JP2011232169A - Navigation device, and travel track recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately reflect the movement of a vehicle to a travel track even at a complex-shaped intersection while reducing the data amount in a navigation device which records the travel track of the vehicle.SOLUTION: The navigation device detects absolute estimated positions P1-P26 of the vehicle which does not depend on map data at every predetermined time. And, the navigation device records the track of detected absolute estimated positions other than the absolute estimated positions P9-P11, P15-P17 and P24-P26 which are detected while the vehicle is traveling straight on a road. In addition, the navigation device records the track of absolute estimated positions in the following cases which is regarded as a satisfied recording condition: where the vehicle is in park, where a gradient at a vehicle location is large, where the reception condition of GPS signal changes, where brightness around the vehicle changes, and the like cases.

Description

  The present invention relates to a navigation device for a vehicle and a method for recording a travel locus of a vehicle in the navigation device.

  Conventionally, in a navigation device that records a vehicle's travel locus and performs map matching, the vehicle's travel locus is approximated by a straight line, and when it is determined that the vehicle is turning right or left, an intersection that extends a straight road before and after is recorded as locus data. Thus, there is known one that reduces the amount of data (see Patent Document 1).

Japanese Patent Laid-Open No. 6-102052

  In the conventional navigation apparatus as described above, only the intersection of the straight road before and after the right / left turn is recorded as the trajectory data, and the actual movement of the vehicle at the right / left turn is not recorded. Therefore, although it is suitable for recording the traveling trajectory of the vehicle at the intersection having a simple shape, the trajectory data accurately reflecting the movement of the vehicle cannot be recorded at the intersection having a complicated shape. This may lead to a decrease in map matching accuracy.

The navigation device according to the present invention records storage means for storing map data, position detection means for detecting an absolute estimated position of a vehicle that does not depend on map data, and a locus of the absolute estimated position detected by the position detection means. Trajectory recording means, determination means for determining whether or not the absolute estimated position satisfies a predetermined recording condition, based on detection results by various sensors for detecting the behavior of the vehicle or the surrounding situation of the vehicle, and determination means And a recording control means for recording the locus of the absolute estimated position in the locus recording means except for the absolute estimated position determined as not satisfying the recording condition.
A traveling locus recording method according to the present invention is a method for recording a traveling locus of a vehicle in a navigation device for a vehicle, and the navigation device detects an absolute estimated position of the vehicle independent of map data, and determines the behavior of the vehicle or the vehicle. Based on the detection results of various sensors for detecting the surrounding situation, it is determined whether or not the absolute estimated position satisfies a predetermined recording condition, and the absolute estimated position that is determined not to satisfy the recording condition is excluded. Record the locus of the estimated position.

  According to the present invention, when recording a travel locus of a vehicle, the movement of the vehicle can be accurately reflected even at an intersection having a complicated shape while reducing the amount of data.

It is a block diagram which shows the structure of the navigation apparatus by one Embodiment of this invention. It is a figure which shows an example of the operation | movement which records the driving | running | working locus of a vehicle. It is a figure which shows an example of the map matching based on the recorded driving | running track. It is a figure which shows another example of the map matching based on the recorded driving | running track. It is a flowchart of the process by one Embodiment of this invention.

  FIG. 1 shows the configuration of a navigation device according to an embodiment of the present invention. The navigation device 1 is used by being mounted on a vehicle, and includes a control unit 10, a vibration gyro 11, a vehicle speed sensor 12, a gradient sensor 13, a light sensor 14, a GPS (Global Positioning System) sensor 15, a VICS (Vehicle Information). and Communication System) (registered trademark) information receiving unit 16, hard disk drive (HDD) 17, display monitor 18 and input device 19.

  The control unit 10 includes a microprocessor, various peripheral circuits, a RAM, a ROM, and the like, and executes various processes based on a control program and map data recorded in the HDD 17. Various processes for guiding the host vehicle to the destination are executed by the process performed by the control unit 10. For example, destination search processing when setting a destination, search processing of a recommended route to the set destination, detection processing of the current position of the host vehicle, various image display processing, voice output processing during route guidance Etc. are executed. In addition, when displaying the vehicle position on the map, a map matching process described later is executed by the control unit 10.

