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 guidance correction method and a guidance correction device.

Background Art

[0002] Conventionally, a map information management device for managing map information has 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 the guidance route, acquires a captured image captured at the acquired position from an imaging unit, and generates difference information between the landmark information acquired from the captured image and the landmark information included in the map information of the position where it has been determined that an operation different from the guidance route has been performed, and updates the landmark information based on the difference information.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems 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 point of a landmark different from the actual one, only guidance based on the landmark information before the update is performed, and no guidance regarding the difference in the landmark is performed. Therefore, there is a problem of low reliability for 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 enhance the reliability of the guidance.

Means for Solving the Problems

[0006] The present invention solves the above problem by obtaining map targets from a database, detecting an object from a position a first distance away from a guidance point using a sensor while driving along a route, determining whether the map target matches the object, and if it is determined that the map target does not match the object, correcting the 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 drawing]

[0008] [Figure 1] This is a block diagram of a route guidance system including a guidance correction device according to an embodiment of the present invention. [Figure 2] This flowchart shows an example of a control procedure for executing the guidance modification method according to an embodiment of the present invention. [Figure 3] This flowchart shows an example of a control procedure for executing the guidance modification method according to an embodiment of the present invention. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, an example in which the guidance correction method and guidance correction device according to the present invention are applied to a route guidance system will be used for explanation.

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

[0011] The guidance correction device 10 outputs guidance information to the user during route guidance. This guidance information includes, for example, a map and the route from the user's current location to the destination. The guidance correction device 10 also outputs guidance information to the user, including the direction of travel at the guidance point, when the user is approaching a guidance point where route guidance is needed. Guidance points are locations where there are two or more possible routes, such as intersections, junctions, and highway interchanges. Even locations other than those with two or more possible routes can be set as guidance points if they are necessary to accurately guide the vehicle's direction of travel. In other words, the guidance correction device 10 can pre-determine and use locations that accurately guide the vehicle's direction of travel as guidance points. The user drives vehicle 1 according to the route guidance.

[0012] The position acquisition device 2 acquires the position information of vehicle 1 as the user's position information. The position acquisition device 2 acquires the position information of vehicle 1 from GPS satellites, for example. The position of vehicle 1 is expressed in terms of longitude and latitude. The position acquisition device 2 acquires position information from GPS satellites 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, equipped with an image sensor such as a CCD or CMOS. The external sensor 3 is not limited to an on-board camera; it may also be a distance measuring device such as a laser. The external sensor 3 acquires an ambient image of objects around the vehicle. Objects are landmarks in the surrounding environment around the vehicle. Objects include static and dynamic objects. Static objects include, for example, advertising signs, signs, stop lines, traffic lights, pedestrian crossings, traffic restrictions, street trees, buildings, and road structures. Road structures include bridges, tunnels, etc. Dynamic objects include, for example, other vehicles, motorcycles, bicycles, and pedestrians. Objects stored in the map data include, for example, landmarks such as convenience stores, restaurants, and gas stations. Objects not stored in the map data are dynamic objects such as, for example, other vehicles.

[0014] Furthermore, the external sensor 3 detects the direction in which objects exist around the user and the distance to those objects. For example, the external sensor 3 may be a millimeter-wave radar, laser radar, ultrasonic radar, or laser rangefinder. The surrounding environment information, including the surrounding environment detected by the external sensor 3, is output to the guidance correction device 10 at predetermined intervals.

[0015] The in-vehicle sensor 4 detects the user's state inside the vehicle. The in-vehicle sensor 4 may be, for example, a camera installed inside the vehicle 1, and may be a camera equipped with an image sensor such as a CCD or CMOS. The in-vehicle sensor 4 continuously captures user images, including the user's face. The in-vehicle sensor 4 may also detect the user's biometric information. The user's biometric information includes the user's heart rate, sweating, body temperature, and pulse.

