JPH01173816A - Navigation device for vehicle with current position calculating means - Google Patents

Abstract

PURPOSE:To improve a processing speed with simple constitution by comparing the angle of turning at a guide intersection or node in a course with a detected angle, and correcting a distance according to position data when the difference between the both is smaller than a specific value and calculating the current position. CONSTITUTION:When the current position and a destination are inputted from a input part 5, a course search part 13 reads out intersection data 19, node data 21, and path data 23 and stores them as search path data 25. A comparison and judgement part 11 compares the angle at the intersection or node on a searched path with the angle detected by a curve detection part 9 and judges that the vehicle turns at the intersection, etc., correctly when the difference between both of them is smaller than a prescribed value. Then, a guide processing part 15 corrects the distance according to intersection data, etc., to calculate the current position. Consequently, the current position is accurately calculated with the inexpensive constitution and the processing speed is increased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a device for navigating according to a predetermined route. The current position calculation means compares the detected actual bending angle, and if the difference is within a predetermined value, the current position is calculated by correcting the distance by assuming that the intersection or node at which the turn should be made has been turned. The present invention relates to a vehicle navigation device having the present invention.

[Conventional technology]

Conventionally, the current position calculation method of a vehicle navigation device uses a distance sensor that detects the traveling distance of the vehicle, a direction sensor such as a geomagnetic sensor or a gyro that detects the direction of travel of the vehicle,
It is equipped with a map storage device consisting of a video disk, videotape, CDROM, etc., and when necessary, map data of a specific area is read out from the map storage device and a map surface image is displayed. The position is displayed and the driver visually confirms the current position. The current position is also corrected by comparing the obtained current position with map data.

[Problems to be solved by the invention]

However, in such a system that displays the planned driving route and driving trajectory, when the geomagnetic field is detected by the geomagnetic sensor, it is difficult to detect the direction in places where there is a lot of magnetic disturbance such as railroad crossings, railroad tracks, or high-voltage lines, or because the vehicle body is magnetized. Errors may occur and the accuracy of detecting the current location is not very good. Also, the gyro is expensive, and the method of correcting the current location by comparing the value obtained by calculation with map data is limited by the amount of data. There are many problems, and the disadvantage is that it takes a long time to process the calculations.

The present invention is intended to solve the above-mentioned problems, and it is possible to accurately correct the distance for each intersection without receiving disturbances, and also to calculate the current position with less data and speed up the processing speed. An object of the present invention is to provide a vehicle navigation device having a current position calculation means.

[Means for solving problems]

For this purpose, the vehicle navigation device having the current position calculating means of the present invention inputs a distance sensor, a steering angle sensor, a distance signal, and a steering angle signal, and calculates the vehicle's traveling direction by referring to a steering angle-direction conversion table. A curve detection section that calculates the change; a route search section that receives the current location and destination and searches for a route from intersection data, road data, and node data; a comparison/judgment unit that compares and determines whether the difference is within a predetermined value; and a guidance processing unit that calculates the current position by correcting the distance based on the intersection position data or node position data when the difference is within the predetermined value. It is characterized by having the following.

[Action and effect of the invention]

The present invention compares the angle at which the vehicle should turn at a guide intersection or node on the course with the detected angle, and determines whether the vehicle has turned at the intersection or node at which it should turn on the course, based on whether the difference is within a predetermined value. Did you pass by?
It determines whether or not the vehicle has turned in a different direction, and if the vehicle has turned correctly, it calculates the current position by correcting the distance based on the intersection position data or node data, and uses a small amount of course data with high precision without being affected by external disturbances using an inexpensive configuration. It is possible to calculate the current position using the following commands, thereby increasing the processing speed.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a vehicle navigation device having a current position calculation means according to the present invention, where l is a distance sensor, 3 is a steering angle sensor, 5 is a current location/destination input unit, 7 is a navigation processing unit, 9 is a curve detection section, 11 is a comparison/
13 is a route search unit, 15 is a guidance processing unit, 17 is a steering angle-direction conversion table, 19 is an intersection data file, 21 is a node data file, 23 is a road data file, 25 is a search route data file, 27 is a photo data file, 29 is a map data file, 31 is a display section, and 33 is an audio output section.

