JP2009204430A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device capable of preventing deterioration in the positioning accuracy, even when vehicle speed sensor information having a probability of not acquiring a normal signal caused by a connection error or the like is not supplied, or in the case of a car model incapable of originally acquiring a vehicle speed pulse signal, and capable of preventing increase of current consumption caused by wasteful processings. <P>SOLUTION: In this navigation device equipped with a vehicle speed sensor input setting means for setting whether the vehicle speed sensor information is to be used at position information operation processing, when such an effect is set where that the vehicle speed sensor information is not used, position information is operated, based on information from a GPS receiving means and information from a gyro sensor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a navigation device mounted on a vehicle or the like, and in particular, improved processing when vehicle speed information cannot be input when specifying a position using GPS positioning information and vehicle speed information. The present invention relates to a navigation device.

In the past, navigation devices mounted on mobile objects such as automobiles used position detection means by self-contained navigation equipped with gyros (compasses), acceleration sensors, etc., but in the 90s, GPS positioning information was used. Navigation devices have become commercially available. 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 have been provided.
In general, the self-contained navigation positioning means can detect the position of the host vehicle with a relatively simple device configuration using a moving distance measuring means or a direction sensor using a gyroscope or the like. For this reason, when the accumulated error becomes large, there is a drawback that high-precision positioning is difficult.
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, positioning itself is impossible in urban areas where buildings are prone, or in places where GPS satellites cannot be received, such as in tunnels or under highway viaducts. 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 due to a request for miniaturization, etc., self-contained navigation positioning means and GPS positioning means A navigation device is used that always performs accurate positioning while supplementing each other by using them together. 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.

FIG. 4 is a schematic block diagram showing a configuration example of a conventional navigation apparatus having such a function. The navigation device 20 shown in this example includes a GPS receiver 21, a GPS antenna 22 connected thereto, a CPU 23 for performing various controls, a gyro sensor 24, a vehicle speed sensor 25, an input unit 26 for instructing various settings, A display unit 27 for displaying the vehicle position and the like on the map based on the positioning result is provided. It should be noted that the illustration of the HDD and ROM in which the map data is recorded and the reproducing device thereof is omitted.
By the way, in the self-contained navigation positioning means, the moving speed information of the own vehicle is necessary as one of the moving distance measuring means, and therefore, a vehicle speed sensor 25 is provided as shown in FIG. Although there are some differences depending on the vehicle such as an automobile, for example, a predetermined pulse signal is generated every time a predetermined distance is moved, and a speed (meter) display or a travel distance display is generally performed based on the pulse signal. The vehicle speed sensor 25 detects the relative movement distance of the own vehicle by receiving the supply of the vehicle speed pulse signal 28 generated corresponding to the movement speed of the vehicle, and is used for position measurement. .
Usually, in the installation type navigation apparatus as shown in FIG. 4, the vehicle position measurement processing is executed on the assumption that all the self-contained navigation positioning information including the GPS positioning information and the vehicle speed sensor information is normally supplied. As described above, the CPU 23 is provided with a program based on the processing algorithm. Therefore, when a navigation device is mounted on a passenger car or the like, installation work or the like is performed so that such information is normally supplied. At this time, since the gyro sensor 24, the GPS receiver 21, and the like are built in the navigation device 20, no special care is required when the navigation device 20 is attached to a vehicle or the like, but the gyro sensor 24 and the GPS receiver 21 are supplied to the vehicle speed sensor 25 described above. It is often necessary to pay attention to the input of the power vehicle speed pulse signal 28. That is, when the generation mechanism of the vehicle speed pulse signal is different for each vehicle, or when the color of the line used as the vehicle speed pulse signal line is different, a considerably troublesome work is required, and incorrect wiring work is performed. The possibility has been pointed out. And if a navigation apparatus is operated in the state where a correct signal is not supplied to a vehicle speed sensor, there is a possibility that an accurate navigation function may not be exhibited.
Conventionally, what was described in patent document 1 is known as a countermeasure with respect to such a malfunction. As shown in FIG. 3 (flowchart) of Patent Document 1, this includes the supply of vehicle speed pulses including the process of determining whether or not the correct vehicle speed pulse is supplied to the vehicle speed sensor during the navigation process. The vehicle position update process is performed by self-contained navigation, but if the correct vehicle speed pulse signal is not supplied, the vehicle position update process is performed based on the position information difference based on the GPS positioning information. It is what I do.
JP 2007-24701 A

