JP2011153978A - Current-position display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cancel and smoothly display errors, when a current position based on a GPS signal is separated from a display position, when the GPS signal is received again. <P>SOLUTION: A current-position display device calculates the current position, based on a GPS-receiving means and displays a current position mark. The current-position display device includes a position comparing means that when the GPS signal cannot be received by the GPS receiving means and then the GPS signal is received again, calculates the current position at which the GPS signal is received again by the current-position calculating means, and determines whether the calculated current position is separated from the position of the current position mark by a predetermined distance or larger. When the separation by the predetermined distance or longer is determined by the position comparing means, a display position determining means moves the position of the current position mark so that the position gradually approaches the current position calculated by the current-position calculating means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a current position display device, and more specifically, a current position for performing display that eliminates a shift in the display position of the current position that occurs when moving from a section that cannot receive GPS signals, such as a tunnel, to a section that can receive GPS signals. The present invention relates to a display device.

  A car navigation device used for guidance of an automobile or the like is to identify a current position of a vehicle by receiving a signal from a GPS satellite and display the specified current position on a map to guide a user. is there. Also, the starting point and the destination are input as route search conditions, the route search is performed so as to satisfy the route search condition, the optimum route between them is specified, the optimum route is displayed on the map, and along this route Route guidance.

  In many car navigation systems, in addition to positioning the current position using GPS signals, the current position can be detected more accurately by cooperating with a vehicle speed sensor or an autonomous navigation means such as a gyroscope installed in an automobile or the like. Has been done. By using the autonomous navigation means, the distance and direction traveled by the vehicle can be detected in detail. As a result, the accuracy of specifying the current position can be improved, and the current position can be specified even in places where GPS signals such as tunnels and valleys of buildings cannot be received.

  Patent Document 1 (Japanese Patent Laid-Open No. 06-317650) described below determines whether or not the current position is in a tunnel when a GPS signal cannot be received. An apparatus is disclosed.

  Patent Document 2 (Japanese Patent Laid-Open No. 05-010774) includes a GPS receiver, a geomagnetic sensor, and an acceleration sensor, and uses information from the acceleration sensor and the geomagnetic sensor when information from a GPS satellite cannot be received. Thus, a navigation device for specifying the current position is disclosed. Thereby, even when a GPS signal cannot be received in a tunnel or a valley of a building, the current position can be specified and displayed on the display unit of the navigation device without interruption.

Japanese Patent Laid-Open No. 06-317650 Japanese Patent Laid-Open No. 05-010774

  However, when a vehicle such as an automobile equipped with a navigation device travels on a route such as a tunnel where GPS signals cannot be received, if the navigation device is as described in Patent Document 1, the current position display can receive GPS signals. When the vehicle is running, the tunnel display will be highlighted and then restarted at the tunnel exit where GPS signals are received again. It cannot be displayed continuously.

  Further, in the case of the navigation device as described in Patent Document 2, the current position in the tunnel can be specified based on the output of the geomagnetic sensor or the acceleration sensor and displayed on the map while traveling through the tunnel. The actual position of the vehicle may be displaced from the displayed position due to an error included in the output of the sensor or acceleration sensor. In addition, when there is a sudden acceleration / deceleration in the tunnel, the difference between the actual position of the vehicle and the position calculated by the navigation device becomes larger. This difference can be improved by the vehicle exiting the tunnel, receiving the GPS signal again, and correcting the current position display to the current position based on the GPS signal. It will appear as if it has been skipped.

  That is, when the position calculated by the navigation device based on the output of the acceleration sensor or the like is behind the actual vehicle position, the current position display is corrected to the current position based on the GPS signal when the vehicle leaves the tunnel. Because the current position display fluctuates by the delayed distance, the current position of the vehicle suddenly appears (skips).

  Therefore, when the GPS signal can be received again after passing through a section where the GPS signal cannot be received, the present invention, when the current position specified from the GPS signal and the current position display are separated, It is an object of the present invention to provide a current position display device that displays the error smoothly.

  In order to solve the above problems, the invention according to claim 1 of the present application includes a display means, a GPS receiving means, a current position calculating means for calculating a current position based on a GPS signal received by the GPS receiving means, Display position determination means for determining the position of the current position mark displayed on the display means based on the current position calculated by the current position calculation means before the GPS signal cannot be received. In the apparatus, the current position display device is configured to receive the GPS signal again by the current position calculating unit when the GPS signal is received again after the GPS receiving unit cannot receive the GPS signal. A position ratio for determining whether or not the calculated current position and the position of the current position mark are more than a predetermined distance And the display position determining means gradually approaches the position of the current position mark to the current position calculated by the current position calculating means when it is determined that the position comparing means is separated by a predetermined distance or more. It is made to move as follows.

  The invention according to claim 2 of the present application is the invention according to claim 1, wherein the current position display device includes autonomous navigation means, and the current position calculation means cannot receive the GPS signal by the GPS receiving means. In this case, the current position is calculated based on the current position calculated before the GPS signal cannot be received and the output of the autonomous navigation means, and the display position determining means is configured to calculate the current position based on the calculated current position. The position of the mark is determined.