[0016] Database 5 is a database that stores various types of information. Database 5 is a recording medium that stores information about landmarks, and it stores map information. Map information includes at least road information and information about map landmarks (landmark information). In the following explanation, landmarks stored in the database correspond to map landmarks. Road information includes the type of road (e.g., general road, toll road, etc.), and the locations of intersections, stop lines, traffic lights, and road signs. Landmarks are features that can serve as landmarks 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 the guidance points where guidance is needed. For example, when providing route guidance such as "Turn left at the intersection with the gas station," the gas station becomes the map landmark. Road information may also serve as landmark information. For example, if it is information about an intersection, it can serve as a map landmark for route guidance, such as "Turn right at the next intersection." Map information also includes location information for guidance points where guidance is needed.

[0017] The guidance correction device 10 provides route guidance to the user (occupant) to their destination and corrects the guidance information at each guidance point. The guidance correction device 10 comprises 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, external sensor 3, internal sensor 4, and database 5, generates the 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 their destination and correcting the guidance information at each guidance point.

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

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

[0020] As shown in FIG. 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 the cooperation of software and hardware for executing each process. In this embodiment, after dividing the functions of the controller 12 into four blocks, the functions of each functional block will be described. However, 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 target information from the database 5. The map information is used for calculating the driving route to the destination and identifying the target at the guidance point. When the route calculation to the destination is performed externally, the information acquisition unit 13 may acquire the information on the driving route including the destination information.

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

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

[0024] During traveling on the driving route, the target detection unit 14 uses the vehicle exterior sensor 3 to detect an object at a position separated from the guidance point by a first distance. The object is a feature that can be a target in route guidance and represents a feature existing in the actual driving environment. In this embodiment, the target detected by the vehicle exterior sensor 3 is referred to as an "object". The object corresponds to a map target and is a target such as a convenience store, a restaurant, a gas station, etc. The object may also be a target indicated by road information. The first distance is a distance determined in advance according to the distance at which the vehicle exterior sensor 3 can detect an object. For example, if the vehicle-mounted sensor 3 is a vehicle-mounted camera, the first distance corresponds to the imaging range of the vehicle-mounted camera or a distance shorter than the distance corresponding to the imaging range of the vehicle-mounted camera. That is, when the vehicle 1 is at a position separated from the guidance point by the first distance, the vehicle-mounted camera can capture an object at the guidance point. The route guidance unit 16 described later calculates the driving route to the destination and sets a guidance point that requires guidance for the calculated driving route. In the following description, an embodiment mainly applying a vehicle-mounted camera as an example of the vehicle exterior sensor 3 will be described, but a distance measuring device may be used instead of the vehicle-mounted 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 target detection unit 14 acquires route guidance information, including guidance points, from the route guidance unit 16, and refers to map information to identify the location of the guidance points indicated in the route guidance information and the location of map targets at the guidance points. The route guidance information includes information on the driving route to the destination, information on guidance points that require guidance when driving along the driving route, and information on map targets at the guidance points. The target detection unit 14 measures the distance from the vehicle's current position to the next guidance point. When the measured distance reaches the first distance, it acquires an image captured by the on-board camera. The acquired image can be an image taken at the time the measured distance reaches the first distance, or at the time immediately before the measured distance reaches the first distance. The target detection unit 14 then detects a target image captured at the guidance point identified from the route guidance information from the captured image.

[0026] The determination unit 15 determines whether the map target matches the object. The determination unit 15 determines whether the map target at the guidance point, identified from the route guidance information, matches the object detected by the target detection unit 14 using the external sensor 3. Whether or not the map target actually exists at the guided location.The determination is made based on the detection results of the target object using the captured image. For example, let's assume that the route guidance information indicates "Turn left at the intersection with the convenience store." The target object 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 target indicated in the route guidance information matches the object detected by the target object detection unit 14. The determination of whether the map target matches the object also includes the position. When the route guidance is "Turn left at the intersection with the convenience store," if the capture image can detect that a convenience store is located at the intersection, the determination unit 15 determines that the object exists at the guidance point. On the other hand, if it can detect that a convenience store is not located at the intersection, or if it cannot detect that a convenience store is located at the intersection, the determination unit 15 determines that the object does not exist at the guidance point. Then, since the object does not exist at the guidance point, the determination unit 15 determines that the map target does not match the object. Furthermore, if the determination unit 15 detects that there is a landmark other than a convenience store at the intersection, it will determine that the map landmark does not match the object based on the difference between the map landmark's position and the object's position. However, regarding the determination of whether the positions match, if the difference in position is within a predetermined range set according to the detection error, the determination unit 15 may determine that the positions match.

