数字化智能型公共广播系统的设计

【作者】 孙凯；

【导师】 杨公源；

【作者基本信息】 天津工业大学 ， 控制理论与控制工程， 2004， 硕士

【摘要】 公共广播又称有线广播，简称PA广播(Public Address System)，是在一定的区域范围内传播实时信息的重要手段，主要用于飞机场、火车站、汽车站、体育场、商场和超市等场所，其主要任务是为公共场所提供清晰的富有效率的声响环境。 本文借鉴国内外公共广播系统的特点，针对车站公共广播的特点和要求，开发了一数字化智能型公共广播系统。 在控制上，采用了分布式控制方式，由语音计算机进行音源输入和输出的切换，执行业务性广播、服务性广播和火灾事故紧急广播；由控制计算机进行系统的监控，监视功率放大器和扬声器回路的工作状态，并根据当前的设备状态执行相应的控制任务。下位机(单片机)采集功率放大器等系统设备的信息，并按照预定的算法执行现场控制。 在硬件上，采用DSP语音处理技术，由高品质的DSP2000音频卡进行音频信息的采集、量化和编码操作，不但提高了音频的质量，也提高了音频处理的速度。 在软件上，采用面向对象的编程技术，充分利用Windows强大的多媒体技术，对多路输入信源进行WaveX的底层音频编程，实现了上位机对音源输入输出的灵活控制；为了保证音频信号处理的实时性，软件上还充分利用了Windows多线程技术，采用了基于“生产者-消费者”模式的多线程技术。 本公共广播系统的设计，充分利用了现代数字通信技术、计算机技术和电子技术，从功能上和技术上实现了数字化智能型公共广播系统的设计，达到了厂方的要求，本人也得到了极大的提高。更多还原

【Abstract】 The public broadcast system which is called public-address system is called PA system for short . It is an important method to propagate the real-time information in a certain space. It is primarily used for the airports, train stations, bus stations, stadiums and the large supermarkets. It’ s main function is to provide clear and full of efficiency audio environment.The digital intelligent PA system uses the experience of world PA system for reference and in connection with public broadcast system’ s special features .It has seven peculiarities.The system cybernation method is distributed control system . In this way , the audio process computer switch the signal between input and output channels .The main function of audio process computer is general broadcast , service broadcast and emergency broadcast . There is a special control computer .It’ s main function is supervise-control the system status such as the amplifier and speaker circuit . It also send control instructions to SCMs which collect information of system facilities.The core hardware facilities is DSP card which is produced by Korea . The audio information is sampled and measured and coded by the DSP card . The process speed is quick .There are a filter circuit ,a power check circuit and a range-frequency characteristic check circuit which are designed to check the system status . The most important technology is a switch matrix which is make up of special radio tubes . It prolongs the system work life-span and reduce noise.This system adopts object-oriented technology . It takes full advantage of Windows multimedia technology .The audio input signals are programmed by this technology in WaveX pattern . In order to process the input audio signals in real time, Windows Thread technology is alsoadopted .The thread technology is a "producer-consumer" mode.This thesis takes full advantage of modern communication technology , computer technology and electronic technology .It realizes the purpose of designation . Fortunately ,I have learned much useful knowledge and have made a progress of my study through write the thesis.更多还原