However, in the conventional method described above, since it is frequently determined whether or not the vehicle speed pulse signal is supplied during the position detection process, the processing load on the CPU and the like increases, and the current consumption increases accordingly. Furthermore, depending on how the processing algorithm is constructed, efficient processing may not always be performed.
For example, as shown in FIG. 5 (a), the vehicle position detection process is based on vehicle speed sensor information (information based on a vehicle speed pulse signal), GPS positioning information, gyro sensor information, and map matching processing. As shown in FIG. 5A, vehicle weight sensor information (30%), GPS positioning information (30%), gyro sensor information (30%), map matching (10%) Consider the case. When the information of the three parties except for the map matching process is obtained normally, if the weighting is optimally set to 30%, the vehicle speed sensor information cannot be obtained. As shown in the figure, it is conceivable to simply assign 15% of the weighting for the vehicle speed sensor information to the remaining gyro sensor information and GPS positioning information, respectively. However, the gyro sensor information can be measured by accurate self-contained navigation (positioning means) by combining with the vehicle speed sensor information. Therefore, if the gyro sensor information is used alone without the vehicle speed sensor information, the positioning accuracy Is likely to decrease. Therefore, for example, as shown in FIG. 5C, it is preferable to assign all weights of the vehicle speed sensor information to the GPS positioning information. In the first place, it is often seen in foreign cars and diesel cars, but there are also some car models that cannot originally acquire vehicle speed pulse signals.

In view of such a situation, as described in Patent Document 1, the processing algorithm is changed such as frequently determining the presence or absence of vehicle speed sensor information during the processing and changing the weighting according to the result. In this case, the processing becomes complicated and there is a possibility that high-speed processing may be hindered.
The present invention has been made to solve the problems associated with such conventional navigation devices, and in a navigation device that uses both self-contained navigation positioning means and GPS positioning information, a normal signal is generated due to a connection error or the like. Even if vehicle speed sensor information that may not be obtained is not supplied, or even if the vehicle model cannot originally acquire a vehicle speed pulse signal, the positioning accuracy is prevented from decreasing, and the increase in current consumption due to unnecessary processing is prevented. The object is to provide a navigation device.

In order to solve such a problem, the present invention provides a navigation device according to claim 1, which includes a GPS receiving means, a gyro sensor, a vehicle speed sensor, a display means, a CPU and a required memory, In a navigation apparatus comprising main control means for calculating position information based on required information from information on means, information on gyro sensor, information on vehicle speed sensor, and input means for making various settings, the main control means includes Is a vehicle speed sensor input setting means for setting whether or not to use the information of the vehicle speed sensor in the position information calculation process, and a setting not to use the information of the vehicle speed sensor by the vehicle speed sensor input setting means The position information is calculated based on only the information of the GPS receiving means or the information of the GPS receiving means and the information of the gyro sensor. Characterized by comprising a stage.
According to a second aspect of the present invention, in the navigation device according to the first aspect, at least the vehicle speed sensor input determining means for determining whether or not the vehicle speed sensor input is normal, and the vehicle speed sensor input is not normal. In this case, there is provided means for displaying vehicle speed sensor input error information on the display means.

According to a third aspect of the present invention, in the navigation device according to the first or second aspect, when calculating the position information, the GPS receiving means, the gyro sensor, and the vehicle speed sensor are each weighted with predetermined weights. And a means for assigning a weighting amount for the information of the vehicle speed sensor to the information of the GPS receiving means when the vehicle speed sensor input setting means is configured not to use the information of the vehicle speed sensor.
According to a fourth aspect of the present invention, in the navigation apparatus according to any one of the first to third aspects, the main control unit includes a map matching processing unit.

  Since the present invention is configured as described above, if vehicle speed sensor input cannot be obtained from a vehicle equipped with a navigation device, the vehicle speed sensor input setting means sets in advance that the vehicle speed sensor is not used, thereby In the calculation process, it is possible to calculate the position information based on the information of the GPS receiving means alone or the GPS receiving means and the gyro sensor without including the process of determining the presence or absence of the vehicle speed sensor. Therefore, the processing load on the CPU and the like is reduced, and it is not necessary to operate the vehicle speed pulse input circuit, so that the current consumption can be reduced and the processing speed can be increased. In addition, there is an effect of preventing deterioration in position information accuracy caused by performing position information calculation processing using vehicle speed sensor information in a state where a normal vehicle speed pulse signal is not supplied.

