JPH06215295A - Navigation device - Google Patents

Abstract

PURPOSE:To surely write the positional data of a vehicle in a non-volatile memory from a vehicle position detecting means even when the key switch of a vehicle is turned off without depressing a power supply cut-off switch. CONSTITUTION:When a vehicle is traveled, a vehicle position detecting means 10 adds a value obtained by sequentially integrating vehicle speeds detected by a vehicle speed detecting means 9 to the initial value of vehicle positional data, detects the current position of the vehicle and displays the current position on a display means 11. When the means 9 detects that the vehicle speed is dropped less than a certain value, e.g. 10m/hour, on the way of traveling or at the time of stopping the traveling, the vehicle position data detected by the means 10 are written in the non-volatile memory 8. Even if the vehicle key switch is turned off erroneously before depressing the power supply cut-off switch 6, the vehicle position data detected by the means 10 are without fail written in the memory 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device for informing a driver or the like of the current position of a vehicle.

[0002]

2. Description of the Related Art In recent years, GPS (Global Positioning S)
With the improvement of atelite), various navigation devices for cars have been developed.

The power supply circuit of a conventional navigation device is
When the power cutoff switch is pressed, the method of writing the data, especially the last measured vehicle position data in the non-volatile memory and shutting off the power by the power supply control means to back up is generally adopted.

[0004]

However, when a navigation device that connects to a power source through a cigar socket is installed in a vehicle in which the power supply from the power source to the cigar socket is cut off when the key switch is turned off, the power supply is cut off. If the key switch is turned off before pressing the switch, the vehicle position data will not be written from the vehicle position detection means to the non-volatile memory. There has been a problem in that it has to be newly written in the vehicle position detecting means, which makes handling very troublesome.

In order to solve this problem, there is also a method of rewriting the vehicle position data stored in the non-volatile memory every time the vehicle position detecting means detects the position of the vehicle. However, since the rewriting interval must be as short as possible, in other words, the rewriting frequency must be increased, there is a problem that an EEPROM or the like having a limited number of rewriting cannot be used as the nonvolatile memory of the navigation device.

The present invention has been made in view of such a problem. Even if the key switch of the vehicle is turned off without pressing the power cutoff switch, the vehicle position data is non-volatile from the vehicle position detecting means. It is an object of the present invention to provide a navigation device that is surely written in a memory.

[0007]

According to the present invention, when the vehicle speed detecting means detects that the traveling speed of a vehicle has dropped below a certain value,
Backup data such as vehicle position data is written in a non-volatile memory.

[0008]

According to the present invention, even if the key switch of the vehicle is accidentally turned off before the power cut-off switch is pressed, the vehicle position data detected by the vehicle position detecting means is set immediately before the vehicle stops traveling. Since the data is written in the non-volatile memory, it is not necessary to write the initial value of the vehicle position data, the setting data, etc. from the input means to the vehicle position detection means when the power source is subsequently turned on, and the handling is very easy. Become.

Further, since the vehicle position data detected by the vehicle position detecting means is written into the non-volatile memory only immediately before the vehicle stops traveling, the frequency of rewriting the vehicle position data is extremely reduced, and the number of times of rewriting is reduced. Limited to EEPRO
M or the like can be used as a nonvolatile memory of the navigation device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a configuration of an embodiment of the present invention. 1 is a CPU for controlling a navigation device, 2 is a ROM storing a control program for the CPU 1, and 3 is a CP.
The RAM 4 used for controlling U1 immediately turns on the power when the power-on switch 5 is pressed, and when the CPU 1 outputs the power-off command by pressing the power-off switch 6, the power-supply control means , 7 is an input means for inputting initial values of vehicle position data, setting data, etc. by a key or the like. The initial values of vehicle position data input by the input means 7 are, for example, latitude and longitude (degrees, minutes, Seconds) coordinates.

A non-volatile memory 8 stores various kinds of data such as vehicle position data, passing locus data, setting data (passing points, destinations, etc.). , Continue to store the written data.
9 is a vehicle speed detecting means for detecting the vehicle speed from the rotation of the wheels, 10
Is a vehicle position detection for detecting the position of the vehicle by adding a value obtained by integrating the vehicle speed detected by the vehicle speed detection means 9 every predetermined time to the initial value of the vehicle position data read from the non-volatile memory 8. Means 11 is a display means for displaying the vehicle position, vehicle speed, operation guidance and the like.

