JP2006220479A - Navigation apparatus for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation apparatus for a vehicle which exactly retrieves a guide course which avoids a dark path, at a low cost. <P>SOLUTION: The navigation apparatus for the vehicle includes a position detecting means which detects the current position of the vehicle, a light intensity detecting means which detects the brightness around the vehicle, a time-acquiring means for acquiring the present time, a time deciding means for deciding whether the present time is included in the night time, a degree-of-illumination deciding means for deciding whether the brightness around the detected car is less than a predetermined value, when the acquired present time is included in the night time, and a storage means for storing the current position and its circumference as a cruise difficult zone at night when the brightness around the detected car is smaller than the predetermined value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle navigation apparatus that searches for an optimum route to a destination designated by a driver.

  As the vehicle travels, the current position is detected by GPS (Global Positioning System), etc., and the current position is displayed on the display device together with the road map, and an appropriate route from the current position to the destination is displayed. A vehicle navigation device that is set and guided by a display device, an audio output device, or the like contributes to efficient and safe driving for the driver.

  In the conventional route search, the conditions that can be specified during the route search are relatively limited. The route that the user feels “optimal” varies depending on various factors such as the user's driving skill, safety awareness, passage time zone, weather, and road conditions. For example, there are users who want to prioritize traffic safety over distance and time. In addition, there are users who want to search for routes avoiding these roads in the time zone where so-called school zones and bus lanes are installed. Some users want to preferentially select a route with a street light at night or in bad weather. Conventionally, it has not been possible to realize a route search that meets such flexible requirements.

  Therefore, in order to respond flexibly to user requests for route search, for example, route search that considers safety over distance and time such that a road with a sidewalk or separation zone is preferentially selected as a route. Depending on the time, etc., by including in the conditions traffic restrictions such as school zones and bus lanes, traffic restrictions that are set at predetermined times, and seasonal traffic effects such as freezing roads, etc. In other words, a route search device that enables a route search that takes into account changing conditions, that is, a vehicle navigation device has been devised (see Patent Document 1).

JP 2003-21525 A

  In the example of Patent Document 1, it is necessary to store in advance information related to safety, such as whether a road or a separation zone is provided on a road, or traffic regulation information according to a season / time zone. For example, if this information is stored as a part of map data for roads in Japan, a huge storage area is required, which increases the cost of the vehicle navigation device. In addition, since the user does not necessarily travel all over Japan or the roads in the range stored as data, there is a problem that the corner data cannot be effectively used.

  In addition, safety-related information or traffic regulation information changes every moment, and the information at the time stored in the map data does not always match the state when the user actually traveled. It cannot be said that it provides useful information.

  For example, if you want to avoid dark roads without street lights, the conventional technology can store the presence or absence of street lights on the road, the lighting time zone of the street lights, or the daylight / sunset times of the area including the road, The actual brightness of the road cannot be memorized.

  Against the background of the above problems, an object of the present invention is to provide a vehicle navigation device that searches for a guidance route that avoids a dark road at low cost.

Means for Solving the Problems and Effects of the Invention

  The present invention provides a vehicle navigation apparatus for solving the above-described problems. That is, according to claim 1, position detection means for detecting the current position of the vehicle, illuminance detection means for detecting the brightness around the vehicle, date and time acquisition means for acquiring the current date and time, and the acquired current date and time A date and time determination means for determining whether the brightness is included in the night, an illuminance determination means for determining whether or not the brightness of the detected vehicle is below a predetermined value when the acquired current date and time is included in the night, and detection And a storage means for storing the current position and its vicinity as a night travel difficult section when the brightness of the surrounding of the vehicle is below a predetermined value.

  In the above configuration, since the illuminance detection means always acquires information related to brightness, the data related to brightness is always updated to the latest. Therefore, when some processing is performed with reference to data relating to brightness, the accuracy of the result obtained by the processing is improved.

