JP2013152188A - Azimuth recognition device, control method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an azimuth recognition device having a geomagnetic sensor, in which an azimuth of travel direction can be recognized suitably irrespective of a place.SOLUTION: An azimuth recognition device includes display means, a geomagnetic sensor, storage means, position information generation means, and control means. The storage means stores map data. The position information generation means includes, for instance, a GPS receiver, and generates current position information. The control means causes the display means to display a current position on a map on the basis of map data, output of the geomagnetic sensor, and the position information. Here, in the vicinity of a rail track the control means recognizes an azimuth of travel direction without using output of the geomagnetic sensor.

Description

  The present invention relates to an orientation recognition technique using a geomagnetic sensor.

  2. Description of the Related Art Conventionally, a technique for detecting a traveling direction of a vehicle or a pedestrian using a geomagnetic sensor is known. For example, Patent Document 1 describes a navigation device that detects a walking direction of a pedestrian using a geomagnetic sensor.

JP 2011-169739 A

  In recent years, a portable terminal device such as a high-function mobile phone called a “smart phone” is installed in a moving body such as a vehicle and used. An application similar to a navigation device has been proposed for a smartphone, and the smartphone can be installed in a vehicle and used as a navigation device. Some portable terminal devices of this type have a built-in geomagnetic sensor, and the direction of travel can be recognized based on the output of the geomagnetic sensor. However, the geomagnetic sensor has a problem that the detection accuracy is reduced near a line where a disturbance magnetic field is generated. On the other hand, the above-described portable terminal device has a built-in GPS receiver, and can recognize the direction of travel based on the output of the GPS receiver. However, the GPS receiver has a problem that the accuracy of recognizing the heading in the traveling direction is lowered during low-speed traveling.

  The present invention has been made in order to solve the above-described problems, and in an azimuth recognition device having a geomagnetic sensor, an azimuth recognition device capable of preferably recognizing the azimuth in the traveling direction regardless of the place. The main purpose is to provide.

  The invention according to claim 1 is an azimuth recognition device including a display unit and a geomagnetic sensor, a storage unit that stores map data, and a position information generation unit that generates position information of the azimuth recognition device. Control means for displaying the current position on the map on the map based on the map data, the output of the geomagnetic sensor, and the position information, the control means in the vicinity of the track, It is characterized by recognizing the direction of travel without using the output of the geomagnetic sensor.

  The invention according to claim 9 is a control method executed by an azimuth recognition device comprising display means and a geomagnetic sensor, wherein a storage step for storing map data and position information of the azimuth recognition device are generated. A position information generating step, a control step of displaying the current position on the map on the display unit based on the map data, the output of the geomagnetic sensor, and the position information, the control step comprising: In the vicinity, the direction of travel is recognized without using the output of the geomagnetic sensor.

  The invention according to claim 10 is a program executed by an azimuth recognition device comprising display means and a geomagnetic sensor, wherein the storage means stores map data, and the position for generating position information of the azimuth recognition device. Based on the information generating means, the map data, the output of the geomagnetic sensor, and the position information, the azimuth recognition device is made to function as a control means for displaying the current position on the map on the display means, and the control means Is characterized by recognizing the direction of travel in the vicinity of the track without using the output of the geomagnetic sensor.

1 shows a schematic configuration of a navigation device. It is a figure which shows the transition of the positional relationship of a vehicle and a level crossing at the time of a level crossing approach. It is a flowchart which shows the process sequence which concerns on 1st Example. It is a figure which shows the transition of the positional relationship of a vehicle and a level crossing at the time of a level crossing approach. It is a flowchart which shows the process sequence which concerns on 2nd Example.

  According to a preferred embodiment of the present invention, an azimuth recognition device comprising display means and a geomagnetic sensor, storage means for storing map data, and position information generation for generating position information of the azimuth recognition device. Means for displaying the current position on the map on the map based on the map data, the output of the geomagnetic sensor, and the position information, the control means in the vicinity of the track The direction of travel is recognized without using the output of the geomagnetic sensor.

  The azimuth recognition apparatus includes a display unit, a geomagnetic sensor, a storage unit, a position information generation unit, and a control unit. The storage means stores map data. In this case, the storage means may store map data in advance, or may appropriately store the map data acquired by the communication means. The position information generation means includes a GPS receiver, for example, and generates position information of the current position. The control means displays the current position on the map on the display means based on the map data, the output of the geomagnetic sensor, and the position information. At this time, the control means recognizes the direction of travel in the vicinity of the track without using the output of the geomagnetic sensor.

