JPS61243318A - Running path display - Google Patents

Abstract

PURPOSE:To continuously prevent the running locus of a vehicle from getting out of a road or the like on a map by dividing each of the patterns of the road on the map ad the running locus of the vehicle into segments on which a pattern recognition is performed, thereby matching the locus to the road. CONSTITUTION:In a signal processor 3, the patterns of a road on a map and the running locus of a vehicle are divided into segments, on which a pattern recognition is performed based on a polygonal approximation. In accordance with the segments of the road matched by means of the pattern recognition, the running locus is displayed on a display 7. Thus, a pilot mark M1 representing the present position of an automobile, a pilot mark M2 representing the proceeding direction of the automobile in said present position and a pilot mark M3 representing a running locus from a starting point to said present position are simulatively displayed on the map represented on the screen of the display 7 while following up the running condition of the automobile.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a travel route display device for displaying the current position and travel trajectory of a moving object such as an automobile on a screen on which a map is set in advance.

Lately, as I will explain in detail later, 1. For example, when driving in unfamiliar areas, vehicles, etc. As the vehicle travels, the distance detector detects the traveling distance according to the vehicle speed, and the direction detector detects the direction of travel and its change. From these detected values, the current position of the vehicle on two-dimensional coordinates is determined. It is possible to allow the driver to confirm the current position by calculating it by sequential calculations and displaying the result in memory and displaying continuously changing point information on a display screen on which a road map is displayed in advance. A driving route display device has been developed that allows this.

However, in such a driving route display device, it is unavoidable that position errors occur due to factors such as the accuracy of each detection when detecting distance and direction according to the driving condition of the car, etc., and as the car etc. progresses, position errors occur. Therefore, as the errors accumulate, the current position and the driving trajectory up to that point deviate from the road on the map, making it impossible to determine which road on the map the vehicle is traveling on. 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 travel trajectory pattern of the vehicle. In other words, in order to find a road pattern that matches the trajectory pattern traveled by a vehicle, we select several routes that are likely to have been taken by the vehicle from a complex set of roads, and then evaluate the suitability of the pattern for each. The road with the best matching pattern is assumed to be the one the vehicle has passed through, and the vehicle's travel trajectory is superimposed and displayed on the corresponding road portion on the map.

However, if such a correction method is used, a large number of road patterns will be extracted when searching and extracting the route that a vehicle is thought to have taken in a map with complicated roads. It takes a lot of time to perform processing to match one pattern with the vehicle's travel trajectory pattern, and when the vehicle passes through a road that is not on the map, the pattern cannot be matched and the vehicle travels slowly. It becomes impossible to correct the trajectory.

1 blood The present invention has been made in consideration of the above points.

To provide a travel route display device that displays the travel trajectory of a vehicle on a map together with its current position while calculating the travel trajectory so that the travel trajectory does not deviate from roads on the map.

In order to achieve the objective, the present invention utilizes the relaxation method, which is one of the pattern recognition techniques, and divides each pattern of roads and vehicle travel trajectories on a map into line segments, and generates patterns by polygonal approximation. By performing the recognition, the two are matched, and a means is taken to display the travel trajectory in accordance with the line segment of the road where the matching is performed.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of the configuration of a driving route display device according to the present invention, and its basic configuration includes (1) a light intensity type, which outputs a pulse signal for each unit traveling distance according to the rotation of a car tire; A distance sensor 1 using a type or a mechanical contact type, and a direction sensor 2 that outputs a signal proportional to the amount of change in direction as the vehicle travels, which is composed of a gyroscope or the like that detects changes in angular velocity in one direction, for example.
The distance traveled by the vehicle is measured by counting the number of pulse signals from the distance sensor 1, and the change in the traveling direction is calculated according to the output signal from the direction sensor 2, thereby calculating the distance on two-dimensional coordinates for each unit distance traveled by the vehicle. A signal processing device 3 consisting of a CPU, a program ROM, a control RAM, etc., which determines the position of by sequential calculations and performs centralized control of the entire system, and two-dimensional coordinates that change every moment determined by the signal processing device 3. A driving trajectory memory device (RAM) 4 that sequentially stores the above position data and holds it as finite continuous position information corresponding to the current position of the car, and a plurality of map information stored in advance in file units. A map information storage medium 5, a storage medium playback device 6 that selectively reads necessary map files from the storage medium 5, and displays a map surface image on a screen according to the read map file, and Based on the position data stored in the trajectory storage device 4, the display device 7 displays the current location of the vehicle, the previous travel trajectory, the current direction of travel, etc. on the same screen in an updated manner every moment, and an operation command is sent to the signal processing device 3. In addition to specifying the selection of the map to be displayed on the display device 7 and setting the starting point of the vehicle on the displayed map, the direction of the displayed map and travel trajectory is changed, the display position is shifted, and the map is and an operating device 8 that can appropriately change the settings of the display format such as selection of the partial enlargement display 2 display scale of the travel trajectory.

