JP3284773B2 - Vehicle running position display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle traveling position display device for displaying the current position of a vehicle on a map, and particularly, the vehicle is traveling because of the similarity between the traveling locus of the vehicle and the shape of the road. It relates to what specifies a road.

[0002]

2. Description of the Related Art Conventionally, based on a detection signal from a sensor mounted on a vehicle, a traveling distance and a traveling direction of the vehicle are calculated to calculate a position of the vehicle.
2. Description of the Related Art There is known a device that displays a current position of a vehicle on a map displayed on a CRT. However, since the detection values of the traveling distance detection means and the azimuth detection means include some errors, errors occur in the calculated position of the vehicle obtained by integrating these detection values. Therefore, the shape of the traveling locus of the vehicle is compared with the shape of the road, the road on which the vehicle is traveling is specified, and the calculated position is displayed on the road. And a correction is made to adjust the calculated position to the verification point every time the vehicle passes the verification point.

In such a map matching process, the following is known as an example of a conventional technique for determining whether or not a traveling locus of a vehicle and a shape of a road on a map coincide with each other. This is because it is estimated that the vehicle is traveling as shown in FIG. 8B while the arbitrary two points on the traveling locus of the vehicle are divided into a plurality of parts as shown in FIG. Similarly, two points on the road on the map to be divided are divided into a plurality of parts and line-divided. Then, each line segment of the traveling locus is superimposed on each line segment of the road on the map, and from the degree of coincidence, the road on which the vehicle is actually traveling and the road on the map for displaying the current position of the vehicle match. It is determined whether or not there is.

[0004]

In the road information, each point on the road is represented by an absolute position (latitude and longitude). Therefore, the direction of each of the above line segments on the map when determining the coincidence is east, west, north and south. Expressed in absolute orientation. Therefore, if the azimuth sensor mounted on the vehicle can detect an absolute azimuth such as a geomagnetic sensor, the above-described line segments of the traveling locus are also represented by the absolute azimuth. Each line segment can be directly compared.

However, when the direction sensor can detect only a relative direction such as a gyro,
Since the traveling direction of the vehicle can be captured only by a change in the traveling direction, when determining the degree of coincidence, first, each line segment of the traveling locus is rotated in accordance with each line segment of the road on the map. The line segment at the start point must be matched with the line segment at the start point of the road on the map, and then each line segment of the traveling trajectory must be compared with each line segment of the road on the map. As described above, in the determination of the degree of coincidence in the conventional map matching processing, if the azimuth sensor is a relative azimuth sensor, it is necessary to rotate the traveling locus, and there is a problem that the processing takes time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for driving a vehicle without performing rotation processing of a traveling locus, even if the direction detecting means can detect only a relative direction. It is an object of the present invention to provide a vehicle traveling position display device that can accurately determine the degree of coincidence between a trajectory and a candidate road.

[0007]

According to a first aspect of the present invention, there is provided a vehicle traveling position display device for detecting a traveling distance of a vehicle, a direction detecting unit for detecting a traveling direction of the vehicle, and road map information. And a map storage means for storing the calculated position of the vehicle calculated based on the traveling distance and the traveling direction on the display means together with the map information. Traveling locus detecting means for detecting a traveling locus of the vehicle based on the traveling locus,
Travel locus storage means for storing a travel locus of the vehicle detected by the travel locus detection means, and candidate road selection means for selecting a candidate road on which the vehicle travels from map roads stored in the map storage means; Each of a plurality of sections is divided between two points of the traveling locus stored in the traveling locus storage means and two points corresponding to the two points of the traveling locus among the candidate roads selected by the candidate road selecting means. Based on the difference between the angle between the straight line connecting the two points and the respective line segments in the travel locus and the angle between the straight line connecting the two points and the respective line segments on the candidate road, Determining means for determining whether or not the traveling locus matches the shape of the candidate road.

According to a second aspect of the present invention, there is provided a vehicle travel position display device.
2. The difference between an angle formed by a straight line connecting the two points on the travel locus and each line segment and an angle formed by the straight line connecting the two points on the candidate road and each line segment on the travel locus. Is determined, and it is determined whether or not the travel locus matches the shape of the candidate road based on the square root of the average value.