  In general, the geomagnetic sensor can suitably detect the direction even when the vehicle is traveling at a low speed. On the other hand, the geomagnetic sensor may be affected by a disturbance magnetic field in the vicinity of the track such as when passing a railroad crossing, and may not be able to detect an accurate direction. Considering the above, the direction recognition device can accurately display the current position on the map regardless of the location by recognizing the direction of the traveling direction without using the output of the geomagnetic sensor in the vicinity of the track. .

  In one aspect of the azimuth recognition device, the control means recognizes the azimuth in the vicinity of the line based on the azimuth information output by the geomagnetic sensor immediately before the line becomes near the line. In this aspect, the azimuth recognition device uses the output of the geomagnetic sensor when it is not affected by a disturbance magnetic field when it is in the vicinity of the line, so that it can properly recognize the azimuth in the traveling direction even near the line. Can do.

  In another aspect of the azimuth recognition device, the control unit calculates a change vector of the position indicated by the position information generated by the position information generation unit near the track, and determines the direction based on the change vector. recognize. By doing in this way, even if it is a case where the right-left turn is performed in the vicinity of a track, the direction recognition device can recognize the direction of advancing direction suitably.

  In another aspect of the azimuth recognition device, the position information generating means includes a GPS receiver, and the control means is in the vicinity of a track, and when the traveling speed is a predetermined value or more, the GPS receiver The direction is recognized based on the generated direction information. The above-mentioned “predetermined value” is a threshold value for determining whether or not the accuracy of the direction information generated by the GPS receiver is within an allowable range, and is determined experimentally, for example. In general, the direction information that can be acquired by GPS has a problem that the accuracy is low when moving at low speed. Therefore, in this aspect, the azimuth recognition device recognizes the azimuth in the traveling direction based on the change vector of the position information generated by the GPS receiver at low speed, and based on the azimuth information generated by the GPS receiver when not at low speed. By recognizing the direction of the traveling direction, the direction of the traveling direction can be appropriately recognized.

  In another aspect of the azimuth recognition device, the control unit may change a position indicated by the position information generated by the position information generation unit when there is a right / left turn point in the vicinity of the track on a running road. The vector is calculated, the direction is recognized based on the change vector, and when there is no right or left turn point in the vicinity of the track on the road that is running, the geomagnetic sensor outputs just before the track is in the vicinity. Based on the direction information, the direction is recognized. By doing in this way, even if it is a case where the right-left turn is performed in the vicinity of a track, the direction recognition device can recognize the direction of advancing direction suitably.

  In another aspect of the azimuth recognizing device, the vicinity of the track is an area where the accuracy of the geomagnetic sensor decreases due to a disturbance magnetic field generated from the track. The area described above may be an area that is determined in advance based on measurement or the like and stored in the storage unit, or may be determined as an area within a predetermined distance from the track. By doing in this way, the azimuth | direction recognition apparatus can prevent suitably using a geomagnetic sensor in the area where a disturbance magnetic field produces.

  In another aspect of the azimuth recognition device, a portable terminal. In general, when a current position display or route guidance is performed on a portable terminal such as a cellular phone, the terminal is not fixed, and thus a geomagnetic sensor is often used instead of a gyro sensor as a direction detecting means. Therefore, as in this aspect, even a portable terminal can display the current position using the geomagnetic sensor to the maximum based on the present invention.

  In another aspect of the azimuth recognizing device, when the current position transitions from the vicinity of the track to a position that is not near the track, the control means performs the correction of the geomagnetic sensor and then outputs the geomagnetic sensor. Based on the above, the direction is recognized. By doing so, the azimuth recognition device can recognize the azimuth by suitably using the geomagnetic sensor in which an error has occurred due to the disturbance magnetic field after correction.

  According to another preferred embodiment of the present invention, there is provided a control method executed by an azimuth recognition device comprising display means and a geomagnetic sensor, the storage step storing map data, and the position of the azimuth recognition device A position information generating step for generating information, a control step for displaying the current position on the map on the display unit based on the map data, the output of the geomagnetic sensor, and the position information, and the control The process recognizes the direction of travel in the vicinity of the track without using the output of the geomagnetic sensor. By using this control method, the azimuth recognition device can appropriately recognize the azimuth in the traveling direction while making maximum use of the geomagnetic sensor.

