Abstract:
A navigation system for use in a vehicle precludes a certain search area from a scope of a facility search based on a vehicle condition, sensor data, a vehicle travel history or the like for better serving a user by reducing a turnaround time.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based on and claims the benefit of priority of Japanese Patent Application No. 2005-336389 filed on Nov. 21, 2005, the disclosure of which is incorporated herein by reference.  
       FIELD OF THE INVENTION  
       [0002]     The present invention generally relates to a navigation system for use in a vehicle.  
       BACKGROUND OF THE INVENTION  
       [0003]     In recent years, a specific type of navigation system provides for a user a route navigation toward a desired facility based on a voice recognition technique. For example, Japanese Patent Application No. JP-A-2004-325181 discloses a navigation system that prioritizes a route navigation toward a parking space in a building when weather conditions detected by various sensors in association with a wiper system, an air conditioner or the like indicate a subject vehicle is traveling in a rain or in high temperature.  
         [0004]     Further, Japanese Patent Application No. JP-A-2005-181125 discloses a route navigation method that improves facility search efficiency by conducting a facility search from among facility candidates existing in a preferred range of search direction. That is, the facility search is performed only in a circular area having a predetermined radius around a current position or a specified position, or only in a user-specified direction from a specified position.  
         [0005]     Furthermore, Japanese Patent Application No. JP-A-2001-12963 discloses a route navigation method that automatically restricts a facility search area within a predetermined range based on a destination history and stopping time when the user searches for an unknown facility by using a voice input or a manual input of a location name.  
         [0006]     However, the facility search method described above includes the facility candidates in the search area that are not necessarily suitable for user&#39;s preference, individual variations, and/or vehicle conditions in a time-specific manner because the search is performed on facility data in a database prepared in advance. Therefore, the facility search efficiency is deteriorated and a search speed is compromised. In addition, unwanted facilities included in a search result reduce the user&#39;s convenience.  
       SUMMARY OF THE INVENTION  
       [0007]     In view of the above-described and other problems, the present disclosure provides a navigation system and/or a navigation method that narrows a scope of a facility search for better serving a user by improving search speed and user&#39;s convenience in a facility search.  
         [0008]     In one aspect of the present disclosure, the navigation system for use in a vehicle having a function of a facility search includes a first search area setting unit for setting a circular facility search area having a predetermined radius centered at a current position of the vehicle when a facility is searched for in a vicinity of the current position of the vehicle on a condition that a map matching function is not in effect and a navigation route is not being provided, a second search area setting unit for setting a directional facility search area toward a traveling direction when a facility is searched for in a vicinity of the current position of the vehicle on a condition that the map matching function is in effect and the navigation route is not being provided, and a third search area setting unit for setting a proximity facility search area along the navigation route when a facility is searched for in a vicinity of the current position of the vehicle on a condition that the navigation route is being provided. In this manner, the navigation system narrows a scope of a facility search based on an operation condition of the vehicle such as a condition of map matching, a navigation route or the like, thereby enabling a search of a desired facility in a reduced turnaround time. For example, a facility search is conducted in a search area that has a circular shape having a predetermined radius centered at a current vehicle position, a directional area having a predetermined distance toward a destination, or a proximity area within a predetermined distance range from a current route, a frequently traveled area based on a travel history, a proximity area within a predetermined distance range from a specified position/area/road or the like. Further, the circular facility search area may be used in the facility search when a facility is searched for in an area that is not in the vicinity of the current vehicle position.  
         [0009]     In another aspect of the present disclosure, the navigation system includes a search condition determination unit for determining whether a search area condition of the facility search is set by using one of the first search area setting unit, the second search area setting unit, and the third search area setting unit. In this manner, user&#39;s preference of how to determine a scope of the facility search is reflected in the facility search.  
         [0010]     In yet another aspect of the present disclosure, the navigation system includes a time input unit for inputting time and date information, and a time-specificity setting unit for imposing time specificity on a search area condition of the facility search based on the time and date information inputted by the time input unit. In this manner, the scope of the facility search is further adapted to user&#39;s needs for having a reduced turnaround time by considering a time and a date of the facility search. For example, the facility search in a work hour or in a commuting hour may limit a scope of the facility search to fast food restaurants or the like because a break time allowed in the searched facility is relatively short in the work/commuting hour. On the other hand, the scope of the facility to be searched may be limited to full-service restaurants in a shopping mall or the like when the facility search is performed on holidays, or in a long distance travel.  
