JP2004309152A - Vehicle-mounted navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle-mounted navigation system capable of modifying map data in accordance with the shape of an actual road in the case that the shape of the actual road is substantially different from the shape of the road by the map data. <P>SOLUTION: A control part 18 stores in a HDD 11 sections in which mismatches have occurred. It is determined that the shapes of roads by the map data are substantially different from the shapes of actual roads in sections in which a previously set number of mismatches or more have occurred, and the map data on the sections stored in the HDD 11 is modified along a travel track of a vehicle. Since the shapes of the roads displayed on a display device 7 are thereby brought close to the shapes of the actual roads, it is possible to display marks for vehicle locations on correct roads. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an in-vehicle navigation device having a function of correcting a current position of a vehicle detected by a vehicle position detection device to a position on a road by map matching.
[0002]
[Prior art]
The in-vehicle navigation device includes a map storage device such as a DVD (Digital Versatile Disk) or an HDD (Hard Disk Drive) on which map data is recorded, a display device such as a liquid crystal panel, a gyro, a GPS (Global Positioning System) receiver, and the like. It has a vehicle position detecting device for detecting the current position and current direction of the vehicle, such as a vehicle speed sensor. Then, the map data including the current position of the vehicle is read from the map storage device, a map image around the current position of the vehicle is drawn based on the map data and displayed on the display device, and the vehicle position mark (location) is displayed. It is displayed over the map image, and the map image is scrolled according to the movement of the vehicle, or the map image is fixed on the screen and the vehicle position mark is moved to determine where the vehicle is currently traveling. It is easy to understand at a glance.
[0003]
In addition, usually, the in-vehicle navigation device is equipped with a route guidance function that enables a user to easily travel to a desired destination without making a mistake on a road. According to this route guidance function, the lowest cost route from the starting point to the destination is automatically searched by performing a simulation calculation such as the horizontal search method or the Dijkstra method using the map data, and the searched route is guided. It is stored as a route, and during driving, the guidance route is displayed in a different color from other roads and is drawn thick, and within a certain distance from the intersection where the vehicle should change the route on the guidance route When approaching, the user is guided to the destination by drawing an arrow indicating the course at the intersection where the course should be changed on the map and displaying the arrow on the screen.
[0004]
The cost is a value obtained by multiplying a constant based on a road width, a road type (such as a general road or an expressway), a right turn, a left turn, and the like based on the distance, a predicted traveling time of a vehicle, and the like. Is a numerical value of the degree of appropriateness. Even if there are two routes having the same distance, the cost differs depending on whether the user specifies, for example, whether to use a toll road, or gives priority to distance or time.
[0005]
By the way, the vehicle position detected by the vehicle position detecting device includes an unavoidable error. Therefore, when the vehicle position mark detected on the map image is displayed on the map image with the vehicle position detected by the vehicle position detection device as it is, the vehicle position mark is located at a position off the road even though the vehicle is traveling on the road. May be displayed. In order to avoid such inconveniences, an ordinary in-vehicle navigation device uses a technique called map matching as described in, for example, Japanese Patent Application Laid-Open No. 5-60566.
[0006]
In the map matching, the current position of the vehicle detected by the vehicle position detection device is compared with map data and corrected to a position on the road in the map image. This prevents the vehicle position mark from being displayed at a position off the road. However, since the vehicle may travel on a place other than the road, the position of the vehicle and the position of the road detected by the vehicle position detection device are greatly separated, or the direction of the road and the traveling direction of the vehicle are significantly different. In this case, the vehicle position mark is displayed at the current position of the vehicle detected by the vehicle position detection device without matching the vehicle position on the road.
[0007]
[Patent Document 1]
JP-A-5-60566 [Patent Document 2]
JP-A-2002-54938
[Problems to be solved by the invention]
In some cases, the actual road shape does not match the road shape drawn by the map data. In this case, if the difference between the actual road shape and the road shape based on the map data is large, a vehicle position mark is displayed at a position away from the road on the map image even though the vehicle is traveling on the road. Or a vehicle position mark may be displayed on another road. Such a state in which a mistake has occurred in the map matching processing is called mismatching.
