JPH06347277A - Navigation apparatus - Google Patents

Abstract

PURPOSE:To provide a navigation apparatus wherein the time which elapses until a navigation function is executed since a power supply is turned on can be reduced to a minimum. CONSTITUTION:A navigation ECU 2 is provided with a nonvolatile memory 2c which keeps a stored content even when a power supply is cut off. In addition, an external storage device 4 in which a program used to execute a navigation function has been stored is connected to the navigation ECU 4. The program which is read out by the navigation ECU 2 from the external storage device 4 is stored in the nonvolatile memory 2c. Once the program is read out, it is not required to read out the program. As a result, it is possible to provide a navigation apparatus which can start the execution of the navigation function from next time onward nearly simultaneously with the turning-on operation of a power supply and which is easy to use for a user.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device mounted on a mobile body and used to display the current position of the mobile body together with a road map around the current location.

[0002]

2. Description of the Related Art Conventionally, a function of displaying a current position of a vehicle together with a road map around the vehicle on a display device composed of a CRT or the like (hereinafter, referred to as " A navigation device having a "navigation function") is mounted on a vehicle and used. In this navigation device, the navigation function is generally executed according to a program stored in advance in a ROM (read-only memory) provided in the navigation device.

However, since this program is stored in advance in the read-only memory ROM, the user cannot change the program even if he / she wants to change it. Therefore, in order to solve this, there is a technique in which the user can easily change the program, for example, Japanese Patent Laid-Open No. 4-19
It is disclosed in Japanese Patent No. 5184. FIG. 8 is a block diagram briefly showing the configuration of the prior art disclosed in the above-mentioned publication. In this prior art, the control device 100 displays a current position measuring device 101 for detecting the current position of the vehicle, a CD-ROM 102 storing a program for realizing a navigation function, and the current position of the vehicle. The display device 103 is connected.

In this structure, when the power is turned on,
The RAM 100a provided in the control device 100 has a C
The program is read from the D-ROM 102 and stored. The CPU provided in the control device 100
The program stored in the RAM 100a is read by 100b and the navigation function is executed. That is, the current position of the vehicle detected by the current position measuring device 101 is displayed on the display device 103 together with the road map around the vehicle.

As described above, in the above-mentioned prior art, since the program is stored in the CD-ROM 102 which is an external storage device, the user stores this CD-ROM 102 in another CD.
-The program can be easily changed by replacing it with the ROM.

[0006]

In the above prior art, C
The program stored in the D-ROM 102 is RAM
It is stored in 100a. However, the RAM 100a is a volatile memory and its contents are erased when the power is turned off. Therefore, the program must be read from the CD-ROM 102 each time the power is turned on.

On the other hand, the time required from when the power is turned on to when the program is actually read and the navigation function is started to be executed based on the program is usually several tens of seconds to several minutes. That is, in the above-described prior art, the navigation function cannot be executed until at least several tens of seconds to several minutes elapse each time the power is turned on. Therefore, it is very inconvenient for the user.

Further, in the above prior art, the reading of the program is automatically started at the same time when the power is turned on. Therefore, the program cannot be selected. For this reason,
The program that can be stored in the CD-ROM 102 is limited to one type, and it is not possible to realize a multifunctional navigation device that reads the program for each function.

Therefore, an object of the present invention is to solve the above-mentioned technical problems, to easily change the program, and to minimize the time from turning on the power to executing the navigation function. It is to provide a device. Further, another object of the present invention is to
It is an object of the present invention to provide a navigation device capable of easily changing a program and selecting a program when there are a plurality of programs.

[0010]

A navigation device according to claim 1 for achieving the above object is mounted on a moving body for use, detects a current position of the moving body, and detects the detected current position. A navigation device having a function of displaying, together with a road map around it, external storage means for storing a program for realizing the function, reading means for reading the program from the external storage means, and the reading means. And a non-volatile main storage means for storing the program read by, and an execution means for executing the above function based on the program stored in the main storage means.

Further, the navigation device according to claim 2 further includes an error detecting means for detecting whether or not there is an error in the program stored in the main storage means, and the reading means includes the error detecting means. When the program stored in the main storage means is detected to have an error, the program is read from the external storage means and written in the main storage means.

