Navigation device

Abstract

The invention relates to a navigation device. The present disclosure makes the guidance of the navigation device more easily understood in feeling. This navigation device is mounted on a vehicle and guides a travel path of the vehicle. The navigation device includes a position information acquisition unit, a storage unit, an output unit that outputs information to a user, and a control unit. The position information acquisition unit acquires a current position of the vehicle. The storage unit stores map information. The control unit extracts a guidance point on the route on the basis of the current position and map information, estimates a predicted time to be taken until the guidance point is reached, and causes the output unit to output the predicted time.

Description

Technical Field

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

[0002] A vehicle guidance device is disclosed, which is configured to provide information guidance to a destination or a route change point through sensory expressions such as "still far away" and "just a little bit closer" instead of providing information guidance based on the remaining distance (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 8-35847

[0006] When a sensory representation is used to guide the user, each person's perception varies, and such a representation may not match the user's perception. In addition, guidance based on the remaining distance may sometimes be difficult to understand intuitively. Summary of the invention

[0007] The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to make guidance by a navigation device easier to understand sensorily.

[0008] A navigation device according to an embodiment of the present disclosure that solves the above-mentioned problem is a navigation device that is mounted on a vehicle and guides the vehicle's travel route, wherein the navigation device comprises: a position information acquisition unit that acquires the vehicle's current position; a storage unit that stores map information; an output unit that outputs information to a user; and a control unit that extracts a guidance point on the route based on the current position and the map information, estimates a predicted time to arrive at the guidance point, and causes the output unit to output the predicted time.

[0009] Effects of the Invention

[0010] According to the present disclosure, a navigation device can be provided which, when providing route guidance, uses the time required to reach the guidance point to convey the guidance point on the route in a manner that is easy to grasp by sense. Thus, the guidance of the navigation device can be made easier to understand by sense. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a block diagram showing a schematic configuration of a navigation device according to one embodiment of the present disclosure.

[0012] Figure 2 Yes means Figure 1 A functional block diagram showing a schematic structure of a control unit.

[0013] Figure 3 Yes through Figure 1 FIG. 2 is a diagram for explaining an example of guidance of a guidance location by a navigation device.

[0014] Figure 4 Yes means Figure 1 A flowchart of an example of a process executed by a control unit.

[0015] Description of reference numerals:

[0016] 10: Navigation device;

[0017] 11: Ministry of Communications;

[0018] 12: Storage unit;

[0019] 13: Positioning unit (position information acquisition unit);

[0020] 14: Input unit;

[0021] 15: output unit;

[0022] 16: Control unit;

[0023] 16a: destination acquisition unit;

[0024] 16b: path setting unit;

[0025] 16c: guidance location extraction unit;

[0026] 16d: Time prediction department;

[0027] 16e: accuracy estimation unit;

[0028] 16f: Report judgment department;

[0029] 16f: Report content generation department;

[0030] 16e: Speech Synthesis Department;

[0031] 17: Display;

[0032] 18: Speaker;

[0033] 20: Network;

[0034] 30: Server. DETAILED DESCRIPTION

[0035] Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the drawings used in the following description are schematic. The dimensions and proportions on the drawings are not necessarily consistent with the dimensions and proportions in reality.

[0036] (System Overview)

[0037] The navigation device 10 of one embodiment of the present disclosure is a device that is mounted on a vehicle and displays a map to a user who is a passenger of the vehicle, and guides the user on the route to the destination. The vehicle includes a passenger car, a truck, a bus, a large / small special vehicle, etc., but is not limited to these vehicles. The vehicle includes various types of vehicles that will be realized in the future. For example, the vehicle may include an autonomous driving vehicle, an amphibious vehicle, and an air-land amphibious vehicle.

[0038] like Figure 1 As shown, the navigation device 10 may be configured to be able to communicate with various servers 30 outside the vehicle via a communication network 20. The communication network 20 includes the Internet, VPN (Virtual Private Network), and a mobile communication network.

[0039] The server 30 can provide traffic information to the navigation device 10. The server 30 includes servers of government agencies responsible for traffic management, road managers, and providers of traffic information. The server 30 can provide road congestion information, jam information, accident information, etc. In addition, the server 30 can also include a server that provides road map information.

[0040] (Construction of a navigation device)

[0041] The navigation device 10 includes a communication unit 11 , a storage unit 12 , a positioning unit 13 , an input unit 14 , an output unit 15 , and a control unit 16 .

