JPH0251014A - Navigation apparatus of present position calculation system - Google Patents

Abstract

PURPOSE:To perform the guidance of the admission road to one's destination at any crossing without fixing a course by calculating the present position by setting the distance from the admission road at a crossing to the terminal crossing of said road as a unit. CONSTITUTION:A plurality of processing modules performing processing necessary for navigation are provided to a navigation processing part 4. When the present position is inputted from an input part 1, the processing part 4 calculates the present position from road system data 6 relating to the road concerned, the data of a distance sensor 2 and the data of a steering angle sensor 3. Further, the residual distance up to a final crossing and the position of said crossing are calculated using a plurality of the sub-modules possessed by a present position tracking module 17. Further, the road of an advance direction is selected at said crossing from the data 6 and the present position is calculated even on said road in the same way. This operation is repeated at every crossing and the guidance of the advance direction to one's destination at every crossing is performed by the display or sound output device of an output part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a navigation device using a current position calculation method, which calculates the current position for each intersection and provides course guidance to the destination by inputting the destination.

[Conventional technology]

2. Description of the Related Art Navigation devices provide route guidance to destinations for drivers who are unfamiliar with geography, and navigation devices have been actively developed in recent years.

Conventional navigation devices set a course from the starting point to the destination by inputting the starting point and destination in advance before traveling, and perform navigation according to the set course.

In navigation, when specifying a course, a map is displayed on the CRT screen and the course is displayed overlaid on top of it.
Additionally, as information about the next intersection to turn on according to a preset course, the distance to the next intersection is displayed using numbers, graphs, and characteristic photographs, and it also uses audio output. There is also.

[Problem that the invention seeks to solve]

However, conventional navigation devices set a course from a departure point to a destination as described above, and provide course guidance according to the set course. Therefore, if you make a mistake in judging an intersection, etc. and deviate from the course, you must either return to the set course or set a new course using that location as the starting point, or you will continue to drive according to the guidance of the navigation device. The problem is that it can't be done. However, returning to a set course and setting a course using that position as a starting point place a very heavy burden on the driver. In other words, needing course guidance means that you are not familiar with the road conditions in the area, and if you get lost in such an unknown area, you may not be able to find your starting point or destination, but you may not be able to find your current location. This is because it is difficult to even recognize it.

In addition, whether or not you have passed through a predetermined intersection according to the course guidance is based on the premise that distance sensors and steering angle sensors are used to detect travel distance, right turns, left turns, etc.; however, in reality, these detection errors may occur. There is also the problem that there is a problem in that it is accumulated and leads to errors in judgment. In other words, a course is set from the departure point to the destination, and the distance traveled, right turns, left turns, etc. are detected according to that course, so distance errors are accumulated.
The correction becomes impossible.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide a navigation device using a current position calculation method that can guide the road to a destination at any intersection without fixing the course. That is.

[Means for solving problems]

To this end, the current position calculation type navigation device of the present invention includes road network data having linkage information and coordinate information regarding intersections and roads between intersections, travel distance detection means, steering angle detection means, travel distance, steering angle, and road network data. It is characterized by comprising a current position calculation means for calculating the current position from the data, calculating the current position in units of units from the road on which you are traveling at the intersection to the end point intersection of the road, and further, reaching the destination at each intersection. The present invention is equipped with a means for generating traveling direction data and a guidance output means, and generates traveling direction data by inputting a destination, and uses a current position calculating means to select a traveling road for each intersection and specify the current position. , is characterized in that it outputs guidance on the direction of travel of the terminal intersection on the current road.

[Action and effect of invention]

In the navigation device using the current position calculation method of the present invention,
When the current location is input, the current location is calculated from the road data, travel distance, and steering angle.

Similarly, at the end intersection of a road, the road in the traveling direction is selected from the road network data, and the current position is calculated for the next road as well. Therefore, by having the traveling direction data for reaching the destination at each intersection, the current position is calculated repeatedly at each intersection, unless the course is fixed and the destination is changed, and the current position is calculated repeatedly at each intersection until the destination is reached. Guidance on the direction of travel is provided.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram showing the system configuration of an embodiment of a navigation device using a current position calculation method according to the present invention.

In FIG. 1, an input unit 1 is comprised of input means using hard keys, touch input means from a display screen, etc., and is used for inputting a destination, current position, start input, etc. The distance sensor 2 is for detecting the travel distance of the vehicle, and the steering angle sensor 3 is for detecting the steering angle of the operated vehicle. The output unit 5 includes a display, an audio output device, etc., and displays a menu necessary for inputting a destination or current position, and outputs course guide information. Road network data 5
consists of data such as information on intersections, roads that connect intersections, and node strings that make up the roads. The navigation data 7 consists of course guide information, set course information, and other data necessary for navigation, and stores the navigation data generated by the navigation processing section 4. The flag table 8 is a table in which flags necessary for navigation are registered, and is accessed by the navigation processing unit 4 depending on the processing situation and updated as appropriate. The navigation processing unit 4 is configured by a computer, for example, and stores road network data 6, navigation data 7, and a flag table 8.
, and processes data and information input from the input section 1 and detection signals from the distance sensor 2 and steering angle sensor 3.