According to a third aspect of the present invention, in the navigation device, the external storage means stores at least two or more programs in advance, and among the two or more programs stored in the external storage means. It is characterized in that it further comprises selection means for selecting a desired program. Further, the navigation device according to claim 4, when the error detecting unit detects that the program stored in the main storage unit has an error, the notifying unit notifies the user of the error. Is further included.

According to a fifth aspect of the present invention, in the navigation device, when the error detecting means detects that the program stored in the main storing means has an error, the reading means stores the program in the main storing means. Prior to the writing of the data, a determination means for determining whether or not the error can be corrected, and a correction means for correcting the error when the determination means determines that the error can be corrected are further included. It is what

A navigation device according to a sixth aspect of the invention is characterized in that the main storage means can switch between a writing mode and a read-only mode.

[0015]

According to the above-mentioned structure, the program is read from the external storage means by the reading means and stored in the non-volatile main storage means. Therefore, the program is retained even if the power is turned off. Therefore, once the program is read from the external storage means to the main storage means, the program can be used thereafter, and it is not necessary to newly read the program from the external storage means.
Therefore, the time required to read the program from the external storage means can be saved, and the time from power-on to the start of function execution can be minimized.

Further, in the configuration according to claim 2, the error detecting means detects whether or not there is an error in the program stored in the main storage means. As a result, when it is detected that there is an error, the program is read from the external storage means. In other words, the program is not read from the external storage means unless the program stored in the main storage means has an error. Therefore, the time required to read the program from the external storage means can be saved, and the time from power-on to the start of function execution can be minimized.

According to the third aspect of the invention, the desired program can be selected from the two or more programs stored in the external storage means. Therefore, a plurality of types of programs can be stored in the external storage unit in advance. Also, for example, if you select a different program when there is an error in the program,
The function can be executed more effectively.

Further, in the above-mentioned structure, when the error detecting means detects that the program stored in the main storage means has an error, the notification means informs the user of the error. Be informed. Therefore, the user
You can recognize that the program is incorrect.
If an error is recognized, the program can be changed to another program.

According to the fifth aspect of the invention, when the error detecting means detects that the program stored in the main storage means has an error, the main means for reading determines whether or not the error can be corrected. Before the writing of the program in the storage means, the judgment means makes a judgment. As a result, when it is determined that the error can be corrected, the error is corrected by the correction means.

As described above, in the above configuration, when the program has an error, the program is not always read from the external storage means, but the error is corrected when the program is correctable. I am trying to reduce the number of times the program is read. Therefore, the time required to read the program from the external storage means can be saved, and the time from power-on to the start of function execution can be minimized.

Further, in the structure according to the sixth aspect, the main storage means can switch between the write mode and the read-only mode. Therefore, by switching the main memory means to the read-only mode, it is possible to prevent the program stored in the main memory means from being destroyed even if the program runs out of control.

[0022]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram briefly showing the configuration of the navigation device according to the first embodiment of the present invention. This navigation device is used by being mounted on a vehicle, and includes a position detector 1 and a navigation EC.
Equipped with U2.

More specifically, the position detector 1 detects the current position of the vehicle, and is based on data obtained by integrating displacement amounts of outputs of a distance sensor and a direction sensor (not shown). The estimated position of the vehicle is calculated by dead reckoning, and the calculated estimated position is subjected to so-called map matching processing (see, for example, JP-A-63-148115 and JP-A-64-53112). , The current position is detected.

In this embodiment, the current position of the vehicle is detected using the output of each sensor as described above.
For example, the current position of the vehicle may be detected using a technique of measuring the propagation delay time of the radio wave transmitted from the GPS satellite and performing positioning. In addition, in addition to receiving radio waves transmitted from beacon transmitters installed on the roadside,
The current position of the vehicle may be detected based on the radio wave.

In the position detector 1, when the current position is detected, a road map around the current position is read from a road map memory (not shown), and the current position and the road map around it are stored in the navigation ECU 2. Is output. An external storage device 4 which is an external storage means is connected to the navigation ECU 2 via a CD drive 3. The external storage device 4 has a function of detecting the current position of the vehicle and displaying the current position together with a road map around the vehicle (hereinafter,
It is called "navigation function". ) Is stored in advance. Therefore, the user
The program can be changed easily.

