JP2006275619A - Altitude calculation system and navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire an absolute altitude from a map database by linking with information reception using DSRC. <P>SOLUTION: The map database 20 where a navigation system 1 stores comprises latitude, longitude, and altitude values at the positions of tollhouses of a toll road where ETC devices are provided side by side. The navigation system 1 can calculate the altitude of the present location, by using contents detected by a 3D gyro sensor 4 by a position detection processing portion 6, a vehicle-speed pulse signal fetched from a vehicle through a vehicle-side connector 5, and so on. Moreover, when the navigation system receives an ETC signal by an ETC signal receiver 3, the navigation system 1 specifies a tollhouse near the place of its reception from the map database 20, acquires an altitude value of the specified tollhouse as an implicit altitude, and corrects the calculated altitude based on the implicit altitude. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention obtains a value that becomes an absolute altitude every time a predetermined place is passed, corrects the calculated altitude based on the absolute altitude, and uses the altitude obtained by the altitude calculating apparatus. The present invention relates to a navigation device that realizes map matching processing.

  2. Description of the Related Art Conventionally, navigation devices that are installed in vehicles and perform route guidance to a destination have become widespread. In general, a navigation device receives position information using GPS (Global Positioning System), calculates a current vehicle position based on an azimuth sensor provided in the navigation device, an axle pulse acquired from the vehicle, etc. The directions of When the calculated current vehicle position is displayed on the map, the calculated vehicle position may not match the road position on the map due to a calculation error or the like. A map matching process is performed so as to be placed on a rough road.

  Recently, in order to improve the accuracy of the map matching process, a function to obtain the altitude of the vehicle position in addition to the two-dimensional position (latitude and longitude) of the vehicle is provided, and the map matching process is also performed using the obtained altitude. There are also navigation devices to do. For example, when map matching is performed in a place where an elevated road and a road under the elevated road are parallel, it is possible to specify which road to perform map matching using the altitude of the vehicle position. It is also possible to determine whether or not to perform the map matching process itself based on the altitude.

  In order to perform map matching processing using altitude, the navigation device cannot directly determine the absolute altitude, so it depends on altitude information that can be acquired from GPS, or using a sensor such as a 3D gyroscope. Altitude calculation will be performed.

In Patent Document 1 below, current position calculation is performed by receiving position information including altitude information transmitted by DSRC and using it for map matching processing by DSRC (Dedicated Short Range Communication). An apparatus is disclosed.
JP 2001-289653 A

  For high-accuracy map matching processing, when the navigation device acquires altitude information from the GPS, the altitude information that can be acquired from the current GPS for position determination of the vehicle has large variations in information and is insufficient in accuracy. Therefore, there is a problem that stable and highly accurate map matching processing cannot be performed.

  In addition, in order to obtain altitude by providing a sensor such as a 3D gyro in the navigation device, the inclination angle (vehicle pitch angle) of the vehicle traveling direction with respect to the horizontal direction is detected by the sensor, and the distance the vehicle has moved is calculated and detected The altitude is calculated using a trigonometric function based on the tilt angle and the calculated movement distance. The detection by each sensor always includes a detection error, and a calculation error accompanying rounding up of the number of digits occurs even in the calculation processing stage, so the detection error and the calculation error are always accumulated in the calculated altitude, There is a problem that the absolute altitude includes an error.

  In addition, since the navigation device has no means for obtaining the absolute altitude, it cannot grasp how much error the obtained altitude contains with respect to the absolute altitude, and the obtained altitude is calibrated (corrected). There is a problem that cannot be performed accurately. That is, as the current calibration processing for altitude, an absolute altitude value is included in advance for a specific location in map data, and if there is an altitude value at a map-matched position, the altitude value It is a method of performing calibration using For this reason, an accurate altitude that should be obtained before map matching is obtained after map matching, and there is a problem that calibration accuracy cannot be improved and high-precision map matching processing cannot be performed.

  Furthermore, in order to use the current position calculation device according to Patent Document 1, first, a function that can transmit altitude information of the location where the device is installed is provided in the infrastructure device installed on the road that communicates by DSRC. Therefore, a large-scale specification change including infrastructure is required, and there is a problem that it cannot be easily introduced only by a specification change on the navigation device side.

