Guidance correction method and guidance correction device

Abstract

This guidance correction method is executed by a controller 12 to correct guidance to a destination, in which the controller 12: acquires a map target object from a database 15; detects an object at a position away from a guidance point by a first distance using a sensor while traveling along a travel route; determines whether or not the map target object matches the object; and if it is determined that the map target object does not match the object, corrects guidance information at the guidance point, and outputs the corrected guidance information.　

Description

[Technical Field]

[0001] The present invention relates to a guide correction method and a guide correction device. [Background technology]

[0002] Conventionally, map information management devices that manage map information have been known (see, for example, Patent Document 1). The map information management device described in Patent Document 1 acquires a position where a vehicle has performed an operation different from that of the guide route, acquires an image of the acquired position from an imaging unit, generates difference information between the landmark information acquired from the image and the landmark information included in the map information of the position where it has been determined that the vehicle has performed an operation different from that of the guide route, and updates the landmark information based on the difference information. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 087302 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the map information management device described in Patent Document 1, when a vehicle first arrives at a different landmark location than the actual one, guidance is provided based on the landmark information before the update, and guidance regarding the difference in the landmark is not provided, resulting in a problem of low reliability of the guidance.

[0005] The problem to be solved by the present invention is to provide a guidance correction method and a guidance correction device that improve the reliability of guidance. [Means for solving the problem]

[0006] The present invention solves the above problem by acquiring map landmarks from a database, detecting an object at a position a first distance away from a guidance point using a sensor while traveling along a route, determining whether the map landmark matches the object, and if it is determined that the map landmark does not match the object, correcting guidance information at the guidance point and outputting the corrected guidance information. [Effects of the Invention]

[0007] According to the present invention, the reliability of guidance can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram of a route guidance system including a guidance correction device according to an embodiment of the present invention. [Figure 2] FIG. 4 is a flowchart illustrating an example of a control procedure for executing a guidance correction method according to an embodiment of the present invention. [Figure 3] FIG. 4 is a flowchart illustrating an example of a control procedure for executing a guidance correction method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. In this embodiment, a guidance correction method and a guidance correction device according to the present invention are described as being applied to a route guidance system.

[0010] FIG. 1 is a block diagram of a route guidance system including a guidance correction device 10 according to this embodiment. As shown in FIG. 1, the route guidance system is installed in a vehicle 1 and includes a position acquisition device 2, an external sensor 3, an internal sensor 4, a database 5, and a guidance correction device 10. The position acquisition device 2, the external sensor 3, the internal sensor 4, the database 5, and the guidance correction device 10 are mounted on the vehicle 1 and exchange information with one another via an in-vehicle network such as a CAN. In the route guidance system, the guidance correction device 10 provides route guidance from the user's current location to a destination to a user riding in the vehicle 1. The guidance correction device 10 is, for example, a navigation device mounted on the vehicle 1. In this embodiment, the guidance correction device 10 is described as an in-vehicle navigation device, but is not limited thereto and may also be a terminal device carried by the user.

[0011] The guidance correction device 10 outputs guidance information to the user during route guidance. The guidance information includes, for example, a map and a route from the user's current location to the destination. Furthermore, when the user approaches a guidance point where route guidance is required, the guidance correction device 10 outputs guidance information including the direction of travel at the guidance point to the user. A guidance point is, for example, a point where two or more routes can be entered, such as an intersection, a branch point, or an interchange on a highway. Even if the point does not have two or more routes, it can be set as a guidance point if it is needed to accurately guide the vehicle's direction of travel. In other words, the guidance correction device 10 can determine and use, in advance, a point that accurately guides the vehicle's direction of travel as a guidance point. The user drives the vehicle 1 according to the route guidance.

[0012] The position acquisition device 2 acquires the position information of the vehicle 1 as the user's position information. The position acquisition device 2 acquires the position information of the vehicle 1 from, for example, a GPS satellite. The position of the vehicle 1 is expressed by longitude and latitude. The position acquisition device 2 acquires the position information from the GPS satellite at predetermined intervals.