         [0011]     In still yet another aspect of the present disclosure, the navigation system includes a weather condition input unit for inputting weather condition information, and a weather-specificity setting unit for imposing weather specificity on a search area condition of the facility search based on the weather condition information inputted by the weather condition input unit. In this manner, the scope of the facility search is further adapted to user&#39;s needs for having a reduced turnaround time by considering weather conditions at the time of the facility search. For example, the facility search precludes an inconvenient place and situation such as an outdoor parking space on a rainy day, a facility closely located to a school at a going-to-school or coming-back-from-school time. In addition, in a situation such as a holiday shopping for various items in the afternoon of a rainy day, the scope of the facility search includes facilities (i.e., stores) on a not-too-far location in the facility search for a sufficient free indoor parking space.  
         [0012]     In still yet another aspect of the present disclosure, the navigation system includes a destination history storage unit for storing a destination history of the vehicle, a route history storage unit for storing a route history of the vehicle, and a historical condition setting unit for imposing specificity of the destination history and the route history on a search area condition of the facility search by referring to the destination history storage unit and the route history storage unit. In this manner, the facility search yields a search result having a higher visiting probability by the user in the reduced turnaround time.  
         [0013]     In still yet another aspect of the present disclosure, the navigation system includes a voice recognition unit for recognizing a user&#39;s voice, and a control unit for controlling a functional operation according to the users voice recognized by the voice recognition unit. In this manner, the user can interactively narrow the scope of the facility search of the navigation system in a directive manner.  
         [0014]     The aspects of the present disclosure described above may be provided as a facility search method implemented by a process in the navigation system or in a similar apparatus. Each of the above described aspects is thereby realized in the process in the navigation system in the same manner. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which:  
         [0016]      FIG. 1  shows a block diagram of a navigation system in a first embodiment of the present disclosure;  
         [0017]      FIG. 2  shows a block diagram of software used in the navigation system in  FIG. 1 ;  
         [0018]      FIG. 3  shows a facility data table used in a map database in  FIG. 2 ;  
         [0019]      FIG. 4  shows an illustration of a facility retrieval range in a case without a map matching and a navigation route in effect in a proximity of a current position, in a case in a proximity of a position different from the current position, or in a similar situation;  
         [0020]      FIG. 5  shows an illustration of a facility retrieval range in a case with a map matching without a navigation route in effect in a proximity of a current position, or in a similar situation;  
         [0021]      FIG. 6  shows an illustration of a facility retrieval range in a case with a map matching and a navigation route in effect in a proximity of at a current position, or in a similar situation;  
         [0022]      FIG. 7  shows an illustration of a facility retrieval range in a case with a history route, or in a similar situation;  
         [0023]      FIG. 8  shows a flowchart of a retrieval range setting process in the first embodiment; and  
         [0024]      FIG. 9  shows a flowchart of a sensor data acquisition process in  FIG. 8 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     The present invention will be described in detail with reference to various embodiments, in which the same reference numerals designate same or similar members.  
         [0026]      FIG. 1  is a circuit block diagram of a navigation apparatus  100  according to a first embodiment of the present invention. The navigation apparatus  100  according to the first embodiment has a main portion including: a position detector  1 ; a map data input unit  6 ; an operation switch group  7 ; a control circuit  8 ; a nonvolatile memory  9 ; a display unit  10 ; a touch panel  11 ; a remote control (hereinafter referred to as a remote control) sensor  12 ; a remote control terminal  13 ; a voice recognition unit  14 ; a microphone  15 ; a voice synthesizing circuit  16 ; a loudspeaker  17 ; LAN (Local Area Network) I/F (Interface)  18 ; a storage medium  19 ; a hard disk drive (HDD)  20 ; and a transceiver  21 . In  FIG. 1 , the reference numeral  101  designates various sensors of the vehicle;  102 , on-vehicle real-time information apparatuses;  103 , internal apparatuses; and  104 , an information center.  
