JP2009229224A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device which solves a problem that since there has not been a means so far for clearly notifying a user of a fact that a GPS receiver cannot perform detection of a position, the user cannot obtain information about its clue, even when the user desires to use accurate information about a present position, and which has a display means to afford a clue for knowing reliability of displayed information on the present position. <P>SOLUTION: The navigation device having a GPS reception means performs different display according to a duration of a non-positioning state in which a position detecting process cannot be performed by the GPS reception means. In addition, the navigation device also displays the duration of the non-positioning state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a navigation device mounted on a vehicle or the like, and more particularly, to a navigation device configured so that the reliability of displayed current position information can be easily grasped.

In the past, navigation devices mounted on moving bodies such as automobiles have used position detection means based on self-contained navigation provided with a gyro (compass), an acceleration sensor, etc. In recent years, navigation devices using GPS positioning information. Has become the mainstream. After that, positioning accuracy has also been improved, and those equipped with functions such as searching for the fastest route to the destination and predicting the time required for arrival are provided.
In general, the self-contained navigation positioning means can detect the position of the own vehicle with a relatively simple device configuration based on the moving distance measurement means and the direction sensor information, but is cumulative because it is a relative positioning method. If the error becomes large, there is a drawback that it is difficult to perform highly accurate positioning.

On the other hand, in the method using GPS positioning information, since absolute position information on the earth can be obtained, highly accurate positioning is possible, but it is necessary to receive radio waves from at least three GPS satellites. Therefore, the positioning itself is impossible in the urban areas where buildings are prone, or in places where radio waves from GPS satellites such as in tunnels and under highway viaducts cannot be received. Therefore, conventionally, in the case of an installation type navigation device mounted on a vehicle or the like, except for a portable navigation device that performs positioning only with GPS positioning means from a request for miniaturization, etc., self-contained navigation positioning means and GPS positioning means A navigation device is used that performs a certain degree of accurate positioning even when radio waves from an artificial satellite do not arrive at a GPS receiver while complementing each other. Further, in order to further improve the positioning accuracy, means for correcting measurement errors (map matching) by superimposing a plurality of calculated time-series position information with road data of map information stored in a DVD or ROM. Processing) is used.
A navigation device having such a function generally includes a GPS receiver, a GPS antenna connected thereto, a CPU for performing various controls, a self-contained navigation device including a gyro sensor and a vehicle speed sensor, and instructions for various settings. And a display unit for displaying the vehicle position and the like on a map based on the positioning result. In many cases, the map data and the like are stored in a DVD or ROM.
In addition, a normal navigation device displays a map in the vicinity of the current position, obtains accurate position information based on current position information and self-contained navigation information calculated by a GPS receiver, and displays a movement locus on the map. I have to. Further, the direction in which the host vehicle is traveling or the direction of a preset target point is also displayed, and the traveling direction is disclosed in Patent Document 1 as well as moving forward. Thus, when reverse (backing), the direction is displayed, and the device which makes it a little convenient for users, such as a driver and a passenger, is made.
JP 2005-30775 A

By the way, as described above, in the navigation device, it is difficult to accurately detect the position when the necessary number of radio waves from the artificial satellites do not arrive at the GPS receiver, and during that time, the distance traveled from the autonomous navigation means as described above. The position detection is performed by obtaining the information and the moving direction information, but if the state continues for a long time, the error of the self-contained navigation is accumulated, and the position detection accuracy is remarkably lowered.
However, in the conventional navigation apparatus, since measures such as clearly informing the user of the accumulation degree of such errors are not considered, there are many cases that the current position displayed is assumed to be correct. . If the navigation device is mounted on a vehicle used for leisure or commuting, there are many cases where some errors are not a problem. However, if you want to use relatively accurate current location information, you can rely on the displayed current location. It is extremely useful to know how much sex is. For example, there are many cases where detailed location information is required in a vehicle for transportation business or a delivery service for luggage.
The present invention has been made in order to solve such a problem in the conventional navigation device, and provides a navigation device that makes it possible to grasp the reliability of the information on the current position being displayed. It is an object.