[0013] The external sensor (on-board sensor) 3 detects the surrounding environment including objects around the user. The external sensor 3 may be, for example, a camera installed on the vehicle 1, and may be a camera equipped with an imaging element such as a CCD or CMOS. The external sensor 3 is not limited to an on-board camera, and may be a distance measuring device such as a laser. The external sensor 3 acquires surrounding images capturing images of objects around the vehicle. The objects are landmarks in the surrounding environment around the vehicle. The objects include static objects and dynamic objects. Examples of static objects include advertising billboards, signs, stop lines, traffic lights, crosswalks, traffic restrictions, road trees, buildings, and road structures. Examples of road structures include bridges and tunnels. Examples of dynamic objects include automobiles (other vehicles) other than the user's vehicle, motorcycles, bicycles, pedestrians, etc. Objects stored in the map data include landmarks such as convenience stores, restaurants, and gas stations. Objects not stored in the map data are dynamic objects such as automobiles (other vehicles) other than the user's vehicle.

[0014] The exterior sensor 3 detects the direction of an object around the user and the distance to the object. For example, the exterior sensor 3 is a millimeter-wave radar, a laser radar, an ultrasonic radar, a laser range finder, etc. Surrounding environment information including the surrounding environment detected by the exterior sensor 3 is output to the guidance correction device 10 at predetermined intervals.

[0015] The interior sensor 4 detects the state of the user inside the vehicle. The interior sensor 4 may be, for example, a camera installed inside the vehicle 1, and may be a camera equipped with an imaging element such as a CCD or CMOS. The interior sensor 4 may, for example, continuously capture user images including the user's face. The interior sensor 4 may detect the user's biometric information. The user's biometric information includes the user's heart rate, sweat, body temperature, and pulse rate.

[0016] The database 5 is a database that stores various information. The database 5 is a recording medium that stores information about landmarks, and stores map information. The map information includes at least road information and information about map landmarks (landmark information). In the following description, landmarks stored in the database correspond to map landmarks. The road information includes road types (e.g., general roads, toll roads, etc.) and the locations of intersections, stop lines, traffic lights, and road signs. Landmarks are features that can serve as targets for route guidance, and landmark information includes information about map landmarks such as convenience stores, restaurants, and gas stations. In other words, landmark information is information about map landmarks at guidance points that require guidance. For example, when providing route guidance such as "Turn left at the intersection with a gas station," the gas station becomes a map landmark. Note that road information may also serve as landmark information. For example, information about an intersection can serve as a map landmark for route guidance, such as "Turn right at the next intersection." The map information also includes location information of guidance points that require guidance.

[0017] The guidance correction device 10 provides route guidance to the user (passenger) to the destination and also corrects guidance information at guidance points. The guidance correction device 10 includes an output device 11 and a controller 12. In the guidance correction device 10, the controller 12 acquires information from the position acquisition device 2, the vehicle exterior sensor 3, the vehicle interior sensor 4, and the database 5, generates guidance information necessary for route guidance based on the acquired information, and outputs the guidance information to the user via the output device 11, thereby providing the user with route guidance to the destination and correcting the guidance information at guidance points.

[0018] The output device 11 is an output interface that outputs route guidance based on the generated route. The output device 11 displays the route generated by the guidance correction device 10, the current location, the contents of the corrected guidance, etc. on a screen to the user, and also outputs the guidance information generated by the guidance correction device 10 as audio. The output device 11 is composed of one or more devices. For example, the output device 11 is composed of a display that displays the route guidance and guidance information on a screen, and a speaker that outputs audio data of the route guidance and guidance information. Examples of displays include a liquid crystal panel and an organic EL panel.

[0019] The controller 12 comprises a computer having hardware and software, including a ROM storing programs, a CPU that executes the programs stored in the ROM, and a RAM that functions as an accessible storage device.

[0020] 1, the controller 12 is configured to include, as functional blocks, an information acquisition unit 13, a target detection unit 14, a determination unit 15, and a route guidance unit 16, and executes each function through cooperation between software for executing each process and hardware. Note that in this embodiment, the functions of the controller 12 are divided into four blocks, and the functions of each functional block will be explained, but the functions of the controller 12 do not necessarily have to be divided into four blocks.

