JP2010107391A - Route search device, route search method, route search program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To search for a route corresponding to the accuracy of position information. <P>SOLUTION: First, position-related information related to the position of a movable body is acquired by an acquisition part 103. Next, the acquisition part 103 acquires, as position-related information, position measurement information transmitted from a satellite, for example, or output information of a sensor for detecting the moving state of the movable body. Next, position information on a present position of the movable body is calculated by a calculation part 105 based on the position-related information. The accuracy of the position information is determined by a determination part 106. Next, a route corresponding to the accuracy of the position information is searched for by a search part 107. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a route search device, a route search method, a route search program, and a recording medium that output guidance information according to the accuracy of position information of a current location of a mobile object.

  2. Description of the Related Art Conventionally, there has been proposed a route search device that performs a route search using road map data and travel history data stored in a storage medium (see, for example, Patent Document 1 below). This route search device searches for a route using a road that has traveled in the past among roads not included in the normal route search included in the road map data. That is, an appropriate route is searched in consideration of the past travel route of the user of the route search device.

Japanese Patent Laid-Open No. 11-257985

  However, in the technique of Patent Document 1 described above, the route to be searched can be changed according to the past travel history of the user. For example, if the user has traveled in the past, a tunnel or narrow street Or a path that passes through a link such as a branch road that cannot be calculated accurately unless the accuracy of the position information is good. In this case, for example, when the accuracy of the position information of the route search device is relatively poor, there is a problem that the current position of the vehicle is deviated and accurate route guidance cannot be performed.

  In order to solve the above-described problem and achieve the object, the route search device according to the invention of claim 1 is configured to acquire position-related information related to a position of a moving body, and to move based on the position-related information. Characterized in that it comprises: calculating means for calculating position information of the current position of the body; determining means for determining the accuracy of the position information; and route searching means for searching for a route according to the accuracy of the position information. .

  According to a tenth aspect of the present invention, there is provided a route search method for obtaining position-related information related to a position of a moving body, and calculating position information of the current location of the moving body based on the position-related information. The method includes a step, a determination step for determining accuracy of the position information, and a route search step for searching for a route according to the accuracy of the position information.

  A route search program according to an invention of claim 11 causes a computer to execute the route search method according to claim 10.

  A recording medium according to a twelfth aspect of the invention is characterized in that the route search program according to the eleventh aspect is recorded in a computer-readable state.

  Exemplary embodiments of a route search device, a route search method, a route search program, and a recording medium according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment)
(Functional configuration of route search device)
First, a functional configuration of the route search apparatus 100 according to the embodiment of the present invention will be described. FIG. 1 is a block diagram showing a functional configuration of the route search apparatus according to the present embodiment. In FIG. 1, the route search apparatus 100 includes a storage unit 101, an output unit 102, an acquisition unit 103, a setting unit 104, a calculation unit 105, a determination unit 106, and a search unit 107.

  For example, map information is stored in the storage unit 101. The map information includes road network data composed of nodes and links, and image data drawn using features relating to facilities, roads, and other terrain (mountains, rivers, land). The map information may include character information, information such as facility names and addresses, road and facility images, and the like. The output unit 102 includes a display screen that displays map information. The output unit 102 may include a speaker that outputs audio information.

  The acquisition unit 103 acquires position related information related to the position of the moving object. Specifically, the acquisition unit 103 acquires positioning information transmitted from a satellite as position related information. Specifically, the positioning information transmitted from the satellite is, for example, positioning information transmitted from a plurality of GPS (Global Positioning System) satellites.

  Moreover, the acquisition part 103 may acquire the output information of the sensor which detects the movement state of a moving body as position relevant information. Examples of the sensor include a gyro sensor, an acceleration sensor, a vehicle speed pulse, and a reverse line.

  The setting unit 104 sets an attachment angle of the route search device 100. Specifically, the setting unit 104 calculates the pitch direction / yaw direction / roll direction with respect to a predetermined reference based on, for example, output information of a sensor that detects the moving state of the moving body acquired by the acquisition unit 103 or the like. Then, the mounting angle of the route search device 100 is set. In addition, the setting unit 104 may set the route search device 100 to the attachment angle input by the user.

  The calculation unit 105 calculates the position information of the current location of the mobile object based on the position related information acquired by the acquisition unit 103. The calculation unit 105 may calculate the position information of the current position of the moving object using the positioning information and the output information of the sensor, or may use only the positioning information or the output information of the sensor to determine the current position of the moving object. May be calculated.

  Further, the calculation unit 105 may calculate position information indicating the current location of the mobile object based on the position related information acquired by the acquisition unit 103 and the map information stored in the storage unit 101. That is, the map matching process using the map information may be performed on the position information indicating the current location of the moving object calculated based on the position related information. The map matching process is, for example, a road where the current position of the moving object on the map information indicates a point other than a road, but the moving object is likely to be actually located if a predetermined condition is met. This is a process to correct the current location.

