JPS63211500A - Navigator for vehicle using steering angle sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vehicle that uses a steering angle sensor that can obtain an accurate current position of a route on a map in a navigation device that follows a predetermined route. The present invention relates to a navigation device.

[Conventional technology]

Conventional vehicle navigation devices include a distance sensor that detects the distance traveled by the vehicle, a direction sensor that detects the direction in which the vehicle is traveling, and a map storage device, and the current position of the vehicle is recorded on a map surface image read from the map storage device. It has been proposed to simply display the information.

FIG. 8 is a diagram showing the configuration of a conventional vehicle navigation device, where 1 is a map storage device, 2 is a distance sensor, 3 is a direction sensor, 4 is a switch and touch panel, 5 is an input interface, 6 is an internal bus, 7 is CPU, 8 is RAM,
9 is ROM, 10 is output interface, 11 is CR
It is T.

In the figure, a map storage device 1 in which map data is stored is comprised of a video disk, videotape, CDROM, etc., from which map data for a specific area is read out and displayed on the CRT II as needed. Distance sensor 2
Usually detects the number of rotations of tires and generates distance data for each unit distance. The azimuth sensor 3 normally detects the direction of the earth's magnetic field according to the traveling direction of the vehicle and generates azimuth data.

The distance sensor 2 and direction sensor 3 are combined to detect the travel distance and direction from the starting point, or right/left turns, calculate the current position of the vehicle on a predetermined route, and display it overlaid on the map. . The switch and touch panel 4 are operated by the driver to input data such as inputting a destination and enlarging a map.
Enter AM8. For example, the touch panel is CRT 11
The touch screen is mounted on the display surface of the display screen, and by operating a specific touch area among the divided touch areas, a corresponding signal is generated. The input interface 5 is a signal conversion device for sending inputs from each sensor, storage device, switch, etc. to the internal bus 6. Programs for input/output of various data and data processing via the input interface 5, output interface 10, and internal bus 6 are input to the ROM 9, and are executed by the CPU 7.

[Problems to be solved by the invention]

However, the mileage sensor in conventional navigation devices detects the number of rotations of the tires and converts this detected value and tire radius into mileage, but the tire radius changes depending on tire pressure, wear status, etc. Also, if you change lanes while driving and drive diagonally, an error will occur in the detected distance, so even though the true current position is T, as shown in Figure 9, Current position M
The problem was that it could be detected incorrectly.

Additionally, since the direction sensor detects the direction of the earth's magnetic field, as shown in Figure 10, at railroad crossings and railroad tracks where there are many magnetic disturbances, the true current position T may be mistakenly detected as the current position M. arise. This azimuth detection error also occurs in places such as high-voltage lines, or even when the vehicle body is magnetized.

The present invention is intended to solve the above-mentioned problems.By correcting the distance detection error every time a left or right turn is detected on a predetermined route to the target value, the present invention eliminates the occurrence of a distance detection error and eliminates disturbances. It is an object of the present invention to provide a navigation device that prevents errors in direction detection caused by.

[Means for solving problems]

For this purpose, the vehicle navigation device using the steering angle sensor of the present invention includes a distance sensor that detects the distance traveled by the vehicle and generates a distance signal, a steering angle sensor that detects the steering angle, and a steering wheel that detects the distance traveled by the vehicle. A storage means for storing the history of corners, a calculation means for calculating the current position based on the detection signals from the distance sensor and the steering angle sensor, and a calculation processing means for determining whether to turn left or right at an intersection, etc., and displaying the calculated current position on the map display screen. When it is detected that the vehicle is approaching a specific intersection within a predetermined distance based on the travel distance calculated from the distance sensor, the display means displays a display unit that displays the information based on changes in the steering angle and the stored steering angle history. The present invention is characterized in that it detects whether or not a right or left turn has been made at an intersection, and that the distance detection error is corrected each time a right or left turn is detected.

[Action and effect of the invention]

A vehicle navigation device using a steering angle sensor according to the present invention uses a steering angle sensor as an azimuth sensor, and is provided with a storage means for storing a history of steering angles corresponding to travel distance, and the vehicle navigation device uses a steering angle sensor as an azimuth sensor. When it is detected that the vehicle has approached a specific intersection on the route within a predetermined distance based on the distance,
Turns are detected by checking changes in the steering angle and the history of the steering angle according to travel distance, and each time a left or right turn is detected, the error in detecting the distance between intersections is corrected. It is possible to correct distance detection errors caused by diagonal driving due to changes in lanes, changes in wear conditions, etc., and heading detection errors caused by disturbances.Since the error in section distance is calculated for each section, the error does not accumulate. It is possible to prevent this from happening.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a vehicle navigation device using a steering angle sensor according to the present invention. The same numbers as in FIG. 8 indicate the same contents, and detailed explanation thereof will be omitted. In addition, 12 in the figure is a steering angle sensor.