[0027] The route guidance unit 16 provides route guidance so that vehicle 1 travels along a route from its current location to its destination. When the route guidance unit 16 obtains the current location of vehicle 1 and the destination of vehicle 1, it refers to the map information stored in the database 5 and generates a route from the current location of vehicle 1 to its destination. The route guidance unit 16 uses the location information obtained by the location acquisition device 2 as the current location of vehicle 1. The route guidance unit 16 also uses the destination information entered by the user as the destination of vehicle 1. The route may include routes that pass through multiple destinations. The route guidance unit 16 displays the map, route, current location of vehicle 1, etc., to the user on the screen via the output device 11.

[0028] Furthermore, the route guidance unit 16 extracts guidance points located along the driving route based on the route information and map information of the driving route. When vehicle 1 starts driving along the driving route, the route guidance unit 16 acquires the current position of vehicle 1 at regular intervals and determines whether vehicle 1 is approaching a guidance point based on the current position of vehicle 1 and the position of the guidance point on the driving route. If vehicle 1 is approaching a guidance point, the route guidance unit 16 causes the output device 11 to output guidance information for the guidance point. For example, the route guidance unit 16 may output the generated guidance information to the output device 11 as audio, or it may display text or icons such as arrows on the screen indicating the direction the user should go.

[0029] The route guidance unit 16 provides route guidance at the guidance point in two stages: pre-guidance and immediate guidance. Pre-guidance is provided when the driver cannot see the guidance point and is performed at a position a second distance away from the guidance 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, pre-guidance is performed at a position so far away that the external sensor 3 cannot image the guidance point. The route guidance unit 16 provides the user with pre-guidance information that includes information on the remaining distance to the guidance point, information on landmarks at the guidance point, and information on driving operations at the guidance point. The landmark information used in the pre-guidance is the map landmark information stored in the database 5. This makes it possible to provide route guidance that prompts the driver to prepare in advance. In the pre-guidance, a message such as "Approximately 300m ahead, turn left at the intersection with a convenience store." is output. With such pre-guidance, the driver can confirm the landmark before actually seeing the convenience store and prepare for driving operations.

[0030] The last-minute announcement is given after the advance announcement and is given at the same location as the advance announcement. DriverThe guidance is given from a position less than 1 distance away from the guidance point to the guidance point. The immediate guidance is given when the driver is close enough to see the guidance point, and is given within a range in which the guidance point can be imaged by the external sensor 3. The route guidance unit 16 provides the user with immediate guidance, including information on targets at the guidance point and driving operation information at the guidance point in the guidance information. The information on targets used in immediate guidance is destination information detected by the external sensor 3. In immediate guidance, a message such as "You will soon turn left at the intersection with a convenience store" is output. Upon hearing the immediate guidance message, the driver can confirm the presence of the target (convenience store) assumed in the prior guidance at the intersection that is visible to them, and confirm that the guidance point is just ahead.

[0031] As described above, pre-guided targets are identified from target information stored in the database, while immediate pre-guided targets (objects) are detected from images captured by the in-vehicle camera. Therefore, if the map information is not updated in time, the map targets recorded in the database may differ from the actual objects detected from the in-vehicle camera images. In addition, for example, obstacles near the target (e.g., trees or buildings other than the target) may prevent the in-vehicle camera from capturing the object, and the driver may not be able to see the map targets used in the pre-guided directions.

[0032] In this embodiment, the determination unit 15 compares the map target used in the pre-guidance with the object detected near the guidance point during the immediate guidance, and determines from the comparison result whether the map target used in the pre-guidance matches the object. That is, the determination unit 15 performs the determination of whether the map target matches the object on the target that has already been guided in the pre-guidance. If it is determined that the target used in the pre-guidance does not match the object, the route guidance unit 16 corrects the guidance information for the guidance point and performs immediate guidance using the corrected guidance information. On the other hand, if it is determined that the target used in the pre-guidance matches the object, the route guidance unit 16 performs immediate guidance without correcting the route guidance at the guidance point.