  The determination unit 106 determines the accuracy of the position information. The determination unit 106 determines the accuracy of the position information based on, for example, the positioning information acquisition state by the acquisition unit 103. Specifically, the acquisition state of the positioning information includes, for example, the positioning dimension of the GPS satellite, the reception intensity of the radio wave from the GPS satellite, the elevation angle and the number of captured satellites related to the GPS satellite, and the presence / absence of multipath. The determination unit 106 determines the accuracy of the position information using at least one of these positioning information acquisition states. Here, the number of captured satellites is the number of satellites that can receive radio waves by the acquisition unit 103. In order for the calculation unit 105 to calculate the position information, the positioning information received from the four satellites by the acquisition unit 103 is necessary. When the number of captured satellites by the acquisition unit 103 is more than that, the accuracy of the position information calculated by the calculation unit 105 is improved by setting the combination of the four satellites to a combination with less positioning information error. In addition, even when the number of captured satellites is less than 4, the accuracy of the position information is reduced, but the position is calculated by the calculation unit 105 by correcting the error using a timing unit (not shown) that measures the exact time or map information. Information can be calculated.

  Multipath refers to a multiwave transmission path. For example, a radio wave from a GPS satellite is reflected or diffracted by a feature such as a mountain or a building, and the same radio wave is received from a plurality of paths. At this time, there is a time difference between the direct wave that connects the shortest distance straight from the GPS satellite, and the reflected wave or diffracted wave, or the strength of the radio wave decreases, and the accuracy of the positioning information deteriorates. For this reason, the determination part 106 determines with the accuracy of position information being bad, when the multipath has arisen in the positioning information by the acquisition part 103. FIG.

  The determination unit 106 determines the accuracy of the position information based on the output information acquisition state by the acquisition unit 103. Specifically, the output state acquisition state includes, for example, the presence / absence of an output from a gyro sensor, the presence / absence of an output from an acceleration sensor, the presence / absence of a vehicle speed pulse, the presence / absence of a reverse signal, and the learning status of these sensors. The determination unit 106 determines the accuracy of the position information using at least one of these output information acquisition states. That is, for example, the determination unit 106 determines that the accuracy of the position information is higher as the type of output information from the acquisition unit 103 is larger. The determination unit 106 may determine the accuracy of the position information by combining the acquisition state of the positioning information and the acquisition state of the output information.

  Further, the determination unit 106 may determine the accuracy of the position information based on the attachment angle by the setting unit 104. For example, when the attachment angle by the setting unit 104 is equal to or greater than a predetermined value, the determination unit 106 determines that the accuracy of the position information is poor because the output error of the output information from the sensor increases.

  The determination unit 106 may determine the accuracy of the position information based on the attribute of the map information around the current location indicated by the position information. Specific attributes of map information are, for example, inside tunnels and around exits, inside and around multi-story parking lots or underground parking lots, underpasses, buildings that are likely to cause multipath, and mountainous areas. Etc. For example, the determination unit 106 determines that the accuracy of the position information is poor when the vicinity of the current point indicated by the position information has these attributes on the map information.

  The search unit 107 searches for a route according to the accuracy of the position information determined by the determination unit 106. For example, when the accuracy of the position information is poor, the search unit 107 searches for a route so as to avoid a tunnel, a narrow street, and a branch road. Specifically, for example, the search unit 107 changes the cost of links corresponding to tunnels, narrow streets, and branch roads according to the accuracy of the position information, and the cost of these links decreases as the accuracy of the position information decreases. Try to increase. By doing so, it is possible to search for a route that avoids many tunnels, narrow streets, and branch roads as the accuracy of the position information is worse. Note that the route searched by the search unit 107 may be output to the output unit 102.

  Further, when the accuracy of the position information is changed during route guidance, the search unit 107 may re-search for a route according to the accuracy of the changed position information. That is, when the accuracy of the position information determined by the determination unit 106 is changed after the search unit 107 has already searched for a route according to the accuracy of the position information, the search unit 107 increases the accuracy of the changed position information. The corresponding route may be searched again.

(Route search processing procedure of route search device)
Next, a route search processing procedure of the route search device 100 will be described. FIG. 2 is a flowchart showing a route search processing procedure of the route search device. In the flowchart of FIG. 2, first, the acquisition unit 103 acquires position related information related to the position of the moving object (step S201). In step S201, for example, the positioning information transmitted from the satellite and the output information of the sensor that detects the moving state of the moving body are acquired as the position related information.

  Next, the position information of the current location of the moving object is calculated by the calculation unit 105 based on the position related information acquired in step S201 (step S202). In step S202, the position information of the current location of the mobile object may be calculated based on the position related information acquired in step S201 and the map information stored in the storage unit 101.

  Next, the determination unit 106 determines the accuracy of the position information calculated in step S202 (step S203). In step S203, the accuracy of the position information is determined based on the positioning information acquisition state and output information acquisition state acquired in step S201. In step S203, when the position information of the current location of the mobile object is calculated based on the position related information and the map information in step S202, the map information around the current location indicated by the calculated location information is displayed. The accuracy of the position information may be determined based on the attribute.

  Next, the search unit 107 searches for a route according to the accuracy of the position information determined in step S203 (step S204), and the series of processing ends. In step S204, specifically, the search is performed so as to avoid tunnels, narrow streets, and branch roads as the accuracy of the position information determined in step S203 is worse.

