Voice recognition apparatus, voice recognition method, map displaying apparatus, map displaying method, navigation apparatus, navigation method and car

Voice processing for recognizing a predetermined voice such as a place name is performed by a voice processing section 14 from an audio signal inputted from a microphone 11 on the basis of an operation of a talk switch 18. When a map display is based on the recognized place name is performed, an incorrect reading and a place name commonly mistaken can be also recognized. Accordingly, a high grade operation of a navigation apparatus can be simply performed without obstructing an operator driving while a car.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a voice recognition apparatus and a voice 
recognition method suitably applied to a navigation apparatus mounted to 
e.g., a car and displaying a road map, etc., the navigation apparatus and 
a navigation method combined with this voice recognition apparatus, and a 
car mounting these apparatuses thereon. 
2. Description of the Prior Art 
Various kinds of navigation apparatuses mounted onto a car, etc. have been 
developed. Each of these navigation apparatuses is constructed by a large 
capacity data memory means such as a CD-ROM storing e.g., road map data, a 
detecting means for detecting the present position of the car, and a 
displaying apparatus for displaying a road map in the vicinity of the 
detected present position on the basis of data read from the data memory 
means. In this case, the detecting means of the present position is 
constructed by using a position measuring system using an artificial 
satellite for a position measurement called a GPS (Global Positioning 
System), a self-contained navigation following up a change in the present 
position from a starting spot point on the basis of information such as a 
vehicle's running direction, a vehicle's running speed, etc. 
A map displayed in the displaying apparatus is set such that a map in a 
desirable position can be displayed as well as the present position by 
performing a key operation, etc. as long as map data are prepared. 
In the case of such a navigation apparatus, for example, in the case of the 
navigation apparatus for a car, the displaying apparatus is generally 
arranged in the vicinity of a driver seat such that a driver can see a map 
in the vicinity of the present position while the car is running and 
temporarily stops as in traffic signal stoppage, etc. 
It is necessary to be able to operate such a navigation apparatus such that 
no navigation apparatus obstructs driving of the car, etc. For example, 
the navigation apparatus is constructed such that a complicated operation 
of the navigation apparatus is inhibited during the car driving. Namely, 
when such a navigation apparatus is arranged in a vehicle, the navigation 
apparatus is connected to a certain running state detecting section (e.g., 
a parking brake switch of the car). The navigation apparatus is set such 
that all operations of the navigation apparatus can be performed only when 
stoppage of the vehicle is detected by this running state detecting 
section, and a complicated key operation is inhibited in a nonstopping 
state (namely, during running of the vehicle). 
However, it is inconvenient that no operation for switching display maps, 
etc. can be performed during such running. Accordingly, it is required 
that a high grade operation of the navigation apparatus can be performed 
without obstructing the driving of the vehicle even when the vehicle is 
running. 
SUMMARY OF THE INVENTION 
In consideration of such problem points, an object of the present invention 
is to be able to simply perform high grade operations of various kinds of 
apparatuses such as a navigation apparatus, etc. without obstructing the 
driving of a car, etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
One embodiment of the present invention will next be described with 
reference to the accompanying drawings. 
In this example, the present invention is applied to a navigation apparatus 
mounted to a car. An arranging state of the navigation apparatus mounted 
to the car in this example will first be explained with reference to FIGS. 
1 and 2. As shown in FIG. 1, a handle 51 of the car 50 is attached to a 
front portion of a driver seat 52 and a driver sitting on the driver seat 
52 basically operates the navigation apparatus. However, there is also a 
case in which another fellow passenger within this car 50 operates the 
navigation apparatus. A body 20 of this navigation apparatus and a voice 
recognition apparatus 10 connected to this navigation apparatus body 20 
are arranged in an arbitrary space (e.g., within a trunk of a rear 
portion) within the car 50. An antenna 21 for receiving a position 
measuring signal described later is attached onto the outer side of a car 
body (otherwise, within the car such as the inner side of a rear window, 
etc.). 
As shown in the vicinity of the driver seat in FIG. 2, a talk switch 18 and 
an operation key 27 of the navigation apparatus described later are 
arranged on a side of the handle 51 such that the talk switch 18 and the 
operation key 27 are operated without causing any obstruction during 
driving of the car. A displaying apparatus 40 connected to the navigation 
apparatus is also arranged in a position in which no field of view in 
front of the driver is obstructed. A speaker 32 for outputting an audio 
signal synthesized as a voice within the navigation apparatus 20 is 
attached to the car in a position in which an output voice reaches the 
driver (e.g., on a side of the displaying apparatus 40, etc.). 
A voice can be inputted to the navigation apparatus in this example. 