In the figure, the steering angle sensor 12 assumes that the steering angle when traveling straight is O, and based on that, the left direction is (+) and the right direction is (-).
) to detect the rudder angle. Changes in the steering angle detected in this manner are checked according to the travel distance.

Figure 2 (a) is a diagram showing changes in steering angle when turning left;
FIG. 2(B) is a diagram showing changes in steering angle when changing lanes.

As shown in Figure 2 (a), when the steering angle returns to a or less after a change in steering angle of 82 or more to the left is detected, it is detected that the steering wheel has been turned to the left, and then Distance MIl
If a similar change in steering angle in the opposite direction is not detected between 0 and 0, it is determined that the vehicle has turned in that direction. That is, Fig. 2 (
As shown in Figure 2 (B), if a change in steering angle in the opposite direction is detected within a distance of N1 after a change in steering angle as shown in Figure 2 (A) is detected, a lane change is determined and a right or left turn is detected. Furthermore, the reason why the steering angle change is detected at two levels and has hysteresis is because the actual steering angle change does not draw a smooth waveform as shown in the figure, but pulsates, so it is not possible to judge it from an instantaneous change. This is to avoid misjudging that a right or left turn has been made over the peak.

The above judgment starts when the intersection position (temporary position) considered based on the distance traveled is approached within a certain distance of 1JILLL, and when a right or left turn is detected, the data obtained from the distance sensor indicates that the intersection position has not yet been reached. (However, this is determined to be a distance detection error, and the distance error is corrected by determining that the intersection was turned left or right, and is treated as data for subsequent current position detection.)

Next, detection of right or left turns will be described in detail with reference to the navigation processing flow shown in FIG. 6 and the waveform chart of changes in steering angle with respect to distance shown in FIG. 7.

First, the variable names and their contents in the flow are as follows.

Wk: Counter contents for tracing back from the current moment to the past i ST[0] to ST[255]: Array 5TNOj that stores the history of steering angle sensor values relative to distance ST[01 to ST[255] The latest steering angle Array number containing sensor value RESTD: 1st intersection p from (+-1)th
After k : az ≦ (latest rudder angle) (!
l New rudder angle) ≦ a (Part A in Figure 7 (A)) -1 (Latest rudder angle) ≦ -32 until -a1 ≦ (Latest rudder angle) Until ・−・−・・・−・
・-1-a, < (latest steering angle) when a, ・--・-m-
...0ppk: al ≦ (latest rudder angle)
Or, when (latest rudder angle) ≦ -a o... After 0 - al < (latest rudder angle) < When it returns to al (Fig. 7 (a) point p), pk. Memorize the value (right turn knee 1, left turn: 1) pkl: When ppk≠0, the same value as pk when performing the same process as pk from the present to the past ppkl: Perform the same process as ppk on pkl A value similar to ppk at the time of going dir: Defined as ppk + ppkl, and a value indicating which direction you turned in total within the past distance β from the current time (right turn: negative number, left turn: positive number) fek: calculation of dir - ppk + ppkl After, d
1 if ir≠0, O if dir- O 1: Intersection data number j: Contents of the counter to perform pkl, ppkl processing twice in succession Start Navigation processing starts from step 100, and the purpose is first set. Values are set (step 101). In step 102, route data is read, and i representing the intersection number is set to 1 (step 103). Step 1
In step 04, it is determined whether the intersection number is smaller than the number of intersections to turn on the route, and if YES, step 10
Proceed to 6. If NO, it means that you have passed all the intersections you should turn on the route, so the navigation process is E.
The result is ND (step 105).

Next, the section distance from the (i-1)th intersection to the first intersection is set in RESTD, and the distance sensor value is read (steps 106 and 107).

In step 108, it is determined whether the previous distance sensor value and the latest distance sensor value are equal, and if YES, the distance has not progressed, so the process returns to step 107 again.
If so, read the steering angle sensor value as an array of ST[TRIP] (step 109), and in step 110 read the steering angle sensor value as an array of ST[TRIP].
Set the IP value to 5TNO and TRIPS, and
Update RESTD to the value of RESTD-1. In step 111, it is determined whether the content of RESTD (distance to the next intersection to turn) is less than or equal to a constant. If YES, proceed to the next step; if NO, return to step 107. In steps 107 to 111, it is detected whether the vehicle has approached the intersection to be turned within a predetermined distance, and the history of the steering angle relative to the distance is stored.

