HVAC Control in the New Millennium.pdf - HVAC.Amickracing

HVAC Control in the New Millenniumsystems can use a learning process similar to Morse Code. Learningstarts with recognizing the dots, dashes, and spaces. Then, learningproceeds to recognize the characters without having to count the dotsand dashes. Next, you learn to recognize simple words and eventuallyget to predict complete sentences or phrases.Fast speech recognition requires that the system must be able torecognize common phrases. Since speech recognition systems are usedin specific application areas, the language of the particular applicationlike HVAC becomes the heart of the system’s common-word vocabulary.Speech Recognition TechniquesFour approaches or techniques for electronic speech recognitionexist. Acoustical techniques depend on the analysis of the speech waveform. Signal analysis can be done with Fourier frequency analysis, principalcomponent analysis and statistical decision making.The speech perception approach bases speech interpretation on theessential components of speech such as the length of the sounds, theseparation of vowel and consonant sounds, feature detection and linguisticcategories. Speech production techniques are based on the idea ofunderstanding how speech is produced in order to understand its meaning.Speech reception techniques duplicate the human auditory receptionprocess in a machine. It is based on observing how the ear receivessound and converts it into electrical impulses, and how the nerves transmitthe sound information. The concept is to replicate the process mechanically.Humans hear the contextual meaning between spoken words andpast experiences and these are used for speech interpretation, as well asthe physical gestures made by the speaker.Speech Recognition ProblemsSpeech recognition systems have some common problems. Theyneed to be able to identify the most probable answer, but the only systemthat can be expected to find exact matches is a voice print system.All systems require a means of receiving the sound waves and©2001 by The Fairmont Press, Inc. All rights reserved.