  According to still another embodiment of the present invention, there is provided a program executed by an azimuth recognition device comprising display means and a geomagnetic sensor, the storage means storing map data, and the position information of the azimuth recognition device. Based on the position information generating means to generate, the map data, the output of the geomagnetic sensor, and the position information, the azimuth recognition device functions as a control means for displaying the current position on the map on the display means, The control means recognizes the direction of travel in the vicinity of the track without using the output of the geomagnetic sensor. By using this program, the azimuth recognition device can appropriately recognize the azimuth in the traveling direction while making maximum use of the geomagnetic sensor. Preferably, the program is stored in a storage medium.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Schematic configuration of navigation device]
FIG. 1 shows a schematic configuration of a navigation device 1 common to the embodiments. The navigation device 1 may be a portable terminal or a stationary navigation device. Here, it is assumed that the navigation device 1 performs map display and route guidance including the current position of the vehicle when the vehicle is traveling. As shown in FIG. 1, the navigation device 1 includes a geomagnetic sensor 10, a GPS receiver 18, a system controller 20, a data storage unit 36, a communication device 38, a display unit 40, an audio output unit 50, and an input device 60.

  The geomagnetic sensor 10 has two or three axes orthogonal to each other as detection axes, and outputs a signal corresponding to the deviation angle of the magnetic pole direction (magnetic north direction) with respect to the direction of each axis. That is, the geomagnetic sensor 10 detects the inclination with respect to the magnetic pole direction and outputs a signal corresponding to the inclination.

  A GPS (Global Positioning System) receiver 18 receives radio waves 19 carrying downlink data including positioning data from a plurality of GPS satellites. The positioning data includes latitude and longitude information, azimuth information, and the like, and is used for detecting the absolute position (current position) of the vehicle 2 and detecting the azimuth in the traveling direction.

  The system controller 20 includes an interface 21, a CPU (Central Processing Unit) 22, a ROM (Read Only Memory) 23, and a RAM (Random Access Memory) 24, and controls the entire navigation apparatus 1.

  The interface 21 performs an interface operation between the geomagnetic sensor 10 and the GPS receiver 18 and inputs azimuth information and position information to the system controller 20. The CPU 22 controls the entire system controller 20 by executing a program stored in advance in the ROM 23 or the like. The ROM 23 includes a nonvolatile memory (not shown) in which a control program for controlling the system controller 20 is stored. The RAM 24 stores various data such as route data preset by the user via the input device 60 so as to be readable, and provides a working area to the CPU 22.

  The system controller 20, the data storage unit 36, the communication device 38, the display unit 40, the audio output unit 50, and the input device 60 are connected to each other via the bus line 30.

  The data storage unit 36 is a unit that stores various data used for navigation processing such as map data. The communication device 38 acquires information necessary for map display and route guidance. The data storage unit 36 may store map data in advance. The map data such as the vicinity of the current position is acquired from the server by the communication device 38, and the map data acquired by the communication device 38 is appropriately stored. Also good.

  The display unit 40 displays various display data on a display device such as a display under the control of the system controller 20. Specifically, the system controller 20 reads map data from the data storage unit 36. The display unit 40 displays the map data read from the data storage unit 36 by the system controller 20 on the display screen. In this case, as will be described later, the system controller 20 causes the display unit 40 to display the current position of the vehicle on the map based on the position information acquired from the GPS receiver 18 and the direction information acquired from the geomagnetic sensor 10.

  The display unit 40 includes a graphic controller 41 that controls the entire display unit 40 based on control data sent from the CPU 22 via the bus line 30 and a memory such as a VRAM (Video RAM), and can display image information that can be displayed immediately. A buffer memory 42 that temporarily stores, a display control unit 43 that controls display of a display 44 such as a liquid crystal display or a CRT (Cathode Ray Tube) based on image data output from the graphic controller 41, and a display 44 are provided. . The display 44 functions as an image display unit, and includes, for example, a liquid crystal display device having a diagonal of about 5 to 10 inches.

  The audio output unit 50 is a D / A converter 51 that performs D / A (Digital to Analog) conversion of audio digital data sent from the RAM 24, the data storage unit 36, and the like via the bus line 30 under the control of the system controller 20. And an amplifier (AMP) 52 that amplifies the audio analog signal output from the D / A converter 51, and a speaker 53 that converts the amplified audio analog signal into audio and outputs the audio into the vehicle. .