         [0027]     The position detector  1  includes a well-known geomagnetic sensor  2 , a gyroscope  3  that detects a rotational angular velocity of the vehicle, a distance sensor  4  that detects a mileage of the vehicle, and a GPS (Global Positioning System) receiver  5  that detects position of the vehicle based on radio waves from satellites, to calculate absolute coordinates on the earth. These sensors  2 ,  3 ,  4 , and  5 , which respectively have errors of different natures, are compensated by the plural sensors. Depending on precision, part of the sensors described above may be used, and furthermore, a rotation sensor of steering wheel, a wheel sensor of each rolling wheel, e.g., a vehicle speed sensor or the like, may additionally be used.  
         [0028]     The input unit  6  is a storage medium reading apparatus that reads data from the storage medium  19  such as CD-ROM (Compact Disk-Read Only Memory), DVD (Digital Versatile Disk), and the like.  
         [0029]     The operation switch group  7  is composed of the touch panel  11  integrated with the display unit  10  or a mechanical switch.  
         [0030]     The control circuit  8  acquires map image information in the vicinity of absolute coordinates of the position detector  1 , and displays map image information and an own vehicle mark in the display screen of the display unit  10 . The control circuit  8 , constructed as a normal computer, includes a well-known CPU (Central Processing Unit)  81 , a ROM (Read Only Memory)  82 , a RAM (Random Access Memory)  83 , an I/O (Input/Output)  84 , an A/D (Analog/Digital) conversion unit  86 , a drawing unit  87 , and a bus line  85  that connects these components.  
         [0031]     The CPU  81  performs control according to a navigation program  20   p  and data stored in the HDD  20 . The CPU  81  controls reading or writing data from or to the HDD  20 .  
         [0032]     The ROM  82  stores a minimum of programs required to activate the navigation apparatus  100 . The ROM  82  may store a program for performing a minimum of required operations of navigation functions when the HDD  20  fails.  
         [0033]     The RAM  83  is a memory into which the CPU  81  temporarily loads an instruction and data during execution or processing of a program such as the navigation program  20   p.    
         [0034]     The A/D conversion part  86  includes a well-known A/D conversion circuit, and for example, converts analog data inputted from the position detector  1  to the control circuit  8  into digital data on which the CPU  81  can operate.  
         [0035]     The drawing unit  87  creates display screen data for displaying display data, display color data and the like stored in the HDD  20  on the display unit  10 .  
         [0036]     The nonvolatile memory  9  is composed of EEPROM (Electrically Erasable &amp; Programmable Read Only Memory) and a rewritable semiconductor memory such as flash memory, and stores information and data necessary for the operation of the navigation apparatus  100 . The nonvolatile memory  9  holds storage contents even when accessory switches of the vehicle go off, that is, the navigation apparatus  100  is turned off. Information and data necessary for the operation of the navigation apparatus  100  may be stored in the HDD  10  instead of the nonvolatile memory  9 . Furthermore, information and data necessary for the operation of the navigation apparatus  100  may be stored separately in the nonvolatile memory  9  and the HDD  20 .  
         [0037]     The display unit  10  is composed of a well-known color liquid crystal display unit. It includes a dot matrix LCD (Liquid Crystal Display), and a driver circuit (not shown) for performing LCD display control. The driver circuit employs the active matrix driving system that provides a transistor for each pixel to turn on or off a desired pixel without fail, and makes display based on a display command and display screen data fed from the control circuit  8 . As the display unit  10 , an organic EL (Electroluminescence) display unit, a plasma display unit or the like may be used.  
         [0038]     The touch panel  11  is an input apparatus attached to the display surface of the display unit  10 , and sends the coordinates of a user-touched position to the control circuit  8 . In the touch panel  11 , on the screen of the display unit  10 , electrical circuits are wired in X-axis direction and Y-axis direction with a gap called a spacer on a glass board and a transparent film. When a user touches on the film by a pointing member such as a finger, since a wiring of the pressed portion short-circuits and a voltage value changes, it is detected as two-dimensional coordinate value (X,Y). This scheme is the widely used so-called resistance film system. Also, the so-called electrostatic capacity system may be used. Furthermore, in addition to a mechanical switch, a pointing apparatus such as a mouse and the cursor may be used.  
         [0039]     The remote control sensor  12  is a receiving unit that receives radio waves from the remote control terminal  13 .  