Next, in steps 112 and 114, it is determined whether the latest steering angle is 38 or more or less than -ag, and if YES, ppk is set to 0 and pk is set to 1 or -1 (steps 113 and 115). , if NO in either case, proceed to step 116, determine whether the latest steering angle is between -a and a, and if YES, set the value of pk to ppk; if NO, proceed to step 116. The process proceeds to step 118. In step 118, it is determined whether the value of ppk is O, and for example, a
If there is a change in the steering angle greater than or equal to t, or less than or equal to -a, and ppk is O in step 113 or step 115, the answer is YES and the process jumps to step 144.
The distance sensor value is read again, the steering angle is updated (steps 145 and 146), and the process returns to step 112. At this time, if the rudder angle has returned to or below al, in step 117 pp
Since the value of k2pk is set to 1 or -1, the answer in step 118 is NO, and the process proceeds to step 119. In this way, in steps 112 to 118, it is detected whether the steering angle has changed by a predetermined amount or more and whether the steering angle has returned to its original state.

Steps 119-131 are past, distance! 31 within II1
A steering angle greater than or equal to -a or less is detected, and it is checked again whether it is less than or equal to a or greater than or equal to -a.

First, the array number containing the latest steering angle sensor value is set as the counter value Wk, 0 is set as pkl, and j is set to O (steps 119 and 120). Initially, j is 0.
Therefore, step 121 becomes YES, and step 1
Set ppkl to O at 22. Since ppkl is O and Wk#5TNo-1, step 123 is YE.
S, and in steps 125 to 130, the previous step 1
In a process similar to 124118, it is detected whether the steering angle has changed by a predetermined amount or more in the past and whether the steering angle has returned to its original value. Since the answer in step 118 is NO, as shown in Fig. 7 (
As shown in b), such a change is detected at least once. That is, first in step 126 or 128 ppk
l is set to 0, pkl is set to 1 or -1, and Wk is set to W
k-1 (step 131), similar processing is performed, and when the steering angle returns, ppkl is set to 1 or -l and pkl is set to 0 in step 130. Since ppkl is O, step 123 becomes No, and j is set to 1 in step 124. Since j is 1, the step 121 becomes YES, ppkl is set to 0 in step 122, YES is returned in step 123, and again in steps 112 to 118, it is determined that there has been a change in the steering angle in the past by more than a predetermined value, and the steering angle has changed to the original value. It is detected whether or not it has returned to .

For example, in the case shown in FIG. 7 (b), ppkl remains 0 and Wk-3TNO-j! The process is repeated until j is set to 2, and in the case shown in Figure 7 (c) (corresponding to the case where the vehicle is pulled in the direction of the turn in advance when turning at an intersection), Following the same process, ppk
l is set to 1 and j is set to 2, and in a case like FIG. 7(d), ppk is set to -1 and j is set to 2.
is set and jumps to step 132. In step 132, the value of pp)c+ppkt is set to dir, and in step 133, ppl pkSppkl, pkl
are returned to 0 (in step 134, dir
Determine whether or not is 0. This dir is +1 in the cases shown in Figure 7 (B) and Figure 7 (C), becomes -1 when the steering angle changes in the opposite direction, and becomes -1 when changing lanes as shown in Figure 7 (D). In this case, it becomes O. Therefore, if dir=0 and there is no right or left turn, fpk is set to 0, and dir is set to the value of ppk (steps 135 and 136), and if dl"≠0, fwk is set to 1. Steps 138 to 14
3 is a step for determining whether to turn right or left, first step 13
8, it is determined whether f and k are 1. And fob-1
Step 14
0.141) If YES, it is determined that it is a right or left turn and the intersection number is set to i+l. If NO in either case, the process advances to step 144 and begins the operation of reading the distance sensor value again.

The above process will be continued until all intersections have been passed.

In the above embodiments, right and left turns at intersections were made using only the steering angle sensor signal, but the navigation device also has a CD.
A landscape image storage device such as ROM is provided to memorize intersections to turn on the route, etc.
Data representing the characteristics of an intersection as shown in Figure 5 is stored, and for example, when approaching an intersection where a turn is to be made, a landscape image of the intersection and the characteristics of the intersection are displayed. You may make it use together.

FIG. 3 is a diagram showing the contents of route data 0 stored in advance, FIG. 4 is a diagram showing intersecting road directions, and FIG. 5 is a diagram for explaining a landscape feature point indicating method.