  The vibration gyro 11 is a sensor for detecting the angular velocity of the host vehicle. Based on the angular velocity detected by the vibration gyro 11, the traveling direction of the host vehicle is obtained by the processing of the control unit 10. That is, the vibration gyro 11 is a traveling direction sensor for detecting the traveling direction of the host vehicle. The vehicle speed sensor 12 is a sensor for detecting the vehicle speed of the host vehicle, that is, the traveling speed. By detecting the motion state of the host vehicle at predetermined time intervals using the vibration gyro 11 and the vehicle speed sensor 12, the position movement amount of the host vehicle is obtained, and thereby the current position of the host vehicle is detected.

The gradient sensor 13 is a sensor for detecting the gradient of the traveling point of the host vehicle. The gradient sensor 13 can be realized by, for example, an acceleration sensor that detects acceleration applied to the host vehicle in the vertical direction. In this case, when the vertical acceleration of the host vehicle detected by the acceleration sensor is a and the gravitational acceleration is g, the gradient angle θ can be expressed as θ = cos ⁻¹ (a / g). In addition, you may utilize things other than an acceleration sensor as the gradient sensor 13, for example, a barometric pressure sensor.

  The optical sensor 14 is a sensor for detecting the brightness around the host vehicle. The output of the optical sensor 14 is used for auto light control of the host vehicle in addition to the processing described below executed in the control unit 10. That is, the headlight of the own vehicle is turned off when the brightness detected by the optical sensor 14 is equal to or higher than a predetermined value, and is turned on when the brightness is lower than the predetermined value. Auto-light control is performed in the control device.

  The GPS sensor 15 is a sensor for receiving a GPS signal wirelessly transmitted from a GPS satellite. The GPS signal includes information on the position and transmission time of the GPS satellite that transmitted the GPS signal as information for obtaining the position of the host vehicle and the current time. Therefore, by receiving GPS signals from a predetermined number or more of GPS satellites, the current position and current time of the host vehicle can be calculated based on these pieces of information.

  The behavior and surrounding conditions of the host vehicle are detected by the various sensors such as the vibration gyro 11, the vehicle speed sensor 12, the gradient sensor 13, the optical sensor 14, and the GPS sensor 15 described above. That is, the vibration gyro 11, the vehicle speed sensor 12, and the GPS sensor 15 are sensors for detecting behaviors such as the traveling direction, traveling speed, and current position of the host vehicle. On the other hand, the gradient sensor 13 and the optical sensor 14 are sensors for detecting surrounding conditions of the host vehicle such as the gradient of the travel point and the brightness of the surroundings. The reception status of the GPS signal by the GPS sensor 15 depends on the surrounding conditions of the host vehicle. That is, the GPS sensor 15 serves as both a sensor for detecting the behavior of the host vehicle and a sensor for detecting the surrounding situation of the host vehicle.

  The VICS information receiving unit 16 receives VICS information transmitted from the VICS center to the navigation device 1. When the VICS information receiving unit 16 receives this VICS information, various road traffic information including traffic jam information is acquired in the navigation device 1. The VICS information received by the VICS information receiving unit 16 is output to the control unit 10 and used for displaying traffic jam information, searching for a recommended route, and the like.

  The transmission of VICS information from the VICS center to the navigation device 1 is performed mainly by radio wave beacons installed on highways, optical beacons installed mainly on general roads, or FM multiplex broadcasting. . The radio wave beacon and the optical beacon transmit VICS information locally to the vehicle passing near the installation point by radio waves or light (infrared rays). In contrast, FM multiplex broadcasting can transmit VICS information to a relatively wide area.

  The HDD 17 is a non-volatile recording medium that can store and hold recorded data. Various data including the control program and map data are recorded in the HDD 17. These data recorded in the HDD 17 are read out under the control of the control unit 10 as necessary, and are used for various processes and controls executed by the control unit 10.

  The map data recorded on the HDD 17 includes route calculation data, road data, and background data. The route calculation data is data used when searching for a recommended route to the destination. The road data is data representing the shape and type of the road. In the map data, the minimum unit of each road is called a link. That is, each road in the map data is composed of a plurality of links. The background data is data representing the background of the map. Note that the background of the map is various components other than roads existing on the map. For example, rivers, railways, green zones, various structures, etc. are represented by background data.

  The map data includes POI (Point Of Interest) data related to various types of facilities. For example, information on types and positions of various facilities such as accommodation facilities such as inns and hotels, restaurants, gas stations, and convenience stores is recorded in the POI data. Based on this POI data, an icon corresponding to the type of facility is displayed on the map.