  In the invention according to claim 3 of the present application, in the invention according to claim 1 or 2, when it is determined that the position comparison means is separated by a predetermined distance or more, the display position determination means is determined by the current position calculation means. Each time the current position is calculated, the position of the current position mark is moved stepwise to the calculated current position.

  In the invention according to claim 4 of the present application, in the invention according to claim 1 or 2, when the position comparison means determines that the distance is more than a predetermined distance, the display position determination means receives the GPS signal again. The present position mark is moved so as to approach the current position mark stepwise.

  The invention according to claim 5 of the present application is the invention according to claims 1 to 4, wherein the display position determining means determines the position of the current position mark in accordance with the scale of the map displayed on the display means. Whether to move the current position calculated step by step to the current position calculated by the current position calculating means is switched.

  The invention according to claim 6 of the present application is characterized in that, in the invention according to claims 1 to 5, the value of the predetermined distance is varied in accordance with the scale of the map displayed on the display means.

  According to the first aspect of the present invention, when it is determined that the current position calculated based on the GPS signal received again and the position of the current position mark are more than a predetermined distance apart, the current displayed on the display means Since the position is moved so as to gradually approach the current position calculated based on the GPS signal, it is prevented that the current position of the vehicle suddenly appears as if it has been skipped. Is possible.

  According to the invention of claim 2 of the present application, when the GPS signal cannot be received, the current position is calculated based on the current position calculated before the GPS signal cannot be received and the output of the autonomous navigation means. Since the current position is determined based on this, the current position can be calculated even when a GPS signal such as a tunnel cannot be received.

  According to the invention of claim 3 of the present application, when the current position when the GPS signal is received again and the position of the current position mark are separated by a predetermined distance or more, the calculation is performed each time the current position is calculated. The current position mark is moved closer to the current position in a stepwise manner, and every time the current position is calculated, the current position mark approaches the calculated current position. It is possible to prevent the display from appearing as if it has been skipped.

  According to the invention of claim 4 of the present application, when the current position when the GPS signal is received again and the position of the current position mark are separated by a predetermined distance or more, the current position when the GPS signal is received again. In order to move the current position mark so as to gradually approach the current position mark, the current position mark is gradually changed to the current position when the GPS signal is received again until the current position is calculated next time. Because the position of the current position mark is updated in a short update cycle in order to move closer, the current position of the vehicle suddenly jumps because it gradually approaches the current position when the GPS signal is received again. It is possible to prevent the display (like skipped) from being displayed.

  According to the invention of claim 5 of the present application, according to the scale of the map displayed on the display means, whether or not to move the position of the current position mark so as to gradually approach the calculated current position. Since switching is performed, when the effect of the present invention is difficult to obtain, such as when the map is in a wide area, the processing of the present invention is not performed and unnecessary processing is not performed.

  According to the invention of claim 6 of the present application, since the value of the predetermined distance is changed according to the scale of the map displayed on the display means, the effect of the present invention can be obtained when the map is a wide area. When difficult, less processing is performed, and when the effect of the present invention is remarkably obtained, such as when the map is detailed, the processing of the present invention can be performed reliably. .

It is an internal block diagram of the navigation apparatus 10 which concerns on the Example of this invention. It is a flowchart which shows the display operation of the present position in the tunnel exit vicinity in the navigation apparatus 10 concerning a present Example. It is a flowchart following FIG. It is a conceptual diagram of correction of the display position which the navigation apparatus 10 performs in the vicinity of a tunnel exit according to the flowchart of FIG.2 and FIG.3. It is a flowchart which shows the display operation of the present position when the present position display is ahead of the actual vehicle position in the vicinity of the tunnel exit in the navigation device 10 according to the present embodiment. It is a conceptual diagram of correction of the display position which the navigation apparatus 10 performs in the tunnel exit vicinity according to the flowchart of FIG.

  The best mode for carrying out the present invention will be described below in detail with reference to FIGS. However, the embodiment described below is described by exemplifying a navigation device for embodying the technical idea of the present invention, and is not intended to specify the present invention as this navigation device. The present invention can be equally applied to other current position display devices without departing from the technical idea shown in the claims.

  First, a navigation device 10 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an internal block diagram of the navigation apparatus 10 according to the embodiment of the present invention.

  The navigation apparatus 10 includes a control unit 100, a GPS reception unit 111, an autonomous navigation unit 112, a current position calculation unit 113, a position comparison unit 114, a display position determination unit 115, an input unit 116, a map storage unit 117, a route search unit 118, A display means 119 is provided.

  The control unit 100 includes a microprocessor including a CPU 101, a ROM 102, and a RAM 103, and controls the operation of each unit of the navigation device 10 by executing a program stored in the ROM 102 on the CPU 101.

  The GPS receiving means 111 includes an antenna that receives GPS signals including position information and time information of each GPS satellite from a plurality of GPS satellites orbiting the earth. The GPS signal includes two types of data, almanac data and ephemeris data. The almanac data includes orbit information of all GPS satellites and correction information of the satellite clock, and the ephemeris data includes detailed position information of each GPS satellite and time information when the GPS signal is emitted.