[0042] The communication unit 11 can be connected to the communication network 20 through a wireless communication unit to obtain information from the server 30. The wireless communication unit includes the fourth generation mobile communication system (4G), the fifth generation mobile communication system (5G), Wi-Fi (registered trademark) and WiMAX (Worldwide Interoperability for Microwave Access). The communication unit 11 can also correspond to dedicated short range communication (DSRC: Dedicated Short Range Communication) and the like. In addition, the communication unit 11 can be configured to provide services that can receive traffic information using broadcast waves such as FM (frequency modulation) multiplex broadcasting.

[0043] The storage unit 12 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or any combination thereof. The semiconductor memory is, for example, a RAM (random access memory) or a ROM (read only memory). The RAM is, for example, an SRAM (static random access memory) or a DRAM (dynamic random access memory). The ROM includes, for example, an EEPROM (electrically erasable programmable read only memory). The magnetic memory may include, for example, a hard disk. The optical memory may include, for example, a CD (Compact Disc), a DVD (Digital Versatile Disc), and a BD (Blu-ray (registered trademark) Disc). The storage unit 12 functions, for example, as a main storage device, an auxiliary storage device, or a cache memory. The storage unit 12 stores programs executed by the control unit 16, data used in the operation of the control unit 16, and data obtained by the operation of the control unit 16.

[0044] The storage unit 12 can store road map information. The road map information is configured to include road network information, background map information, facility information, etc. The road network information expresses the connection and shape of roads through points called nodes and lines called links. Nodes and links determine location information by latitude and longitude. Background map information includes information on the shape of land, buildings, rivers, and railway routes in the background of the road. Facility information is information related to facilities included in the road map. The storage unit 12 can always store road map information. The storage unit 12 can also temporarily store road map information read from the server 30 that provides the road map via the communication unit 11 as needed.

[0045] The positioning unit 13 detects the position of the vehicle equipped with the navigation device 10. The positioning unit 13 functions as a position information acquisition unit. The position detected by the positioning unit 13 can be set to a position represented by latitude, longitude, etc. The positioning unit 13 can include a receiver corresponding to a global positioning system (GNSS: Global Navigation Satellite System) using artificial satellites. The receiver corresponding to the GNSS includes a GPS (Global Positioning System: Global Positioning System) receiver. The signal from the GPS receiver can be used to obtain the latitude and longitude information of the current position of the vehicle. The signal from the GPS receiver can be combined with various detection devices such as an azimuth sensor, a steering angle sensor, and a distance sensor. In this way, it is possible to improve the accuracy of position detection and estimate the position at a place where the radio waves from the satellite cannot reach. It should be noted that a receiver corresponding to other GNSS can be used instead of a GPS receiver, or a receiver corresponding to other GNSS can be used in addition to a GPS receiver. As other GNSS, there are, for example, GLONASS (GLONASS Satellite Navigation System), Galileo (Galileo Satellite Navigation System), Compass (Beidou Satellite Navigation System), and a satellite positioning system using a quasi-zenith satellite.

[0046] The input unit 14 receives input to the navigation device 10. The input unit 14 may include a touch panel formed integrally with the display 17 described later and a microphone that receives voice-based input. The touch panel is a device that senses input through contact by a user. The touch panel receives input in conjunction with the display content of the display 17. As a touch panel, various types of touch panels are included, such as an electrostatic capacitance type, a resistive film type, and a surface elastic wave type. The microphone converts the input voice into a voice signal and outputs it. In order to convert the voice signal output by the microphone into text, the navigation device 10 may be configured to perform voice recognition processing in the control unit 16 or the like. The input unit 14 may further include a connector that receives input from an external input device.

[0047] The output unit 15 outputs information processed by the navigation device 10 to the user. The output unit 15 includes a display 17 and a speaker 18. The display 17 and the speaker 18 may be shared by other devices in the vehicle. The output unit 15 may include a connector for outputting information to the display 17, the speaker 18, and other output devices.

[0048] The display 17 is a device that displays an image based on an image signal obtained as a result of processing by the control unit 16. The display 17 can be, for example, a liquid crystal display (LCD: Liquid Crystal Display), an organic EL (Electro-Luminescence: Electroluminescence) display, an inorganic EL display, a plasma display panel (PDP: Plasma Display Panel) or other various displays. In addition, the display 17 can also be a head-up display (HUD: Head Up Display). The HUD can project the display image on the front windshield or on the combiner arranged on the instrument panel.