In order to solve such a problem, the present invention provides a navigation apparatus according to claim 1, wherein the GPS reception means includes at least a display means for indicating a traveling direction or a destination direction. Non-positioning detection means for detecting a non-positioning state in which correct position detection processing cannot be performed by means, timer means for measuring the elapsed time of the non-positioning state, and when the elapsed time of the non-positioning state has passed a preset time And non-positioning display means for displaying that the display means is in a non-positioning state.
According to a second aspect of the present invention, in the navigation device according to the first aspect, the display means includes a first display mode indicating that the GPS receiving means is capable of executing a correct position detection process, and the non-positioning. A second display mode after the detection means detects the non-positioning state until the timer means counts a predetermined time, and the non-positioning detection means detects the non-positioning state, and the timer Means is provided for displaying at least three display modes of a third display mode indicating that the unit is after counting a predetermined time.

According to a third aspect of the present invention, the navigation apparatus according to the first or second aspect further comprises a self-contained navigation means including a gyro and a vehicle speed sensor.
According to a fourth aspect of the present invention, in the navigation device according to any one of the first to third aspects, the non-positioning detection means detects a non-positioning state in the second display mode and the third display mode. A means for displaying later elapsed time information is provided.
According to a fifth aspect of the present invention, the navigation device according to any one of the first to fourth aspects further comprises a map information supply means for displaying the current position on the map and the first display mode through the first display mode. It is configured to display any one of the third display modes.

  As described above, according to the present invention, the driver (user) can easily determine whether the destination direction and the traveling direction display are correct.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. . In addition, the same parts and the same matters as those already described are denoted by the same reference numerals and numbers, and redundant description is omitted.
FIG. 1 is a schematic configuration diagram showing an example of a navigation apparatus according to the present invention. The navigation apparatus 1 shown in this example includes a CPU 2 that controls the entire apparatus or a part of the apparatus, a RAM 3 that writes and reads necessary data, a ROM 4 that records programs, various setting data, and the like, A map memory 5 in which map information including road map information and various facility information is recorded, a display control circuit 6, and a display device 7 for receiving various controls based on the map information and the present invention described later under the control thereof. A parallel interface 8 that performs interface processing with the display device 7, a serial interface 9 that performs interface processing with an external device, and a timer circuit (TIMER) 10 that counts elapsed time. Connected by line 11.
Further, a GPS receiver 12 that transmits and receives data via the serial interface 9 and a self-contained navigation device 15 that includes a gyro 13 and a vehicle speed sensor 14 for obtaining movement direction information of the own vehicle are provided. This configuration is merely an example, and the present invention is not limited to this example, and the type of interface and the configuration of the self-contained navigation device are not limited to this example. In addition, the normal navigation operations and functions of the navigation apparatus configured as described above are already well known, and thus description thereof is omitted.

FIG. 2 shows an example of a display image of the display device 7 used in the present invention. (A) is a first display mode, (b) is a second display mode, and (c) is a third display mode. is there. Hereinafter, each display mode will be described in detail.
First, the first display mode shown in FIG. 2A is a display that is performed when the GPS receiver 12 receives radio waves of sufficient intensity from the required number of artificial satellites and accurate position information is obtained. is there. In this figure, a portion 20 of the number “1.5k” is a distance to a target point set in advance by the user, an arrow 21 indicates the direction of the destination or the traveling direction of the host vehicle, and an icon 22 simulating an artificial satellite. Indicates that accurate position information is obtained by receiving a required signal from a GPS artificial satellite. The mark (icon) 23 including the antenna mark and the vertical bar indicates the strength of the electric wave incoming field to the GPS receiver, the strength of radio waves such as radio broadcasts and radio waves for road information broadcasts, or new reception. Although the function is necessary, it may indicate the incoming radio wave intensity of the mobile phone system.
In addition, the second display mode shown in FIG. 2B is a state in which the GPS receiver 12 does not receive radio waves from the required number of artificial satellites and accurate position information cannot be obtained. It is a display that is performed before elapses The image shown in this figure is different from that shown in FIG. 2A in that the satellite icon 22 disappears. This makes it impossible to detect the position by the GPS receiver (non-positioning state). It is a notification that there is. This display indicates that if the position cannot be detected by the GPS receiver 12 and is within a certain time (for example, several minutes), the accuracy of the current position is maintained within a certain error. The value for a certain time is set according to the presence or absence of navigation means, the position detection accuracy, and the like.