[0021] The information acquisition unit 13 acquires information on the current position of the vehicle from the position acquisition device 2. The information acquisition unit 13 acquires map information including road information and landmark information from the database 5. The map information is used to calculate the driving route to the destination and to identify landmarks at guidance points. Note that if the route calculation to the destination is performed externally, the information acquisition unit 13 may acquire information on the driving route including destination information.

[0022] The information acquisition unit 13 acquires various types of information. The information acquisition unit 13 acquires, from the vehicle exterior sensor 3, surrounding environment information detected by the vehicle exterior sensor 3. The surrounding environment information is information indicating the environment around the vehicle, and corresponds to an image captured by a camera included in the vehicle exterior sensor 3.

[0023] The information acquisition unit 13 may acquire a captured image of the user from a camera of the in-vehicle sensor 4, or biometric information of the user from a biometric sensor. The information acquired by the information acquisition unit 13 is transmitted to the landmark detection unit 14, the determination unit 15, and the route guidance unit 16.

[0024] While the vehicle 1 is traveling along the travel route, the target detection unit 14 uses the external sensor 3 to detect an object from a position a first distance away from the guidance point. The object is a feature that can serve as a target for route guidance and represents a feature that exists in the actual travel environment. In this embodiment, the target detected by the external sensor 3 is referred to as an "object." The object corresponds to a map feature and is a feature such as a convenience store, restaurant, or gas station. The object may also be a feature indicated by road information. The first distance is a distance determined in advance based on the distance at which the external sensor 3 can detect the object. For example, if the on-board sensor 3 is an on-board camera, the first distance corresponds to a distance equivalent to the imaging range of the on-board camera or a distance shorter than the imaging range of the on-board camera. In other words, when the vehicle 1 is located a first distance away from the guidance point, the on-board camera can capture an image of the object at the guidance point. The route guidance unit 16, which will be described later, calculates a travel route to the destination and sets a guidance point requiring guidance on the calculated travel route. In the following description, an embodiment will be described in which an on-board camera is mainly used as an example of the outside-vehicle sensor 3, but a distance measuring device may be used instead of the on-board camera. In the case of a distance measuring device, the imaging range in the following description may be used as the detection range, and the captured image may be replaced with the detection value of the distance measuring device.

[0025] The landmark detection unit 14 acquires route guidance information including guide points from the route guidance unit 16, and identifies the positions of the guide points indicated in the route guidance information and the positions of map landmarks at the guide points by referring to map information. The route guidance information includes information on a driving route to a destination, information on guide points that require guidance when driving along the driving route, and information on map landmarks at the guide points. The landmark detection unit 14 measures the distance from the current position of the vehicle to the next guide point. When the measured distance reaches a first distance, it acquires an image captured by the in-vehicle camera. The acquired image may be an image captured at the time when the measured distance reaches the first distance or immediately before the measured distance reaches the first distance. The landmark detection unit 14 then detects, from the captured image, a landmark that is captured at the guide point identified from the route guidance information.

[0026] The determination unit 15 determines whether a map landmark matches an object. The determination unit 15 determines whether a map landmark at a guidance point identified from route guidance information matches an object detected by the landmark detection unit 14 using the external sensor 3. Whether a map landmark actually exists at the guide pointThe determination is made based on the result of detecting a landmark using the captured image. For example, assume that the route guidance indicated in the route guidance information is "Turn left at the intersection where there is a convenience store." The landmark detection unit 14 detects an object located at the intersection, which is the guidance point, from the captured image. The determination unit 15 determines whether the map landmark indicated in the route guidance information matches the object detected by the landmark detection unit 14. The determination of the match between the map landmark and the object also takes into account the position. When the route guidance is "Turn left at the intersection where there is a convenience store," if it is possible to detect from the captured image that a convenience store is located at the intersection, the determination unit 15 determines that the object is present at the guidance point. On the other hand, if it is possible to detect that a convenience store is not located at the intersection, or if it is not possible to detect that a convenience store is located at the intersection, the determination unit 15 determines that the object is not present at the guidance point. Then, since the object does not exist at the guidance point, the determination unit 15 determines that the map landmark does not match the object. Furthermore, if it is detected that a landmark other than the convenience store is located at the intersection, the determination unit 15 determines that the map landmark does not match the object based on the difference between the position of the map landmark and the position of the object. Note that, regarding the determination of whether the positions match, the determination unit 15 may determine that the positions match if the difference in position is within a predetermined range set according to the detection error.