[0049] The speaker 18 converts the voice signal into physical vibration and generates sound in the space. The speaker 18 can use a speaker for sound provided in the vehicle. The speaker 18 can be arranged on a door, a dashboard, a pillar, etc. of the vehicle. A known general speaker can be used as the speaker 18.

[0050] The control unit 16 includes at least one processor, at least one programmable circuit, at least one dedicated circuit, or any combination thereof. The processor is a general-purpose processor such as a CPU (central processing unit) or a GPU (graphics processing unit), or a dedicated processor specifically used for specific processing. The programmable circuit is, for example, an FPGA (field-programmable gate array). The dedicated circuit is, for example, an ASIC (application specific integrated circuit).

[0051] The control unit 16 controls each unit of the navigation device 10 and executes various calculation processes related to the operation of the navigation device 10. The control unit 16 operates each unit of the navigation device 10 to allow the navigation device 10 to function.

[0052] (Configuration of the control unit)

[0053] In one embodiment, if Figure 2 As shown, the control unit 16 includes a destination acquisition unit 16a, a route setting unit 16b, a guidance location extraction unit 16c, a time prediction unit 16d, an accuracy estimation unit 16e, a report determination unit 16f, a report content generation unit 16g, and a speech synthesis unit 16h. These units can be either hardware modules or software modules. These units can be integrated with each other and / or divided into multiple units. The processing performed by each unit of the control unit 16 can be said to be the processing performed by the control unit 16.

[0054] The destination acquisition unit 16a acquires information of the destination from the user via the input unit 14. The destination acquisition unit 16a can provide a function of searching for the destination from the road map information stored in the storage unit 12 so that the user can easily input the destination. The destination can be searched using, for example, the address and telephone number of the facility included in the facility information of the road map information.

[0055] The route setting unit 16b can search for a route from the current position detected by the positioning unit 13 to the destination acquired by the destination acquisition unit 16a based on the road map information stored in the storage unit 12. The route setting unit 16b can extract a plurality of routes and present them on the display 17. Alternatively, the user can select a route from the plurality of routes. The route setting unit 16b sets the route selected by the user as the route to the destination. In the case where the user requests a re-search of the route or in the case where the vehicle equipped with the navigation device 10 deviates from the set route, the route setting unit 16b can re-search the route and reset it.

[0056] The guide location extraction unit 16c extracts the guide location that is the object of reporting the predicted time to be spent until the user arrives. The guide location is a point on a set path. The guide location includes, for example, an intersection where a right turn or a left turn is made on the path, or a branch point that branches to the left or right. In addition, the guide location may include a location with a landmark on the path and a location with facilities related to road traffic. The landmark may include a famous building, a bridge, and a station. Facilities related to road traffic may include, for example, a gas station and a drive-in. Moreover, the guide location may include a destination.

[0057] The guide point extraction unit 16c can extract the next guide point on the route based on the current position. The guide point extraction unit 16c extracts the next guide point, for example, when the previous guide point is passed. The guide point extraction unit 16c can extract the guide points after the next guide point based on a preset condition or based on an instruction from the user via the input unit 14.

[0058] The time prediction unit 16d predicts the time it will take until the vehicle equipped with the navigation device 10 reaches the guidance location. The time predicted by the time prediction unit 16d is called the predicted time. For example, the time prediction unit 16d calculates the distance from the current position to the guidance location based on the road map information. The time prediction unit 16d can calculate the time it will take to travel the distance to the guidance location at the predicted speed of the vehicle equipped with the navigation device 10. The time prediction unit 16d can use the most recent average speed of the actual vehicle as the predicted speed. The average speed just before can be set as the average speed from the current time point to the current time point before a predetermined time. In addition, the time prediction unit 16d can also set the speed limit of the path on which the vehicle is traveling as the predicted speed. It should be noted that the actual speed of the vehicle can be calculated by the control unit 16 based on the change of the current position detected by the positioning unit 13. Alternatively, the control unit 16 can also obtain speed information measured for the speedometer from the vehicle equipped with the navigation device 10.

[0059] When the time prediction unit 16d acquires traffic information indicating a congestion condition on the route to be traveled from the server 30 via the communication unit 11, the time prediction unit 16d may estimate the predicted time by taking into account the traffic information. For example, when the traffic information includes information indicating the level of congestion on the route, the time prediction unit 16d estimates the average travel speed in the congested section and uses the average travel speed for calculating the predicted time. When a serious congestion occurs on the route or an accident occurs, the time prediction unit 16d may determine that the predicted time cannot be calculated.