The distance sensor l measures the traveling distance of the vehicle, and may be one that detects and counts the number of rotations of the wheels, or one that detects acceleration and integrates it twice, but other measurement means may also be used. The steering angle sensor 3 detects whether or not the intersection has been turned. For example, an optical rotation sensor or rotation resistance volume attached to the rotating part of the steering wheel can be used, but the steering angle sensor 3 can be The current location/destination input unit 5, which may be a sensor, may be a joystick, keys, touch panel, or may be combined with the screen of the display unit 8 to display keys and menus on the screen and input from that screen.

The navigation processing section 7 is the core of the navigation device, and includes a curve detection section 9, a comparison/judgment section 11, a route search section 13, and a guidance processing section 15.

When the current location and destination are input from the input unit 5, the route search unit 13 reads intersection data, node data, and road data as described later from each file, searches for a route, and sends the search route to a file 25. Store. The curve detection unit 9 reads the detection outputs from the distance sensor 1 and the steering angle sensor 3, as described later, and converts the steering angle to traveling direction conversion table 1.
7 to detect a change in the direction of the vehicle. The comparison/judgment unit 11 compares the intersection angle or node angle of the searched route near the guide intersection on the course and between the guide intersections with the angle detected by the curve detector 9, and determines if the difference between the two is within a predetermined value. If so, it is determined that the intersection or node has been turned correctly. When the comparison/determination unit 11 determines that the vehicle has turned correctly, the guidance processing unit 15 calculates the current position by correcting the distance using intersection data or node data. In this case, the current position is calculated as the distance from the intersection at which the vehicle turned last time. Further, the guidance processing unit 15 displays the calculated current position as necessary, or plays it as audio, sequentially displays characteristic photographs at guidance intersections of the search route or in the middle of the course, or displays a guidance map. In addition to displaying the remaining distance to the next intersection and other guidance information, the audio output unit 25 outputs an audible direction, and when a deviation from the course is detected, a message to that effect is displayed, and the course is audibly displayed. Notify the driver that it has come loose.

Next, the processing of the curve detection section will be explained with reference to FIGS. 2 and 3.

When the curve detection unit 9 receives detection signals from the distance sensor 1 and the steering angle sensor 3, it calculates a change in the traveling direction of the vehicle with reference to the steering angle-travel direction conversion table 17. As shown in FIG. 2, the steering angle/direction conversion table 17 converts the steering angle θ into a change in the traveling direction Δα per unit distance II. Then, as shown in FIG. 3, the curve detection unit 9 adds (integrates) Δα to the detected steering angle from when the steering angle exceeds the threshold value a until it returns to within the threshold line. From this added value, it is calculated how much the direction of travel of the vehicle has changed from when the steering wheel starts to be turned until it is completely turned back. 3 represents the intersection detection range, l represents the inspection range after angle detection, a certain distance from when the steering wheel is turned back in consideration of lane changes, etc., and d represents the distance from the bending point to the determination.

The comparison/judgment unit 11 compares this calculated change in the direction of travel with the intersection angle of the road at the intersection at which the turn should be made, that is, the direction in which the road should be taken, read out from each file, and determines whether there is a difference of more than a predetermined value between them. Find out. If this difference is within a predetermined value, it is determined that the vehicle has turned at the intersection or node where it should have turned, and if it is greater than a predetermined value, it is determined that the vehicle has turned at the wrong intersection. do.

Next, the intersection data, node data, and road data used for route searching will be explained.

Intersection data is information about roads that intersect at intersections, node blocks are information about crosswalks and tunnels that are feature points on the course that can be detected by sensors, etc., and road data is information about the road, such as starting points and ending points.

FIG. 4 is a diagram showing an example of a road network, intersection data, road data, and node string data.

In order to accurately determine the distance from a vehicle's current location to its destination at any time, a road network such as that shown in Figure 4 (
If the intersection numbers 1 to ■ are made up of road numbers ■ to ■ as shown in a), the intersection data will be as shown in the figure (
bl, road data as shown in tel in the same figure, and node data as shown in fd+ in the same figure.

In other words, the intersection data includes the intersection name, the lowest road number among the roads where the intersection is the starting point, and the intersection where the intersection is the ending point, as shown in the same figure (bl). It consists of the lowest road number among the roads in the road, and the presence or absence of traffic lights.

In addition, as shown in fcl in the same figure, the road data corresponds to the road numbers Φ to ■, and includes starting points and ending points by intersection numbers, roads with the same starting point with the next number, and roads with the same ending point with the number It consists of the following: road size, prohibition information, information not requiring guidance, photo number, number of nodes, start address of node string data, length, etc.

