JPS6015575A - Course guiding apparatus - Google Patents

Abstract

PURPOSE:To perform effective course guidance by obtaining the accurate information of a present position, by correcting the output error of a magnetic azimuth sensor caused by the deflection angle portion of terrestrial magnetism on the basis of the present position of a moving body. CONSTITUTION:The output of a magnetic sensor 1 through an A/D converter 2 is corrected to offset and sensitivity by an initial correcting part 3 and the corrected output is processed with an account device 7 to which outputs of an angle converting part 4, a deflection angle correcting part 3, a unit vector generating part 5 and a distance sensor 6 are supplied while the coordinates of the present position is stored in present position memory 8. In this case, the output error caused by the deflection angle portion of terrestrial magnetism of the sensor 1 is corrected through deflection angle corrected value memory 12 in which a deflection angle corrected value, which is based on the comparison of the content of the memory 8 during running over a predetermined information based on a map from an after-corrected value input part 10, calculated by a deflection angle corrected value operating part 11 is preliminarily written. Therefore, the effective course guidance of a vehicle due to the accurate positional information stored in the memory is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides information on the current position of a vehicle such as a passenger car, etc., which is obtained based on the output of a magnetic direction sensor that detects the geomagnetic direction and a distance sensor that detects the travel distance in a loin guidance device. In a course guidance device for guiding a course of a moving object, an accurate driving course is guided by correcting a declination error of the magnetic azimuth sensor that occurs when the moving object runs based on the current position information. The present invention relates to a course guiding device.

2. Description of the Related Art Conventionally, it has been considered to detect the direction of travel of a mobile object by detecting the direction of earth's magnetism using a magnetic direction sensor that detects the direction of a magnetic field. 1. The current position of the passenger car is extracted based on the outputs of the magnetic direction sensor and distance sensor mounted on a moving body such as a passenger car. 1. For example, the display shows the driving direction at a predetermined point on the driving course In other words, turn left.

In addition to giving direction directions for turning right and going straight, voice guidance provides guidance on approaching the destination, etc.
BACKGROUND ART A course guiding device for a moving object that guides a traveling course is being developed.

The principle of direction detection by the magnetic direction sensor in the above course guidance device will be explained with reference to FIG.

The code 1 in the figure is a magnetic direction sensor, and the orthogonal X,
9 by detecting the geomagnetism in the two axis directions of Y.
For example, as shown in FIG.

The angle θ of the Y direction of the magnetic orientation sensor 1 with respect to the magnetic north direction can be determined. That is, the outputs (Vx, Vy) of the magnetic orientation sensor 1 in the Y-axis and Y-axis directions are expressed by the following equation (1
).

If the Y-axis and Y-axis sensitivity of the magnetic azimuth sensor J are adjusted to be uniform, that is, if Ks = Ky =, then based on equation (1), the magnetic azimuth sensor 1 will be The angle θ of the Y direction with respect to the magnetic north direction is calculated using the following formula (
2).

In this way, the traveling direction of the moving body can be known from the output of the magnetic orientation sensor 1.

However, when the magnetic orientation sensor 1 is mounted in a vehicle made of iron plates, such as a passenger car, it is affected by the magnetization of the iron plates making up the vehicle.
Since the output of the magnetic azimuth sensor is offset, it is not possible to detect the accurate azimuth of the earth's magnetism. Furthermore, the detection sensitivity may vary depending on the mounting position of the magnetic orientation sensor within the handle. Therefore,
For this reason, if the output of the magnetic orientation sensor is simply used as data for determining the traveling direction, there is a problem that an error will occur in the current position display.

In order to solve the above problem, prior to filing the present application, the applicants of this application applied corrections such as offset correction and sensitivity correction to the output of the above-mentioned magnetic azimuth sensor, thereby accurately determining the azimuth in the traveling direction of the moving object. We have proposed a course guidance device as shown in FIG. 2, which is equipped with a magnetic azimuth detection device designed to detect the direction of the vehicle. In the figure, 1 is the magnetic direction sensor, 2 is A
/D converter 9.3 is an initial correction section, 4 is an angle conversion section,
5 is a unit vector generator, 6 is a distance sensor, 7 is an integrator, 8 is a current position memory, and 9 is a display unit.