The navigation processing unit 4 is an input data processing module 1 that analyzes and processes data and information input from the input unit 1.
1. It has a distance data processing module 12 that processes the detection signal of the distance sensor 2, and a steering angle data processing module 13 that processes the detection signal of the steering angle sensor 3, and also processes the data and information input from these processing units. It has a plurality of processing modules based on the base that perform the processing necessary for navigation.

The processing control module 14 performs processing control of the entire navigation processing section 4 according to instruction information input from the input section 1, and refers to the flag table 8 as necessary to input the current position to the route search module 15. The module 1G controls the current position tracking module 17.

When a destination is input from the input unit 1, the route search module 15 searches for an optimal route to guide the user to the destination while accessing the road network data 6. The optimal direction of travel to the destination is set for all intersections in 6. The searched data is then stored in the navigation database. In this case, if we focus on an intersection, we will select a road and drive according to the direction of travel set at that intersection, and then select a road according to the direction of travel that has been set repeatedly at the next intersection, and then again at the next intersection. The settings are set so that you can arrive at your destination on the optimal route by driving along the route. Here, the meaning of "optimal" rather than "shortest" means that when searching for a route, considering the width of the road, the number of intersections passed, traffic volume, and other driving conditions, depending on the weighting of these factors, the absolute distance may not necessarily be the shortest. This is because it includes a search that is the shortest when converted into travel time.

When the current position is input from the input unit 1, the current position input module 16 recognizes the current position from the road network data 6 and the navigation data 7, and the corresponding intersection shape, direction, landmark, intersection name, road in the traveling direction, etc. Draw etc.
This is used to display data on the screen of the output unit 5 and to set data necessary for navigation. Then, necessary flags are set so that tracking of the current position is activated by the start input.

The current position tracking module 17 is activated when a route search is performed, navigation data is set, and the current position is input. This method detects intersections and repeatedly performs current position recognition processing for each intersection to track the current position. The state at that time is appropriately set as a flag in the flag table 8, and the transition to each processing step is determined by referring to this flag.7Therefore, the initial position setting 18, sensor detection I9, remaining distance calculation 20, bending point detection 21, road ;π slope 22, distance yi beach difference correction 23, and other sub-modules.

The remaining distance calculation 20 constantly calculates the remaining distance to the intersection in order to detect the current position using the intersection, and performs intersection recognition processing when the remaining distance to the intersection reaches a predetermined value. The bend point detection 21 performs intersection recognition processing, and detects a bend start point and a bend end point within an error range of an intersection to detect a bend point position corresponding to the intersection position. The road selection 22 is to detect the selected road by actually passing through the intersection, regardless of whether or not you have selected the guided road in the direction of travel. I try to provide guidance in the direction of travel. Then, the distance error correction 23 is performed based on the detected bending point position and the selected traveling road.
The current position on the traveling road is determined by correcting the distance/return difference. That is, here, the remaining distance to the terminal intersection on the current position road is determined.

In this way, by detecting your current position at an intersection and recognizing the road you are traveling on, even if you are given guidance regarding the end intersection of that road, you may not be able to proceed as directed at that intersection (but you may not be able to proceed according to the guidance). It is possible to provide guidance based on the roads that have been identified, and navigation continues.In other words, guidance on the direction of travel at each intersection is an intelligent guide,
The configuration allows navigation to continue even if the road is not the driving direction.

Next, the contents of processing by the navigation device having the current position calculation method according to the present invention will be explained in more detail. First, prior to explaining the processing contents, an example of a data structure prepared in a navigation device having a current position calculation method according to the present invention will be explained.

FIG. 3 is a diagram showing an example of a data structure of a road network, intersection data, road data, and node string data.

Now, for example, intersection numbers I~ as shown in Figure 3(a)
When there is a road network consisting of road numbers ■ and [phase], intersection data has a data structure as shown in jb) in the same figure, road data in (C) in the same figure, and node data in rd) in the same figure.

The intersection data includes the intersection number l as shown in the same figure (b).
Corresponding to ~ ■, at least the smallest road number among the roads where the intersection is the starting point, the smallest road number among the roads where the intersection is the end point, and the location of the intersection (east longitude, north latitude) , has information on intersection names.

In addition, as shown in Figure (C), the road data includes at least the next road number among roads that have the same starting point, the next road number among roads that have the same end point, and the intersection, corresponding to the road numbers ■ to ■. It has information such as start point, end point, node string pointer, and road length by number.

As is clear from the figure, the next road number among roads with the same starting point and the next road number among roads with the same ending point can be generated by searching for the same number from the starting point and ending point using the intersection number. Can be done. Furthermore, the road length can also be determined by integrating the position information of the next node string data.

As shown in the same figure ((sub)), the node string data includes the number of nodes at the beginning of the node string pointer of the road data, and then the node position (east longitude, north latitude) information for the node corresponding to that number. In other words, a node string is constructed for each road data.The illustrated example shows node strings for road numbers ■ and ■.

As is clear from the above data structure, the road number unit consists of a plurality of nodes. In other words, node string data is a collection of data related to one point on a road, and if the connection between nodes is called an arc, a road is expressed by connecting each of multiple node strings with an arc. . For example, regarding the road number ■, the node string data AOOO can be accessed from the node string pointer of the road data, and it can be recognized that the road number ■ consists of 15 nodes.

