JP2004294151A - Navigation device, method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device, a method and a program capable of writing data surely by utilizing a nonvolatile memory. <P>SOLUTION: When intending to write data in a disc control part 12, if the disc control part 12 is reading data, a temporary storage part 45 stores temporarily data to be written in a SRAM 7 which is a nonvolatile memory. At the point of time when writing in the disc control part 12 becomes possible, a finish part 46 writes the data stored temporarily in the SRAM 7 in the disc control part 12. When a power source is switched off in the write waiting state, a start confirmation part 47 detects the effect when the power source is switched on next. When switch-off of the power source in the write waiting state is detected by the start confirmation part 47, the finish part 46 writes the data stored temporarily in the SRAM 7 in the disc control part 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a navigation device, a method, and a program for reliably writing data by using a nonvolatile memory.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the spread of automobiles and the progress of digital technology, navigation technology is rapidly spreading. In navigation, on-board devices and other devices use road map data to sequentially detect the position of the vehicle using GPS or the like and display it on a surrounding map, search for the optimal guidance route to a specified destination, and Along the route, guidance is provided by screen display, synthesized voice, and the like.
[0003]
In early navigation systems, key data such as road map data and data for searching for facilities and the like are recorded in a read-only, non-writable storage device such as a CD-ROM or DVD-ROM, and recorded ex post facto such as a registered location. The desired data has been recorded in a nonvolatile memory such as an SRAM. Since such a non-volatile memory has a small capacity, it is necessary to replace the recording medium itself such as a CD-ROM when it is necessary to add a relatively large capacity of information such as additional road map data.
[0004]
After that, due to the miniaturization of the storage means and the price reduction, the readable and writable storage means is mounted on the navigation device as typified by a hard disk drive (also simply referred to as “hard disk” or “HDD”). In other words, various kinds of information such as additional information such as road map data and search data have been recorded on HDDs (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2002-365063
[0006]
[Problems to be solved by the invention]
However, when the readable and writable storage means is used as described above, there is a problem that even if an attempt is made to write some information, writing may not be performed at the same time because, for example, road map data is being read. In particular, when the power is turned off by operating the ignition key of the vehicle while the writing is not performed and the writing is awaited, there is a problem that data to be recorded is not actually recorded.
[0007]
SUMMARY OF THE INVENTION The present invention solves the above-described problems of the related art, and an object of the present invention is to provide a navigation device, a method, and a program that reliably write data by using a nonvolatile memory.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, there is provided a navigation apparatus provided with a storage unit capable of writing and reading data, wherein when the storage unit attempts to write data into the storage unit, the storage unit reads the data. In the meantime, means for temporarily storing data to be written in a non-volatile memory, and when the writing to the storage means becomes possible, the data temporarily stored in the non-volatile memory And completion means for writing to the storage means.
[0009]
The invention according to claim 3 captures the invention according to claim 1 from the viewpoint of a method. In a navigation method using a storage unit capable of writing and reading data, when writing data to the storage unit, When the storage unit is reading data, a process of temporarily storing data to be written in the non-volatile memory, and when the writing to the storage unit becomes possible, the data is temporarily stored in the non-volatile memory. And a completion process of writing the stored data to the storage means.
[0010]
According to a fifth aspect of the present invention, the invention of the first and third aspects is grasped from the viewpoint of a computer program, and a navigation program for performing navigation by controlling a computer having a storage unit capable of writing and reading data. The program causes the computer to tentatively store the data to be written in a non-volatile memory when the storage means is reading data when trying to write data to the storage means, and to the storage means The data temporarily stored in the non-volatile memory is written to the storage means when writing of the data becomes possible.
[0011]
In these embodiments, when data writing to a readable / writable storage unit such as a hard disk cannot be performed immediately because data such as road map data is being read, data is temporarily written to a non-volatile memory, and then the data becomes writable. Then, writing is performed from the nonvolatile memory to the storage means. Therefore, the reliability of data writing is improved.
[0012]
According to a second aspect of the present invention, in the navigation device according to the first aspect, when the power supply is turned off in a write waiting state before the data temporarily stored in the nonvolatile memory is written to the storage unit, Detecting means for detecting when the power is turned on, wherein the completion means temporarily stores the power in the non-volatile memory when the detecting means detects that the power is turned off in the write waiting state; And writing the data stored in the storage means to the storage means.