  The autonomous navigation means 112 is connected to an acceleration sensor, a gyro sensor, or the like installed in a vehicle on which the navigation device 10 is mounted, and converts a detection signal from the sensor into an appropriate output signal. Note that the navigation device 10 may include sensors such as an acceleration sensor and a gyro sensor.

  Based on the almanac data and the ephemeris data received by the GPS receiving unit 111, the current position calculating unit 113 calculates an estimated current position (estimated current position based on the GPS signal) of the vehicle including latitude information and longitude information.

  The current position calculation means 113 generally calculates an estimated current position based on the GPS signal at a predetermined time interval, for example, one second interval in this embodiment. The current position calculation unit 113 can calculate the angular velocity, acceleration, speed, and the like of the vehicle based on the estimated current position calculated this time and the estimated current position calculated last time. Accordingly, the current position calculation means 113 calculates values such as the current position, speed, angular velocity, and acceleration of the vehicle once per second.

  The current position calculation means 113 further calculates an estimated current position (estimated current position based on the autonomous navigation means 112) based on the output of the acceleration sensor converted and output from the autonomous navigation means 112 and the output of the gyro sensor. For example, in the autonomous navigation means 112 of the present embodiment, the angular velocity and acceleration are detected every 10 msec, and the average value of the angular velocity and acceleration (each 10 pieces of data) detected every 10 msec is calculated every 100 msec, Furthermore, the moving average is performed using 10 data of the average value of the angular velocity and acceleration calculated every 100 msec, and the processing for obtaining the angular velocity and acceleration of the vehicle is performed. In the moving average value calculation process every 100 msec, the latest 10 data obtained every 100 msec are used and the average value is deleted every 100 msec (the first data is deleted and the eleventh data is adopted). To calculate.

  Then, the current position calculation means 113 calculates the estimated current position based on the autonomous navigation means 112 by using the angular velocity and acceleration calculated by the autonomous navigation means 112 using the estimated current position based on the GPS signal as a reference.

  Here, in this embodiment, the estimated current position based on the GPS signal is 1 second intervals, and the angular velocity and acceleration calculated by the autonomous navigation means 112 are 100 msec intervals. By calculating the position of the vehicle (during 1 second) based on the autonomous navigation means 112, the update interval of the position of the vehicle is shortened, and the accuracy of specifying the position of the vehicle is improved.

  When the estimated current position based on the autonomous navigation means 112 is continuously calculated, the angular velocity and acceleration calculated by the autonomous navigation means 112 are used based on the estimated current position calculated based on the autonomous navigation means 112 calculated last time. It is preferable to calculate the estimated current position based on the autonomous navigation means 112 by

  As described above, the current position calculating unit 113 calculates the current position of the vehicle by the GPS receiving unit 111 and the autonomous navigation unit 112. In addition to this, the estimated current position calculated by receiving the GPS signal and the previously calculated estimated position are used. When the vehicle speed calculated from the current position is 20 km / h or less, the estimated current position by the GPS receiving unit 111 is used, and when the vehicle speed exceeds 20 km / h, the estimated current position by the autonomous navigation unit 112 is used. In addition, when the difference between the estimated current position by the GPS receiving unit 111 and the estimated current position by the autonomous navigation unit 112 is greater than or equal to a predetermined value, the estimated current position by the autonomous navigation unit 112 is estimated by the GPS receiving unit 111. You may comprise so that it may offset to a present position.

  In addition, when the vehicle is traveling in a place where GPS signals cannot be received and the estimated current position cannot be calculated based on GPS signals, such as underground passages and tunnels, or due to the influence of multipath, a large error may occur in the positioning results by the GPS receiving unit 111. When traveling in a building district or the like where such a situation occurs, the estimated current position based on the GPS receiving means 111 is not adopted, and the estimated current position based on the autonomous navigation means 112 is used. Conversely, when a large error occurs in the estimated current position by the autonomous navigation means 112 due to errors in the gyro sensor and the acceleration sensor, the estimated current position based on the GPS receiving means 111 is used.

  When the position comparison unit 114 can receive the GPS signal again after traveling in a section such as a tunnel where GPS signals cannot be received, the position comparison unit 114 and the current position display 420 up to that point (see FIG. 4). A reference position) (the display position of the current position specified by the display position determination means 115 to be described later based on the output of the autonomous navigation means 112) and determine how far they are separated It is. That is, when traveling in a section such as a tunnel where GPS signals cannot be received, the estimated current position based on the autonomous navigation means 112 is adopted as described above, and therefore based on the estimated current position based on the autonomous navigation means 112. The current position display 420 is displayed. At that time, if the GPS signal can be received again, the distance between the estimated current position based on the GPS signal and the position of the current position display 420 is determined.

  Further, the position comparison means 114 compares the position of the current position display 420 displayed on the display means 119 described later with map information stored in the map storage means 117 described later, so that the vehicle travels in the tunnel. It is determined whether or not. The position comparison unit 114 determines the distance between the position of the current position display 420 and the tunnel exit position.

