JPH11325930A - Present position calculating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a present position from being displayed at positions at intervals. SOLUTION: When a present position received from a GPS receiver is isolated from a present position measured from a sensor output more than or equal to a specified threshold value, a processor 1 selects the present position obtained by the GPS receiver as the final present position. When the isolation is less than the threshold value, the processor 1 selects the measured present position as the final present position. In the case that a present position on a road is obtained by a map matching process, the obtained present position on a road is set as the final present position, only when the obtained position is not isolated more than the specified threshold value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for calculating a current position in a navigation device mounted on an automobile or the like.

[0002]

2. Description of the Related Art For example, in a navigation device mounted on an automobile, a current position of a vehicle is calculated by a technique called map matching and displayed on a map.

In this map matching technique, for example, the current position is calculated and displayed as follows.

That is, first, the relative displacement of the vehicle with respect to the last calculated current position is obtained from the running distance and the running direction obtained by using the vehicle speed sensor and the direction sensor. Then, by adding this to the last calculated current position, the current measurement position is obtained, this measurement position is set as the current position, and the process of displaying this is repeated.

[0005] Then, for each time or distance interval larger than the time or distance interval for obtaining the measurement position, the road map data is referred to, and a point on the road that most matches the current position or the running direction is determined. The distance between the upper point and the current position, the direction of the road, and the like are taken into consideration, this point is set as the current position, and this is displayed.

Conventionally, a position obtained by using a GPS (Global Positioning System) receiver (hereinafter referred to as “GPS position”) in consideration of the fact that an error is included in the measurement position.
Is compared with the above-mentioned measured position, and when they are separated by a predetermined value or more, the GPS position is used as the current position instead of the measured position.

[0007]

When the technique of correcting the provisional current position using a GPS receiver is applied to the above-described map matching technique, the following problems occur.

For example, when driving on a road that is not registered in the road map data, another road registered in the road map data exists nearby, and an incorrect current When the position is calculated or when the vehicle is running on a road registered in the road map data, there is another road registered in the road map data nearby. When the current position is calculated, the current position is displayed on another road. However, if the measured position calculated based on this current position is separated from the GPS position by a predetermined value or more, the GPS position that is separated from the current position on another road obtained by map matching is It will be displayed as the current position.

As a result, in such a case, the current position is displayed at discrete positions.

Accordingly, an object of the present invention is to provide a current position calculating device capable of further preventing the current position from being displayed at discrete positions.

[0011]

In order to achieve the above object,
The present invention is, for example, a current position calculating device for calculating a current position of a moving object, comprising: means for storing road map data representing a road map; Means for calculating, as a current position, a position obtained by adding the displacement of the moving object obtained from the traveling azimuth and the moving distance of the moving object after the calculated current position, and the position of the moving object obtained using a positioning system using satellites Means for obtaining the current position as the reception position; first correction means for correcting the current position to the reception position when the difference between the calculated current position and the reception position is equal to or greater than the predetermined threshold value; With reference to the road map data for each elapse of time,
The position on the road that most closely matches the measured position or the current position calculated at the time is calculated as a map matching position, and if the difference between the map matching position and the receiving position is less than the predetermined threshold, the current A second correction unit that updates the position to the calculated map matching position, and does not update the current position to the calculated map matching position when the difference between the map matching position and the reception position is equal to or greater than the predetermined threshold. The present invention provides a current position calculating device characterized by the following.

According to such a current position calculating device, the second correcting means updates the current position to the calculated map matching position when the difference between the map matching position and the reception position is equal to or larger than the predetermined threshold value. Not immediately,
The first correction unit does not correct the current position to a reception position located apart from the current position.

Therefore, in the case described above,
It is possible to prevent the current position from being displayed at discrete positions.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present position calculating device according to the present invention will be described below with reference to an application to an in-vehicle navigation device.

FIG. 1 shows a configuration of a navigation device according to this embodiment.

In the figure, reference numeral 1 denotes a processing device comprising a microprocessor and a memory; 2 a display device; 3 a drive device for accessing a storage medium such as a CD-ROM in which map data is stored; Is an input device for receiving the input of the instruction, and 5 is a sensor device including a vehicle speed sensor and a direction sensor, and 6 is a GPS receiver.

Next, the CD-ROM mounted on the drive device 3
FIG. 2 shows map data recorded on a storage medium such as the like.

Here, the CD-R mounted on the drive device 3
The map data recorded on a storage medium such as an OM will be described.

