基于嵌入式系统的煤矿动态轨道衡计量精度的研究

发布时间：2018-01-04 20:01

本文关键词：基于嵌入式系统的煤矿动态轨道衡计量精度的研究　出处：《贵州财经大学》2012年硕士论文　论文类型：学位论文

【摘要】：近年来，随着计算机技术的飞速发展和硬件设备的换代升级，嵌入式开发技术走上了独立发展道路，各种嵌入式设备越来越多，嵌入式操作系统在多种领域得到广泛应用，尤其是工业控制领域。其中动态轨道衡就是嵌入式开发技术与工业自动化控制相结合的一个重要产品。在我国，动态轨道衡产生于二十世纪70年代末期，由于受到当时科技手段的限制，其应用的范围较小，产品更新换代比较慢。直到80年代末期，动态轨道衡计量技术才取得突破性进展，动态轨道衡在运输领域得到广泛应用，主要安装在车站、港口、矿山等装有铁路专用线的轨道上，保证在车辆不停车的情况下计量其装载量，为企业的生产活动和国家的监管提供参考。进入二十一世纪之后，动态轨道衡广泛应用在煤矿、铁矿等大型矿产资源开采企业中，主要用于计量企业的生产能力。但是矿产企业的生产环境比较恶劣，其最主要的特点是高温、高湿、空气中粉尘多、电磁波干扰强、噪声污染严重，这些与铁路运输中的环境差别较大，因此如果将铁路运输中使用的动态轨道衡系统直接应用在矿产企业中，其计量精度将会严重削弱，无法准确计量矿车的重量。在对原有铁路动态轨道衡计量系统进行改进的基础上设计了煤矿动态轨道衡计量系统。本论文将分别从硬件设计和软件算法两个方面就如何提升该系统的计量精度进行研究，使其能够满足在特殊环境条件下的计量要求。首先从硬件方面出发，在选择称重传感器的型号时，为了提升系统的计量精度，需要选择计量精度高、采集频率快的电阻式应变片式传感器作为数据采集器，优化信号放大电路的设计，，对采集到的电压信号进行放大处理，同时消除零漂现象。利用信号滤波电路对采集到的模拟信号进行滤波操作，去除因环境影响而产生的干扰波。将信号滤波电路与A/D转换电路连接，把模拟电压信号转换为数字电平信号。整个过程中采用独立电源电路供电，并将电源安装在相对封闭的金属箱中，以减少电磁干扰，同时将电源进行接地操作。在信号传输过程中，采用RS-485总线传输，摒弃过去的RS-232工业总线传输方式，可以有效的增强信号在传输过程中的抗干扰性和减少信号的衰减。从软件方面出发，在MATLAB仿真模拟环境中利用信号处理算法对采集的信号进行分解，去除高频信号的干扰，最终得到有效的数据波形。首先对数字信号进行截取操作，设定阀值为25，舍弃阀值低于25的数字信号。分别使用经验模态分解算法和小波算法对数字信号进行分解，将分解的信号乘以转换系数后得到矿车的真实重量，记为测量值。将测量值与实际值带入公式进行运算，最终得出两种算法的计量精度。对两种算法的计量结果进行比较，将计量精度高的算法作为最终的信号处理算法。
[Abstract]:In recent years, with the rapid development of computer technology and the upgrading of hardware, embedded development technology has been on the road of independent development, and more and more embedded devices. Embedded operating system is widely used in many fields, especially in industrial control field, in which dynamic track scale is an important product which combines embedded development technology with industrial automation control. In our country, dynamic track scale came into being in the end of 1970s, because of the limitation of scientific and technological means at that time, its application scope is relatively small, the product renewal is relatively slow, until the end of 80s. Dynamic rail scale metering technology has made a breakthrough. Dynamic rail scale has been widely used in the field of transportation, mainly installed in railway stations, ports, mines and other railways equipped with special railway lines. In order to provide a reference for the production activities of enterprises and the supervision of the country, the dynamic track scale has been widely used in coal mines since 21th century. In large mining enterprises of mineral resources such as iron ore, it is mainly used to measure the production capacity of enterprises. However, the production environment of mineral enterprises is relatively bad, the main characteristics of which are high temperature, high humidity and much dust in the air. The electromagnetic wave interference is strong, the noise pollution is serious, these are quite different from the railway transportation environment, therefore, if the dynamic track scale system used in the railway transportation is directly applied in the mineral enterprises. Its measuring accuracy will be seriously weakened, can not accurately measure the weight of the mining car. Based on the improvement of the original railway dynamic rail scale metering system, a coal mine dynamic rail scale metering system is designed. In this paper, how to improve the measurement of the system from the aspects of hardware design and software algorithm is presented. Precision is studied. In order to improve the measurement accuracy of the system, it is necessary to select the high measurement precision in order to improve the measurement accuracy of the system. Firstly, from the hardware aspect, when selecting the model of weighing sensor, it can meet the measurement requirements of special environment. The high frequency resistive strain gauge sensor is used as the data collector to optimize the design of the signal amplification circuit and amplify the collected voltage signal. At the same time, the zero-drift phenomenon is eliminated. The signal filter circuit is used to filter the collected analog signal, and the interference wave caused by the environment is removed. The signal filter circuit is connected with the A / D conversion circuit. The analog voltage signal is converted into digital level signal. During the whole process, the power supply is supplied by a separate power supply circuit, and the power is installed in a relatively closed metal box to reduce electromagnetic interference. At the same time, the power supply is grounded. In the process of signal transmission, RS-485 bus is used to transmit, and the past RS-232 industrial bus transmission mode is abandoned. It can effectively enhance the anti-interference and reduce the attenuation of the signal during the transmission process. From the software aspect, the signal processing algorithm is used to decompose the collected signal in the MATLAB simulation environment to remove the interference of the high-frequency signal. Finally, the effective data waveform is obtained. Firstly, the digital signal is intercepted and the threshold is set to 25. The empirical mode decomposition algorithm and wavelet algorithm are used to decompose the digital signal, and the decomposed signal is multiplied by the conversion coefficient to get the real weight of the mine car. Take the measured value and the actual value into the formula to calculate, finally get the measurement accuracy of the two algorithms, and compare the measurement results of the two algorithms. The algorithm with high measurement accuracy is regarded as the final signal processing algorithm.
【学位授予单位】：贵州财经大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH715.13;TP368.1

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