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 device 10 shown in this example includes a GPS antenna 1 that receives radio waves from an artificial satellite in the sky, a GPS receiver 2 connected thereto, a CPU that performs various controls, a memory that stores a program, and the like. 3, a gyro sensor 4, a vehicle speed sensor 5, an input unit 6 for instructing various settings, and a display unit 7 for displaying the position of the vehicle on a map based on the positioning result. It should be noted that illustration of the DVD and ROM on which the map data is recorded and the reproducing apparatus thereof is omitted.

The navigation device shown in this example is different from the conventional one shown in FIG. 4 in that whether or not the vehicle speed sensor 5 (and) or the main control unit 3 uses the information of the vehicle speed sensor in the position information calculation process. The vehicle speed sensor input setting means 8 is provided. When the vehicle speed sensor input setting means 8 sets the vehicle speed sensor information not to be used, the main control device 3 uses the information supplied from the GPS receiver 2 without using the vehicle speed sensor 5 information. Only, or based on the information of the GPS receiver 2 and the gyro sensor 4, the position information is calculated. Therefore, as described in the conventional patent document 1, the position information is obtained without frequently determining whether the correct vehicle speed pulse signal is supplied to the vehicle speed sensor 5 during the calculation process for obtaining the position information. Arithmetic processing can be executed.
As the vehicle speed sensor input setting means 8, as shown in FIG. 1, a changeover switch SW is used to set a predetermined terminal (not shown) to ground potential when the vehicle speed sensor information is not used. When the information of the vehicle speed sensor is used, the predetermined terminal may be switched to a high potential (ON). Such a signal may be supplied to the vehicle speed sensor 5, simultaneously to a required terminal of the main control unit 3, or may be supplied only to the main control unit 3. Alternatively, the same setting may be performed using a numeric keypad of the input unit 6 or other control buttons. Furthermore, it is also possible to adopt a liquid crystal display having a touch sensor function as the display unit 7 so as to perform a desired setting by displaying a required menu and touching a necessary item. .

FIG. 2 is a flowchart showing an example of processing of the navigation device of the present invention, and is a flow for setting whether to use vehicle speed sensor information performed when the navigation device is mounted on a vehicle or the like.
In the process shown in this example, when the own vehicle position information (own vehicle position specifying) process starts, first, determination of the vehicle speed sensor setting is performed (S1). As described above, when the navigation device is mounted on a vehicle or the like, the vehicle speed sensor is set according to whether or not the correct vehicle speed pulse signal can be supplied to the vehicle speed sensor. Keep it. In process S1, this setting is confirmed. When a vehicle speed sensor is used (S1, Y), information on the vehicle speed sensor is analyzed (S2), and it is determined whether the information is correct (S3). . In this determination, when it is determined that the vehicle speed sensor information is correct (S3, Y), it is assumed that there is vehicle speed sensor information, and further, the vehicle position calculation process is performed including gyro sensor information and GPS positioning information ( S4). On the other hand, if it is determined that the information is not correct in the determination of the correctness of the vehicle speed information in S3 (S3, N), a caution display (alarm display) indicating that the vehicle speed sensor information is incorrect is displayed on the display device to notify the user. (S6). Corresponding to this display, if the user performs any operation, processing is performed according to the instruction, but if the user does not perform any operation, or if the user's instruction performs the processing as it is If the vehicle speed information is, the process proceeds to S4, and the vehicle position calculation process is performed using the vehicle speed sensor information supplied at that time (S4). Furthermore, in the process of S1, if the vehicle speed sensor setting is OFF, that is, the setting that the vehicle speed sensor information is not used is made (S1, N), the gyro sensor information and the vehicle speed sensor information are not used. The vehicle position is calculated based on the GPS positioning information (S7).
According to such a process, a calculation process for obtaining position information without frequently determining whether or not a correct vehicle speed pulse signal is supplied to the vehicle speed sensor 5 during a calculation process for obtaining position information as in the prior art. Therefore, effects such as speeding up of processing and reduction of current consumption can be obtained.