In FIG. 2, the output Vx of the magnetic orientation sensor 1.

The vyc signal (the Chinese signal shown by equation 1) is converted into a digital signal by the A/D converter 2. The outputs Vz, Vyc of the magnetic orientation sensor 1 are converted into digital signals by the A/D converter 2.
In the initial state, offset correction and sensitivity correction are performed in the initial correction section 3. Note that the initial correction in the initial correction section 3 is performed based on equation (3).

Next, in the angle conversion section 4, the output of the initial correction section 3, that is, the output of the magnetic orientation sensor 1 after correction, V'! , v′
Determine the traveling azimuth θ by y. The traveling azimuth angle θ is determined by the following equation (4).

θ== tan” (V'r /V'y)...
・・・・・・・・・・・・・・・・・・・・・・・・(4)
The unit vector generator 5 converts the output of the angle converter 4, that is, the gin of the running azimuth θ shown by equation (4).
Component and C6, components hθ and cotθ are calculated. Further, the distance sensor 6 outputs a clock pulse every time the vehicle travels a certain distance Δl, corresponding to the rotation of the wheels, for example. In the integrator 7, each time a clock pulse is inputted from the distance sensor 6, that is, each time the moving body travels a distance Δl, the traveling azimuth information section is inputted from the unit vector generating section 5.ぢAbove 51θ and cosr
θ is sequentially integrated, and the integrated values are sequentially stored in the current position memory 8 as current position information of the mobile object.

The current position information stored in the current position memory 8 is as follows.

As shown in FIG. 3, the traveling position P for each distance Δ
1. P2. ..., is the coordinate value of Prh, and is the general (current position information (Xi, Yi
) is expressed by the following equation (5).

Then, based on the contents of the current position memory 8, a display section 9 displays instructions for the traveling direction, etc., corresponding to the current position of the moving body, that is, the position for every distance Δ.
is a display device constituted by, for example, CR', T, or LCD C=.

In the above-mentioned course guidance device (-), the accuracy of the current position display is greatly influenced by the correction of the output of the magnetic direction sensor 1 in the initial correction section 3, especially the suitability of the declination correction. Specifically with reference to FIG. 5 (second explanation, shown in FIG. 4), OP is the output vector of the magnetic orientation sensor 1 in the case of no declination (expressed as a unit vector with a magnitude of 1). However, as shown in FIG. The declination angle α is synthesized (=therefore,
Since the detected azimuth angle θ becomes θ, the current position memory 8 (= stored current position information (= error occurs). Therefore, 9 For example, the current position information when going straight in the direction of the azimuth angle θ is as shown in Figure 2. Traditionally, P.

P, followed by a trajectory l, top (where two should be + “I +
It is stored in the current position memory 8 as being on a trajectory continuing from Pt + PR. That is, as mentioned above, the second
In the illustrated example, since the declination error is not corrected, there is a drawback that an error occurs in the current position information.

The present invention aims to solve the above-mentioned drawbacks,
Accurate current position information is always obtained by correcting the error in the output of the magnetic azimuth sensor due to the declination of the earth's magnetic field based on the current position information of the mobile body obtained from the traveling f= of the mobile body.

It is an object of the present invention to provide a course guidance device that enables effective course guidance. This will be explained below with reference to the drawings.

FIG. 6 is a block diagram showing the basic configuration of an embodiment of the present invention. Symbols 9 to 9 in the figure correspond to those in Figure 2, 10 is a post-correction value input section for inputting position information of a predetermined point read from a map, etc., and 11 is declination correction. 2 is a value calculation unit that calculates a declination correction value by comparing and calculating the position information input from the post-correction value input unit 10 and the contents of the current position memory 8; 2 is a declination correction value memory; 3 is an argument correction unit which stores the argument correction value calculated by the argument correction value calculation unit 11, which stores the argument correction value calculated by the argument correction value calculation unit 11. This represents the correction of the declination angle to the azimuth angle calculated by the angle conversion unit 4 based on the value.