  The input device 60 includes keys, switches, buttons, a remote controller, a voice input device, and the like for inputting various commands and data. When the display 44 is a touch panel system, the touch panel provided on the display screen of the display 44 also functions as the input device 60.

  Note that the CPU 22 and the like in FIG. 1 correspond to storage means and control means in the present invention.

[Direction recognition method]
Next, a vehicle orientation recognition method using the geomagnetic sensor 10 will be specifically described. In the following, “vehicle orientation” refers to the direction of travel of the vehicle unless otherwise specified.

  Schematically, the system controller 20 recognizes the orientation of the vehicle based on the geomagnetic sensor 10 when the vehicle is not located near the track, and applies the geomagnetic sensor 10 when the vehicle is located near the track. Regardless of the direction of the vehicle. As a result, the system controller 20 accurately recognizes the direction of the vehicle and accurately displays the current position of the vehicle on the map even when the geomagnetic sensor 10 is affected by disturbance.

  This specific embodiment will be described in a first example and a second example.

<First embodiment>
In the first embodiment, the system controller 20 detects the geomagnetic sensor 10 when the distance between the vehicle and the track (also referred to as “inter-track distance Ltag”) transitions below a predetermined distance (also referred to as “distance Lth1”). Is stored, and the direction of the vehicle is recognized based on the stored direction information until the distance Ltag between the tracks becomes greater than the distance Lth1. Here, the distance Lth1 is set, for example, to a value close to the inter-line distance Ltag that causes an error in the geomagnetic sensor 10 due to a disturbance magnetic field generated from the line. Specifically, the distance Lth1 is within a value range of the inter-line distance Ltag where no error occurs in the geomagnetic sensor 10 and is close to a value range of the inter-line distance Ltag where the error occurs in the geomagnetic sensor 10, based on experiments or the like. Predetermined.

  Here, the process of the first embodiment will be described in detail with reference to FIG. FIG. 2 is a diagram showing a transition of the positional relationship between the vehicle and the level crossing when the level crossing is approaching. In FIG. 2, a railroad crossing 610 is provided on the road through which the track 61 passes, and the current position of the vehicle transits from the position “P1” to the position “P4” on the road. A broken line 70 and a broken line 71 indicate positions separated from the line by a distance Lth1.

  First, when the current position of the vehicle is the position P1, the vehicle is separated from the track 61 by a distance Lth1. Therefore, in this case, the system controller 20 determines that there is no error in the geomagnetic sensor 10 and recognizes the direction of the vehicle based on the detection signal of the geomagnetic sensor 10.

  Next, when the current position of the vehicle is the position P2, the vehicle is separated from the track 61 by a distance Lth1. In this case, since the distance between the vehicle and the track 61 is within the distance Lth1, the system controller 20 uses the azimuth information acquired from the geomagnetic sensor 10 as a memory (simply referred to as “memory”) such as the ROM 23 or the data storage unit 36. .)

  When the current position of the vehicle is the position P3, the vehicle is located within the distance Lth1 from the track 61. In this case, the system controller 20 determines that the accuracy of the geomagnetic sensor 10 is low due to the influence of the disturbance, and recognizes the current vehicle orientation based on the orientation information held in the memory without using the output of the geomagnetic sensor 10. As a result, the system controller 20 can correctly recognize the direction of the vehicle even when there is an error in the output of the geomagnetic sensor 10 due to the disturbance magnetic field when passing through the railroad crossing.

  When the current position of the vehicle is the position P4, the vehicle is separated from the track 61 by a distance Lth1. Therefore, in this case, the system controller 20 determines that the geomagnetic sensor 10 is not likely to be affected by the disturbance magnetic field, corrects the geomagnetic sensor 10 by a well-known method, and then based on the output of the geomagnetic sensor 10, Recognize the direction. At this time, the system controller 20 may correct the output of the geomagnetic sensor 10 based on, for example, the orientation information stored in the memory, and the output of the geomagnetic sensor 10 based on the detection value of the GPS receiver 18 or other sensors. May be corrected. Thereby, the system controller 20 can recognize the azimuth | direction of a vehicle accurately based on the detected value of the geomagnetic sensor 10 in the place which is not influenced by the disturbance magnetic field by a track | line.