  The display position determining means 115 is a means for determining the position where the current position display 420 is displayed. In particular, the position comparing means 114 determines whether the estimated current position based on the autonomous navigation means 112 and the estimated current position based on the GPS signal are predetermined. When it is determined that the distance is more than the distance, the position where the current position display 420 is displayed is moved stepwise from the currently displayed position to the estimated current position based on the GPS signal. A specific method for determining the display position will be described later.

  The input means 116 is composed of various keys, switches, touch panels, etc. operated by a driver of the vehicle. For example, when performing route guidance to the destination using the navigation device 10, the departure place, the destination This is for entering the location, waypoint, etc.

  The map storage means 117 stores map information including a plurality of map images having different scales from road node data whose nodes are nodes such as road branching points, and road link data whose paths are links between the nodes. Remember. The road node data includes road node numbers, position coordinates, number of connection links, branch point names, etc., and route guidance that provides route guidance such as turning left and right and straight ahead at a guide point that is a predetermined distance away from the branch point. Data and position coordinates of the guide point are stored.

  The road link data includes a road node number as a start point and an end point, a road type, a link length (link cost) as distance information between nodes, a required time, the number of lanes, a road width, and the like. Further, data such as bridges, tunnels, railroad crossings, and toll gates are added to the road link data as link attributes. The road type is information including distinction between elevated roads and underpass roads, distinction between expressways and toll roads, distinction between national roads and prefectural roads.

  Further, the map storage means 117 stores background data including facility data including water system data such as coastlines, lakes and rivers, administrative boundary data, facility locations including parking lots, facility shapes, facility names, and the like. ing.

  Further, the map storage means 117 stores map information for indicating a travel route of the vehicle, a guide route to the destination, a travel distance to the destination, and a travel time. In addition, the map information identifies locations where GPS signals cannot be received, such as tunnels, building streets, underground roads, and locations where GPS signals cannot be received, such as tunnel entrances and entrances of underground roads, or GPS signals The position where reception is possible is also included. The information on whether or not the GPS signal can be received is determined so as to be updated to reflect whether or not the GPS signal has been received when the vehicle passes through the location. May be.

  When the user inputs a destination using the input unit 116, the route search unit 118 refers to the map information stored in the map storage unit 117, and reaches the destination from the current location or the departure point designated by the user. It searches for the optimum guide route.

  The search for the guide route searches for links and nodes from the road node corresponding to the current position or starting point to the road node corresponding to the destination by various methods such as Dijkstra method, and the link length (link cost) and required By accumulating time and the like, a route having the shortest total link length (travel distance) or total required time is set as a guide route, and road nodes and links belonging to the route are provided as guide route data.

  The display means 119 is for displaying a map image, a guide route image, a mark indicating the current position of the vehicle (current position display 420 in the present embodiment) and the like so that the user can visually recognize it, such as a liquid crystal display. Consists of. The display unit 119 may function as the input unit 116 including a touch sensor. In this case, selection input is performed when the user touches an icon displayed on the display.

  Next, the display of the current position in the navigation device 10 of the present invention will be described with reference to FIGS. 2 and 3 are flowcharts showing the display operation of the current position near the tunnel exit in the navigation device 10 according to the present embodiment. FIG. 4 is a conceptual diagram of the correction of the display position performed by the navigation device 10 near the tunnel exit according to the flowchart of FIG. FIG. 5 is a flowchart showing the display operation of the current position when the current position display 420 is ahead of the actual vehicle position near the tunnel exit in the navigation device 10 according to the present embodiment. It is a conceptual diagram of correction of the display position which the navigation apparatus 10 performs in the tunnel exit vicinity according to the flowchart of FIG. In the following description, an automobile 410 (see FIG. 4) will be described as an example of a vehicle.

  First, as shown in FIG. 4A, consider a case where an automobile 410 equipped with the navigation device 10 of this embodiment is traveling on a road where GPS signals from the GPS satellite 400 can be received. FIG. 4 shows only one GPS satellite 400, but there are actually a plurality of GPS satellites 400.

  In step S <b> 201, the GPS receiving unit 111 receives a GPS signal from the GPS satellite 400. Next, in step S202, the current position calculation unit 113 calculates an estimated current position based on the received GPS signal. At this time, the current position calculation means 113 may calculate an estimated current position based on the autonomous navigation means 112 based on an output signal of the autonomous navigation means 112 such as an acceleration sensor or a gyro sensor mounted on the automobile 410. .

  In step S203, the display position determination unit 115 determines a position for displaying the current position based on the estimated current position based on the GPS signal calculated by the current position calculation unit 113, and displays the current position display 420 on the display unit 119. To do. In FIG. 4A, the traveling direction is indicated by a triangle as the current position display 420, and a mark surrounded by a circle is used. The current position display 420 is displayed at substantially the same position as the actual position of the automobile 410.