[0060] When there is a traffic light on the route, the time prediction unit 16d may calculate the average waiting time based on the interval of the traffic light switching and use it to calculate the predicted time. The time prediction unit 16d may use the standard switching time of the traffic light as the switching time of the signal. Alternatively, the time prediction unit 16d may be configured to store the switching time of the individual signal in the storage unit 12 or obtain the switching time of the individual signal from the server 30. In addition, the time prediction unit 16d may consider right turns, left turns, temporary stops, etc. on the route as factors affecting the predicted time.

[0061] The accuracy estimation unit 16e evaluates the prediction accuracy of the predicted time taken until the guidance location is reached. Various methods can be used in the evaluation method of prediction accuracy. For example, the accuracy estimation unit 16e estimates the error rate of the predicted time as the prediction accuracy. The error rate can be set as the ratio of the estimated value of the error of the predicted time to the predicted time. That is, the error rate is calculated by the following formula.

[0062] Error rate = estimated value of error in prediction time / prediction time

[0063] For example, the accuracy estimation unit 16e extracts factors that cause errors in the predicted time on the path, and digitizes and sums up the errors estimated thereby. For example, path congestion becomes a factor that causes errors in the predicted time. The accuracy estimation unit 16e calculates the error in the predicted time corresponding to the congestion condition. The error in the predicted time corresponding to the congestion condition can be determined based on information that has been stored in the storage unit 12 or the external server 30 in the past. In addition, in the case of a traffic light, the timing of switching the traffic light may cause a prediction error. For example, the accuracy estimation unit 16e can add the difference between the average traffic light waiting time and the maximum traffic light waiting time and the estimated value of the error in the predicted time. In addition, when turning right, turning left, and stopping temporarily on the path, there are individual differences in the way of deceleration and acceleration at the locations where these behaviors are performed, so errors will be generated in the predicted time. Therefore, the accuracy estimation unit 16e adds the estimated value of the error in the predicted time according to the number of these locations.

[0064] The report determination unit 16f determines whether to report the predicted time to the user. In one embodiment, the report determination unit 16f may determine not to report the predicted time when the predicted time is shorter than the specified time. The specified time is, for example, 10 seconds, 20 seconds, or 30 seconds, but is not limited to these times. The report determination unit 16f may also determine not to report based on the distance to the guidance location instead of the predicted time. When the distance to the guidance location is short, the time to arrive at the guidance location may vary significantly due to the vehicle slowing down before the guidance location. Therefore, there is sometimes a deviation between the predicted time and the time when the vehicle actually arrives at the guidance location. Therefore, if the predicted time is reported to the user just before the guidance location, misunderstanding or confusion will occur instead. By not reporting the predicted time, the control unit 16 can avoid the occurrence of misunderstandings or confusions such as those described above.

[0065] In addition, in one embodiment, when it is determined that the time prediction unit 16d cannot calculate the predicted time during the process of calculating the predicted time, the report determination unit 16f may also determine not to report the predicted time. Therefore, when there is severe congestion on the route or when an accident occurs, the predicted time is not reported. In this way, it is possible to avoid reporting a low-reliability predicted time to the user when the predicted accuracy of the arrival time at the guidance location is considered to be extremely low.

[0066] The report determination unit 16f may determine to report the predicted time when the error rate estimated by the accuracy estimation unit 16e is less than or equal to a predetermined threshold, and determine not to report the predicted time when the error rate exceeds the predetermined threshold. The predetermined threshold may be set to 0.1, 0.2, or 0.3, for example. That is, if the estimated accuracy of the predicted time is high, the accuracy estimation unit 16e determines to report the predicted time, and if the estimated accuracy of the predicted time is low, the accuracy estimation unit 16e determines not to report the predicted time. Thus, the navigation device 10 can report only the predicted time with high reliability to the user.

[0067] The report content generating unit 16g generates the content of the report to the user using the predicted time predicted by the time prediction unit 16d. The report content includes the following message: "Go straight ahead T 1 Minutes. ","Go straight ahead to P 1 . to P 1 About T 2 Minutes. " and "T 3 seconds to the right turn location”, etc. Among them, T 1 To T 3 Indicates time, P 1 Indicates the name of a place. When the notification determination unit 16f determines that the predicted time is not to be reported, the notification content generation unit 16g may generate notification content that reports the distance to the guidance point.