FIG. 3 is a flowchart showing a modified embodiment of the present invention in which a part of the processing shown in FIG. 2 is changed. In this example, S1 to S7 are the same as those in FIG. The difference is that S8 is inserted in between. That is, the vehicle speed sensor setting is determined (S1). If the changeover switch SW in FIG. 1 is ON (S1, Y), the vehicle speed sensor information is analyzed (S2), and whether the information is correct or not. As a result of determining (S3), if it is determined that the vehicle speed information is not correct (S3, N), a caution display (alarm display) indicating that the vehicle speed sensor information is not correct is displayed on the display device, and the user is notified (S6). ). Corresponding to this display, it is determined whether or not the user performs any operation within a predetermined time (S8). If no operation is performed (the SW is already turned ON), the operation of S4 is performed. The process proceeds to the process (S8, N) and the vehicle position calculation process is performed using the vehicle speed sensor information supplied at that time (S4). If the SW is turned OFF in S8, the process of S7 is performed. The vehicle position calculation is performed based on the gyro sensor information and the GPS positioning information without using the vehicle speed sensor information (S7). When the SW is turned off in the operation of S8, the same processing as in the case where it is determined in S1 that the vehicle speed sensor is absent (N) can always be performed.
The flowcharts shown in FIGS. 2 and 3 have been described as processing for setting whether to use vehicle speed sensor information performed when the navigation device is mounted on a vehicle or the like. It may be included in the processing during operation. At that time, if the determination of the vehicle speed sensor setting in S1 is only to determine the ON / OFF state of the SW, it is not necessary to determine whether the vehicle speed sensor information is correct or not. It does not increase and the current consumption does not increase. When the flow of FIGS. 2 and 3 is included in the process at the time of actual operation, it is only necessary to return to S1 again and repeat the process after the end of specifying the vehicle position in S5.
The gyro sensor, the vehicle speed sensor, the GPS receiver, the map matching process, and the like used for realizing the navigation device according to the present invention are well-known in many documents including Patent Document 1, and so on. The detailed explanation is omitted.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and various modifications are possible. For example, as described with reference to FIG. 5, the weighting ratios of the vehicle speed sensor information, the GPS positioning information, and the gyro sensor information are appropriately changed, or the GPS positioning information and the gyro sensor information when the vehicle speed sensor information is not used. As shown in FIG. 5C, assigning all the weights of the vehicle speed sensor information to the GPS positioning information is also effective in improving the positioning accuracy. Needless to say, the map matching process may be used together as in the prior art. Furthermore, if the vehicle position information is corrected using the vehicle speed sensor information, if the error is large (the correction amount is large), the vehicle speed sensor information is excluded and the position information is calculated again, and the correction error is reduced. If the error is small, a caution display indicating that the vehicle speed sensor information is not normal may be displayed. If the user turns off the vehicle speed sensor SW in accordance with this caution display, processing in a mode that does not use vehicle speed sensor information is performed thereafter.
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. The flowchart which shows the process example of the navigation apparatus of this invention. The flowchart which shows the other example of a process of the navigation apparatus of this invention. The block diagram which shows the conventional navigation apparatus outline | summary. It is a figure which shows the example of the weighting of the sensor information at the time of position information calculation by a navigation apparatus, (a) is a case where vehicle speed sensor information is used, (b) And (c) is a figure which shows the case where vehicle speed sensor information is not used.

Explanation of symbols

  1 GPS antenna, 2 GPS receiver, 3 main control unit, 4 gyro sensor, 5 vehicle speed sensor, 6 input unit, 7 display unit, 8 vehicle speed sensor input setting means, 9 vehicle speed pulse signal, 10 navigation device, SW vehicle speed sensor Changeover switch

Claims (4)

  A GPS receiving means, a gyro sensor, a vehicle speed sensor, a display means, a CPU and a memory are included, and position information is obtained based on required information from among the information of the GPS receiving means, the information of the gyro sensor, and the information of the vehicle speed sensor. In a navigation device comprising a main control means for calculating and an input means for performing various settings, a vehicle speed sensor for setting whether or not information of the vehicle speed sensor is used for position information calculation processing in the main control means When setting that the information of the vehicle speed sensor is not used by the input setting unit and the vehicle speed sensor input setting unit is performed, only the information of the GPS receiving unit, or the information of the GPS receiving unit and the information of the gyro sensor A navigation apparatus comprising means for calculating position information based on the information.   2. The navigation device according to claim 1, wherein at least vehicle speed sensor input determination means for determining whether or not the vehicle speed sensor input is normal and vehicle speed sensor input error information when the vehicle speed sensor input is determined to be normal. A navigation apparatus comprising means for displaying on the display means.     The navigation device according to claim 1 or 2, further comprising means for performing predetermined weighting on information of the GPS receiving means, the gyro sensor, and the vehicle speed sensor when calculating position information, and the vehicle speed sensor input setting means. A navigation device comprising means for assigning a weighting amount for information on the vehicle speed sensor to information on the GPS receiving means when setting is made to not use the information on the vehicle speed sensor.   4. The navigation apparatus according to claim 1, wherein the main control unit includes a map matching processing unit.

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