The present invention has been made in view of such circumstances, and includes the absolute altitude of a place where information is transmitted by DSRC in map data, and is linked to the position where information is received from DSRC. It is an object of the present invention to provide an altitude calculation device that can accurately calculate the calculated altitude without changing the infrastructure equipment specifications.
It is another object of the present invention to provide an altitude calculation apparatus that can calculate altitude with high accuracy by performing altitude calculation using the altitude as a reference value when calibration is performed.

It is another object of the present invention to provide an altitude calculation apparatus that can calculate an error in altitude calculated when calibration is performed a plurality of times.
Furthermore, an object of the present invention is to provide a navigation device that can implement a map matching process with higher accuracy than the prior art by using the altitude calculated by the altitude calculating device or the calibrated altitude.

  In order to solve the above-described problem, the altitude calculation apparatus according to the first invention includes a movement distance calculation means for calculating a movement distance, an inclination angle detection means for detecting an inclination angle with respect to a horizontal line in the movement direction, and the movement distance calculation means. In an altitude calculation device comprising an altitude calculation means for calculating an altitude based on the calculated moving distance and the tilt angle detected by the tilt angle detection means, a place where information transmitted by dedicated narrow area communication can be received Corresponding map database having the altitude of the place, receiving means for receiving information through dedicated narrow area communication, and specifying means for specifying the received altitude from the map database when the receiving means receives the information And altitude correcting means for correcting the altitude calculated by the altitude calculating means based on the altitude specified by the specifying means.

  In the first invention, a map database having the altitude of the location is prepared by associating the information transmitted by the dedicated narrow-area communication with a place where the information can be received, and the dedicated narrow-area communication has several tens of communication available. Using the characteristic that information cannot be received unless it is located within a narrow range of m units, the location of the dedicated narrow area communication and its altitude are identified from the map database as information is received through the dedicated narrow area communication. Can be obtained. As a result, the altitude calculated for the location can be accurately corrected based on the acquired absolute altitude. Further, in the present invention, since existing infrastructure equipment is used, it is not necessary to change equipment specifications for performing dedicated narrow area communication, and introduction is easy.

  In addition, it is preferable to use an ETC (Electronic Toll Collection) device installed for toll collection on highways, toll roads, etc., as infrastructure equipment for performing dedicated narrow area communication. This is because the radio waves transmitted from the ETC device can be received by a simple receiver, and the altitude information in the map data for the navigation device is beginning to be provided mainly in highways and toll roads in urban areas. is there.

  In the altitude calculation apparatus according to the second aspect of the present invention, when the altitude correction means corrects the altitude, the altitude calculation means calculates the altitude relative to the reference value using the corrected altitude as a reference value. It is characterized by.

  In the second invention, when the altitude is corrected, the altitude corrected for the subsequent altitude calculation processing is set as a reference value, and the altitude is calculated from the reference value. All the included errors are canceled, and the error accumulated before the correction is not affected by the altitude calculation process after the correction, and the accuracy of the altitude calculated after the correction can be improved. Regarding the correction of altitude, it is preferable to correct the calculated altitude so as to replace it with the absolute altitude specified from the map data because the accuracy of the altitude calculation process thereafter is improved.

  Further, in the altitude calculation apparatus according to the third aspect of the present invention, when the altitude correction means performs a plurality of corrections, the movement distance calculation means calculates an inter-correction movement distance between the corrected locations. An altitude difference calculating means for calculating an altitude difference calculated by the altitude calculating means with respect to the corrected altitude and the corrected location, and an altitude difference calculated by the altitude difference calculating means and the movement distance between corrections. An error calculating means for calculating an error for a predetermined distance based on the error, and an altitude correcting means for correcting the altitude calculated by the altitude calculating means after the altitude correcting means corrects based on the error calculated by the error calculating means. It is characterized by providing.

  In the third invention, when the correction is performed a plurality of times, the altitude calculated for the location where the current correction is performed within the section (movement distance) from the location where the previous correction was performed to the location where the current correction was performed Since the error included in is calculated, the ratio of the error to the predetermined movement distance can be obtained, and the tendency of the error with respect to the altitude calculation can be grasped. Furthermore, by correcting the calculated altitude using the error tendency, it is possible to reduce the influence of the error associated with the altitude calculation and to realize highly accurate altitude calculation.

  A navigation apparatus according to a fourth aspect of the present invention is a map for performing a map matching process for matching a position calculated based on position information received by the position information receiving means and position information received by the position information receiving means to a road on the map. In a navigation device comprising matching means, whether or not to perform map matching processing based on any of the height calculation devices and the height calculated by the height calculation means of the height calculation device or the height corrected by the height correction means And determining means for determining whether or not.

