JP2511252B2 - Driving route display device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a travel route display device for displaying a current position and a travel locus of a moving body such as an automobile on a screen on which a map is set in advance.

2. Description of the Related Art Recently, as will be described later in detail, for example, when driving a vehicle in a non-guidance area, in order to provide appropriate guidance so that the driver does not get lost from the planned course, the vehicle travels. Along with this, the distance detector detects the running distance according to the vehicle speed and the direction detector detects the traveling direction and its change momentarily, and the current position on the two-dimensional coordinates of the automobile etc. is sequentially calculated from these detected values. It is possible to allow the driver to confirm the current position by displaying the result by continuously changing point information on a display screen on which a map such as a road is displayed in advance while storing and storing the result. Have been developed.

However, in such a travel route display device, it is inevitable that a position error will occur due to factors such as detection accuracy when distance detection and direction detection are performed according to the traveling state of an automobile, etc. Therefore, the error accumulates and the current position and the running trajectory up to that point deviate from the road on the map, and it becomes impossible to determine which road on the map the vehicle is driving. There's a problem.

Conventionally, in order to correct the position error, a method has been considered in which the correction is made based on the relationship between the road pattern on the map and the traveling locus pattern of the vehicle. In other words, in order to find a road pattern that matches the trajectory pattern of the vehicle, some routes that the vehicle seems to have taken are selected from among the complicatedly connected roads, and the suitability of the pattern is determined for each. It is considered that the road having the best matching pattern is passed by the vehicle, and the traveling locus of the vehicle is superimposed and displayed on the corresponding road portion on the map.

However, if such a correcting means is adopted, an extremely large number of road patterns will be extracted by searching for and extracting the route that the vehicle seems to have traveled on the map in which the roads are complicated and complicated. It takes a lot of time to perform the process for matching the traveling locus pattern of the vehicle for one.

The present invention has been made in consideration of the above points, and while determining the traveling locus so that the traveling locus does not deviate from the road on the map, the traveling locus of the vehicle on the map together with its current position The present invention provides a travel route display device for displaying.

Structure The present invention is one of pattern recognition techniques for achieving the object.
By using the relaxation method, which is one of the two methods, each pattern of the road on the map and the traveling path of the vehicle is divided into line segments, and pattern recognition by polygonal approximation is performed to match the two. A means for displaying the traveling locus according to the line segment of the selected road is provided.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an example of the configuration of a traveling route display device according to the present invention. The basic configuration thereof is, for example, a photoelectric type or an electromagnetic type which outputs a pulse signal per unit traveling distance in accordance with the rotation of an automobile tire. A distance sensor 1 of a type or a mechanical contact type, and a direction sensor 2 that outputs a signal proportional to a direction change amount accompanying the traveling of the vehicle, such as a gyroscope that detects a change in angular velocity in the yaw direction,
The number of pulse signals from the distance sensor 1 is counted to measure the traveling distance of the automobile, and the change in the traveling direction is determined according to the output signal of the direction sensor 2 so that the traveling distance of the automobile is two-dimensionally coordinated. Signal processing device 3 including a CPU, a program ROM, a control RAM, etc., for performing the centralized control of the entire system by sequential calculation, and the two-dimensional coordinates that change every moment obtained by the signal processing device 3. A traveling locus storage device (RA that sequentially stores the data of the upper position and retains it as finite continuous position information corresponding to the current position of the vehicle.
M) 4 is a map information storage medium 5 in which a plurality of map data relating to the position of the road on the XY coordinates are stored in advance in a file unit, and a memory for selectively reading out a necessary map file from the storage medium 5. A map image is displayed on the screen according to the medium reproducing device 6 and the read map file, and the current position of the automobile, the traveling locus up to that point, and the traveling locus up to that point are displayed based on the position data stored in the traveling locus storage device 4. A display device 7 for updating and displaying the current traveling direction on the same screen every moment and an operation command for the signal processing device 3 and selection designation of a map to be displayed on the display device 7 and departure of a car on the displayed map. Set points, change the direction of the displayed map and travel locus, shift the display position, partially enlarge the map and travel locus, display It is configured by an operation device 8 capable of appropriately changing display mode settings such as selection of a scale factor.