Further, the navigation ECU 2 has a CR
A display device 5 composed of T or the like is connected via a graphic generator 6. Further, the navigation ECU 2 is connected with a changeover switch 7 for giving a signal for changing a nonvolatile memory described later between a write mode and a read only mode. Navigation ECU
2 executes a navigation function by reading the program from the external storage device 4 and storing the program in the navigation ECU 2. That is, the current position of the vehicle detected by the position detector 1 is displayed on the display device 5 together with the road map around it.

FIG. 2 is a block diagram briefly showing the internal structure of the navigation ECU 2. The navigation ECU 2 is a CPU (central processing unit) 2a that performs various controls, a fixed ROM 2b in which a basic program is stored in advance, and a non-volatile memory that is a main storage unit that stores a program read from the external storage device 4. Memory 2c,
It is composed of a RAM 2d for temporarily storing a program read from the external storage device 4. 2
e is an internal bus.

More specifically, the fixed ROM 2b
Is composed of, for example, an EPROM (rewritable ROM) or a mask ROM. The fixed ROM 2b includes, for example, a function for transferring a program from the external storage device 4 to the navigation ECU 2, that is, a program for a load function, a program for a function for transferring a program in the navigation ECU 2 (load function), and As a result of loading
A function for determining whether or not the file has been loaded without any abnormality, that is, a program related to the verify function is stored. In this embodiment, the fixed ROM 2b corresponds to a reading means, an executing means, an error detecting means, a judging means and a correcting means.

In the CPU 2a, the operation relating to the execution of the navigation function is controlled based on each program stored in the fixed ROM 2b. That is, for example, the CPU 2a loads the program from the external storage device 4 into the RAM 2d and temporarily stores the program based on the above program when the navigation device is used for the first time. The programs temporarily stored in the RAM 2d include error correction / detection codes such as cyclic redundancy code (CRC) and checksum. Therefore, from the external storage device 4 to RA
It is possible to perform a transfer error check when the program is loaded in the M2d, a program check on the nonvolatile memory 2c, and the like.

Further, the CPU 2a loads the program temporarily stored in the RAM 2d into the non-volatile memory 2c at a predetermined timing and stores the program based on the above program. The program once stored in the nonvolatile memory 2c remains stored even when the power is turned off. Therefore, after the second time, the nonvolatile memory 2
The navigation function can be executed using the program stored in c. Therefore, it is possible to save the time required for reading the program from the second time onward, and thus it is possible to minimize the time from the power-on to the start of the navigation function execution.

If the program stored in the non-volatile memory 2c is accidentally runaway, the program may be destroyed. Therefore, if the nonvolatile memory 2c is switched to the read-only mode by the changeover switch 7, it is possible to protect the destruction of the program due to runaway in hardware. Therefore, the probability that the program stored in the non-volatile memory 2c becomes abnormal can be reduced, and the number of times the program is loaded from the external storage device 4 can be reduced. Therefore, it is possible to minimize the time from when the power is turned on to when the execution of the navigation function is started.

In addition, the RAM 2d to the non-volatile memory 2c
A program for automatically switching the non-volatile memory 2c to the read-only mode after completion of the transfer of the program to the fixed ROM 2b may be stored in advance in the fixed ROM 2b. With such a configuration, the changeover switch 7 becomes unnecessary. FIG. 3 is a flowchart showing an operation when the navigation device is operated for the second time and thereafter. From the second time onward, the program for realizing the navigation function is already stored in the non-volatile memory 2c. However, the program stored in the non-volatile memory 2c is not always accurate. Therefore, first, it is determined whether or not there is an error in the program stored in the nonvolatile memory 2c (step S1). The criterion at this time is an error correction / detection code such as a cyclic redundancy code included in the above-mentioned program.

As a result of the above judgment, if it is judged that the program has no error, the normal navigation function is executed according to the program (step S2). On the other hand, when it is determined that the program has an error, it is determined whether or not the error can be corrected (step S
3). As a result, if it is determined that the error can be corrected, the error is corrected and the normal navigation function is executed (steps S4 and S2). If it is determined that the error cannot be corrected, the external storage device 4 stores the data in the RAM 2d. The program is loaded (step S5).