  In the fourth aspect of the invention, the map matching process is determined using the highly reliable altitude calculated by the altitude calculating apparatus or the corrected absolute altitude. Can be judged. For example, when a vehicle is located on the upper floor in a multi-story parking lot adjacent to a road, the altitude calculation device calculates the altitude corresponding to the upper floor of the multi-story parking lot. Therefore, it is possible to determine that the vehicle position is not map-matched on the road, and it is possible to improve the reliability of the map matching process.

  A navigation device according to a fifth aspect of the present invention is a map for performing a map matching process for matching a position calculated based on position information received by the position information receiving means and position information received by the position information receiving means to a road on the map. In a navigation device comprising a matching means, when the map matching means performs a map matching process in a location where a plurality of roads having a difference in height are close to any one of the height calculation devices, the height of the height calculation device Means for identifying a map matching destination road based on the altitude calculated by the calculating means or the altitude corrected by the altitude correcting means.

  In the fifth aspect of the invention, the map matching destination road is identified using the highly reliable altitude calculated by the altitude calculating device or the corrected absolute altitude, so that the map matching process can be performed with higher accuracy than before. Yes. In other words, when map matching processing is performed in a location where multiple roads with different altitudes are close to each other, it is possible to better identify which road to perform map matching based on the altitude obtained from the altitude calculation device. Accurate map matching processing can be realized when the road and the road on the surface are parallel. For a plurality of roads that are subject to map matching, it is preferable to use altitude information that is attached to toll roads, expressways, etc. of the map data, and the road type included in the map data It is preferable to grasp the road type of the map matching destination using this information.

In the first invention, it is possible to acquire the absolute altitude from the map database by using the information transmitted by the dedicated narrow area communication, and calculate based on the acquired absolute altitude. Altitude can be corrected accurately.
In the second invention, when the altitude is corrected, the altitude corrected for the subsequent altitude calculation processing is used as a reference value, and the altitude is calculated from the reference value. It can be improved.

  In the third invention, when the correction is performed a plurality of times, an error in the altitude calculated for the current correction location in the distance of the corrected section can be obtained, so the error in the calculated altitude for the predetermined moving distance A tendency can be grasped, and further, a high-precision altitude can be obtained by making corrections by using the error tendency obtained by grasping the calculated altitude.

In the fourth aspect of the invention, the map matching process is determined using the highly reliable altitude calculated by the altitude calculating apparatus or the corrected absolute altitude. Can be judged.
In the fifth aspect of the invention, the map matching destination road is identified using the highly reliable altitude calculated by the altitude calculating device or the corrected absolute altitude, so that the map matching process can be performed with higher accuracy than before. Yes.

  FIG. 1 is a block diagram showing a main configuration of a navigation device 1 according to an embodiment of the present invention. The navigation device 1 of this embodiment is an in-vehicle device having an altitude calculation function, and the absolute altitude at the position where the toll gate 30 having the ETC device 31 is provided as shown in FIG. Is included in advance in the map database 20 included in the information, and the absolute height of the current location is acquired from the map database 20 with the reception of information transmitted from the ETC device, and is calculated based on the acquired absolute height. It is characterized by calibrating (correcting) the altitude.

  The navigation device 1 includes various receivers 2, 3, 3D gyro sensor 4, vehicle-side connector 5, position detection processing unit 6, guidance processing unit 7, route calculation processing unit 8, user interface unit 9, display unit 10, and A storage unit 11 is provided to detect the current position by receiving radio waves emitted from an artificial satellite using GPS (Global Positioning System), and calculate the current position based on the detected position and the detection result of the sensor. Perform guidance to the destination.

  The storage unit 11 uses a hard disk device in the present embodiment, and stores the map database 20 in the hard disk device. In the map database 20, in addition to map data for displaying the map 40 as shown in FIG. 3A on the display unit 10, links representing roads included in the map 40 and nodes representing intersections of the roads are displayed. Data of such two-dimensional position information is included. Further, the map database 20 of the present embodiment includes a two-dimensional place (latitude and longitude) of a toll gate (see FIG. 2) having an ETC device 31 indicated by the icons 42a and 42b on the toll road 41 on the map 40, and It also includes a table with high values.