In this embodiment thus constructed, when the key switch of the vehicle is turned on and the power-on switch 5 is depressed, the power supply control means 4 turns on the power and the initial value of the vehicle position data is changed. Non-volatile memory 8 to vehicle position detection means 10
Written in. At this time, if the initial value of the vehicle position data written in the vehicle position detecting means 10 and the actual position of the vehicle are different, the initial value of the vehicle position data corresponding to the actual position of the vehicle is input means. Write from 7 into the vehicle position detecting means 10.

Then, when the vehicle is made to travel, the vehicle position detecting means 10 adds the value obtained by successively integrating the vehicle speed detected by the vehicle speed detecting means 9 to the initial value of the vehicle position data and adding the current value of the vehicle. The position is detected and then displayed on the display means 11.

Further, during or while the vehicle is traveling,
When the vehicle speed detecting means 9 detects that the speed of the vehicle has become a certain value or less, for example, 10 m / hour or less, the vehicle position data detected by the vehicle position detecting means 10 is written in the nonvolatile memory 8.

When the power cutoff switch 6 is depressed, the position of the vehicle detected by the vehicle position detection means 10 is written into the non-volatile memory 8 and then the CPU 1 outputs a power cutoff command to cause the power supply control means 4 to supply the power. Shut off.

Before pressing the power cutoff switch 6,
Even if the key switch of the vehicle is accidentally turned off, the vehicle position data detected by the vehicle position detecting means 10 is written in the non-volatile memory 8 immediately before the vehicle stops traveling, and is backed up. At some times, writing of backup data such as initial values of vehicle position data and setting data from the input means 7 to the vehicle position detection means 10 is completely unnecessary. That is, the time for writing the backup data to the non-volatile memory is sufficiently shorter than the time for stopping the running of the vehicle and turning off the key switch of the vehicle.

In this embodiment, the method of integrating the speed of the vehicle detected by the vehicle speed detecting means 9 to detect the current position of the vehicle has been described as an example, but the detected current position of the vehicle is differentiated. Then, the same method can be performed by the method of detecting the vehicle speed or the method of detecting the position and the vehicle speed independently.

In the navigation device for directly detecting the position, it seems seemingly meaningless to back up the position data of the vehicle detected by the vehicle position detecting means.
In the recent GPS-based position detection method, in order to reduce the position measurement time, the approximate current position of the vehicle must first be known. Therefore, the position data of the vehicle is non-volatile just before the vehicle stops traveling. Writing to memory is important.

Further, in the non-volatile memory 8, data other than the position data of the vehicle, for example, the data of the destination, the passing point, the trajectory of the vehicle, etc. may be written.

[0020]

As described above, according to the present invention,
Even if the key switch of the vehicle is accidentally turned off before the power cutoff switch is pressed, the vehicle position data detected by the vehicle position detection means is written in the nonvolatile memory immediately before the vehicle stops traveling. When the power is subsequently turned on, there is no need to write the initial value of the vehicle position data, the setting data, etc. from the input means to the vehicle position detection means, and there is an effect that handling is very simple.

Further, the position data of the vehicle detected by the vehicle position detecting means is written into the non-volatile memory only immediately before the vehicle stops traveling, so that the frequency of rewriting the position data of the vehicle becomes extremely low, and the number of times of rewriting is reduced. Limited to EEPRO
It is possible to use M or the like as a non-volatile memory of the navigation device.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

8 ... Non-volatile memory, 9 ... Vehicle speed detecting means, 10 ... Vehicle position detecting means.

Claims (3)

[Claims] 1. A vehicle speed detecting means for detecting a traveling speed of a vehicle, and a non-volatile memory which continues to store written backup data even when power is cut off. When the vehicle speed detection means detects that the above has occurred, the navigation device writes the backup data in the non-volatile memory. 2. A vehicle speed detecting means for detecting the traveling speed of the vehicle, and a value obtained by integrating the traveling speed of the vehicle detected by the vehicle speed detecting means in addition to the initial value of the position data of the vehicle, and the position of the vehicle. A vehicle position detecting means for detecting the vehicle speed, and a non-volatile memory that continues to store the written data even when the power is cut off. When it is detected, at least the data of the position of the vehicle is written from the vehicle position detecting means to the non-volatile memory. 3. A vehicle position detecting means for detecting a traveling position of the vehicle, a vehicle speed detecting means for differentiating the traveling position of the vehicle detected by the vehicle position detecting means to detect a traveling speed of the vehicle, and a power source. When the vehicle speed detecting means detects that the traveling speed of the vehicle has become equal to or lower than a certain value, it has at least the position data of the vehicle. The navigation device is characterized by writing in a non-volatile memory.