Design And Implementation Of The Loud Acoustic Disperse System

The system of loud acoustic disperse is to transmit high-intensity audible sound waves with directionality after processing voice signals such as screaming,warning and dispersal by police personnel.This kind of audible sound waves won't not only cause fatal damage to the human body,but also as deterrence in the process of dealing with mass incidents,which has significant application value for the development of future police equipment.Based on the DSP digital signal processing technology,this paper studies and analyzes the basic theory of speech signal processing.Through the selection and construction of the hardware platform,the hardware circuit of the speech signal processing module is researched and improved.It is designed with the power amplifier and horn loudspeaker array.The directional,loud acoustic disperse system enables it to emit high-intensity audible sound waves.Based on the theory of speech signal processing,this paper studies and designs a loud acoustic disperse system.Its main work and innovation is as follows:(1)Based on the theory of speech signal processing,the speech signal processing methods such as real-time analysis method and frequency domain analysis method,speech signal preprocessing,and wavelet transform used in speech signal processing was deeply studied and analyzed.The structure,working principle and hardware development platform of DSP chip are studied.The performance characteristics of DSP chip and audio codec chip are analyzed.TMS320VC5509 A was selected as the digital signal processing chip and TLV320AIC23 B as the audio codec chip,based on the above elements,a loud acoustic disperse system hardware platform is established.(2)In the construction of the hardware platform,the overall hardware structure circuit of the system is mainly designed,including the design of the system power supply circuit,the circuit design of the JTAG interface module,the circuit design of the external memory module,the circuit of the DSP chip and the audio chip,design of input and output circuits for connection design and audio signals,power amplification circuits for audio power amplifiers,and detailed analysis of the functions of each module.(3)Performance testing of the system.In the process of testing,the FIR digital filter based on DSP was designed and improved according to the characteristics of high-frequency signal interference of voice input.Through emulation,it realized the characteristics of the better filtering-out and high-frequency signal on DSP chip.At the same time,the whole system was tested for sound pressure level and directivity,and the sound pressure value and all-directional directionality of the system were analyzed in detail.