         [0040]     The remote control terminal  13  has plural input buttons, and transmits a command or the like corresponding to an operated input button wirelessly to the remote control sensor  12  over radio waves or infrared rays.  
         [0041]     The voice recognition unit  14  processes a voice signal inputted from the microphone  15  by voice recognition technology such as the well-known hidden Markov model, makes conversion into a command or the like corresponding to the result, and outputs them to the control circuit  8 .  
         [0042]     The microphone  15  is a voice input unit that enables user-uttered words to be inputted to the control circuit  8  through the voice recognition unit  14 .  
         [0043]     The voice synthesizing circuit  16  converts digital voice data stored in the nonvolatile memory  9  or the HDD  20  into an analog voice signal according to a command of the navigation program  20   p  and outputs the converted analog voice signal. As a method of synthesizing voices, a recoding editing system is available which stores voice waveforms without changing them or stores them after encoding them and combines them as required.  
         [0044]     The loudspeaker  17  is connected to the voice synthesizing circuit  16 , and generates voice based on an analog voice signal outputted from the voice synthesizing circuit  16 .  
         [0045]     The LAN I/F  18  is an interface circuit that exchanges of the data with other on-vehicle equipments and sensors via an in-vehicle LAN (not shown in the figure).  
         [0046]     The storage medium  19  is a recording medium that stores the navigation program  20   p , the database  20   d , and the map data  20   m  and the like. As the storage medium  19 , CD-ROM and DVD are generally used because of their data amount. Other media such as a memory card may be used. Data may be downloaded via an external network. Further, for use in the navigation program  20   p , the database  20   d , the map data  20   m , and the user data  20   u , additional/update data may be transferred to the HDD  20  from the storage medium  19  by using the map data input unit  6 .  
         [0047]     The HDD  20  stores the navigation program  20   p , so-called map match data for improving the accuracy of position detection, and map data  20   m  including road data and the like representative of the connections of roads. The map data  20   m  stores predetermined map image information used for display and road network information including link information and node information and the like. The link information, which is information about sections constituting a respective road, includes position coordinates, distances, travel time, road width, the number of lanes, speed limits, and the like. The node information, which is information which defines intersections (divergence road) and the like, includes position coordinates, the number of right-turn and left-turn lanes, links to destination roads, and the like. Inter-link connection information contains data indicating whether to permit passage or the like. Auxiliary information of route guide and amusement information, and user-specific data can be written to the HDD  20  as user data  20   u . These user data  20   u  may be updated by performing an operation on the switch group  7 , the touch panel  11 , and the remote control terminal  13 , or voice input from the microphone  15 . Data and various information necessary for the operation of the navigation apparatus  100  may be stored as the database  20   d.    
         [0048]     The transceiver  21  is a communication apparatus that transmits and receives data to and from the information center  104 .  
         [0049]     The various sensors  101  include a vehicle speed sensor, a yaw rate sensor, and the like, and outputs a vehicle speed, a yaw rate, and the like to the control circuit  8 . The various sensors  101  also include a timer.  
         [0050]     The real-time information apparatuses  102  include a receiver (not shown) that receives traffic information from a traffic information infrastructure such as the Vehicle Information and Communication System (VICS) center (not shown), and cameras (not shown) that photograph the rear and sides of the vehicle, and outputs traffic information, camera pictures, and the like to the control circuit  8 .  
         [0051]     The internal apparatuses  103  include wipers, lights, an air conditioner, and the like, and inputs weather information such as precipitation, day/night distinction, and high temperatures to the control circuit  8 .  
         [0052]     The various sensors  101 , the real-time information apparatus  102 , and the internal apparatus  103  may be connected to the control circuit  8  of the on-vehicle navigation apparatus  100  directly or via the LAN I/F  18 .  
         [0053]     The information center  104  is an external apparatus that transmits and receives data to and from the on-vehicle navigation apparatus  100  through the transceiver  21 . When data on the HDD  20  is updated using wireless data communication, it is accessed through the transceiver  21  from the control circuit  8 .  
