JP2009229241A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device capable of stopping guiding at an adequate location on an expressway when a user uses the expressway in a guide route to his home. <P>SOLUTION: When there is an expressway in the guide route to the home, a number of junctions through which a vehicle runs from a present position to a position for going into a general road in the expressway to the home passing through the general road, is acquired. The number of junctions is compared with a preset number of junctions for stopping the guiding. When the number of junctions is smaller than the preset one, the guiding of the guide route is stopped. In the event of stopping the guiding, it is possible to select one from a process in which the guiding is stopped while leaving the guide route and guiding can be started by performing rerouting when the vehicle is out of the guide route, and a process in which the guiding is stopped while deleting data of the guide route and starting of guiding by rerouting is prevented when the vehicle is intentionally out of the guide route. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a navigation device for guiding a vehicle to a destination, and in particular, during traveling on a guidance route to a home using a highway, automatically stops annoying guidance when the vehicle can easily travel to the home without guidance. The present invention relates to a navigation device that can be used.

  In a general navigation device mounted on a vehicle or the like, a map / information data storage medium such as a DVD or a hard disk on which map data for drawing a map and facility information data for searching a facility are recorded, and this map / A data capture device that captures data from an information data storage medium, a monitor that displays a map, etc., and a self-contained navigation device that uses a GPS receiver, a mileage sensor, a gyro, etc. A vehicle position detection device that detects the vehicle position, fetches map data including the current position of the vehicle from the map / information data storage medium, and draws a map image around the vehicle position on the monitor screen based on the map data. The vehicle position mark is displayed superimposed on the monitor screen, and the map image is scrolled or displayed as the vehicle moves. Moving the fixed vehicle position mark an image on a screen, so that seen whether the vehicle is traveling where the current at a glance.

  Map data stored in a map / information data storage medium such as a DVD or hard disk is divided into longitude and latitude widths of appropriate sizes according to various scale levels. It is stored as a coordinate set of represented nodes. A road is composed of a combination of two or more nodes, and map data displays a road layer consisting of a road list, a node table, an intersection configuration node list, etc., and roads, buildings, facilities, parks, rivers, etc. on the map screen. Map data such as a background layer, and information data for displaying characters, map symbols, etc., such as administrative division names such as municipalities, road names, intersection names, and facility names.

  In addition, this navigation device is provided with a route guidance function for allowing the user to easily travel on the road toward a desired destination or waypoint without making a mistake. According to this route guidance function, a destination is set by various means, and an appropriate route is calculated and presented in consideration of various conditions among routes connecting these points from the departure point to the destination. It has become. Also, the route selected by the user is stored as a guide route, and while driving, the guide route is drawn on the map image with a different color from other routes and displayed on the screen. When approaching an intersection where the course of course should be changed within a certain distance, the intersection is enlarged and displayed on the screen by drawing an arrow indicating the direction in which the course should be changed, or a right or left turn is guided by voice. In this way, the user can be guided to the destination.

  In the above navigation device, even when driving on a highway, the guidance route along the highway is displayed on a normal map screen for guidance, and the highway is displayed abstractly by straightening, etc. JCT), interchanges, service areas, etc., as well as distance display, service area facility information, etc. are displayed as appropriate, and junction lane information, etc. at junctions are guided by voice and screen.

In the guidance during traveling on the guide route, Japanese Patent Application Laid-Open Publication No. 2003-259259 discloses that the technology that does not perform intersection guidance or the like on a road where the number of times the vehicle has traveled is a predetermined number or more. In addition, Patent Document 2 discloses a technique for preventing guidance at a branch point that travels within a predetermined number of days from the previous travel date, and a technique for not performing route guidance on a road having a large number of travels. Japanese Patent Application Laid-Open No. H10-26092 and Japanese Patent Application Laid-Open No. H10-260260 disclose a technique in which guidance is not performed when approaching within a predetermined distance from a destination.
Japanese Patent Laid-Open No. 11-201770 Japanese Patent Laid-Open No. 2002-236028 JP 2006-313085 A JP 2007-78573 A

  As described above, in order to safely guide the driver to the destination, the current navigation apparatus displays various detailed guidance on the monitor screen and provides guidance by voice output. Such guidance is extremely effective in places where guidance is unfamiliar to the driver, but for example, guidance is often unnecessary on roads near the home. Therefore, for example, when returning to a home from a remote location, when a guidance route is set with the home as the destination, traveling along the guidance route and accompanying various guidance, Even if it is in the range of a known road, the guidance continues to be annoying, and the display of various types of guidance information on the monitor screen is often annoying.

