JP3412272B2 - 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 in a superimposed manner on a map, and particularly when the vehicle turns right or left, the current position of the vehicle thereafter can be accurately displayed. About what you did.

[0002]

2. Description of the Related Art Conventionally, on the basis of a detection signal from a sensor mounted on a vehicle, the traveling distance and traveling direction of the vehicle are obtained to calculate the position of the vehicle, and based on the calculated position,
It is known that the current position of a vehicle is displayed on a map displayed on a CRT. However, since the detected values of the traveling distance detecting means and the azimuth detecting means include some errors, the calculated position of the vehicle obtained by integrating these detected values has an error. In order to correct such an error, the calculated position is compared with the test point on the map, and each time the vehicle passes the test point, the calculated position is adjusted to match the test point.

That is, in the map information of the vehicle traveling position display device, a road is approximated by a set of polygonal lines passing through its center line, and the midpoints of the lines, the end points of each polygonal line, the intersections of the roads, etc. are used as detection points. Then, when it is detected that the vehicle has traveled the distance from a certain test point to the next target test point, it is determined that the vehicle has passed the target test point, and the calculated position at that time is set to the position of the test point. After the correction, the current position of the vehicle is calculated based on the corrected calculated position.

However, such a correction method is good when the vehicle is straight ahead, but cannot be applied when the vehicle makes a right or left turn at an intersection or the like. In this case, therefore, another correction method is used for the vehicle. I am trying to correct the calculation position. FIG. 7 shows a case where a vehicle turns right or left at an intersection. When the vehicle turns right, the vehicle turns right from M1 to S1. In this case, if the midpoint P1c between the starting point P1s and the end point P1e of the vehicle's bending locus (turning locus) for a right turn is referred to as the right turn midpoint, the current position S1 of the vehicle is from the right turn midpoint P1c. Is corrected to the position Q1 by adding the travel distance of the above to the verification point P at the center of the intersection.

When the vehicle turns left, the vehicle is M
Turn left from 2 to S2. In this case, if the midpoint P2c between the start point P2s and the end point P2e of the vehicle's bending locus (turning locus) for a left turn is called the left turn midpoint, the current position S2 of the vehicle is from the left turn midpoint P2c. Is corrected to the position Q2 by adding the travel distance of the above to the verification point P at the center of the intersection. In other words, the position of the vehicle after completion of the right / left turn is the middle point P1c of the right / left turn,
The traveling distance from P2c to the current positions S1 and S2 is added to the verification point P at the center of the intersection.

However, in such a correction method, a position error occurs between the actual position of the vehicle after completion of the right / left turn and the calculated position after the correction. Here, when the vehicle makes a right turn, the middle point P1c of the right turn substantially coincides with the verification point P, and thus the position error E is considerably small. However, when the vehicle makes a left turn, the middle point P2c of the left turn and the verification point P2c. Since it is far away from P, its position error E becomes considerably large. The position error becomes larger as the road becomes larger.

As a solution to this problem, there is one disclosed in Japanese Patent Application Laid-Open No. 4-67300. this is,
When the vehicle makes a left turn at the intersection, Asin θ (where A is the width of the road and θ is the left turn angle) is added to the travel distance detected by the travel distance detecting means from the left turn middle point P2c. It is something that is done.

[0008]

[Problems to be Solved by the Invention] When a vehicle turns left,
It turns while drawing an arcuate path, and the length of the arcuate path also changes in magnitude depending on the left turn angle. However, the above-mentioned correction method disclosed in Japanese Patent Laid-Open No. 4-67300 travels on the road before turning left to the inspection point P, changes the direction at the inspection point P by the intersection angle of the roads before and after turning left, and then from the inspection point P. Since it is established on the assumption that the vehicle will travel on the road after turning left, an error still occurs when the vehicle turns while drawing an arc locus, and it is impossible to obtain such high correction accuracy.

The present invention has been made in view of the above circumstances, and an object thereof is to turn a vehicle in an arc locus while making a right or left turn regardless of the width of the road before and after the turn. Even if there is a situation in which the length of the arc locus at the time of turning varies depending on the turning angle, the calculated position of the vehicle can be corrected in consideration of them and the current position of the vehicle can be displayed accurately. To provide the equipment.