  In the flowchart of FIG. 2, after the position related information is acquired in step S <b> 201, the attachment angle of the route search device 100 may be set by the setting unit 104. In this case, in step S203, the accuracy of the position information may be determined based on the attachment angle set by the setting unit 104.

  In the flowchart of FIG. 2, in step S204, a route corresponding to the accuracy of the position information is searched and the series of processes is terminated. However, the present invention is not limited to this. After searching for a route in step S204, the process may return to step S201 and the subsequent processing may be repeated. In this case, for example, it may be determined whether or not the mobile object has arrived at the destination point, and when the mobile object has arrived at the destination point, the series of processes may be terminated.

  As described above, according to the route search device 100 of the present embodiment, the calculation unit 105 calculates the position information of the current location of the moving object based on the position related information acquired by the acquisition unit 103, and the determination unit 106 can determine the accuracy of the position information. Then, the search unit 107 can search for a route according to the accuracy of the position information. Therefore, when the accuracy of the position information is relatively good, a route by a normal route search such as a route with the shortest distance can be searched. Further, when the accuracy of the position information is relatively poor, it is possible to search for a route that avoids a link that is likely to cause a difference between the calculated current location and the actual current location. Therefore, even when the accuracy of the position information is relatively poor, it is possible to suppress the deviation between the current location on the map and the actual current location, and perform accurate route guidance. Thereby, the user can move the guide route without hesitation to the destination point because there is no deviation between the actual position and the position on the map while moving the guide route.

  Further, according to the route search device 100 of the present embodiment, the acquisition unit 103 acquires the positioning information transmitted from the satellite as the position related information, and the determination unit 106 enters the positioning information acquisition state by the acquisition unit 103. Based on this, the accuracy of the position information can be determined. Therefore, the accuracy of the position information can be determined based on the positioning dimension of the GPS satellite, the reception intensity from the satellite, the number of captured satellites, and the presence or absence of multipath. For this reason, it is possible to accurately determine the accuracy of the position information.

  Further, according to the route search device 100 of the present embodiment, the acquisition unit 103 acquires the output information of the sensor that detects the moving state of the moving body as the position related information, and the determination unit 106 outputs the output by the acquisition unit 103. The accuracy of the position information can be determined based on the information acquisition state. Therefore, based on the presence / absence of output information from the gyro sensor, the presence / absence of output information from the acceleration sensor, the presence / absence of output information from the vehicle speed sensor, the presence / absence of output information from the reverse line, and the learning state of each sensor, Accuracy can be determined. Thus, it can be determined that the more types of sensors that have acquired the output information, the better the accuracy of the position information. For this reason, it is possible to accurately determine the accuracy of the position information.

  Further, according to the route search device 100 of the present embodiment, the accuracy of the position information can be determined by the determination unit 106 based on the attachment angle of the route search device 100 set by the setting unit 104. Therefore, when the mounting angle is greater than or equal to a predetermined value, the output error from the sensor becomes large, so it can be determined that the accuracy of the position information is poor. For this reason, it is possible to accurately determine the accuracy of the position information.

  Further, according to route search device 100 of the present embodiment, calculation unit 105 calculates position information indicating the current location of the moving object based on position-related information and map information, and determination unit 106 determines position information. The accuracy of the position information can be determined based on the attribute of the map information around the current location indicated by. Therefore, the map matching process can be performed to correct the error in the position information calculated based on the position related information. In addition, when the current location indicated by the location information is inside a tunnel or exit, inside a multi-story parking lot or underground parking lot, around an exit, under an overpass, in a building town where there is a high possibility of multipath, or in a mountainous area It can be determined that the accuracy of the position information is poor. For this reason, for example, even when output information from a plurality of sensors is acquired and it is determined that the accuracy of the position information is good, the accuracy of the position information is poor in a section where it is difficult to receive radio waves from GPS satellites. Can be determined. Therefore, it is possible to accurately determine the accuracy of the position information.

  Moreover, according to the route search device 100 of the present embodiment, when the position information is not accurate by the search unit 107, a route can be searched to avoid a tunnel, a narrow street, or a branch road. Therefore, if the accuracy of the location information is poor, these links can be increased by increasing the cost of links corresponding to tunnels, narrow streets, or branch roads where there is a high possibility of deviation between the calculated current location and the actual current location. It is possible to search for a route that avoids as much as possible. This prevents the user from knowing where he / she is when the current location on the map is shifted from the actual current location while moving through a tunnel, narrow street, or branch road, for example, according to a guidance route. be able to. For this reason, it is possible to move along the guide route without getting lost to the destination point.

  Moreover, according to the route search device 100 of the present embodiment, when the accuracy of the position information is changed during route guidance by the search unit 107, the route according to the changed accuracy of the position information is re-searched. Can do. Therefore, for example, even when the accuracy of the position information is deteriorated after the route is searched, the route according to the case where the accuracy of the position information is poor can be searched again. As a result, even if the accuracy of the position information changes for some reason during the route guidance, for example, the user can always be guided along the route according to the accuracy of the position information. Can be moved.

  Examples of the present invention will be described below. In the present embodiment, an example in which the route search device of the present invention is implemented by a navigation device mounted on a moving body such as a vehicle (including a four-wheeled vehicle and a two-wheeled vehicle) will be described.