With this configuration, the selectively read map is displayed on the screen of the display device 7, and the signal processing device 3 presets the map according to the vehicle travel from the starting point set on the map. The current position on the X-Y coordinates (xyy) according to the scale of the map
is determined by calculation every moment, and the calculation results are sequentially sent to the travel trajectory storage device 4 to update the storage contents, and the storage contents are constantly read out and sent to the display device 7. As a result, as shown in FIG. 2, the display device 7 displays a display mark Ml indicating the current position of the vehicle on the map displayed on the screen.

A display mark M2 indicating the direction of travel of the vehicle at the current position and a travel trajectory display mark M3 from the starting point S to the current position are displayed in a simulated manner following the traveling state of the vehicle.

The above configuration and operation are the same as the conventional travel route display device described at the beginning.

Therefore, in such a driving route display device, as shown in FIG. 3, due to the above-mentioned cumulative error, the current position and the driving trajectory up to that point gradually deviate from the road on the map as the car travels. Eventually, it becomes impossible to determine where on the map the car is currently traveling.

The present invention resides in such a driving route display device, and in particular, in the signal processing device 3, each pattern of roads and vehicle travel trajectories on a map is divided into line segments and pattern recognition is performed by polygonal approximation. and a means for displaying the traveling locus according to the line segments of the road matched by the pattern recognition.

FIG. 4 shows the processing procedure in the signal processing device 3 in that case. First, based on the traveling trajectory obtained as described above, it is divided into line segments and polygonal approximation is performed for each line segment. A list is created, and candidate line segments on the map that are likely to match each line segment of the travel trajectory are selected by making correspondence with the line segments listed after polygonal approximation of the roads on the map.

Next, pattern recognition between each candidate line segment on the selected map and each line segment on the travel trajectory is performed using the relaxation method, that is, the line segment currently being recognized while looking at the connections with the previously matched line segments. A matching index indicating the degree of correspondence between each line segment is determined by arithmetic processing, and it is updated with a matching coefficient. Here, the matching index is the probability that the line segments match, and pattern recognition is repeated until a 100% match is found among the selected candidate line segments on the map that correspond to the line segment of the travel trajectory. I will do it.

Finally, we take a set of line segments on the map that correspond 100% to each line segment of the driving trajectory, and display the set of line segments as the driving route of the vehicle! 7 to display the driving route along with the map.

As shown in Figure 5, the line segment list of the travel trajectory is as follows:
Line segment i of the travel trajectory approximated by a polygon (i=1 to m)
The coordinate position of the starting point [(Xsi, Ysi), slope θi
, the length Li, and the coordinate position of the end point (Xs i, Ye i).

For example, it is created as shown in Table 1 below.

Table 1 Also, as a list of road line segments on the map, as shown in Figure 6, road line segments approximated by polygons j (j = 1
-n) Coordinate position of the starting point (XsJ+YSJ) + slope θj, length L J r Coordinate position of the ending point (Xej, Ye
Take each piece of data in j) and add 1 along with the number of each line segment connected to the start point and end point of line segment j.
For example, it is created as shown in Table 2 below.

Table 2 In addition, as a specific method for selecting candidate line segments on the map corresponding to line segment i of the travel trajectory, the difference in slope between line segment i of the travel trajectory and line segment j on the map is calculated by dθ, and the length d is the difference between
L, the distance between the starting points is dS.

