the additional disadvantage of passing through the congestion, and determine the lane with the lower total disadvantage as the recommended lane.

[0048] (Procedure for providing recommended lanes) An example of a process of providing recommended lanes by the control unit 16 of the navigation device 10 will be described below with reference to the flowcharts of Figures 6 and 7. The method disclosed in this specification can be executed by a processor included in the control unit 16 according to a program. Such a program can be stored in a non-transitory computer-readable medium. Examples of non-transitory computer-readable media include, but are not limited to, a hard disk, a RAM, a ROM, a flash memory, a CD-ROM, an optical storage device, a magnetic storage device, and the like.

[0049] First, as shown in FIG. 6, the control unit 16 acquires the destination input by the user from the input unit 14, and searches for a driving route from the current location information detected by the location information acquisition unit 13 to the destination on the road map information stored in the memory unit 12, thereby setting the driving route (S101).

[0050] Next, when the road on which the vehicle is traveling has multiple lanes, the control unit 16 performs a process of determining a recommended lane (S102). An example of the process of determining the recommended lane is shown in Fig. 7. The process of determining the recommended lane will be described below with reference to Fig. 7.

[0051] The control unit 16 searches the road map information stored in the memory unit 12 and acquires information on lanes at the next intersection on the road currently being traveled (S201). The control unit 16 acquires information on the configuration of lanes just before the intersection and the travel direction of each lane.

[0052] The control unit 16 extracts lanes that can be traveled in the travel direction indicated by the travel route at the next intersection from the travel direction of each lane and information on the set travel route (S202). The lanes extracted in S202 become candidates for recommended lanes.

[0053] The control unit 16 determines whether the number of lanes extracted in S202 is one or multiple (S203). If only one lane is extracted in S202 (S203: Yes), this means that the vehicle has no choice but to pass through that lane in order to proceed along the travel route. Therefore, the control unit 16 determines that lane as the recommended lane (S209).

[0054] When there are multiple lanes extracted in S202 (S203: No), the control unit 16 searches for statistical congestion information stored in the memory unit 12 or congestion information obtained in real time from the server 30 via the communication network 40, and confirms the congestion information related to the extracted lanes (S204).

[0055] When there is congestion information for the extracted lane (S204: Yes), the control unit 16 excludes lanes with a relatively high degree of congestion from the candidates for recommended lanes (S205). The control unit 16 may determine that there is congestion information only when congestion with a degree of congestion higher than a predetermined value occurs. When there is no difference in the degree of congestion among the extracted multiple lanes, the control unit 16 does not need to exclude any lane.

[0056] After S205, the control unit 16 determines whether the number of lanes that are candidates for the recommended lane is one or multiple (S206). If there is one candidate for the recommended lane (S206: Yes), the control unit 16 determines that lane as the recommended lane (S209).

[0057] In S204, if there is no congestion information for the extracted lane (S204: No), and in S206, if there are multiple candidates for recommended lanes (S206: No), the control unit 16 acquires information on the intersection two junctions ahead (S207) from the road map information stored in the storage unit 12. The control unit 16 acquires information on the lane configuration and the travel direction of each lane at the intersection two junctions ahead.

[0058] The control unit 16 extracts lanes that can be traveled in the traveling direction of the intersection two intersections away on the road between the intersection one intersection away and the intersection two intersections away. The control unit 16 selects a lane that is easy to move to the extracted lane from the lanes of the road on which the vehicle is currently traveling (S208). For example, the control unit 16 selects a lane that the vehicle will enter into the extracted lane based on the traveling direction at the intersection two intersections away after the vehicle passes the intersection one intersection away.

[0059] In addition, when one lane cannot be determined as the recommended lane from multiple candidate recommended lanes even after taking into account the direction of travel at the intersection two intersections away, the control unit 16 may further select the recommended lane by taking into account the direction of travel at the intersection three intersections away.

[0060] After S208, the control unit 16 determines the recommended lane (S209). When there are multiple candidates for the recommended lane, the control unit 16 may set the multiple lanes as the recommended lanes. After S209, the control unit 16 returns to the flowchart of FIG.

[0061] After determining the recommended lane in S202, the control unit 16 determines the driving lane, which is the lane on which the vehicle is currently traveling (S103). The control unit 16 may identify the driving lane from the current position information acquired from the GNSS receiver 21 and lane information of the road on which the vehicle is currently traveling, which is included in the road map information. The control unit 16 may also identify the driving lane from an image acquired from the front camera 24 and lane information of the road on which the vehicle is currently traveling, which is included in the road map information. The position information acquired from the GNSS receiver 21 and information acquired from the image from the front camera 24 may also be used in combination.

[0062] The control unit 16 causes the display 17 to display an image showing the lane in which the vehicle is currently traveling, as shown as the lane information in Fig. 3. The control unit 16 then displays the recommended lane and the traveling lane on the image of the lane information (S104). This allows the user to easily understand whether or not the vehicle is currently traveling in the recommended lane.