  The display monitor 18 is a device for displaying various screens in the navigation device 1 and is configured using a liquid crystal display or the like. For example, a map around the vehicle position is displayed on the display monitor 18. The contents of the screen displayed on the display monitor 18 are determined by screen display control performed by the control unit 10. The display monitor 18 is installed at a position where the user can easily see, for example, on the dashboard of the host vehicle or in the instrument panel.

  The input device 19 is a device for a user to perform various input operations for operating the navigation device 1, and includes various input switches. The user operates the input device 19 to input, for example, the name of a facility or point desired to be set as a destination, select a destination from registered locations registered in advance, or display a map in an arbitrary direction. Or scroll. The input device 19 can be realized by an operation panel, a remote controller, or the like. Alternatively, the input device 19 may be a touch panel integrated with the display monitor 18.

  When the user operates the input device 19 to set a destination, the navigation device 1 performs a predetermined algorithm calculation based on the above-described route calculation data, using the current position of the host vehicle as the departure location. Route search from to the destination. The route obtained by this route search is set as a recommended route to the destination. When the recommended route is set in this way, the recommended route is displayed on the map separately from other roads by a method such as using a color different from that of the other roads. Thus, the user can easily recognize the recommended route on the map displayed on the display monitor 18. In addition, the navigation device 1 guides the host vehicle by instructing the traveling direction by an image or voice to the user so that the host vehicle can travel according to the recommended route. In this way, route guidance to the destination is performed.

  Next, map matching processing executed in the navigation device 1 will be described. As described above, the navigation device 1 detects the position of the host vehicle at predetermined time intervals using the vibration gyro 11, the vehicle speed sensor 12, and the GPS sensor 15, and uses the track (history) of the host vehicle position as the travel track of the host vehicle. Records in the HDD 17. A map matching process for specifying a link to be a map matching target based on the traveling locus of the vehicle recorded in the HDD 17 and the position and shape of each link in the map data recorded in the HDD 17 in advance is performed. Do. The vehicle position is corrected using the link specified by the map matching process as a map matching target road. Thereby, the own vehicle position can be corrected according to the road, and the corrected own vehicle position can be displayed on the map.

  Note that the vehicle position before correction by the map matching process, that is, the vehicle position detected in the navigation device 1 and recorded in the HDD 17, is not affected by the previous map matching result, and is vibrated as described above. This is estimated based on the detection results of the gyro 11, the vehicle speed sensor 12, and the GPS sensor 15. In other words, the vehicle position that does not depend on the map data is used in the map matching process. Hereinafter, the vehicle position before correction that does not depend on the map data is referred to as an absolute estimated position.

  When the navigation apparatus 1 records the absolute estimated position trajectory representing the travel trajectory of the host vehicle in the HDD 17 as described above, the navigation apparatus 1 is detected every predetermined time based on the detection results of the various sensors as described above. It is determined whether or not the absolute estimated position satisfies a predetermined recording condition. Based on the determination result, only the absolute estimated position determined to satisfy the recording condition is recorded in the HDD 17 as the feature point indicating the feature of the traveling road of the host vehicle. That is, the locus of the absolute estimated position is recorded in the HDD 17 except for those determined not to satisfy the recording conditions as the feature points.

  The determination as to whether or not the absolute estimated position satisfies the recording condition as a feature point can be made by any of the following methods (1) to (4), for example.

(1) When the vehicle is turning or stopped The navigation device 1 turns the vehicle when the absolute estimated position is detected based on the detection result of one or both of the vibration gyro 11 and the vehicle speed sensor 12. Alternatively, it is determined whether or not it has been stopped. As a result, if the host vehicle is turning or stopped, it is determined that the absolute estimated position detected at that time satisfies the recording condition, and the absolute estimated position is recorded in the HDD 17 as a feature point. On the other hand, if the host vehicle is not turning or stopped when the absolute estimated position is detected, that is, if the host vehicle is traveling straight, it is determined that the absolute estimated position does not satisfy the recording condition, and the HDD 17 Do not record on.

(2) When the gradient of the travel point of the vehicle is large The navigation device 1 determines that the gradient detected by the gradient sensor 13 at the travel point of the host vehicle when the absolute estimated position is detected is greater than or equal to a predetermined value, for example, a gradient value of 10%. It is determined whether this is the case. As a result, if the gradient of the travel point of the host vehicle is greater than or equal to a predetermined value, it is determined that the absolute estimated position detected at the travel point satisfies the recording condition, and the absolute estimated position is used as a feature point in the HDD 17. Record. On the other hand, when the gradient of the travel point of the host vehicle is less than the predetermined value, it is determined that the absolute estimated position detected at the travel point does not satisfy the recording condition and is not recorded in the HDD 17.