  FIG. 3B shows a toll booth position table 46 having positions and altitude values of the toll booths A, B, C, etc. included in the map database 20. The toll booth position table 46 associates altitudes (absolute altitudes) with places (latitudes and longitudes) such as the toll booths A, B, C, etc. , Values measured strictly for C, etc. are used.

  The GPS receiver 2 of the navigation device 1 shown in FIG. 1 corresponds to position information receiving means for receiving GPS radio waves, and is connected to the map matching process 6c in the position detection processing unit 6 so that the received radio waves are received. The included position information (latitude / longitude data) is transmitted to the map matching processing unit 6c.

  The ETC signal receiver 3 receives information (ETC signal) transmitted from the transmission antenna 31 of the ETC device 31 of FIG. Note that the ETC signal receiver 3 of the present embodiment does not need to have a protocol corresponding to information transmission / reception related to toll collection on a general toll road (although of course may be provided), and is simply a transmission antenna 31. It is structured to be able to receive information transmitted from. Similarly to the GPS receiver 2, the ETC signal receiver 3 is also connected to the map matching process 6c in the position detection processing unit 6. When information is received from the ETC device 31, the fact that it has been received is indicated by a map matching process. The process which notifies to the part 6c is performed.

  The 3D gyro sensor 4 detects the posture and running state of the vehicle, and is configured by combining the acceleration sensor 4a and the vibration gyro 4b, and is connected to the sensor data processing unit 6a in the position detection processing unit 6. Then, the detected content is transmitted to the sensor data processing unit 6a.

  The vehicle-side connector 5 is connected to a signal extraction connector (not shown) provided in the vehicle. The signal extraction connector provided in the vehicle is connected to a sensor that detects the rotation state of the axle provided in the vehicle, so that the vehicle speed pulse signal output from the sensor can be extracted, and further, the transmission of the vehicle It is also connected to a sensor that detects that the gear selector is in the reverse state, and the reverse signal output from this sensor can also be taken out. The vehicle-side connector 5 is connected to a vehicle signal extraction connector, and is wired so that the vehicle speed pulse signal and the reverse signal extracted from the signal extraction connector can be transmitted to the sensor data processing unit 6a.

  The position detection processing unit 6 of the navigation device 1 performs processing for calculating the current position (vehicle position) at a required time interval (for example, every 3 seconds). The sensor data processing unit 6a, the own vehicle A position calculation unit 6b and a map matching processing unit 6c are provided.

  The sensor data processing unit 6a calculates the left and right turning angles of the vehicle based on the content sent from the 3D gyro sensor 4, and as shown in FIG. 4, the inclination of the vehicle traveling direction (moving direction) with respect to the horizontal line G A process for calculating the angle θ is performed. In addition, the sensor data processing unit 6 a performs a process of calculating the moving distance L of the vehicle S according to the number of vehicle speed pulse signals sent from the vehicle side connector 5. The sensor data processing unit 6a also determines that the vehicle is moving backward based on the reverse signal sent from the vehicle side connector 5.

  The own vehicle position calculation unit 6b calculates the position of the vehicle S by self-contained navigation. The sensor data processing unit 6a is two-dimensional based on the detection content from the 3D gyro sensor 4 and the value obtained from the vehicle speed pulse signal. The present position is obtained, and in this embodiment, the altitude of the place where the vehicle S is located is also calculated from the inclination angle and the movement distance obtained by the sensor data processing unit 6a. For example, when the vehicle S moves to a position P as shown in FIG. 4, the vehicle position calculation unit 6 b converts the movement distance L to a trigonometric function (sin θ, tan θ depending on the values of sin θ and θ) of the inclination angle θ. To obtain the altitude h of the position P with respect to the horizontal line G.

  The altitude h obtained by the vehicle position calculation unit 6b is the detection error in the 3D gyro sensor 4, the error included in the vehicle speed pulse signal, the number of digits in the calculation in the sensor data processing unit 6a and the vehicle position calculation unit 6b. Errors due to truncation, etc. are accumulated and do not match the absolute altitude, and the value includes accumulated errors.