(Hardware configuration of navigation device)
Next, a hardware configuration of the navigation device 300 according to the present embodiment will be described. FIG. 3 is a block diagram of a hardware configuration of the navigation device according to the present embodiment. In FIG. 3, the navigation device 300 includes a CPU 301, a ROM 302, a RAM 303, a magnetic disk drive 304, a magnetic disk 305, an optical disk drive 306, an optical disk 307, an audio I / F (interface) 308, and a microphone 309. A speaker 310, an input device 311, a video I / F 312, a display 313, a communication I / F 314, a GPS unit 315, various sensors 316, and a camera 317. Each component 301 to 317 is connected by a bus 320.

  First, the CPU 301 governs overall control of the navigation device 300. The ROM 302 stores programs such as a boot program, a data update program, a mounting angle setting program, a position information calculation program, a map matching processing program, a position accuracy determination program, and a route search program. The RAM 303 is used as a work area for the CPU 301. That is, the CPU 301 controls the entire navigation device 300 by executing various programs recorded in the ROM 302 while using the RAM 303 as a work area.

  The attachment angle setting program causes the attachment angle of the navigation device 300 to be set. The attachment angle setting program calculates the pitch direction / yaw direction / roll direction with respect to a predetermined reference based on output information from the GPS unit 315 and various sensors 316 described later, and sets the attachment angle of the navigation device 300. Further, the attachment angle setting program may cause the navigation device 300 to be set to the attachment angle input by the user.

  The position information calculation program calculates position information of the current position of the vehicle using output information from a GPS unit 315 described later and output values from various sensors 316. The position information calculation program may calculate position information using output information from the GPS unit 315 and output values from the various sensors 316, output information from the GPS unit 315, or output values from the various sensors 316. The position information may be calculated using only.

  The map matching processing program is based on the position information calculated by the position information calculation program and the map information recorded on the magnetic disk 305 or the optical disk 307, which will be described later, on the road where the vehicle is likely to be actually located. The position of is specified. Thereby, the error of the position information calculated by the position information calculation program is corrected. In addition, the map matching processing program may display a mark representing the current location of the vehicle at a position on the road where the vehicle in the map information is likely to be actually located.

  The position accuracy determination program determines the accuracy of the position information calculated by the position information calculation program or the position information whose error is corrected by the map matching processing program. Although details will be described later, the position accuracy determination program determines the accuracy of the position information based on, for example, the positioning information acquisition state by the GPS unit 315 and the output value acquisition states by the various sensors 316. In addition, when the position accuracy calculation program calculates the position information by the position information calculation program, for example, the calculation based on the output information from the GPS unit 315 and the output values from the various sensors 316 is based on the GPS unit 315. It is determined that the accuracy of the position information is better than the calculation based on only the output information. Further, it is determined that the accuracy of the position information is higher as the types of output values from the various sensors 316 are larger.

  Further, the position accuracy determination program determines that the position accuracy is worse than other attributes when the position on the map indicating the current location of the vehicle specified by the map matching processing program is a predetermined attribute. The predetermined attributes include, for example, the inside of the tunnel and the vicinity of the exit, the interior and the vicinity of the exit of the three-dimensional parking lot or the underground parking lot, the underpass, a building district where a multipath is likely to occur, and a mountainous area.

  The route search program searches for a route according to the accuracy of the position information determined by the position accuracy determination program. Although the details will be described later, the route search program changes the cost of the link according to the tunnel, narrow street, or branch road included in the map information according to the accuracy of the position information. The cost of these links increases as the accuracy of the position information is worse. By doing so, it is possible to search for a route that avoids many tunnels, narrow streets, and branch roads as the accuracy of the position information is worse.

  The magnetic disk drive 304 controls the reading / writing of the data with respect to the magnetic disk 305 according to control of CPU301. The magnetic disk 305 records data written under the control of the magnetic disk drive 304. As the magnetic disk 305, for example, an HD (hard disk) or an FD (flexible disk) can be used.

  The optical disk drive 306 controls reading / writing of data with respect to the optical disk 307 according to the control of the CPU 301. The optical disk 307 is a detachable recording medium from which data is read according to the control of the optical disk drive 306. As the optical disc 307, a writable recording medium can be used. As a removable recording medium, in addition to the optical disk 307, an MO, a memory card, or the like may be used.

  Examples of information recorded on the magnetic disk 305 and the optical disk 307 include map information and function information. The map information includes background data that represents features (features) such as buildings, rivers, and the ground surface, and road shape data that represents the shape of the road, and is composed of multiple data files divided by district. ing.

  The road shape data further includes traffic condition data. The traffic condition data includes, for example, whether or not there is a signal or a pedestrian crossing, whether or not there is a highway doorway or junction, the length (distance) of each link, road width, direction of travel, road type (highway, Such as toll roads and general roads).

  The function information is three-dimensional data representing the shape of the facility on the map, character data representing the description of the facility, and other various data other than the map information. Map information and function information are recorded in blocks divided into districts or functions. Specifically, for example, the map information is recorded in such a state that each map can be divided into blocks so that each map represents a predetermined district on the map displayed on the display screen. Further, for example, the function information is recorded in a state where each function can be divided into a plurality of blocks so as to realize one function.