The third display mode shown in FIG. 2 (c) is a display that is performed after a predetermined time has elapsed since the GPS receiver 12 no longer receives radio waves from the required number of artificial satellites. The image shown in this figure is characterized in that the satellite icon 22 disappears and the arrow mark 21 indicating the destination direction or traveling direction is displayed as a broken line. It is informed that the position detection by the machine is impossible and that the state has continued for a certain time or more. Thereby, since the driver (user) can easily determine whether the destination direction and the traveling direction display are correct, it is not necessary to watch the display screen, which is preferable for safe driving.
In the present invention, the display is changed according to the elapsed time after the position detection by the GPS receiver 12 becomes impossible (non-positioning state) as described above. It is possible to identify whether the accuracy of the position information displayed at that time is reliable, or whether the accuracy is not guaranteed and is information that should be kept as reference information.

FIG. 3 is a flowchart showing an example of control of the navigation device 1 configured as described above. In this flowchart, the first display mode described above is expressed as “GPS positioning state”, the second display mode is expressed as “GPS non-positioning state 1”, and the third display mode is expressed as “GPS non-positioning state 2”. ing. First, in this example, when the navigation device 1 is turned on, a position information update trigger signal is supplied to the required part. However, immediately after the navigation device 1 is turned on, the GPS receiver 12 does not detect the position. Accurate position detection is impossible, and “GPS non-positioning state 2 (third display mode)” shown in FIG. 2C is displayed. When the position information and target point information immediately before the power is turned off are stored in the RAM 3 or the like when the power is turned on, even if the position information by the GPS receiver 12 is not obtained, the distance and direction to the target point ( (Not traveling direction) can be displayed, but if the distance or direction to the target cannot be detected for some reason, the distance number 20 and the arrow mark 21 are not displayed (S1).
After a while, the position detection by the GPS receiver is executed (S2, Yes). When accurate position information is acquired, the “GPS positioning state (first display mode)” is displayed (S3). . Then, while monitoring whether or not position detection by the GPS receiver 12 is impossible (non-positioning state) in this state (S4), normal navigation processing is performed (No in S3 and S4). When it is determined that the position detection by the position 12 is impossible (non-positioning state) (S4, Yes), the timer circuit 10 for counting a predetermined time (T) set in advance is started (S5) and displayed. “GPS non-positioning state 1 (second display mode)” is displayed on the device 7 (S6). In this state, it is determined whether or not the timer circuit 10 has elapsed for a certain period of time. If it is determined that the timer circuit 10 has elapsed (S7, Yes), the process proceeds to S1, and "GPS non-positioning state 2 (third display mode) ) ”Is displayed. Thereafter, the navigation process is performed while repeating the same process. In the above processes S6 to S7, it is determined whether or not the position detection process by the GPS receiver 12 has been resumed before a predetermined time has elapsed. If the position detection process has been resumed, the GPS process state is changed so as to shift to S1. It is preferable to monitor in parallel.

Various means (non-positioning state detecting means) for detecting that the GPS receiver 12 is in a state in which position detection processing cannot be performed are conceivable. For example, since a GPS receiver having a function of detecting the number of artificial satellites being received is common, use of the signal and whether the GPS receiver is normal in position calculation processing or not. In the case of a device having a determination function, it is possible to use the information, and to display the number of artificial satellites at the same time is useful for determining the accuracy of the current position information.
There are various display methods. For example, in addition to displaying an arrow with a broken line, blinking display and simultaneously displaying red to prompt a warning also have an effect of calling the user's attention.
In the above-described example, the distance to the target, the direction, and the presence / absence of position detection by the GPS receiver are shown. However, such a display is displayed on a required part of the displayed map screen, A method of displaying icons and displays side by side at the bottom of the map display screen can be considered. In addition to displaying the traveling direction arrow with the north direction up, it is easier for the user to change the direction arrow according to the direction of the map to be displayed.