[0063] The control unit 16 determines whether the driving lane matches the recommended lane (S105). If the driving lane does not match the recommended lane (S105: No), the control unit 16 notifies the driver that he should drive in the recommended lane (S106). For example, the control unit 16 can use the speaker 18 to give the driver a voice guide such as "Please move to the right lane."

[0064] When the driving lane matches the recommended lane (S105: Yes), the control unit 16 does not need to issue a notification using voice or the like while displaying the recommended lane on the display 17. This is because there is no problem with the vehicle 5 continuing to drive in the lane.

[0065] The control unit 16 monitors the vehicle 5 passing through the intersection based on the current position information and road map information (S107). The control unit 16 waits until the vehicle 5 passes through the intersection (S107: No).

[0066] When the control unit 16 determines that the vehicle 5 has passed the intersection (S107: Yes), it determines whether there is a next intersection on the travel route (S108). If there is no next intersection (S108: No), it means that the vehicle has arrived in the vicinity of the destination. The control unit 16 ends the process of guiding the driver to the recommended lane. If there is a next intersection because the vehicle has not arrived in the vicinity of the destination (S107: Yes), the control unit 16 returns to step S102 and continues the process of guiding the driver to the recommended lane.

[0067] As described above, according to this embodiment, the recommended lane and the driving lane are displayed in different modes, so that the driver of the vehicle 5 can immediately know whether or not a lane change is necessary to travel in the recommended lane. Therefore, the technology for recommending a driving lane to the driver of the vehicle 5 is improved.

[0068] The present invention is not limited to the above-described embodiment, and many variations or modifications are possible. For example, the functions included in each means, step, etc. can be rearranged so as not to cause logical inconsistencies, and multiple means or steps can be combined into one or divided.

[0069] Although the drawings of the above embodiment are based on the premise of a left-hand traffic system in which vehicles drive on the left side of the road, the present invention can also be effectively applied to a right-hand traffic system.

[0070] In the above embodiment, the recommended lane is determined based on the traveling direction of each lane at the intersection. However, in the present invention, the recommended lane may be determined in consideration of the lane to be traveled when there are points on the road where there are fewer lanes, more lanes, branches, merging points, etc., as well as the degree of congestion.

[0071] Furthermore, in the above embodiment, a process of determining a recommended lane and guiding the driver to the recommended lane is performed every time an intersection is passed. However, the recommended lane may be guided to the driver when the distance to the next intersection is shorter than a predetermined distance. For example, when adjacent intersections are far apart, the control unit 16 may perform a process of guiding the driver to the recommended lane when the distance to the next intersection is, for example, within 200 m, 300 m, or 500 m. Furthermore, the predetermined distance may change according to the traveling speed of the vehicle 5.

[0072] In the above embodiment, the processing of the navigation device 10 is executed by the control unit 16 in the navigation device 10. However, at least a part of the processing of the control unit 16 may be executed by a computer external to the navigation device 10 via the communication network 40. [Explanation of symbols]

[0073] 1 System 5. Vehicles 10 Navigation devices 11 Communications Department 12 Storage section 13 Location information acquisition section 14 Input section 15 Output section 16 Control section 17 Display (Display unit) 18 Speaker 21 GNSS receiver 22 Distance Sensor 23 Orientation Sensor 24 Front Camera 30 Servers 40 Network C1~C5 Intersection L1~L15 lanes LT Travel Lane LR Recommended lane LU Non-recommended lanes V Image Element

Claims

1. A navigation device mounted on a vehicle for guiding a route along which the vehicle should travel, comprising: a location information acquisition unit that acquires current location information of a vehicle; A storage unit for storing road map information including lane information; a display unit configured to display one or more lanes of a road on which the vehicle is traveling based on the road map information; a control unit that determines a recommended lane in which the vehicle is to be driven based on the road map information and the route, determines a driving lane in which the vehicle is currently driving based on the road map information and the current position information, and displays the recommended lane and the driving lane in different modes on the display unit; A navigation device comprising:

2. The navigation device according to claim 1 , wherein the control unit is configured to notify a driver of the vehicle when the recommended lane and the driving lane differ from each other.

3. The navigation device according to claim 2 , wherein the control unit determines the recommended lane by taking into consideration a traveling direction at two or more upcoming intersections on the route.

4. 2. The navigation device according to claim 1, wherein the control unit is configured to acquire congestion information indicating congestion of each of the lanes, the congestion information including at least one of statistical congestion information and real-time congestion information, and determines a lane with relatively less congestion as the recommended lane with priority.

5. 2. The navigation device according to claim 1, wherein the control unit is configured to acquire congestion information indicating the occurrence of congestion in each of the lanes, determine a lane whose congestion level is greater than a predetermined standard as a non-recommended lane, and cause the display unit to display the non-recommended lane in a manner different from the recommended lanes.

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