  Further, when the absolute altitude is transmitted from the map matching processing unit 6c as described later, the own vehicle position calculating unit 6b calibrates (corrects) the altitude calculated based on the absolute altitude. I do. As a specific correction process, the calculated altitude is replaced with an absolute altitude, and after correcting for the absolute altitude, the absolute altitude is used as a reference value, and the altitude relative to that reference value is set. (Hereinafter referred to as altitude difference) is calculated, and the value obtained by adding the calculated altitude difference to the reference value is used as the altitude at that location. In this way, by calculating the altitude difference with respect to the reference value after correction, the accumulated error is included only in the value calculated as the altitude difference. High altitude.

  Further, the map matching processing unit 6c is based on the latitude / longitude data (position information) transmitted from the GPS receiver 2 and the position obtained by the self-contained navigation in the vehicle position calculation unit 6b. A process for calculating the position (latitude and longitude) is performed, and a map matching process for matching the calculated two-dimensional vehicle position with a road on the map included in the map database is performed.

  Furthermore, when the map matching processing unit 6c according to the present embodiment receives the ETC signal from the ETC signal receiver 3, the map matching unit 6c determines the nearest toll gate in the vicinity of the calculated two-dimensional vehicle position from the map database 20. Perform search processing. The specific processing content of the search includes the latitude and longitude of the toll gate within a range in which the ETC signal can be received around the latitude and longitude of the vehicle position calculated by the map matching processing unit 6c when the ETC signal is received. If the toll gate is included in the range, the map matching processing unit 6c specifies the absolute altitude of the toll gate from the toll gate location table 46 shown in FIG. To get an advanced altitude.

  Further, the map matching processing unit 6c performs a process of sending the acquired absolute altitude to the own vehicle position calculation unit 6b, and accordingly, the own vehicle position calculation unit 6b performs a correction process of the calculated altitude. When the map matching processing unit 6c searches the map database 20 for the latest toll gate, there is no corresponding toll gate within the distance range in which information transmitted from the transmitting antenna 31a of the ETC device 31 in FIG. 2 can be received. When it is determined that the ETC signal is not received in a normal state, the process for obtaining the absolute altitude is not performed.

  On the other hand, the guidance processing unit 7 in the navigation apparatus 1 of FIG. 1 performs processing related to guidance from the vehicle position obtained by the position detection processing unit 6 to the destination set by the user using the map database 20. It is. Further, the route calculation processing unit 8 calculates a route to the destination using the processing contents performed by the guidance processing unit 7 and the map database 20. Furthermore, the user interface unit 9 accepts user operations for destination setting, menu selection, and the like, and the display unit 10 displays the map 40 shown in FIG. 3A to the calculated vehicle position and destination. And a menu etc. are displayed as appropriate according to the user's operation.

  In the navigation device 1 of FIG. 1, a portion excluding the guidance processing unit 7 and the route calculation processing unit 8 (ETC signal receiver, 3D gyro sensor 4, vehicle side connection connector 5, position detection processing unit 6 and the like) This is related to the process of calculating the altitude of the position of the vehicle S, and the part related to the process of calculating the altitude corresponds to the altitude calculation apparatus. Therefore, the navigation device 1 has a form in which an altitude calculation device is incorporated. It is also possible to combine the parts related to the altitude calculation device into the form of a component unit for the navigation device.

  FIG. 5 is a flowchart showing a series of processing procedures related to altitude correction by the navigation device 1 having the above-described configuration. Hereinafter, the flow of processing relating to altitude correction of the navigation device 1 of the present embodiment will be described according to this flowchart.

  First, the part corresponding to the altitude calculation device of the navigation device 1 determines whether or not an ETC signal has been received (S1). finish. If an ETC signal is received (S1: YES), it is determined by searching the map database 20 whether there is a toll gate in the vicinity of the received position (S2). When there is no toll gate in the vicinity range (S2: NO), the process related to altitude correction is terminated.

  If there is a toll gate in the vicinity range (S2: YES), the toll gate in the vicinity (nearest) is specified (S3), the absolute altitude is acquired from the map database 20 (S4), and acquired. Based on the absolute altitude, the altitude calculated by the vehicle position calculation unit 6b is corrected (S5).

  Therefore, when the vehicle S equipped with the navigation device 1 that performs the above-described process travels on the elevated toll road 25 as shown in FIG. 6, the first toll gate 30 is reached and the ETC signal is transmitted from the transmission antenna 31a. Is received, the altitude h1 calculated at the time of reaching the toll gate 30 is corrected to be replaced with the absolute altitude H1 acquired from the map database 20, so that the navigation device 1 can easily obtain an accurate altitude (absolute altitude H1). .