For example, when focusing on an intersection number ■, for a course that starts from this point, first, the road number ■ is determined from the information of the road where the intersection data appears, and then the next road data with the same starting point is Road number @ is searched from the information of "Road number".

Then, from similar information regarding the road number ■, the road number [
phase], followed by ■. Here, since the road number ■ is the first road number, it can be determined that there are no surrounding roads with other road numbers.

This also applies to the end point. In this way, by using the intersection data and road data, it is possible to search for the road number for entering and exiting each intersection, and also to find the distance of the route connecting each intersection. Furthermore, by adding driving conditions such as entry prohibition, right/left turn prohibition, road width, etc. to these data, the data can be used as information for extremely detailed route searching, which will be described later.

Next, the overall processing flow will be explained with reference to FIG.

FIG. 2 is a diagram for explaining the overall processing flow by the navigation device having the current position calculation method according to the present invention, and FIG. 4 is a diagram showing an example of both sides of the menu for inputting a destination.
FIG. 5 is a diagram for explaining an example of route search output, and FIG. 6 is a diagram showing an example of guidance output.

(Sl) First, input the destination. The destination can be determined by displaying both sides of the menu as shown in Figure 4, for example.
Enter the destination code (roool) using the numerical value on the numeric keypad.
J) is input by touch.

(S2) Next, a route search mode is entered, and the optimal route direction to the destination is set for each intersection. For example, in Figure 3 (a
In the road network shown in ), if the intersection (2) is the destination, the direction of travel to the destination is set for each of the intersections (a) to (2) as shown in FIG. 5(a). An example of the data is shown in FIG. 2(b). This route search is
The direction of travel for each intersection is set by sequentially determining, for example, the direction that is the shortest distance to the destination, starting from the intersection closest to the destination.

(S3) Enter the current location as the starting point. A detailed explanation will be given later with reference to FIG. 7, but in this process, the "current position tracking failure flag", "destination guidance flag", etc. are turned off.

(S4) When the current position is inputted, guidance in the traveling direction at that position becomes possible, and the current position is tracked by processing the signals from the distance sensor and the steering angle sensor as the vehicle travels. A detailed explanation will be given later with reference to FIG. 8, but in this process, the "intersection arrival flag" is turned off at an early stage, and information such as the length of the current road, the end intersection, the node string, etc. is recognized, and the current location is recognized. When the guided intersection is reached, the "intersection arrival flag" is turned on, and when the guided intersection cannot be detected, the "current position tracking failure flag" is turned on. Make it.

(S5) After the current position tracking process, it is checked whether the "intersection arrival flag" is on or off.

(S6) If the "intersection arrival flag" is off, it is further checked whether the "current position tracking failure flag J" is on or off, and if the "current position tracking failure flag" is off, the Since it can be determined that the vehicle is traveling on a road, the process returns to step S4 to continue tracking the current location, but if the "current location tracking failure flag" is on, the vehicle is traveling on a road other than the road in the road network data. It is determined that the current location is the starting point, and the process returns to step S3 to input the current location as the starting point again.

(S7) If the "r intersection arrival flag" is on, it is then checked whether the "destination guidance flag" is on. The "destination guidance flag" is turned on when the terminal intersection of the current location road becomes the destination intersection in processing step SIO, which will be described later. If this "destination guidance flag" is on, it means that the guidance to the destination intersection has ended and the process returns to the initial destination input process.

(3B) However, if the "destination guidance flag" remains off, the destination intersection is further ahead of the next intersection, so proceed to the end intersection of the current location road. Intersection guidance is provided by reading the direction data, drawing the intersection shape, intersection characteristics, landmarks, direction of travel at the intersection, etc. on the screen, and displaying the intersection name and remaining distance to the intersection, as shown in Figure 6. Output. At this time, the "intersection reached n flag" is also turned off.

(S9) Then, it is checked whether the terminal intersection of the current position road is the destination intersection. If it is not the destination intersection, the process returns to step S4 to track the current position.

(SIO) If the terminal intersection of the current location road is the destination intersection, the "destination guidance flag" is turned on and the process returns to the current location tracking in step S4.

The above is the overall process flow.

Next, the main processing routine of the above steps will be explained in more detail.

FIG. 7 is a diagram showing a processing routine for inputting the current position.

In the processing routine of current location input S3, first, when an intersection number is input, the intersection direction, intersection shape, intersection name, intersection landmark, etc. are recognized from the intersection data, road data, and node string data described above. As shown in Figure 7 (a), the intersection name, intersection characteristics, and direction of travel are drawn on both sides.
Display (S31, 332), and store the traveling direction data at the intersection number input based on the traveling direction data shown in FIG. 5 etc. as the road number of the current position road, and display the traveling direction road as An arrow is drawn as shown in (a) (S33.534). After that, wait until there is a start input, and when Driving Sweat inputs a start input when passing an intersection, turn on the "current position tracking processing flag" and
[Current position tracking failure flag], [Destination guidance flag],
Turn off each “intersection arrival flag” (S35,
336).