[0027] The route guidance unit 16 provides route guidance so that the vehicle 1 travels along a travel route from the current position of the vehicle 1 to the destination. When the route guidance unit 16 acquires the current position of the vehicle 1 and the destination of the vehicle 1, the route guidance unit 16 references map information stored in the database 5 and generates a travel route from the current position of the vehicle 1 to the destination. The route guidance unit 16 uses the position information acquired by the position acquisition device 2 as the current position of the vehicle 1. The route guidance unit 16 also uses destination information input by the user as the destination of the vehicle 1. The travel route may be a route that passes through multiple destinations. The route guidance unit 16 displays a map, a travel route, the current position of the vehicle 1, etc. on a screen to the user via the output device 11.

[0028] Furthermore, the route guidance unit 16 extracts guide points located on the travel route based on route information and map information of the travel route. Furthermore, when the vehicle 1 starts traveling along the travel route, the route guidance unit 16 periodically acquires the current position of the vehicle 1 and determines whether the vehicle 1 is approaching the guide point based on the current position of the vehicle 1 and the position of the guide point on the travel route. When the vehicle 1 approaches the guide point, the route guidance unit 16 causes the output device 11 to output guide information for the guide point. For example, the route guidance unit 16 may cause the output device 11 to output the generated guide information as voice, or may display on the screen text or an icon such as an arrow indicating the direction in which the user should travel.

[0029] The route guidance unit 16 provides route guidance for a guide point in two stages: advance guidance and last-minute guidance. Advance guidance is provided when the driver cannot see the guide point and is provided at a location a second distance away from the guide point. The second distance is set to be longer than the first distance and at least longer than the distance corresponding to the imaging range of the external sensor 3. In other words, advance guidance is provided at a location far enough away that the external sensor 3 cannot capture an image of the guide point. The route guidance unit 16 provides advance guidance to the user, including information on the remaining distance to the guide point, landmark information at the guide point, and driving operation information at the guide point. The landmark information used in advance guidance is map landmark information stored in the database 5. This enables route guidance that prompts the driver to prepare in advance. In advance guidance, for example, a message such as "Approximately 300 meters ahead, turn left at the intersection where there is a convenience store" is output. This advance guidance allows the driver to confirm landmarks and prepare for driving operations before actually seeing the convenience store.

[0030] The last-minute guidance is a guidance that is given after the advance guidance and is given at the same guidance location as the advance guidance. The driverThe last-minute guidance is provided between a position less than a first distance from the guidance point and the guidance point. The last-minute guidance is provided when the driver is close enough to the guidance point that the driver can see it, and is provided at least within a range where the external sensor 3 can capture an image of the guidance point. The route guidance unit 16 provides the user with last-minute guidance by including landmark information at the guidance point and driving operation information at the guidance point in the guidance information. The landmark information used in the last-minute guidance is the destination information detected by the external sensor 3. In last-minute guidance, for example, a message such as "Turn left soon at the intersection where there is a convenience store" is output. When the driver hears the last-minute guidance message, they can confirm the presence of the landmark (convenience store) assumed in the advance guidance at the visible intersection and confirm that the guidance point is just around the corner.

[0031] As described above, the landmarks for advance guidance are identified from landmark information stored in a database, and the landmarks (objects) for last-minute guidance are detected from images captured by an onboard camera. Therefore, map information may not be updated in time, and the map landmarks recorded in the database may differ from the actual objects detected from the images captured by the onboard camera. Furthermore, for example, an obstacle near the landmark (e.g., a tree or a building separate from the landmark) may prevent the onboard camera from capturing an image of the object, and the driver may not be able to see the map landmark used in advance guidance.