  As a countermeasure, there has been proposed a technique for avoiding guidance on roads and destinations that frequently pass, as disclosed in the various patent documents. However, these technologies, for example, when the destination is at home, although it is considered that various guidance such as intersection guidance on general roads around the home is not performed, high-speed on the guidance route to the home No consideration is given to the use of roads and toll roads, such as roads dedicated to automobiles (hereinafter abbreviated as “highways”).

  That is, when using the expressway while traveling on a guide route from a remote place to the home, in most cases, if the vehicle travels along the expressway, it can reach the interchange that goes down to the general road to the home. In addition, most of the nearest interchanges that enter and leave the expressway around the home are well known, and guidance from the interchange to the home is often not required.

  In addition, when there is no junction terminal (JCT) [hereinafter abbreviated as “junction”] where a plurality of highways intersect when driving on a highway, even if there are a large number of interchanges, the highway is simply passed along the highway. If you travel a little, you can reach the nearest interchange, so there is often no need to provide guidance on such roads. Furthermore, even if such junctions exist, the nearest junctions around the home are often well known, and even when such junctions exist on the road, it is better to stop the guidance. is there.

  Therefore, when driving on the guidance route to return to home using the expressway, it is possible to drive to the home without fail even if the guidance is stopped at an appropriate place, but on the general road from the nearest interchange. Of course, guidance is always provided on the highway leading to the nearest interchange. In such highways leading to the nearest interchange, guidance is often unnecessary at least when driving on the highway near the nearest junction, and the voice guidance output here is annoying, and the monitor screen displays The display is often annoying.

  Therefore, the main object of the present invention is to provide a navigation device that can stop the guidance at an appropriate place on the highway when the highway is used on the guide route toward the home.

  In order to solve the above-mentioned problem, the navigation device according to the present invention has a travel junction number capturing unit that captures the number of junctions that travel before reaching the general road on an expressway that reaches the general road leading to the home on the guidance route. A guide stop condition that sets the number of junctions to stop guidance, and a guide stop condition that the number of junctions captured by the junction number capture unit is less than the number of junctions set by the guide stop junction number setting unit. Guidance route for stopping guidance of the guidance route when it is determined that the guidance stop condition is satisfied by the highway traveling guidance stop determination unit and the highway traveling guidance stop determination unit that determines whether or not it is satisfied A guidance stop processing unit is provided.

  Another navigation device according to the present invention is characterized in that, in the navigation device, the guidance route guidance stop processing unit stops only guidance route guidance while leaving guidance route data.

  Another navigation apparatus according to the present invention is characterized in that, in the navigation apparatus, the guidance route guidance stop processing unit stops guidance route guidance by deleting the guidance route data.

  In another navigation device according to the present invention, in the navigation device, the guidance stop junction number setting unit stops guiding the guidance route from the start of traveling on the expressway by not setting the junction number. Features.

  Another navigation device according to the present invention provides guidance of a guidance route when the number of times of traveling on a general road in the navigation device is a predetermined number or more, or when the distance to the home is a predetermined value or less. A general road travel guidance stop processing unit for stopping is provided.

  Since the present invention is configured as described above, when using the highway on the guidance route to the home, it is possible to stop the guidance at an appropriate place on the highway, and thereby on the highway leading to the nearest interchange. By guiding the guidance route even on the highway part well known to the driver, it is possible to prevent the annoying or annoying guidance from being automatically performed.

