JPS63317716A - Navigation apparatus for vehicle - Google Patents

Abstract

PURPOSE:To improve the precision of a navigation apparatus by conducting a corrective processing on the basis of a running distance for a tunnel part which is detected by a sunshine sensor and a running distance sensor, and the distance of the tunnel stored in an external storage device. CONSTITUTION:When a sunshine sensor 4 detects a change from a light state to a dark state, a distance counter is reset to integrate an output pulse from a running distance sensor 3 which is given when a vehicle runs inside tunnel. The integrating sensor 4 determines periodically whether or not the dark state changes to the light. When the sunshine sensor 4 determines that the dark state changes to the light, the content of integration of the distance counter is stored and registered in a prescribed address of a random access memory 8. The full distance of the tunnel is read out of an external storage device, and a correction coefficient is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a navigation device for a vehicle, and particularly to a navigation device for a vehicle that can automatically obtain a required correction value for the distance traveled by the vehicle. The present invention relates to a navigation device.

[Prior Art] As a conventional vehicle navigation device of this type, for example, one disclosed in Japanese Unexamined Patent Publication No. 61-21.5918 is known. FIG. 4 is a block diagram showing the above-mentioned conventional device. In FIG. 4, (41) is a position calculation means for calculating the current position of the vehicle, and calculates the current position of the vehicle based on the outputs of the magnetic azimuth sensor (42) and the movement amount sensor (43). Here, the movement amount sensor (43) outputs, for example, a distance detection signal (for example, a pulse signal) according to the rotation of the wheels of the vehicle.

This distance detection signal is subjected to distance correction by the distance correction means (41a) and then inputted to the position calculation means (41). Also,
The correction coefficient calculation means (41b) performs distance correction (
In the distance m correction mode (hereinafter referred to as distance m correction mode), a correction coefficient is automatically calculated as a ratio of the apparent moving distance to the true moving distance. The map data storage means (44) is for storing road network data based on the road map in a predetermined area. Input child 1','! (45) consists of a keyboard, etc., which is used to input necessary data when displaying a guide, and to input necessary operation commands when performing the distance control Uramasa. In addition, map data calculation means (46
) performs the necessary control processing based on the human input signal from the input means (45), the position calculation means (41), the ground data storage means ``2 (44), kfu side (1,000 E'1 (47) and the results are displayed on a suitable display means (48), such as a CRT.
As mentioned above, the traveling distance sensor used to calculate the current position of the vehicle is a wheel rotation speed sensor that generates a number of pulses corresponding to the rotation speed of the vehicle's wheels (=W). By integrating the number of pulses, the distance traveled by the vehicle, which changes over time, can be calculated.

Now, assuming that the vehicle has traveled a certain distance and the number of pulses from the wheel rotation speed sensor is N, then L-α・N
...The following relational expression (1) is established. Here, α is a proportionality constant determined based on various parameters such as the number of pulses per rotation of the military transport and the diameter of the tire of the wheel.

By the way, the diameter of the tire changes due to changes in the air pressure of the tires used or changes in the weight of objects loaded on the car i, so the proportionality constant α is no longer constant, and its As a result, an error may occur in calculating the distance traveled by the vehicle, and the display of the current position of the vehicle on the display may deviate from the correct position.

To this end, in the conventional device described above, a distance correction mode is provided, as shown in the flowchart in FIG. 5, and an appropriate correction coefficient K is calculated and stored and registered in an appropriate storage means. Then, the desired travel distance is calculated using the following formula.

L=K-L (2) The distance correction mode will now be explained with reference to FIG. 5. At the time when the operation name of the i1j vehicle is located at a distance from the input means (45), is the correction mode specified? Then, the routine moves to the operator 111 routine (500), and the required operating procedure is displayed. Next, from a predetermined key of the input means (45), the amount of movement f't L to be traveled in the direction of correction is entered.
When inputted, the process moves to the mileage storage routine (501). Next, when the start of the correction operation is instructed by a predetermined key of the input means (45), a start routine (502
), the data corresponding to the travel distance l is transmitted to mII of a predetermined calculation means and stored in a suitable storage means. Next, the process moves to a ten-line distance measurement routine (503), and a number of pulse signals corresponding to the amount of movement of the vehicle are manually inputted from the movement amount sensor (.t:1). And fii
When the vehicle travels the planned travel distance 1- as shown in f, the input terminal rA/At+XMnGthn-+k
t,, m-4-L -yL,,,-'y"l-
This is identified in the hmlill routine (504), and the process moves to the correction coefficient calculation routine (505). Here, from the value (number of pulses) N detected in the distance measurement routine (503) and the planned travel distance, □
A correction coefficient K expressed by the following equation is calculated.