         [0054]      FIG. 2  is a block diagram showing an outline of the software construction of the navigation program  20   p . The navigation program  20   p  includes a voice input/output part  22 , an interaction control part  23 , a facility retrieval part  24 , a record management part  25 , a destination history database  26 , a traveling route history database  27 , a map database  28 , sensor information  29 , retrieval result data  30 , and a retrieval result output part  31 . The sensor information  29  is a generic name of information inputted to the control circuit  8  from the various sensors  101 , the real-time information apparatuses  102 , and the internal apparatuses  103 .  
         [0055]      FIG. 3  is a facility data table showing an example of facility data included in the map database  28  in  FIG. 2 . The facility data includes plural records each including a facility name, address, a sales floor area, the number of vehicles to be parked, business hour, and the like.  
         [0056]      FIG. 4  is an illustration showing the case where the on-vehicle navigation apparatus  100  does not perform map matching during retrieval of facilities around a current position, and there is no navigation route being guided, and a facility retrieval range set when facility retrieval is not performed in the vicinity of the current position. In this example, a circle of a predetermined distance from a current position (specified position) (a circular area having a predetermined radius with the current position at center) is set as a facility retrieval range. The predetermined radius can be changed by the user by performing operations on the operation switch group  7  and the like.  
         [0057]      FIG. 5  is an illustration showing a facility retrieval range set in the case where the on-vehicle navigation apparatus  100  performs map matching during retrieval of facilities around a current position, and there is no navigation route being guided. In this example, a predetermined distance area to an advancing direction from a current position (direction to a destination) is set as a facility retrieval range. The predetermined distance can be changed by the user by performing operations on the operation switch group  7  and the like.  
         [0058]      FIG. 6  is an illustration showing a facility retrieval range set when there is a navigation route being guided when the on-vehicle navigation apparatus  100  performs facility retrieval in the vicinity of a current position. In this example, a predetermined distance area from the navigation route being guided is set as a facility retrieval range. The predetermined distance can be changed by the user by performing operations on the operation switch group  7  and the like.  
         [0059]      FIG. 7  is an illustration showing a facility retrieval range set by the on-vehicle navigation apparatus  100  when a history route exists or in a similar situation. In this example, for a predetermined distance area from a predetermined distance circle at a current position, a predetermined distance area to an advancing direction, and the navigation route being guided, the predetermined distance area from the history route is set additionally to a facility retrieval range. The predetermined distance can be changed by the user by performing operations on the operation switch group  7  and the like.  
         [0060]      FIG. 8  is a flowchart showing retrieval range setting process in the on-vehicle navigation apparatus  100 .  
         [0061]      FIG. 9  is a flowchart showing sensor data acquisition process in  FIG. 8 .  
         [0062]     The following describes the operation of the on-vehicle navigation apparatus  100  in the first embodiment thus constructed with reference to FIGS.  1  to  9 .  
         [0063]     When the user commands the on-vehicle navigation apparatus  100  to perform retrieval of facilities by uttered words, the control circuit  8  inputs the uttered words through the microphone  15  and the voice recognition unit  14  (voice input/output part  22 ), and the interaction control part  23  determines whether a retrieval request is directly made by a facility name (S 100  of  FIG. 8 ).  
         [0064]     In the case of a direct retrieval request by a facility name (S 100  of  FIG. 8 : YES), the control circuit  8  sets a facility specified by the user in the range of the retrieval by the facility retrieval part  24  (S 114  of  FIG. 8 ), and accesses the map database  28  to perform facility retrieval processing (S 113  of  FIG. 8 ).  
         [0065]     On the other hand, for other than a direct retrieval request by a facility name (S 100  of  FIG. 8 : NO), the control circuit  8  commands the interaction control part  23  to inquire of the user whether to set conditions in the facility retrieval range, through the voice synthesizing circuit  16  and the loudspeaker  17  (voice input/output part  22 ) (S 101  of  FIG. 8 ).  
         [0066]     When the user hears the inquiry uttered from the loudspeaker  17  and sets conditions for the facility retrieval range, the user utters “Set conditions,” and when no conditions are set for the facility retrieval range, the user utters “Set no conditions.” 
         [0067]     The control circuit  8  inputs the uttered words through the microphone  15  and the voice recognition unit  14  (voice input/output part  22 ), and if it is determined by the interaction control part  23  that a reply is made to set no conditions for the facility retrieval range (S 101  of  FIG. 8 : NO), normal navigation operation is performed.  