[0009]
In Japanese Patent Application Laid-Open No. 2002-54938, since the actual road shape and the road shape based on the map data are largely different in mountainous regions, for example, a database of mountainous regions is prepared, and vehicles are used in mountainous regions. It describes that when it is determined that the vehicle is traveling on a road, the vehicle position is forcibly matched with the road on the map image. This publication also discloses that a change in height may be detected to determine whether or not the area is a mountain area.
[0010]
However, there is a road other than a mountainous area where the actual road shape does not match the road shape based on the map data. Therefore, regardless of whether it is a mountain area or not, a road whose actual road shape does not match the road shape based on the map data is automatically detected, and either the map data or the display position of the vehicle position mark is detected. It is desired to correct.
[0011]
In view of the above, an object of the present invention is to provide an in-vehicle navigation device that corrects map data according to an actual road shape when the actual road shape greatly differs from the road shape based on the map data.
[0012]
Another object of the present invention is to provide an in-vehicle navigation device that can display a vehicle position mark on a road in a map image even when the actual road shape and the road shape based on the map data are significantly different. is there.
[0013]
[Means for Solving the Problems]
The above-mentioned problems include a map storage unit that stores map data, a vehicle position detection unit that detects a current position of a vehicle, a display device that can display a map image, and a data storage unit that can read and write data. And map data drawing means for drawing a map image to be displayed on the display device based on the map data, and a map matching process using the map data for a current position of the vehicle detected by the vehicle position detection means, A control unit that determines a display position of a vehicle position mark to be displayed on the map image, wherein the control unit determines a section in which the mismatch occurred when the mismatch occurred in the map matching process. In a section in which mismatching has occurred more than a preset number of times, the map data of the section is stored in the traveling locus of the vehicle. To change it solved by the in-vehicle navigation device according to claim.
[0014]
In addition, the above-described problems include a map storage unit that stores map data, a vehicle position detection unit that detects a current position of a vehicle, a display device that can display a map image, and a data device that can read and write data. Storage means, map data drawing means for drawing a map image to be displayed on the display device based on the map data, and map matching processing of the current position of the vehicle detected by the vehicle position detection means using the map data. A control unit that determines a display position of a vehicle position mark to be displayed on the map image, wherein the control unit determines a section where the mismatch has occurred when the mismatch occurs in the map matching process. The vehicle position mark is stored in the map data in the section where the mismatch has occurred more than a preset number of times stored in the data storage means. Forcibly be displayed on the road drawn solved by vehicle navigation apparatus according to claim Ri.
[0015]
In the present invention, the section where the mismatch has occurred is stored in the data storage means. Then, in a section where mismatching occurs more than a preset number of times, it is determined that the difference between the road shape based on the map data and the actual road shape is large, and the map data of the section is determined along the traveling locus of the vehicle. Change. Thus, the road shape displayed on the display device becomes closer to the actual road shape, and the vehicle position mark can be displayed on the correct road.
[0016]
Further, instead of changing the road data, a vehicle position mark may be compulsorily displayed on the road. In this case, the display position of the vehicle position mark is determined at any time from, for example, the map data and the travel distance of the vehicle as the vehicle moves. Even in this case, the vehicle position mark can be displayed on a correct road.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0018]
(First Embodiment)
FIG. 1 is a block diagram showing a configuration of a vehicle-mounted navigation device according to a first embodiment of the present invention.
[0019]
Reference numeral 3 denotes an operation unit provided with various operation buttons and the like for operating a navigation device body 10 described later. 5 receives a GPS signal transmitted from a GPS satellite and detects the longitude and latitude of the current position of the vehicle. GPS receiver.