In such a configuration, the selectively read map is displayed on the screen of the display device 7 and is preset by the signal processing device 3 in accordance with the vehicle traveling from the starting point set on the map. Current position (x, y) on XY coordinates according to the scale factor of the created map
Is obtained by calculation every second, and the calculation result is sequentially sent to the traveling locus storage device 4 to update its stored contents, and the stored contents are constantly read and sent to the display device 7. As a result, on the display device 7, as shown in FIG. 2, a display mark M1 indicating the current position of the automobile on the map displayed on the screen, a display mark M2 indicating the traveling direction of the automobile at the current position, and a departure mark. A running locus display mark M3 from the point S to the current position is simulated and displayed following the running state of the automobile.

The above configuration and operation are the same as those of the conventional travel route display device described in the adventure.

Therefore, in such a traveling route display device, as shown in FIG. 3, the current position and the traveling locus up to that point gradually deviate from the road on the map as the vehicle travels due to the accumulated error described above, Eventually, it will not be possible to determine which point on the map the car is currently traveling.

The present invention relates to such a travel route display device, and in particular, in the signal processing device 3, data of a travel locus obtained by storing and holding in a memory the data of the current position which changes with the travel of the moving body. Based on the map data, a method for approximating the traveling locus and the road on the map into polygons by line segments, and a relaxation method for matching each pattern of the polygonal approximated traveling locus and the road on the map. The means used and the means for correcting the current position of the moving body so that the traveling locus is on the road of the line segment with which the matching is taken are taken.

A conventionally known method is applied as a specific method for approximating each pattern of the road on the map and the traveling locus of the vehicle into a polygon.

FIG. 4 shows a processing procedure in the signal processing device 3 in that case. First, the XY obtained as described above is used.
Based on the traveling locus on the coordinates, it is subjected to polygonal approximation by line segments, and a table of a list showing the positional relationship on the XY coordinates of each polygonal line segment is created,
Next, the candidate road segment on the map that is likely to match each line segment of the traveling locus is selected by corresponding to each line segment in the table in which the road on the map is approximated to a polygon by the XY coordinates in advance and similarly listed. To do. It should be noted that the traveling locus to be processed here may be a traveling locus from the starting point to the current position, or, for example, from the past position of the vehicle a certain time before the current time to the current position. You may make it take the running locus to reach a position.

Next, the matching method of the pattern of each candidate line segment on the selected map and each line segment of the traveling locus is gradually relaxed by gradually relaxing the matching method, that is, by loosening the degree of matching first. In addition to using the method described below, we will try to match the line segment that is currently the recognition target while checking the connection with the line segment that was previously matched,
A matching index indicating the degree of correspondence of each line segment is obtained by arithmetic processing, and the matching index is updated. Here, the matching index is the probability that the line segments will match, and pattern recognition will be repeated until a 100% match is found among the selected candidate line segments on the map that correspond to the line segments of the running trajectory. Will be done.

Finally, a set of line segments on the map corresponding to each line segment of the travel locus is taken 100%, and the display unit 7 displays the travel route together with the map, assuming that the set of line segments is the travel route of the vehicle. Let

As a line segment list of the travel locus, as shown in FIG. 5, the coordinate position (Xsi, Ys) of the starting point of the line segment i (i = 1 to m) of the travel locus on the XY coordinates approximated by the polygon is used.
i), the coordinate position (Xei, Yei) of the end point is calculated,
Further, the inclination θi and the length Li of the line segment i are obtained by predetermined arithmetic processing, and a table as shown in Table 1 below is created, for example.