Therefore, a microphone 11 is attached to a sun visor 53 arranged in an 
upper portion of a front glass in front of the driver seat 52 so that the 
microphone 11 collects a speaking voice of the driver sitting on the 
driver seat 52. 
The navigation apparatus body 20 in this example is connected to a computer 
54 for controlling the operation of an engine of this car so that a pulse 
signal proportional to a car speed is supplied from this computer 54 to 
the navigation apparatus body 20. 
An internal construction of the navigation apparatus in this example will 
next be explained with reference to FIG. 3. In this example, the voice 
recognition apparatus 10 is connected to the navigation apparatus 20 and 
the microphone 11 is connected to the voice recognition apparatus 10. For 
example, directivity of this microphone 11 is set to be relatively narrow 
and the microphone 11 is constructed such that only a speaking voice of a 
person sitting on the driver seat of the car is preferably collected. 
An audio signal collected by this microphone 11 is supplied to an 
analog/digital converter 12 and is sampled by a signal of a predetermined 
sampling frequency and is converted to a digital audio signal. Then, the 
digital audio signal outputted from this analog/digital converter 12 is 
supplied to a digital voice processing circuit 13 constructed by an 
integrated circuit called a DSP (digital signal processor). In this 
digital voice processing circuit 13, the digital voice signal is set to 
vector data by processings such as band division, filtering, etc., and 
these vector data are supplied to a voice recognition circuit 14. 
A ROM 15 for storing voice recognition data is connected to this voice 
recognition circuit 14 so that a recognizing operation is performed in 
accordance with a predetermined voice recognizing algorithm (e.g., HMM: 
Hidden Markov model) with respect to the vector data supplied from the 
digital voice processing circuit 13. This ROM 15 then selects plural 
candidates from phonemic models for voice recognition stored to the ROM 15 
and reads character data stored in accordance with a phonemic model having 
a highest conformity degree among these candidates. 
Here, a data storing state of the ROM 15 for storing the voice recognizing 
data in this example will be explained. In the case of this example, only 
the name of a place and a word for designating an operation of the 
navigation apparatus are recognized. As shown in a setting state of a 
memory area in FIG. 4, only the names of domestic urban and rural 
prefectures, cities, wards, towns and villages are registered as the name 
of a place. A character code of this place name and a phonemic model as 
data for recognizing the place name as a voice are stored to the memory 
area for each of the urban and rural prefectures, cities, wards, towns and 
villages. 
For example, in the case of the interior of the country of Japan, the 
number of cities, wards, towns and villages in the whole country is about 
3500 so that about 3500 place names are stored to the memory area. 
However, in the case of the place name of "xx town", both data showing the 
pronouncing case of "xx machi" and data showing the pronouncing case of 
"xx cho" are stored. Similarly, in the case of the place name of "xx 
village", both data showing the pronouncing case of "xx son" and data 
showing the pronouncing case of "xx mura" are stored. 
The names of urban and rural prefectures tending to be mistaken are 
additionally registered with respect to the names of cities, wards, towns 
and villages having a high possibility that the names of urban and rural 
prefectures are incorrectly remembered such as cities, wards, towns and 
villages, etc. adjacent to boundaries of the urban and rural prefectures 
in position. Namely, for example, "Kawasaki city, Kanagawa prefecture" is 
registered and "Kawasaki city, Tokyo Metropolis" providing an adjacent 
name of each of the urban and rural prefectures is also registered. 
Character codes of words for giving commands of various kinds of operations 
such as words designating display positions such as "destination", 
"starting spot", "routing spot", "one's own house", etc., "what time now" 
(a command for hearing the present time), "where now" (a command for 
hearing the present position), "next" (a command for hearing the next 
intersection), "how far from here" (a command for hearing a distance until 
the destination), "speed" (a command for hearing the present speed), 
"altitude" (a command for hearing the present altitude), "advancing 
direction" (a command for hearing an advancing direction), "list" (a 
command for displaying a list of recognizable commands in the displaying 
apparatus), etc., and others are stored as words for designating the 
operation of the navigation apparatus. Further, a phonemic model 
corresponding to each of these words is also stored. With respect to the 
command for hearing the present time, character codes and phonemic models 
corresponding to other words such as "present time", "time", etc., in 
addition to "what time now" mentioned above are stored. The present time 
command is responded even when the command is given by any voice. 
When a character code corresponding to a phonemic model and conforming to 
recognized results obtained through a predetermined voice recognizing 
algorithm from input vector data is the character code of a place name in 
the voice recognition circuit 14, this character code is read from the ROM 
15. This read character code is supplied to a converting circuit 16. A ROM 
17 for storing converted data is connected to this converting circuit 16. 