In the figure, D represents the number of intersections to turn on the route to the target value, and Dt represents the intersection scenery image number, indicating the location where the corresponding intersection image is stored in the intersection scenery image storage device (not shown). The a Ds shown is the intersection name, and D4 is the section distance from the (i-1)th intersection to the i-th intersection. Ds is the number of intersecting roads; for example, in the case of a three-way intersection, it is three. D is the data on the direction of the intersecting road, which is expressed as a number from 0 to 15 as shown in Figure 4, and the corresponding intersecting road direction is listed by selecting the number closest to the direction of each intersecting road. do.

D is the traveling direction data, which is selected from the numbers 0 to 15 in FIG. D represents the number of feature points at the intersection,
D indicates the coordinates for displaying the feature points as an image,
As shown in FIG. 5, it represents the XSY coordinate values on the screen of two diagonal vertices of a rectangle surrounding a feature point in an intersection landscape image.

The first intersection data is represented by such data D2 to D.

In this way, if the landscape image and its characteristic parts are displayed in accordance with the detection of right or left turns at intersections by the steering angle sensor, it will be possible to determine which intersection to turn at, such as when multiple intersections are adjacent to each other, using only a map. Even in difficult situations, it is possible to easily determine which intersection to turn at, and at the same time know the name of the intersection, the distance to it, the shape of the intersection, and the direction of travel, allowing even more accurate turn detection using the steering angle sensor. This allows the driver to reach the destination with peace of mind and improves driving safety.

As described above, according to the present invention, on a determined route,
Since the distance detection error can be corrected each time the vehicle turns left or right, it is possible to accurately detect the current position, and since the steering angle sensor is used to detect the direction, there is no possibility that errors in direction detection may occur due to disturbances. In addition to detecting left and right turns using the steering angle sensor, by displaying landscape images and characteristics of intersections on the route, it becomes possible to detect left and right turns with even higher accuracy using the steering angle sensor. The driver can reach the destination with peace of mind, and driving safety can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of a vehicle navigation system using a steering angle sensor according to the present invention, and FIG.
Figure (a) is a diagram showing the change in steering angle when turning left.
Figure (b) shows the change in steering angle when changing lanes.
FIG. 3 is a diagram illustrating a navigation processing flow by a vehicle navigation device using a steering angle sensor according to the present invention. Fig. 4 is a waveform diagram of changes in steering angle, Fig. 5 is a diagram showing the contents of route data stored in advance, Fig. 6 is a diagram showing the direction of intersecting roads, and Fig. 7 is a diagram explaining a method of specifying scenic feature points. Figure 8 is a diagram showing the configuration of a conventional vehicle navigation device, Figure 9 is a diagram showing the true position on the route and the current position due to distance detection error, and Figure 10 is a diagram showing the true position on the route. FIG. 3 is a diagram showing a current position based on position and orientation detection errors. 1... Map storage device, 2... Rudder angle sensor, 3...
Distance sensor, 4...Switch/touch panel, 5...
・Input interface, 6...internal bus, 7...
CPU. 8...RAM, 9...ROM, 10...output interface, 11...CRT. 1℃ Buried Masu Buried"j: 100 river plows (outer 2nd floor 2nd floor E layer section Figure 3 Figure 6 (A) Figure 61 (C) Figure 7 Figure 8 Figure 9 Figure 1o

Claims (2)

[Claims] (1) A distance sensor that detects the traveling distance of the vehicle and generates a distance signal, a steering angle sensor that detects the steering angle, a storage means that stores the history of the steering angle according to the traveling distance, the distance sensor and the steering wheel. arithmetic processing means that calculates the current position based on the detection signal from the corner sensor and determines whether to turn left or right at an intersection;
A display means for displaying the calculated current position on the display screen of the map, and when it is detected that the vehicle is approaching a specific intersection within a predetermined distance based on the travel distance determined from the distance sensor, the steering angle changes and is stored. The present invention uses a steering angle sensor that detects whether or not a left or right turn has been made at the intersection from the history of the steering angle that has been detected, and corrects the error in detecting the distance between each intersection each time a left or right turn is detected. Vehicle navigation device. (2) Detection of a right or left turn at the intersection is performed by detecting that the steering angle becomes equal to or greater than a first angle, and then becomes equal to or less than a second angle smaller than the first angle, and at the same time, it is detected that the steering angle becomes equal to or greater than a first angle. A vehicle navigation system using a steering angle sensor according to claim 1, which performs the detection based on whether or not there is a similar steering angle change in the opposite direction.