[0010]

A vehicle traveling position display device of the present invention includes a traveling distance detecting means for detecting a traveling distance of a vehicle, an azimuth detecting means for detecting a traveling azimuth of the vehicle, and a setting on a road map. Map storage means for storing map information including a plurality of certified points, position calculation means for calculating the current position of the vehicle based on the traveling distance detection means and the traveling azimuth, and the position calculation means. And a position correction means for correcting the current position of the vehicle by comparing the current position of the vehicle with a test point, and a display means for displaying the current position of the vehicle together with the road map obtained from the map information. The position correcting means, when a right or left turn of the vehicle is detected, the present position of the vehicle by a correction amount obtained based on the width of the road before and after the right or left turn, the bending angle of the vehicle, and the radius of the arc-shaped bending locus. To It is characterized in that positive.

In this case, the position correction means, when a right or left turn of the vehicle is detected, the current position of the vehicle after the end of the right or left turn is passed from the time when the vehicle passes through the midpoint of the arc-shaped bending locus. In the mileage of the vehicle, a verification point provided at the intersection of the center line of the road before turning left and right and the center line of the road after turning left and right, and the road after turning left and right from the end point of the arc-shaped bending locus. The arc length of the bending locus between the midpoint of the arc-shaped bending locus and the end point of the bending locus from the distance between the intersection of the perpendicular drawn to the centerline and the centerline of the road after the right / left turn. Can be corrected to the position where the correction amount obtained by subtracting is added.

Further, the bending angle of the vehicle is θ radians, the distance from the center line of the road before turning left to the running locus of the vehicle is W1, and the center line of the road after turning left to the running locus of the vehicle is turning. The distance is W2, and the radius of the curved trajectory of the vehicle is R
Then, the correction amount can be obtained from the following equation.

Correction amount = {W1 / sin (π-θ)} + {W
2 / tan (π−θ)} + R {1 / tan [(π−θ) /
2] -cos [(π-θ) / 2]}-R {(θ / 2) -si
n (θ / 2)} where W1 = {(total number of lanes on the road before turning left / 2)-
1} × 1 lane width W2 = {(total number of lanes of road after turning left / 2) -1} × 1
Lane width

[0014]

According to the above-mentioned means, when a right or left turn of the vehicle is detected, based on the width of the road before and after the right or left turn, the bending angle of the vehicle, and the radius of the arc-shaped bending locus (turning locus). Since the current position of the vehicle is corrected according to the required correction amount, the arc length of the bending locus of the vehicle turning right and left differs depending on the bending angle (turning angle), regardless of the width of the road before and after the turn. Even if there is such a situation, it is possible to correct the calculated position of the vehicle in consideration of them and display the current position of the vehicle with high accuracy.

In this case, the current position of the vehicle after the end of the right / left turn is corrected to a position obtained by adding the correction amount to the running distance of the vehicle from the time when the vehicle passes through the midpoint of the arc-shaped bending locus. The correction amount is a test point provided at the intersection of the center line of the road before turning left and right and the center line of the road after turning left and right, and from the end point of the arc-shaped bending locus to the center line of the road after turning left and right. Obtained by subtracting the arc length of the bending locus from the midpoint of the arc-shaped bending locus to the end point of the bending locus from the distance between the intersection of the dropped perpendicular and the center line of the road after the right / left turn. Therefore, even if the width of the road before and after turning right and left is small, even if the arc length of the bending trajectory changes depending on the bending angle, it is possible to absorb them and obtain an accurate current position. it can.

Further, the correction amount is {W1 / sin (π-
θ)} + {W2 / tan (π-θ)} + R {1 / tan
[(Π-θ) / 2] -cos [(π-θ) / 2]}-R
Since it is determined by the expression of {(θ / 2) -sin (θ / 2)}, the correction amount at the time of turning left or right can be applied to an actual road and easily determined.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a schematic configuration diagram of the vehicle traveling position display device, and a vehicle is equipped with a vehicle speed sensor 1 and a direction sensor 2. The vehicle speed sensor 1 detects the traveling speed of the vehicle, and this traveling speed is controlled by an electronic control circuit 3 described later.
The traveling distance of the vehicle is obtained by performing integration processing by means of the vehicle speed sensor 1 and the electronic control circuit 3 to constitute traveling distance detecting means.
Further, the azimuth sensor 2 as the azimuth detecting means detects the traveling azimuth of the vehicle, and in this embodiment, a geomagnetic sensor for detecting the geomagnetism to obtain the azimuth is used. However,
The azimuth sensor 2 may be a gyro compass or a azimuth sensor that accumulates steering angles of the vehicle obtained from the difference in rotation between the left and right steered wheels to obtain the azimuth.