[0013]
According to a fourth aspect of the present invention, there is provided the navigation method according to the third aspect, wherein the data temporarily stored in the non-volatile memory is written to the storage means. In the case where the power is turned off in the write waiting state, the processing includes a detection process for detecting the next time the power is turned on, and the completion process includes that the power is turned off in the write waiting state. When the data is detected by the detection process, the data temporarily stored in the nonvolatile memory is written to the storage unit.
[0014]
The invention of claim 6 captures the invention of claims 2 and 4 from the viewpoint of a computer program. In the navigation program according to claim 5, the program is temporarily stored in the computer and in the nonvolatile memory. When the power is turned off in a write waiting state before writing the stored data to the storage means, when the power is turned on next time, that fact is detected, and the power is turned off in the write waiting state. Is detected, the data provisionally stored in the non-volatile memory is written to the storage means.
[0015]
In these modes, even if the power is turned off by an ignition key operation or the like while the read / write storage unit such as a hard disk is reading data, the data is temporarily stored in the non-volatile memory, and the power is turned off by an ignition key operation or the like. When the writing is completed, the writing to the storage means is completed, thereby preventing unexpected loss of data to be stored.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention (hereinafter, referred to as “embodiments”) will be specifically described with reference to the drawings. Note that the present embodiment can be realized by controlling a computer with a program. However, in this case, the way of realizing the hardware and the program can be variously changed, and therefore, in the following description, each of the present invention and the present embodiment will be described. A virtual circuit block that realizes a function is used.
[0017]
[1. Hardware configuration)
The present embodiment shows a navigation device (hereinafter referred to as “this device”) of the present invention, and can be grasped as a method, a program, and a recording medium on which such a program is recorded. It is also an aspect of the present invention to download and execute the navigation system of each vehicle via a communication network such as a telephone network.
[0018]
[1-1. overall structure〕
First, the present apparatus is a navigation apparatus that performs navigation processing using a hard disk drive (HDD) that is a storage unit for readable and writable information, and includes the following elements shown in the functional block diagram of FIG. In other words, the absolute position / azimuth detecting unit 1 calculates, for example, the absolute position coordinates and the azimuth on the ground surface of the current position of the vehicle (referred to as the own vehicle) on which the apparatus is mounted, that is, , For receiving GPS radio waves transmitted from GPS satellites with an antenna or a receiver. The relative azimuth detecting unit 2 is a part for detecting the relative azimuth of the own vehicle using a gyro or the like. The vehicle speed detection unit 3 is a part that calculates the speed of the own vehicle by processing a vehicle speed pulse obtained from the vehicle.
[0019]
The main CPU and its peripheral circuit 4 are parts that serve as a control circuit for controlling the entire device. The memory group M is various memories necessary for the operation of the apparatus. For example, the ROM 5 for storing programs stores a BIOS and a boot program in advance, and is accessed by the main CPU when the apparatus is started. A main program is loaded into a dynamic RAM (DRAM) 6 which provides a work area and the like. The SRAM (static RAM) 7 is a storage unit for storing information such as various settings and flags. The battery is backed up even when the main power is off, and provides memory contents when the main power is turned on. However, it can be replaced by another type of storage means such as a flash memory. A display VRAM (video RAM) 8 stores bitmap data of an image to be displayed on the display unit 10.
[0020]
The display unit 10 is a part for displaying various information such as a map and an operation menu on a liquid crystal display screen (not shown), and is desirably used together with speech synthesis. The input unit 11 is a part for the user to input information such as a command from a key switch or the like, and includes a touch sensor function, a remote control unit, an infrared transmitting / receiving unit, and the like. The user interface unit 9 is a user interface that connects the display unit 10 and the input unit 11 to the main CPU and its peripheral circuits 4 using an I / O control circuit, a device driver, and the like. The disk control unit 12 is a hard disk drive that is a storage unit capable of writing and reading data, and stores road map data, search data for facilities, and the like, and additional data.