[0068] The speech synthesis unit 16h performs speech synthesis processing to provide a speech signal to the speaker 18. The speech synthesis processing is a process of generating a human voice based on the text of the report content generated by the report content generation unit 16g. As a technology for performing speech synthesis, a well-known technology such as a waveform connection type speech synthesis method and a statistical model type synthesis method can be used. The speech synthesis unit 16h outputs a speech signal to the speaker 18, whereby the user can know the estimated time it will take to reach the guidance location through the speech output from the speaker 18.

[0069] Figure 3 FIG. 1 shows an example of a report by the navigation device 10. As shown on the display 17, the vehicle equipped with the navigation device 10 is scheduled to travel along a route that will turn right at the intersection X after going straight. The intersection X is set as the next guidance point. The control unit 16 predicts the time until reaching the intersection X, and reports that the vehicle will reach the right turn point after the predicted time has passed by voice and / or text display on the display 17. As an example, Figure 3The dialog box of the vehicle contains the content of the voice report. Thus, the user can know in advance that the vehicle will turn right after the predicted time has passed. For example, if there are multiple lanes, the user can move the vehicle to the right lane in advance. Therefore, the user can smoothly turn right at the intersection X.

[0070] It should be noted that the timing of reporting the predicted time to the guidance location to the user can be set according to various conditions. For example, the control unit 16 can be set to report the predicted time to the guidance location to the user when passing the immediately previous guidance location and / or when the distance to the next guidance location reaches a predetermined length. In addition, the control unit 16 can also be set to report the predicted time to the next guidance location or the destination at a predetermined time interval.

[0071] (Processing performed by the control unit)

[0072] Below, use Figure 4 An example of the flow of processing executed by the control unit 16 of the navigation device 10 will be described. Figure 4 An example of an information processing method executed by the control unit 16 is shown. The method disclosed in this specification can be executed by a processor included in the control unit 16 according to a program. Such a program can be stored in a non-transitory computer-readable medium. Examples of non-transitory computer-readable media include hard disks, RAM, ROM, flash memory, CD-ROM, optical storage devices, magnetic storage devices, etc., but are not limited thereto.

[0073] The user is assumed to be able to select whether to provide a report based on the predicted time from the input unit 14 of the navigation device 10. The user can make such a selection or change the selection before or during route guidance. The following processing is based on the assumption that the user has selected guidance based on the predicted time.

[0074] First, the control unit 16 acquires a destination input by a user from the input unit 14 ( S01 ).

[0075] The control unit 16 searches for a route from the current position detected by the positioning unit 13 to the destination, and sets the route ( S02 ).

[0076] The control unit 16 extracts a guide point from the route (S03). The extracted guide point includes a guide point that the vehicle will arrive at next.

[0077] The control unit 16 calculates the distance from the vehicle on which the navigation device 10 is mounted to the guidance point ( S04 ).

[0078] The control unit 16 determines whether the reporting condition for reporting the predicted time to the guidance location to the user is satisfied (S05). For example, the control unit 16 may report the predicted time to the next guidance location when passing through one of the guidance locations. In addition, the control unit 16 may report the predicted time to the next guidance location or the destination as the final guidance location every time a specified time has passed. Furthermore, the control unit 16 may report the predicted time to the next guidance location when the distance to the next guidance location becomes within a specified distance. It should be noted that S04 may be executed after S05 without using the distance to the guidance location for determining the reporting condition.

[0079] If the reporting condition is satisfied in S05 (S05: Yes), the control unit 16 proceeds to the process of S06. If the reporting condition is not satisfied in S05 (S05: No), the control unit 16 returns to the process of S03.

[0080] When the notification condition is satisfied in S05 ( S05 : YES), the control unit 16 calculates the predicted time to the guidance point ( S06 ).

[0081] The control unit 16 estimates the error of the calculated prediction time (S07). The traffic congestion on the route traveled by the vehicle, traffic lights, temporary stops, right turns and left turns on the route, etc. can be considered as factors that cause the error of the prediction time. The control unit 16 can estimate the longest time estimated to be taken from the current position to the guidance point, and the difference between the estimated time and the prediction time is taken as the error. The longest time can be calculated by adding the longest time taken to pass through the congested section and the longest time to wait for the signal, etc.

[0082] The control unit 16 determines whether the error rate of the predicted time is less than or equal to a threshold value (S08). If the error rate is less than or equal to the threshold value (S08: Yes), the control unit 16 proceeds to S10. If the error rate exceeds the threshold value (S08: No), the control unit 16 proceeds to S09.