Further, the vehicle traveling position display device has a map memory 4 as a map storage means, which is composed of a large-capacity storage device such as a compact disk. The map memory 4 stores, for example, map data of a predetermined range such as Tokyo, Aichi prefecture or Tokai region, and detection point data in which road features are written. Map data includes road shapes, road width and number of lanes, road names, buildings,
It consists of data for reproducing a map such as a place name and topography.

The detection point data is based on map data or actual measurement in order to correct the displayed vehicle position, the traveling direction of the vehicle obtained from the direction sensor 2, the traveling distance of the vehicle obtained from the vehicle speed sensor 1 and the like. This is the created data. In this embodiment, the road is approximated by a set of polygonal lines, and the midpoints of the lines, the end points of the corner polygonal lines, the intersections of the roads, etc. are used as the verification points. Then, it has the following information as data regarding these test points.

Test point number Absolute position of the test point (latitude, longitude) Area number including the test point (however, the area number is, for example, the division number when the whole of Japan is divided into several parts) Lines on both sides of the test point The number of other test points connected to the angle test point formed by the number of the other test points connected to the test point The distance to the other test point connected to the test point Connected to the test point Directions to other detection points The numbers, distances, and directions of other verification points in ,, and are the same as the number of other verification points in. Further, the absolute position of the test point, the distance between the test points, and the azimuths of other detection points are measured by actual measurement or from the map.

Further, the vehicle traveling position display device is provided with a control switch 5, which is a switch for inputting initial values by the vehicle occupant and selecting a map to be displayed. It is configured. The vehicle speed sensor 1, the relative azimuth sensor 2, the map memory 4, and the control switch 5 as described above are connected to the electronic control circuit 3, respectively. This electronic control circuit 3 is a well-known CPU
6. ROM that stores control programs and data in advance
7. A RAM 8 for storing a traveling locus obtained from a traveling distance and a traveling direction of the vehicle is provided, and an input / output circuit 9 is provided therein.
Are connected via a common path 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 the input / output circuit 9, and these signals, RO
Required processing such as calculation of the current position of the vehicle is executed based on the programs and data in M7 and RAM8, and a drive signal is output to CRT12 as a display means via input / output circuit 9 and CRT controller 11. Therefore, the electronic control circuit 3 functions as a position calculation means.

The CRT controller 11 is a CRT 1
2 is controlled, 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. It should be noted that the electronic control circuit 3 may be configured not to be mounted on the vehicle but to be provided on a fixed station and to transmit / receive data by an appropriate communication device to reproduce the vehicle position.

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, an occupant operates the control switch 5 to select a map displayed on the CRT 12 before starting the vehicle, and designates his / her vehicle position as the initial position Pb on this map. Alternatively, in addition to this, the previous stop position of the vehicle may be stored in the non-volatile memory and this position may be set as the initial position Pb.

When the vehicle starts running, the CPU
Reference numeral 6 integrates the traveling speed input from the vehicle speed sensor 1 to obtain the traveling distance, and integrates the change in the traveling direction input from the azimuth sensor 2 to obtain the traveling azimuth. It is stored in the RAM 8 as a locus.
Therefore, the CPU 6 functions as a traveling locus detecting means for detecting the traveling locus of the vehicle, and the RAM 8 functions as a traveling locus storing means for storing the traveling locus.

When the vehicle travels a certain distance, the current calculated position V calculated on the basis of the detected traveling distance and the traveling direction is displayed on the map of the CRT 12. When the vehicle passes a verification point Pi stored in advance in the map memory 4 as the vehicle travels, correction control processing for the calculated position V (position correction means)
Is done.