[0032] Therefore, in this embodiment, the determination unit 15 compares the map landmark used in advance guidance with the object detected near the guidance point during last-minute guidance, and determines, based on the comparison result, whether the map landmark used in advance guidance matches the object. That is, the determination unit 15 performs a determination as to whether the map landmark matches the object for landmarks for which route guidance has been performed in advance guidance. If it is determined that the landmark used in advance guidance does not match the object, the route guidance unit 16 modifies the guidance information for route guidance at the guidance point and performs last-minute guidance using the modified guidance information. On the other hand, if it is determined that the landmark used in advance guidance matches the object, the route guidance unit 16 performs last-minute guidance without modifying the route guidance at the guidance point.

[0033] The correction of the guidance information by the route guidance unit 16 is a correction of information related to landmarks, in other words, a correction of the content for guiding to the destination. The guidance information corrected by the route guidance unit 16 may include corrected guidance information that corrects the existence of landmarks and / or alternative guidance information that replaces the landmarks. For example, consider a case where the route guidance unit 16 outputs a message in advance guidance such as "Approximately 300 meters ahead, turn left at the intersection where there is a convenience store," but there is actually no "convenience store." In such a case, the route guidance unit 16 outputs a message such as "There is no convenience store," as correction guidance, informing the user that the map landmark used in advance guidance does not exist at the guidance point. In other words, the correction guidance information is information for correcting the existence of landmarks indicated in advance guidance.

[0034] The alternative guidance is different from the advance guidance and assists the driver in identifying the guidance point. The alternative guidance information may include at least one of information on an alternative landmark different from the map landmark before the correction, the road shape and / or road structure at the guidance point, and a dynamic object. The map landmark before the correction is the landmark used in the advance guidance. For example, assume that the last-minute guidance before the correction outputs a message such as "Turn left at the intersection where there is a gas station," but there is actually no "gas station." In such a case, if there is a "convenience store" at the guidance point, the route guidance unit 16 outputs a message such as "Turn left at the intersection where there is a convenience store" as the alternative guidance information. As a result, another alternative landmark is used for the alternative guidance information.

[0035] As another example of alternative guidance, if the road at the guidance point is an intersection, the route guidance unit 16 includes information about the intersection in the route guidance information and outputs a message such as "Turn left at the next traffic light intersection" as the alternative guidance information. In this way, the road shape and road structure existing at the guidance point are used for alternative guidance. As another example of alternative guidance, if a moving object is detected by the external vehicle sensor 3 at or around the guidance point, the route guidance unit 16 outputs a message such as "Follow the car in front" as the alternative guidance information. In this way, the moving object is used for alternative guidance. Note that the route guidance unit 16 does not include information about the intersection in the route guidance information. Inside information When correcting information, the guidance for the target object is corrected without correcting the driving route. Running The route may be modified.

[0036] Then, the route guidance unit 16 corrects the guidance information to the destination in the above manner and outputs the corrected guidance information from a position that is less than the first distance away from the guidance point. This prevents a discrepancy between the driver's recognition prepared based on the advance guidance and the situation of the guidance point that the driver actually sees, when the map landmark used in the advance guidance does not match the object.

[0037] When outputting a message indicating correction guidance, the route guidance unit 16 may generate a message of the corrected guidance information according to the voice interface. For example, the correction message may be expressed in a way that directly corrects the message output in the advance guidance, an apology, a friendly expression, or the like. This allows the impression of the output content to be adapted according to the characteristics of the voice interface.

[0038] Next, the control procedure of the guidance correction method executed by the guidance correction device 10 will be described with reference to Fig. 2. Fig. 2 is a flowchart showing an example of the control procedure for executing the guidance correction method according to this embodiment. The control flow in Fig. 2 is a control flow when providing advance guidance. The control flow in Fig. 2 is repeatedly executed while the vehicle 1 is traveling until it arrives at the destination.

[0039] When the vehicle 1 starts traveling along the travel route, the controller 12 starts the control flow from step S1. In step S1, the information acquisition unit 13 acquires information on the current position of the vehicle 1 from the position acquisition device 2. The information acquisition unit 13 also acquires information from the outside vehicle sensor 3 and the inside vehicle sensor 4. In step S2, the route guidance unit 16 determines whether the current position of the vehicle 1 has reached the advance guidance position. The advance guidance position is a position that is a second distance away from the guidance point. If the current position of the vehicle 1 has not reached the advance guidance position, the controller 12 returns to the control flow of step S1 and executes the control flow from step S1 onwards.