[0033] The correction of guidance information by the route guidance unit 16 is a correction of information related to landmarks, or in other words, a correction of the content used to guide the user to their destination. The guidance information corrected by the route guidance unit 16 may include corrected guidance information that corrects the existence of a landmark, and / or alternative guidance information that replaces the landmark. For example, let's consider a case where the route guidance unit 16 outputs a message in the pre-guidance such as "Approximately 300m ahead, turn left at the intersection with a convenience store," but there is actually no "convenience store." In such a case, the route guidance unit 16 will issue a corrected guidance message such as "There was no convenience store, was there?" which indicates that the map landmark used in the pre-guidance does not exist at the guidance point. In other words, the corrected guidance information is information to correct the existence of the landmark indicated in the pre-guidance.

[0034] Alternative guidance is guidance that differs in content from pre-guidance and helps the driver identify the guidance point. Alternative guidance information only needs to include at least one piece of information from the following: an alternative landmark different from the map landmark before the correction, road shape and / or road structure at the guidance point, and dynamic objects. The map landmark before the correction is the landmark used in the pre-guidance. For example, let's explain using the example where the previous guidance before the correction output a message such as "Turn left at the intersection with the 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 with the convenience store" as alternative guidance information. In this way, a different 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 signalized intersection" as alternative guidance information. In this way, the road shape and road structure present at the guidance point are used for alternative guidance. As yet another example of alternative guidance, if a dynamic object is detected by the external sensor 3 at or around the guidance point, the route guidance unit 16 outputs a message such as "Follow the car in front" as alternative guidance information. In this way, the dynamic object is used for alternative guidance. Inside information When correcting the report, the guidance regarding the target object is corrected without changing the driving route. Driving You may modify the route.

[0036] Then, the route guidance unit 16 corrects the guidance information to the destination in the manner described above, and outputs the corrected guidance information from a position less than 1 distance away from the guidance point. This prevents discrepancies between the driver's perception, which was prepared based on the pre-guidance, and the actual situation at the guidance point that the driver sees, in cases where the map target used in the pre-guidance does not match the object.

[0037] Furthermore, when the route guidance unit 16 outputs a message indicating a correction, it may generate a message with 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 prior guidance, an apology, a friendly expression, etc. This allows the impression of the output content to be adapted according to the nature of the voice interface.

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

[0039] When vehicle 1 starts traveling along the designated route, controller 12 begins the control flow from step S1. In step S1, information acquisition unit 13 acquires information on the current position of vehicle 1 from position acquisition device 2. Information acquisition unit 13 also acquires information from external sensor 3 and internal sensor 4. In step S2, route guidance unit 16 determines whether vehicle 1's current position has reached the pre-guided position. The pre-guided position is a position two distances away from the guidance point. If vehicle 1's current position has not reached the pre-guided position, controller 12 returns to the control flow of step S1 and executes the control flow from step S1 onward.

[0040] In step S3, the route guidance unit 16 retrieves target information from the database and identifies map targets at guidance points along the travel route. In step S4, the route guidance unit 16 provides advance guidance using the map targets identified from the target information in the database 5. Then, the controller 12 terminates the control flow shown in Figure 2.

[0041] Next, the control procedure for the guidance correction method performed by the guidance correction device 10 will be explained using Figure 3. Figure 3 is a flowchart showing an example of the control procedure for performing the guidance correction method according to this embodiment. The control flow in Figure 3 is the control flow when performing immediate guidance. The control flow in Figure 3 is performed after the prior guidance.

[0042] In step S11, the information acquisition unit 13 acquires information on the current position of vehicle 1 from the position acquisition device 2. The information acquisition unit 13 also acquires information from the external sensor 3 and the internal sensor 4. In step S12, the route guidance unit 16 determines whether the current position of vehicle 1 has reached the previous guidance position. The previous guidance position is a position a distance of 1 from the guidance point. If the current position of 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 target. The map target is a map target used in the pre-guidance and corresponds to a target identified from the target information in the database 5.