Next, in step S204, it is determined whether or not the automobile 410 has entered the tunnel. This is determined by the position comparison unit 114 comparing the position of the current position display 420 displayed on the display unit 119 with the map information stored in the map storage unit 117.
In addition, when a GPS signal cannot be received near the tunnel, it can be determined that the vehicle has entered the tunnel. If it is not determined that the vehicle has entered the tunnel, the process returns to Step S201, and Steps S201 to S204 are repeated.

  If it is determined in step S204 that the automobile 410 has entered the tunnel, the process proceeds to step S205. This state is shown in FIG. At this time, the GPS receiving means 111 of the automobile 410 cannot receive the GPS signal from the GPS satellite 400. In step S205, the current position calculation unit 113 calculates the estimated current position based on the autonomous navigation unit 112, thereby calculating the current position of the automobile 410 in the tunnel. In the subsequent step S206, the display position determination means 115 displays the current position display 420 with the estimated current position based on the autonomous navigation means 112 as the current position of the automobile 410. In FIG. 4B, the current position display 420 is displayed at a position slightly deviated from the actual position of the automobile 410, but this is caused by an error of the acceleration sensor or the gyro sensor. This error can be caused by various factors, such as errors due to aging and temperature, errors due to road gradients and road conditions, and errors due to mounting methods such as mounting angles for portable navigation equipped with acceleration sensors and gyro sensors. .

  When the navigation device 10 does not include the autonomous navigation means 112 and is not equipped with an acceleration sensor, a gyro sensor, or the like, the estimated current position based on the GPS signal calculated before entering the tunnel and the previous position The current position calculation means 113 calculates the speed of the automobile 410 when entering the tunnel based on the estimated current position based on the GPS signal, and the display position determination means 115 calculates the current position in the tunnel of the automobile 410 based on the calculated speed. It may be determined.

  In step S207, the GPS receiving unit 111 determines whether a GPS signal is received. When the GPS signal is not received, the processes in steps S205 to S207 are repeated. If it is determined in step S207 that a GPS signal has been received, the process proceeds to step S208.

  In step S208, based on the GPS signal received by the GPS receiving unit 111 from the GPS satellite 400, the current position calculating unit 113 calculates an estimated current position based on the GPS signal. Next, in step S209, the position comparison unit 114 compares the position of the current position display 420 displayed on the display unit 119 with the estimated current position based on the GPS signal received in S207, and calculates the distance.

  In step S210 of FIG. 3, it is determined whether or not the difference between the position of the current position display 420 and the estimated current position based on the GPS signal is 50 m or more. If the difference is less than 50 m, the process proceeds to step 218, where 50 m or more. In this case, the process proceeds to step S211. In step S211, it is further determined whether or not the difference between the position of the current position display 420 and the estimated current position based on the GPS signal is 100 m or more.

  In the case of FIG. 4C, the GPS signal from the GPS satellite 400 could be received when the automobile 410 approached the tunnel exit. Up to now, the automobile 410 has displayed the current position display 420 based on the estimated current position based on the autonomous navigation means 112. Here, the estimated current position based on the GPS signal can be obtained, and FIG. Then, the estimated current position based on the GPS signal can be obtained at the tunnel exit. However, the position of the current position display 420 at this time is a position delayed by 75 m from the estimated current position based on the GPS signal. In this case, since the difference between the position of the current position display 420 and the current position based on the GPS signal is 50 m or more and 100 m or less in the processes of step S210 and step S211, the process proceeds to step S215.

  In step S215, the display position determination means 115 determines the position where the current position display 420 is displayed as a position shifted 10 m backward from the estimated current position based on the GPS signal, and displays it on the display means 119. The relationship between the current position based on the GPS signal of the automobile 410 at this time and the position of the current position display 420 displayed on the display means 119 is shown in FIG. In FIG. 4D, a current position display 420 is displayed 10 m behind the estimated current position based on the GPS signal.

  In the subsequent step S216, the GPS receiving unit 111 receives the GPS signal from the GPS satellite 400, the current position calculating unit 113 calculates a new estimated current position based on the GPS signal in step S217, and the estimation calculated in step S218. The current position is set as the current position and displayed on the display unit 119 as a current position display 420. The state at this time is shown in FIG. In FIG. 4E, the estimated current position based on the GPS signal and the current position display 420 are displayed at the same position.

  In Step S210 and Step S211, when it is determined that the difference between the position of the current position display 420 and the estimated current position based on the GPS signal is 100 m or more, the process proceeds to Step S212. This situation is shown in FIG. 4 (f). In FIG. 4F, the GPS signal from the GPS satellite 400 can be received when the automobile 410 approaches the tunnel exit, and the estimated current position based on the GPS signal can be obtained at the tunnel exit. The position 420 is at a position delayed by 120 m from the estimated current position based on the GPS signal.

  In step S212, the display position determination unit 115 determines the position at which the current position display 420 is displayed as a position shifted 20 m backward from the estimated current position based on the GPS signal, and displays the position on the display unit 119. The relationship between the estimated current position based on the GPS signal of the automobile 410 at this time and the position of the current position display 420 displayed on the display means 119 is shown in FIG. In FIG. 4G, a current position display 420 is displayed 20 m behind the position of the automobile 410 (estimated current position based on GPS signals).