  In addition, when the vehicle makes a right or left turn while traveling on a place where the distance Ltag between the tracks is equal to or less than the distance Lth1, the system controller 20 determines the road data in the map data based on the current position detected based on the GPS receiver 18, for example. (So-called map matching) may be performed, and the direction along the road data may be recognized as the direction of the vehicle.

(Processing flow)
FIG. 3 is an example of a flowchart showing a processing procedure according to the first embodiment. The system controller 20 repeatedly executes the processing of the flowchart shown in FIG. 3 according to a predetermined cycle.

  First, the system controller 20 determines whether or not the line distance Ltag is equal to or less than the distance Lth1 (step S101). In this case, for example, the system controller 20 determines whether or not the inter-track distance Ltag is less than or equal to the distance Lth1 based on the current position recognized by the GPS receiver 18 and the position information of the track in the map data.

  If the distance Ltag between the lines is equal to or less than the distance Lth1 (step S101; Yes), the system controller 20 determines whether or not the azimuth information acquired from the geomagnetic sensor 10 has been stored in the memory (step S102). If the azimuth information detected by the geomagnetic sensor 10 is not already stored in the memory (step S102; No), the system controller 20 stores the azimuth information acquired from the geomagnetic sensor 10 (step S103). In this case, since the line distance Ltag is immediately after the distance Lth1, the azimuth information acquired from the geomagnetic sensor 10 does not yet have an error.

  And after execution of step S103 or when the direction detected by the geomagnetic sensor 10 has been stored in the memory (step S102; Yes), the system controller 20 recognizes the direction of the vehicle based on the stored direction information. (Step S104). Therefore, in this case, the system controller 20 displays the current position of the vehicle or provides route guidance based on the direction information stored in the memory, regardless of the output of the geomagnetic sensor 10. As described above, when the system controller 20 is close to the line to such an extent that an error of the geomagnetic sensor 10 is generated by the disturbance magnetic field, the direction information immediately before approaching the line, that is, when there is no influence of the disturbance magnetic field. The azimuth information acquired from the geomagnetic sensor 10 is used. By doing in this way, the system controller 20 can recognize the azimuth | direction of a vehicle appropriately irrespective of the presence or absence of the approach of a track | line.

  On the other hand, when the distance Ltag between the lines is not less than or equal to the distance Lth1 (step S101; No), the system controller 20 determines whether correction of the geomagnetic sensor 10 is necessary (step S105). Specifically, the system controller 20 determines whether or not it has approached the line until just before, in other words, whether or not it is immediately after the distance Ltag between the lines has changed from the distance Lth1 or less to a value greater than the distance Lth1. If correction of the geomagnetic sensor 10 is necessary (step S105; Yes), the system controller 20 determines that the geomagnetic sensor 10 has been affected by the disturbance magnetic field and corrects the geomagnetic sensor 10 (step S106). For example, the system controller 20 corrects the output of the geomagnetic sensor 10 based on the azimuth information acquired from the GPS receiver 18.

  Next, after the execution of step S106 or when the correction of the geomagnetic sensor 10 is not necessary (step S105; No), the system controller 20 recognizes the direction of the vehicle based on the output of the geomagnetic sensor 10 (step S107). . Therefore, in this case, the system controller 20 displays the current position of the vehicle or provides route guidance based on the direction information acquired from the geomagnetic sensor 10.

<Second embodiment>
In the second embodiment, the system controller 20 determines that the change vector (“change vector Vc”) of the current position detected by the GPS receiver 18 when the line distance Ltag is equal to or less than a predetermined distance (also referred to as “distance Lth2”). Is also referred to as ")." Thereby, the system controller 20 preferably recognizes the direction of the vehicle even when the vehicle makes a right or left turn when approaching the track.

  Here, the above-mentioned distance Lth2 is a threshold value of the inter-line distance Ltag for determining whether or not an error occurs in the geomagnetic sensor 10 due to the disturbance magnetic field of the line, and is determined based on, for example, experiments. In the second embodiment, the system controller 20 calculates the change vector Vc based on two or more pieces of position information acquired most recently from the GPS receiver 18. Here, when the system controller 20 calculates the change vector Vc based on three or more pieces of continuous position information, for example, a moving average of vectors calculated based on two pieces of continuous position information is determined as the change vector Vc. Also good.