[0009]

When the map matching process is performed, a candidate road on which the vehicle travels is selected from the map roads stored in the map storage means. And, between the two points of the traveling locus and the selected candidate road, the 2
Each of the two points corresponding to the points is divided into a plurality of lines and divided into a plurality of lines, and the straight line connecting the two points on the traveling locus and the line segment and the straight line connecting the two points on the candidate road. It is determined whether or not the travel trajectory matches the shape of the candidate road based on the difference between the angles formed by the target road and the line segments. According to the determination of the degree of coincidence, each line segment of the traveling locus and each line segment of the candidate road are compared with an angle formed by the straight line with reference to one straight line, so that the traveling locus is adjusted to the candidate road. There is no need to perform rotation processing.

In this case, the average of the squares of the difference between the angle formed by the straight line connecting the two points and each line segment on the running locus and the angle formed by the straight line connecting the two points and each line segment on the candidate road is calculated. By determining whether or not the travel locus matches the shape of the candidate road based on the square root of the average value, the angle between a straight line connecting two points in the travel locus and each line segment and the angle between the two points on the candidate road are determined. Compared to the case where the degree of coincidence is determined based on the average value of the angle difference between the straight line connecting the lines and each line segment, there is no cancellation between the positive angle difference and the negative angle difference, so a more accurate match Degree judgment is possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 7 is a schematic configuration diagram of the vehicle traveling position display device. The vehicle is equipped with a vehicle speed sensor 1 and a relative direction sensor 2. The vehicle speed sensor 1 detects the traveling speed of the vehicle. The traveling speed of the vehicle is obtained by integrating the traveling speed by an electronic control circuit 3 described later. The traveling distance detecting means is constituted by the circuit 3. The relative azimuth sensor 2 includes a rate gyro, and detects a change in the traveling direction (angular velocity of yawing) of the vehicle. The change in the traveling direction detected by the relative direction sensor 2 is integrated by the electronic control circuit 3 to obtain the traveling direction of the vehicle. The relative direction sensor 2 and the electronic control circuit 3 determine the relative traveling direction. An azimuth detecting means is configured. The relative azimuth detecting means may be one that obtains the azimuth by accumulating the steering angles of the vehicle obtained from the rotation difference between the left and right steered wheels. Further, an absolute direction sensor such as a geomagnetic sensor may be used instead of the relative direction sensor 2.

The above-mentioned vehicle travel position display device has a map memory 4 as map storage means, which is constituted by a large-capacity storage device such as a compact disk. The map memory 4 stores, as map information, map data in a predetermined range such as Tokyo, Aichi or Tokai region, and detection point data in which road features are written. Map data includes road shape, road width, road name, building,
It consists of data for playing back maps such as place names and terrain.

The detected point data is based on map data or actual measurements in order to correct the displayed vehicle position, the traveling direction of the vehicle obtained from the relative direction sensor 2, the traveling distance of the vehicle obtained from the vehicle speed sensor 1, and the like. It is data created by In this embodiment, the road is approximated by a set of polygonal lines, and the midpoint of the line, the end point of the polygonal line, the intersection of the roads, and the like are set as test points. Then, it has the following information as data on these test points.

Test point number Absolute position of test point (latitude, longitude) Area number including test point (however, area number is, for example, a division number when the whole of Japan is divided into several parts) Polygonal lines on both sides of test point The number of other test points connected to the test point Number of other test points connected to the test point Distance to other test points connected to the test point Connected to the test point In addition, the number, distance, and direction of the other test points in are the numbers corresponding to the number of the other test points. Also,
The absolute position of the test point, the distance between the test points, and the azimuth to other test points are measured by actual measurement or from a map.

Further, the vehicle running position display device is provided with a control switch 5, which is a switch for the occupant of the vehicle to input an initial value and select a map to be displayed. It is configured.

The above-described vehicle speed sensor 1, relative direction sensor 2, map memory 4, and control switch 5 are connected to an electronic control circuit 3, respectively. The electronic control circuit 3 includes a well-known CPU 6, a ROM 7 for storing control programs and data in advance, and a RAM 8 for storing a traveling locus obtained from a traveling distance and a traveling direction of the vehicle.
An input / output circuit 9 is connected to them via a common bus 10.

The CPU 6 inputs signals from the vehicle speed sensor 1, the relative azimuth sensor 2, the map memory 4, and the control switch 5 through an input / output circuit 9, and outputs these signals, RO
M7, based on programs and data in the RAM 8, perform necessary processing such as functioning as a position calculating means for calculating the current position of the vehicle, and perform necessary processing on the CRT 12 via the input / output circuit 9 and the CRT controller 11. Output drive signal.

