JP3591112B2 - Car navigation system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a car navigation device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a car navigation device detects the current position of a vehicle using radio navigation or autonomous navigation such as GPS and beacon, and uses a map database to determine which position on the map corresponds to the current position. Identify and display on the display screen.
[0003]
[Problems to be solved by the invention]
By the way, when the power of the car navigation device is turned off, the current position is not updated even if the vehicle moves thereafter. Therefore, for example, when a vehicle is transported on a sea route by a ferry boat, immediately after the power is turned on again at the destination port, only the map of the departure port and the vehicle position at the time of power off may be displayed.
[0004]
In a system using autonomous navigation, if the starting point is wrong, it is impossible to provide a correct traveling route guidance. Therefore, in order to provide travel guidance from the destination port, it is necessary to operate an input panel or the like to perform an operation for re-specifying the current position coordinates of the vehicle by the latitude and longitude, which can be easily adjusted. There is a problem that can not be.
[0005]
Even when using GPS navigation, the current position of the vehicle may not be able to be specified depending on the time zone. Therefore, in order to immediately provide travel guidance from the port of departure, an operation for specifying the current position coordinates of the vehicle must be performed.
[0006]
In recent systems, radio navigation is often used together rather than autonomous navigation alone. Therefore, if information from a GPS satellite becomes available without performing the above-described operation, correct display is possible. However, especially when the destination port is the first land, the time during which this travel guidance is unavailable becomes very problematic.
[0007]
Therefore, an object of the present invention is to enable a vehicle to provide a correct traveling route promptly without performing a complicated operation even when a vehicle moves without traveling on a navigation route or the like.
[0008]
[Means for Solving the Problems]
The car navigation device of the present invention stores a power-off point, and predicts a point at which a vehicle can reach without turning on the power-off point based on information such as a route when the power is turned on. The power-on point is determined from the reachable point and the power-off point.
[0009]
Here, the information such as the route is not limited to sea transport, but may be a route in rivers, lakes and marshes, and a transport route by air transport or rail transport. Both are routes on which vehicles do not normally move, and when vehicles move on these transportation routes, they are common in that they will be moved without traveling by themselves on ships, aircraft or railway vehicles. is there.
[0010]
As a specific aspect of the present invention, when the point where the power is turned off is a place such as a port, an airport, a freight station, etc., a point that can be reached without the vehicle traveling by itself based on the route from there is predicted. You do it. In this case, the port or the like, which is the power-off point, may be considered as one of the reachable points. When determining the power-on point, it is sufficient that at least the power-off point is one of the candidates. This is because the vehicle may only be parked at a port or the like.
[0011]
In addition, as a specific method of determining the power-on point, after the vehicle starts traveling, the matching of the traveling locus of the vehicle starting from the reachable point and the power-off point with the road shape in the map database is performed. The power-on point can be determined based on the situation. In this case, although the point cannot be specified immediately after the power is turned on, the shape of the road that extends from the port of departure and the port of destination is usually less consistent, so during the short time after the start of traveling The traveling route guidance can be performed based on the correct current position. In addition, since it is sufficient to use a pattern matching method, the processing can be automatically performed, and the driver's hand is not bothered.
[0012]
However, the configuration may be such that the reachable point and the power-off point are displayed as candidates for the power-on point, and the power-on point is determined after the selection, without performing complete automation.
In this case, the candidate place names of the power-on point are displayed in a list, and a number or the like is input with the operation keys, so that the system can automatically identify the latitude and longitude of the vehicle based on the place name entered by the key. The correspondence between the place names such as ports and the latitude and longitude may be stored in a database.
[0013]
Alternatively, the display screen may be divided into a plurality of windows to display a map corresponding to each candidate of the power-on point, and a selection may be made by designating one of the windows. In these modes, although a little driver's operation is required, it is not necessary to input the latitude and longitude, and the burden on the driver is very small. Conversely, if attention is paid to the time required to start the correct travel route guidance, there is an advantage that the time is shorter than that of the fully automated method using the pattern matching described above.
In addition, the reachable point prediction means may be configured as a means for predicting a reachable point in consideration of a relationship between information on a departure / arrival timetable of the vehicle transportation means and a power-off time or a power-on time.