[0020]
Reference numeral 6 denotes a self-contained navigation sensor. The self-contained navigation sensor 6 includes an angle sensor 6a such as a gyro that detects a vehicle rotation angle, and a traveling distance sensor 6b that generates a pulse at every constant traveling distance. Reference numeral 7 denotes a display device such as a liquid crystal panel. The navigation device main body 10 displays a map around the current position of the vehicle on the display device 7, and provides guidance routes from the departure point to the destination, vehicle position marks, and the like. Display guidance information. Reference numeral 9 denotes a speaker for providing guidance information to the user by voice.
[0021]
The navigation device main body 10 includes the following. Reference numeral 11 denotes an HDD from which data can be read and written. As shown in FIG. 2, the HDD 11 is provided with a map storage area for storing map data and a data storage area for storing data other than the map data.
[0022]
In the map data stored in the HDD 11, roads and the like are stored as a coordinate set of vertices (nodes) represented by longitude and latitude. A road is formed by connecting two or more nodes, and a portion connecting the two nodes is called a link. The map data includes (1) a road layer including a road list, a node table, an intersection configuration node list, and the like; (2) a background layer for displaying roads, buildings, parks, rivers, and the like on a map screen; 3) It is composed of a character / symbol layer for displaying characters such as names of administrative divisions such as municipalities, names of roads, names of intersections, names of buildings, and map symbols.
[0023]
Reference numeral 13 denotes an interface connected to the operation unit 3, reference numeral 15 denotes an interface connected to the GPS receiver 5, and reference numeral 16 denotes an interface connected to the self-contained navigation sensor 6.
[0024]
Reference numeral 17 denotes a buffer memory for temporarily storing map data read from the HDD 11, and reference numeral 18 denotes a control unit constituted by a microcomputer. The control unit 18 detects the current position of the vehicle based on signals input from the interfaces 15 and 16, reads map data of a predetermined area from the HDD 11 to the buffer memory 17, and reads map data read to the buffer memory 17. Various processes are executed, such as searching for a guidance route from the departure place to the destination under the search conditions set by using.
[0025]
Reference numeral 19 denotes a map drawing unit which draws a map image using the map data read into the buffer memory 17, and 21 draws various menu screens (operation screens) and various marks such as a vehicle position mark and a cursor according to the operation status. It is an operation screen / mark drawing unit to be operated.
[0026]
Reference numeral 22 denotes a guidance route storage unit that stores the guidance route searched by the control unit 18, and reference numeral 23 denotes a guidance route drawing unit that draws the guidance route. The guidance route storage unit 22 stores all nodes of the guidance route searched by the control unit 18 from the departure place to the destination. The guide route drawing unit 23 reads the guide route information (node sequence) from the guide route storage unit 22 and draws the guide route information (node row) in a color and thickness different from those of other roads.
[0027]
An audio output unit 24 supplies an audio signal to the speaker 9 based on a signal from the control unit 18. Reference numeral 25 denotes an image synthesizing unit, which superimposes a map image drawn by the map drawing unit 19, various marks drawn by the operation screen / mark drawing unit 21, an operation screen, a route drawn by the route drawing unit 23, and the like. Output to the device 7.
[0028]
In the on-vehicle navigation device thus configured, the control unit 18 detects the current position of the vehicle from the GPS signal received by the GPS receiver 5 and the signal input from the self-contained navigation sensor 6. Then, map data around the current position of the vehicle is read from the HDD 11 and stored in the buffer memory 17. The map drawing unit 19 generates a map image based on the map data read into the buffer memory 17, and displays a map image around the current position of the vehicle on the display device 7.
[0029]
The control unit 18 detects the current position of the vehicle based on signals input from the GPS receiver 5 and the self-contained navigation sensor 6 with the movement of the vehicle, performs a map matching process on the detection result, and displays the position of the vehicle position mark. To determine. Then, the vehicle position mark is superimposed on the map image displayed on the display device 7, and the vehicle position mark is moved as the vehicle moves, or the map image is scroll-displayed.