[0043] In step S14, the target detection unit 14 uses the external sensor 3 to detect an object from a position a distance of 1 from the guidance point while the vehicle is traveling along the guided route. In step S15, the determination unit 15 determines whether the map target matches the object. If it is determined that the map target does not match the object, the route guidance unit 16 corrects the guidance information. Then, in step S17, the route guidance unit 16 provides immediate guidance by outputting the corrected guidance information from a position less than 1 distance from the guidance point. On the other hand, if it is determined that the target exists at the guidance point, the route guidance unit 16 does not correct the guidance information and provides immediate guidance in step S17. Then, the controller 12 terminates the control flow shown in Figure 3.

[0044] As described above, the guidance correction method and guidance correction device 10 according to this embodiment acquire a map target object, which is a target object at a guidance point requiring guidance, from a database 5 that stores information about target objects. While driving along the driving route guided by the route guidance, the external sensor (onboard sensor) 3 detects an object from a position a first distance away from the guidance point, determines whether the map target object matches the object, and if it is determined that the map target object does not match the object, corrects the guidance information at the guidance point and outputs the corrected guidance information from a position less than the first distance away from the guidance point. This enables appropriate guidance when a target object identified from the database record information does not actually exist at the guidance point. As a result, the reliability of the guidance can be increased.

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

[0046] Furthermore, in this embodiment, the corrected guidance information includes corrected guidance information that corrects the existence of the destination, and / or alternative guidance information that guides the user to an alternative target instead of the destination. This makes it possible to increase the reliability of the guidance.

[0047] In this embodiment, the alternative guidance information includes at least one piece of information from among the following: an alternative target different from the map target before modification, the road shape and / or road structure at the guidance point, and dynamic objects. This makes it possible to output alternative guidance that is in line with the characteristics of the guidance point.

[0048] In a modified version of this embodiment, when the controller 12 detects multiple alternative targets (alternative objects) during alternative guidance, it may evaluate the degree of deviation from the map target indicated by the target information for each of the multiple alternative targets, and include information about the alternative target with the lowest degree of deviation in the guidance information before providing guidance. The degree of deviation is an evaluation value that indicates the difference in information attributes with respect to the map target guided by prior guidance. The information attributes are, alternative target Positional relationship, alternative target Types alternative target This is indicated by colors, etc. In other words, the degree of deviation is the map target at the guide point. Things and The value corresponds to at least one of the following elements: the positional relationship with the alternative target, the positional relationship between the driving route at the guidance point and the alternative target, and the distance from the alternative target to the guidance point. The route guidance unit 16 may calculate the degree of deviation according to the positional relationship between the map target and the alternative target at the guidance point. If the position of the map target guided by prior guidance (hereinafter also referred to as the pre-correction target) and the position of the alternative target are the same, the degree of deviation will be a low value, and the closer the positions of the pre-correction target and the alternative target are, the lower the degree of deviation will be.

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

[0050] When the type of target is the same between the original target and the alternative target, the degree of deviation will be low. For example, if the original target is a convenience store and the alternative target is a gas station, these targets are the same building and of the same type, so the degree of deviation will be low. The route guidance unit 16 then evaluates the degree of deviation for each of the multiple alternative targets, and then modifies the route guidance so that the modified route guidance includes the alternative target with the lowest degree of deviation, and provides immediate guidance. This reduces the cognitive load on the driver caused by modifying the prior guidance and allows for the provision of modified route guidance (immediate guidance). Furthermore, it allows for appropriate evaluation of the deviation between the prior guidance and the modified route guidance (immediate guidance).

[0051] In a modified version of this embodiment, the controller 12 evaluates the driver's driving load, and if the driving load is higher than a predetermined threshold, it does not need to output corrected guidance information. The driving load is evaluated from images captured by the in-vehicle camera, detected values ​​from a biosensor, etc. For example, if the driver's gaze direction changes frequently from the captured images, the driving load is high. Also, the more pulses detected by the biosensor, the higher the driving load. The driving load may also be evaluated from the driving route or images captured by the external camera. For example, the driving load is higher for routes that involve many driving operations, and the driving load is higher if there are many pedestrians or other vehicles around the vehicle. The route guidance unit 16 compares the driving load with a predetermined threshold that has been set in advance, and if the driving load is higher than the predetermined threshold, it does not output corrected guidance information. In other words, if the driving load is high, providing new information to the driver through immediate guidance may further increase the driving load. In the modified version, if the driving load is high, the increase in the driving load can be prevented by prohibiting immediate guidance.