Let the distance between the end points be dE, and allowable values α1, . α2. α3. Using α4,
A line segment on the map that satisfies all of the conditions of formulas (1) to (4) below is selected as a candidate line segment.

dθ=1θi−θjl<β1...(1) dL
= l Li−Ljl<β2 (2) dS=
(Xsi7Xsj) ” + (Ysi-Ysj)
"<β3...(3) dE= (Xei-Xej)" +(Yei-Ye
j) ” <= a4 (4) Furthermore, if the matching index between the line segment i of the travel trajectory and the candidate line segment j on the map is Pi(j), it is obtained according to the following calculation formula.

First, how much the feature amount differs between the line segment of the travel trajectory and each candidate line segment is determined according to the following equation.

P'j(j)'' (1-ωlXmax(dθ-β1,
0)-ω2Xmax(dL-β2,0)-+113 X wax(dS-β3,0)-ω4X
max(dE-β4.O)) (5) where ωl to ω4 are the weights of each feature.

It changes depending on the degree of error of each sensor 1, 2 used in the travel route display device. Further, β1 to β4 are error ranges for minute differences in each feature amount.

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

Pi(j)=P'1(j)/PreP'i(j')
(6) In addition, the compatibility coefficient at the time of updating is calculated based on the connection relationship (angular difference, presence or absence of connection) between the starting point side and the ending point side of the line segment i of the traveling trajectory and the candidate line segment j on the map in Fig. 7. It shows how similar the connection relationships are between the starting point side and the ending point side, and the compatibility coefficient rik(j, Q) on the starting point side of line segment j with respect to line segment i is determined by the following equation.

1”1k(j, Q)=(1−ωrXmax(lθ
i-θkl-10j-OQJ-γ, 0))XD (7) The fitness coefficient riIIl(j, n) on the end point side is found in the same way.

Here, ωr is a weight for the adaptation coefficient, which changes depending on the degree of error of each sensor 1, 2 used in the travel route display device. Also, γ is the error range for the adaptation coefficient, and D is the connection coefficient, which is 1 if connected.
If not connected, the value is 0.

The matching index is updated by the following calculation process.・・・・(8) However, Qi(j)=, 1/2 [max (I”1k
(j, Q)・Pk(Q))+max (f'-'i!+
(j, n) ・P m(n) ) (9).

For example, as shown in Fig. 8, the traveling trajectory is divided into line segments a and b.
, c, ■, ■, ■ are selected as candidate line segments for line segment a, ■, ■, ■ are selected as candidate line segments for line segment S, and ■, ■, are selected as candidate line segments for line segment C. Let's consider the case where ■, ■, [phase] are selected A and B in Figure 0.

C indicates the travel section of the vehicle.

First, when the vehicle is in the section , first, the difference in slope of the line segment dθ
Candidate line segments are selected by using a and the distance dSa between the starting points as feature quantities, and then matching indices Pa(1), Pa(
2) and Pa(3) are calculated respectively. At that time, the candidate line segment with a matching index of 100% is set as the travel route.

Next, when the vehicle is in section B, 1. For line segment a, use the difference in slope dθa, the difference in length dLa, the distance between starting points dSa, and the distance between end points dEa as feature quantities. Select candidate line segments by
Matching index P' a (1) of ■ and ■ for each candidate line segment
, P' a(2), and P' a(3), respectively.

2. Select candidate line segments by using the difference in slope dθb of the line segment and the distance dSb between the starting points as feature quantities for the line segment , and select each candidate line segment (1), (2).

@Tsumaychin'1m number p” b(4), P' b(5)
, P' b(6), respectively.

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

P'' a(1)= rab(1,4) X P' b(
4) x P' a(1)=Qa(1) X P'
a(1) P' a(2)= rab(2,4) X P' b(
4) X PI'a(2) = Qa(2) X P'
a(2) r'ab(3,5) X P' b(5)
>r' ab(3,6) X P' b(6), then P" a(3)= r'ab(3,5) X P' b
(5) X P' a(3)” Qa(3) X P
' a(3) rab(1,4) X P ' b(1)
< r ab(2,4) X P' b(2), then P' b(4)= rab(2,4) X P' a(
2) X P' b(4) = Qb(4) x p b
(4) P' b(5) = rab(3,5) X P' a
(3) X P' b(5) = Qb(5) x P
'b(5)Plb(6)=r'ab(3,6)×
P' a(3) X P' b(6)= Qb(6)
X P' b (6) Furthermore, at this time, if a candidate line segment that 100% matches each line segment a and b cannot be obtained, a second update is performed.