The map data is prepared for each rectangular geographical area called a mesh. As shown in FIG. 2, the map data of each mesh is composed of road data 21 provided for each road.
And the link information 23.

The road information 22 includes a road number 26 uniquely indicating a road, a road name 24 indicating a road name, a road type 27 indicating a type of the road (a toll road, a national road, a prefectural road) and the like. Other attribute 25 representing the information of the road.

The link information 23 includes link data 28 provided for each link constituting the road and representing link information. Here, the link is a straight line that approximates the shape position of the road as a set.

The link data 28 describes a link number 29 uniquely indicating a link and a cost 30 of the link.

The link data 28 includes a node number 32 uniquely indicating a node, a node coordinate 35 indicating a position of a node, and a link between the two nodes which are points at both ends of the two nodes. An adjacent node number list 34, which is a list of node numbers of all connected nodes, is included. Here, the connection between the links is always performed at the node. For example, at a crossroad, a node is provided at the center, and four links are connected to the node provided at the center. In this case, the adjacent node number list 34 of the node provided at the center describes the node numbers of the other four nodes of the four links connected to the own node.

In such a configuration, the processing device 1
The process of calculating the current running direction is repeated by adding the running direction displacement of the vehicle input from the direction sensor of the sensor device 5 to the previously obtained running direction. Further, the processing device 1 repeats the process of integrating the vehicle speed input from the vehicle speed sensor with time and calculating the traveling distance of the vehicle.

The processing unit 1 calculates the relative displacement from the last calculation of the current position to the present, which is obtained from the history of the calculated running azimuth and running distance, every time the vehicle travels for a certain distance. The process of obtaining the current measurement position is repeated by adding the current position to the current position.

Further, the processing device performs a map matching use current position calculation process described later to calculate the current position.

The processing device 1 controls the drive device 3 based on the calculated current position, the traveling direction of the vehicle, and the contents specified by the user via the input device 5 to read out map data. The map represented by the map data is displayed on the display device 2. At this time, a mark indicating the current position and the traveling direction of the vehicle is superimposed on the map and displayed on the map.

Hereinafter, the above-described map-matching-use current position calculation process will be described.

FIG. 3 shows a procedure of a current position calculation process using map matching according to the present embodiment.

As shown in the figure, in this processing, it is first determined whether or not a predetermined distance (for example, 20 m) has elapsed from the time when the previous map matching processing was performed (step 30).
0) If not, it is checked whether or not the absolute value of the difference between the GPS position Pg and the measurement position P1 is greater than or equal to the threshold Lth (step 304). And the threshold L
If it is less than th, the measurement position P1 is set as the current position (step 307), and the processing is terminated. If it is equal to or larger than the threshold value Lth, the GPS position Pg is set as the current position (step 3).
06), the process ends.

On the other hand, if it is determined in step 300 that the vehicle has advanced a certain distance (for example, 20 m) from the time when the previous map matching process was performed, the current position Po on the link is calculated on the link by map matching (step 300). 301). That is, the point on the link that most closely matches the measurement position calculated at that time is determined in consideration of the distance between the point on the link and the measurement position, the difference between the direction of the link and the traveling direction, and the like. This is set as the current map matching position Po.

Next, the calculated map matching current position
Check if Po is jumping (Step 3
02). Specifically, if the current position obtained by the previous map matching use current position calculation process is the map matching current position P0 'obtained in step 301 of the previous map matching use current position calculation process, the previously obtained map matching use current position calculation process is performed. If the road including the link where the map matching current position P0 ′ is located is different from the road including the link where the map matching current position P0 is found in step 301 of the current map matching utilizing current position calculation process, the position jump is performed. Judge that there is. If the current position obtained by the previous map matching use current position calculation process is the measured position p1 or the GPS position Pg, it is determined that the position is skipped.

If it is determined that the position is not skipped, the current position P0 of the map matching is set as the current position (step 305), and the process is terminated.

On the other hand, if it is determined that the position is skipped, it is determined whether or not the absolute value of the difference between the GPS position Pg obtained from the GPS receiver 6 and the map matching current position P0 is equal to or larger than the threshold Lth. Check (step 303).

If it is less than the threshold value Lth, the current position P0 of the map matching is set as the current position (step 305), and the process is terminated.