  The present invention aims to be able to stop the guidance at an appropriate place on the highway when using the highway on the guidance route to the home. A traveling junction number capturing unit that captures the number of junctions that travel before getting off the general road, a guidance stop junction number setting unit that sets the number of junctions to stop guidance, and the number of junctions captured by the junction number capturing unit, The guidance stop determination unit during highway driving for determining whether or not the guide stop condition of less than the number of junctions set by the guidance stop junction number setting unit is satisfied, and the guidance stop at the highway driving guidance stop determination unit Guide route plan to stop guiding route guidance when it is determined that the conditions are met It was achieved by providing the stop processing unit.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram of a navigation apparatus according to an embodiment of the present invention, and mainly shows the function of guidance route guidance stop processing which is the subject of the present invention. In the navigation apparatus in FIG. 1, as in the conventional navigation apparatus, a ROM that records software for comprehensively performing various predetermined functions in the system control unit 10, a CPU and a RAM for processing the software, and the like And each functional unit connected thereto is controlled. In the illustrated navigation apparatus, a vehicle position detection unit 13 is connected to the system control unit 10 and position data of the GPS receiver 11 is input. Further, if necessary, a travel distance / orientation detection unit using a vehicle speed sensor or an angle sensor. By inputting the movement data of the vehicle from 12, the current position of the vehicle is accurately detected.

  In the instruction signal input unit 15, an instruction signal for the remote controller 13 or the like by the user in the navigation device is input. Further, a signal of the voice recognition unit 14 that inputs a user instruction signal by processing for recognizing the user's voice as necessary is also input to the instruction signal input unit 15. The data fetching unit 17 fetches various information such as necessary map data and facility information from a map / information data recording medium 16 such as a CD-ROM, DVD-ROM, or hard disk, and the data recording medium is a hard disk. In the case where data can be easily written as described above, data taken from outside or data processed by other functional units can be read and used later.

  In the guidance route calculation unit 18, the current location of the vehicle detected by the vehicle position detection unit 13 is fetched, and the phone number is further input by scrolling the map by operating the cursor displayed on the screen or by inputting an address. The destination set by various methods such as the above is taken in, and the optimum guide route is calculated and presented under various conditions such as the shortest required time, the shortest distance, and the general road priority. This guidance route calculation unit monitors whether or not the currently traveling road is along the guidance route, and calculates again the guidance route from the travel point to the destination when it deviates from the guidance route by a predetermined amount or more.

  The guidance route guide unit 19 provides guidance so that the vehicle can safely reach the destination according to the guidance route calculated by the guidance route calculation unit 18 and selected by the user as described later. At that time, a map is displayed on the monitor 21 from the image output unit 20, and the guidance route, the right / left turn intersection enlarged display, and various information are displayed. Various guidances are output from the audio output unit 22 through the speaker 23.

  The guidance route guidance stop processing unit 31 performs a process of stopping guidance when traveling to the home along the guidance route when the vehicle is traveling on a road known to the driver. The example which enabled it to implement in various aspects is shown. Among them, the expressway travel guidance stop processing unit 32 performs a process of stopping guidance on the expressway under a predetermined condition, particularly when traveling on the expressway in the guidance route to the home. The illustrated guide route guidance stop processing unit 31 further includes an example of a general road travel guidance stop processing unit 33 for performing a guide stop process during travel on a general road on the guide route to the home.

  The expressway travel guidance stop processing unit 32 includes an expressway travel detection unit 34 for detecting that the expressway travels to a general road leading to the home and that the expressway travels on the expressway. The guidance stop junction (JCT) number setting unit 35 sets the number of junctions that exist between the time when the vehicle is traveling on the highway and the time when the vehicle stops on the guidance route until the interchange exiting the highway. For example, you can set 1, 2, 3, ..., etc., set zero if necessary, stop guidance when there is no junction before getting off the highway, and even a specific It is possible to set such as setting to always stop guidance when entering a highway by setting a value. This setting can be set at the start of use of the navigation device or at the start of guided route travel.

  In the planned junction number capturing unit 36, when traveling on a highway on the currently traveling guidance route, if the highway is a highway that goes down to a general road leading to home, the highway is entered. In addition, the number of junctions from the current driving point to the time of getting off the expressway is taken in while traveling on the expressway. This data can be easily imported from the map data.

  In the expressway traveling guidance stop discriminating unit 37, the number of junctions set by the guidance stop junction number setting unit 35 as described above is compared with the number of junctions captured by the planned traveling junction number capturing unit 36, and the traveling schedule is planned. It is determined whether or not the junction number has reached the junction number set by the guidance stop junction number setting unit 35. As a result of the determination, when it is determined that the number of junctions captured by the planned number of traveling junctions capturing unit 36 has reached the number of junctions set by the guidance stop junction number setting unit, the guidance stop function selected by the guidance stop function selection processing unit 46 The guidance route guidance stop processing unit 31 performs guidance stop processing.