Longitude and latitude data corresponding to the character data supplied 
from the voice recognition circuit 14 and their accompanying data are read 
from the ROM 17. 
Here, a data storing state of the ROM 17 for storing converted data in this 
example will be explained. In the case of this example, a memory area is 
set for every character code of the same pronunciation as the character 
code of a place name stored to the ROM 15 for storing voice recognizing 
data. As shown in FIG. 5, an apparatus operation in a recognizing case of 
this word, the character code of a responsive voice, longitude and 
latitude data of a region in a case in which the voice shows a place name 
of this region, and data displayed as characters (a character code using 
Chinese characters, etc.) are stored for every character code. 
In the case of this example, as mentioned above, in the case of the names 
of towns and villages, voices can be recognized in both the pronouncing 
cases of "xx machi" and "xx mura" and the pronouncing cases of "xx cho" 
and "xx son". However, as shown in FIG. 5, a responsive voice stored to 
the ROM 17 is set to data for outputting the voice of a correct 
pronunciation with respect to any recognized voice. 
When the names of urban and rural prefectures tending to be mistaken is 
provided and registered with respect to the names of cities, wards, towns 
and villages having a high probability that the names of urban and rural 
prefectures are incorrectly remembered such as cities, wards, towns and 
villages, etc. located on boundaries of the urban and rural prefectures, 
the responsive voice stored to the ROM 17 is set to data for outputting 
the voice of a correct pronunciation of each of the names of the urban and 
rural prefectures with respect to any recognized voice and is also set to 
data for displaying a correct name of each of the urban and rural 
prefectures as display data. For example, as shown in FIG. 5, "Kawasaki 
city, Kanagawa prefecture" is set and stored as data stored to a column of 
the responsive voice even when "Kawasaki city, Tokyo Metropolis" is 
registered as an incorrect example of a recognizable voice. Further, data 
stored to the column of display data are set such that "Kawasaki city, 
Kanagawa prefecture" is displayed. 
FIG. 5A further shows an application example of the present invention. This 
example shows a case in which "Kawasaki city, Kanagawa prefecture" is 
pronounced in Japanese, and a case in which "Kawasaki, Kanagawa" is 
pronounced in English. In these cases, separate character codes are 
respectively outputted in Japanese and English, but common longitude and 
latitude data are outputted. 
In the case of this example, the latitude and longitude data for every 
place name are set to latitude and longitude data showing an absolute 
position of the seat of a government office (a city office, a ward office, 
a town office, a village office) in a region shown by its place name. 
The longitude and latitude data and the character code data read from the 
ROM 17 for storing longitude and latitude converting data are supplied to 
output terminals 10a and 10b as outputs of the voice recognition apparatus 
10. The obtained data of these output terminals 10a and 10b are supplied 
to the navigation apparatus 20. A talk switch 18 is arranged as an 
unlocked open-close switch (namely, a switch attaining a turning-on state 
only when the switch is pushed) in the voice recognition apparatus 10 in 
this example. While this talk switch 18 is pushed, the above processing is 
performed with respect to only an audio signal collected by the microphone 
11 by circuits from the analog/digital converter 12 to a longitude 
latitude converting circuit 16. 
The construction of the navigation apparatus 20 connected to the voice 
recognition apparatus 10 will next be explained. This navigation apparatus 
20 has an antenna 21 for a GPS. A signal for a position measurement from a 
satellite for the GPS received by this antenna 21 is received and 
processed by a present position detecting circuit 22. The present position 
of the navigation apparatus is detected by analyzing the received data. 
Data of the detected present position are latitude and longitude data in 
an absolute position at this time. 
The data of the detected present position are supplied to an arithmetic 
circuit 23. This arithmetic circuit 23 functions as a system controller 
for controlling the operation of the navigation apparatus 20. The 
arithmetic circuit 23 is connected to a CD-ROM driver 24, a RAM 25, a car 
speed sensor 26 and an operation key 27. In the CD-ROM driver 24, a CD-ROM 
(an optical disk) storing road map data thereto is set and the CD-ROM 
driver 24 reads stored data of this CD-ROM. The RAM 25 stores various 
kinds of data required for data processing. The car speed sensor 26 
detects the movement of a vehicle mounting this navigation apparatus 
thereon. When longitude and latitude coordinate data in the present 
position, etc. are obtained, the arithmetic circuit 23 controls a reading 
operation for reading the road map data in the vicinity of its coordinate 
position to the CD-ROM driver 24. The arithmetic circuit 23 then makes the 
RAM 25 temporarily store the road map data read by the CD-ROM driver 24 
and makes display data for displaying a road map by using these stored 
road map data. At this time, these display data are set to display data 
for displaying the map by a display scale (a reduced scale) set by an 
operation of the operation key 27 arranged in a predetermined position 
within the car, etc. 