  Next, in step S213, the GPS receiving unit 111 receives a GPS signal from the GPS satellite 400, and in step S214, the current position calculating unit 113 calculates a new estimated current position based on the GPS signal.

  Next, in step S215, the position where the display position determining means 115 displays the current position display 420 is determined as a position shifted 10 m backward from the new estimated current position based on the GPS signal received in S213, and the display means 119 is displayed. indicate. The relationship between the estimated current position based on the GPS signal of the automobile 410 at this time and the position of the current position display 420 displayed on the display means 119 is shown in FIG. In FIG. 4H, a current position display 420 is displayed 10 m behind the position of the automobile 410 (estimated current position based on the GPS signal).

  In the subsequent step S216, the GPS receiving unit 111 receives the GPS signal from the GPS satellite 400, the current position calculating unit 113 calculates a new estimated current position based on the GPS signal in step S217, and the estimation calculated in step S218. The current position is set as the current position and displayed on the display unit 119 as a current position display 420. The state at this time is shown in FIG. In FIG. 4I, the position of the automobile 410 (the estimated current position based on the GPS signal) and the current position display 420 are displayed at the same position.

  If it is determined in step S210 that the distance between the estimated current position based on the GPS signal and the current position display 420 is less than 50 m, the process proceeds to step S218, and the estimated current position based on the GPS signal is set as the current position. The position display 420 is displayed and the process of the present invention is terminated.

  After that, the current position display 420 is displayed based on the estimated current position based on the GPS signal or the estimated current position based on the autonomous navigation means 112 as before.

  In the above embodiment, each time the estimated current position based on the GPS signal is calculated, the current position display 420 is described so as to gradually approach the estimated current position based on the calculated GPS signal. As described above, the estimated current position based on the autonomous navigation means 112 is calculated in a shorter cycle than the estimated current position based on the GPS signal, and the position of the current position display 420 while the estimated current position based on the GPS signal is calculated, When it is determined based on the estimated current position based on the autonomous navigation means 112, the current position display 420 is displayed on the calculated autonomous navigation means 112 every time the estimated current position based on the autonomous navigation means 112 is calculated. You may make it approach the estimated present position based on stepwise. That is, every time the current position is calculated regardless of the current position calculation method, the current position display 420 may be made to approach the calculated current position step by step.

  Next, processing in the case where the current position display 420 has advanced more than the actual vehicle position in the tunnel will be described with reference to the flowchart of FIG. 5 and the conceptual diagram of FIG.

  First, as shown in FIG. 6A, an automobile 410 equipped with the navigation device 10 of this embodiment travels on a road where GPS signals from the GPS satellite 400 can be received, and then, as shown in FIG. 6B. Assume that the automobile 410 enters the tunnel. Since the processing in the navigation device 10 at this time is the same as the processing in steps S201 to S206 in FIG. 2, detailed description thereof is omitted. Within the tunnel, the estimated current position based on the autonomous navigation means 112 is calculated and displayed as a current position display 420.

  In FIG. 6B, since the output of the autonomous navigation means 112 includes an error, the position of the current position display 420 is advanced more than the position of the automobile 410. In step S501 of FIG. 5, the position comparison unit 114 calculates the distance between the position of the current position display 420 and the tunnel exit. This can be calculated by referring to the map information stored in the map storage unit 117.

  The traveling direction is determined from the history of the estimated current position based on the output of the gyro sensor and the GPS signal, and the position of the tunnel exit is determined by referring to the currently traveling tunnel, the traveling direction, and the map information. It is possible.

  In step S502, it is determined whether the distance between the position of the current position display 420 and the tunnel exit is a predetermined distance or less, for example, 25 m or less. Calculates the estimated current position based on the autonomous navigation means 112 at a speed decelerated from the acceleration calculated based on the acceleration of the automobile 410 or the acceleration calculated by the autonomous navigation means 112. For example, when the autonomous navigation means 112 calculates that the automobile 410 is traveling at a speed of 60 km / h, it is assumed that the automobile 410 is traveling at a speed of 30 km / h, and the estimated current position based on the autonomous navigation means 112 is calculated.

  That is, for example, when the current position display 420 is updated at intervals of 1 second and the automobile 410 is traveling at a speed of 60 km / h, the position that is about 17 m ahead of the position of the current position display 420 is the autonomous navigation means 112. Is calculated as the estimated current position based on the above, but only when the distance between the position of the current position display 420 and the tunnel exit is 25 m or less, even if the automobile 410 is traveling at a speed of 60 km / h, A position advanced 8 m is calculated as an estimated current position based on the autonomous navigation means 112.

  Here, the calculation method of the estimated current position based on the autonomous navigation means 112 when the distance to the tunnel exit is 25 m or less is not limited to the above, but a predetermined distance from the estimated current position based on the autonomous navigation means 112 calculated as usual. The position may be a lowered position, or may be estimated based on a predetermined speed.