  According to the second aspect of the present invention, the vehicle navigation apparatus of the present invention includes destination setting means for setting a destination, route search means for searching for a guide route from the current position to the destination, and the searched guide route. In the case where the night travel difficult section is included, it is possible to adopt a configuration including route re-searching means for re-searching the guide route so as not to include the night travel difficult section.

  There is a route search function as one of the functions of a conventional vehicle navigation device, but the current route is to calculate the same route regardless of driving conditions such as the date and time when the route to be searched is the same as the starting point and destination. is there. However, there are roads where the road conditions ahead are extremely difficult to understand due to the fact that there are no or few street lights when it gets dark at night, even though the actual road conditions are safe during bright daytime. The accident rate on dark roads is several times higher than on bright roads. In addition, the load on operation is large. The present invention provides a function for avoiding such a situation as much as possible by avoiding traveling on a dark road at night, reducing the probability of encountering an accident, and reducing the load on driving.

  In the vehicular navigation device of the present invention, focusing on the brightness of the road that changes with time among the constantly changing road conditions, the dark road is determined as a high risk road for the user, and the high risk road is The guide route is searched so as to avoid it. If the vehicle navigation device having the above-described configuration is used, the user can safely reach the destination without increasing the burden during driving.

  According to the third aspect of the present invention, the vehicle navigation device includes display means for displaying the electronic map data, and the display means displays the night travel difficult section with a display color or display design different from other sections. It is also possible to take a configuration to

  With the above configuration, even when a route guidance is included, even when a night difficult travel section is included in the guide route, it is possible to grasp in advance how far the night travel difficult section will be reached, so it is possible to cope with a margin . In addition, even when route guidance is not performed, it is possible to travel by selecting a route so as to avoid a section where it is difficult to travel at night, which has the effect of reducing the load during driving and avoiding accidents. .

  The purpose of providing a vehicle navigation device that accurately searches for a guidance route that avoids dark roads at low cost is to measure and store the brightness of the road with an illuminance sensor mounted on the vehicle, and store this at night. This is realized by a vehicular navigation device that searches for a guide route so as not to travel on a road that is darker than a predetermined brightness based on the brightness data.

  Hereinafter, a vehicle navigation apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an overall configuration of a vehicle navigation apparatus (hereinafter abbreviated as a navigation apparatus) 100. The navigation device 100 includes a position detector 1, a map data input device 6, an operation switch group 7, a remote control (hereinafter referred to as “remote control”) sensor 11, a voice synthesis circuit 24 for performing voice guidance, a speaker 15, a semiconductor memory device 9, A display device 10, a hard disk device (HDD) 21, a control circuit 8 connected thereto, and a remote control terminal 12 are provided.

  A position detector 1 as position detection means of the present invention includes a known geomagnetic sensor 2, a gyroscope 3, a distance sensor 4, and a GPS receiver 5 for GPS that detects the position of a vehicle based on radio waves from a satellite. have. Since these sensors 2, 3, 4, and 5 have errors of different properties, they are configured to be used while being complemented by a plurality of sensors. Depending on the accuracy, a part of the sensors described above may be used, and further, a steering rotation sensor, a wheel sensor of each rolling wheel, or the like may be used.

  The map data input device 6 is a device for inputting various data including so-called map matching data for improving the accuracy of position detection and road data representing road connections from the storage medium 20. As a storage medium, a CD-ROM or DVD is generally used because of the amount of data, but another medium such as a memory card may be used.

  The map data stores predetermined map image information for display and road network information including link information and node information. The link information is predetermined section information constituting each road, and includes position coordinates, distance, required time, road width, number of lanes, speed limit, and the like. The node information is information that defines an intersection (branch road) and the like, and includes position coordinates, the number of right / left turn lanes, a connection destination road link, and the like. In addition, data indicating whether or not traffic is possible is set in the inter-link connection information.