Here, the correction control process performed by the electronic control circuit 3 will be described with reference to the flowchart shown in FIG. First, the difference between the advancing direction after passing the detection point Pi detected by the direction sensor 2 and the advancing direction before passing 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 on a largely curved road. As shown in FIG. 4, the vehicle starts bending (turning starts).
When the angle θ formed between the traveling azimuth at the time point and the azimuth at the time when the bending ends (turning ends) becomes equal to or more than a predetermined angle, for example, π / 6 or more, it is determined to be bent.

If it is determined in step S1 that the vehicle does not bend, it is determined whether or not the vehicle has traveled the distance disn between the passing 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, etc. correspond to the inter-verification point distance disn and are stored in the map memory 4 in advance. When it is determined that the vehicle has traveled the distance disn, the radius r1 of the straight-ahead test circle C1 is calculated by the following mathematical formula 1 (step S3).

[0029]

## EQU1 ## r1 = K1.times.dis + e0 Here, K1 is an azimuth error coefficient mainly due to a detection error of the azimuth sensor 2 previously obtained by an experiment or the like, and this K1
× disn is the heading error term when traveling between the verification points.
Further, e0 is a setting error such as a map error.

Then, it is determined whether or not the calculated position V is within the straight-ahead verification circle C1 having the radius r1 calculated in the process of step S3 (step S4). This calculated position V is
It is the position calculated based on the detection values of the vehicle speed sensor 1 and the azimuth sensor 2 from the last-passed verification point.

When the calculated position V is within the straight-ahead test circle r1, it is determined that the test point Pi + 1 has been passed, and position correction processing is performed to make the calculated position V coincide with the test point Pi + 1. V is corrected (step S5). This calculation position V
Is calculated by, for example, obtaining a difference between the calculated position V and the position of the test point Pi + 1, and subtracting a value corresponding to the difference of the position from the calculated position V. Thereafter, the corrected calculation is performed. The position of the vehicle is calculated based on the position V. Figure 5
In this example, the pull-in process is executed at the test points P1, P3, P4 (P2 is excluded because it is a bend).

When it is determined in the processing of step S4 that the calculated position V is not within the straight-ahead verification circle r1,
A leaving process is executed (step S6). In this departure processing, it is determined that the vehicle is traveling on a place other than the road shown in the map, for example, a parking lot, and the calculated position V is not corrected and the calculated position V is directly displayed on the map of the CRT 12. indicate. On the other hand, when it is determined in the process of step S1 that the bending is performed, the radius r2 of the bending test circle C2 is calculated by the following mathematical formula 2 (step S7).

[0033]

## EQU2 ## r2 = K1 * disn + K2 * .SIGMA.disn + e1 Here, K1 and disn are the same as the values when calculating the radius r1 described above, and K2 is based on the calculation of the traveling distance obtained in advance by experiments or the like. Is a distance error coefficient, Σdisn is a traveling distance from the previous bending point, and in the example shown in FIG.
It is the distance traveled from 2 to the test point P5. This K2 × Σ
disn is a distance error term from the previous bending point. e1 is a setting error such as an azimuth error and a distance error.

Next, the maximum point Vma of curvature when bent.
x is calculated (step S8). In this embodiment, FIG.
As shown in, the angle between the straight line connecting the previous calculation position Vn-2 and the previous calculation position Vn-1, and the straight line connecting the previous calculation position Vn-1 and the current calculation position Vn. The curvature γn-1 is calculated. Then, the point at which this curvature is maximum is calculated as the maximum curvature point Vmax.

Subsequently, it is determined whether or not the curvature maximum point Vmax is within the bending test circle C2 calculated in the process of step S7 (step S9). When it is determined that the maximum curvature point Vmax is not within the bending test circle C2, the above-described separation processing is performed (step S6). When it is determined that the inspection circle C2 is inside the bending inspection circle C2, it is determined that the vehicle passes through an intersection having the inspection point Pi + 1 or a largely curved portion of the road. Then, the calculated position V is corrected (step S10).