[0014]
According to the present invention, when the power is turned on, whether or not the vehicle is moving after the power is turned off is predicted based on information such as a route, so that when traveling on a ferry route, a traveling route from a destination Guidance can be started promptly and correctly.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, examples will be described to clarify the embodiments of the present invention.
As shown in FIG. 1, the car navigation device 10 according to the embodiment includes a GPS receiver 11 that receives a signal from a GPS satellite, a wheel speed sensor 13, and a direction sensor 15 including a yaw rate sensor or a geomagnetic sensor. A CD-ROM drive unit 17 for driving a CD-ROM storing a map database and a data setting / display device 19 are connected. Here, the data setting / display device 19 includes a screen for displaying a map, a speaker for making an announcement by voice, and an operation panel for inputting various commands, numerical values, and the like.
[0016]
The car navigation device 10 calculates a GPS navigation that calculates an absolute position of a vehicle based on a radio wave received by a GPS receiver 11, and determines a moving direction and a moving amount of the vehicle based on detection signals of a wheel speed sensor 13 and a direction sensor 15. This is a combination of autonomous navigation performed by calculation. Then, the current position of the vehicle is calculated by the GPS navigation while the radio wave from the GPS satellite can be received, and by the autonomous navigation while the radio wave cannot be received, and the driving route is guided by superimposing the current position on the map database in the CD-ROM. It has become. The map database stored in the CD-ROM contains information on the ports and routes of the ferry routes. In addition, the car navigation device 10 has a non-volatile memory for storing the current position of the vehicle when the power is turned off.
[0017]
The car navigation device 10 is configured to provide a traveling route guidance in a procedure as shown in FIG.
First, when the system is started by turning on the power, the vehicle position at the time of turning off the power (the power-off point) stored in the non-volatile memory is read (S10). Next, it is determined whether or not this power-off point is a ferry pier by comparing it with information on a ferry route in a map database (S20). If it is determined that the vehicle is not at the ferry port, the power-off point read in S10 is set as it is as the vehicle position (power-on point) at power-on (S30), and the corresponding map is read from the map database and displayed on the screen. Then, the power-on point is displayed thereon (S40). When the vehicle starts running, the current position of the vehicle is moved on the map displayed on the screen according to the GPS navigation and the autonomous navigation (S50). If GPS navigation can be used, the GPS navigation has priority. In autonomous navigation, errors are corrected by further performing map matching.
[0018]
On the other hand, if the power-off point is the ferry landing (S20 = YES), a landing port where vehicles can be reached by ferry transportation is predicted based on the ferry route extending from the landing (S110), and the prediction is made. Then, the lower landings of all the destination ports and the ferry landings, which are the power-off points, are set as candidates for the power-on points (S120). Then, when the vehicle starts running, the running trajectory is calculated in accordance with the GPS navigation and the autonomous navigation using the candidates for the respective power-on points as starting points (S130), and the calculated running trajectories and the respective power-on point candidates are used as the starting points. The pattern matching with the road shape on the growing map is executed (S140). As a result of this pattern matching, the starting point of the traveling route in which a mismatch state equal to or greater than a predetermined value is deleted from the power-on point candidates (S150, S160). Then, when there is only one power-on point candidate, the candidate is determined as the power-on point (S170, S180), the corresponding map is read out and displayed on the screen, and the map is displayed on the map from the power-on point. The current position of the vehicle is displayed according to the travel route calculation result (S190). Thereafter, the process proceeds to S50, in which the traveling route calculation is repeated, and the current position of the vehicle on the map is moved according to the traveling situation. During the processing from S110 to S180, the screen may not be displayed, or the screen may be divided into a plurality of windows and the traveling route from each candidate point may be displayed at the same time. Alternatively, a display may be made assuming that the passenger has not boarded the ferry.
[0019]
Then, the current position of the vehicle calculated in S50 is updated while being overwritten in the nonvolatile memory (S60). Thus, the contents of the nonvolatile memory when the power is turned off naturally become the power-off point.