[0021]
The FM multiplex reception and processing unit 13 is a part that receives FM broadcast waves and performs processing such as extracting desired data such as traffic information of a VICS service from the broadcast waves.
[0022]
[1-2. Role of main CPU and its peripheral circuits]
Further, the main CPU and its peripheral circuit 4 are configured to realize the role of each of the following parts shown in FIG. That is, the current position detection unit 40 is means for sequentially calculating the own vehicle position, and specifically, is configured to calculate the vehicle position by combining GPS navigation positioning and autonomous navigation positioning.
[0023]
Here, in the GPS navigation positioning, the current position is calculated using information obtained by the absolute position / azimuth detecting unit 1 based on radio waves from artificial satellites. In the autonomous navigation positioning, the current position is calculated using information obtained from the relative azimuth detecting unit 2 and the vehicle speed detecting unit 3 based on the geomagnetism and the speed of the own vehicle.
[0024]
The destination specification unit 41 is a unit that receives an input of a destination by searching for a facility from a database or specifying a cursor on a map, and the route setting unit 42 determines a route to the input destination by the route. This is a means for calculating based on road map data or entrusting calculation to a predetermined server via communication, and setting the resulting route. In addition, the map display unit 43 displays the vehicle position on a surrounding map and at least a part of the route on the display unit 10 based on the calculated vehicle position and the road map data on the display unit 10 by three-dimensional display or other processing. The guidance control unit 44 is a unit that determines a part to be displayed in the route and elements such as blinking emphasis, and controls the guidance by using a combined voice.
[0025]
In addition, the main CPU and its peripheral circuit 4 play the role of each unit that operates as follows by the operation of the program described above.
[0026]
[2. Action)
That is, if the disk control unit 12 is reading data when trying to write data to the disk control unit 12, the temporary storage unit 45 temporarily stores the data to be written in the SRAM 7, which is a nonvolatile memory. The completion unit 46 writes the data temporarily stored in the SRAM 7 to the disk control unit 12 when the writing to the disk control unit 12 becomes possible.
[0027]
Here, the SRAM 7 is independent and independent of the disk cache memory provided in the hard disk drive unit, and its contents are retained after the power is once turned off until the next power on. That is, when the power is turned off in a write waiting state before the data temporarily stored in the SRAM 7 is written to the disk control unit 12, the activation confirmation unit 47 determines that the next time the power is turned on. Upon detection, the completion unit 46 writes the data provisionally stored in the SRAM 7 to the disk control unit 12 when the startup confirmation unit 47 detects that the power has been turned off in the write waiting state.
[0028]
Here, FIG. 2 is a flowchart of a process of writing data to the disk control unit 12. That is, in this procedure, when there is a data write request (step 1), the temporary storage unit 45 determines whether the disk control unit 12 is currently reading data (step 2). At this time, if the data is not being read by the disk control unit 12, the data to be written is written to the hard disk of the disk control unit 12 as it is (step 6).
[0029]
On the other hand, when the disk control unit 12 is reading data (step 2), the temporary storage unit 45 tentatively writes data in the SRAM 7, which is a non-volatile memory (step 3), and sets the write waiting flag to indicate that the writing is waiting. "1" is set (step 4), and this flag is also recorded in the SRAM 7. After the data is tentatively written in the nonvolatile memory SRAM 7 and the reading state of the disk control unit 12 is released (step 5), the completion unit 46 writes the data tentatively written in the nonvolatile memory SRAM 7 Writing to the hard disk of the control unit 12 (step 6), and if the write waiting flag = 1 after writing (step 7), the corresponding data in the nonvolatile memory SRAM 7 is deleted (step 8) and the flag is initialized to 0. (Step 9).
[0030]
Next, FIG. 3 is a flowchart of a data write-back process executed only once at the time of initial startup when the power of the apparatus is turned on. In FIG. 2, since the disk control unit 12 is reading data, the data is written to the nonvolatile memory SRAM 7 and a flag is set (steps 3 and 4) in FIG. 2, and then the data is written to the hard disk of the disk control unit 12. This is meaningful when the power is turned off before the flag is initialized to 0 (steps 6 to 9).