The specific contents of this correction will be described by taking the case of turning left at the intersection shown in FIG. 1 as an example. This correction is made by the correction amount obtained based on the width of the road before and after the left turn, the bending angle of the vehicle, and the radius of the arc-shaped bending locus.
It is assumed that a vehicle traveling northward on the north-south road in FIG. 1 turns left at an intersection and reaches a position indicated by T1. The turning angle of the vehicle at the time of the left turn is set to θ radian, the midpoint between the starting point Ps and the end point Pe of the turning trajectory (turning locus) of the vehicle for the left turn is set to Pc, and the middle point Pc is turned to the left. It is called the midpoint. Further, A is a point where a perpendicular line drawn from the end point Pe of the curved locus to the center line B2 of the road after the left turn intersects with the center line B2 of the road after the left turn, and D is a distance between the verification point P and the intersection point A, The travel distance of the vehicle from the middle point Pc of the left turn to the end point Pe in the bending trajectory (the middle point P2c of the left turn to the end point P
E is the arc length up to 2e). The test point P is set at the intersection of the center line B1 of the road before turning left and the center line B2 of the road after turning left.

In the correction in this case, the calculated position V of the vehicle after the left turn is changed to the traveling distance L of the vehicle after the vehicle passes through the left turn middle point Pc, and the intersection point A from the verification point P is set.
This is done by adding the distance D up to and subtracting the running distance E from the middle point Pc of left turn to the end point Pe. That is, when the calculated position V is added to the position of the test point P by the travel distance L from the left turn middle point Pc to the T1 position, the travel distance E from the left turn middle point Pc to the end point Pe is overrun from the T1 position. , The traveling distance E from the middle point Pc of the left turn to the end point Pe is subtracted.

Specifically, such a correction amount can be obtained by calculation as described below. Now, let W1 be the distance from the center line B1 of the road before the left turn to the running locus of the vehicle, W2 be the distance from the center line B2 of the road after the left turn to the running locus of the vehicle, and R be the radius of the bending locus of the vehicle. .
Then, the distance from the verification point P to the intersection A is F, which is the intersection of the extension of the vehicle running path on the road before the left turn and the extension of the vehicle running path on the road after the left turn. G is the intersection of the vertical line dropped to the center line B2 of the road and the center line B2 of the road after the left turn, and the vertical line dropped to the center line B2 of the road after the left turn from the middle point Pc of the left turn and the road after the left turn. If the intersection with the center line B2 is H, the distance D from the verification point P to the intersection A is the distance d1 from the verification point P to the intersection G,
Distance d2 from intersection G to intersection H and intersection H to intersection A
It can be obtained by the sum with the distance d3 to.

The distance d1 is the center line B of the road before turning left.
I is the intersection of 1 and the extension of the vehicle's travel path on the road after a left turn, and the intersection of the perpendicular from the intersection I to the center line B2 of the road after the left turn and the center line B2 of the road after the left turn. If J, it can be obtained by the sum of the length d11 of the line segment PJ and the length d12 of the line segment JG. Therefore, focusing on the triangle PIJ, the angle between the line segment PJ and the center line B1 of the road before turning left is (π−θ), and the length of the line segment IJ is W2. D11 = W2 / tan
(Π−θ).

The center line B of the road before the left turn from the intersection F
Let K be the intersection of the vertical line dropped to 1 and the center line B1 of the road before the left turn, and focusing on the triangle FIK, the angle between the line segment IF and the center line B1 of the road before the left turn is (π-θ). ,
Since the length of the line segment FK is W1, the length of the line segment d12 is eventually W1 / sin (π-θ). Therefore, the distance d
1 becomes the following formula 3.

[Equation 3]   d1 = {W1 / sin (π-θ)} + {W2 / tan (π-θ)}

On the other hand, the distance d2 between the intersection G and the intersection H
Is equal to the length of the line segment GA minus the length of d3, and the length of the line segment GA is equal to the length of the line segment FPE.
Therefore, when the center of the bending locus is O and the triangle FOBPe is focused on, the angle formed by the line segment OF and the line segment FPE is (π
Since half of −θ) and the length of the line segment OPe are R, the length of the line segment FPe is R / tan [(π−θ) / 2].
Further, since the line segment OF passes through the left turn middle point Pc, the perpendicular line dropped from the left turn middle point Pc to the line segment OPe and the line segment OPe.
Let M be the intersection point with and, and pay attention to the triangle OMPc, since the length of the line segment OPc is R, d3 is R × cos [(π−
θ) / 2]. Therefore, the distance d2 is expressed by the following equation 4
It is represented by.