  Then, based on the estimated current position based on the calculated autonomous navigation means 112, the current position display 420 is displayed on the display means 119, and the process ends.

Here, when the distance between the position of the current position display 420 and the tunnel exit is 25 m or less,
The position determination method for displaying the current position display 420 is not limited to the above, and when the distance to the tunnel exit is determined to be 25 m or less, the display position determination means 115 is related to the estimated current position based on the autonomous navigation means 112. Alternatively, a predetermined position may be determined as a position for displaying the current position display 420. The predetermined position is, for example, a position 20 m, 15 m, 10 m, or 5 m from the exit of the tunnel. This position can be obtained by referring to the map information. Then, the display position determining means 115 sets the position where the current position display 20 is displayed, for example, every 20 seconds from the exit of the tunnel to 20 m, 15 m, 10 m, and 5 m every second.

  Further, for example, if the acceleration of the automobile 410 calculated by the autonomous navigation means 112 or the speed calculated based on the acceleration is equal to or greater than a predetermined value, the display position determination means 115 becomes the estimated current position based on the autonomous navigation means 112. Regardless of the method, the predetermined position is determined as the position for displaying the current position display 420, and the acceleration of the automobile 410 calculated by the autonomous navigation means 112 or the speed calculated based on the acceleration is less than the predetermined value. For example, it is assumed that the current position calculation unit 113 is traveling at a low speed (acceleration calculated by the autonomous navigation unit 112 or a speed calculated based on the acceleration), and the estimated current position based on the autonomous navigation unit 112 is determined. It is good also as the method of calculating.

  By performing the above processing, the current position display 420 can be displayed lower than the current position based on the output of the actual autonomous navigation means 112.

  When the navigation device 10 does not include the autonomous navigation means 112 and is not equipped with an acceleration sensor, a gyro sensor, or the like, the estimated current position based on the GPS signal calculated before entering the tunnel and the previous position The current position calculation means 113 calculates the speed of the automobile 410 when entering the tunnel based on the estimated current position based on the GPS signal, and the display position determination means 115 calculates the current position in the tunnel of the automobile 410 based on the calculated speed. In this case, when the distance between the position of the current position display 420 and the tunnel exit is 25 m or less, based on the speed decelerated from the speed calculated by the current position calculating means 113, the vehicle Preferably, the current position within the 410 tunnel is determined.

  The state at this time is shown in FIG. 6C and FIG. In FIG. 6C, the current position display 420 is displayed at a position advanced to the tunnel exit side from the actual position of the automobile 410. The distance from the current position display 420 to the tunnel exit is 15 m. Therefore, as described above, the position at which the current position display 420 is displayed is determined using the acceleration calculated by the autonomous navigation means 112 or the speed obtained by decelerating the speed calculated based on the acceleration. And display. This state is shown in FIG. In FIG. 6D, the current position display 420 is displayed near the tunnel exit, the actual position of the automobile 410 is also near the tunnel exit, and the actual position of the automobile 410 has caught up with the current position display 420. I understand.

  As a result, it is possible to prevent the current position display 420 (estimated current position based on the autonomous navigation means 112) from running ahead in the tunnel and reaching the tunnel exit much earlier than the automobile 410, which makes the user feel uncomfortable. It will not let you.

  When the automobile 410 exits the tunnel, the navigation apparatus 10 can receive the GPS signal from the GPS satellite 400 and simultaneously obtain the output of the autonomous navigation means 112. Therefore, the actual position and the current position display of the automobile 410 can be obtained. The position 420 can be displayed in exact agreement.

  In step S502, when it is determined that the distance between the position of the current position display 420 and the tunnel exit is not less than a predetermined distance, for example, 25 m or less, the display position determination means 115 determines the estimated current based on the autonomous navigation means 112 in step S504. Based on the position, the position of the current position display 420 is determined and displayed on the display means 119, and the process ends. In addition, after the process of step S504, you may return to the process of step S501. Further, when the automobile 410 exits the tunnel, receives the GPS signal, and the estimated current position based on the GPS signal is calculated, the current position display 420 is displayed based on the estimated current position based on the GPS signal. As is conventional, the current position display 420 is displayed based on the estimated current position based on the GPS signal or the estimated current position based on the autonomous navigation means 112.

  According to the present invention, as described above, by adjusting the position at which the current position display 420 is displayed, the current that occurs when the vehicle moves from a section that cannot receive GPS signals, such as a tunnel, to a section that can receive GPS signals. The shift of the display position of the position display 420 can be solved smoothly, and the user does not feel uncomfortable.

  In the flowchart of FIG. 3 of the above embodiment, when the distance between the estimated current position based on the GPS signal and the current position display 420 is 50 m or more (Yes in S210), the estimated current position based on the GPS signal is lowered. After the display, every time the GPS signal is received and the estimated current position based on the GPS signal is calculated, the current position display 420 is brought closer to the estimated current position based on the GPS signal. However, the present invention is not limited to this. If, for example, the distance between the estimated current position based on the GPS signal and the current position display 420 is 50 m or more (Yes in S210), the display is lowered from the estimated current position based on the GPS signal, and then the predetermined time ( For example, the current position display 420 may be brought closer to the estimated current position based on the GPS signal every time 0.5 second) elapses.