         [0068]     On the other hand, if it is determined by the interaction control part  23  that a reply is made to set conditions for the facility retrieval range (S 101  of  FIG. 8 : YES), the control circuit  8  inquires of the user whether retrieval is to be performed in the vicinity of a current position, through the voice synthesizing circuit  16  and the loudspeaker  17  (voice input/output part  22 ) (S 102  of  FIG. 8 ).  
         [0069]     When the user hears the inquiry issued from the loudspeaker  17  and performs retrieval in the vicinity of the current position, the user utters “Is there a bookstore around here?.” When the user does not adhere to retrieval in the vicinity of the current position, the user simply utters “I want to go to a bookstore.” 
         [0070]     The control circuit  8  inputs the uttered words through the microphone  15  and the voice recognition unit  14  (voice input/output part  22 ). If it is determined by the interaction control part  23  that a reply is made to perform no retrieval in the vicinity of the current position (S 102  of  FIG. 8 : NO), the facility retrieval part  24 , as shown in  FIG. 4 , sets a predetermined distance circle centered at the current position (specified position) as a facility retrieval range (S 108  of  FIG. 8 ).  
         [0071]     If it is determined that retrieval is to be performed in the vicinity of the current position (S 102  of  FIG. 8 : YES), the control circuit  8  determines whether map matching is performed (S 103  of  FIG. 8 ).  
         [0072]     If it is determined that map matching is being performed (S 103  of  FIG. 8 : YES), the control circuit  8  determines whether there is a navigation route being guided (S 104  of  FIG. 8 ).  
         [0073]     If there is no route being guided (S 104  of  FIG. 8 : NO), the control circuit  8  sets a circular area to an advancing direction by the facility retrieval part  24  as a facility retrieval range, as shown in  FIG. 5  (S 106  of  FIG. 8 ).  
         [0074]     If there is no navigation route being guided (S 104  of  FIG. 8 : YES), the control circuit  8  sets the vicinity of a navigation route being guided as a facility retrieval range by the facility retrieval part  24 , as shown in  FIG. 6  (S 107  of  FIG. 8 ).  
         [0075]     The control circuit  8  refers to the destination history database  26  and the traveling route history database  27  by the history management part  25  to determine whether there is a history route (S 109  of  FIG. 8 ). If there is a history route (S 109  of  FIG. 8 : YES), the interaction control part  23  inquires of the user whether to use the history route, through the voice synthesizing circuit  16  and the loudspeaker  17  (voice input/output part  22 ) (S 110  of  FIG. 8 ). For example, the control circuit  8  inquires of the user, “In addition to the road being currently guided, Route 1 taken before runs nearby. Would you like to include Route 1 in a retrieval range?” 
         [0076]     When the user hears the inquiry issued from the loudspeaker  17  and uses the history route, for example, the user utters, “Include it in a retrieval range.” When the user does not use the history route, the user utters, for example, “Do not include it in a retrieval range.” 
         [0077]     The control circuit  8  inputs the uttered words through the microphone  15  and the voice recognition unit  14  (voice input/output part  22 ), and if it is determined by the history management part  25  that the history route is used (S 110  of  FIG. 8 : YES), as shown in  FIG. 7 , for a predetermined distance area from a predetermined distance circle from a current position, a predetermined distance area to an advancing direction, and the navigation route being guided, the predetermined distance area from the history route is set additionally to a facility retrieval range (S 111  of  FIG. 8 ). In this case, the control circuit  8  responds to the user, for example, with “Bookstores along Route 23 being currently guided and Route 1 will be targeted for retrieval.” 
         [0078]     When there is no history route (S 109  of  FIG. 8 : NO) and the history route is not used (S 110  of  FIG. 8 ; NO), the control circuit  8  skips Step S 111 .  
         [0079]     The control circuit  8  starts sensor information consideration processing (S 112  of  FIG. 8 ).  
         [0080]     In the sensor information consideration processing, the control circuit  8  inquires of the user whether to consider sensor information  29 , by the interaction control part  23  through the voice synthesizing circuit  16  and the loudspeaker  17  (voice input/output part  22 ) (S 201  of  FIG. 9 ).  
         [0081]     When the user hears the inquiry uttered from the loudspeaker  17  and considers sensor information  29 , for example, the user utters, “Consider.” When the user does not consider the sensor information  29 , the user utters, “Do not consider.” 