[0040] In step S3, the route guidance unit 16 acquires landmark information from the database and identifies map landmarks at guidance points on the travel route. In step S4, the route guidance unit 16 provides advance guidance using the map landmarks identified from the landmark information in the database 5. Then, the controller 12 ends the control flow shown in FIG.

[0041] Next, the control procedure of the guidance correction method executed by the guidance correction device 10 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing an example of the control procedure for executing the guidance correction method according to this embodiment. The control flow in Fig. 3 is a control flow when last-minute guidance is performed. The control flow in Fig. 3 is executed after advance guidance.

[0042] In step S11, the information acquisition unit 13 acquires information on the current position of the vehicle 1 from the position acquisition device 2. The information acquisition unit 13 acquires information from the external vehicle sensors 3 and the internal vehicle sensors 4. In step S12, the route guidance unit 16 determines whether the current position of the vehicle 1 has reached the previous guidance position. The previous guidance position is a position that is a first distance away from the guidance point. If the current position of the vehicle 1 has not reached the previous guidance position, the controller 12 returns to the control flow of step S11 and executes the control flow from step S11 onwards. In step S13, the route guidance unit 16 identifies a map landmark. The map landmark is a map landmark used in advance guidance, and corresponds to a landmark identified from the landmark information in the database 5.

[0043] In step S14, the landmark detection unit 14 detects an object from a position a first distance away from the guidance point using the external vehicle sensor 3 while the vehicle 1 is traveling along the guided travel route. In step S15, the determination unit 15 determines whether the map landmark matches the object. If it is determined that the map landmark does not match the object, the route guidance unit 16 modifies the guidance information. Then, in step S17, the route guidance unit 16 provides last-minute guidance by outputting the modified guidance information from a position where the vehicle 1 is less than the first distance away from the guidance point. On the other hand, if it is determined that the landmark is present at the guidance point, the route guidance unit 16 does not modify the guidance information, and in step S17, the route guidance unit 16 provides last-minute guidance. Then, the controller 12 ends the control flow shown in FIG. 3.

[0044] As described above, the guidance correction method and guidance correction device 10 according to this embodiment acquires a map landmark, which is a landmark at a guidance point requiring guidance, from a database 5 that stores information about landmarks. While traveling along a route guided by route guidance, the vehicle uses an external sensor (on-board sensor) 3 to detect an object from a position a first distance away from the guidance point, determines whether the map landmark matches the object, and if it determines that the map landmark does not match the object, corrects the guidance information for the guidance point and outputs the corrected guidance information from a position less than the first distance away from the guidance point. This allows appropriate guidance to be provided when a landmark identified from the information recorded in the database does not actually exist at the guidance point. As a result, the reliability of the guidance can be improved.

[0045] In this embodiment, the controller 12 provides route guidance including the destination from a position that is the second distance away from the guidance point, and the determination by the determination unit 15 as to whether the map landmark matches the object is performed for the map landmark for which route guidance has already been provided. This allows appropriate guidance to be provided when the map landmark used in advance guidance does not match the object.

[0046] In this embodiment, the revised guidance information includes corrected guidance information that corrects the existence of the destination and / or alternative guidance information that guides users to an alternative landmark that can replace the destination, thereby increasing the reliability of the guidance.

[0047] In this embodiment, the alternative guidance information includes at least one of information on an alternative landmark different from the map landmark before the correction, road shape and / or road structure at the guidance point, and dynamic objects, which allows alternative guidance to be output in accordance with the characteristics of the guidance point.