  That is, based on the GPS signal received when exiting the tunnel from the time when the estimated current position based on the GPS signal received when leaving the tunnel is calculated to the time when the estimated current position is calculated based on the next GPS signal You may comprise so that the present position display 420 may approach the estimated present position in steps.

  At this time, the predetermined time is preferably calculated based on the calculation interval of the estimated current position based on the GPS signal calculated by the current position calculation unit 113 and the number of times the current position display 420 is updated to approach in steps. .

  That is, when the distance between the estimated current position based on the GPS signal and the current position display 420 is 120 m as shown in FIG. 4F of the above embodiment, in the above embodiment, first, the estimated current position based on the GPS signal is After the position display 420 is displayed 20 m lower, it is displayed 10 m lower, and the current position display 420 is displayed at the estimated current position based on the GPS signal. Times. In the above embodiment, since the calculation interval of the estimated current position based on the GPS signal calculated by the current position calculation unit 113 is one second, it is determined by dividing this by two times of updating. Time (0.5 seconds) can be calculated.

  Moreover, you may comprise this invention so that a process may be switched according to the reduced scale of the map currently displayed on the display means 119. FIG.

  That is, when the scale of the map currently displayed on the display means 119 is determined and the scale of the map displayed on the display means 119 is a wide area, the effect obtained by the present invention is small. When the scale of the map displayed on the display means 119 is detailed without performing the processing, the effect of the present invention appears remarkably, so that the processing of the present invention may be performed.

  Further, the values used in S210 and S211 in FIG. 3, S502 in FIG. 5 and the like may be changed in accordance with the scale of the map displayed on the display unit 119. For example, if the scale of the map displayed on the display unit 119 is wide, the above value is set to a large value, and if the scale of the map displayed on the display unit 119 is detailed, the value is set to a small value. As a result, if the scale of the map is wide, it is less likely to perform step-by-step display that cannot be visually recognized, thereby eliminating unnecessary processing. Moreover, even if the scale of the map is detailed, it is possible to perform a stepwise display smoothly.

  Further, in the above embodiment, the display position determining means 115 determines the position for displaying the current position display 420 based on the estimated current position based on the GPS signal or the estimated current position based on the autonomous navigation means 112. The position where the current position display 420 is displayed may be the estimated current position based on the GPS signal or the estimated current position based on the autonomous navigation means 112, and in addition, the current position calculation means 113 may calculate the estimated current position. In consideration of such processing time, a position ahead of the estimated current position based on the GPS signal or the estimated current position based on the autonomous navigation means 112 may be determined as a position for displaying the current position display 420.

  In the above flowchart, when the power-off operation of the navigation device 10 is performed via the input unit 116, the processing of the flowchart is interrupted and the power is turned off.

DESCRIPTION OF SYMBOLS 10 Navigation apparatus 100 Control means 101 CPU
102 ROM
103 RAM
DESCRIPTION OF SYMBOLS 111 GPS receiving means 112 Autonomous navigation means 113 Current position calculation means 114 Position comparison means 115 Display position determination means 116 Input means 117 Map storage means 118 Route search means 119 Display means 400 GPS satellite 410 Car 420 Current position display

Claims (6)

Display means, GPS receiving means, current position calculating means for calculating the current position based on GPS signals received by the GPS receiving means, and calculation by the current position calculating means before the GPS signal cannot be received. A display position determining means for determining a position of a current position mark displayed on the display means based on the current position,
The current position display device calculates the current position where the GPS signal is received again by the current position calculating means when the GPS signal is received again after the GPS receiving means cannot receive the GPS signal. A position comparison means for determining whether or not the calculated current position and the position of the current position mark are more than a predetermined distance;
The display position determination means moves the position of the current position mark so as to gradually approach the current position calculated by the current position calculation means when it is determined that the position comparison means is a predetermined distance or more away. A current position display device. The current position display device includes autonomous navigation means,
The current position calculation means calculates the current position based on the current position calculated before the GPS signal cannot be received and the output of the autonomous navigation means when the GPS reception means cannot receive the GPS signal, The current position display device according to claim 1, wherein the display position determining means determines the position of the current position mark based on the calculated current position.   When it is determined that the position comparison unit is separated by a predetermined distance or more, the display position determination unit adds the current position mark to the calculated current position every time the current position is calculated by the current position calculation unit. The current position display device according to claim 1, wherein the position is moved so as to approach in steps.   When it is determined that the position comparison unit is separated by a predetermined distance or more, the display position determination unit moves the current position mark so as to gradually approach the current position where the GPS signal is received again. The present position display device according to claim 1 or 2, wherein   Whether the display position determining means moves the position of the current position mark so as to gradually approach the current position calculated by the current position calculating means according to the scale of the map displayed on the display means. The present position display device according to claim 1, wherein the current position display device is switched.   6. The current position display device according to claim 1, wherein the value of the predetermined distance is changed in accordance with a scale of a map displayed on the display means.

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