Also, as the road line segment list on the map,
As shown in the figure, a line segment j (j =
1 to n), the coordinate position (Xaj, Ysj) of the starting point and the inclination θ
j, length Lj, and coordinate data (Xej, Yej) of the end point are respectively taken, and the number of each line segment connected to the start point and the end point of the line segment j, together with a table as shown in Table 2 below. Created. The road line segment list table may be stored in advance in the map information storage medium 5 together with the map data, and the contents of the table may be read when the patterns are matched.

Further, as a specific method for selecting a candidate line segment on the map corresponding to the line segment i of the traveling locus, a difference in inclination between the line segment i of the traveling locus and a line segment j on the map is dθ, and a difference in length. To
dL, the distance between the start points is dS, and the distance between the end points is dE, and the respective allowable values α1, α2, α3, α predetermined according to the respective feature quantities are set.
4, the line segment on the map that satisfies all the conditions of the following formulas (1) to (4) is selected as the candidate line segment.

dθ = | θi−θj | α1 (1) dL = | Li−Lj | α2 (2) Further, the line segment i of the traveling locus and the candidate line segment j on the map
When the matching index with and is Pi (j), it is obtained according to the following arithmetic expression.

First, how much the feature amounts between the line segment of the traveling locus and each candidate line segment are different is calculated according to the following equation.

P′i (j) = {1-ω1 × max (dθ−β1,0) −ω2
× max (dL-β2,0) -ω3 × max (dS-β3,0) -ω4 ×
max (dE−β4,0)} (5) Here, ω1 to ω4 are weights of the respective feature amounts, which vary depending on the degree of error of the sensors 1 and 2 used in the travel route display device. is there. Further, β1 to β4 are error ranges with respect to the minute difference of each feature amount.

Next, the matching index Pi (j) is obtained by normalizing it according to the following equation.

Further, the relevance coefficient at the time of updating is shown in FIG. 7 as to the connection relationship (angle difference,
The presence / absence of connection) and the connection relationship between the start point side and the end point side of the candidate line segment j on the map,
Fitting coefficient Γik on the starting point side of line segment j with respect to line segment i
(J, l) is calculated by the following equation.

Γik (j, l) = {1-ωr × max (| θi−θk | − | θj
−θl | −γ, 0)} × D (7) The matching coefficient Γim (j, n) on the end point side is also obtained in the same manner.

Here, ωr is a weight with respect to the adaptation coefficient, and changes depending on the degree of error of each of the sensors 1 and 2 used in the travel route display device. Further, γ is an error range with respect to the adaptation coefficient, D is a connection coefficient, and takes a value of 1 if connected and 0 if not connected.

The updating of the matching index is performed by the arithmetic processing of the following equation.

However, Qi (j) = 1/2 [max {Γ ^n-1 ik (j, l) · Pk (l)} + ma
x {Γ ^n-1 im (j, n) · Pm (n)} (9)

Now, for example, as shown in FIG. 8, the traveling locus is line segments a, b,
given by c, and are selected as candidate line segments for the line segment a, and are selected as candidate line segments for the line segment b, and ,,, are selected as candidate line segments for the line segment c. I'll think about it.
In the figure, A, B, and C indicate traveling sections of the vehicle.

First, when the vehicle is in section A, the difference d between the slopes of the line segments
The candidate line segment is selected by using θa and the distance dSa between the start points as the feature quantity, and then the matching index Pa (1), Pa (2), Pa of each candidate line segment for the line segment a is selected.
Find (3) respectively. At that time, the matching index is 10
The candidate line segment with 0% is taken as the mileage.

Next, when the vehicle is in the section B: 1. With respect to the line segment a, the difference dθa in the inclination of the line segment and the difference dLa in the length
The candidate line segments are selected by using the distance dSa between the start points and the distance dEa between the end points as feature quantities,
, Matching index P ⁰ a (1), P ⁰ a (2), P ⁰ a
Find (3) respectively.

2. The difference between the line segment b and the inclination of the line segment dθb, the distance between the start points
A candidate segment is selected by using dSb, as a feature quantity, and the matching index P ⁰ b of each candidate segment ,,
(4), P ⁰ b (5), and P ⁰ b (6) are obtained.