(3) When the reception state of the GPS signal has changed The navigation device 1 determines whether or not the reception state of the GPS signal by the GPS sensor 15 has changed when the absolute estimated position is detected. As a result, when the reception state of the GPS signal changes, it is determined that the absolute estimated position satisfies the recording condition and is recorded in the HDD 17. That is, when the GPS signal changes from the reception state to the non-reception state, or conversely, when the GPS signal changes from the non-reception state to the reception state, the absolute estimated position detected at the closest timing from that point Is recorded in the HDD 17. On the other hand, when the reception state of the GPS signal does not change, it is determined that the detected absolute estimated position does not satisfy the recording condition and is not recorded in the HDD 17.

(4) When the brightness around the vehicle changes The navigation device 1 determines whether the change in the brightness around the host vehicle detected by the optical sensor 14 when the absolute estimated position is detected is greater than or equal to a predetermined value. Judge whether or not. As a result, when the brightness around the host vehicle changes by a predetermined value or more, the absolute estimated position detected at the closest timing from that time is recorded in the HDD 17 as a feature point. On the other hand, if the change in brightness around the host vehicle is less than the predetermined value, it is determined that the detected absolute estimated position does not satisfy the recording condition, and is not recorded in the HDD 17. Note that the amount of change in brightness used for this determination is preferably the same as that of the above-described auto light control. In this way, when the headlight of the host vehicle changes from the unlit state to the lit state or from the lit state to the unlit state by auto light control, the absolute estimated position can be recorded in the HDD 17 according to the change. .

  According to the determination methods (1) to (4) as described above, it is determined whether or not the detected absolute estimated position satisfies the recording condition as the feature point, and the absolute estimated position is determined according to the determination result. It is possible to determine whether or not to record the locus on the HDD 17. Any of these determination methods may be used alone, or a plurality may be used in combination. Furthermore, a determination method other than that described above may be used to determine whether or not the absolute estimated position satisfies a recording condition as a feature point.

  FIG. 2 shows an example of the operation of recording the history of the absolute estimated position of the host vehicle using the method (1) among the determination methods described above. In FIG. 2, the host vehicle moves from the position indicated by reference numeral 21 to the position indicated by reference numeral 22, and at this time, the absolute estimated positions indicated by P1 to P26 are detected by the navigation device 1 every predetermined time.

  While the absolute estimated positions P1 to P8 are detected, the host vehicle turns clockwise from the position 21 and moves on the road from outside the road. Therefore, as described above, the absolute estimated positions P1 to P8 are determined to satisfy the recording condition as the feature points, and are recorded in the HDD 17.

  While the absolute estimated positions P9 to P11 are detected, the host vehicle is traveling straight on the road and is neither turning nor stopping. Therefore, it is determined that the absolute estimated positions P9 to P11 do not satisfy the recording conditions as feature points, and are not recorded in the HDD 17.

  While the absolute estimated positions P12 to P14 are detected, the host vehicle is turning right on the road. In this case, since it is determined that the host vehicle is turning, the absolute estimated positions P12 to P14 are determined to satisfy the recording condition as the feature points and are recorded in the HDD 17.

  While the absolute estimated positions P15 to P17 are detected, the host vehicle is traveling straight on the road and is neither turning nor stopping. Therefore, it is determined that the absolute estimated positions P15 to P17 do not satisfy the recording conditions as the feature points, and are not recorded in the HDD 17.

  While the absolute estimated positions P18 to P23 are detected, the vehicle turns left on the road, and then turns right. In this case, since it is determined that the host vehicle is turning, the absolute estimated positions P18 to P23 are determined to satisfy the recording condition as the feature points and are recorded in the HDD 17.

  While the absolute estimated positions P24 to P26 are detected, the host vehicle is traveling straight on the road and is neither turning nor stopping. Therefore, it is determined that the absolute estimated positions P24 to P26 do not satisfy the recording conditions as the feature points, and are not recorded in the HDD 17.

  As described above, it is determined whether or not the recording conditions as the feature points are satisfied for each of the absolute estimated positions P1 to P26, and the absolute estimated positions P1 to P8 and P12 to which are determined to satisfy the recording conditions are determined. P14 and P18 to P23 are recorded in the HDD 17.