That is, when the error can be corrected, the error is corrected to reduce the number of times the program is loaded from the external storage device 4 to the navigation ECU 2. Therefore, as long as there is no error in the program stored in the nonvolatile memory 2c, the program can be used to execute the navigation function.
It is possible to minimize the time from turning on the power to starting the execution of the navigation function.

When the program is loaded from the external storage device 4 to the RAM 2d, it is determined based on the above program whether or not the loaded program has an error (step S6). That is, the transfer error is checked. This transfer error is checked because an error is likely to occur during the loading of the program because the physical distance from the external storage device 4 to the RAM 2d.

If it is determined in step S6 that the program has no error, it is determined that the program has been normally loaded, and the program is loaded and stored in the nonvolatile memory 2c (step S9). . Then, thereafter, the normal navigation function is executed according to the program stored in the non-volatile memory 2c (step S2).

On the other hand, if it is determined in step S6 that the program loaded from the external storage device 4 has an error, it is determined whether or not the error can be corrected (step S7). If it is determined that it can be corrected, the error is corrected (step S8), and then the normal navigation function is executed (step S2).
On the contrary, if it is determined that the correction is impossible, the program is reloaded.

FIG. 4 is a flow chart showing the control operation in the navigation device of the second embodiment of the present invention, and FIG. 5 is a front view showing the display screen of the display device 5. Although only one program is stored in the external storage device 4 in the first embodiment, a plurality of programs may be stored. However, in this case, it is not so effective unless a desired program can be selected from the plurality of programs. Therefore, in the second embodiment, a selection operation when a plurality of programs are stored in the external storage device 4 will be described with reference to FIGS. 4 and 5.

When the user wants to select a desired program, a menu screen as shown in FIG. 5A is displayed on the display device 5 by operating an operation button or the like provided in an appropriate place of the display device 5 ( Step P1). Then, by touching the "program update" key 11 on the screen, a load program selection screen as shown in FIG. 5 (b) is displayed on the display device 5 (step P
2). Then, press any key 12 from the "program name" keys 12 on the load program selection screen.
Touch to select the desired program (for example, "Program name 1".). That is, the program update key 11 and the program name key 12 correspond to selecting means.

When a specific program name is selected by the user, the operation thereafter is the same as in the first embodiment, loading the program from the external storage device 4 to the RAM 2d (step P3) and executing the program. Error / correction detection (steps P4, P5), error correction (step P
After 6) and the like are performed, the program is loaded and stored in the nonvolatile memory 2c (step P7), and the normal navigation function is executed (step P8).

As described above, according to the navigation device of the second embodiment, the user can select a desired program from a plurality of programs, so that a multifunctional navigation device can be realized. Figure 6
[Fig. 7] is a flowchart showing a control operation in the navigation device of the third embodiment of the present invention, and Fig. 7 is a front view showing a display screen of the display device 5. This embodiment is a combination of the operations of the first and second embodiments.

First, it is judged whether or not there is an error in the program stored in the non-volatile memory 2c (step N1). As a result, if there is no error, a normal navigation function is executed (step N2), and an error occurs. If there is, it is judged whether or not the error can be corrected (step N).
3). As a result, if it is correctable, the error is corrected (step N4), and the normal navigation function is executed. On the other hand, if it cannot be corrected, the nonvolatile memory 2c
In order to inform the user that there is an error in the program stored in the display device 5, as shown in FIG.
The abnormality warning screen is displayed on the screen (step N5). This allows the user to recognize that the program has an error.

When the user visually recognizes this abnormality warning screen,
In order to change to another program that does not have an error, "Program load" displayed on the error warning screen shown in Fig. 7 (a).
Touch the key 21 to display the load program selection screen shown in FIG. 7B on the display device 5 (step N
6). Then, a program other than the erroneous program is selected, and the "program name" key 22 is touch-operated (for example, "program name 1").

When a specific program is selected by the user, the subsequent operation is the same as in the first embodiment described above.
Loading a program from the external storage device 4 (step N
7), error / correction detection of the program (step N
8, N9), error correction (step N10), etc., and then the program is loaded and stored in the non-volatile memory 2c (step N11), and the normal navigation function is executed.

