Design Of Wireless Speech Control System Based On PC Platform

Intelligent Instruments and equipments have been developing towards toadvanced intelligent instruments along with the rapid progress of computerhardware and software technology, micro electric technology, communicationtechnology, network technology, artificial technology. Advanced intelligentinstruments that have natural Human Machine Interface are creative.In this thesis, Human Machine Interface is greatly improved andintelligent instruments and equipments are controlled in network andintelligence by applying speech recognition combined with ZigBee wirelesstechnology, based on PC platform. Main work of this thesis is listed as follow:1) Do research on key technology of small and medium vocabularyspeaker un-depended continuous speech recognition, analyze thecharacteristics of wireless ZigBee technology, and bring up the idea ofapplying speech recognition and ZigBee technology for the long distance andintelligence control of advanced intelligent instruments and equipments.2) For wireless speech control application, design and record a speechdatabase for small and medium vocabulary speaker un-depended continuousspeech recognition.3) Using the self-designed speech database, test the influence of differentfeature vector dimension for speech recognition correct rate. And bring upscatter algorithm for this speech database, experiments have shown thatcorrect rate can be improved maxim 88% after using scatter algorithm.4) Based on the HTK toolkit, using syllable as recognition unit andregulation language model, the correct rate and accuracy of speechrecognition system are 99.51% and 94.43% individual.5) Design and implement ZigBee wireless commutation platform basedon PIC MCU and CC2420 chip. ZigBee stack and its reduced version areimplemented on PIC MCU, and star network is also constructed. For thedesigned ZigBee nodes, commands signals can be transmitted maxim 130mand ZigBee node current consumption is only 0.20mA. This thesis can be divided into five chapters and introduces basic theoryof wireless speech control and ZigBee technology in detail. For the design andimplementation of the wireless speech control system, detail steps are given.Experiments show than impossibility and advantage using speech and wirelesstechnology for intelligent instruments and equipments.Chapter 1 is an introduction that introduces the characteristics advancedintelligent instruments and equipments, and key technology. And finally theresearch meaning is given.Chapter 2 introduces speech signal processing in detail, including speechproduction model, speech signal processing methods and HMM.Chapter 3 gives the whole design process of the wireless speech controlsystem based on PC. It also introduces speech database design and record,speech recognition based on HTK and ZigBee node design.Chapter 4 is the test results of the wireless speech control system.Chapter 5 is the conclusion of this thesis and gives some advice for thework in the future.