[0052] Furthermore, in a modified version of this embodiment, the controller 12 may correct the guidance by outputting corrected guidance information that corrects the presence of a target object when the distance from the vehicle 1's current position to the guidance point is less than or equal to a predetermined distance. Specifically, 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 distance from the vehicle's current position to the guidance point is less than or equal to a predetermined distance. If the vehicle 1's current position is approaching the guidance point and corrected guidance information and alternative guidance information are included in the guidance information for immediate guidance, the amount of information will be large, and the driver may not be able to recognize the information. Therefore, when approaching the guidance point, the information is limited and immediate guidance is provided. This can improve the reliability of the guidance. [Explanation of Symbols]

[0053] 1…Vehicle 2...Position acquisition device 3…External vehicle sensors 4…In-car sensors 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 to correct guidance to a destination, The aforementioned controller, From a database that stores information about target objects, the map target object, which is the target object at the guidance point requiring guidance, is obtained. From the aforementioned guidance point, a route guidance including the aforementioned map target object is output as advance guidance from a position a second distance away, which is longer than the first distance. While driving along the guided route, an object is detected from a position a distance of the first distance from the guide point using an on-board sensor. In the aforementioned prior guidance, it is determined whether the map target object for which route guidance has been provided matches the object. If it is determined that the map target object for which route guidance was provided in the prior guidance does not match the object, the guidance information at the guidance point will be corrected. A guidance correction method that outputs the corrected guidance information from a location less than the first distance away from the aforementioned guidance point.

2. The method for correcting directions according to claim 1, wherein the corrected directions include corrected directions that correct the existence of the map target object, and / or alternative directions that guide to an alternative target object that replaces the map target object.

3. The guidance modification method according to claim 1 or 2, wherein the controller generates a message containing the modified guidance information in response to the voice interface.

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

5. A guidance correction method executed by a controller to correct guidance to a destination, The aforementioned controller, From a database that stores information about target objects, the map target object, which is the target object at the guidance point requiring guidance, is obtained. While driving along the guided route, an object is detected using an on-board sensor at a distance of 1 from the guide point. Determine whether the aforementioned map target matches the aforementioned object. If it is determined that the aforementioned map target does not match the aforementioned object, the guidance information at the guidance point is corrected. The corrected guidance information is output from a position less than the first distance away from the aforementioned guidance point. Multiple alternative target candidates other than the aforementioned map target are detected, For each of the multiple candidate alternative targets, the degree of deviation from the map target is evaluated. The modified guidance information includes a guidance modification method that includes information about the alternative target with the lowest degree of deviation.

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

7. The aforementioned controller, Evaluate the driver's workload, The guidance correction method according to claim 1 or 5, wherein the modified guidance information is not output when the operating load is higher than a predetermined threshold.

8. The aforementioned controller, The guidance correction method according to claim 1, which outputs corrected guidance information that corrects the existence of the map target object when the distance from the vehicle's current position to the guidance point is less than or equal to a predetermined distance.

9. A guidance correction device equipped with a controller for correcting guidance to a destination, The aforementioned controller, From a database that stores information about target objects, the map target object, which is the target object at the guidance point requiring guidance, is obtained. From the aforementioned guidance point, a route guidance including the aforementioned map target object is output as advance guidance from a position a second distance away, which is longer than the first distance. While driving along the guided route, an object is detected from a position a distance of the first distance from the guide point using an on-board sensor. In the aforementioned prior guidance, it is determined whether the map target object for which route guidance has been provided matches the object. If it is determined that the map target object for which route guidance was provided in the prior guidance does not match the object, the guidance information at the guidance point will be corrected. A guidance correction device that outputs the corrected guidance information from a position less than the first distance away from the guidance point.

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