  When the locus of the absolute estimated position determined to be a feature point is recorded in the HDD 17, the recording conditions corresponding to the absolute estimated position are recorded in combination. That is, the navigation device 1 includes information indicating the absolute estimated position, and information indicating which recording condition the absolute estimated position satisfies among the recording conditions in each of the determination methods such as (1) to (4) described above. Are associated with each other and recorded in the HDD 17 as feature point data.

  Based on the feature point data recorded in the HDD 17 in this way, map matching processing in the navigation device 1 is performed. Specific examples thereof will be described below with reference to FIGS.

  FIG. 3 is a diagram showing an example of map matching based on the locus of the absolute estimated position recorded in the HDD 17 as the feature point. In FIG. 3, absolute estimated positions P31 to P35 are recorded as feature points in the HDD 17, and stop information indicating that the host vehicle has stopped is included in the absolute estimated positions P31 to P33 among the absolute estimated positions P34, It is assumed that turning information indicating that the host vehicle is turning is associated with P35. It is assumed that there are roads 31 and 32 adjacent to each other, of which road 31 is provided with a display mark 33 indicating no traffic jam, and road 32 is provided with a display mark 34 indicating traffic jam. The display marks 33 and 34 are determined based on the VICS information received by the VICS information receiving unit 16.

  From the absolute estimated positions P31 to P33 and the stop information associated therewith, it can be seen that the host vehicle frequently stops at a place other than the intersection when traveling on the road. Therefore, it can be estimated that the own vehicle traveled on the congested road 32 instead of the congested road 31 and reached the position 23. By performing map matching reflecting such estimation results, it is possible to reliably identify the link representing the road 32 as the map matching target road and correct the vehicle position accordingly.

  FIG. 4 is a diagram showing another example of map matching based on the locus of the absolute estimated position recorded in the HDD 17 as the feature point. In FIG. 4, absolute estimated positions P41 and P42 are recorded in the HDD 17 as feature points. Among these, the absolute estimated position P41 includes reception change information indicating that the GPS signal has changed from the reception state to the non-reception state; It is assumed that the brightness change information indicating that the brightness of the surroundings of the host vehicle has changed by a predetermined value or more and the headlight has changed from the off state to the on state is associated. On the other hand, at the absolute estimated position P42, the reception change information indicating that the GPS signal has changed from the non-reception state to the reception state, and the brightness of the surroundings of the host vehicle change by a predetermined value or more, and the headlight is turned off from the on state. Assume that brightness change information indicating that a state has been reached is associated. Further, it is assumed that there are a road 41 and a road 42 that are adjacent to each other, and a tunnel 43 exists on the road 41.

  Based on the absolute estimated positions P41 and P42 and the reception change information and brightness change information associated therewith, the vehicle passes through a structure that shields the sky, such as a tunnel, while traveling on the road. You can see that Therefore, it can be estimated that the host vehicle travels on the road 41 where the tunnel 43 exists, not the road 42 where the tunnel 43 does not exist, and reaches the position 24. By performing map matching reflecting such estimation results, it is possible to reliably specify the link representing the road 41 as the map matching target road and correct the vehicle position accordingly.

  In addition, you may perform the map matching process by methods other than the specific example demonstrated above. For example, when gradient information indicating the gradient of the travel point is recorded in the feature point data in association with the absolute estimated position, a link corresponding to a road whose gradient is closer to the gradient information value among a plurality of adjacent roads Can be preferentially used as a map matching target road. In addition to this, it is possible to perform map matching processing in accordance with the feature of the absolute estimated position indicated by the feature point data.

  FIG. 5 shows a flowchart of the processing according to the embodiment of the present invention as described above. This flowchart is repeatedly executed at predetermined time intervals by the control unit 10 in the navigation device 1.

  In step S <b> 10, the control unit 10 detects the absolute estimated position of the host vehicle based on the detection results of the vibration gyro 11, the vehicle speed sensor 12, and the GPS sensor 15. This absolute estimated position does not depend on the map data as described above.

  In step S <b> 20, the control unit 10 acquires sensor information output from each of the vibration gyro 11, the vehicle speed sensor 12, the gradient sensor 13, the optical sensor 14, and the GPS sensor 15. This sensor information includes information indicating a detection result by each sensor.

  In step S30, the control unit 10 determines whether the absolute estimated position detected in step S10 satisfies a predetermined recording condition based on the sensor information acquired in step S20. This determination can be performed by determining whether or not at least one of the recording conditions as described in each of the determination methods (1) to (4) is satisfied. If any recording condition is satisfied, the process proceeds to step S40, and if neither recording condition is satisfied, the process proceeds to step S50.