         [0082]     The control circuit  8  inputs the uttered words through the microphone  15  and the voice recognition unit  14  (voice input/output part  22 ), and when it is determined by the interaction control part  23  that a reply is made not to consider sensor information (S 201  of  FIG. 9 : NO), the sensor information consideration processing is immediately terminated.  
         [0083]     When it is determined that a reply is made to consider sensor information (S 201  of  FIG. 9 : YES), the control circuit  8  acquires date and time information from the sensor information  29  by the facility retrieval part  24  (S 202  of  FIG. 9 ), and inquires of the user whether to consider date and time, through the voice synthesizing circuit  16  and the loudspeaker  17 (voice input/output part  22 ) (S 203  of  FIG. 9 ).  
         [0084]     The user hears the inquiry uttered from the loudspeaker  17  and must consider a day and a time such as a day of the week (weekday or holiday), and a time zone (in the course of going to work or going home in the case of weekday), the user utters, for example, “Necessary,” and when a reply is made not to consider the sensor information, the user utters, for example, “Unnecessary.” 
         [0085]     The control circuit  8  inputs the uttered words through the microphone  15  and the voice recognition unit  14  (voice input/output part  22 ), and if it is determined by the facility retrieval part  24  that a day and time must be considered (S 203  of  FIG. 9 : YES), limits a facility retrieval range according to the day and time information (S 204  of  FIG. 9 ). If a day and a time need not be considered (S 203  of  FIG. 9 : NO), the control circuit  8  skips Step S 204 .  
         [0086]     The control circuit  8  acquires weather information from the sensor information  29  and the like by the facility retrieval part  24  (S 205  of the  FIG. 9 ), and inquires of the user whether to consider weather, by the interaction control part  23  through the voice synthesizing circuit  16  and the loudspeaker  17  (voice input/output part  22 ) (S 206  of  FIG. 9 ).  
         [0087]     When the user hears the inquiry uttered from the loudspeaker  17  and considers weather such as fine, rain, summer, and winter, for example, the user utters, “Necessary.” When a reply is made not to consider weather, the user utters, “Unnecessary.” 
         [0088]     The control circuit  8  inputs the uttered words through the microphone  15  and the voice recognition unit  14  (voice input/output part  22 ), and if it is determined by the interaction control part  23  that a reply is made to consider weather (S 206  of  FIG. 9 : YES), limits a facility retrieval range according to weather information obtained from the sensor information  29  by the facility retrieval part  24  (S 207  of  FIG. 9 ) and terminates the sensor information consideration processing.  
         [0089]     If a reply is made not to consider weather (S 206  of  FIG. 9 : NO), the control circuit  8  skips Step S 207  and terminates the sensor information consideration processing.  
         [0090]     When control returns from the sensor information consideration processing to retrieval range setting processing, the control circuit  8  accesses the map database  28  by the facility retrieval part  24 , and performs facility retrieval processing (S 113  of  FIG. 8 ). In the retrieval processing, since a facility retrieval range is narrowed down in advance, the control circuit  8  can retrieve a facility suitable for user&#39;s situation more rapidly, and retrieval result data  30  is generated. The control circuit  8  outputs, by the interaction control part  23 , retrieval result data  30  to the user through the voice synthesizing circuit  16  and the loudspeaker  17  (voice input/output part  22 ). For example, the control circuit  8  outputs, “There are bookstores A, B, and the like.” to the user. The control circuit  8  displays retrieval result data  30  in the display unit  10  (retrieval result output part  31 ) by the interaction control part  23 .  
         [0091]     According to the first embodiment, since a facility retrieval range can be narrowed down in advance according to the operation situation of the vehicle (map matching state and the existence or absence of a navigation route being guided), sensor information, and history information, a facility suitable for user&#39;s situation can be retrieved more rapidly.  
         [0092]     Although the present disclosure has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art.  
         [0093]     For example, the facility search range may be in a different shape from the one described in the above embodiment. That is, the facility search range may take a rectangular shape, a regular/irregular polygonal shape, a fan shape or the like.  
         [0094]     Further, sensor information such as a atmospheric pressure, brightness, or the like may be considered in combination with other information for search range determination.  
         [0095]     Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.