The CRT controller 11 includes a CRT 1
2 is displayed, the map data transferred from the electronic control circuit 3 is reproduced as a map on the screen of the CRT 12, and the calculated position of the vehicle transferred from the electronic control circuit 3 is displayed.
It is configured to be displayed on the currently displayed map. The electronic control circuit 3 may be provided in a fixed station without being mounted on a vehicle, and may be configured to reproduce data of a vehicle position by transmitting and receiving data with an appropriate communication device.

When a power switch (not shown) is turned on, the CPU 6 of the electronic control circuit 3 starts execution of arithmetic processing according to a program preset in the ROM 7.
In this embodiment, the occupant operates the control switch 5 to select a map displayed on the CRT 12 before starting the vehicle, and indicates the own vehicle position on this map as the initial position Pb. Alternatively, in addition to this, the last stop position of the vehicle may be stored in the nonvolatile memory, and this position may be set as the initial position Pb.

When the vehicle starts running, the CPU
6 obtains a traveling distance by integrating the traveling speed input from the vehicle speed sensor 1 and obtains a traveling direction by integrating a change in the traveling direction input from the relative direction sensor 2. It is stored in the RAM 8 as a running locus. Therefore, the electronic control circuit 3 functions as a running locus detecting means for detecting the running locus of the vehicle, and the RAM 8 functions as a running locus storing means for storing the running locus.

When the vehicle travels a certain distance, the current calculated position V calculated based on the detected traveling distance and the traveling direction is displayed on a map of the CRT 12. The verification points Pi (i) stored in advance in the map memory 4 as the vehicle travels
(The test point number), the correction control processing of the calculation position V is performed.

Here, the correction control process performed by the electronic control circuit 3 will be described with reference to a flowchart shown in FIG. First, a difference between the traveling azimuth after the detection point Pi detected by the relative azimuth sensor 2 and the traveling azimuth before the passage is obtained, and this difference is compared with a predetermined value to determine whether or not the vehicle is bent. Step S1). Here, the bending means, for example, a case where the vehicle turns right or left at an intersection or a largely curved road. As shown in FIG. 6, an angle γ between the azimuth before passing the verification point Pi and the azimuth after passing the verification point Pi. Is detected, and when the angle γ is equal to or larger than a predetermined angle, it is determined that the vehicle is bent.

If it is determined in step S1 that the vehicle does not bend, it is determined whether the vehicle has traveled the distance disn between the passed test point Pi and the next test point Pi + 1 (step S1).
2). As shown in FIG. 5, in this embodiment, between P0 and P1,
Distances between P1 and P2, between P2 and P3, between P3 and P4, and the like correspond to distances between test points disn, respectively, and are stored in the map memory 4 in advance. When it is determined that the vehicle has traveled the distance disn, it is determined whether or not the calculated position V is within a predetermined distance from the test point Pi + 1 (step S3). The calculated position V is a position calculated based on the detection values of the vehicle speed sensor 1 and the relative azimuth sensor 2 from the test point Pi passed last time. In FIG. 5, for example, the calculated position V is a position calculated from the test point P0.

When the calculated position V is within a predetermined distance from the test point Pi + 1, it is determined that the calculated position V has passed the test point Pi + 1.
The calculation position V is corrected to the test point Pi + 1 by performing a process of pulling the calculation position V (step S4). The correction of the calculation position V is performed, for example, by obtaining the difference between the calculation position V and the position of the test point Pi + 1, and subtracting a value corresponding to the difference between the positions from the calculation position V. The position of the vehicle is calculated based on the calculated position V corrected by the pull-in process. In the example of FIG. 5, the test points P1, P3, P4 (P2
Is excluded because of the bending). Next, a tracking process described later is executed (step S5), and thereafter, a calculation position V from the test point subjected to the pull-in process is calculated.

On the other hand, if it is determined in step S3 that the calculated position V is not within the predetermined distance from the test point Pi, a departure process is executed (step S6). In this departure process, it is determined that the vehicle is traveling on a place other than the road indicated on the map, for example, a parking lot, and the calculated position V is displayed on the CRT 12 map without correcting the calculated position V. indicate.