The display data made by the arithmetic circuit 23 are then supplied to a 
video signal generating circuit 28. A video signal of a predetermined 
format is generated by this video signal generating circuit 28 on the 
basis of the display data. This video signal is supplied to an output 
terminal 20c. 
The video signal outputted from this output terminal 20c is then supplied 
to a displaying apparatus 40 and image receiving processing based on the 
video signal is performed by this displaying apparatus 40. Thus, the road 
map, etc. are displayed on a display panel of the displaying apparatus 40. 
In addition to the display of such a road map in the vicinity of the 
present position, a road map, etc. in a position designated by the 
operation of the operation key 27, etc. can be set to be displayed on the 
basis of the control of the arithmetic circuit 23. Further, a specific 
coordinate position such as "destination", "starting spot", "routing 
spot", "one's own house", etc. can be set to be registered on the basis of 
the operation of the operation key 27, etc. When this specific coordinate 
position is registered, data (longitude and latitude data) in this 
registered coordinate position are stored to the RAM 25. 
When the car speed sensor 26 detects running of the car, the arithmetic 
circuit 23 is set such that no operation except for a relatively simple 
operation within the operation of the operation key 27 is received. 
This navigation apparatus 20 also has a self-contained navigation section 
29. The navigation apparatus 20 calculates an exact running speed of the 
car on the basis of a pulse signal corresponding to a car speed and 
supplied to the computer for engine control, etc. on a car side. The 
navigation apparatus 20 also detects an advancing direction of the car on 
the basis of an output of a gyro sensor arranged within the self-contained 
navigation section 29. The navigation apparatus 20 then measures the 
present position of the car by the self-contained navigation from a 
position determined on the basis of the car speed and the advancing 
direction. For example, when the present position detecting circuit 22 
attains a state unable to detect the car position, the car position is 
measured by the self-contained navigation from a car position finally 
detected by the present position detecting circuit 22. 
A voice synthetic circuit 31 is also connected to the arithmetic circuit 
23. When any designation using a voice is required in the arithmetic 
circuit 23, the voice synthetic circuit 31 executes synthetic processing 
of this designated voice and a voice is set to be outputted from the 
speaker 32 connected to the voice synthetic circuit 31. For example, 
various kinds of designations required for the navigation apparatus such 
as "Car approaches destination", "Advancing direction is left", etc. are 
given through voices. Further, in this voice synthetic circuit 31, a voice 
recognized by the voice recognition apparatus 10 is set to be synthesized 
on the basis of supplied character data and be outputted as a voice from 
the speaker 32. This voice synthetic processing will be described later. 
Here, this navigation apparatus 20 has input terminals 20a and 20b. The 
longitude and latitude data and the data of a character code outputted 
from the output terminals 10a and 10b of the voice recognition apparatus 
10 are supplied to the input terminals 20a and 20b. The longitude and 
latitude data and the character code data obtained at these input 
terminals 20a and 20b are supplied to the arithmetic circuit 23. 
When these longitude and latitude data, etc. are supplied from the voice 
recognition apparatus 10, the arithmetic circuit 23 performs a reading 
control operation for reading road map data in the vicinity of the 
longitude and latitude from a disk by the CD-ROM driver 24. Then, the 
arithmetic circuit 23 makes the CD-ROM driver 24 temporarily store the 
read road map data to the RAM 25 and makes display data for displaying a 
road map by using these stored road map data. At this time, the display 
data are set to data displayed with the supplied longitude and latitude as 
a center. 
A video signal is generated by the video signal generating circuit 28 on 
the basis of these display data. The displaying apparatus 40 displays a 
road map in a coordinate position designated from the voice recognition 
apparatus 10. When the road map in the coordinate position designated from 
this voice recognition apparatus 10 is displayed, the video signal for 
displaying the road map is set to a video signal for displaying a 
recognized place name by characters at a corner of the screen, etc. when 
the video signal for displaying the road map is generated by the video 
signal generating circuit 28. This display of the place name is erased 
when a predetermined time has passed (e.g., several tens of seconds have 
passed) since the place name was displayed (namely, since the video signal 
was outputted). 
When the character code of a word for designating the operation of the 
navigation apparatus is supplied from the output terminal 10b of the voice 
recognition apparatus 10 and is discriminated by the arithmetic circuit 
23, the arithmetic circuit 23 performs corresponding control. In this 
case, when this character code is the character code of a word for 
designating a display position such as "destination", "starting spot", 
"routing spot", "one's own house", etc., it is judged whether a coordinate 
in this display position is registered to the RAM 25 or not. Thereafter, 
when this coordinate is registered to the RAM 25, the CD-ROM driver 24 
performs a reading control operation for reading road map data in the 
vicinity of this display position from a disk. 