Although the embodiments have been described above, the present invention is not limited to the above-mentioned embodiments, and various design changes can be made without changing the gist of the present invention. .

[0046]

As described above, according to the navigation device of the present invention, since the program for realizing the function is stored in the external storage means, the user can change the program. Further, since the program read from the external storage means is stored in the non-volatile main storage means, the number of times the program is read can be significantly reduced. Therefore, it is possible to minimize the time from power-on to the start of function execution. Therefore,
It is possible to provide a navigation device that is very easy for the user to use.

In particular, according to the navigation device of the second aspect, the program is read from the external storage means only when the program stored in the main storage means has an error. It can be reduced significantly. Therefore, it is possible to provide a navigation device that is easier for the user to use. Further, according to the navigation device of the third aspect, the program can be selected by the user, so that a multifunctional navigation device can be provided.

According to the navigation device of the fourth aspect, the user is informed that the program stored in the main storage means has an error, so that the user can easily take a subsequent action. That is, it is possible to provide a navigation device that is easy for the user to use. Also,
According to the navigation device of the fifth aspect, even if the program stored in the main storage means has an error,
If the error can be corrected, the number of times the program is read can be further reduced by correcting it. Therefore, it is possible to provide a navigation device that is very easy for the user to use.

Further, according to the navigation device of the sixth aspect, the main storage means can be switched to the read-only mode, so that even if a program runaway occurs accidentally, the program runaway is prevented from being destroyed. be able to. Therefore, it is possible to provide a navigation device that is very easy for the user to use.

[Brief description of drawings]

FIG. 1 is a block diagram briefly showing a configuration of a navigation device according to an embodiment of the present invention.

FIG. 2 is a block diagram briefly showing an internal configuration of a navigation ECU.

FIG. 3 is a flowchart showing an operation when the navigation device according to the first embodiment of the present invention is used for the second time and thereafter.

FIG. 4 is a flowchart showing an operation of the navigation device according to the second embodiment of the present invention.

FIG. 5 is a front view showing a display screen of a display device in the second embodiment.

FIG. 6 is a flowchart showing the operation of the navigation device according to the third embodiment of the present invention.

FIG. 7 is a front view showing a display screen of a display device in the third embodiment.

FIG. 8 is a block diagram showing a configuration of a conventional navigation device.

[Explanation of symbols]

 1 Position Detector 2 Navigation ECU 2a CPU 2b Fixed Memory 2c Nonvolatile Memory 4 External Storage Device 5 Display Device 7 Changeover Switch 11 Program Update Key 12, 22 Program Name Key 21 Program Load Key

Claims (6)

[Claims] 1. A navigation device mounted on a mobile body, used to detect the current position of the mobile body, and to display the detected current position together with a road map around the navigation device. An external storage unit that stores a program for executing the program, a reading unit that reads the program stored in the external storage unit, and a program that is read by the reading unit.
A navigation device comprising: a non-volatile main storage means; and an execution means for executing the above function based on a program stored in the main storage means. 2. The apparatus further comprises error detecting means for detecting whether or not there is an error in the program stored in the main memory means, and the reading means is stored in the main memory means by the error detecting means. 2. The navigation device according to claim 1, wherein when it is detected that the existing program has an error, the program is read from the external storage means and written in the main storage means. 3. The external storage means stores at least two or more programs in advance, and a selection means for selecting a desired program from the two or more programs stored in the external storage means. The navigation device according to claim 2, further comprising: 4. When the error detection means detects that the program stored in the main storage means has an error, the error detection means further includes notification means for informing the user of the error. The navigation device according to claim 2 or 3. 5. When the error detection means detects that the program stored in the main storage means has an error, the error is detected prior to the writing of the program into the main storage means by the reading means. 5. The method according to claim 2, further comprising: a judging means for judging whether or not the error can be corrected, and a correcting means for correcting the error when it is judged by the judging means that the error can be corrected. The described navigation device. 6. The main storage means is capable of switching between a write mode and a read-only mode.
Navigation device according to 2, 3, 4 or 5.