K = L/N (3) [Problem to be solved by the invention 1 Since the conventional vehicle navigation device is configured and operated as described above, The process of correcting the output signal is performed manually, and timing deviations may occur when starting or stopping a desired routine by pressing a predetermined key on the input means. In such a case, the calculated correction coefficients will include errors, and there is a problem in that the correction processing to improve the accuracy of the vehicle distance may actually have the opposite effect.

This invention was made to solve the above-mentioned problems, and provides a vehicle navigation device that can automatically and accurately correct the output signal from the vehicle's mileage sensor. Let's say 30 targets.

[Means for Solving the Problems] A vehicle navigation device according to the present invention includes: a direction sensor that detects the running direction of the vehicle; a mileage sensor that detects the roughness of the mileage; a sunlight sensor that detects the presence or absence of a tunnel section; an external storage device that stores road network data and map data for the vehicle; an operation key that inputs required operation instructions and required data; It consists of a central processing unit equipped with a CRT that displays the contents of the computer, an FLAM that temporarily stores various data, and a ROM that stores programs for various operations.

[Function] In the present invention, it is determined by the sunlight sensor whether or not the vehicle is running in a tunnel section, and when the vehicle is running in the tunnel section, the sunlight detected by the mileage sensor is Necessary correction processing is performed based on the travel distance corresponding to the I tunnel portion and the distance of the tunnel portion stored in the external storage device.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
FIG. 1 is a block diagram showing a schematic configuration of a vehicle navigation device that is an embodiment of the present invention. FIG. 2 is a functional block diagram functionally explaining the above embodiment.

FIG. 3 is a flowchart I diagram showing an example of the operation of the distance sensor correction process in the above embodiment.

First, in the first U2I, the central processing unit (1) performs necessary arithmetic processing on input signals from various sensors and keys, which will be described later, and displays the results on an appropriate display means. This central processing unit (1) has
The following means are provided f1. That is, a direction sensor (2), such as a geomagnetic sensor, which outputs a direction detection signal indicating the direction in which the vehicle is traveling; a mileage sensor (3), such as a wheel rotation speed sensor, A device that outputs a pulse signal proportional to the distance traveled by the vehicle; for example, a sunlight sensor such as a photodiode (4
), which changes the detection signal level according to the intensity of external light incident on the vehicle: for example, an external storage device such as a CD-ROM (5), in which predetermined road network data is stored. Various operation keys (6) necessary to operate this embodiment device, such as keys for registering the current position and destination position of the vehicle, and a scale for displaying a map of the target. Contains keys, etc. for setting; CRT (7) as a display means for displaying the vehicle's current position and corresponding map information; Based on signals from various sensors RAM (8) for temporarily storing data and data as calculation results by the central processing unit (1); This is a ROM (9) for storing programs.

Next, in FIG. 2, (10) is a position calculation means, which receives signals from a direction sensor (2) and a rough travel distance sensor (3), and from a travel distance correction means (14), which will be described later. It is used to receive signals and accurately calculate the current position of the vehicle. Reference numeral (11) denotes a map data storage means, which includes the external storage device (5) shown in FIG. 1 and the corresponding functional parts of the central processing unit (1). (12) is a display control means for causing the attached display means (13) to display a desired display by supplying information regarding the travel trajectory and current position of the vehicle and related map information. It is. Further, (14) is a mileage correction means, which calculates the signal from the mileage sensor (3) based on the signal from the sunlight sensor (4) and the map data from the map data storage means (11).
This is to calculate a certain predetermined hli positive coefficient from the entire long distance of the tunnel portion in the route on which both cars are traveling, and to perform the necessary correction on the signal from the 1F row distance sensor (3).