[0031]
That is, if the write waiting flag is “1” when the power is turned on (step 15), the startup check unit 47 determines that there is data provisionally written in the nonvolatile memory SRAM 7. The data is written to the hard disk of the disk controller 12 (step 16), the corresponding data in the nonvolatile memory SRAM 7 is deleted (step 18), and the write waiting flag is initialized to "0" (step 19).
[0032]
[3. effect〕
As described above, in the present embodiment, when data writing to a readable / writable storage unit such as a hard disk cannot be performed immediately because road map data or the like is being read, data is temporarily written to the nonvolatile memory, and then written. When it becomes possible, writing is performed from the nonvolatile memory to the storage means. Therefore, the reliability of data writing is improved.
[0033]
Further, in the present embodiment, since the readable and writable storage means such as a hard disk is reading data, even if the power is turned off by an ignition key operation or the like while the data is provisionally stored in the non-volatile memory in a waiting state for writing, the next power supply is performed. Since writing to the storage means is completed when is turned on, unexpected loss of data to be stored is prevented.
[0034]
[4. Other embodiments]
The present invention is not limited to the above embodiment, but includes other embodiments as exemplified below. For example, the information storage means is not limited to a hard disk drive, but can be replaced with a drive such as a DVD-RAM, DVD-RW or CD-RW, or various flash memory cards.
[0035]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a navigation device, a method, and a program that reliably write data by using a nonvolatile memory.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a flowchart showing a data write process according to the embodiment of the present invention.
FIG. 3 is a flowchart showing data write-back processing at the time of initial startup in the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Absolute position / azimuth detection part 2 ... Relative azimuth detection part 3 ... Vehicle speed detection part 4 ... Main CPU and its peripheral circuit M ... Memory group 5 ... ROM
6 ... DRAM
7 ... SRAM
8 ... VRAM
9 User interface unit 10 Display unit 11 Input unit 12 Disk control unit 13 FM multiplex reception and processing unit 14 Optical / beacon reception and processing unit M Memory group 40 Current position detection unit 41 Destination designation Unit 42 Route setting unit 43 Map display unit 44 Guidance control unit 45 Temporary storage unit 46 Completion unit 47 Start-up confirmation unit

Claims (6)

In a navigation device provided with a storage unit capable of writing and reading data,
Means for temporarily storing data to be written in a non-volatile memory if the storage means is reading data when trying to write data to the storage means;
Completion means for writing the data tentatively stored in the nonvolatile memory to the storage means at the time when writing to the storage means becomes possible,
A navigation device comprising: If the power supply is turned off in a write waiting state before writing the data provisionally stored in the nonvolatile memory to the storage means, detection means is provided for detecting that when the power supply is next turned on. ,
The completion unit is configured to write the data provisionally stored in the nonvolatile memory to the storage unit when the detection unit detects that the power is turned off in the write waiting state. The navigation device according to claim 1, wherein: In a navigation method using storage means capable of writing and reading data,
If the storage unit is reading data when trying to write data to the storage unit, processing to temporarily store the data to be written in the nonvolatile memory;
At the time when writing to the storage unit becomes possible, a completion process of writing the data temporarily stored in the nonvolatile memory to the storage unit,
A navigation method comprising: In the case where the power is turned off in a write waiting state before writing the data provisionally stored in the nonvolatile memory to the storage means, when the power is turned on next, a detection process for detecting the power off is included. ,
In the completion process, when it is detected by the detection process that the power is turned off in the write waiting state, the data temporarily stored in the nonvolatile memory is written to the storage unit. The navigation method according to claim 3. In a navigation program for performing navigation by controlling a computer having a storage unit capable of writing and reading data,
The program is stored on the computer
If the storage means is reading data when trying to write data to the storage means, the data to be written is temporarily stored in a non-volatile memory,
A navigation program wherein the data temporarily stored in the non-volatile memory is written to the storage means when the writing to the storage means becomes possible. The program is stored in the computer,
If the power is turned off in a write waiting state before writing the data tentatively stored in the nonvolatile memory to the storage means, when the power is turned on next, the fact is detected,
6. The navigation program according to claim 5, wherein when it is detected that the power is turned off in the write waiting state, the data temporarily stored in the nonvolatile memory is written to the storage unit.

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