When data of a character code showing the pronunciation of a recognized 
voice are supplied from the voice recognition apparatus 10 to the 
arithmetic circuit 23, a word shown by this character code is 
synthetically processed by the voice synthetic circuit 31 and is outputted 
as a voice from the speaker 32 connected to the voice synthetic circuit 
31. For example, when "Bunkyo ward, Tokyo Metropolis" is recognized as a 
voice on a side of the voice recognition apparatus 10, the voice synthetic 
circuit 31 performs synthetic processing for generating an audio signal 
for pronouncing "Bunkyo ward, Tokyo Metropolis" on the basis of data of a 
character series of this recognized pronunciation. This generated audio 
signal is outputted from the speaker 32. 
In this case, when the voice is recognized by the voice recognition 
apparatus 10 in this example, longitude and latitude data are supplied to 
the terminal 20a of the navigation apparatus 20 approximately 
simultaneously when the data of a character code showing the pronunciation 
of the recognized voice are supplied to the terminal 20b. The arithmetic 
circuit 23 first executes processing for synthesizing a word recognized by 
the voice synthetic circuit 31 as a voice, and next executes processing 
for making the display data of a road map based on the longitude and 
latitude data. 
An operation of the voice recognition apparatus, etc. will next be 
explained when a road map display, etc. are performed by using the voice 
recognition apparatus 10 and the navigation apparatus 20 in this example. 
The flow chart of FIG. 6 shows a voice recognizing operation performed by 
the voice recognition apparatus 10. In a step 101, it is first judged 
whether the talk switch 18 is turned on or not. When it is judged that 
this talk switch 18 is turned on, an audio signal collected by the 
microphone 11 for a period of this turning-on operation is sampled by the 
analog/digital converter 12 and is processed by the digital voice 
processing circuit 13 and is changed to vector data (step 102). Then, the 
voice recognition circuit 14 performs voice recognizing processing based 
on these vector data (step 103). 
Here, it is judged in a step 104 whether the voice of a place name (namely, 
a place name registered in advance) stored to the ROM 15 for storing voice 
recognition data is recognized or not. When the voice of the registered 
place name is recognized, character data for pronouncing the recognized 
place name are read from the ROM 15 and are outputted from the output 
terminal 10b (step 105). Further, longitude and latitude data of the 
recognized place name are read from the ROM 17 for storing longitude and 
latitude converting data connected to the longitude latitude converting 
circuit 16 (step 106). Here, in the voice recognition of the place name, 
place names registered to the ROM 15 in this example are constructed by 
the names of domestic urban and rural prefectures, cities, wards, towns 
and villages. Accordingly, for example, a voice of "xx city, xx 
prefecture" and a voice of "xx ward, xx city" (here, the voice can be set 
to be recognized even when the names of urban and rural prefectures are 
omitted in the ward case) are recognized. 
The longitude and latitude data read on the basis of the recognized voice 
and accompanying data thereof are outputted from the output terminal 10a 
(step 107). 
When no voice of the registered place name can be recognized in the step 
104, it is judged in a step 108 whether a specific registered voice except 
for the place name is recognized or not. Here, when the specific 
registered voice except for the place name is recognized, a character code 
corresponding to the recognized voice is judged (step 109) and is 
outputted from the output terminal 10b (step 110). 
In contrast to this, when no specific registered voice except for the place 
name can be recognized in the step 108, processing at this time is 
terminated. Otherwise, disability of the voice recognition is transmitted 
to the navigation apparatus 20. The navigation apparatus 20 then gives 
warning by a synthetic voice in the voice synthetic circuit 31 or 
characters, etc. displayed in the displaying apparatus 40. 
Next, the flow chart of FIG. 7 shows the operation of the navigation 
apparatus 20. It is first judged in the arithmetic circuit 23 in a step 
201 whether a display mode in the present position is set or not. When it 
is judged that the display mode in the present position is set, the 
present position detecting circuit 22 measures the present position (step 
202). Road map data in the vicinity of the measured present position are 
read from the CD-ROM (step 203). Display processing of a road map based on 
these read road map data is performed and the road map in a corresponding 
coordinate position is displayed in the displaying apparatus 40 (step 
204). 