FIG. 8 is a diagram showing an example of the processing routine for current position 1 tracking, FIG. 9 is a diagram showing an example of the processing routine for initial position setting,
Figure 0 is a diagram showing an example of a processing routine for sensor detection.
Figure 12 is a diagram showing an example of a processing routine for calculating remaining distance, Figure 12 is a diagram for explaining calculation processing of vehicle heading and trajectory, Figure 13 is a diagram showing an example of a processing routine for detecting a bending point,
Figure 4 is a diagram showing an example of a processing routine for road selection;
The figure shows an example of the processing routine for distance #l error correction.
FIG. 6 is a diagram for explaining the contents of the process of correcting the dealer error.

As shown in FIG. 8, the current position tracking processing routine (5411) first checks whether the current position tracking initialization flag J is on. , is on if initial data for tracking the current position has not been set, so the initial position setting shown in FIG. 9 is performed.

Once this setting is made, the "current position tracking initialization flag" is turned off, so the process directly proceeds to the next step.

In the initial position setting, as shown in Figure 9, the road length, end point intersection, and node string are read from the road data and node string data according to the "road number of the road at the current location." ”, “Terminal intersection of current location road”, and “Node string of current location road”. Furthermore, read the distance sensor signal and set its value to [current distance sensor value J]. Then, turn off the "current position tracking initialization flag", "inside error range flag", "error range passing flag", "waiting for bending end flag", "bending point detection flag", "bending detecting flag", etc. and set "Current position road length" to "Remaining distance to intersection".

(3412) Next, the sensor detection process shown in FIG. 10 is performed. In this process, first, the current sensor values are set as the previous sensor values for distance and steering angle, and then,
Read the sensor value and use it as the current sensor value. and,
The amount of change in the steering angle corresponding to the distance traveled is determined, and the steering angle Sta at the current position is determined.

(S413) After setting the loop counter i to 0, the remaining distance calculation and subsequent processes are repeated while incrementing the loop counter i until the distance reached by the loop counter i is reached.

In the remaining distance calculation, as shown in FIG. 11(b), the remaining distance from the current position to the final intersection is stored as current position information with respect to the road number of the current position road and the final intersection number. Then, the distance traveled is subtracted from the remaining distance to the intersection in accordance with the pulse input from the distance sensor every time the vehicle travels a unit distance, and the value of the remaining distance is updated. As shown in Figure (a), this remaining distance is judged as whether it is within the intersection error range distance or not. " and repeat the remaining distance calculation.

If the remaining distance to the intersection falls within the intersection error range distance, "
Turn on the “Within Error Range Flag”. If the intersection error range distance is exceeded after turning on the "error range flag", the "error range passage flag" is turned on.

(S414) When the “rfi difference within range flag” is turned on,
The vehicle direction and trajectory are calculated and the bending point shown in FIG. 13 is detected.

To calculate the vehicle heading and trajectory, as shown in Fig. 12, the traveling distance and steering angle Sta are sampled every time a certain distance #d is traveled, and a new vehicle heading is calculated from the previous vehicle heading Ang and trajectory (x, y). and the trajectory are calculated and stored in memory. For example, the vehicle direction Ang (i) is calculated from the steering angle Sta (1) read from the sensor at fixed distance intervals and the vehicle rotation angle θ (st) with respect to the steering angle stored in advance.
g (+) = θ (5ta (1) ) + A n g (
+-1) Also, the vehicle trajectory (X (i), Y (i)
) is (X (+), Y (i) ) - (X (i-1) +d x, Y (+-1) +d
)') d x=d Xcoq(x-An g(i) )
It can be determined using the formula: d y=dXsin(π-Ang(i)).

In addition, in bending point detection, <542
1> First, it is determined whether the "bending end wait flag" and "bending detection in progress flag" are both off and the steering angle is greater than the darkness value, and if YES (it has started to turn), "
"Bending start point" to the current distance ("Previous distance sensor value" + i
) and turn on the bending detection flag 1.In other words, the steering angle becomes larger than the dark value for the first time, so the bending detection processing state is set to 6°.However, if No (bending detection,
Or, if the steering angle is less than 1a and the steering wheel is running in a straight line, select <3422) IN to determine whether the "bending detection flag" is on and the steering angle is smaller than the r4 value, and then select YES. In the case of (a bend was detected last time and the surface turned off this time), the rotation angle is set to the difference between the current orientation and the orientation at the bend start point. Then, it is checked whether the rotation angle is greater than the minimum detected rotation error, and if the rotation angle is less than the minimum detected rotation error, it cannot be determined that the intersection has been turned, so the "bending detection flag" is turned off, but the If the angle is larger than the minimum detected rotation error, it can be determined that the intersection has been turned, so at this point, turn off the "Bending point detection in progress" and turn on the "Bending end wait flag" to set the "Bending end waiting position RJ to the current Set to distance. This is used to calculate the bending point position. Also, if NO (bending completed, still detecting bending, or running straight), (S423>Furthermore, Wait Flag" is on, determine whether ("Bending point end waiting position iFf" + 10 m) is smaller than the current distance, and if YES (traveled 10 m from the end of the bend), change the rotation angle to the current distance. Set to the difference between the azimuth and the azimuth at the bending start point.Then, it is checked whether the rotation angle is greater than the minimum detected rotation error, and if the rotation angle is less than the minimum detected rotation error, the ``bending point end wait flag'' is set. ", but if the rotation angle is greater than 20 degrees, turn on the "Bend point detection flag", turn off the "Bend end wait flag", set the "Bend end point" to the current distance, and calculate the position to the bend. conduct.