[Equation 4]   d2 = R {1 / tan [(π-θ) / 2] -cos [(π-θ) / 2]}

On the other hand, when attention is paid to the triangle OMPc, the angle formed by the line segment OPc and the line segment OM is θ / 2.
d3 can be represented by Rsin (θ / 2). In addition, the length from the middle point Pc of the left turn of the bending locus to the end point Pe is R (θ
/ 2). From the above, the correction amount is
The following formula 5 is obtained.

[Equation 5]   Correction amount = d1 + d2 + d3-(Distance E from the middle point Pc of the left turn to the end point Pe)         = {W1 / sin (π−θ)} + {W2 / tan (π−θ)} + R {1 / ta n [(π−θ) / 2] -cos [(π−θ) / 2]} + Rsin (θ / 2) −R (θ / 2)

By rearranging this, the following formula 6 is finally obtained.

[Equation 6]   Correction amount = {W1 / sin (π−θ)} + {W2 / tan (π−θ)} + R {1 / ta n [(π-θ) / 2] -cos [(π-θ) / 2]}-R {(θ / 2) -sin (θ / 2)}

Since the vehicle will turn left at the intersection before long on the road before turning left, the vehicle travels in the leftmost lane, and also in the road after turning left, for a while, in the leftmost lane of the road after turning left. To do. Therefore, W1 and W2 can be expressed by the following Equation 7.

[Equation 7]   W1 = {(total number of lanes on the road before turning left / 2) -1} x width of one lane   W2 = {(total number of lanes on the road after left turn / 2) -1} x width of one lane The width of one lane is generally set to about 3.5 m.

The correction amount can be obtained by the equation 6 as described above. Then, in the present embodiment, the correction amount is calculated by the above equation 6, and the result is tabulated and stored in the ROM 7 as the correction amount storage means. In this case, in the present embodiment, when the bending angle θ is π / 6 ≦ θ <π / 4, θ = π / 4, and when π / 4 ≦ θ ≦ 3π / 4, θ = θ and 3π / 4 <θ Sometimes, the correction amount is calculated with θ = 3π / 4 and stored in the ROM 7.

Therefore, the correction of the calculated position V in step S10 is carried out from the data of the verification point P by the number of lanes of the road before and after the left turn at the intersection, the bending angle θ (estimated from the bending locus, the bending angle detecting means), the bending. A corresponding correction amount is read from the ROM 7 using the radius R of the locus (estimated from the bending locus, bending radius detection means) as a parameter, and the position is corrected using the correction amount. It should be noted that also in the case of a right turn, position correction is performed in the same manner as described above. Now, after executing the above-mentioned step S5, step S6, and step S10 as described above, this correction control processing is once terminated, and thereafter,
This correction control processing is executed again.

As described above, according to the present embodiment, when a vehicle left / right turn is detected, a correction amount obtained based on the width of the road before and after the vehicle left / right turn, the vehicle bending angle, and the radius of the arc-shaped bending locus. Since the current position of the vehicle is corrected by, even if there is a difference in the width of the road before and after the turn, and even if there is a situation in which the arc length of the turning locus of the vehicle turning right and left differs depending on the turning angle, consider them. Thus, the calculated position of the vehicle can be corrected to accurately display the current position of the vehicle.

That is, when a right or left turn of the vehicle is detected, the position V of the vehicle after the end of the right or left turn is set to the traveling distance L of the vehicle from the time when the vehicle passes through the midpoint of the arc-shaped bending locus. , A test point provided at the intersection of the center of the road before turning right and left and the center of the road after turning left and right, and the perpendicular line dropped from the midpoint of the arc-shaped bending locus to the center of the road after turning left and right A correction amount obtained by subtracting the travel distance E of the vehicle between the midpoint of the arc-shaped bending locus and the end point of the bending locus from the distance D between the intersection of the center of the road after turning right and left. Since it is corrected to a position that adds, regardless of the width of the road before and after the turn, the size of the arc length of the bending trajectory,
The current position can be displayed with high correction accuracy.