The node data consists of east longitude, north latitude, attributes, etc., as shown in FIG. 4(d), and as is clear from the road data, the unit of road number consists of a plurality of nodes. In other words, node data is data about one point on a road, and if the connection between nodes is called an arc, a road is expressed by connecting each of a plurality of node strings with an arc.For example, a road Regarding number ■,
According to the road data, the number of nodes is 15 and the start address of the node data is 100, so the road number ■ is 1.
It is composed of node data of addresses from 00 to 114.

According to these network data, for example, if we focus on intersection number I, for a course starting from this point, we will first search for the road number ■ based on the starting point information of the intersection data, and then search for the road number ``same starting point'' in the road data related to this road number ■. The road number ■ is searched from "roads with the following numbers".

Contrary to the similar information regarding the road number ■, since it is the road number ■, it can be determined that there are no surrounding roads with other road numbers. This also applies to the end point. In addition, the road number ■ in the road data is
Since the road number ■ is prohibited, Figure 4 (al
At the intersection number ■ of the network shown in , it is impossible to enter from road number ■ to ■ because right/left turns are prohibited, and the only road that can be entered is road number ■. Therefore, there is no need for guidance when entering this road number ■.

Figure 5 shows the data generated by the route search, (al
is intersection string data, and (b) is node string data.

The intersection string data consists of information such as the intersection name, intersection number, photo number of the characteristic landscape of the intersection, turning angle, distance, etc. Also, the node string data includes the node position as shown in the same figure (bl). It consists of information such as east longitude, north latitude, intersection number, attribute, angle, distance, etc. Furthermore, these data consist only of intersections that require guidance, excluding intersections that do not require guidance.Therefore, in navigation , this data may be sequentially read and output corresponding to a predetermined position.

The present invention accurately grasps the travel of a vehicle while accurately recognizing the current position at any time based on intersection data, road data, node sequence data, etc.

Next, navigation according to the present invention will be explained with reference to the flowchart shown in FIG.

First, input the exit of the parking lot where the vehicle is normally parked as the starting point (step 101).
Read the distance sensor and rudder angle sensor detection values (Step 1)
02.103), the amount of change in the detected value of the distance sensor is calculated (step 104).

When it is detected that the amount of change in the detected value of the distance sensor is not 0 and that the vehicle is traveling, a curve detection routine to be described later is performed (step 106). If a curve is not detected between intersections, the distance sensor calculates the current position assuming that the vehicle is proceeding on the course without turning, and if a curve is detected, a similar position is calculated near the current position on the course. Check whether there is a curve or not by comparing the angles based on the node string data and calculating the difference. If there is a similar curve, it is determined that the vehicle is traveling on that course, and if there is not, it is determined that the vehicle is traveling on that course. Decide that you have deviated from the course.

When a curve is detected near a guide intersection where the vehicle should turn, if the difference between the angle in the direction of travel and the detected angle is smaller than a certain value, it is determined that the vehicle has turned in the correct direction on the course, and if it is larger, it is determined that the vehicle has deviated from the course. . Additionally, if a curve is not detected after traveling a certain distance near an intersection, it is determined that the vehicle has passed the intersection and has deviated from the course. After going through such a course deviation routine (steps 107 and 108), the current position is calculated by subtracting the traveled distance from the remaining distance to the next intersection (step 109). These processes are repeated until the destination parking lot population is reached (step 110).
).

Next, the curve detection routine will be explained based on FIG.

First, a curve detection routine is entered in a start step 201, and it is determined whether the steering angle is larger than a predetermined value a (step 202). If it is, the change in the traveling direction Δα according to the current steering angle θ is In addition to the direction of the vehicle, step 204) determines whether the current location is within the detection range from the intersection at which the turn should be made from the mileage data.Step 205), and if it is within the range, turns on the within-range/curve detection flag. 206), if it is not within the range, the in-range/curve detection flag is turned OFF (step 207).Next, it is determined whether the steering angle θ is at the maximum or not (step 208), and when the steering angle is at the maximum, the steering angle is set to OFF. Initialize the distance counter to count the distance from the maximum point of the corner (step 209); if it is not the maximum, add the distance d as it is assumed that the intersection is not turned (step 210); proceed to step 211; this process will result in a turn. If the vehicle turns correctly at the intersection where the vehicle should turn, the distance is corrected using the point where the steering angle is maximum as the intersection, and the distance from this point is then calculated to determine the current position. Further, in step 202, if the steering angle is smaller than the predetermined value a (not turning right or left), it is determined whether the added value of the change in the traveling direction calculated based on the steering angle-travel direction conversion table is larger than the predetermined value a. If there is a change in the traveling direction by a predetermined amount or more (Step 203), the vehicle jumps to Step 210. If the direction does not change more than a predetermined value in step 203, each parameter value is initialized and it is determined whether or not the guide intersection has passed (step 222). If not, return.