[0030]
Further, when the user operates the operation unit 3 to set a destination, the control unit 18 sets the current position of the vehicle as a departure point, and uses a map data to provide a guidance route from the departure point to the destination under preset conditions. Then, the guidance route obtained by the search is stored in the guidance route storage unit 22. Then, the control unit 18 outputs guidance information as needed as the vehicle travels, and guides the vehicle to travel along the guidance route to the destination.
[0031]
Further, the control unit 18 stores in the data storage area of the HDD 11 a section in which a mismatch has occurred in the map matching process (hereinafter, referred to as a mismatch section) and a running locus of the vehicle at that time, and stores a plurality of sections in the same section. When the time mismatch occurs, the data of the road in the map data stored in the HDD 11 is changed based on the data of the traveling locus.
[0032]
Hereinafter, an operation of the in-vehicle navigation device according to the present embodiment when a mismatch section is detected will be described with reference to an example of a map image shown in FIG. In FIG. 3, reference numeral 31 denotes a road (road shape) drawn by map data, and a broken line 32 denotes an actual shape of the road. When a vehicle travels on this road, mismatching is likely to occur at places where there is a large difference between the actual road shape and the road shape drawn by the map data (places surrounded by a chain line in FIG. 3).
[0033]
Two cases can be considered for mismatching. The first case is when there is no corresponding road near the vehicle position detected by the GPS receiver 5 and the self-contained navigation sensor 6, and the second case is to match the vehicle position to a road different from the traveling road. It is when. In either case, when a mismatch occurs, the vehicle position mark jumps from the traveling road to another location, so that the control unit 18 can detect the occurrence of the mismatch. Similarly, when returning from the mismatching, the vehicle position mark jumps and returns to the original road, so that the control unit 18 can detect the elimination of the mismatching.
[0034]
The control unit 18 records the vehicle position detected by the GPS receiver 5 and the self-contained navigation sensor 6 in the data storage area of the HDD 11 as the mismatched section travel trajectory data from the occurrence of the mismatch until the cancellation.
[0035]
FIG. 4 is a flowchart illustrating a process of detecting a mismatch section.
[0036]
First, in step S11, the control unit 18 detects the current position of the vehicle based on signals from the GPS receiver 5 and the self-contained navigation sensor 6. Then, the process shifts to step S12 to execute a map matching process using the map data read into the buffer memory 17. Thereafter, in step S13, it is determined whether or not mismatching has occurred. It is assumed that there is no mismatch at first, and the current position of the vehicle is matched on the road on which the vehicle is traveling. If the vehicle is traveling on a road where the difference between the actual shape and the shape based on the map data is small, the processing from step S11 to step S13 is repeated.
[0037]
When the vehicle arrives at a point where the actual road shape and the road shape based on the map data are significantly different and mismatching occurs, the process proceeds from step S13 to step S14. In step S14, the current position of the vehicle detected by the GPS receiver 5 and the self-contained navigation sensor 6 is stored in the HDD 11 as the starting point of the mismatch. In addition, the control unit 18 starts recording the traveling locus data of the mismatched section, that is, the vehicle position detected by the outputs of the GPS receiver 5 and the self-contained navigation sensor 6. These data are stored in the data storage area of the HDD 11.
[0038]
Next, the process proceeds to step S15, where the current position of the vehicle is detected again based on signals from the GPS receiver and the self-contained navigation sensor. Then, the process proceeds to step S16 to execute a map matching process.
[0039]
Next, the process proceeds to step S17, and it is determined whether or not the vehicle position is matched on the road. If the vehicle cannot be matched on the road, the process returns to step S15, and after a predetermined time has elapsed, the current position of the vehicle is detected again.
[0040]
On the other hand, when the vehicle position is matched on the road in step S17, the process proceeds to step S18, and it is determined whether the matched road is the original road. If it is not the original road, the process returns to step S15, and the detection of the vehicle position (step S15) and the matching process (step S16) are repeated until the vehicle is matched with the original road. However, if the vehicle position cannot be matched with the original road even if a certain time has elapsed since the occurrence of the mismatch, or if the vehicle cannot be matched with the original road even after traveling a certain distance, Assuming that the vehicle is traveling on a road different from the above, the mismatch section detection processing is stopped.