Here, the operation of the above embodiment will be explained with reference to FIGS. 1 to 3 as necessary.

It is now assumed that a vehicle is traveling along a required route during the daytime when the surroundings are sufficiently bright, and has entered a channel portion of the route. At this time, the sunlight sensor (4) changes from a "bright" state to a "dark" state.
An interrupt is made to the routine, and the interrupt subroutine corresponding to the state change starts (3
0). Next, a distance counter (not shown) provided separately for correction is reset (31), and a distance sensor (not shown) when the vehicle is traveling in a tunnel is reset (31).
3) is integrating the output pulses from (32). While performing this integration operation, the sunlight sensor (4)
It is periodically determined whether the state has changed to the "clear" state (33).

If the result of this determination is YES, the process moves to the next continuation (34), but if the result of the determination is NO, the process returns to (32).

Assuming that the vehicle has exited the tunnel at the point in time, since the determination result in (33) above is Yes,
Next, proceeding to (34), the cumulative content N of the distance counter is stored and registered at a predetermined address, for example, R, A M (8). Next, the map data storage means (11
), the long distance of the tunnel is read (35), and a required correction coefficient K as shown below is calculated (36) in the same format as the above equation (3).

K=L/N Thereafter, a return is made to the required step of the interrupted main routine (37).

That is, according to the embodiment of the present invention, when the vehicle passes through a tunnel while driving, the corresponding correction coefficient K is automatically obtained, so that the correction value may vary depending on the driver of the vehicle. Compared to conventional cases where this could occur,
The reliability and accuracy are greatly improved.

[Effects of the Invention] As explained above, the vehicle navigation device according to the present invention includes a direction sensor that detects the traveling direction of the vehicle, a travel distance sensor that detects the travel distance, and a vehicle navigation device that detects the travel direction of the vehicle. an external storage device storing road network data and map data for the vehicle; and operation keys for inputting required operation instructions and required data; A CRT that displays desired content and an R that temporarily stores various data.
AM and programs for various operations are stored (
The device is composed of a central processing unit equipped with a ROM, and the sunlight sensor determines whether the vehicle is traveling in a tunnel, and when the vehicle is traveling in the tunnel, the Since the necessary correction processing is performed based on the travel distance corresponding to the tunnel portion detected by the distance sensor and the distance of the I tunnel portion stored in the external storage device, the necessary processing can be performed manually. This method has the advantage that it is performed automatically and its accuracy is significantly improved compared to the conventional example in which the method was used.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a vehicle navigation device which is an embodiment of the present invention, FIG. 2 is a functional block diagram functionally explaining the above embodiment, and FIG. A flowchart diagram illustrating an example of the operation of the distance sensor correction process in the embodiment, FIG. 4 is a block diagram illustrating a conventional vehicle navigation device, and FIG. 5 is a flowchart illustrating the operation of the conventional example. It is a diagram. (1) is the central processing unit, (2) is the direction sensor, (3) is the mileage sensor, (4) is the sunlight sensor, (5) is the external storage device, (6) is the operation key, and (7) is the CRT. , (8) is RAM, (9) is ROM, (10) is position calculation means, (
11) is a map data storage means, (12) is a display control means, (13) is a display means, and (14) is a mileage correction means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A direction sensor that detects the running direction of the vehicle, a mileage sensor that detects the distance traveled, and a sunlight sensor that detects the presence or absence of a tunnel portion in the travel route of the vehicle;
an external storage device storing road network data and map data for the vehicle, operation keys for inputting required operation instructions and required data, and a CR for displaying desired contents.
T, RAM for temporarily storing various data,
A vehicle navigation device comprising a central processing unit equipped with a ROM that stores programs for various operations, the vehicle navigation device determining whether the vehicle is traveling in a tunnel portion using the sunlight sensor, When the vehicle is traveling in a tunnel section, the required distance is determined based on the mileage corresponding to the tunnel section detected by the mileage sensor and the distance of the tunnel section stored in the external storage device. A vehicle navigation device characterized in that a correction process is performed.