In contrast to this, when it is judged in the step 201 that no display mode 
in the present position is set, or, when the display processing of the 
road map in the present position in the step 204 is terminated and a 
displaying state of this road map is set, it is judged in a step 205 
whether longitude and latitude data, etc. are supplied from the voice 
recognition apparatus 10 through the input terminals 20a and 20b. Here, 
when it is judged that the longitude and latitude data and accompanying 
character data thereof, etc. are supplied, a character code for a 
pronunciation supplied through the terminal 20b is first supplied to the 
voice synthetic circuit 31 and a voice recognized by the voice recognition 
apparatus 10 is synthesized and outputted from the speaker 32 (step 206). 
Subsequently, road map data in the vicinity of a position shown by the 
longitude and latitude data are read from the CD-ROM (step 207) and 
display processing of a road map based on these read road map data is 
performed. The road map in a corresponding coordinate position is then 
displayed in the displaying apparatus 40 (step 208). 
When it is judged in the step 205 that no longitude and latitude data are 
supplied from the voice recognition apparatus 10, or when display 
processing of the road map of a designated place name in the step 208 is 
terminated and a displaying state of this road map is set, it is judged in 
a step 209 whether or not a character code for directly designating a 
display position is supplied from the voice recognition apparatus 10 
through the input terminal 20b. When it is judged that the character code 
is supplied from the terminal 20b, this character code is supplied to the 
voice synthetic circuit 31 and a voice recognized by the voice recognition 
apparatus 10 is outputted from the speaker 32 (step 210). Next, when the 
character code (namely, words of "destination", "starting spot", "routing 
spot", "one's own house", etc.) for directly designating the display 
position is discriminated in the step 209, it is judged in a step 211 
whether a coordinate position designated by these characters is registered 
to the RAM 25 or not. When this coordinate position is registered to the 
RAM 25, road map data in the vicinity of a position shown by the longitude 
and latitude data as the registered coordinate position are read from the 
CD-ROM (step 212). Then, display processing of a road map based on these 
read road map data is performed and a road map in the corresponding 
coordinate position is displayed in the displaying apparatus 40 (step 213) 
and it is returned to the step 201 in this displaying state. 
When it is judged in the step 209 that no character code for directly 
designating the display position is supplied from the voice recognition 
apparatus 10, it is judged in the arithmetic circuit 23 in a step 214 
whether or not there is an operation for designating the display position 
by operating the operation key 27. When there is an operation for 
designating this display position, it is judged in a step 215 from 
detected data of the car speed sensor 26 whether the vehicle is running at 
the present time or not. When the arithmetic circuit 23 judges that the 
vehicle is running, the operation at this time is invalidated and it is 
returned to the step 201 (a certain warning may be given at this time). 
When it is judged that no vehicle is running, control goes from step 211. 
In the step 211, it is judged whether there is a registered coordinate or 
not. Thereafter, when there is a registered coordinate position, display 
processing of a road map in this position is performed in the steps 212, 
213 and it is then returned to the step 201. 
In contrast to this, when no coordinate in a corresponding position such as 
"destination", "starting spot", "routing spot", "one's own house", etc. is 
registered in the step 211, an unregister warning is given by a synthetic 
voice in the voice synthetic circuit 31 or display characters in the 
displaying apparatus 40 in a step 216 and it is then returned to the step 
201. 
Processing relative to the map display is explained with reference to the 
flow chart of FIG. 7. However, when a character code is supplied from the 
voice recognition apparatus 10 as a result of the recognition of a voice 
for designating an operation except for the map display, corresponding 
processing is performed on the basis of control of the arithmetic circuit 
23. For example, when "what time now", etc. are recognized and a character 
code is supplied, a voice for pronouncing the present time is synthesized 
by the voice synthetic circuit 31 on the basis of the control of the 
arithmetic circuit 23 and is outputted from the speaker 32. The other 
commands are also processed such that a responsive voice is synthesized by 
the voice synthetic circuit 31 and is outputted from the speaker 32, or a 
corresponding display is performed by the displaying apparatus 40. 
Here, FIG. 8 shows processings in summary until a map is displayed on the 
basis of the voice recognition among the operations of the voice 
recognition apparatus 10 and the navigation apparatus 20 explained above. 
It is first judged in a step 301 whether the talk switch 18 is turned on or 
not. When the talk switch 18 is turned on, a reading operation of an audio 
signal from the microphone 11 is started. The read audio signal is changed 
to digital data and is stored to a memory within the digital voice 
processing circuit 13 (step 302). The stored voice data are converted to 
vector data at any time and are recognized as a voice by the voice 
recognition circuit 14 (step 303). It is then judged in a step 304 whether 
the talk switch 18 is turned off or not. The voice recognizing processing 
is continuously performed until the talk switch 18 is turned off. 