  The present invention is not limited to the above example and can be variously modified. For example, as shown in FIGS. 4 and 5, the elapsed time in a state where position detection by the GPS receiver is impossible can be displayed. That is, the example of the display shown in FIG. 4 is a diagram showing another example of the display until a certain time elapses after the position detection by the GPS receiver becomes impossible. The arrow icon 21 indicating the moving direction of the satellite is displayed, and the satellite icon 22 is off. In this example, an image 24 indicating the elapsed time is displayed instead of the artificial satellite icon. This display shows the elapsed time (minute display) in the double circle, and the double circle part displays the number of seconds. Every time the number of seconds in the double circle reaches 60 seconds, the fraction is displayed. Increment and display. Further, based on the same concept, as shown in FIG. 5, when the position undetectable time by GPS reception exceeds a certain time (T), the direction arrow 21 is displayed with a broken line and the elapsed time is displayed. ing. The elapsed time in FIG. 5 may be a time after a certain time has elapsed, or may be a time including the second display time. Furthermore, changing the color of these displays is also effective for informing the user to make it easier to understand. Further, the elapsed time display method shown in FIGS. 4 and 5 is not limited to this example, and may be based on gradation or color change of the scale display of the horizontal bar and the vertical bar arranged in the peripheral part of the screen.

Further, as an apparatus with further improved functions, it is convenient for the user to evaluate the accuracy of the currently displayed position information by a predetermined algorithm and display the result as a numerical value, an icon or the like. For example, in the case where the self-contained navigation is used in combination, the GPS receiver can detect the position with a certain degree of accuracy even when the GPS receiver cannot receive the radio wave from the artificial satellite, so the map matching process is performed based on the obtained position information, It is also possible to evaluate the position accuracy according to the degree of matching. Such a function can be added as an item that can be selected by the user on the menu screen.
It is also possible to program the processing for realizing the navigation device according to the present invention in accordance with an OS that can be controlled by a computer. It is possible to control by the same processing method by installing the program in a navigation apparatus having a computer function with the same OS. If such a program is recorded on a recording medium, the program can be operated anywhere by carrying the recording medium. As a recording medium for storing the program, a semiconductor medium (for example, ROM, nonvolatile memory card, etc.), an optical medium (for example, DVD, MO, MD, CD, etc.), a magnetic medium (for example, magnetic tape, flexible disk, etc.) ) Or the like.

The block diagram which shows one Example of the navigation apparatus of this invention. It is a figure which shows the example of a display of the navigation apparatus of this invention, (a) is a 1st display mode, (b) is a 2nd display mode, (c) is a figure which shows a 3rd display mode. The flowchart which shows the process example of the navigation apparatus of this invention. The figure which shows the other example of a display of the navigation apparatus of this invention. The figure which shows the other example of a display of the navigation apparatus of this invention.

Explanation of symbols

  1 navigation device, 2 CPU, 3 RAM, 4 ROM, 5 map memory, 6 display control circuit, 7 display device, 8 parallel interface, 9 serial interface, 10 timer, 11 bus line, 12 GPS receiver, 13 gyro, 14 Vehicle speed sensor, 15 Self-contained navigation device

Claims (5)

  In a navigation apparatus comprising a GPS receiving means and a display means that indicates at least the traveling direction or the direction of the destination, a non-positioning detecting means for detecting a non-positioning state in which correct position detection processing by the GPS receiving means cannot be performed, Timer means for measuring the elapsed time of the positioning state, and non-positioning display means for indicating that the display means is in the non-positioning state when the elapsed time of the non-positioning state has passed a preset time. A navigation device characterized by the above.   2. The navigation device according to claim 1, wherein the display unit is configured to display a first display mode indicating that the GPS receiving unit is capable of executing a correct position detection process, and the non-positioning detection unit is in a non-positioning state. A second display mode indicating that the timer means counts a predetermined time after detection; a state in which the non-positioning detection means detects a non-positioning state; and the timer means A navigation apparatus comprising: means for displaying at least three display modes of a third display mode indicating that the predetermined time is after counting.   3. The navigation apparatus according to claim 1, further comprising self-contained navigation means including a gyro and a vehicle speed sensor.   The navigation device according to any one of claims 1 to 3, wherein the second display mode and the third display mode display elapsed time information after the non-positioning detection means detects a non-positioning state. A navigation device comprising means for performing   5. The navigation device according to claim 1, further comprising a map information supply unit that displays a current position on a map and any one of the first display mode to the third display mode. A navigation device configured to display

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