  In step S40, the control unit 10 records the absolute estimated position detected in step S10 on the HDD 17 as a feature point. At this time, information indicating the type of recording condition determined to be satisfied in step S30 is recorded in the HDD 17 in association with the absolute estimated position. Thereby, the feature point data in which the absolute estimated position detected in step S10 and the corresponding recording condition are associated with each other is recorded in the HDD 17 except for the absolute estimated position determined not to satisfy the recording condition in step S30.

  By repeatedly executing the processes in steps S10 to S40 as described above at predetermined time intervals, the locus of the absolute estimated position that satisfies the recording condition is recorded in the HDD 17.

  In step S50, the control unit 10 determines whether or not a plurality of types of feature points have been recorded on the HDD 17, based on the feature point data recorded on the HDD 17 by the processing of step S40 executed so far. The type of feature point here refers to the type of recording condition associated with the absolute estimated position in each feature point data, that is, the type of recording condition determined to satisfy the absolute estimated position in step S30. . If multiple types of feature points are recorded in the HDD 17, the control unit 10 proceeds to step S60 in order to execute the map matching process. On the other hand, when a plurality of types of feature points are not recorded in the HDD 17, the control unit 10 returns to step S10 and continues to detect the absolute estimated position. By executing the process of step S50 as described above, the timing for performing the map matching process in the navigation device 1 is determined.

  In step S60, the control unit 10 searches for a map matching candidate link to be set on the map matching target road based on the map data recorded in the HDD 17 and the locus of the absolute estimated position indicated by each feature point data. Here, the locus of the absolute estimated position is compared with the position and shape of each link in the map data, and a link whose degree of matching is within a predetermined range is searched for as a map matching candidate. As a result, when a unique link is searched as a map matching candidate, the link is set as a map matching target road. Thereby, the map matching target road is specified. On the other hand, when a plurality of links are searched as map matching candidates, the map matching target road is not set and the map matching candidates are left as they are.

  Note that in the search for map matching candidates in step S60, one of the links is preferentially made a map matching candidate based on the type of feature point, that is, the recording condition associated with the absolute estimated position in each feature point data. Is preferred. For example, as described above with reference to FIG. 3, when the absolute estimated position that satisfies the recording condition that the host vehicle is stopped is continuously recorded, the link of the congested road is given priority. To map matching candidates. Alternatively, as described above with reference to FIG. 4, when an absolute estimated position that satisfies the recording condition such as a change in the reception state of the GPS signal or a change in brightness around the host vehicle is recorded, a tunnel exists. The road link to be used is preferentially a map matching candidate. Besides this, various links according to the recording conditions can be searched as map matching candidates.

  In the search for the map matching candidate as described above, the weight for each absolute estimated position may be changed to reflect the current situation where the host vehicle is placed. For example, an evaluation value corresponding to the relationship between the corresponding recording condition and the current situation is calculated for each absolute estimated position using a preset evaluation function. In this evaluation function, for example, if the current time zone is night, the recording condition based on the detection result of the optical sensor 14, that is, the recording according to (4) above, that the change in brightness around the host vehicle is equal to or greater than a predetermined value. Regarding conditions, an evaluation value lower than other recording conditions can be calculated. In addition, when the host vehicle is traveling in a central area where high-rise buildings are densely packed, the recording condition based on the detection result of the GPS sensor 15, that is, the recording condition of the above (3) that the reception state of the GPS signal has changed. With respect to, an evaluation value lower than other recording conditions can be calculated. A map matching candidate may be searched after weighting each absolute estimated position based on the evaluation value thus calculated.

  In step S70, the control unit 10 determines whether or not a unique map matching candidate has been searched in step S60, that is, whether or not a map matching target road has been set. When the only map matching candidate is searched, the control unit 10 proceeds to step S80. On the other hand, when the only map matching candidate is not searched, that is, when a plurality of map matching candidates are searched, or when no map matching candidate is searched, the control unit 10 returns to step S10 to Continue to detect the estimated position. In addition, when a plurality of map matching candidates are searched, it is preferable to exclude other links from the next processing target so as not to be map matching candidates.

  In step S80, the control unit 10 corrects the vehicle position according to the link of the only map matching candidate searched in step S60, that is, the link of the map matching target road.