  As the operation switch group 7, for example, a touch switch or a mechanical switch integrated with the display device 10 is used. The touch switch includes an infrared sensor finely arranged in the vertical and horizontal directions on the screen of the display device 10, a panel portion that converts a finger contact detected by the infrared sensor into an electrical signal, and a signal processing circuit for sending the electrical signal to an external device. And a controller for controlling them. For example, when the infrared ray is blocked with a finger or a touch pen, the blocked position is detected as a two-dimensional coordinate value (X, Y). As a touch switch, an electrical circuit is wired in the X-axis direction and Y-axis direction through a gap called a spacer on a glass substrate and a transparent film, and when the user touches the film, the wiring of the pressed part is short-circuited. Therefore, a so-called resistive film method may be used in which this is detected as a two-dimensional coordinate value (X, Y). Alternatively, a so-called capacitance method may be used in which a substance that receives an electrical signal is applied to a glass surface of a transparent conductive substrate, and a change in capacitance is detected by a sensor as an electrical signal when a finger is brought close to the glass surface. Good.

  In addition to the mechanical switch and the touch switch, a pointing device such as a mouse or a cursor may be used. It is also possible to input various instructions using the voice recognition unit 30. In this method, when a voice is input from a microphone 31 connected to the voice recognition unit 30, the voice signal is subjected to voice recognition processing by a known voice recognition technique, and converted into an operation command corresponding to the result. . The voice recognition unit 30 amplifies the voice signal input from the microphone 31 to an appropriate level, A / D-converts the amplified voice signal, and then uses a known voice recognition algorithm such as a hidden Markov model. An audio signal processing device (DSP: Digital Signal Processor) for identifying, a memory or the like in which reference data for identifying audio is stored, and the DSP converts the audio signal into numerical information corresponding to the audio. After being converted, it is sent to the control circuit 8. Various instructions can be input by the operation switch group 7, the remote control terminal 12, and the voice recognition unit 30. The operation switch group 7, the remote control terminal 12, the microphone 31, and the voice recognition unit 30 correspond to the destination setting means of the present invention.

  The transceiver 13 is a device for receiving road traffic information from, for example, a VICS (Vehicle Information and Communication System) center 14.

  Further, by connecting a mobile communication device such as a mobile phone 17 or a car phone to the communication unit 19, connection to an external network is possible and connection to the Internet or the like is possible. Furthermore, by communicating with an ETC (Automatic Toll Collection System, ETC: Electronic Toll Collection) vehicle-mounted device 16, fee information received by the ETC vehicle-mounted device 16 from the ETC road device can be taken into the navigation device 100. Moreover, it is also possible to connect with an external network by the ETC onboard equipment 16. A configuration for communicating with the VICS center 14 via the cellular phone 17 or the ETC vehicle-mounted device 16 may be adopted.

  The control circuit 8 which is the date acquisition means, date determination means, illuminance determination means, route search means, route re-search means of the present invention is configured as a normal computer, and is a known CPU 81, ROM 82, RAM 83, and input / output circuit. A certain I / O 84 and a bus line 85 for connecting these components are provided. The CPU 81 controls the navigation program 21p and data stored in the HDD 21. The CPU 81 controls the reading / writing of data to / from the HDD 21. The A / D conversion unit 86 includes a well-known A / D (analog / digital) conversion circuit, and converts analog data input from the position detector 1 or the like to the control circuit 8 into digital data that can be calculated by the CPU 81, for example. It is.

  The HDD 21 may be configured to store map data. In addition, the user can independently write data to the HDD 21 in addition to auxiliary information for route guidance, entertainment information, and the like. The contents of these data can be rewritten by operating the operation switch group 7 and the remote control terminal 12 or by inputting voice from the microphone 31. It is also possible to read the map data from the storage medium 20 using the map data input device 6 and update the contents of the HDD 21. Moreover, the structure which records the data received via in-vehicle LAN (Local Area Network) 22 which exchanges data between the other control apparatuses in a vehicle may be taken.