  Next, the processing of the second embodiment will be specifically described with reference to FIG. FIG. 4 is a diagram showing a transition of the positional relationship between the vehicle and the level crossing when approaching the level crossing. In FIG. 4, a railroad crossing 610A is provided on the road through which the track 61A passes. Further, the positions “P1A” to “P8A” indicate the positions where the GPS receiver 18 has generated the position information in time series. A broken line 70A and a broken line 71A indicate positions separated from the line 61A by a distance Lth2.

  First, when the vehicle is at the position P1A, the system controller 20 determines that there is no error in the output of the geomagnetic sensor 10 because the distance Ltag between the lines is greater than the distance Lth2, and the vehicle based on the output of the geomagnetic sensor 10 Recognize the direction. In this case, preferably, the system controller 20 may store the position information of the current position necessary for calculating the change vector Vc in the memory. Here, every time the GPS receiver 18 generates position information, the system controller 20 may store the position information in a memory, and when it is determined that the line distance Ltag is equal to or less than the distance Lth2 within a predetermined time. Only the position information may be stored in the memory. In the latter case, for example, the system controller 20 determines whether or not the distance Ltag between the tracks is equal to or less than the distance Lth2 within a predetermined time based on the direction of the vehicle and the vehicle speed detected by the GPS receiver 18 and other sensors. .

  Next, when the vehicle is at the position P2A, the system controller 20 determines that the geomagnetic sensor 10 is affected by the disturbance magnetic field because the line distance Ltag is equal to or less than the distance Lth2. Therefore, in this case, the system controller 20 calculates the change vector Vc based on two or more pieces of position information generated by the GPS receiver 18, and recognizes the direction indicated by the change vector Vc as the vehicle direction.

  When the position information necessary for calculating the change vector Vc is not stored in the memory, the system controller 20 reduces the distance Ltag between the lines to the distance Lth2 or less until the necessary number of position information is stored in the memory. You may recognize the azimuth | direction of a vehicle based on the azimuth | direction information which the geomagnetic sensor 10 detected just before becoming.

  When the vehicle is at the positions P3A and P4A, the system controller 20 similarly calculates the change vector Vc based on the position information generated by the GPS receiver 18, and recognizes the direction indicated by the change vector Vc as the direction of the vehicle. .

  Next, the vehicle turns left at the intersection from position P4A to position P6A. Even in this case, the system controller 20 calculates the change vector Vc based on the position information generated by the GPS receiver 18, and recognizes the direction indicated by the change vector Vc as the direction of the vehicle. Thereby, the system controller 20 can recognize the azimuth | direction of a vehicle appropriately, even if it is a case where the azimuth | direction of a vehicle changes with a left turn.

  Furthermore, the vehicle turns right at the intersection from position P6A to position P8A. Even in this case, the system controller 20 calculates the change vector Vc based on the current position calculated by the GPS receiver 18, and recognizes the direction indicated by the change vector Vc as the azimuth of the vehicle. Thereby, the system controller 20 can recognize the azimuth | direction of a vehicle appropriately even if it is a case where the azimuth | direction of a vehicle changes with a right turn.

  Next, when the vehicle is at the position P8A, the system controller 20 determines that the geomagnetic sensor 10 is not likely to be affected by the disturbance magnetic field, corrects the geomagnetic sensor 10, and then outputs it to the output of the geomagnetic sensor 10. Based on the direction of the vehicle. As described above, the system controller 20 recognizes the direction of the vehicle based on the geomagnetic sensor 10 in a place not affected by the disturbance magnetic field, compared with the case where the direction of the vehicle is recognized based on the GPS receiver 18. In particular, the direction of the vehicle can be accurately recognized even when traveling at a low speed.

(Processing flow)
FIG. 5 is an example of a flowchart showing a processing procedure according to the second embodiment. The system controller 20 repeatedly executes the process of the flowchart shown in FIG. 5 according to a predetermined cycle.

  First, the system controller 20 determines whether or not the line distance Ltag is equal to or less than the distance Lth2 (step S201). In this case, for example, the system controller 20 determines whether or not the distance Ltag between the tracks is equal to or less than the distance Lth2 based on the current position recognized by the GPS receiver 18 and the position information of the tracks in the map data.

