Artificial intelligence apparatus and method for recognizing speech of user in consideration of word usage frequency

1. An artificial intelligence apparatus for recognizing speech of a user, comprising:

a microphone; and

a processor configured to:

obtain, via the microphone, speech data including speech of a user,

for each of a plurality of sections of the speech data:

calculate a probability for each of a plurality of words,

determine, using a speech recognition log, a frequency weight for each of the plurality of words,

for each of the plurality of words, calibrate the probability by multiplying the calculated probability by the determined frequency weight,

convert the speech data into text by (i) selecting, for each section of the plurality of sections, a word having a highest calibrated probability and (ii) combining the selected words, and

perform control based on the text.

2. The artificial intelligence apparatus of claim 1 , wherein the processor is configured to:

normalize the calibrated probabilities, and

convert the speech data into the text by selecting, for each section of the plurality of sections, a word having a highest normalized calibrated probability.

3. The artificial intelligence apparatus of claim 1 , wherein the processor is configured to:

check a usage frequency of a word using the speech recognition log, and

set, based on usage frequencies of words, a frequency weight of a word to be higher than a frequency weight of another word.

4. The artificial intelligence apparatus of claim 3 , wherein the processor is configured to:

determine a private frequency weight for a word using a private speech recognition log,

determine a public frequency weight for a word using a public speech recognition log, and

calibrate a probability for a word using the private frequency weight and the public frequency weight,

wherein the private speech recognition log includes speech recognition logs in the artificial intelligence apparatus, and

wherein the public speech recognition log includes speech recognition logs in an external apparatus.

5. The artificial intelligence apparatus of claim 4 , wherein the processor is configured to:

determine an integrated frequency weight by calculating a weighted sum of a private frequency weight of a word and a public frequency weight of a word, and

calibrate a probability using the integrated frequency weight.

6. The artificial intelligence apparatus of claim 1 , wherein the processor is configured to:

determine utterance situation information corresponding to an utterance situation, and

calibrate a frequency weight for a word using the utterance situation information.

7. The artificial intelligence apparatus of claim 6 ,

wherein the utterance situation information includes at least one of a type of the artificial intelligence apparatus, an installation location of the artificial intelligence apparatus, a location of the user, a main user, and a device operation status, and

wherein the device operation status includes operation status information of the artificial intelligence apparatus.

8. The artificial intelligence apparatus of claim 7 , further comprising a communication circuit configured to communicate with at least one external device,

wherein the device operation status further includes operation status information of the at least one external device.

9. The artificial intelligence apparatus of claim 8 , wherein the processor is configured to:

determine a calibration weight based on the utterance situation information, and

calibrate a frequency weight by multiplying a frequency weight by the calibration weight.

10. A computer-implemented method of recognizing speech of a user, the method comprising:

obtaining, via a microphone, speech data including speech of a user,

for each of a plurality of sections of the speech data:

calculating a probability for each of a plurality of words,

determining, using a speech recognition log, a frequency weight for each of the plurality of words,

for each of the plurality of words, calibrating the probability by multiplying the calculated probability by the determined frequency weight,

converting the speech data into text by (i) selecting, for each section of the plurality of sections, a word having a highest calibrated probability and (ii) combining the selected words, and

performing control based on the text.

11. The computer-implemented method of claim 10 , further comprising:

normalizing the calibrated probabilities, and

converting the speech data into the text by selecting, for each section of the plurality of sections, a word having a highest normalized calibrated probability.

12. The computer-implemented method of claim 10 , further comprising:

checking a usage frequency of a word using the speech recognition log, and

setting, based on usage frequencies of words, a frequency weight of a word to be higher than a frequency weight of another word.

13. The computer-implemented method of claim 12 , further comprising:

determining a private frequency weight for a word using a private speech recognition log,

determining a public frequency weight for a word using a public speech recognition log, and

calibrating a probability for a word using the private frequency weight and the public frequency weight,

wherein the private speech recognition log includes speech recognition logs in an artificial intelligence apparatus, and

wherein the public speech recognition log includes speech recognition logs in an external apparatus.

14. The computer-implemented method of claim 13 , further comprising:

determining an integrated frequency weight by calculating a weighted sum of a private frequency weight of a word and a public frequency weight of a word, and

calibrating a probability using the integrated frequency weight.

15. The computer-implemented method of claim 10 , further comprising:

determining utterance situation information corresponding to an utterance situation, and

calibrating a frequency weight for a word using the utterance situation information.

16. The computer-implemented method of claim 15 ,

wherein the utterance situation information includes at least one of a type of an artificial intelligence apparatus, an installation location of the artificial intelligence apparatus, a location of the user, a main user, and a device operation status, and

wherein the device operation status includes operation status information of the artificial intelligence apparatus.

17. The computer-implemented method of claim 10 , further comprising:

determining a calibration weight based on utterance situation information, and

calibrating a frequency weight by multiplying a frequency weight by the calibration weight.

18. A non-transitory processor-readable medium having recorded a program for performing a method of recognizing speech of a user, the method comprising:

obtaining, via a microphone, speech data including speech of a user,

for each of a plurality of sections of the speech data:

calculating a probability for each of a plurality of words,

determining, using a speech recognition log, a frequency weight for each of the plurality of words,

for each of the plurality of words, calibrating the probability by multiplying the calculated probability by the frequency weight,

converting the speech data into text by (i) selecting, for each section of the plurality of sections, a word having a highest calibrated probability and (ii) combining the selected words, and

performing control based on the text.