When the talk switch 18 is turned off, the reading operation of the audio 
signal from the microphone 11 is terminated in a step 305. The voice 
recognition processing with respect to the voice data read at this time 
point is continuously performed in a step 306. When it is judged in a step 
307 that the voice recognizing processing is terminated, the character 
code of a voice as a recognized result is supplied to the navigation 
apparatus 20 and the voice as a recognized result is synthetically 
processed in the voice synthetic circuit 31 and is outputted from the 
speaker 32 in a step 308. When the recognized voice is a place name, road 
map data in the vicinity of a position shown by longitude and latitude 
data are read from the CD-ROM on the basis of data in a coordinate 
position of this place name. A video signal for displaying a road map 
based on these read road map data is generated in the video signal 
generating circuit 28. Thus, the road map in the vicinity of the 
corresponding coordinate position is displayed in the displaying apparatus 
40 in a step 309. 
A slight time (e.g., about 2 to 3 seconds) is required from the detection 
of the turning-off of the talk switch in the step 304 until the voice 
recognizing processing is terminated and the recognized result is 
outputted as a voice in the step 308. Further, a time of several seconds 
is required until a map in the corresponding position is displayed in the 
displaying apparatus 40 in the step 309. 
Since the above display processing is performed, the display position can 
be freely set by a voice input in any place in the whole country and a 
road map in a desirable position can be simply displayed. Namely, the 
voice of an operator is simply recognized when the operator speaks "xx 
city, xx prefecture" and "xx ward, xx city" toward the microphone 11 while 
the operator pushes the talk switch 18. A road map in this region is also 
displayed. Accordingly, it is not necessary to designate a position by a 
key operation, etc. For example, the navigation apparatus can be operated 
even in a situation in which it is difficult to perform the key operation. 
In this case, the voice of a place name recognized by the voice 
recognition apparatus 10 in this example is limited to the names of 
domestic urban and rural prefectures, cities, wards, towns and villages so 
that the number of recognized voices is limited to a relatively small 
number (about 3500). Accordingly, the place name can be recognized by the 
voice recognition processing for a short time by a relatively small 
processing amount by the voice recognition circuit 14 within the voice 
recognition apparatus 10. Therefore, it is possible to shorten a time 
until a map designated in an inputted voice is displayed. Further, a 
recognition rate itself is also improved since the number of recognized 
place names is limited. 
In this example, when the names of cities, wards, towns and villages are 
recognized as voices by the voice recognition apparatus 10, it is 
recognized as the same place name in both the pronouncing cases of "machi" 
and "son" and the pronouncing cases of "cho" and "mura" with respect to 
"town" and village". Accordingly, the place name itself can be correctly 
recognized even when the pronunciations of "town" and "village" are 
incorrect, thereby improving the recognition rate correspondingly. 
Further, the names of cities, wards, towns and villages tending to be 
mistaken with respect to the names of urban and rural prefectures can be 
also recognized correctly even when these names of the urban and rural 
prefectures are mistaken, thereby further improving the recognition rate. 
When such a pronunciation is different from a correct pronunciation and an 
incorrect place name is recognized and its recognized result is outputted 
as a voice by the voice synthesis in the voice synthetic circuit 31, a 
correct voice read from the ROM 17 is outputted from the speaker 32 so 
that an operator knows the correct pronunciation and place name. 
In the case of a word for designating the operation of the navigation 
apparatus, e.g., in the case of commands for hearing the present time, 
voices of commands for substantially hearing the same contents such as 
"present time", "time", etc. in addition to "what time now" are prepared 
as plural kinds of recognizable words. Accordingly, it is sufficient to 
designate the operation by a word used most easily for a user of the 
navigation apparatus. Therefore, the operation can be simply designated. 
In the case of this example, data of a coordinate position corresponding to 
the place name stored to the ROM 17 within the voice recognition apparatus 
10 are set to latitude and longitude data showing an absolute position in 
the seat of a government office (a city office, a ward office, a town 
office, a village office) in its region. Accordingly, a map with the 
government office as a center in its region is displayed so that a 
preferable display state is set. Namely, the government office in each 
region is located in a central portion of this region relatively in many 
cases. Accordingly, the possibility of a most preferable display form is 
high. 
In the case of this example, a voice ("destination", "starting spot", 
"routing spot", "one's own house", etc.) for specifying a place except for 
the place name can be also recognized by the voice recognition apparatus 
10. Accordingly, a display position can be directly set to a registered 
position by performing this designation through a voice. In this case, it 
is not necessary to judge coordinate data within the voice recognition 
apparatus 10 so that processing of the voice recognition apparatus 10 can 
be correspondingly performed rapidly. 