  Further, when passing through the toll gate 30, the absolute altitude H1 is set as a reference value, and the own vehicle position calculation unit 6b of the navigation device 1 calculates the altitude difference Δh from the reference value. Therefore, the altitude at the position of the vehicle S after passing through the toll gate 30 is Δh + H1, and since the accumulation error relating to detection and calculation is included only in the altitude difference Δh, the error content rate in the altitude (Δh + H1) of the vehicle position The altitude (Δh + H1) calculated in total once corrected is a value that is more accurate than in the past.

  Further, when the vehicle S arrives at the second toll booth 32, the navigation apparatus 1 obtains the absolute altitude H2 of the toll booth 32 with the reception of the ETC signal transmitted from the transmission antenna 33a, and has calculated it so far. Correction that replaces altitude (Δh + H1) with absolute altitude H2 is performed, and accumulated errors are wiped out (reset). Thereafter, when passing through the second toll gate 32, similarly to the above, using the absolute altitude H2 as a reference value, an altitude difference Δh that is different from the reference value is calculated, and the altitude of the vehicle position is obtained as Δh + H2. . As a result, the navigation device 1 mounted on the vehicle S acquires the absolute altitude every time it passes through the toll booth where the ETC device is installed, resets the accumulated error, and starts to calculate again after resetting. The degree of error is reduced compared to the conventional case, and high-precision altitude calculation is realized.

  In addition, the altitude calculation part of the navigation device 1 of the present embodiment is not limited to the above-described form, and various modifications can be applied. For example, as shown in FIG. 6, when the correction is made a plurality of times after passing through the toll gates 30 and 32, first, the travel distance from the first toll gate 30 to the second toll gate 32 (moving distance between corrections). Is calculated based on the vehicle speed pulse signal and the difference between the absolute altitude H2 acquired at the second toll gate 32 and the altitude (Δh + H1) calculated when the second toll gate 32 is reached (H2− ( Δh + H1)) may be calculated by the own vehicle position calculation unit 6b, and the calculated ratio of the difference to the movement distance between corrections may be calculated as an error related to the altitude calculation of the navigation device 1.

  The error calculated in this way can be used to determine an error tendency with respect to the moving distance that occurs when the altitude of the navigation device 1 is calculated. Further, after calculating this error, an index for canceling the error according to the moving distance is obtained at any time by the own vehicle position calculation unit 6b, and the altitude calculated by the navigation device 1 is corrected using this index, The altitude accuracy calculated by the navigation device 1 after passing through the toll gate can be improved.

  Furthermore, in the above description, the absolute altitude is acquired at a toll booth equipped with an ETC device. However, if an infrastructure is established in the future where information can be transmitted to the vehicle by DSRC at a location other than the toll booth. , Measure the absolute altitude of the location where the information is transmitted by DSRC, create a map database including the measured altitude in association with the measured location (latitude and longitude), and use this map database for the navigation device 1 You may memorize | store in the memory | storage part 11. FIG. In this way, altitude correction processing can be performed at a location where information is transmitted by DSRC other than the toll gate, and altitude accuracy obtained by the navigation device 1 can be further increased.

  Further, by assigning altitude information (value) to various roads included in the map database, the altitude obtained by the navigation device 1 by calculation (including correction) or correction is appropriately used for map matching processing. Also good. For example, when the altitude is given to the road 51 on the map 50 shown in FIG. 7A, the area R representing the two-dimensional vehicle calculated by the navigation device 1 is the area facing the road 51. 52.

  In this case, if the map matching process is performed, the position R indicating the vehicle is matched with the road 51. However, when the map matching process is performed, the altitude obtained by the navigation device 1 at the position R and the map matching are obtained. The altitude of the road 51 ahead is compared by the position detection processing unit 6 of the navigation device 1, and if both altitudes exceed a predetermined value (for example, 3m or 5m), the map matching process is performed. The calculated position R is allowed to remain in the area 52. By performing such processing, for example, when the vehicle is located on the floor above the first floor in the multilevel parking lot facing the road, erroneous map matching processing can be prevented, and the display reflecting the actual vehicle position A form can be secured.

  Furthermore, even when the map matching process is performed in a place where the elevated road 56 and the road 57 under the elevated road in the map 55 shown in FIG. 7B are parallel (adjacent), at least one of the roads 56 and 57 is used. When the altitude information (value) is assigned to the map, the altitude obtained by the navigation device 1 by calculation (including correction) or correction can be used to specify the map matching destination.