On the other hand, if it is determined in step S1 that the bending has occurred, it is determined whether or not the verification point Pi is within a predetermined distance from the calculation position V at the time of bending (step S7). If there is a test point Pi within a predetermined distance from V, it is determined that the detection point Pi has been passed, and the calculated position V when bent is drawn into the test point Pi to correct the calculated position V (step S8). Thereafter, the position of the vehicle is calculated based on the corrected calculated position V. Next, a tracking process described later is executed (step S
9) Thereafter, the calculation position V from the test point subjected to the pull-in process is calculated.

In step S7, the calculation position V is set to the test point P.
If it is not within the predetermined range from i, the above-mentioned departure processing (step S6) is executed, and the calculated position V is displayed on the map of the CRT 12 without correcting the calculated position V. When the processes of steps S5, S6, and S9 are executed, or when it is determined in the process of step S2 that the vehicle has not traveled the distance between the verification points, the control process is temporarily ended.

Next, the tracking processing in steps S5 and S9 will be described with reference to the flowchart shown in FIG. This tracking processing determines whether or not the road indicating the current position of the vehicle is coincident with the road on which the vehicle is actually traveling by comparing the traveling locus of the vehicle with the shape of the road. It is. Therefore, this tracking processing corresponds to the determination means.

In this tracking process, first, the running locus stored in the RAM 8 is read (step SA). For example, assuming that the vehicle has traveled from the point A to the point B as shown by the solid line L on the road shown in FIG. 2A, the travel locus shown by the solid line L0 in FIG. The road on which the point A exists is a point on the road (it may or may not be a verification point) on the road where it has been determined in the previous tracking process that the vehicle is actually traveling. When the absolute position of the vehicle is given by a satellite navigation system (GSP), a signpost (radio lighthouse), or the like, point A may be a point on the road indicated by the absolute position.

Next, a candidate road on which the vehicle is presumed to travel is selected from the map information (step SB, candidate road selection means). In the example shown in FIG. 2A, there are two intersections from point A toward the traveling direction of the vehicle.
As candidate roads, L1 when traveling straight at the first intersection as shown in FIG. 2C and the first road as shown in FIG.
After making a gentle right turn at the intersection, go straight at the second intersection L2, and as shown in FIG. 2 (e), make a gentle right turn at the first intersection and then make a right turn at the second intersection at a right angle. In this case, L3 is selected, and as shown in FIG. 2 (f), after making a gentle right turn at the first intersection and then turning left at a right angle at the second intersection. Then, on each of the candidate roads L1 to L4, data corresponding to the distance between the point A and the two points AB on the traveling locus L0 is read.

Thereafter, the traveling locus and the candidate road are divided into a plurality of sections at a fixed interval (for example, 10 m intervals) and divided into lines (step SC, line dividing means). The azimuth of a straight line connecting the (point A) and the end point (point B) is calculated (step SD, azimuth calculating means).
At this time, the azimuth of the straight line between the two points AB on the traveling locus may be a relative one indicated by the relative azimuth sensor 2 instead of an absolute azimuth indicated by east, west, north and south. Then, the degree of coincidence between the traveling locus and the candidate road is calculated, and the degree of coincidence is determined based on the calculated value (step SE, coincidence degree calculating means).

The principle of the coincidence determination will be described with reference to FIG. 3. As shown in FIG. 3A, the segment of the first segment of the traveling locus divided into a plurality of segments is K1, the segment of the second segment is K2, The segment of the third section is denoted by K3,... The segment of the last section is denoted by Kn, and the segment of the first section of the candidate road is R1, the segment of the second section is R2, as shown in FIG. Let the line segment of the third section be R3,... The line segment of the last section be Rn.

The degree of coincidence is determined by first determining A
The angle between the azimuth of the straight line LM connecting the two points B and the azimuth of each of the line segments K1 to Kn is obtained, and AB
An angle between the azimuth of the straight line LN connecting the two points and the azimuth of each of the line segments R1 to Rn is determined. Here, the straight line L1 and the line segment K1,
... .Theta.n, and the angles between the straight line L2 and the segments R1, R2,... Rn are .beta.1, .beta.2,. The degree of coincidence is calculated by Expression 1 shown below, and it is determined based on the value of the degree of coincidence whether or not the shape of the traveling locus matches the shape of the candidate road.

