【作者】 谭谦；

【导师】 陈晓冬；

【作者基本信息】 天津大学 ， 光学工程， 2010， 硕士

【摘要】 城市环境噪声监测是环境监测系统的主要监测项目之一。目前,在我国大多数城市中,环境噪声监测采用一年监测若干频次和时段的手工监测方法,实时性和连续性差,很难及时发现突发性的噪声污染事故,不利于环保部门从宏观上掌握城市的总体环境污染水平。因此,环境噪声实时在线自动监测系统的开发成为环境监测部门亟待深入开展的工作。数字环境噪声自动监测系统由设在监测点的数个全天候环境噪声监测终端、传输线路以及噪声数据管理中心组成,是传感技术、微机电技术与现代通信技术相结合的产物。本课题针对城市环境噪声自动监测的实际需求,将传统的模拟式声级计加以数字化改进,在TMS320C6713 DSP芯片中实现频率计权、时间计权与FFT频谱分析。以ARM9为主控芯片,对监测终端进行控制。实验表明,该监测终端可以很好的实现环境噪声实时在线自动监测的功能。论文主要完成了以下工作:针对环境噪声监测的实际需求进行分析,提出了数字环境噪声自动监测终端的整体设计方案,采用TMS320C6713 DSP芯片对声信号进行处理,ARM处理器S3C2440对系统进行控制。完成DSP芯片最小系统板的PCB设计与调试。在DSP中实现声信号的频率计权、时间计权与FFT频谱分析。利用软件模拟异步时序,实现DSP中同步串口McBSP与ARM中异步串口UART的通信。以S3C2440作为系统的主控芯片,控制SIM300模块,实现监测终端与数据中心的无线通信。控制CMOS摄像头,完成对现场突发事件的抓拍以及图像的JPEG压缩与图像数据的传输。通过实验证明频率计权与时间计权均满足IEC61672-2002对于1级声级计的要求,整机精度可达0.1dB。系统具有良好的频谱分析功能,样机可以长时间稳定地向数据中心传输数据,满足环境噪声实时在线自动监测的要求。更多还原

【Abstract】 The city environmental noise monitoring is one of the primary environmental monitoring projects. Currently, the environmental noise is monitored with manual monitoring methods in most cities of China. For its poor real time property and continuity, it is difficult for environmental protection departments to control the city’s overall environmental degradation. Therefore, the development of environmental noise automatic monitoring system is an urgent job.The digital environmental noise automatic monitoring system is composed of several noise monitoring terminals, the transmission connection and the noise data administering center, which combines the sensor technique , computer technique and the modern communication technique. This paper proposed a structure and realization scheme of the digital environmental noise automatic monitoring system which can satisfy the requirements of the city environmental noise monitoring. A robust, high accurate, real-time system using floating-point DSP (TMS320C6713) chip as core processor to finish frequency weighting, time weighting and FFT, and the high-performance S3C2440 single chip processor as data collection and port controller is presented.The main jobs of this paper are as follows:Firstly, according to the need of environmental noise automatic monitoring, a novel structure and realization scheme is proposed.The sound signal is processed in TMS320C6713 and the whole system is under the control of S3C2440.Secondly, the design of the DSP circuit is completed. And the frequency weighting, time weighting and FFT are realized in DSP. A method using the multichannel buffered serial port McBSP to emulate software UART is provided.Thirdly, the program design of the S3C2440 is completed. The noise data is transmitted through GPRS with SIM300. The CMOS camera can work well under the control of ARM. Image compression and transportation are completed.Lastly, the experiment proved that the accuracy of frequency weighting and time weighting meets the IEC Standard IEC61672-2002 class I, and the system accuracy is up to 0.1dB. The system has good spectral analysis performance, and can work stably for long time, which meets the requirements of the environmental noise monitoring.更多还原