  In the embodiment shown in FIG. 1, in addition to the guidance stop processing when there is an expressway on the guidance route as described above, the guidance stop function as described above is also used when traveling on a general road. An example is shown in which guidance stop processing can be performed. That is, the guidance route guidance stop processing unit 31 shown in FIG. 1 is also provided with a general road travel guidance stop processing unit 33. In the illustrated example, the road travel number detection guidance stop processing unit 38 and the distance detection guidance stop processing unit to the home are shown. 39 is shown.

  In the road travel number detection guidance stop processing unit 38, when a general road that is currently being traveled has become a well-known road by traveling several times before, such a road is used as a guide route. The guidance stop travel frequency setting unit 40 stops the guidance when the vehicle travels on the road as the reference data for the guidance stop. The number of times to do is preset.

  The running road travel count capturing unit 41 captures the number of times the general road that is currently traveled has been traveled before, and the data is stored in the memory provided in the navigation device. Every time it is memorized regularly, the data is used. In the travel number detection guidance stop determination unit 42, the reference travel number set by the guide stop travel number setting unit 40 and the previous travel road that has been captured by the traveling road travel number capture unit 41. The number of travels is compared to determine whether the number is greater than the reference number of travels.

  As a result of the determination, when it is determined that the number of times of traveling on the currently traveling road is greater than the reference number, the guidance route guidance stop process is performed according to the function selected by the guidance stop function selection processing unit 46. Here, when it is determined that the number of times the road that is currently being driven is greater than the reference number of times, it is often around the home, and therefore when traveling to the home along the guidance route from a remote location, It is possible to stop guidance route guidance around the home.

  In the distance detection guidance stop processing unit 39 to the home, when the distance to the home falls within a predetermined value, it is determined that the driver is driving on a well-known road, and the guidance is stopped. The stop distance setting unit 43 presets the distance from the home as the reference. The home-to-home distance capturing unit 44 captures the current traveling point and the distance to the home, and the current position detected by the current position detection unit 13 and the home position set as the destination. Calculate and capture the distance. The distance detection guidance stop determination unit 45 to the home compares the reference distance set by the guidance stop distance setting unit 43 with the distance to the home at the current vehicle position captured by the distance capture unit 44. It is determined whether or not the distance is within the reference distance. As a result of the determination, when it is determined that the distance is within the reference distance, the guidance route guidance stop process is performed according to the function selected by the guidance stop function selection processing unit 46 as in the previous period.

  The guidance route guidance stop processing unit 31 shown in FIG. 1 is provided with a guidance stop function selection processing unit 46. In the illustrated example, when the guidance route guidance is stopped, the guidance route data used so far is used. Guidance route holding guidance stop processing unit 47 that performs processing to stop only guidance while being held, and guidance route erasure guidance stop that performs processing that erases the guidance route itself and thereby inevitably stops guidance. A processing unit 48 is provided so that any one can be selected and used.

  When the function of the guidance route holding guidance stop processing unit 47 is selected and used, the guidance route data is retained as it is, so that the navigation device can be used when the vehicle deviates from the previously used guidance route even after the guidance is stopped. Reroute processing is performed by the guide route resetting function, and a new guidance route to the home is set. At that time, appropriate processing such as continuing guidance to the home without performing the guidance stop processing is performed. You can also. In addition, since the guidance route deletion guidance stop processing unit 48 erases the guidance route when the guidance is stopped, it is conscious even when the vehicle is outside the guidance route when it is in the vicinity of the home or the road range is known to the driver. Since it may take another path, it is used to prevent the reroute processing as described above.

  The guidance stop process in the navigation device of the present invention composed of the functional blocks shown in FIG. 1 can be operated by the operation flow shown in FIG. 2, for example. That is, in the navigation apparatus guidance stop process shown in FIG. 2, as a premise, traveling to the home along the guidance route is performed (step S1). In the traveling state, it is determined whether or not the currently set guidance route travels on a highway (step S2). Here, when it is determined that the vehicle is traveling on the highway, the processing of steps S3 to S8 is performed thereafter.