  The semiconductor memory device 9 is constituted by a rewritable semiconductor such as an EEPROM (Electrically Erasable & Programmable Read Only Memory) or a flash memory, and information and data necessary for the operation of the navigation device 100. Is remembered. The semiconductor storage device 9 is configured such that the stored contents are retained even when the accessory switch of the vehicle is turned off, that is, the navigation device 100 is turned off.

  Further, information and data necessary for the operation of the navigation device 100 may be stored in the HDD 21 instead of the semiconductor memory device 9. Further, information and data necessary for the operation of the navigation device 100 may be stored separately in the semiconductor storage device 9 and the HDD 21. In this case, since the access speed to the semiconductor storage device 9 is higher than that of the HDD 21, a relatively frequent read / write frequency is stored in the semiconductor storage device 9, and a relatively low read / write frequency is stored in the HDD 21. Good. The contents stored in the semiconductor memory device 9 may be backed up and saved in the HDD 21. The semiconductor storage device 9 or the HDD 21 corresponds to the storage means of the present invention.

  The display device 10 which is a display means of the present invention is a known color liquid crystal display, and includes, for example, a dot matrix LCD (Liquid Crystal Display) and a driver circuit for performing LCD display control. The driver circuit uses, for example, an active matrix driving method in which a transistor is attached to each pixel so that the target pixel can be reliably turned on and off, and is based on display instructions and display screen data sent from the control circuit 8. To display. On the screen of the display device 10, the vehicle current position mark input from the position detector 1, the map data input from the storage medium 20, and additional data such as a guide route displayed on the map are displayed in a superimposed manner. At the same time, a menu button for setting route guidance, guidance during route guidance, and a screen switching operation is displayed on this screen.

  The speaker 15 is connected to a well-known voice synthesis circuit 24 connected to the I / O 34 of the control circuit 8, and the digital voice data stored in the semiconductor storage device 9 or the HDD 21 is analogized in the voice synthesis circuit 24 according to a command from the navigation program 21 p. The converted audio is sent out. In addition, the speech synthesis method stores the speech waveform as it is or after encoding it, recording and editing methods that connect them as necessary, and analyzes the speech waveform and stores it in the form converted into parameters. There are a parameter editing system for generating speech by connecting speech synthesis circuits by connecting them, a rule synthesis system for generating speech from character strings or phoneme symbol strings based on phonetic and linguistic rules, and the like.

  The vehicle speed sensor 23 includes a rotation detection unit such as a known rotary encoder. For example, the vehicle speed sensor 23 is installed in the vicinity of the wheel mounting unit to detect the rotation of the wheel and send it to the control circuit 8 as a pulse signal. The control circuit 8 converts the number of rotations of the wheel into the speed of the vehicle, calculates the current position of the vehicle and the expected arrival time to a predetermined location, and calculates the average vehicle speed for each travel section of the vehicle. A method of acquiring vehicle speed data from other in-vehicle devices via an in-vehicle LAN (Local Area Network) 22 may be used.

  The photosensor 25, which is an illuminance detection means of the present invention, is attached to the upper part of a dash panel of a vehicle, for example, and measures the brightness around the vehicle, and uses a photoconductive sensor that measures the amount of light by a change in electrical resistance. Photoconductive sensors are also used in street lamps that automatically turn on / off. As the photoconductive element, for example, cadmium sulfide (CdS), cadmium selenium (CdSe), or a mixed crystal thereof is used. The resistance value of cadmium sulfide has a characteristic that it becomes lower when the irradiation light becomes stronger and becomes higher when the irradiation light becomes weaker. The change in the electrical resistance of the optical sensor 25 is detected as a voltage value generated at both ends of the electrical resistance and input to the control circuit 8. In the control circuit 8, the voltage value from the optical sensor 25 is sent to the input port of the CPU 81 via the I / O 84. Then, the voltage value from the optical sensor 25 is converted into digital data that can be calculated by the CPU 81 in the A / D converter 86. You may use the optical sensor used for the automatic light control system which makes the headlight of a vehicle turn on automatically according to the brightness around a vehicle.