[0041]
If it is determined in step S18 that the original road has been matched, the process proceeds to step S19. In step S19, the current position of the vehicle is recorded in the HDD 11 as the end point of the mismatch section. Then, the recording of the running locus of the mismatch section ends. In this manner, the data of the start position and the end position of the mismatch section and the traveling locus of the vehicle in the mismatch section are recorded in the HDD 11. Thereafter, a process of determining whether or not to change the map data is performed.
[0042]
FIG. 5 is a flowchart showing a process for determining whether or not to change map data. First, in step S21, it is determined whether or not the number of mismatch occurrences in the section where the mismatch has occurred is equal to or less than a preset number (for example, three or less, or the map matching rate is 20% or less). If the number of mismatches is equal to or greater than the preset number, the process proceeds to step S22, and the map data of the section is changed along the traveling locus of the vehicle. For example, the travel locus may be used as it is as the data used for drawing the road, or the data of the travel locus may be smoothed to create smooth curve data, and nodes may be extracted at predetermined intervals and used for road drawing. It may be data. As a result, as shown in FIG. 6, the road is drawn in a shape along the traveling locus of the vehicle, and the vehicle position mark 35 is correctly displayed on the road.
[0043]
On the other hand, if the number of times of mismatching is smaller than the number of times set in advance in step S21, the process ends without changing the map data.
[0044]
As described above, in the present embodiment, when the actual road shape and the road shape based on the map data are significantly different, the data of the road stored in the HDD 11 is read along the travel locus where the vehicle actually travels. Since the change is made, the vehicle position mark 35 can be correctly displayed on the road in the map image.
[0045]
Before changing the map data stored in the HDD 11, a message is displayed to ask the user whether or not to change the map data. The data may be replaced with data along the trajectory. In this case, it is preferable that the original map data (road link data) be backed up so that the original map data can be restored by a user's instruction.
[0046]
In the above-described embodiment, the map data, the mismatch section, and the travel locus are recorded in the same HDD 11, but the map data is stored in, for example, a DVD-ROM, and the mismatch section and the travel locus are stored in the flash memory. Etc. may be stored in the semiconductor memory. In this case, the control unit 18 compares the map data read into the buffer memory 17 with the mismatched section in the semiconductor memory. The data of the road read into the memory 17 is changed according to the data of the traveling locus in the semiconductor memory.
[0047]
(Second embodiment)
Hereinafter, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment in that processing when mismatching occurs more than a preset number of times in the same section is different, and other configurations are different from the first embodiment. Therefore, the description of the structure of the in-vehicle navigation device and the method of detecting the mismatch section is omitted.
[0048]
In the present embodiment, a section in which mismatching is likely to occur is detected and stored in the HDD 11 as in the first embodiment. Then, when the vehicle travels in the section, a forced matching process is performed to forcibly match the vehicle position mark on the road drawn by the map data.
[0049]
FIG. 7 is a flowchart illustrating a method of determining whether to perform the forced matching process.
[0050]
First, in step S31, the control unit 18 refers to the data storage area in the HDD 11 and determines whether or not a section to be run from now on is a section in which mismatching has occurred a predetermined number of times or more. If no, the process proceeds to step S32, and the display position of the vehicle position mark is determined by ordinary map matching.
[0051]
On the other hand, if it is determined in step S31 that the section to be traveled is a section in which mismatching has occurred a predetermined number of times or more, the process proceeds to step S33. In step S33, forcible matching processing is performed based on the map data and the traveling distance detected by the traveling distance sensor 6a so that the vehicle position mark is displayed on the traveling road.
[0052]
That is, the control unit 18 calculates the moving distance of the vehicle from the output of the distance sensor 6b, and calculates the moving amount on the road drawn by the map data. Then, the display position of the vehicle position mark is determined from the calculation result. In this case, the outputs of the GPS receiver 5 and the angle sensor 6a are basically ignored. Thereby, as shown in FIG. 8, the vehicle position mark 35 is correctly displayed on the traveling road.