  The function information is data for realizing functions such as program data for realizing route search, calculation of required time, route guidance, etc. in addition to the above-described three-dimensional data and character data. Each of the map information and the function information is composed of a plurality of data files divided for each district or for each function.

  The audio I / F 308 is connected to a microphone 309 for audio input and a speaker 310 for audio output. The sound received by the microphone 309 is A / D converted in the sound I / F 308. For example, the microphone 309 may be installed near the sun visor of the vehicle, and the number thereof may be one or more. From the speaker 310, a sound obtained by D / A converting a predetermined sound signal in the sound I / F 308 is output. Note that the sound input from the microphone 309 can be recorded on the magnetic disk 305 or the optical disk 307 as sound data.

  Examples of the input device 311 include a remote controller having a plurality of keys for inputting characters, numerical values, various instructions, and the like, a keyboard, and a touch panel. The input device 311 may be realized by any one form of a remote control, a keyboard, and a touch panel, but can also be realized by a plurality of forms.

  The video I / F 312 is connected to the display 313. Specifically, the video I / F 312 is output from, for example, a graphic controller that controls the entire display 313, a buffer memory such as a VRAM (Video RAM) that temporarily records image information that can be displayed immediately, and a graphic controller. And a control IC for controlling the display 313 based on the image data to be processed.

  The display 313 displays icons, cursors, menus, windows, or various data such as characters and images. On the display 313, the above-described map information is drawn two-dimensionally or three-dimensionally. The map information displayed on the display 313 can be displayed with a mark representing the current location of the vehicle on which the navigation device 300 is mounted. The current location of the vehicle is calculated by the CPU 301.

  As the display 313, for example, a CRT, a TFT liquid crystal display, a plasma display, or the like can be used. The display 313 is installed near the dashboard of the vehicle, for example. A plurality of displays 313 may be installed in the vehicle, for example, in the vicinity of the dashboard of the vehicle or in the vicinity of the rear seat of the vehicle.

  The communication I / F 314 is connected to a network via wireless and functions as an interface between the navigation device 300 and the CPU 301. The communication I / F 314 is further connected to a communication network such as the Internet via wireless, and also functions as an interface between the communication network and the CPU 301.

  Communication networks include LANs, WANs, public line networks and mobile phone networks. Specifically, the communication I / F 314 includes, for example, an FM tuner, a VICS (Vehicle Information and Communication System) / beacon receiver, a radio navigation device, and other navigation devices, and traffic and traffic distributed from the VICS center. Get road traffic information such as regulations. VICS is a registered trademark. The communication I / F 314 is configured by an in-vehicle wireless device that performs two-way wireless communication with a wireless device installed on the roadside, for example, when using DSRC (Dedicated Short Range Communication), and traffic information and map information Get various information. A specific example of DSRC is ETC (non-stop automatic fee payment system).

  The GPS unit 315 receives radio waves from GPS satellites and outputs positioning information related to the position of the vehicle. The output information of the GPS unit 315 is used when the position information of the current location of the vehicle is calculated by the CPU 301 together with output values of various sensors 316 described later. The information indicating the current location is information for specifying one point on the map information such as latitude / longitude and altitude. The GPS unit 315 normally receives radio waves from four GPS satellites, but when the number of captured satellites is more than four, the combination of the four GPS satellites is set to the combination with the smallest positioning information error. Further, the GPS unit 315 can output positioning information even when the number of captured satellites is less than four. In this case, when the position information of the current location of the vehicle is calculated by the CPU 301, positioning information in which an error is corrected by using a timing unit (not shown), map information, or the like that measures an accurate time is used.

  The various sensors 316 output information for determining the position and behavior of the vehicle, such as a vehicle speed sensor, an acceleration sensor, and an angular velocity sensor. The output values of the various sensors 316 are used by the CPU 301 to calculate the position information of the current location of the vehicle and to calculate the amount of change in speed and direction. Various sensors 316 may output information for judging whether the vehicle is moving forward or backward from the reverse line. As the types of output values output from the various sensors 316 increase, the accuracy of the position information of the current location of the vehicle calculated by the CPU 301 improves. The navigation device 300 may not include the various sensors 316. In this case, the position information of the current location of the vehicle is calculated using only the output information of the GPS unit 315.

  The camera 317 captures images inside or outside the vehicle. The image may be either a still image or a moving image. For example, the behavior of the passenger inside the vehicle is photographed by the camera 317, and the photographed image is output to a recording medium such as the magnetic disk 305 or the optical disk 307 via the video I / F 312. To do. The camera 317 captures a situation outside the vehicle, and outputs the captured video to a recording medium such as the magnetic disk 305 or the optical disk 307 via the video I / F 312. Further, the camera 317 has an infrared camera function, and the surface temperature distributions of objects existing inside the vehicle can be relatively compared based on video information captured using the infrared camera function. The video output to the recording medium is overwritten and stored.

  The storage unit 101, the output unit 102, the acquisition unit 103, the setting unit 104, the calculation unit 105, the determination unit 106, and the search unit 107 included in the route search device 100 illustrated in FIG. 1 are the ROM 302 in the navigation device 300 illustrated in FIG. The CPU 301 executes a predetermined program using programs and data recorded in the RAM 303, the magnetic disk 305, the optical disk 307, etc., and controls each part in the navigation device 300, thereby realizing its function.