[0048] In a modified example of this embodiment, when multiple substitute landmarks (substitute objects) are detected during alternative guidance, the controller 12 may evaluate the degree of deviation from the map landmark indicated in the landmark information for each of the multiple substitute landmarks, and provide guidance by including information on the substitute landmark with the lowest degree of deviation in the guidance information. The degree of deviation is an evaluation value that indicates the difference in information attribute with respect to the map landmark guided by advance guidance. The information attribute may be, alternative target The relative positions of alternative target Types of alternative target In other words, the deviation is shown by the color of the map target at the guide point. Things and The deviation degree is a value according to at least one element of the positional relationship with the alternative landmark, the positional relationship between the alternative landmark and the driving route at the guidance point, and the distance from the alternative landmark to the guidance point. The route guidance unit 16 may calculate the deviation degree according to the positional relationship between the position of the map landmark at the guidance point and the alternative landmark. When the position of the map landmark (hereinafter also referred to as the pre-correction landmark) guided by advance guidance and the position of the alternative landmark match, the deviation degree will be a low value, and the closer the position of the pre-correction landmark and the position of the alternative landmark are, the lower the deviation degree will be.

[0049] The route guidance unit 16 may calculate the deviation degree according to the positional relationship between the driving route and the alternative landmark at the guidance point. For example, in the case of a guidance route that requires a left turn at the guidance point, the deviation degree is lower for an alternative landmark that is located in a position that is easily visible to the driver on the route where the vehicle 1 turns left. For example, in the case of route guidance that requires entering an intersection from the south, turning left at the intersection, and heading west, it is assumed that the pre-correction landmark was located in the southwest of the intersection. In such a case, the deviation degree of an alternative landmark located in the southwest of the intersection is the smallest, the deviation degree of an alternative landmark located in the northwest is the second lowest, the deviation degree of an alternative landmark located in the southeast is the third lowest, and the deviation degree of an alternative landmark located in the northeast is the highest. The route guidance unit 16 may also calculate the deviation degree according to the distance from the alternative landmark to the guidance point. The route guidance unit 16 may reduce the deviation degree as the alternative landmark is closer to the guidance point.

[0050] When the type of landmark is the same between the pre-revision landmark and the alternative landmark, the deviation degree is low. For example, if the pre-revision landmark is a convenience store and the alternative landmark is a gas station, these landmarks are the same building and are the same type of structure, so the deviation degree is low. Then, the route guidance unit 16 evaluates the deviation degree for each of the multiple alternative landmarks, and then modifies the route guidance so that the revised route guidance includes the alternative landmark with the lowest deviation degree, and provides last-minute guidance. This reduces the driver's cognitive load caused by modifying the advance guidance, and enables revised route guidance (last-minute guidance). In addition, the deviation between the advance guidance and the revised route guidance (last-minute guidance) can be appropriately evaluated.

[0051] In a modified example of this embodiment, the controller 12 evaluates the driver's driving load and may not output modified guidance information if the driving load is higher than a predetermined threshold. The driving load is evaluated based on images captured by an in-vehicle camera, detected values ​​from a biometric sensor, etc. For example, if the driver's line of sight changes frequently in the captured image, the driving load is high. Furthermore, the higher the pulse rate detected by the biometric sensor, the higher the driving load. The driving load may also be evaluated based on the driving route or images captured by an exterior camera. For example, the driving load increases with the number of driving operations required on a route, and increases with the number of pedestrians and other vehicles around the vehicle. The route guidance unit 16 compares the driving load with a predetermined threshold and does not output modified guidance information if the driving load is higher than the predetermined threshold. In other words, if the driving load is high, providing new information to the driver through last-minute guidance may further increase the driving load. In a modified example, if the driving load is high, the driving load can be prevented from increasing by prohibiting last-minute guidance.

[0052] In a modification of this embodiment, the controller 12 may correct the guidance by outputting corrected guidance information that corrects the presence of a landmark when the distance from the current position of the vehicle 1 to the guidance point is less than a predetermined distance. Specifically, when the distance from the current position of the vehicle 1 to the guidance point is less than a predetermined distance, the route guidance unit 16 corrects the guidance information so that the guidance information includes corrected guidance information but does not include alternative guidance information. When the current position of the vehicle 1 is approaching the guidance point, if last-minute guidance is provided by including corrected guidance information and alternative guidance information in the guidance information, the amount of information becomes large, and there is a possibility that the driver will not be able to recognize the information. Therefore, when the vehicle is approaching the guidance point, last-minute guidance is provided with limited information. This can increase the reliability of the guidance. [Explanation of symbols]