P” a(1)= rab(1,4)X Plb(4)
X Pla(1)= r'ab(1,4) X Qb(
4) X P' b(4)X Qa(1) X P
'a(1)" (Qa(1)) "XQb(4)X
P'a(1)P" a(2)= rab(2,4)
X Plb (4) X Pla (2) = rab (2
,4) X Qb(4) X P' b(4)X Q
a(2) X P' a(2)= (Qa(2))
”XQb(4)X P' a(2)rab(3,5)
X P” b(5) > r”ab(3,6) X P
” When b(6), P” a(3)= rab(3,5) X Plb(5
) X P' a(3)= r' ab(3,5) X
Qb(5) X P' b(5)X Qa(3)
X P'a(3)"(Qa(3))" xQb
(s) x pHa(3) rab(1,4) X P”
When b (1) <r'ab (2, 4) X Plb (2), P'' b (4) = r'ab (2, 4) X P'' a
(2) X P' b(4) = I' ab(2,4)
X Qa(2) X P' a(2)X Qb(4
) X P' b(4)” (Qb(4))”
XQa(2)X P'b(4)P'' b(5)= r
'ab(3,5)X P' a(3)X Plb(5)
= r' ab, (3,5) X Qa(3) X P
'a(3)x Qb(5) x p' b(5) = (Qb(5))" XQa(3)X P' b(
5) P' b(6) = "ab(3,6)X P"
a(3)X Pl b(6)” r' ab(3,6)
X Qa(3) X P' a(3)x Qb(6
) x p' b(6) = (Qb(6)) ”XQa(3)X P'
b(6) Similarly, if a candidate line segment that matches each line segment a, b 100% cannot be obtained, updates are performed a third time, a fourth time, and so on.

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

Next, when the vehicle is in section C.

1. For line segment a, select candidate line segments by using the difference in slope dθa, the difference in length dLa, the distance between La, 1i d S a , and the distance between end points dEa as features. Matching index P' of ■,■ for each candidate line segment
Find a(1), P' a(2), and P' a(3), respectively.

2. Select candidate line segments by using the difference in slope dθb, the difference in length dLb, the distance between starting points dSb, and the distance between Sb and dEb as feature quantities for the line segment,
Matching index P' b (4) of each candidate line segment ■, ■, ■
, P' b(5), and P' b(6), respectively.

3. For line segment C, select candidate line segments by using the difference in slope of the line segment dθC2 and the distance between the starting points 1i d S c as a feature quantity, and each selected candidate line segment ■
, ■, ■, [phase] matching index P'c (7), P'
c(8), P' c(9), and P' c(10) are obtained, respectively.

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

P' a(1)= r'ab(1,4) X P'
b(4) X P' a(], )= Qa(1) X
P'a(1)P" a(2)= "ab(2,4
)X P' b(4)X P' a(2)=Qa(2
) X P' a(2) ``ab(3,5) X P
'b(5)>r'ab(3,6) X P' b(
6), P' a(3)= r'ab(3,5) X P' b
(5) X P' a(3) = Qa(3) X P
'a(3)I''ab(1,4) X P' a(1)
< r”ab(2,4) X P' a(2).

rbc(4,7) X P 1llc(7)<I”
When be(4,8) X P' c(8), P' b(4) = Qb(4) X P' b(
4) Here, Qb(4) = 1/2 (r ab(2,4)
P'a(2)+rbe(4,8)XP'
c(8)).

rbc(5,9) X P'c(9)< rbc(5
, 10)
'a(3)+r bc(5,9)XP'
c(9)).