  That is, when it is determined in step S2 that the vehicle is going to travel on the highway, the number of junctions (JCT) from the entrance to the expressway to the general road leading to the home until the exit is obtained (step S3). This processing is performed when the highway travel detection unit 34 in the highway travel guidance stop processing unit 32 of the guidance route guidance stop processing unit 31 in FIG. 1 detects that the vehicle travels on the highway on the guide route. This can be done by obtaining the number of junctions from entering the expressway to getting off for the expressway that gets down to the general road that leads to the home, in particular, in the guidance route by the number capturing unit 36. In this process, when traveling on a plurality of highways that are not connected to each other on the currently set guidance route, the highway that goes down to the general reason leading to the home is selected.

  Next, it is determined whether or not an expressway that goes down to a general road leading to the home is entered (step S4). Thereafter, it is determined whether or not the acquired number of junctions is greater than the set number N (step S5). This operation is performed by comparing the number of junctions captured by the planned traveling junction number capturing unit 36 and the number of junctions set by the guidance stop junction number setting unit 35 in the guidance stop determination unit 37 during traveling on the expressway in FIG. Determined by If it is determined that the number of junctions is not greater than the set number of junctions, that is, the number of guidance stops is within the range of the number of guidance stops, the process proceeds to step S9 to perform guidance stop processing described later. In this way, by performing the determination immediately when entering the highway that leads to the general road leading to the home while traveling on the guidance route, guidance on the guidance route can be stopped immediately when the condition is satisfied.

  When it is determined that the number of junctions acquired in step S5 is greater than the set number N, it is determined whether or not the junction has been passed (step S6). Sometimes, the number of junctions to get off the highway is updated (step S7). Next, it is determined whether or not the updated number of junctions is greater than the set number N (step S8). If the number is still greater than the set number, the process returns to step S6, waits for the next junction to pass, and thereafter repeats the same operation. .

  When it is determined that the updated number of junctions is greater than the set number N by passing through the junction several times in step S8, guidance stop processing is started, and the guidance route is deleted when guidance route guidance is stopped around the home. It is determined whether or not it is set (step S9). When it is determined that the setting is to be deleted, the guidance is stopped by deleting the guide route (step S14), and this process is ended (step S14). S23). If it is determined that such a setting has not been made, the guidance is stopped in a state where the guidance route is held in the illustrated example (step S10). The determination is based on whether the guidance stop function selection processing unit 46 in FIG. 1 selects the processing function of the guidance route holding guidance stop processing unit 47 or the processing function of the guidance route deletion guidance stop processing unit 48. Selected.

  Thereafter, it is determined whether or not the guide route has been removed (step S11). When the guide route is removed, the home guide route is reset (step S12), and thereafter, the operation returns to step S1 and the above operation is repeated. Note that when such a guidance route is reset, it is possible to set so that guidance is always continued until the user returns to the home.

  In the determination of whether or not the guidance route has deviated in step S11, when it is determined that the guidance route is not deviated, it is determined whether or not it has arrived at the home (step S13), and when it has been determined that it has not yet arrived at the home. Returning to step S11 again, the above operation is repeated. If it is determined in step S13 that the user has arrived at the home, this process is terminated (step S23).

  In the example of FIG. 2, the operation when traveling along the highway when traveling along the guidance route to the home is mainly shown, but the guidance stop processing at the time of traveling on a general road using the guidance stop function at that time Can also be done. That is, in the example shown in FIG. 2, when it is determined that the vehicle does not travel on the highway in the determination as to whether or not to travel on the highway in step S2, it is determined whether or not to use the guidance stop function around the home, When it is determined that the function is not used, the process proceeds to step S23 and this process is terminated. When it is determined that this function is to be used, in the example shown in the figure, it is determined whether or not to use the guidance stop function based on the distance to the home (step S16). In this determination, the general road travel guidance stop processing unit 33 in FIG. 1 sets whether to perform the processing in the road travel number detection guidance stop processing unit 38 or to perform the processing in the distance detection guidance stop processing unit 39 to the home. This can be determined by detection.

  If it is determined in step S16 that the guidance stop function based on the distance to the home is not used, the guidance stop function based on the number of road travels by the road travel number detection guidance stop processing unit 38 in FIG. 1 is used (step S17). The number of times of using the inside road is taken in (step S18). Thereafter, it is determined whether or not the number of uses is equal to or greater than a predetermined number (step S19). When it is determined in step S19 that the number of times of use is equal to or greater than the predetermined number, the process proceeds to step S9, and guidance route guidance stop processing is performed in the same manner as described above.