  Specifically, if the altitude is given to both the roads 56 and 57, the altitude obtained by the navigation device 1 is compared with the altitude of each road 56 and 57 by the position detection processing unit 6 of the navigation device 1. One with a smaller difference can be specified as a map matching destination. Also, if the altitude is given to only one of the roads 56 and 57, the road to which the altitude is given can be used as the map matching destination if the altitude and the altitude obtained by the navigation device 1 are equal. If the altitudes are not equal, the road to which the altitude is not given can be specified as the map matching destination, which can contribute to the improvement of map matching accuracy.

1 is a block diagram of a navigation device according to an embodiment of the present invention. It is a perspective view which shows the state through which the vehicle carrying the navigation apparatus of this embodiment passes the toll gate provided with the ETC apparatus. (A) is the schematic which shows an example of the map contained in a map database, (b) is a chart which shows the toll gate position table containing the altitude of a toll gate. It is the schematic which shows the inclination | tilt angle with respect to the moving vehicle, a moving distance, etc. FIG. It is a flowchart which shows a series of processing procedures concerning correction | amendment of the calculated altitude. It is the schematic which shows the altitude which the navigation apparatus obtained when a vehicle passes an elevated toll road obtains. (A) is the schematic of the map showing an example which does not perform a map matching process, (b) is the schematic of the map showing an example which specifies a map matching destination from several adjacent roads.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 2 GPS receiver 3 ETC signal receiver 4 3D gyro sensor 4a Acceleration sensor 4b Vibration gyro 5 Vehicle side connector 6 Position detection process part 6a Sensor data process part 6b Own vehicle position calculation part 6c Map matching process part 20 Map Database 30, 32 Tollgate 31 ETC device 31a, 33a Transmitting antenna 40, 50, 55 Map 41, 51, 56, 57 Road S Vehicle θ Inclination angle

Claims (5)

Based on the movement distance calculation means for calculating the movement distance, the inclination angle detection means for detecting the inclination angle with respect to the horizontal line in the movement direction, the movement distance calculated by the movement distance calculation means and the inclination angle detected by the inclination angle detection means. In an altitude calculation device comprising an altitude calculation means for calculating an altitude,
A map database having an altitude of the location in association with a location where information transmitted by dedicated narrow area communication can be received;
Receiving means for receiving information through dedicated narrowband communication;
When the receiving means receives information, the specifying means for specifying the altitude of the received location from the map database;
An altitude calculating device comprising: an altitude correcting unit that corrects the altitude calculated by the altitude calculating unit based on the altitude specified by the specifying unit.   2. The altitude calculation device according to claim 1, wherein when the altitude correction means corrects the altitude, the altitude calculation means calculates the altitude relative to the reference value using the corrected altitude as a reference value. When the altitude correction means performs a plurality of corrections, the movement distance calculation means calculates the movement distance between corrections between the places where the correction has been performed,
An altitude difference calculating means for calculating a difference in altitude calculated by the altitude calculating means for the corrected altitude and the corrected location;
Error calculating means for calculating an error with respect to a predetermined distance based on the difference in altitude calculated by the altitude difference calculating means and the movement distance between corrections;
The altitude correction unit according to claim 1, further comprising: an altitude correcting unit that corrects the altitude calculated by the altitude calculating unit after the altitude correcting unit corrects based on the error calculated by the error calculating unit. Calculation device. In a navigation apparatus comprising position information receiving means for receiving position information, and map matching means for performing map matching processing for matching a position calculated based on the position information received by the position information receiving means with a road on the map,
The altitude calculation device according to any one of claims 1 to 3,
A navigation device comprising: a determination unit that determines whether or not to perform map matching processing based on an altitude calculated by the altitude calculation unit of the altitude calculation device or an altitude corrected by the altitude correction unit. In a navigation apparatus comprising position information receiving means for receiving position information, and map matching means for performing map matching processing for matching a position calculated based on the position information received by the position information receiving means with a road on the map,
The altitude calculation device according to any one of claims 1 to 3,
When the map matching unit performs map matching processing in a location where a plurality of roads having different altitudes are close to each other, based on the altitude calculated by the altitude calculating unit of the altitude calculating device or the altitude corrected by the altitude correcting unit. A navigation apparatus comprising: means for specifying a map matching destination road.

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