Moreover, since the correction amount is calculated by the equation 6, the correction amount when turning right or left can be easily obtained for the actual road. Then, the first on the right side of Equation 6
The term is the correction amount of the calculated position deviation due to the width of each road before and after the left turn, the second item is the correction amount of the calculated position error due to the bending radius of the vehicle, and the third item is the bending from the midpoint to the end point of the bending trajectory. It has the meaning as the difference between the arc length of the track and the intersection of the perpendiculars drawn from the middle and end points of the curved track to the center line of the road after turning right and left. When turning left on a large road, the vehicle is actually traveling by correcting the calculated position V accurately even when turning left at a large angle of 90 ° or more or turning at a relatively small angle of about 30 °. The position can be displayed more accurately.

In this embodiment, the correction amount is stored in the ROM beforehand.
Since it is stored in 7, it is not necessary to calculate the correction amount one by one, and the position can be corrected in a short time. It should be noted that the correction amount may be calculated by Equation 6 each time the bending of the vehicle is detected. In this case, the electronic control circuit 3 detects the bending angle from the azimuth before bending and the azimuth after bending, the bending angle detecting means for detecting the midpoint of the bending locus from the bending locus, and the turning middle point detecting means for the bending locus. It functions as a bending radius detecting means for detecting a radius and as a correction amount calculating means for calculating a correction amount according to Formula 6.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a configuration of position correction according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a vehicle traveling position display device.

FIG. 3 is a flowchart for explaining the contents of correction control processing.

FIG. 4 is a diagram for explaining a bending angle detection configuration.

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

FIG. 6 is a diagram for explaining a maximum bending point detection configuration.

FIG. 7 is a diagram for explaining a conventional position correction configuration during bending.

[Explanation of symbols]

1 is a vehicle speed sensor (driving distance detecting means), 2 is a direction sensor (azimuth detecting means), 3 is an electronic control circuit (driving distance detecting means, position calculating means, position correcting means), 4 is a map memory (map storing means) , 12 are CRTs (display means).

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-27876 (JP, A) JP-A-59-208696 (JP, A) JP-A-2-51013 (JP, A) JP-A-2- 140615 (JP, A) JP-A 2-141613 (JP, A) JP-A 4-67300 (JP, A) JP-A 6-102052 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01C 21/00 G08G 1/09-1/16 G09B 29/00-29/10

Claims (3)

(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 storing map information including a plurality of test points set on a road map. A storage unit, a position calculation unit that calculates the current position of the vehicle based on the traveling distance detection unit and the traveling azimuth, and a comparison between the current position of the vehicle calculated by the position calculation unit and a verification point. A position correction unit that corrects the current position of the vehicle, and a display unit that displays the current position of the vehicle together with a road map obtained from the map information are provided, and the position correction unit detects a right or left turn of the vehicle. When
A vehicle traveling position display device for correcting the current position of the vehicle by a correction amount obtained based on the width of a road before and after a right / left turn, a bending angle of the vehicle, and a radius of an arc-shaped bending locus. 2. The position correcting means, when a right or left turn of the vehicle is detected, the current position of the vehicle after the right or left turn is ended, and the current position of the vehicle from the time point when the vehicle passes through the midpoint of the arc-shaped bending locus. In the mileage of the vehicle, the verification point provided at the intersection of the center line of the road before turning to the left and the center line of the road after turning to left and right, and the center of the road after turning left and right from the end point of the arc-shaped bending locus. From the distance between the intersection of the perpendicular line drawn on the line and the center line of the road after the right / left turn, the arc length of the bending locus between the midpoint of the arc-shaped bending locus and the end point of the bending locus is calculated. 2. The vehicle traveling position display device according to claim 1, wherein the position is corrected by adding a correction amount obtained by subtracting the correction amount. 3. The bending angle of the vehicle is θ radians, the distance from the center line of the road before turning to the vehicle to the running locus of the vehicle is W1, and the center line of the road after turning left to the running trajectory of the vehicle. 3. The vehicle traveling position display device according to claim 1, wherein the correction amount is obtained from the following equation, where W2 is a distance and R is a radius of a bending locus of the vehicle. Correction amount = {W1 / sin (π−θ)} + {W2 / tan (π
−θ)} + R {1 / tan [(π−θ) / 2] −cos
[(Π-θ) / 2]}-R {(θ / 2) -sin (θ /
2)} where W1 = {(total lanes on the road before turning left / 2)-
1} × 1 lane width W2 = {(total number of lanes of road after turning left / 2) -1} × 1
Lane width