In the above embodiment, place names recognized by the voice recognition 
apparatus are limited to the names of domestic urban and rural 
prefectures, cities, wards, towns and villages. However, more detailed 
place names may be recognized. In this case, when the number of 
recognizable place names is increased, a processing amount and a 
processing time required for the voice recognition are correspondingly 
increased. Therefore, it is most preferable to limit the number of 
recognizable place names to about the number of names of cities, wards, 
towns and villages so as to improve the recognition rate. 
In the above embodiment, a central coordinate for every place name is set 
to latitude and longitude data showing an absolute position in the seat of 
a government office (a city office, a ward office, a town office, a 
village office) in its region, but may be set to latitude and longitude 
data showing another position. For example, the central coordinate may be 
simply set to latitude and longitude data of a center of its region (a 
city, a ward, a town, a village). 
Further, data in the coordinate positions of end portions of east, west, 
south and north in its region may be stored instead of such central 
latitude and longitude data. In this case, it is sufficient if there are 
four sets of data of east and west longitudes and south and north 
latitudes. 
In the above embodiment, a recognized voice is converted to a character 
code by the voice recognition apparatus 14 within the voice recognition 
apparatus, and this character code is converted to longitude and latitude 
data by the longitude latitude converting circuit 16. However, the 
recognized voice may be directly converted to longitude and latitude data. 
When no recognized voice is directly converted to the longitude and 
latitude data, the ROM 15 and the ROM 17 for storing these converted data 
may be constructed by the same memory such that, for example, the memory 
area of a place name is commonly used. 
In the above embodiment, the present invention is applied to a navigation 
apparatus using a position measuring system called a GPS. However, the 
present invention can be also applied to a navigation apparatus using 
another position measuring system. 
In accordance with the voice recognition apparatus of the present 
invention, it is possible to cope with a case in which there are plural 
voices with respect to the same control state in accordance with a 
difference in reading, etc. Accordingly, the possibility of correctly 
performing processing based on the voice recognition is increased. 
In this case, when a voice with respect to a place name is recognized, a 
voice processing section can recognize both a voice provided in a correct 
reading way of this place name and a voice provided in an incorrect 
reading way. Accordingly, the correct voice can be recognized even when 
the voice is recognized in the incorrect reading way of the place name. 
When the voice with respect to the place name is recognized in the voice 
processing section, it is possible to recognize both the correct voice of 
this place name and a voice having a mistaken possibility in reading. 
Accordingly, the mistaken place name (a place name not corresponding to an 
existing location) is also recognized and processing for coping with such 
a case can be performed. 
Further, when a voice with respect to operating commands is recognized by 
the voice processing section, the same control data are outputted from a 
data output section by voice recognition of the operating commands 
substantially having the same contents. Accordingly, the operating 
commands can be given in voices in various speaking ways. 
In the voice recognition method of the present invention, it is possible to 
cope with a case in which there are plural voices with respect to the same 
control state in accordance with a difference in reading, etc. 
Accordingly, the possibility of correctly performing processing based on 
the voice recognition is increased. 
In the navigation apparatus of the present invention, it is possible to 
cope with a case in which there are plural voices with respect to the same 
control state in accordance with a difference in reading, etc. 
Accordingly, the possibility of correctly performing processing of a map 
display, etc. based on the voice recognition is increased. 
In this case, when a voice with respect to a place name is recognized by 
the voice processing section, the voice processing section can recognize 
both a voice provided in a correct reading way of this place name and a 
voice provided in an incorrect reading way. Accordingly, the correct voice 
can be recognized even when the voice is recognized in the incorrect 
reading way of the place name. 
When the voice with respect to the place name is recognized in the voice 
processing section, it is possible to recognize both the correct voice of 
this place name and a voice having a mistaken possibility in reading. 
Accordingly, the mistaken place name (a place name not corresponding to an 
existing location) is also recognized and processing for coping with such 
a case can be performed. 
Further, when a voice with respect to operating commands is recognized by 
the voice processing section, the same control data are outputted from a 
data output section by voice recognition of the operating commands 
substantially having the same contents. Accordingly, the operating 
commands can be given in voices in various speaking ways. 
In the navigation method of the present invention, it is possible to cope 
with a case in which there are plural voices with respect to the same 
control state in accordance with a difference in reading, etc. 
Accordingly, the possibility of correctly performing processing such as a 
map display, etc. based on the voice recognition is increased. 
In the car of the present invention, when there are plural voices with 
respect to the same control state in accordance with a difference in 
reading, etc., designated processing is performed even when any voice is 
recognized. 
Having described a preferred embodiments of the invention with reference to 
the accompanying drawings, it is to be understood that the invention is 
not limited to those precise embodiments and that various changed and 
modifications could be effected threin by one skilled in the art without 
departing from the spirit or scope of the invention as defined in the 
appended claims.