At this time, if no candidate line segment that matches 100% with each line segment a, b is obtained, the first update is performed.

P ¹ a (1) = Γ ab (1,4) × P ⁰ b (4) × P ⁰ a (1) = Qa (1) × P ⁰ a (1) P ¹ a (2) = Γ ab (2, 4) × P ⁰ b (4) × P ⁰ a (2) = Qa (2) × P ⁰ a (2) Γ ab (3,5) × P ⁰ b (5)> Γ ab (3,6) × P ^{When 0} b (6), P ¹ a (3) = Γ ab (3,5) × P ⁰ b (5) × P ⁰ a (3) = Qa (3) × P ⁰ a (3) Γ ab (1 , 4) × P ⁰ b (1) <Γab (2,4) × P ⁰ b (2), P ¹ b (4) = Γab (2,4) × P ⁰ a (2) × P ⁰ b (4) = Qb (4 ) × P 0 b (4) P 1 b (5) = Γab (3,5) × P 0 a (3) × P 0 b (5) = Qb (5) × P ⁰ b (5) P ¹ b (6) = Γ ab (3,6) × P ⁰ a (3) × P ⁰ b (6) = Qb (6) × P ⁰ b (6) Further, at this time, each line segment If no candidate line segment that matches 100% with a, b is obtained, the second update is performed.

P ² a (1) = Γ ab (1,4) × P ¹ b (4) × P ¹ a (1) = Γ ab (1,4) × Qb (4) × P ⁰ b (4) × Qa (1 )
× P ⁰ a (1) = {Qa (1)} ² × Qb (4) × P ⁰ a (1) P ² a (2) = Γ ab (2,4) × P ¹ b (4) × P ¹ a (2) = Γab (2,4) × Qb (4) × P ⁰ b (4) × Qa (2)
× P ⁰ a (2) = {Qa (2)} ² × Qb (4) × P ⁰ a (2) Γab (3,5) × P ¹ b (5)> Γab (3,6) × P ¹ When b (6), P ² a (3) = Γab (3,5) × P ¹ b (5) × P ¹ a (3) = Γab (3,5) × Qb (5) × P ⁰ b (5) x Qa (3)
× P ⁰ a (3) = {Qa (3)} ² × Qb (5) × P ⁰ a (3) Γab (1,4) × P ¹ b (1) <Γab (2,4) × P ¹ When b (2), P ² b (4) = Γab (2,4) × P ¹ a (2) × P ¹ b (4) = Γab (2,4) × Qa (2) × P ⁰ a (2) x Qb (4)
× P ⁰ b (4) = {Qb (4)} ² × Qa (2) × P ⁰ b (4) P ² b (5) = Γab (3,5) × P ¹ a (3) × P ¹ b (5) = Γab (3,5) × Qa (3) × P ⁰ a (3) × Qb (5)
× P ⁰ b (5) = {Qb (5)} ² × Qa (3) × P ⁰ b (5) P ² b (6) = Γab (3,6) × P ¹ a (3) × P ¹ b (6) = Γab (3,6) × Qa (3) × P ⁰ a (3) × Qb (6)
× P ⁰ b (6) = {Qb (6)} ² × Qa (3) × P ⁰ b (6) Similarly, if no candidate line segment that matches 100% with each line segment a, b is obtained. Will update the third time, the fourth time, and so on.

Finally, the candidate line segment with a matching index of 100% is used as the vehicle travel route.

Next, when the vehicle is in the section C: 1. With respect to the line segment a, the difference in inclination of the line segment dθa, the difference in length dLa,
The candidate line segments are selected by using the distance dSa between the start points and the distance dEa between the end points as feature quantities,
, Matching index P ⁰ a (1), P ⁰ a (2), P ⁰ a
Find (3) respectively.

2. With respect to the line segment b, the difference dθb in the inclination of the line segment, the difference dLb in the length,
The candidate line segments are selected by using the distance dSb between the start points and the distance dEb between the end points as the feature quantity,
, Matching indices P ⁰ b (4), P ⁰ b (5), P ⁰ b
Find (6) respectively.