  That is, the navigation device 300 of the embodiment executes the route search program recorded in the ROM 302 as a recording medium in the navigation device 300, thereby providing the functions provided in the route search device 100 shown in FIG. It can be executed by the route search processing procedure shown.

(Contents of navigation device processing)
Next, the contents of the processing of the navigation device will be described. FIG. 4 is a flowchart showing the contents of processing of the navigation device. In the flowchart of FIG. 4, first, it is determined whether or not the positioning information transmitted from the GPS satellite has been acquired (step S401). It detects (step S402) and progresses to step S403.

  If positioning information has not been acquired in step S401 (step S401: No), the process proceeds to step S403 as it is, and it is determined whether or not output values from the various sensors 316 have been acquired (step S403). When an output value is acquired in step S403 (step S403: Yes), an output value acquisition state is detected (step S404). And the attachment angle of the navigation apparatus 300 set by executing the attachment angle setting program is detected (step S405), and the process proceeds to step S406.

  If the output value is not acquired in step S403 (step S403: No), the process proceeds to step S406 as it is, and the position information calculation program is executed to calculate the position information of the current point of the vehicle (step S406). Further, the map matching processing program is executed to perform map matching processing (step S407). Then, the attribute of the map information around the current point indicated by the position information specified in step S407 is detected (step S408).

  Next, the position accuracy determination program is executed to determine the accuracy of the position information calculated in step S406 or the position information after the map matching process is performed in step S407 (step S409). In step S409, information on whether or not positioning information has been acquired in step S401, information on whether or not an output value has been acquired in step S403, and information detected in steps S402, S404, S405, and S408 are used. The accuracy of the position information is determined.

  If it is determined that the accuracy of the position information is poor (step S410: No), the cost of the predetermined link included in the map information is increased (step S411), and the process proceeds to step S412. In step S411, the predetermined link is, for example, a tunnel, a narrow street, or a branch road. If it is determined in step S410 that the accuracy of the position information is good (step S410: Yes), the process directly proceeds to step S412 to determine whether or not the destination point of the vehicle is set (step S412).

  When the destination point is set in step S412 (step S412: Yes), a route to the destination point is searched (step S413). Here, when searching for a route to the destination point in step S413, for example, the route is searched so that the cost of the link is as low as possible. Accordingly, in step S413, a route is searched to avoid the link whose cost has been increased in step S411. Next, it is determined whether or not the vehicle has reached the destination point (step S414). When the vehicle has reached the destination point (step S414: Yes), the series of processes is terminated.

  On the other hand, when the destination point is not set in step S412 (step S412: No), when the destination point has not been reached in step S414 (step S414: No), the process returns to step S401 and the subsequent processing is repeated.

  In the flowchart of FIG. 4, after determining the accuracy of the position information in step S409, it is determined in step S410 whether the accuracy of the position information is good. However, the present invention is not limited to this. Specifically, for example, in step S410, not only whether the accuracy of the position information is good or bad, but also ranking may be performed in three or more stages. In this case, the cost corresponding to the rank may be increased for a predetermined link. By doing in this way, cost can be increased, so that the accuracy of position information is bad. Therefore, a route can be searched so that a tunnel, a narrow street, and a branch road are avoided more so that the accuracy of position information is worse.

  In the flowchart of FIG. 4, after searching for a route in step S413, the process proceeds to step S414 to determine whether or not the destination point has been reached. However, the present invention is not limited to this. Specifically, for example, after the route is searched in step S413, the searched route may be output to the display 313 or the speaker 310.

(About an example of the contents of processing for determining the accuracy of position information)
Next, the contents of the process for determining the accuracy of the position information in step S409 in the flowchart of FIG. 4 will be described with reference to FIG. FIG. 5 is an explanatory diagram showing an example of the content of processing for determining the accuracy of position information. As shown in FIG. 5, for example, “state” 502 is detected for each item of “position related information” 501, and “−” 511 or “+” 512 “evaluation” is detected for each “state” 502. "510" to determine accuracy.

  Specifically, for example, when “position-related information” 501 is an attachment angle, it is determined as “state” 502 whether the attachment angle is a predetermined value or more. Since the output error of the output information from the GPS unit 315 and various sensors 316 increases when the mounting angle is greater than or equal to a predetermined value, “−” 511 is set, and when the mounting angle is less than the predetermined value, “+” 512 is set.

  Further, when the “position related information” 501 is the GPS unit 315, as the “state” 502, whether the positioning dimension is equal to or greater than a predetermined value, whether the reception intensity is equal to or greater than a predetermined value, and whether the number of captured satellites is equal to or greater than a predetermined value Or whether a multipath has occurred. Then, for each “state” 502, “evaluation” 510 of “−” 511 or “+” 512 is determined to determine accuracy.