On the other hand, if it is equal to or greater than the threshold value Lth, it is further checked whether or not the absolute value of the difference between the GPS position Pg and the measurement position P1 is equal to or greater than the threshold value Lth (step 3).
04). If it is less than the threshold value Lth, the measurement position P1 is set as the current position (step 307), and the processing is terminated. If it is equal to or larger than the threshold value Lth, the GPS position Pg is set as the current position (step 306). To end.

As a result of the above processing, assuming that the current position P0 of the map matching obtained by the map matching is the current position, the absolute position of the difference between the measured position and the GPS position is equal to or larger than Lth. If the position is selected and the display of the current position jumps (step 303), the map matching current position P0 is not used as the current position in advance, and the map matching current position P0 is used as the current position only in other cases. I do. If the current position P0 of the map matching is not adopted as the current position, the GPS position is selected as the current position when the absolute position of the difference between the measured position and the GPS position is equal to or greater than Lth, and the measured position is selected as the current position when the absolute position is less than Lth. I do.

Therefore, according to the present embodiment, it is possible to prevent the current position from being displayed at discrete positions as in the related art.

Further, the processing apparatus 1 in the present embodiment comprises:
The computer may be a computer having a CPU, a memory, and an appropriate OS. In this case, each of the processes performed by the processing device
Is realized by executing a program describing the procedure of each process. In this case, these programs may be supplied to the processing device 1 via a storage medium such as a CD-ROM.

[0040]

As described above, according to the present invention, it is possible to prevent the current position from being displayed at discrete positions.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a navigation device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of map data according to the embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of the navigation device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing device 2 Display device 3 Drive device 4 Input device 5 Sensor device 6 GPS receiver

Claims (4)

[Claims] 1. A current position calculating device for calculating a current position of a moving body, comprising: means for storing road map data representing a road map; Means for calculating, as the current position, a position obtained by adding the displacement of the moving object obtained from the traveling azimuth and the moving distance of the moving object after the calculation of the current position, and the position of the moving object obtained by using a positioning system using a satellite. Means for obtaining a reception position; first correction means for correcting the current position to a reception position when a difference between the calculated current position and the reception position is equal to or greater than the predetermined threshold value; At each elapse, the road map data is referred to, and the measured position calculated at the time or the position on the road that most matches the current position is calculated as the map matching position, and the map matching position is calculated. If the difference between the matching position and the receiving position is less than the predetermined threshold, the current position is updated to the calculated map matching position, and if the difference between the map matching position and the receiving position is equal to or more than the predetermined threshold. A second correction unit that does not update the current position to the calculated map matching position. 2. The current position calculating device according to claim 1, wherein said second correction means is configured such that the calculated map matching position is on the same road as the previously calculated map matching position, and said second correcting means calculates said map matching position. When the current position is updated to the map matching position, the current position is updated to the calculated map matching position. 3. A method for calculating a current position of a moving object, comprising: calculating a current position calculated at the time point based on a traveling azimuth and a moving distance of the moving object after calculating the last calculated current position. Calculating the position obtained by adding the displacement of the moving object obtained as the current position; obtaining the position of the moving object obtained using the positioning system using satellites as the receiving position; and calculating the calculated current position and the receiving position. Correcting the current position to the receiving position when the difference is equal to or greater than the predetermined threshold value; and calculating the current position by referring to the road map data prepared in advance at every movement of a certain distance or at every certain time. The measured position or the position on the road that most matches the current position is calculated as the map matching position, and the difference between the map matching position and the receiving position is determined by the predetermined threshold. If the difference is less than the value, the current position is updated to the calculated map matching position. If the difference between the map matching position and the reception position is equal to or larger than the predetermined threshold, the current position is not updated to the calculated map matching position. And a current position calculation device. 4. A storage medium storing a program read and executed by an electronic computer, wherein the program stores a current position calculated at the time point and a current position calculated after the last calculated current position. Calculating the position obtained by adding the displacement of the moving object obtained from the traveling direction and the moving distance of the moving object as a current position; obtaining the position of the moving object obtained by using a positioning system using a satellite as a receiving position; Correcting the current position to the reception position when the difference between the calculated current position and the reception position is equal to or greater than the predetermined threshold; and storing the current position in the computer every time a certain distance has been moved or every certain time has elapsed. Refers to the road map data and compares the measured position calculated at the time or the position on the road that most matches the current position. If the difference between the map matching position and the receiving position is less than the predetermined threshold, the current position is updated to the calculated map matching position, and the difference between the map matching position and the receiving position is determined by the predetermined value. And a step of not updating the current position to the calculated map matching position if the threshold value is equal to or more than the threshold value of the storage medium.