3. The difference between the line segment c and the inclination of the line segment dθc, the distance between the start points
Candidate line segments are selected by using dSc as a feature amount, and matching indices P ⁰ c (7), P ⁰ c (8), P ⁰ c (9), of the selected candidate line segments ,, respectively. P ⁰ c
Find each (10).

At this time, if a candidate line segment that 100% matches each line segment a, b, c cannot be obtained, the first update is performed.

P ¹ a (1) = Γ ab (1,4) × P ⁰ b (4) × P ⁰ a (1) = Qa (1) × P ⁰ a (1) P ¹ a (2) = Γ ab (2, 4) × P ⁰ b (4) × P ⁰ a (2) = Qa (2) × P ⁰ a (2) Γ ab (3,5) × P ⁰ b (5)> Γ ab (3,6) × P ^{When 0} b (6), P ¹ a (3) = Γ ab (3,5) × P ⁰ b (5) × P ⁰ a (3) = Qa (3) × P ⁰ a (3) Γ ab (1 , 4) × P ⁰ a (1) <Γab (2,4) × P ⁰ a (2), and Γbc (4,7) × P ⁰ c (7) <Γbc (4,8) × P ⁰ c When (8), P ¹ b (4) = Qb (4) × P ⁰ b (4) where Qb (4) = 1/2 {Γab (2,4) × P ⁰ a (2) + Γbc (4,8) × P ⁰ c (8)}.

When Γbc (5,9) × P ⁰ c (9)> Γbc (5,10) × P ⁰ c (10), P ¹ b (5) = Qb (5) × P ⁰ b (5) where , Qb (5) = 1/2 {Γab (3,5) × P ⁰ a (3) + Γbc (5,9) × P ⁰ c (9)}.

P ¹ c (7) = Γ bc (4,7) × P ⁰ b (4) × P ⁰ c (7) = Qc (7) × P ⁰ c (7) P ¹ c (8) = Γ bc (4, 8) × P ⁰ b (4) × P ⁰ c (8) = Qc (8) × P ⁰ c (8) P ¹ c (9) = Γbc (5,9) × P ⁰ b (5) × P ⁰ c (9) = Qc (9) × P ⁰ c (9) P ¹ c (10) = Γ bc (5,10) × P ⁰ b (5) × P ⁰ c (10) = Qc (10) × P ⁰ c (10) Further, at this time, if a candidate line segment that 100% matches each line segment a, b is not obtained, the second update is performed.

P ² a (1) = Γab (1,4) × P ¹ b (4) × P ¹ a (1) = Γab (1,4) × Qb (4) × P ⁰ b (4) × Qa (1 ) × P ⁰ a (1) = {Qa (1)} ² × Qb (4) × P ⁰ a (1) P ² a (2) = Γab (2,4) × P ¹ b (4) × P ¹ a (2) = Γ ab (2,4) × Qb (4) × P ⁰ b (4) × Qa (2) × P ⁰ a (2) = {Qa (2)} ² × Qb (4) × P ⁰ a (2) P ² a (3) = Γ ab (3,5) × P ¹ b (5) × P ¹ a (3) = Γ ab (3,5) × Qb (5) × P ⁰ b ( 5) × Qa (3) × P ⁰ a (3) = {Qa (3)} ² × Qb (5) × P ⁰ a (3) P ² b (4) = Qb (4) × P ¹ b ( 4) where Γab (2,4) × P ¹ a (2)> Γab (1,4) × P ¹ a (1), Γbc (4,8) × P ¹ c (8)> Γbc ( When 4,7) × P ¹ c (7), Qb (4) = 1/2 {Γab (2,4) × P ¹ a (2) + Γbc (4,8) × P ¹ c (8)} Is.

P ² b (5) = Qb (5) × P ¹ b (5) where Γbc (5,9) × P ¹ c (9)> Γbc (5,10) × P ¹ c (10) , Qb (5) = 1/2 {Γab (3,5) × P ¹ a (3) + Γbc (5,9) × P ¹ c (9)}.