  Here, whether or not the number of captured satellites is equal to or greater than a predetermined value is determined by determining whether or not the number of satellites that can receive radio waves by the GPS unit 315 is four or more. In general, in order to calculate position information by GPS, positioning information received from four satellites by the GPS unit 315 is required. Therefore, when the number of captured satellites is four or more, “+” 512 is set. Also, even if the number of captured satellites is less than 4, the accuracy of the position information is reduced, but the position information is calculated by correcting the error using a timekeeping unit (not shown) or map information that measures the exact time. be able to. However, if the number of captured satellites is less than 4, the accuracy of the position information deteriorates, so “−” 511 is set. When the number of satellites captured by the GPS unit 315 is greater than 4, the accuracy of the position information is further improved by making the combination of the four satellites a combination with less positioning information error.

  Multipath refers to a multiwave transmission path. For example, a radio wave from a GPS satellite is reflected or diffracted by a feature such as a mountain or a building, and the same radio wave is received from a plurality of paths. At this time, there is a time difference between the direct wave that connects the shortest distance straight from the GPS satellite, and the reflected wave or diffracted wave, or the strength of the radio wave decreases, and the accuracy of the positioning information deteriorates. For this reason, when multipath has occurred in the positioning information received by the GPS unit 315, “−” 511 is set.

  Further, when the “position related information” 501 is the various sensors 316, as the “state” 502, whether the output value from the gyro sensor is acquired, whether the output value from the acceleration sensor is acquired, whether from the vehicle speed sensor Whether or not the output value from the reverse line is acquired, and whether or not the learning state of the sensor is equal to or greater than a predetermined value. Then, for each “state” 502, the “evaluation” 510 of “−” 511 or “+” 512 is determined to determine the accuracy. That is, as the number of types of sensors from which output values are acquired increases, “+” 512 increases in “evaluation” 510, and it is determined that the accuracy of position information is good.

  Further, when “location related information” 501 is an attribute of map information, as “state” 502, whether or not the current location of the vehicle is inside the parking lot or around the exit, whether inside the underground parking lot or around the exit It is determined whether it is inside the tunnel or around the exit, whether it is under an overpass, whether it is a building town where a multipath is highly likely to occur, and whether it is a mountainous area. Then, for each “state” 502, the “evaluation” 510 of “−” 511 or “+” 512 is determined to determine the accuracy.

  Then, for example, the “evaluation” 510 of each “state” 502 for each “position related information” 501 is added / subtracted, and the accuracy of the position information is determined by the total numerical value. The higher the numerical value, the better the accuracy, and the lower the numerical value, the worse the accuracy. Further, the total numerical values may be ranked, and the accuracy of the position information may be divided into a plurality of ranks for determination. In the present embodiment, the accuracy of the position information is determined as “accuracy A” when the accuracy of the position information is determined to be the best, and “accuracy B” is determined as the accuracy of the position information next. A case where it is determined to be the worst is defined as “accuracy C”. In the present embodiment, the accuracy of position information is determined by dividing the rank into three, but the present invention is not limited to this. There may be two ranks or more than three ranks. Note that the “evaluation” 510 of the predetermined “position-related information” 501 or the predetermined “state” 502 may be weighted. That is, different points may be added / subtracted for each “position related information” 501 and for each “state” 502.

(Example of route searched by navigation device)
Next, an example of a route searched by the navigation device 300 in step S413 in the flowchart of FIG. 4 will be described with reference to FIGS. 6 to 8, for example, in FIG. 5, it is determined that the accuracy of the position information is good in the case of “accuracy A” and the accuracy of the position information is bad in the case of “accuracy B” or “accuracy C”. Judgment is made. FIG. 6 is an explanatory diagram showing a route that avoids a tunnel. In FIG. 6, the case where the link from the current location 601 to the destination location 602 of the vehicle includes a link 603 corresponding to the tunnel will be described. As shown in FIG. 6, when the accuracy of the position information is good, the navigation apparatus 300 searches for a route 604 that passes through the tunnel and a route 605 that avoids the tunnel. On the other hand, when the accuracy of the position information is poor, the navigation apparatus 300 increases the cost of the link 603 corresponding to the tunnel, so that only the route 605 that avoids the tunnel is searched without searching for the route 604 passing through the tunnel. Explore. Therefore, when the position information is not accurate, it is possible to search for a route so as to avoid the link 603 corresponding to the tunnel, where accurate position information is not calculated unless the position information is accurate.

  FIG. 7 is an explanatory diagram showing a route that avoids a narrow street. In FIG. 7, a case where a link 703 corresponding to a narrow street is included in the link from the current point 701 to the destination point 702 of the vehicle will be described. As shown in FIG. 7, when the accuracy of the position information is good, the navigation device 300 searches for a route 704 that passes through the narrow street, which is the shortest route from the current point 701 to the destination point 702. On the other hand, when the accuracy of the position information is low, the navigation device 300 avoids the narrow street in preference to the shortest route from the current location 701 to the destination location 702 by increasing the cost of the link 703 corresponding to the narrow street. A route 705 is searched for. Therefore, when the accuracy of the location information is good, the shortest route is searched. When the accuracy of the location information is bad, the accurate location information is not calculated unless the location information is accurate. The route can be searched to avoid it.