(S415) It is checked whether or not the "r bend 1-leg detection flag" is on, and if it is off, the counter i is incremented and the same process is repeated, but if it is on, a road is selected.

Also, once the intersection is within the error range distance, the "inside error range flag" is turned on, but the bending point is not detected and the "bend point detection flag" remains off, leaving the intersection outside the error range distance. Then, as previously explained in 3413, the "error range flag" is turned off and the "error range passing flag" is turned on. This includes the case where the vehicle passes through an intersection without turning, so the next road is selected in the same way in this case as well.

In selecting a road, first, the bending angle of the vehicle is calculated by 31, as shown in FIG. Then, the road exiting from the intersection is read, the bending angle of each connecting road is calculated, and the value that minimizes the difference between the connecting road bending angle and the vehicle bending angle is determined. If the minimum value is smaller than the predetermined maximum allowable angular difference, that road number is set as the "road number of the current location road", and the minimum value is greater than or equal to the predetermined maximum allowable angular difference. In this case, it is determined that the corresponding road was not detected, and the [Current position tracking failure flag] is turned on. In other words, the road closest to the bending angle of the vehicle is selected as the traveling road among all connected roads, but if the error between them is large, the current position is determined to be unable to be calculated and the current position is reset. ing.

(S416) Check whether the current position tracking failure flag is on or not. If it is on, step S in Figure 2
5. Return from S6 to 33, and if it remains off, continue with distance j! 1ffi difference correction.

In the distance M error correction, as shown in Fig. 15, first, as in the case of initial position setting, the road length, end point intersection, and node string are converted into road data and node string data according to the "road number of the current position road." Read these from rF17, the length of the road where you are located, "the end point intersection of the road where you are currently located", and "
Set in the node string J of the current position road. U7 said, ``
Check whether the "bending point detection flag" is on or not, and check the current distance # (
Find the difference between the "previous distance sensor value" + i) and the bending point position, subtract this value from the "current position road length", and set the result to "remaining distance to intersection/ki". . In other words, here we turn at the intersection and enter the next road,
In particular, a process is being carried out to correct the previous errors by adjusting the length of the new road. However, if "bending point detection) 1 is off," the "remaining distance to the intersection" plus the "length J of the road at the current location is updated as the new [remaining distance to the intersection mJ. .Kone is a process that corresponds to passing through an intersection without turning.For example, if the "remaining distance to the intersection" at that intersection is 0, the "current position road length" will be changed to the new " Remaining distance to intersection
It will be set as .

FIG. 16 shows the results of error correction when a bending point is detected and when it is not detected. If the difference in distance between the bending point position and the intersection position is ed as shown in (a) of the same figure, then the remaining distance to the next intersection with the bending point position as the intersection position is calculated as shown in Φ) of the same figure. On the other hand, correction of D is performed.

(S417) Turn on the "r intersection arrival flag", increment the loop counter i, and repeat the same process.

Next, the calculation process for bending points at intersections will be explained.

FIG. 17 is a diagram showing an example of a processing routine for calculating a bending position;
Fig. 18 is a diagram for explaining processing information for selecting a road, Fig. 19 is a diagram showing an example of a processing routine for calculating a vehicle bending angle, and Fig. 20 is a diagram showing an example of a processing routine for reading a road exiting from an intersection. 21 is a diagram showing an example of a processing routine for calculating a connecting road bending angle, and FIG. 22 is a diagram for explaining how to calculate the connecting road bending angle.

In the bending point position calculation process in the bending point detection process (FIG. 13), the intermediate distance B between the bending start point A and the bending end point C is determined as shown in FIG. , and the intermediate force position d of both cars (ff, kg), set the loop counter j to 1, and set B to the average distance ff
l B, and the vehicle direction Ang at distance IB.
(B), and then increment the loop counter j. Vehicle position Ang when ±J is set to B
For (B), search for a point that coincides with the intermediate direction d, and set -several points B as the bending point position. Then, the bending start point A
The distance from the bending point position iB to the bending point position iB is 0, and the distance D4° and 6 from the bending point position B to the bending end point C are determined. FIG. 18 shows these relationships.

As shown in Fig. 18, [Once the vehicle enters the intersection error range, selects the road it is traveling on, and calculates the bending point position and the next bending angle based on the vehicle direction and trajectory until it exits that range. There is. Assuming that the bending angle between the approach road (entering road) and the proceeding road (exiting road) at the intersection is as shown in the data shown in Figure (b), light rain normally occurs as shown in Figure (C).
), and the steering angle changes as shown in (d) of the figure. Therefore, the bending start point A and the bending end point C are the first
As shown in Fig. 8(d), when the steering angle exceeds the darkness value, that point is detected as the bending start point A, and when the steering angle returns to within the darkness value, that point is set as the bending end waiting position C'. Further, a point traveled by 10 m from that point is detected as the bending end point C.