  When the distance Ltag between the tracks is equal to or less than the distance Lth2 (step S201; Yes), the system controller 20 recognizes the vehicle direction based on the position information change vector Vc generated by the GPS receiver 18 (step S202). . Therefore, in this case, the system controller 20 displays the current position of the vehicle based on the direction indicated by the change vector Vc of the position information generated by the GPS receiver 18 regardless of the output of the geomagnetic sensor 10, and provides route guidance. Or do. As a result, the system controller 20 can preferably correctly recognize the direction of the vehicle even in a place where a disturbance magnetic field is generated.

  On the other hand, when the distance Ltag between the lines is not less than or equal to the distance Lth2 (step S201; No), the system controller 20 determines whether correction of the geomagnetic sensor 10 is necessary (step S203). In other words, the system controller 20 determines whether or not the line has approached the line until just before, that is, whether or not the geomagnetic sensor 10 has been affected by the disturbance magnetic field until just before. If correction of the geomagnetic sensor is necessary (step S203; Yes), the system controller 20 determines that the geomagnetic sensor 10 has been affected by the disturbance magnetic field until immediately before, and corrects the geomagnetic sensor 10 (step S204). For example, the system controller 20 corrects the output of the geomagnetic sensor 10 based on the change vector Vc calculated immediately before.

Next, after execution of step S204 or when correction of the geomagnetic sensor 10 is not necessary (step S203; No), the system controller 20 recognizes the direction of the vehicle based on the output of the geomagnetic sensor 10 (step S205). . Therefore, in this case, the system controller 20 displays the current position of the vehicle or provides route guidance based on the output of the geomagnetic sensor 10. As a result, the system controller 20 can recognize the vehicle direction more accurately even when traveling at a low speed, compared with the case where the vehicle direction is recognized based on the output of the GPS receiver 18 [Modification].
Hereinafter, modifications of the first and second embodiments will be described. These modifications may be applied in combination to the above-described embodiments.

(Modification 1)
The system controller 20 may execute a combination of the control based on the first embodiment and the control based on the second embodiment. For example, when the system controller 20 travels in an area where the distance Ltag between the tracks is equal to or less than a predetermined distance, the change vector Vc is calculated based on the second embodiment when a road traveling in the area has a right / left turn point. Use to recognize the direction of the vehicle. On the other hand, the system controller 20 determines the first embodiment when the road that is running in the area where the distance Ltag between the tracks is equal to or less than the predetermined distance does not have a right or left turn point, that is, when the running road is a substantially straight road. The direction of the vehicle is recognized using the direction information stored in the memory based on the above. Also according to this aspect, the system controller 20 can preferably correctly recognize the direction of the vehicle.

(Modification 2)
The navigation device 1 is not limited to being mounted on a vehicle, and may be attached to another moving body or may be held by a pedestrian. Even in these cases, the navigation device 1 preferably performs processing based on the first embodiment and / or the second embodiment, thereby appropriately recognizing the direction of the traveling direction and mapping the current position and the like. Can be displayed accurately on top.

(Modification 3)
In the example shown in FIG. 2 of the first embodiment, the system controller 20 determines whether or not the distance Ltag between the lines on the horizontal plane is equal to or less than the distance Lth1, but in addition to this, three-dimensional including the vertical direction It may be determined whether the straight line distance between the track and the vehicle in the space is within the distance Lth1. For example, the system controller 20 uses the output of the geomagnetic sensor 10 when the vehicle travels on an elevated road passing over the track, and the three-dimensional linear distance between the track and the vehicle is equal to or less than the distance Lth1. Without recognizing the direction of the vehicle.

  Similarly, in the example shown in FIG. 4 of the second embodiment, the system controller 20 determines whether the line distance Ltag on the horizontal plane is equal to or less than the distance Lth2, but in addition to this, the vertical direction is included. Alternatively, it may be determined whether the straight line distance between the track and the vehicle in the three-dimensional space is within the distance Lth2.

(Modification 4)
In the second embodiment, when the distance Ltag between lines is equal to or less than the distance Lth2, the system controller 20 recognizes the direction of the vehicle based on the absolute position change vector Vc output from the GPS receiver 18. Instead, the system controller 20 may recognize the azimuth of the vehicle based on the azimuth information output from the GPS receiver 18 (also referred to as “GPS azimuth information”). In this case, the system controller 20 takes into account that the accuracy of the GPS direction information decreases when the vehicle is low in speed, and uses the GPS direction information when the vehicle speed is equal to or higher than the predetermined speed, and when the vehicle speed is lower than the predetermined speed. The change vector Vc may be used. Even in these cases, the system controller 20 can preferably correctly recognize the direction of the vehicle at the place where the disturbance magnetic field is generated.