  On the other hand, if it is determined in step S16 that the guidance stop function based on the distance to the home is to be used, processing for using the guidance stop function based on the distance to the home is performed (step S20), and the distance to the home is captured (step S21). ). Thereafter, it is determined whether or not the distance to the home is within the set range (step S22). If it is determined that the distance to the home is not yet within the set range, the process returns to step S21 and the above operation is repeated. When it is determined in step S22 that the set range has been reached, the process proceeds to step S9 to perform the same guidance stop process as described above.

  As a result of performing the processing as described above, when driving on a highway on a guidance route to home, for example, an operation as shown in FIG. 3 can be performed. That is, in the example shown in FIG. 3, when the vehicle C travels on the guidance route indicated by the bold line in the figure, the vehicle C travels on the highway A2 that travels on the highway A1 and the general road B1 and then descends to the general road B2 leading to the home H. In this case, an example is shown in which the interchange IC1 enters the highway A2, passes through junctions J1 to J4, and then exits to the general road B2 at the interchange IC7.

  In this example, as shown in the table of the figure, when the setting of the highway usage guidance stop position is set to 0 junction number, the guidance is stopped after passing through junction J4 and set to 1 junction number. When the vehicle is on the road, the guidance is stopped when the junction J3, which is the junction two steps before the junction leaving the expressway, passes. Similarly, when the number of junctions is set to 2, the guidance is stopped when the junction J2 is passed, and when the number of junctions is set to 3, the guidance is stopped after the junction J1 is passed.

  In the example shown in FIG. 3, by setting the number of junctions as “E” in particular, it is possible to always stop the guidance when entering the expressway, and when the function is selected, when the interchange IC1 is entered The guide can also be stopped. Such a setting can be used when, for example, only the Tomei Expressway is used, even if there are many junctions, when entering the expressway, guidance is not required afterwards.

It is a functional block diagram of the Example of this invention. It is an operation | movement flowchart of the Example. It is a figure which shows the mode of the guidance stop performed in the Example.

Explanation of symbols

31 Guidance route guidance stop processing unit 32 Expressway travel guidance stop processing unit 33 General road travel guidance stop processing unit 34 Expressway travel detection unit 35 Guide stop junction number setting unit 35 Travel planned junction number capturing unit 37 Guide during highway travel Stop determination section 38 Road travel number detection guidance stop processing section 39 Distance detection guidance stop processing section 40 to home Guide stop travel count setting section 41 Traveling road travel count capture section 42 Travel count detection guidance stop determination section 43 Guide stop distance setting Unit 44 Distance to home capture unit 45 Distance detection guidance stop determination unit 46 Guide stop function selection processing unit 47 Guide route holding guidance stop processing unit 48 Guide route erasure guidance stop processing unit

Claims (5)

About the expressway that goes down to the general road leading to the home on the guide route, a traveling junction number capturing unit that captures the number of junctions that travel before getting down to the general road,
A guidance stop junction number setting section for setting the number of junctions for stopping guidance;
A highway traveling guidance stop determining unit that determines whether the number of junctions captured by the junction number capturing unit satisfies a guide stop condition less than the number of junctions set by the guidance stop junction number setting unit;
A navigation apparatus comprising: a guidance route guidance stop processing unit that stops guidance of a guidance route when the guidance stop judgment unit during highway traveling determines that the guidance stop condition is satisfied.   2. The navigation apparatus according to claim 1, wherein the guidance route guidance stop processing unit stops only guidance route guidance while leaving guidance route data.   The navigation device according to claim 1, wherein the guidance route guidance stop processing unit stops guidance route guidance by deleting guidance route data.   The navigation apparatus according to claim 1, wherein the guidance stop junction number setting unit stops guidance of a guidance route from the start of traveling on the expressway by not setting the number of junctions.   A general road travel guidance stop processing unit is provided that stops guidance of a guidance route when the number of travels on a road being traveled is a predetermined number or more when traveling on a general road, or when a distance to a home is a predetermined value or less. The navigation device according to claim 1.

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