JPS62140018A - Present position confirmation apparatus for vehicle - Google Patents

Abstract

PURPOSE:To accurately perform correction, by a method wherein a vehicle is allowed to run between two points arbitrarily selected among preliminarily stored points and the drift angle of an earth magnetic sensor is corrected corresponding to each point/ place. CONSTITUTION:An earth magnetic sensor 5 and a running distance measuring device 6 are connected to an operation circuit 2 and the sensor 5 outputs a signal showing the azimuth of the present place to a control circuit 1 and the measuring device 6 measures the running distance from a starting point to output the signal showing said distance. A memory circuit 3 stores the names of other station and public offices etc. and latitudes and longitudes thereof. When the name of the starting point and that of the distination are inputted to the circuit 1, the coordinates thereof are read corresponding to said names from the circuit 3 and operation is performed in the operation circuit 2. When a vehicle reached the distination, operation in the operation circuit 2 from the outputs of the sensor 5 and the measuring device 6 and the coordinates of the starting point and operation is further performed to calculate a distance correction constant and a drift angle correction constant which are, in turn, stored in a memory circuit 3. At the time of a usual state, the present position is recognized from the output signals from the sensor 5 and the measuring device 6 and correction coefficients to be displayed on a display device 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a current location recognition device for a vehicle, and more particularly to an ``i'' dual-purpose current location recognition device equipped with at least a geomagnetic sensor.

(Prior art) The current location recognition device for a vehicle as described above is disclosed in, for example, Japanese Patent Application Laid-open No. 57-206812 and Japanese Patent Application Laid-open No. 57-206812.
It is commonly used in vehicle travel guidance devices such as those described in Japanese Patent Publications. However, since this current location recognition device is equipped with a geomagnetic sensor as described above, declination correction is required. As a method for correcting the declination angle, there is a known correction method in which the fluxgate geomagnetic sensor is mounted on the vehicle at an angle corresponding to the declination angle, as described in Japanese Patent Application Laid-Open No. 57-128812. In this correction method, once the geomagnetic sensor is installed, its orientation cannot be changed, which causes a large error when the vehicle moves to a location with a different declination angle.

(Objective of the Invention) Therefore, an object of the present invention is to provide a current location recognition device for a vehicle that can accurately correct a geomagnetic sensor.
It shall be white.

(Structure of the Invention) The present invention provides a current location recognition device for a vehicle equipped with at least a geomagnetic sensor m, including a storage means a for storing coordinates of at least two predetermined points, and a vehicle traveling between the two points where the coordinates are stored. Detection means b for detecting that the vehicle has traveled on the map based on the stored coordinates, azimuth calculation means C1 for calculating the direction on the map between the two points where the vehicle has traveled, and the direction between the two points detected by the geomagnetic sensor. Direction correction means d for correcting the direction based on the calculation result of the direction calculation means
It is characterized by having the following.

(Operations and Effects of the Invention) In other words, the present invention corrects the declination angle of the geomagnetic sensor according to each point/location by driving between two points arbitrarily selected from pre-memorized points. Therefore, the declination angle can be corrected accurately, and the declination angle can be corrected without error at each point.

(Embodiment) A vehicle current location recognition device according to a preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

First, the principle of the present invention will be explained with reference to FIG.

If the coordinates of departure point A are (X (1, yo)) and the coordinates of destination B are (x+, yI), and the vehicle travels from departure point A to a destination on a different day, if there is an error in the current location recognition device, The destination B is recognized as B'.If the coordinates of this recognized destination B' are (X2, y2), then the point A-
Straight line distance between B. , the straight line distance between points A and B', and the azimuth angle θ of destination B. , the azimuth angle θ of the recognized destination B' are expressed by the following equations.

Lo = (x+ xo)'+ (31'+
5'0)2---(1)L = (x2-xo)
2+ (y2-yo)'' --(2)yI -yO If we calculate the distance correction constant R from the above equation, we will get, and if we calculate the declination correction constant △θ, we will get △θ=θ-θ.
(6) becomes. Therefore, this R'J6 and △
If the correction is made using θ, the correct current location can always be recognized.

FIG. 3 is a circuit diagram showing a current location recognition device according to an embodiment of the present invention.

In FIG. 3, reference numeral 1 indicates a control circuit constituted by a microcomputer, and this control circuit 1 includes an arithmetic circuit 2 and a storage circuit 3 connected thereto. A geomagnetic sensor 5 , a mileage measuring device 6 , and an operation switch 7 are connected to the arithmetic circuit 2 via an input/output ink face 4 . The geomagnetic sensor 5 is a fluxgate geomagnetic sensor that outputs a signal representing the direction of the current location to the control circuit 1. The mileage measuring device 6 measures the distance traveled from the starting point to the current location based on the number of rotations of the tires, etc., and outputs a signal indicating the distance traveled to the control circuit 1. In addition, the memory circuit 3 has the above formulas (1) to
In addition to (4), the names of stations, government offices, famous places and historic sites, etc. and their east longitudes,
Position coordinates such as northern latitude are stored in advance. This storage circuit may be an external storage circuit.

The operation switch 7 can be operated by the dryer to
By inputting the departure place name, destination name, etc. manually into the control circuit 1,
A signal indicating that the vehicle has traveled from its current location and arrived at its destination is manually input to the control circuit 1.

When the name of a departure place and the name of a destination are entered manually, the control circuit 1 reads out the coordinates from the memory circuit 3 according to the name of the place, and the arithmetic circuit 2 calculates equations (1) and (3). Further, when the destination is reached, the calculation circuit 2 calculates equations (2) and (4) from the outputs of the geomagnetic sensor 5 and the road distance measuring device 6 and the coordinates of the starting point. The calculation circuit 2 further calculates equations (5) and (6) from the answers to equations (1) to (4) above, and calculates the distance correction constant R1 and the argument correction constant △.
Find θ. These constants R and Δθ are stored in the storage circuit 3. The above operations are shown in a flowchart as shown in FIG.

In the normal state, the control circuit 1 controls the ground 61j.
z The current location is recognized using the output signals from the 6m air sensor 5 and the mileage measuring device 6 and the correction constants R and △θ, and the signal indicating the current location is sent to the human output interface 4.
The current location is outputted to a display device 8, such as a CRT, through which the current location is displayed.

To display this current location, it is preferable to store a map in advance in an external storage device, display this on the display 8, and display the current location on this map. This current location display is used to guide the vehicle.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the vehicle current location recognition device of the present invention, FIG. 2 is an explanatory diagram illustrating the principle of declination correction, etc. of the vehicle current location recognition device of the present invention, and FIG. 3 is the present invention. FIG. 4 is a circuit diagram of a vehicle local recognition device according to an embodiment of the invention. FIG. 4 is a flowchart for explaining the operation of the control circuit. a...Storage means, b...Detection means, C
... Direction calculation means, d ... Direction correction means, m ... Geomagnetic sensor Fig. 3

Claims (1)

[Claims] In a current location recognition device for a vehicle that includes at least a geomagnetic sensor, a storage means for storing the coordinates of at least two predetermined points, a detection means for detecting that the vehicle has traveled between the two points whose coordinates are stored, and a detection means for detecting that the vehicle has traveled between the two points whose coordinates are stored; azimuth calculation means for calculating a direction on a map between two points where the vehicle has traveled based on the coordinates of the vehicle, and correcting the azimuth between the two points detected by the geomagnetic sensor based on the calculation result of the direction calculation means. A current location recognition device for a vehicle equipped with an azimuth correction means.