  The external data input / output device 26 includes, for example, an input / output circuit and a connector for connecting to a removable external storage device. At least a part of the contents stored in the semiconductor storage device 9 or the HDD 21 can be stored as backup data in a magneto-optical disk or the like via an external storage device.

  With this configuration, when the navigation program 21 p is activated by the CPU 81 of the control circuit 8, the navigation device 100 is operated by the driver operating the operation switch group 7 or the remote control terminal 12 or inputting voice from the microphone 31. When the route guidance process for displaying the destination route on the display device 10 is selected from the menu displayed on the display device 10, the following processing is performed.

  That is, when the driver inputs the destination based on the map on the display device 10, the current position of the vehicle is obtained based on the satellite data obtained from the GPS receiver 5, and the optimum position from the current position to the destination is determined. Processing for obtaining a guidance route is performed. Then, the guide route is displayed on the road map on the display device 10 so as to guide the driver to the appropriate route. As a method for automatically setting an optimum guide route, a method such as the Dijkstra method is known. In addition, at least one of the display device 10 and the speaker 15 provides a notification according to the guidance during operation or the operation state.

  In Dijkstra's method, link evaluation information (route calculation cost) from the current location to each node is calculated using link information, node information, and link connection information, and all route evaluation values to the destination are calculated. At the stage of completion, a link to the smallest total evaluation value is connected and a route to the destination is set. The evaluation value in this case is set according to the road length, road type, road width, number of lanes, right / left turn at the intersection, presence / absence of traffic lights, and the like. For example, the evaluation value is lower as the road width is wider, and the evaluation value is lower as the number of lanes is larger.

  The calculation of the route calculation cost at each link is performed using, for example, the following equation. Route calculation cost = link length × road width coefficient × road type coefficient × congestion level. Here, the road width coefficient is a coefficient set according to the road width, and the road type coefficient is a coefficient set according to the road type such as a toll road. The congestion level is a coefficient set according to the congestion level of the road.

  When the optimum guide route is obtained, the control circuit 8 sets a guide target point such as an intersection that turns right or left on the guide route or a building that serves as a guide mark. Then, a guidance execution point is determined as a point to be guided by voice when the vehicle approaches a certain distance with respect to the set guidance target point. For example, when the guidance target point is an intersection, a plurality of guidance execution points can be set such as 700 m before, 300 m before, 100 m before on a general road, 2 km, 1 km, 500 m before on an expressway.

  The route search process of the present invention will be described with reference to the flowchart of FIG. This process is included in the navigation program 21p executed by the CPU 81, and is repeatedly executed together with other processes of the navigation program 21p.

  First, it is checked from the date and time information whether the travel time zone is daytime. If it is daytime (S1: Yes), the process is terminated. The date and time information includes a method of using a well-known clock IC for generating date and time data incorporated in the control circuit 8, a date and time data included in the GPS signal obtained by acquiring a GPS signal from the GPS receiver 5. , A method using date / time data included in communication data with the VICS center 14, a method for obtaining date / time data obtained through communication between the ETC on-vehicle device 16 and the ETC roadside device, or the like may be used.

  Whether it is daytime is determined based on the sunrise / sunset times of major cities nationwide stored in the storage medium 20 or the HDD 21. In other words, the sunrise / sunset times of the city including the current position of the vehicle detected by the position detector 1 or the city closest to the current position of the vehicle are used for the determination.

  When the traveling time zone is not daytime (S1: No), it is checked whether the optical sensor 25 is connected to the vehicle. A voltage signal from the optical sensor 25 is sent to the input port of the CPU 81 via the I / O 84. If the voltage value output from the optical sensor 25 with respect to the change in brightness is adjusted in advance to be in the range of 0.5 V to 4.5 V, the A / D conversion unit 86 also converts it to a corresponding value. . For example, when the A / D converter 86 performs A / D conversion with a data length of 8 bits, 0.5V to 4.5V is represented by 19H to 0EAH (“H” means a hexadecimal number below) the same). Therefore, when the A / D conversion value is in the range of 00H to 18H or 0EBH to 0FFH, it can be determined that the optical sensor 25 is abnormal or not connected.