In addition, in the process of calculating the vehicle bending angle in the road selection process (Fig. 14), as shown in Fig. 19, it is checked whether the "bending point detection flag" is off or not, and if it is on, the bending point is terminated. The point, bending point position, and bending start point are each determined by the bending point detection process (Figure 13), but if it is off, these values are not determined, so the following values are set. Ru. In other words, the current distance N (previous distance sensor value, ++i) is placed at the bend end point, the value obtained by subtracting the intersection error range distance from the current distance is placed at the bend point position, and the intersection error is calculated from the current distance at the bend start point. The value is obtained by subtracting twice the range distance.Then, /ABC shown in FIG. 18 is determined from the coordinates of these three points as the vehicle bending angle.

When the vehicle bending angle meter ℃ is completed, the next step is to read the road exiting from the intersection. In this process, as shown in Figure 20, the road number of the terminal intersection of the current position road is first read from the intersection data, and then the road number is read from the intersection data. Enter the road number [
Set "road number" and "first road number". Then, the loop counter j is set to 0 L7. Next, all the road numbers are read out by incrementing the loop counter j and sequentially reading out the road data from the road data until the next road number with the same starting point becomes the "first road number", and the number is calculated as the "number of roads exiting". ”.

In the road selection process (Fig. 14) and the process of calculating the connected road bend angle, as shown in Fig. 21, first the node string of the road number of the current position road is calculated from the road data and the node string data. Read, distance 1ffiID from the end point,
, nohehe city f! ! Calculate J(XA, )'A). Then, set the end point B of the example node to locus 1 (XA)7. )
The note string of the road exiting from the 9th order C2, difference is read from the road data and the node string data, and the coordinates (xay,) of a point C at a distance D4°, n from the starting point are calculated. Furthermore, from these coordinates, points A' and C' on the circles that are on the straight lines AB, BC, and h and inscribed in these straight lines are expressed as arcs (
A'C') length is Dup+D. Assuming an inscribed circle such that , , , calculate the coordinates of points A' and C', and set the intersection of the inscribed circle and the straight line that bisects IA B C to point B'
Find it as.

As a result, ZA'B'C' is set as the "connecting road bending angle". The 22nd chapter shows these relationships.
It is a diagram.

As described above, the current position calculation type navigation device according to the present invention uses various flags to process information, and the main ones are summarized as follows.

"Intersection Arrival Flag ÷"; When on, guidance for the next intersection is output. It is turned off during current position input processing and turned on when passing through an intersection.

"Destination guidance flag": If it is on when you arrive at an intersection, it is judged that you have arrived at the destination and returns the main routine to the beginning (destination pickup processing).It is turned off when processing the current position input, and the flag is turned off when the current position is input. Turn on if the next intersection is the destination when outputting guidance.

"Current position tracking failure flag": If it is on, the current position tracking process returns and the main routine branches to input the current position again.It is turned off during the current position input process, and it is set when selecting a road. When, you should choose jn
Turn on when there is no road.

"Current position tracking processing flag": When on, it calls the initial position setting routine, and is turned off when setting the initial position and turned on when inputting the current position.

[Within error range] Ug J: If on, calculate the trajectory,
It detects bending points, etc., and turns it on if it is within the intersection error range, and turns it off otherwise.

"Error range passing flag"; When on, the road is selected; if the intersection passes through the error range, it is turned on; otherwise, it is turned off.

"Bending point detection flag": When on, the road is selected by tracking the current position, and the current position is reset by distance error correction, and when it is off, the bending start point and bending point are determined by calculating the vehicle bending angle. This is used to set the end point and bending point position. It is turned off when setting the initial position, turned on when the bending point is detected, and turned off after correcting the distance error.

“Bending detection flag” and “Bending completion wait flag”;
This is used to detect bending and the end point of bending, and is turned off when setting the initial position. The ``bending detection flag J'' is turned on when the steering angle exceeds a threshold value, and its on/off is controlled depending on whether the rotation angle exceeds the minimum detected rotation angle.

Next, another embodiment of the present invention will be described.

FIG. 23 is a diagram showing an example of a processing routine for tracking the current position in another embodiment of the navigation device having the current position calculation method according to the present invention, and FIG. 24 is a diagram for explaining bending point detection. .

In the above embodiment, the current position is tracked based on the road number and the remaining distance from the end point intersection of that road number.
In the embodiment shown in FIG. 23, intersections are recognized by coordinates and current positions are tracked. Therefore, in the process of tracking the current position, the process up to bending point detection is the same as the above embodiment, but instead of the process from road selection to distance error correction performed in the above embodiment, the process when passing an intersection is performed. It is designed to perform intersection approach direction, bending angle comparison processing, and current position correction processing.

According to the example shown in Fig. 24, when entering a circle with a certain radius from an intersection, it is recognized that it is within the error range of the intersection. Assuming that the distance is r, when the coordinates (xo, yo) of the current position (vehicle position) reach a position that satisfies the condition of (xc - IO)" + (yc-yo)!<r", as shown in Fig. 23 ( Suppose that the vehicle enters the circle shown in a). Then, as shown in FIG. 6(b), bending is detected to detect the bending start position and bending end position, and the orientations of these positions are set to -20' and -1, respectively.
When set to 00', trajectory bending accuracy - (bending end position azimuth) - (bending start position azimuth) 100
Determine °-(-200)=-80' and further detect the bending point position, D, = 1 bending point position - bending start position. □=1 bending end position - bending point position.