A specific example will be described with reference to FIG. It is assumed that the power is turned off at the ferry landing and then turned on. At this time, it is assumed that three ferry routes have been extended from the pier. Then, the illustrated destinations (1) to (3) and the ferry pier are set as candidates for the power-on point. Next, assuming that the traveling trajectory of the vehicle after arrival at the ferry is as shown on the left side of the figure, a difference in the pattern from the road shape starting from the ferry pier soon appears, and this is immediately removed from the candidates. Similarly, the destination (3) also has a pattern mismatch at an early stage, and is therefore excluded from the candidates. Then, when the vehicle travels a little, the destination (1) is removed due to the pattern mismatch. As a result, the travel locus calculation result based on the destination (2) is adopted as the correct current position. In this way, the traveling route guidance starting from the lower landing of the destination port of the ferry route is automatically started immediately.
[0020]
Next, a second embodiment will be described.
In this embodiment, the traveling route guidance is performed according to the procedure shown in FIG. Since steps S10 to S60 in the figure are completely the same as those in the first embodiment, the description will be omitted with the same step numbers, and only different parts will be described in detail.
[0021]
When the power-off point is the ferry landing (S20 = YES), the lower landing at which the vehicle can be reached by ferry transportation is predicted based on the ferry route extending from the landing (S210), and the prediction is made. The drop-off places of all destination ports and the ferry piers, which are power-off points, are displayed in a list as candidates for power-on points (S220). Then, the system waits for the driver to specify the list number (S230). When the list is specified, the point is determined as the power-on point, the corresponding map is read out and displayed on the screen, and the power-on point is displayed on the map. Is displayed (S240). Thereafter, the process proceeds to S50, in which the traveling route calculation is repeated, and the current position of the vehicle on the map is moved according to the traveling situation.
[0022]
According to this embodiment, complete automation cannot be performed, but there is an advantage that a correct map cannot be displayed until the first embodiment runs a little, but a correct map can be displayed immediately. The operation for this is not a troublesome and complicated operation such as inputting the latitude and longitude, but is simply performed by designating the list number by key input.
[0023]
Although several embodiments have been described for the embodiments of the present invention, the present invention is not limited to these embodiments, and can be implemented in various other modes.
For example, the present invention can be applied not only to a ferry route but also to a case where a vehicle is moved by air transport or a vehicle is moved by rail transport. Further, in the above-described embodiment, for example, all destinations are extracted and set as candidates according to all routes from the ferry landing. The configuration may be such that the candidates are further narrowed down based on the relationship with the time or the power-on time.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an entire apparatus configuration as an embodiment of the present invention.
FIG. 2 is a flowchart showing a procedure of traveling route guidance according to the first embodiment.
FIG. 3 is an explanatory diagram showing the operation of the first embodiment.
FIG. 4 is a flowchart showing a procedure for traveling route guidance according to a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Car navigation device, 11 ... GPS receiver, 13 ... Wheel speed sensor, 15 ... Direction sensor, 17 ... CD-ROM drive unit, 19 ... Data setting / display device.

Claims (3)

In a car navigation device having a function of specifying the current position of a vehicle on a map using a map database,
A power-off point storing means for storing a power-off point; and a power-on point in which a vehicle can reach without traveling by itself from the stored power-off point based on information such as a route when the power is on. Reachable point prediction means for predicting
Power-on point determination means for determining a power-on point from the predicted reachable point and the power-off point ,
After the vehicle starts running, the power-on point determination means turns on the power based on a matching state between the traveling locus of the vehicle starting from each of the reachable point and the power-off point and the road shape in the map database. A car navigation device configured as means for determining a point . In a car navigation device having a function of specifying the current position of a vehicle on a map using a map database,
A power-off point storing means for storing a power-off point; and a power-on point in which a vehicle can reach without traveling by itself from the stored power-off point based on information such as a route when the power is on. Reachable point prediction means for predicting
Power-on point determination means for determining a power-on point from the predicted reachable point and the power-off point,
The power-on point determination means is configured as means for displaying the reachable point and the power-off point as candidates for a power-on point, and determining a power-on point after selection.
A car navigation device characterized by the above-mentioned . The car navigation device according to claim 1 or 2,
The reachable point prediction means is configured as a means for predicting a reachable point in consideration of a relationship between information regarding a departure / arrival timetable of the vehicle transportation means and a power-off time or a power-on time.
A car navigation device characterized by the above-mentioned .

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