[0053] 1...Vehicle 2...Position acquisition device 3...External sensor 4...In-vehicle sensor 5. Database 10...Guidance correction device 11… output Device 12...Controller 13…Information acquisition department 14...Target detection unit 15…Judgment section 16...Route guidance section

Claims

1. A guidance correction method executed by a controller for correcting guidance to a destination, comprising: The controller Obtaining a map landmark, which is a landmark at a guidance point requiring guidance, from a database that stores information about landmarks; outputting route guidance including the map landmark as advance guidance from a position away from the guidance point by a second distance longer than the first distance; using an on-board sensor to detect an object at a position the first distance away from the guidance point while the vehicle is traveling along the guided travel route; determining whether the map landmark for which route guidance has been performed in the advance guidance matches the object; When it is determined that the map landmark for which route guidance has been performed in the advance guidance does not match the object, the guidance information at the guidance point is corrected; A guidance correction method for outputting the corrected guidance information from a position that is less than the first distance away from the guidance point.

2. 2. The guidance correction method according to claim 1, wherein the corrected guidance information includes correction information correcting the existence of the map landmark and / or alternative guidance information providing guidance to an alternative landmark that replaces the map landmark.

3. 3. The method of claim 1, wherein the controller generates a message including the modified guidance information in response to a voice interface.

4. 3. The method for correcting guidance according to claim 2, wherein the alternative guidance information includes at least one of information on an alternative landmark different from the map landmark before correction, information on a road shape and / or road structure at the guidance point, and information on a dynamic object.

5. A guidance correction method executed by a controller for correcting guidance to a destination, comprising: The controller Obtaining a map landmark, which is a landmark at a guidance point requiring guidance, from a database that stores information about landmarks; using an on-board sensor to detect an object at a position a first distance away from the guidance point while the vehicle is traveling along the guided travel route; determining whether the map landmark matches the object; If it is determined that the map landmark does not match the object, modify the guidance information at the guidance point; outputting the corrected guidance information from a position that is less than the first distance away from the guidance point; detecting a plurality of candidate alternative landmarks different from the map landmark; evaluating a degree of deviation from the map target for each of the plurality of alternative targets; The guidance correction method, wherein the corrected guidance information includes information about the alternative landmark with the smallest degree of deviation.

6. 6. The guidance correction method according to claim 5, wherein the deviation degree is a value corresponding to at least one element of a positional relationship between the position of the map landmark at the guidance point and the alternative landmark, a positional relationship between the driving route at the guidance point and the alternative landmark, and a distance from the alternative landmark to the guidance point.

7. A guidance correction method executed by a controller for correcting guidance to a destination, comprising: The controller Obtaining a map landmark, which is a landmark at a guidance point requiring guidance, from a database that stores information about landmarks; using an on-board sensor to detect an object at a position a first distance away from the guidance point while the vehicle is traveling along the guided travel route; determining whether the map landmark matches the object; If it is determined that the map landmark does not match the object, modify the guidance information at the guidance point; outputting the corrected guidance information from a position that is less than the first distance away from the guidance point; Evaluate the driver's workload, The guidance correction method includes not outputting the corrected guidance information when the driving load is higher than a predetermined threshold.

8. The controller 2. A method for correcting guidance according to claim 1, wherein if the distance from the current position of the vehicle to said guidance point is equal to or shorter than a predetermined distance, corrected guidance information in which the existence of said map landmark has been corrected is output.

9. A guidance correction device including a controller that corrects guidance to a destination, The controller Obtaining a map landmark, which is a landmark at a guidance point requiring guidance, from a database that stores information about landmarks; outputting route guidance including the map landmark as advance guidance from a position that is a second distance away from the guidance point, the second distance being longer than the first distance; using an on-board sensor to detect an object at a position the first distance away from the guidance point while traveling along the guided travel route; determining whether the map landmark for which route guidance has been performed in the advance guidance matches the object; When it is determined that the map landmark for which route guidance has been performed in the advance guidance does not match the object, the guidance information at the guidance point is corrected; A guidance correction device outputs the corrected guidance information from a position that is less than the first distance away from the guidance point.