Fig. 25 is a diagram for explaining intersection approach direction and bending angle comparison processing, Fig. 26 is a diagram showing an example of a processing routine corresponding to the processing in Fig. 25, and Fig. 27 is processing for reading a road entering an intersection. FIG. 28 is a diagram showing an example of a routine. FIG. 28 is a diagram for executing the current position correction process. FIG. 29 is a diagram showing an example of a processing routine corresponding to the process of FIG. 28.

In the intersection approach direction and bending angle comparison process, Fig. 25 (a
), the road that enters the intersection number ■ is read from the road that contains the intersection data and the road that has the same end point of the road data, and the direction when entering from these roads is calculated from the intersection point position on the node string with respect to the road. It is determined as the direction of the position of DMp. For example, if the directions are as shown in Figure 24), then in the example shown in Figure 24), the road number [phase] whose approach direction is closest to the bending start position direction (-20°). is the approach road.

Once the approach road is determined, the road exiting from the intersection number ■ and the road having the same starting point are read from the road data, and the change in orientation when proceeding to these roads from the approach road [phase] is determined. In this process, it is determined as a change in the azimuth at a position D4° from the intersection position on the node row of the exiting road and the bending start position azimuth on the approach road. Therefore, when looking at the relationship between the approach road [phase] and the winter mountain road ■, ■, ■, ■. Therefore, in the example shown in Fig. 24 Φ),
Since the trajectory bending angle is −80°, the road [phase]→■ with the bending angle closest to this is determined as the traveling direction.

FIG. 26 shows the processing routine for comparing the intersection approach direction and bending angle. In the processing routine shown in FIG. 26, first, processing is performed to read the road entering the intersection.

In this process, as shown in Fig. 27, the road number of the terminal intersection of the current position road is read from the intersection data,
These numbers are called "road number" and "first road number" respectively.
Set to . Then, the loop counter j is set to O and the next road number with the same end point is determined from the road data while incrementing the loop counter j.
By sequentially reading out all the road numbers until reaching the ``first road number'', the number is calculated as ``the number of roads to enter''.
Set to . That is, the process corresponding to the process of reading the road number exiting from the intersection described above with reference to FIG. 20 is performed.

Similarly, the process of reading the road number exiting from the intersection described in FIG. 20 is performed, and the loop counter j is set to O.

First, while incrementing the loop counter j up to the number of roads entering, determine the approach road shown in the 25th round, read it, set the loop counter k to 0, and incrementing it up to the number of roads exiting the bend. The angle is calculated to determine the traveling direction road shown in FIG. 25(C).

Then, the road in the traveling direction obtained here is set as the road number of the current position road.

The current position correction is performed after finding the road number of the road where the current position is written. In this process, the current position coordinates are set as the bend end coordinates on the node string of road ■, as shown in Fig. 28 (a). , the current position direction is the bending end position direction (-120') on the node string. Then, as shown in Figure 0)), the terminal intersection V of road number ■ is read out from the road data as the next intersection, the coordinates of this intersection are read out from the intersection data, and the vehicle enters within the error range of this intersection ■. to monitor.

The 29th section shows the processing routine for correcting the current position above.
It is a diagram. In the processing routine shown in FIG. 29, first, the end point intersection and node string of the road number of the current location road are read from the road data, and these are defined as the "end point intersection of the current location road" and the "node string", respectively.

In addition, the east longitude and north latitude coordinates of the "end intersection of the current road location" are read from the intersection data and set as the "east longitude and north latitude coordinates of the Seibun difference point."

Then, change the coordinates on the node string at a distance of D from the start point of the node string J to the coordinates of the current position (X [r previous distance sensor value) + i), Y ('previous distance sensor value J + )year,
The azimuth between nodes at a distance of D4°w7 from the starting point of the "node string" is defined as the azimuth of the current position.

Note that the present invention is not limited to the above-described embodiments, and various modifications are possible.

In addition, in the above example, the intersection was used as the guide point, but if the distance between the two intersections is long, characteristic features such as bridges, guards, public facilities, etc. in between may be set as the guide point. . Use the characteristic absolute information at that point as information to get to your destination, and display maps and photos on the screen.
It may be configured to output this information as well as audio. In this case, if there is content that particularly calls attention to the output information, the display mode or display attributes of that part may be changed, or a different tone color, intermittent sound, etc. may be used. Furthermore, in addition to sequentially moving through the guidance points using a trigger, the user may be able to view guidance information from several points of light from the current location as appropriate.

For example, for a district with a monotonous road such as a single road and a district with a complicated road, the 1-vigation system having the current position ff1W output method described above and the update method using the above-mentioned switch operation etc. are combined. It's okay.

As is clear from the above description, according to the present invention, the direction of travel to the destination is set for each intersection, and the direction of travel to the next intersection is guided by recognizing the current position at the intersection. You can freely choose the course to the ground. Furthermore, guidance on the direction of travel to the destination can be output at any intersection. In addition, based on the road network data, intersection recognition processing is performed on the condition that the terminal intersection is within the error range, the road in the direction of travel is selected, and guidance for the next terminal intersection is output, so it is possible to reach the destination without crossing the intersection. It is only necessary to repeat the course guidance for each intersection, and a simple data structure allows for flexible responses from any intersection. Even if you select a road that is different from the guided course, as long as the destination is not changed, you can be guided in the direction to the destination at the intersection at the end of that road.

