【作者】 魏绍亮；

【导师】 曹家麟； 陈一民；

【作者基本信息】 上海大学 ， 控制理论与控制工程， 2009， 博士

【摘要】 我国煤矿众多,煤矿自动化生产要求越来越高,但多年来煤矿井下信号提取和传输技术发展缓慢,各个厂家的产品采用不同的通信技术方式,形成了井下多种信道共存,多种通信方法共存的局面,很难建立一个覆盖全矿井的信息网络,以实现信息共享,严重制约了煤矿自动化的发展,甚至造成了每年大量的煤矿事故发生,造成生产人员大量伤亡、国家财产巨大损失。目前,还没有有效的方法来解决这一问题。本文就基于低压电力线的煤矿井下信号提取和传输技术进行了深入研究。该研究不仅具有理论意义,而且具有较大的实用价值。通过对类似煤矿井下的特殊环境信号提取和传输技术的研究,可建立相关理论和算法,另外,可将研究成果服务于特殊环境下的生产和安全需要,解决煤矿特殊环境下所面临的实际问题。基于低压电力线的数字信息网络建设的研究重点是信道建模和通信方法的研究。本文分别从煤矿井下低压电力线信道特性测试、信道建模和数字信息通信技术等三个方面出发,对煤矿井下基于低压电力线的数字信号提取与传输的关键技术进行了深入研究,主要研究工作和研究成果如下:1、提出并建立了基于小波矩阵扩展的煤矿井下低压电力线信道模型。目前基于低压电力线的信道建模研究基本上都集中在地面上低压电力线的信道上。其中最典型的信道建模方法主要有:基于多径效应的建模方法和基于传输矩阵的建模方法,这两种建模方法在煤矿井下信道建模上存在建模困难,实时调整性差等缺点,难以满足井下数字信息通信需要。实验表明,新建的模型具有建模准确,实时性强的优点,能够满足数字信息提取和传输的实时性要求。2、提出并建立了基于WAVELET-OFDM的井下低压电力线通信技术,推导得出了基于Daubechies小波基的WAVLET-OFDM分析和综合滤波器结构及算法,解决了OFDM通信技术在井下低压电力线上传输数字信息存在传输效率低,频谱特性差等问题,改善了系统的通信性能。3、OFDM技术在井下低压电力线上存在抗干扰性能差和峰均功率比高等问题。为克服此问题,本文建立了基于CLUSTER-OFDM的井下低压电力线通信技术,建立了基于低压电力线的子群分配机制。仿真实验结果证明了建立的CLUSTER-OFDM算法的有效性,可以有效地降低系统的计算复杂度,改善系统的峰均功率比,提高系统的可靠性。4、OFDM技术在煤矿井下低压电力线通信上表现出较强的频谱零点现象,即对某些频率点的信号传输误码率较高,影响了信号提取和传输。本文建立了基于PRECODED-OFDM的煤矿井下低压电力线信道数字信号通信技术。基于井下低压电力线的PRECODED-OFDM技术不同于无线通信领域的预编码技术,建立的结构简单、易于编码的预编码算法有重要意义,仿真结果表明本文所提算法能在计算量增加不大的情况下消除频谱零点问题,有效提高系统的通信质量。更多还原

【Abstract】 Nowadays there are many coal mines in our country. The automation of coal mine production is getting more and more important. While the development of signal extraction and transmission technology (SETT) underground coal mining is lagged. Communication network which can overcast the whole coal mine is difficult to establish, so the information sharing cannot work better because of different technique protocol used in different communication equipments. So the coal mine automation development is restricted badly. And even more, it could make large numbers of coal mine accidents, which could take a heavy number of casualties and national property loss. At present, there is not effective technology to solve this problem. SETT based on low voltage power line underground coal mine (LVPLUCM) is deeply researching in this work. Not only is the study theoretic meaning, but it has practical value. First of all, the theory and algorithm are built by researching SETT of special environments similar as underground coal mine. Second, the results of this research can be applied to production and safety of special environments and can resolve practical problem of underground coal mine.The research emphases of the high-speed digital network construction based on LVPLUCM is the channel modeling and the communication technique. The key SETT based on LVPLUCM were studied deeply, such as the methods of LVPLUCM characteristics testing, channel modeling and the technique of digital communications. The main research work and contributions are as follows:1. The channel model of LVPLUCM based on the expansion of wavelet matrix is built in the paper. Now, the researches of channel modeling based on LVPLUCM are concentrated on the channel of over ground low voltage power line. The most typical techniques of channel modeling are the method of modeling based on multi-path and transmission matrix. Both are difficult when they are carried out on the channel modeling underground coal mine due to the disadvantage of property of real time adjustment. The experiments show that the model is exact and the real time property of the model is excellent. The model can meet the requirement of real time property of digital signal extraction and transmission.2. In this paper the technique of LVPLUCM based wavelet-OFDM is proposed. The construct and arithmetic of the synthesis filter based on Daubechies wavelet-OFDM was built in this work. This technology can solve low efficiency and bad spectrum features of the OFDM. The communication performance can be improved through this technology.3. Capacity of resisting disturbance is not good enough and the PAPR is high when the technique of traditional OFDM was used on LVPLUCM to transmit digital signal. The technique based on CLUSTER-OFDM was proposed and cluster distribution mechanism was built in this paper. The simulation results verify the effectiveness of the proposed algorithm. The complexity was reduced efficiently, PAPR was improved and the system reliability was increased by using the technique of CLUSTER-OFDM.4. The bit error rate at some frequency is extremely high when the traditional OFDM technique was used in LVPLUCM, which effects the communication of signal information badly. The underground low voltage power line communication technique based on PRECODED-OFDM was built in this paper. The technique is different to the pre-coding technique in the field of wireless communication, so it is very important to build a simple structure and an easy coding process of the pre-coding technique. The conclusion of simulation shows that the problem of bad null-spectrum can be solved using the technique built in this work with a little increment of calculation. And the efficiency of communication can be improved observably.更多还原