Next, in step 211, after the steering angle becomes smaller than a! It is determined whether the vehicle has traveled more than 1 time, and if the vehicle has not traveled more than 1 time, the process jumps to step 224 and returns. In addition, if the vehicle is traveling by 1 or more, it is determined that the steering wheel has been returned and the right or left turn has been completed, and the added value of the change in the direction of travel calculated based on the steering angle - direction of travel conversion table is greater than the predetermined value. , it is determined whether or not there has been a change in the traveling direction more than a predetermined value (step 212). If it is smaller than the predetermined value, initialize each parameter value (step 221) and judge whether or not you have passed within the range of the guidance intersection.Step 2
22), if it is passing, turn off course flag ONL,
, returns if it has not passed the range. Further, in step 212, if there is a change in the direction of travel by more than a predetermined value, it is determined whether the within-range/curve detection flag is ON (step 213), and if it is ON, the road crossing angle is detected as the intersection at which the turn should be made. It is determined whether the difference from the turning angle is less than a certain value C (step 214), and if it is more than a certain value, it is determined that the vehicle has turned in a different direction and has deviated from the course, and the off-course flag is set to 0NL (step 220), within a certain value. If so, it is determined that you have turned correctly at the intersection where you should have turned (step 225), and the distance from the maximum steering angle point @d
is subtracted from the distance to the next intersection as the remaining distance (step 226), each parameter value is initialized (step 221), and since the range of the intersection within the IC has not been passed, the process returns.

In addition, in step 213, when near the guidance intersection (if the within range/curve detection flag is not ON, the remaining distance ±α
(step 217), and checks whether there is a node where the azimuth addition value and angle difference are less than a certain value (step 218). If there is no node that meets the above conditions, it is determined that the curve was caused by a bend at a different intersection and has deviated from the course (step 219).

As described above, according to the present invention, it is determined whether or not the intersection or node on the course has been turned by comparing the curve detected by the steering angle sensor and the distance sensor with the angle of the guidance intersection or node. The current position can be determined by correcting the distance based on the intersection or node position, and calculating the distance from the previous intersection.

Since a steering angle sensor is used as the sensor, the current position can be confirmed with high precision and with an inexpensive configuration without being affected by external disturbances. Furthermore, since node data is used, correction can be made with less course data, and processing speed can be dramatically improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a vehicle navigation device having current position calculating means according to the present invention, FIG. 2 is a diagram showing changes in traveling direction per unit distance with respect to steering angle, and FIG. 3 is a diagram showing calculation of changes in traveling direction. Figure 4 (al.
is the road network, 俤 is the intersection data, (C1 is the road data,
(d+ is a diagram showing node string data, FIG. 5 ta+ is a diagram showing searched guidance intersection data, (b) is a diagram showing searched course node string data, and FIGS. 6 and 7 are navigation processing according to the present invention. This is a diagram for explaining the flow. Applicant Agent: Aisin Warner Co., Ltd.
Patent Attorney Hirukawa Masanobu (3 others) Figure 1 Figure 2 Figure 3 d-Jt! ,,η゛raf'l look at the 10S giant figure 4 (d) figure 5 (a) (b) figure 7

Claims (2)

[Claims] (1) A distance sensor, a steering angle sensor, a curve detection unit that receives a distance signal, a steering angle signal, and calculates a change in the vehicle's direction by referring to a steering angle-direction conversion table, and detects the current location and destination. A route search unit that searches for a route based on input intersection data, road data, and node data compares the angle of the intersection or node of the searched route with the curve detection result, and determines whether the difference is within a predetermined value. A navigation device for a vehicle, comprising a current value calculation means, comprising a comparison/judgment unit that calculates the current position by correcting the distance based on intersection position data or node position data when the difference is within a predetermined value. (2) A vehicle navigation device having a current position calculation means according to claim 1, wherein distance calculation is performed using the intersection position as the point where the steering angle becomes maximum during curve detection.