Therefore, even if the user does not follow the optimal course due to road congestion or the like and selects another road that has an intersection, guidance to the destination can be obtained at the next intersection. Similarly, if you stray off course and get lost, you can drive appropriately to an intersection and input that intersection as your current location as 2, allowing you to immediately track your current location without having to search for a route. . Further, even if the road tracking means for recognizing intersections becomes unavailable, the driver can replace the intersection recognition signal with a trigger input using, for example, a touch switch or a button switch.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the system configuration of one embodiment of a navigation device using a current position calculation method according to the present invention, and FIG. 2 is a diagram for explaining the overall processing flow by the navigation device using a current position calculation method according to the present invention. Figure 3 is a diagram showing an example of the data structure of road network and intersection data, road data and node string data, Figure 4 is a diagram showing an example of a menu screen for inputting a destination, and Figure 5 is a diagram showing an example of the route 17 search. A diagram for explaining an example of output, FIG. 6 is a diagram showing an example of guidance output, FIG. 7 is a diagram showing a processing routine for inputting the current location, and FIG. 8 is a diagram showing an example of the processing routine for tracking the current location. , FIG. 9 is a diagram showing an example of a processing routine for initial position setting, FIG. 10 is a diagram showing an example of a processing routine for sensor detection, FIG. 1I is a diagram showing an example of a processing routine for calculating remaining distance, and FIG. 13 is a diagram showing an example of a processing routine for detecting a turning point, FIG. 14 is a diagram showing an example of a processing routine for selecting a road, and FIG. 16 is a diagram showing an example of a processing routine for distance error correction, and FIG. FIG. 17 is a diagram showing an example of a processing routine for calculating a bending position, FIG. 18 is a diagram for explaining processing information in road selection, and FIG. 19 is a diagram showing an example of a processing routine for calculating a vehicle bending angle. , Fig. 20 shows an example of a processing routine for reading a road exiting from an intersection, Fig. 21 shows an example of a processing routine for calculating a connecting road bending angle, and Fig. 22 explains how to calculate the connecting road bending angle. FIG. 23 is a diagram showing an example of a processing routine for tracking the current position in another embodiment of the navigation device using the current position calculation method according to the present invention, and FIG. 24 is a diagram for explaining bending point detection. , FIG. 25 is a diagram for explaining the intersection approach direction, ...I curve angle comparison process, FIG. 26 is a diagram showing an example of a processing routine corresponding to the process in FIG. 25, and FIG. A diagram showing an example of a processing routine for loading roads into
FIG. 28 is a diagram for explaining the current position r correction process,
FIG. 9 is a diagram showing an example of a processing routine corresponding to the processing of FIG. 28. DESCRIPTION OF SYMBOLS 1... Input part, 2... Distance sensor, 3... Rudder angle sensor, 4... Navigation processing part, 5... Output part, 6... Road network data, 7... Navigation Data, 8...Flag table, 14...Processing control module, 15...Route search module 1-16...Current position input module 1-17...Current II''L stomach tracking module .Applicant: Aisin ADA Co., Ltd. Kigai 1 Representative Patent Attorney Ryukichi Abe (4 others) Figure 1 Figure 2 Figure 1 □ Figure 3 (J) Standing,!, Tenik Figure 3 ( d) Input the joint B color and feel the milling problem. Fig. 6 Fig. 7 Fig. 9 Fig. 10 Fig. 12 Fig. 11 (a) (F)) Fig. 13 Fig. 15 C Fig. 18 Fig. 18 (a) Fig. 19 Fig. 20 Fig. 22 Fig. 21 Fig. 23 Fig. 25 Fig. 24 (b) Fig. 24 (c) Amphoteric membrane j also Fig. 25 (C) Ivy Figure 27 Figure 28 (a) (b)

Claims (1)

[Scope of Claims] (1) Road network data having connection information and coordinate information regarding roads between intersections, travel distance detection means, steering angle detection means, current position is determined from travel distance, steering angle, and road network data. What is claimed is: 1. A navigation device using a current position calculation method, comprising a current position calculation means for calculating the current position, and calculating the current position in units of units of distance from the road on which the vehicle is traveling at an intersection to the end point intersection of the road. (2) The current position calculation type navigation device according to claim 1, wherein the current position calculation means calculates the remaining distance to the terminal intersection as the current position from the road length and travel distance. (3) The navigation device using the current position calculation method according to claim 1, wherein the current position calculation means calculates the current position at an intersection by determining the vehicle direction and trajectory from the travel distance and steering angle. (4) Current position 2. The navigation device according to claim 1, wherein the calculating means detects a bending point and calculates the current position based on a correspondence between the bending point position and a position determined from road network data. (5) It has a means for generating traveling direction data to reach the destination at each intersection and a guidance output means, generates traveling direction data by inputting the destination, and uses the current position calculating means for each intersection. 2. The navigation device according to claim 1, wherein the current position is determined by selecting the road on which the vehicle is traveling, and outputs guidance on the direction of travel to a terminal intersection on the current road.