[0083] When the error rate exceeds a predetermined value (S08: No), the control unit 16 may switch from the notification based on the predicted time to the notification based on the distance to the guidance point (S09). In the following description, it is assumed that the switching to the notification based on the distance (S09) is not performed.

[0084] Alternatively, the control unit 16 may have other determination conditions in place of the determination condition based on the error rate in S08, or in addition to the determination condition based on the error rate in S08. For example, the control unit 16 may determine not to report the predicted time when there is a serious congestion or an accident on the path to the guidance point based on the traffic information received from the server 30. Alternatively, the control unit 16 may determine not to report the predicted time to the next guidance point when the distance to the next guidance point is short.

[0085] Next, the control unit 16 generates a report content to be reported to the user (S10). The report content includes the predicted time to the guidance location. The report content may include information related to the guidance location. For example, the report content may include the name of the guidance location. In addition, if the guidance location is a right turn location or a left turn location, the information may be included. If the right turn or left turn is not made at the guidance location, the report content may include information indicating that the vehicle should go straight along the road to the guidance location.

[0086] The control unit 16 causes the output unit 15 to output the report content (S11). The control unit 16 displays the report content as text on the display 17 and / or converts it into a voice signal and outputs it as voice from the speaker 18 (S11). By reporting the time until the guide location is reached, the user can sense the approach of the guide location. Assuming that the distance until the guide location is reached is reported to the user, even if the distance is the same, the time to reach the guide location will be different depending on the speed. By reporting the time until the guide location, the user can sense the time margin until the guide location.

[0087] As long as the destination has not been reached (S12: No), the control unit 16 returns to S03 to continue the route guidance including the notification of the estimated time to the guidance point. When the destination has been reached (S12: Yes), the control unit 16 ends the process.

[0088] As described above, according to this embodiment, when performing route guidance, the time required to reach the guidance point on the route can be used to convey the guidance point in a manner that is easy to grasp by sense. This makes the guidance of the navigation device 10 easier to understand by sense.

[0089] It should be noted that the present invention is not limited to the above-mentioned embodiments, and various modifications or changes can be made. For example, the functions included in each unit, each step, etc. can be reconfigured in a logically non-contradictory manner, and multiple units or steps can be combined into one, or divided.

[0090] In the above-mentioned embodiment, the error rate of the estimated predicted time based on the error of the predicted time is used as a method for determining the accuracy of the predicted time. However, the method for determining the accuracy of the predicted time is not limited to this.

[0091] For example, it is generally assumed that in an urban area, the predicted time is prone to error due to congestion, etc., while in a suburban area with less traffic, the predicted time is less likely to be wrong. Therefore, the road map may be divided into an urban area and a suburban area, etc., and the accuracy of the predicted time may be determined based on the proportion of the urban area in the route traveled by the vehicle.

[0092] In addition, machine learning may be used to determine the accuracy of the predicted time. That is, a large amount of data with information on the vehicle's route as input and the error between the predicted time and the actual time as output is used as learning data, and a learned model is generated in advance by a computer for machine learning. The control unit 16 can use the learned model to estimate the error of the predicted time of the route to be traveled.

[0093] In the above-described embodiment, the processing of the navigation device 10 is executed by the control unit 16 in the navigation device 10. However, at least a part of the processing of the control unit 16 may be executed by a computer external to the navigation device 10 via the communication network 20. For example, the navigation device 10 may cause an external computer to calculate the predicted time until reaching the guidance location and estimate the error of the predicted time.

Claims

1. A navigation device, mounted on a vehicle, for guiding the vehicle's travel path, wherein: The navigation device comprises: A position information acquisition unit, which acquires the current position of the vehicle; A storage unit for storing map information; an output unit for outputting information to a user; and The control unit extracts a guidance point on the route based on the current position and the map information, estimates a predicted time required to reach the guidance point, and causes the output unit to output the predicted time.

2. The navigation device according to claim 1, wherein: The control unit does not output the predicted time when the distance from the current position to the guidance point is shorter than a predetermined distance.

3. The navigation device according to claim 1, wherein: The control unit evaluates the accuracy of the predicted time and determines whether to output the predicted time based on the accuracy.

4. The navigation device according to claim 3, wherein: The control unit estimates an error rate of the predicted time as the accuracy, and outputs the predicted time when the error rate is equal to or less than a predetermined threshold.

5. The navigation device according to claim 1, further comprising: The Communications Department can obtain traffic information, When acquiring traffic information indicating a congestion condition of the route, the control unit estimates the predicted time based on the traffic information.

Images