The operations of the magnetic orientation controller 1 to the display section 9 in the embodiment shown in FIG. 6 are the same as the conventional example shown in FIG.

In the present invention, there is provided an argument correction section 13 that performs an argument correction process on the output of the angle conversion section 4 based on the contents of an argument correction value memory 12, which will be described later. Further (
Second, the declination correction section 13 performs declination correction to obtain accurate current position information. Note that the correction process in the declination correction section 13 is performed based on the declination correction value stored in advance in the declination correction value memory 12+=. The declination correction value is calculated by performing the following arithmetic processing in the declination correction value calculating section Ill2.

That is, the true coordinate data of the point when the moving object is driven a predetermined distance (the starting point is the coordinate origin) is read out on the map, and the declination angle correction is performed via the post-correction value input section 10. Value calculation unit 11C=Input. On the other hand, if the magnetic azimuth sensor 1 (= declination error) is included, the current position information stored in the current position memory 8 at that time includes the declination error. This is because the declination correction value has not yet been set in the declination correction value memory 12, so the declination correction section 13 has not performed the declination correction.Therefore, the declination correction value calculation section 11 (=, the contents of the current position memory 8 and the coordinate data input from the post-correction value input section 10 are compared. When the error of this comparison result is measured, the error and the above-mentioned coordinate data are compared. As is known, the angle of deviation α can be determined from the distance from the coordinate origin to the coordinate data input point of the tool,
This can be calculated as the declination correction value to be corrected. The declination correction value is stored in the declination correction value memory 12.
is stored in

In this way, after the declination correction value is stored in the declination correction value memory 12, the declination correction process is performed in the declination correction section 13 based on the declination correction value. After that, the current position information stored in the current position memory 8 becomes accurate.

As explained above, according to the present invention, in order to correct the declination amount of the earth's magnetic field included in the magnetic azimuth sensor (= post-correction value input section), accurate position information at a predetermined point can be obtained. By calculating the declination correction value by comparing and calculating the contents of the current position memory at that point, and by performing declination correction using this declination correction value, accurate current position information is always obtained. This makes it possible to provide effective course guidance.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the magnetic azimuth sensor used in the course guidance device (2), Fig. 2 is a block diagram showing the configuration of a conventional example of the course guidance device, and Fig. 3 shows current position information sent to the course guidance device. An explanatory diagram for explaining one aspect, FIGS. 4 and 5 are explanatory diagrams for explaining the declination error included in the output of the magnetic azimuth sensor. FIG. 6 is an embodiment of the course guidance device of the present invention. It is a block diagram showing an example configuration. In the figure, 1 is a magnetic direction sensor, 2 is an A/D converter, 3
4 is an initial correction section, 4 is an angle conversion section, 5 is a unit vector generation section, 6 is a distance sensor, and 7 is an integrator. 8 is a current position memory, 9 is a display section, 10 is a post-correction value input section, 11 is an argument correction value calculation section, 12 is an argument correction value memory, and 13 is an argument correction section. Patent applicant: Alps Electric Co., Ltd. Representative patent attorney Mori 1) Hiroshi (3 others) Sakae 1 Kuni

Claims (1)

[Claims] It is equipped with a magnetic direction sensor that detects the geomagnetic direction and outputs traveling direction information of the mobile object, and a distance sensor that outputs travel distance information of the mobile object, and is calculated based on the outputs of the magnetic direction sensor and the distance sensor. A course guidance device includes a current position memory in which current position information of the mobile object is stored, and guides a travel course based on the contents of the current position memory. A coordinate data input section for inputting accurate coordinate data of the current position for performing geomagnetic declination correction, and coordinate data of the current position input from the coordinate data input section and the current position memo lJf: a declination correction value calculating section that calculates a declination correction value based on the current position information of the declination correction value calculating section; and a declination correction value calculating section that calculates a declination correction value based on the current position information of the A course guidance device comprising: a declination correction section that performs angle correction.