P ² c (7) = Γ bc (4,7) × P ¹ b (4) × P ¹ c (7) = Qc (7) × P ¹ c (7) P ² c (8) = Γ bc (4, 8) × P ¹ b (4) × P ¹ c (8) = Qc (8) × P ¹ c (8) P ² c (9) = Γbc (5,9) × P ¹ b (5) × P ¹ c (9) = Qc (9) × P ¹ c (9) P ² c (10) = Γbc (5,10) × P ¹ b (5) × P ¹ c (10) = Qc (10) × P ¹ c (10) In the same manner, if a candidate line segment that 100% matches each line segment a, b, c cannot be obtained, update is performed for the third time, the fourth time, and so on.

Finally, the candidate line segment with a matching index of 100% is used as the vehicle travel route.

As described above, in the present invention, the traveling locus of the vehicle and the road on the map are polygon-approximated by line segments, and a list of each line segment approximated by the polygon is created. Because the pattern recognition by the relaxation method is performed every minute on the entire map, there is no need to select multiple roads on the map that are the target of pattern recognition for the traveling locus, as is the case in the past. Even in a complicated case, the pattern recognition can be performed quickly and surely, and the accuracy of the pattern recognition by the line segment correspondence increases as the traveling distance of the vehicle increases.

In addition, since the matching of line segments that approximate polygons is performed over the entire map, the line segment of the running locus that cannot be matched will be used as the route when the vehicle travels on a road that is not on the map. You will be able to judge.

Effect As described above, in the travel route display device according to the present invention, the road on the map and the travel locus of the moving body are polygonally approximated by the line segment, thereby effectively reducing the load of the matching process and traveling. It is possible to optimally match each pattern of the trajectory and the road on the map.
Then, by the simple matching process, the road currently traveling is searched from the map in which the roads are intricately complicated, and the traveling locus is matched with the searched road, so that the predetermined location on the road is determined. It has an excellent advantage that the present position where the position error occurs is accurately corrected.

Further, according to the present invention, in the case of displaying on the road map projected on the screen of the traveling locus to show what route the mobile body is traveling on the road map,
There is an advantage that the running locus itself that has deviated from the road by accumulating position errors can be adjusted to the currently running road portion on the map.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a traveling route display device according to the present invention, FIG. 2 is a diagram showing an example of display contents in the embodiment, and FIG. 3 is a state in which a traveling locus deviates from the road. FIG. 4, FIG. 4 is a flow chart showing a processing procedure of pattern recognition in carrying out the present invention, FIG. 5 is a view showing a traveling locus approximated by a polygon by a line segment, and FIG. 6 is a polygon by a line segment. Figure 7 shows a road on an approximated map
FIG. 8 is a diagram showing a correspondence relationship between a traveling locus approximated by a polygon and roads on a map, and FIG. 8 is a diagram showing an example of candidate line segments on a map selected for a line segment of the traveling locus. . 1 ... Distance sensor, 2 ... Direction sensor, 3 ... Signal processing device, 4 ... Running track storage device, 5 ... Map information storage medium, 6 ... Storage medium reproducing device, 7 ... Display device, 8 ......
Operating device

Claims (1)

(57) [Claims] 1. The present position of a moving body on a two-dimensional coordinate corresponding to a road map projected on a screen with map data relating to the position of the road on the two-dimensional coordinate is detected while detecting a traveling distance and a traveling direction of the moving body. In a travel route display device that sequentially obtains the current position of a moving body on the road map by calculation processing and stores the current position data that changes with the traveling of the moving body in a memory. Means for approximating the traveling locus and the road on the map into polygons by line segments based on the traveling locus data and the map data obtained by the method, and the traveling locus approximated to the polygon and the road on the map. Means for matching each pattern of using the relaxation method,
And a means for correcting the current position of the moving body so that the traveling locus is on the road of the line segment where the matching is obtained.