[0034]

(Equation 1)

The determination of the degree of coincidence according to Equation 1 is performed for each candidate road. Then, a candidate road having a degree of coincidence obtained for each candidate road smaller than a predetermined value is determined as a road on which the vehicle is currently traveling, and the current position is displayed on the road.
In the example of FIG. 2, the traveling locus L0 in (a) coincides with the candidate road L2 in (d), and the current position is displayed on the road L2. When the calculated value of the above formula 1 exceeds the predetermined value for any of the candidate roads, the road departs from the road on the map, for example, a vehicle enters a parking lot or a new road that is not on the map. Assuming that the vehicle has entered, the calculated position V is displayed on the map of the CRT 12 as it is in the same manner as in the departure processing.

As described above, according to the present embodiment, the angle θi formed between the straight line LM connecting the two points on the traveling locus and the respective line segments K1 to Kn, the line segment LN connecting the two points on the candidate road and the respective line segments R1
ＲRn, and the degree of coincidence between the traveling locus and the candidate road is determined based on the difference.
In other words, it is equivalent to superimposing the straight line LM and the straight line LN and comparing the angles of the line segments K1 to Kn of the traveling locus with the line segments R1 to Rn of the candidate road. For this reason, even if the traveling locus is indicated by the relative azimuth, the traveling locus does not need to be rotated in accordance with the candidate road, and the matching degree can be determined in a short time.

In this case, the degree of coincidence is determined by the root-mean-square shown in the above equation 1, so that the degree of coincidence is determined by simply averaging the difference between θi and βi.
Since the case where (θi−βi) becomes positive and the case where (θi−βi) become negative are not canceled out, it is possible to make a highly accurate determination.

In the above embodiment, the traveling locus and the candidate roads are divided into a large number. In addition, it is not necessary to divide the travel locus and the candidate road between the two points of AB at equal distances.
Thus, the division distance may be appropriately determined.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a process for determining the degree of coincidence between a traveling locus and a candidate road in one embodiment of the present invention.

FIG. 2 is a diagram showing an example of a traveling locus and candidate roads for explaining the content of a coincidence determination process;

FIG. 3 is a diagram for explaining the principle of the coincidence determination processing;

FIG. 4 is a flowchart showing a correction control process.

FIG. 5 is a diagram showing an example of a road for explaining the contents of a correction control process;

FIG. 6 is a diagram for explaining bending of the vehicle.

FIG. 7 is a schematic configuration diagram of a vehicle traveling position display device.

FIG. 8 is a diagram corresponding to FIG. 2 for explaining a conventional example.

[Explanation of symbols]

1 is a vehicle speed sensor (traveling distance detecting means), 2 is a relative direction sensor (traveling direction detecting means), 3 is an electronic control circuit (traveling distance detecting means, traveling direction detecting means, traveling locus detecting means, candidate road selecting means, determination Means, 4 is a map memory (map storage means), 6 is a CPU, 8 is RAM (running locus storage means), and 12 is a CRT (display means).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-243318 (JP, A) JP-A-3-77014 (JP, A) JP-A-64-41998 (JP, A) JP-A-4- 190283 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 21/00-21/36 G08G 1/0969 G09B 29/00-29/10

Claims (2)

(57) [Claims] 1. A travel distance detecting means for detecting a travel distance of a vehicle, a direction detecting means for detecting a traveling direction of the vehicle, and a map storage means for storing road map information. A display section that displays a calculated position of the vehicle calculated based on the azimuth together with the map information on a display unit, and a trajectory detection unit that detects a trajectory of the vehicle based on the mileage and the traveling azimuth; Travel locus storage means for storing a travel locus of the vehicle detected by the travel locus detection means, and candidate road selection means for selecting a candidate road on which the vehicle travels from map roads stored in the map storage means; Corresponding to between the two points of the travel locus stored in the travel locus storage means and between the two points of the travel locus among the candidate roads selected by the candidate road selection means. The two points are divided into a plurality of lines and divided into a plurality of lines, and the angle formed by the straight line connecting the two points and the line segments in the traveling locus and the straight line connecting the two points on the candidate road and the line segments A vehicle travel position display device comprising: determination means for determining whether or not the travel locus matches the shape of the candidate road based on a difference in angle between the vehicle travel position and the candidate road. 2. The method according to claim 1, wherein the determining unit determines an angle formed between the straight line connecting the two points and the respective line segments in the travel locus and an angle formed between the straight line connecting the two points and the respective line segments on the candidate road. 2. The vehicle travel position display device according to claim 1, wherein an average of values obtained by squaring the difference is obtained, and whether or not the travel locus matches the shape of the candidate road is determined based on a square root of the average value.