Plc(7) = rbc(4,7) X P' b(4
) X P' c(7)= Qc(7) X P'
c(7)P' c(8)= r'bc(4,8)X P
'b(4)X P'c(8)'' Qc(8)X
P'c(8)Plc(9)"r'bc(5,9)
X P' b(5)X P'c(9)'= Qc(
9) X P' c(9)Plc(1,0)=rb
c(5,10) X P' b(5) X P', c
(10)=Qc(10)

P” a(1)= r”ab(1,4) X Plb(
4) X Pla(L)=r” ab(1,4)
Qb(4) X P' b(4)X Qa(1)
X P a(1) = (Qa(1)) ” XQb(4)X P' a(
1) P” a(2) = 1”ab(2,4) X P”
b(4) XPla(2)= r ab(2,4)
X Qb(4) X P' b(4)X Qa(2)
X P' a(2)=(Qa(2)) ”XQb
(4)XP' a(2)P2 a(3)= "ab(3
,5)X Pl b(5)X Pl a(3)= r
ab(3,5) X Qb(5) X P' b(
5)X Qa(3)X P' a(3)=(Q
a(3))” XQb(5)X P' a(3)P
2b(4) = Qb(4) X P 1b(4) where: Qb(4) = 1. / 2 (rab(2,4)
X P 1a(2)+ rbe(4,8) X P'
c(8)).

P ” b(5) = Qb(5) X P 1b(5
) Here, Qb(5)=1/2 (rab(3,5)
' b(3)+ r be(5,9) X P 1c(
9) ).

P'' c(7)= rbe(4,7) X P' b(
4) X P” c(7)= QC(7) X P”
c(7)P'' c(8)= r'bc(4,8)X
P' b(4)X P' c(8)=Qc(8)X
Plc(8) P” c(9)= rbc(5,9) X P” b(
5) X Plc (9) = Qc (9) X P 1c
(9) P2c(10)= rbc(5,10) X P' b
(5) X P' c(1,0)=Qc(10)
P ” c (10) Similarly, each line segment a, b, c
If a candidate line segment that 100% matches cannot be obtained, updates are performed a third time, a fourth time, and so on.

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

In this way, in the present invention, the travel trajectory of the vehicle and the road on the map are divided into line segments, each is approximated by a polygon, a list is created for each line segment, and the relaxation method is applied to each line segment according to the data in the list. Since pattern recognition is performed over the entire map, there is no need to select multiple roads on the map for pattern recognition based on travel trajectories, as was the case in the past, and pattern recognition can be performed quickly and reliably. Furthermore, as the distance traveled by a vehicle increases, the accuracy of pattern recognition based on line segment correspondence increases.

In addition, since line segments that are approximated by polygons are matched over the entire map, line segments of travel trajectories that cannot be matched are used as routes when the vehicle travels on roads that are not on the map. Be able to make decisions.

As described above, the driving route display device according to the present invention includes means for dividing each pattern of roads and vehicle travel trajectories on a map into line segments and performing pattern recognition by polygonal approximation, and the pattern. This system uses a means to display the driving trajectory according to the line segments of the road that are matched by recognition, so that the driving path is always displayed so that the driving path does not deviate from the roads on the map. It has the excellent advantage of being able to

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of a driving route display device according to the present invention, Fig. 2 is a diagram showing an example of display contents in the same embodiment, and Fig. 3 shows a state in which the driving trajectory deviates from the road. FIG. 4 is a flowchart showing the processing procedure of pattern recognition when carrying out the present invention, FIG. 5 is a diagram showing a traveling locus approximated to a polygon by line segments, and FIG. Diagram showing roads approximated on a mud map, No. 7
The figure shows the correspondence between a travel trajectory approximated by a polygon and a road on a map, and FIG. 8 is a diagram showing an example of candidate line segments on the map selected for the line segments of the travel trajectory. . 1...Distance sensor 2...Direction sensor 3...Signal processing device 4...Travel trajectory storage device! ! 5...Map information storage medium 6...Storage medium playback device 7...
Display device 8... Operating device

Claims (1)

[Claims] 1. The constantly changing current position of the moving body is determined by sequential calculations, and the current position of the moving body is updated and displayed on a screen on which a map is displayed in advance according to the data of the determined current position. In this system, each pattern of roads and vehicle travel trajectories on a map is divided into line segments and pattern recognition is performed by polygonal approximation, and matching is achieved by the pattern recognition. 1. A driving route display device characterized by having means for displaying a driving trajectory according to line segments of a road. 2. The travel route display device according to item 1 above, characterized in that parameters are calculated from the coordinate values of each line segment, and matching is performed using the parameters.