(Modification 5)
The navigation apparatus 1 determines whether the distance between the lines Ltag is equal to or less than the distance Lth1 or the distance Lth2, thereby determining whether the distance between the lines is close to the line, that is, whether it is affected by a disturbance magnetic field. Instead, the navigation apparatus 1 may store in advance an area that is affected by a disturbance magnetic field caused by a track in advance as map data. For example, the area may be memorized in advance from the distance to the track, etc., or the road intersects with a track such as a road adjacent to the track, a road running along the track, a railroad crossing, an elevated road, and an underpass road A road or the like may be stored as an area affected by a disturbance magnetic field. In this case, the system controller 20 determines whether or not the vehicle is traveling on the road in the area based on the current position recognized by the GPS receiver 18 and the map data. It is possible to recognize the direction of travel without depending on the output of the sensor 10.

  The present invention can be suitably applied to an in-vehicle navigation device, a PND (Portable / Personal Navigation Device), a mobile phone such as a smartphone, and other devices that display a current position together with a map.

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 10 Geomagnetic sensor 12 GPS receiver 20 System controller 22 CPU
36 Data storage unit 38 Communication device 40 Display unit 44 Display

Claims (10)

An orientation recognition device comprising display means and a geomagnetic sensor,
Storage means for storing map data;
Position information generating means for generating position information of the azimuth recognition device;
Based on the map data, the output of the geomagnetic sensor, and the position information, control means for displaying the current position on the map on the display means,
With
The azimuth recognition apparatus characterized in that the control means recognizes the azimuth in the traveling direction without using the output of the geomagnetic sensor near the track.   The azimuth recognition apparatus according to claim 1, wherein the control unit recognizes the azimuth in the vicinity of a line based on the azimuth information output by the geomagnetic sensor immediately before the line is in the vicinity of the line.   2. The control unit according to claim 1, wherein the control unit calculates a change vector of a position indicated by the position information generated by the position information generation unit in the vicinity of the track, and recognizes the direction based on the change vector. The orientation recognition device described. The position information generating means includes a GPS receiver,
The azimuth according to claim 3, wherein the control means recognizes the azimuth based on azimuth information generated by the GPS receiver when the traveling speed is a predetermined value or more near the track. Recognition device. The control means includes
When there is a right or left turn point in the vicinity of the track on a running road, a position change vector indicated by the position information generated by the position information generation unit is calculated, and the direction is recognized based on the change vector. ,
The driving direction is characterized by recognizing the heading based on heading information output by the geomagnetic sensor immediately before being near the railroad track when there is no right or left turn point in the vicinity of the railroad track. The azimuth | direction recognition apparatus of 1.   The azimuth recognition apparatus according to any one of claims 1 to 5, wherein the vicinity of the track is an area where the accuracy of the geomagnetic sensor decreases due to a disturbance magnetic field generated from the track.   The azimuth recognition apparatus according to any one of claims 1 to 6, wherein the azimuth recognition apparatus is a portable terminal.   The control means recognizes the orientation based on the output of the geomagnetic sensor after correcting the geomagnetic sensor when the current position transitions from the vicinity of the track to a position that is not near the track. The azimuth | direction recognition apparatus as described in any one of Claim 1 thru | or 7. A control method executed by an azimuth recognition device comprising a display means and a geomagnetic sensor,
A storage process for storing map data;
A position information generation step of generating position information of the azimuth recognition device;
Based on the map data, the output of the geomagnetic sensor, and the position information, a control step of displaying the current position on the map on the display means,
With
The control method is characterized in that the direction of the traveling direction is recognized in the vicinity of the track without using the output of the geomagnetic sensor. A program executed by an azimuth recognition device comprising a display means and a geomagnetic sensor,
Storage means for storing map data;
Position information generating means for generating position information of the azimuth recognition device;
Based on the map data, the output of the geomagnetic sensor, and the position information, the azimuth recognition device functions as a control means for displaying the current position on the map on the display means,
The program characterized in that the control means recognizes the direction of travel in the vicinity of the track without using the output of the geomagnetic sensor.

Images