  In step S90, the control unit 10 displays the vehicle position corrected in step S80 on the map. Thereby, the own vehicle position is corrected according to the road, and the own vehicle position is displayed on the road on the display monitor 16.

  In step S <b> 100, the control unit 10 erases the feature point data recorded so far from the HDD 17. Thereby, when the map matching target road is specified by the process of step S60, the locus of the absolute estimated position recorded in the HDD 17 so far is deleted. If step S100 is performed, the control part 10 will return to step S10, and will continue detection of an absolute estimated position.

  According to the embodiment described above, the following operational effects are obtained.

(1) The navigation device 1 detects the absolute estimated position of the host vehicle independent of the map data stored in the HDD 17 by the process of the control unit 10 (step S10). And based on the detection result by the various sensors of the vibration gyro 11, the vehicle speed sensor 12, the gradient sensor 13, the optical sensor 14, and the GPS sensor 15, it is determined whether or not the detected absolute estimated position satisfies a predetermined recording condition ( In step S30), the locus of the absolute estimated position is recorded in the HDD 17 except for the absolute estimated position determined not to satisfy the recording condition (step S40). Since it did in this way, when recording the position log | history of the own vehicle, the movement of the own vehicle can be correctly reflected even if it is an intersection of complicated shape, reducing data amount.

(2) In step S30, the control unit 10 turns or stops the host vehicle when the absolute estimated position is detected in step S10 based on the detection result of at least one of the vibration gyro 11 and the vehicle speed sensor 12. When it is determined whether or not the vehicle has been turned or stopped, it can be determined that the absolute estimated position satisfies the recording condition. Thereby, the locus of the absolute estimated position when there is a characteristic in the behavior of the host vehicle can be recorded.

(3) In step S30, the control unit 10 can determine that the absolute estimated position satisfies the recording condition when the gradient of the traveling point of the host vehicle detected by the gradient sensor 13 is greater than or equal to a predetermined value. In step S30, the control unit 10 can determine that the absolute estimated position satisfies the recording condition when the reception state of the GPS signal by the GPS sensor 15 changes. Further, in step S30, the control unit 10 can determine that the absolute estimated position satisfies the recording condition when the change in brightness around the host vehicle detected by the optical sensor 14 is equal to or greater than a predetermined value. Thereby, the locus of the absolute estimated position when there is a feature in the surrounding situation of the host vehicle can be recorded.

(4) The navigation device 1 specifies a map matching target road based on the map data stored in the HDD 17 and the locus of the absolute estimated position recorded in the HDD 17 in step S40 by the processing of the control unit 10 ( In step S60, the position of the host vehicle is corrected in accordance with the map matching target road (step S80). Thereby, the map matching process using the locus of the absolute estimated position can be realized.

(5) When recording the locus of the absolute estimated position in the HDD 17 in step S40, the control unit 10 records the recording conditions corresponding to each absolute estimated position in association with each other. In step S60, the weighting for each absolute estimated position when the map matching target road is specified can be changed based on the recording condition recorded for each absolute estimated position. Thereby, the map matching process reflecting the current situation can be realized.

(6) Moreover, the control part 10 determines whether several types of feature points were recorded on HDD17 based on the recording conditions recorded for every absolute estimated position (step S50). The timing for specifying the map matching target road is determined by determining whether or not to execute the process of step S60 according to the determination result. Since it did in this way, a map matching process can be performed at an appropriate timing and a map matching object road can be specified by it.

(7) The control unit 10 determines whether or not a map matching target road has been identified in step S60 (step S70), and when an affirmative determination is made, the locus of the absolute estimated position that has been recorded in the HDD 17 up to that point is determined. Erasing is performed (step S100). Since it did in this way, it can prevent that unnecessary data are accumulate | stored in HDD17 and a capacity | capacitance is pressed.

  In the above embodiment, when it is determined in step S50 that a plurality of types of feature points have been recorded in the HDD 17, the processing of step S60 is executed to identify the map matching target road. The timing for specifying the map matching target road may be determined using the above condition. For example, when at least one feature point indicating that the host vehicle has turned and one feature point indicating that a GPS signal has been recorded are recorded in the HDD 17, the process of step S <b> 60 is executed to execute the map matching target road May be specified. Any method may be used as long as the timing for specifying the map matching target road is determined based on the recording condition recorded for each absolute estimated position.

  Alternatively, the timing for specifying the map matching target road may be determined regardless of the recording condition recorded for each absolute estimated position. For example, the map matching target road may be specified by executing the process of step S60 when a predetermined number or more of feature points are recorded.