[0053]
When the control unit 18 determines that the vehicle has passed the mismatched section, the control unit 18 terminates the forced matching process and executes a normal map matching process.
[0054]
In the present embodiment, even when the GPS receiver 5 cannot be used, for example, in a tunnel, the vehicle position mark can be displayed on the road in the map image.
[0055]
【The invention's effect】
As described above, according to the in-vehicle navigation device of the present invention, the section in which the mismatch has occurred is stored in the data storage means, and the section in which the mismatch has occurred more than a preset number of times uses the map data. It is determined that the difference between the road shape and the actual road shape is large, and the map data of the section is changed along the traveling locus of the vehicle. Thus, the road shape displayed on the display device becomes closer to the actual road shape, and the vehicle position mark can be displayed on the correct road.
[0056]
The same effect can be obtained by forcibly displaying a vehicle position mark on the road instead of changing the road data.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a vehicle-mounted navigation device according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating a map storage area and a data storage area provided in an HDD.
FIG. 3 is a diagram illustrating an example of a map image in which an actual road shape and a road shape drawn by map data are significantly different;
FIG. 4 is a flowchart illustrating a process of detecting a mismatch section;
FIG. 5 is a flowchart illustrating a process of determining whether to change map data.
FIG. 6 is a diagram illustrating an example in which map data is changed along a traveling locus of a vehicle.
FIG. 7 is a flowchart illustrating a method of determining whether to perform a forced matching process in the vehicle-mounted navigation device according to the second embodiment.
FIG. 8 is a diagram illustrating an example in which a display position of a vehicle position mark is determined by a forced matching process.
[Explanation of symbols]
3. Operation unit,
5 ... GPS receiver,
6… Self-contained navigation sensor,
7. Display device,
10. Navigation device body,
11 HDD (Hard Disk Drive),
17 ... buffer memory,
18 ... Control unit,
19: Map drawing unit,
21 ... operation screen / mark drawing unit
22 ... guidance route storage unit,
23: guidance route drawing unit,
25 ... Image synthesis unit
35 ... vehicle position mark.

Claims (5)

Map storage means for storing map data;
Vehicle position detecting means for detecting the current position of the vehicle;
A display device capable of displaying a map image,
Data storage means capable of reading and writing data,
Map data drawing means for drawing a map image to be displayed on the display device based on the map data,
A control unit that performs a map matching process on the current position of the vehicle detected by the vehicle position detection unit using the map data, and determines a display position of a vehicle position mark to be displayed on the map image,
The controller stores the section in which the mismatch has occurred in the data storage unit when a mismatch has occurred in the map matching process, and in the section where the mismatch has occurred a predetermined number of times or more, An in-vehicle navigation device characterized by changing map data of a section along a traveling locus of a vehicle. The in-vehicle navigation device according to claim 1, wherein the map storage unit and the data storage unit share a storage medium. Map storage means for storing map data;
Vehicle position detecting means for detecting the current position of the vehicle;
A display device capable of displaying a map image,
Data storage means capable of reading and writing data,
Map data drawing means for drawing a map image to be displayed on the display device based on the map data,
A control unit that performs a map matching process on the current position of the vehicle detected by the vehicle position detection unit using the map data, and determines a display position of a vehicle position mark to be displayed on the map image,
The controller stores, in the data storage section, a section in which the mismatch has occurred when a mismatch has occurred in the map matching process, and sets a vehicle in a section in which the mismatch has occurred a predetermined number of times or more. An on-vehicle navigation device, wherein a position mark is forcibly displayed on a road drawn by the map data. 4. The on-vehicle navigation according to claim 3, wherein a display position of a vehicle position mark is determined based on the travel distance of the vehicle and the map data in a section where the number of times of mismatching is equal to or greater than the preset number of times. apparatus. The in-vehicle navigation device according to claim 3, wherein the map storage unit and the data storage unit share a storage medium.

Images