  When the optical sensor 25 is connected to the vehicle and the optical sensor 25 is normal (S2: Yes), the voltage value from the optical sensor 25 is acquired to determine the brightness around the vehicle (S3). Then, a threshold is set for the brightness data after A / D conversion to classify whether the running road is bright or dark. The threshold value may be set by the user.

  If the road being traveled is classified as a “dark” road (S4: Yes), information “dark at night” is added to the travel position of the map data stored in the storage medium 20 (S5). . Further, information “dark at night” is added to the link information including the travel position (S6).

  FIG. 3 shows an example of information regarding the brightness of the road included in the link information. The brightness is converted into a cost. This cost is added to the originally set link cost. The brightness A / D conversion value detected by the optical sensor 25 may be stored. The brightness may be divided into three levels as shown in FIG. “Darker” roads cost more. The user may be able to set which brightness is “dark at night”. In addition to the day / night classification, for example, information on brightness for each time zone such as every hour may be stored.

  When the user sets the destination and executes the route search (S7: Yes), the guide route is searched by the above-mentioned Dijkstra method. At this time, if any of the link information of the searched guide route includes information “dark at night” (S8: Yes), the guide route is searched again so as not to include the link, that is, the road section. (S9). If the cost value included in the link information of the road determined to be dark is sufficiently high, it is possible to search the guide route so as not to include the section of the road “dark at night” in one search. .

  Then, on the map displayed on the display screen of the display device 10, the road “dark at night” is displayed with a different display color or display design from other roads (S10). For example, a road that is “dark at night” has a lower brightness than other roads, or the display color of a road that is “dark at night” is a black color so that it does not exist on the map. It is displayed so that the user can select a road other than the “dark at night” road and be guided.

  In the above embodiment, various settings by the user are performed as follows. When the user operates the operation switch group 7 or the remote control terminal 12 or inputs a voice from the microphone 31, the function setting menu is displayed on the display device 10 from the menu displayed on the display device 10, and a dark road is displayed from the menu. Select and display the setting screen for the function to be avoided. Then, each item is selected and set. The selected / set contents are stored in a predetermined area of the semiconductor memory device 9 or the HDD 21.

  Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited to these embodiments, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

The block diagram which shows the structure of a navigation apparatus. The flowchart for demonstrating the route search process of this invention. The figure which shows the example in which the cost of a link is set according to a brightness.

Explanation of symbols

1 Position detector (position detection means)
7 Operation switch group (Destination setting means)
8 Control circuit (date acquisition means, date determination means, illuminance determination means, route search means, route re-search means)
9 Semiconductor memory device (memory means)
10. Display device (display means)
12 Remote control terminal (Destination setting means)
20 Storage medium 21 Hard disk device (HDD, storage means)
25 Optical sensor (illuminance detection means)
30 Voice recognition unit (Destination setting means)
31 Microphone (Destination setting means)
100 Navigation device

Claims (3)

Position detecting means for detecting the current position of the vehicle;
Illuminance detection means for detecting brightness around the vehicle;
A date and time acquisition means for acquiring the current date and time;
Date and time determination means for determining whether the acquired current date and time is included in the night,
Illuminance determination means for determining whether the brightness of the detected vehicle is below a predetermined value when the acquired current date and time is included at night,
Storage means for storing the current position and the vicinity thereof as a night travel difficult section when the detected brightness around the vehicle is lower than a predetermined value;
A vehicle navigation device comprising: Destination setting means for setting the destination;
Route search means for searching for a guide route from the current position to the destination;
A route re-search means for re-searching the guide route so as not to include the night difficult travel section when the searched difficult route includes the night travel difficult section;
The vehicle navigation device according to claim 1, comprising: Display means for displaying the electronic map data;
The vehicle navigation device according to claim 1 or 2, wherein the display means displays the difficult-to-run section at night by a display color or display design different from other sections.

Images