  In the embodiment described above, the corrected position of the host vehicle is displayed on the map on the display monitor 18, but the corrected position of the host vehicle may be used for other processing. For example, the corrected vehicle position according to the present invention can also be used in lane keeping control for controlling the vehicle to travel in the lane, curve assist control for decelerating the vehicle before a curve, or the like. .

  The embodiment and various modifications described above are merely examples, and the present invention is not limited to these contents as long as the features of the invention are not impaired. Moreover, you may use the said embodiment and a modification in combination.

1: navigation device, 10: control unit, 11: vibration gyro, 12: vehicle speed sensor,
13: Gradient sensor, 14: Optical sensor, 15: GPS sensor, 16: VICS information receiver, 17: HDD, 18: Display monitor, 19: Input device

Claims (10)

Storage means for storing map data;
Position detecting means for detecting an absolute estimated position of the vehicle independent of the map data;
Trajectory recording means for recording the trajectory of the absolute estimated position detected by the position detecting means;
Determination means for determining whether or not the absolute estimated position satisfies a predetermined recording condition based on detection results by various sensors for detecting the behavior of the vehicle or the surrounding situation of the vehicle;
A navigation apparatus comprising: a recording control unit that records a locus of the absolute estimated position in the locus recording unit, excluding the absolute estimated position determined by the determining unit as not satisfying the recording condition. The navigation device according to claim 1, wherein
The sensor includes at least one of a traveling direction sensor for detecting a traveling direction of the vehicle and a speed sensor for detecting a traveling speed of the vehicle,
Whether the vehicle has turned or stopped when the absolute estimated position is detected by the position detection unit based on a detection result of at least one of the traveling direction sensor and the speed sensor. And determining that the absolute estimated position satisfies the recording condition when it is determined that the vehicle is turning or stopped. The navigation device according to claim 1 or 2,
The sensor includes a gradient sensor for detecting a gradient of a travel point of the vehicle,
The navigation apparatus according to claim 1, wherein the determination unit determines that the absolute estimated position satisfies the recording condition when a gradient of a travel point of the vehicle detected by the gradient sensor is equal to or greater than a predetermined value. In the navigation device according to any one of claims 1 to 3,
The sensor includes a radio signal receiving sensor for receiving a radio signal for detecting the position of the vehicle,
The navigation device according to claim 1, wherein the determination unit determines that the absolute estimated position satisfies the recording condition when a reception state of the wireless signal by the wireless signal reception sensor changes. The navigation device according to any one of claims 1 to 4,
The sensor includes an optical sensor for detecting brightness around the vehicle,
The determination unit determines that the absolute estimated position satisfies the recording condition when a change in brightness around the vehicle detected by the optical sensor is greater than or equal to a predetermined value. . The navigation device according to any one of claims 1 to 5,
Map matching means for specifying a map matching target road based on the map data and the locus of the absolute estimated position recorded in the locus recording means;
A navigation device, further comprising: a correction unit that corrects the position of the vehicle in accordance with the map matching target road specified by the map matching unit. The navigation device according to claim 6, wherein
The recording control means records the recording conditions corresponding to the absolute estimated positions in association with each other when the locus of the absolute estimated positions is recorded in the locus recording means,
The navigation apparatus according to claim 1, wherein the map matching unit changes the weight for each absolute estimated position when specifying the map matching target road based on the recording condition recorded for each absolute estimated position. The navigation device according to claim 6 or 7,
The recording control means records the recording conditions corresponding to the absolute estimated positions in association with each other when the locus of the absolute estimated positions is recorded in the locus recording means,
The navigation device characterized in that the map matching means determines a timing for specifying the map matching target road based on the recording condition recorded for each absolute estimated position. The navigation device according to any one of claims 6 to 8,
The navigation apparatus according to claim 1, wherein when the map matching target road is specified by the map matching unit, the recording control unit erases the track of the absolute estimated position recorded in the track recording unit. A method of recording a travel locus of a vehicle in a vehicle navigation device,
The navigation device detects the absolute estimated position of the vehicle independent of map data,
The navigation device determines whether the absolute estimated position satisfies a predetermined recording condition based on detection results by various sensors for detecting the behavior of the vehicle or the surrounding situation of the vehicle,
A travel trajectory recording method, wherein the trajectory of the absolute estimated position is recorded by the navigation device except for the absolute estimated position determined not to satisfy the recording condition.

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