  FIG. 8 is an explanatory diagram showing a route that avoids a branch path. In FIG. 8, the case where the link from the current location 801 to the destination location 802 of the vehicle includes a link 803 corresponding to the branch road will be described. As shown in FIG. 8, when the accuracy of the position information is good, the navigation device 300 searches for a route 804 that passes through the branch path, which is the shortest route from the current point 801 to the destination point 802. On the other hand, when the accuracy of the position information is poor, the navigation device 300 avoids the branch path in preference to the shortest path from the current point 801 to the destination point 802 by increasing the cost of the link 803 corresponding to the branch path. A route 805 is searched for. Therefore, when the accuracy of the position information is good, the shortest route is searched, and when the accuracy of the position information is bad, the accurate position information cannot be calculated unless the position information is accurate. The route can be searched to avoid it.

  6 to 8, the case where the accuracy of the position information is determined in two stages, that is, the case where the accuracy of the position information is good and the case where the position information is bad is described, but the present invention is not limited to this. Specifically, for example, the accuracy of the position information may be ranked, and the accuracy of the position information may be determined in three or more stages. If the rank is higher than the predetermined rank, the shortest path is searched. If the rank is lower than the predetermined rank, a path that avoids the tunnel, narrow street, and branch path is searched. Also, for example, depending on the accuracy rank of location information, the amount of increase in the cost of links corresponding to tunnels, narrow streets, and branch roads is changed. You may make it search for the path | route which avoids more.

  As described above, according to the navigation device 300 of the embodiment, the state of the mounting angle of the navigation device 300, the acquisition state of the positioning information of the GPS unit 315, the acquisition state of the output values of the various sensors 316, the map information around the current location The accuracy of the position information can be ranked by the numerical value obtained by summing the evaluations of the attributes and the like. Then, it is possible to search for a route corresponding to the accuracy rank of the position information.

  Further, according to the navigation device 300 of the embodiment, if it is determined that the accuracy of the position information is relatively poor, for example, if the accuracy of the position information is poor, such as a tunnel, a narrow street, or a branch road, the current location on the map It is possible to preferentially search for a route that avoids these links by increasing the cost of the links that are likely to cause a deviation from the actual current location. In addition, when it is determined that the accuracy of the position information is relatively good, it is possible to search for a normally searched route such as the shortest distance route.

  As described above, according to the route search device, route search method, route search program, and recording medium of the present invention, it is possible to search for a route according to the accuracy of the position information of the current location of the mobile object.

  Note that the route search method described in this embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer, a workstation, or a mobile terminal device (mobile phone). This program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. The program may be a transmission medium that can be distributed via a network such as the Internet.

It is a block diagram which shows the functional structure of the route search apparatus concerning this Embodiment. It is a flowchart which shows the route search processing procedure of a route search apparatus. It is a block diagram which shows the hardware constitutions of the navigation apparatus concerning a present Example. It is a flowchart which shows the content of the process of a navigation apparatus. It is explanatory drawing shown about an example of the content of the process which determines the precision of position information. It is explanatory drawing shown about the path | route which avoids a tunnel. It is explanatory drawing shown about the path | route which avoids a narrow street. It is explanatory drawing shown about the path | route which avoids a branched path.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Route search apparatus 101 Memory | storage part 102 Output part 103 Acquisition part 104 Setting part 105 Calculation part 106 Judgment part 107 Search part

Claims (12)

Acquisition means for acquiring position-related information relating to the position of the moving object;
Based on the position related information, calculating means for calculating position information of the current location of the mobile body;
Determination means for determining the accuracy of the position information;
Search means for searching for a route according to the accuracy of the position information;
A route search apparatus comprising: The acquisition means acquires positioning information transmitted from a satellite as the position related information,
The route search device according to claim 1, wherein the determination unit determines the accuracy of the position information based on an acquisition state of the positioning information by the acquisition unit. The acquisition means acquires output information of a sensor that detects a moving state of the moving body as the position related information,
The route search device according to claim 1, wherein the determination unit determines the accuracy of the position information based on an acquisition state of the output information by the acquisition unit. Further comprising setting means for setting the mounting angle of the route search device;
The route search device according to claim 1, wherein the determination unit determines the accuracy of the position information based on the attachment angle. The calculation means calculates position information indicating a current location of the mobile body based on the position related information and map information,
The route according to any one of claims 1 to 4, wherein the determination unit determines the accuracy of the position information based on an attribute of the map information around the current point indicated by the position information. Search device.   6. The route search device according to claim 1, wherein the search unit searches for a route so as to avoid a tunnel when the accuracy of the position information is poor.   The route search device according to any one of claims 1 to 6, wherein the search means searches for a route so as to avoid a narrow street when the accuracy of the position information is poor.   The route search device according to any one of claims 1 to 7, wherein the search means searches for a route so as to avoid a branch path when the accuracy of the position information is poor.   9. The search unit according to claim 1, wherein, when the accuracy of the position information is changed during route guidance, the search unit re-searches for a route according to the accuracy of the changed position information. The route search device described in 1. An acquisition step of acquiring position-related information regarding the position of the moving object;
Based on the position related information, a calculation step of calculating position information of the current location of the mobile body,
A determination step of determining the accuracy of the position information;
A search step for searching for a route according to the accuracy of the position information;
A route search method comprising:   A route search program causing a computer to execute the route search method according to claim 10.   A computer-readable recording medium on which the route search program according to claim 11 is recorded.

Images