太原理工大学 硕士学位论文 无测速传感器电子皮带秤的研究与实现 姓名：王志爱 申请学位级别：硕士 专业：控制理论与控制工程 指导教师：段承先 20090401 太原理工大学硕士研究生学位论文 I 无测速传感器电子皮带秤的研究与实现 摘 要 本文是以太原某自动化仪表有限公司的研发项目“无测速传感器电子 皮带秤系统的实现”为研究背景撰写而成的。 电子皮带秤是皮带输送机输送固体散状物料过程中对物料进行连续称 重的一种计量设备，是工业生产过程中应用最为广泛的设备之一。在称重 精度要求较高的现代化流水线作业环境中，电子皮带秤性能的优劣对于工 业生产的效率和质量有着很重要的作用。传统的电子皮带秤中都包含有测 速传感器。由于测速传感器属于精密易损器件，而电子皮带秤的使用环境 一般比较恶劣，极易造成传感器损坏。另外，测速传感器可由于人为作弊 等因素导致称量失真，给国家、企业造成严重损失。而且，当电子皮带秤 用于配料系统时，称量失真还会严重影响配料后产品的质量。所以，测速 传感器的选择和替代问题成为近年来相关学科和专家关注和研究的课题。 本文设计的无测速传感器电子皮带秤是在双通道电子皮带秤基础上研 发实现的。其基本原理是去掉皮带秤中的测速传感器，而在两个托辊上分 别安装两组重量传感器，按照皮带运转方向确定前通道和后通道。通过对 两个通道采集回来的重量信号进行比较分析，应用数字信号处理理论中互 相关函数的理论，采用相关卷积及快速傅立叶变换等计算方法，直接从重 量信号中提取出速度信号，再根据皮带秤的有效称量长度、托辊间距等一 些参数，计算出皮带运转的速度，进一步得到皮带秤上物料的流量及累计 量。 太原理工大学硕士研究生学位论文 II 文中分析了无测速传感器电子皮带秤实现的理论基础，给出了理论实 现的算法并进行了仿真分析。详细介绍了系统的硬、软件设计，包括：主 控芯片的选型及电路设计；电源电路、数据采集模块及上位机管理软件的 设计；称重显示控制器与上位机的通讯及控制面板的设计等。在理论设计 的基础上，绘制了 PCB 板图，进行了整机调试。 实验研究表明：本文设计的无测速传感器电子皮带秤，可以省掉皮带 秤中的测速传感器，从而减少皮带秤的损坏机率，提高皮带秤的称量精度 和运行的可靠性。 关键词：双通道电子皮带秤，数字信号处理，互相关函数，傅立叶变 换 太原理工大学硕士研究生学位论文 III The Research and Realization of the Conveyor Belt without Speed Sensor ABSTRACT The article is based on the research of an automation instrumental company in Taiyuan which named “The Realization of the System of the Conveyor Belt Scale without Speed Sensor”. The electronic conveyor belt scale is a kind of measuring equipment used to measure the weight of the solid bulk materials during the working condition, and it is one of the most widely used equipment in industrial. In the assembly line operating environment that needs high precision, the electronic conveyor belt scale plays an important role in the industrial production efficiency and quality. The traditional electronic conveyor belt scale includes speed sensors. The speed sensors are precision and vulnerable devices, and the working condition of the electronic conveyor belt are very bad, so it is easily to be damaged. Because of the speed sensor can be damaged by man-made factors such as weighing cheating distortion, making the state, enterprises causing serious losses. In addition, when the electronic conveyor belt is used for batching systems, weighing ingredients distortion will seriously affect the quality of the product. Therefore, the selection and alternative questions of the speed sensor becomes a research topic in recent years. 太原理工大学硕士研究生学位论文 IV In this article, the design of electronic conveyor belt scale without speed sensor is based on the dual-channel electronic conveyor belt. The basic principle is to remove the speed sensor, and place two weight sensors on each roller. According to the belt running direction, it is determined the previous channel and the after channel. Comparing and analyzing of the signals collected from the two channels, applying theoretical knowledge of cross-correlation function from digital signal processing theory, using the computing method of convolution principle and Fourier transformation to abstract speed signal from weight signal directly. Thereby we could base on the parameters such as active weighing length and roller extent to calculate the strap operating speed, then get the flow of the conveyor belt. In this disquisition, the author analyzed the basic theory of realizing the conveyor belt scale without speed sensor, supplied the algorithm of theory realization and processed the simulation analysis and introduced systems hardware and software design in detail, which included: the type choosing of main control chip and circuit design; the design of power source the communication between weighting indicator and upper PC software and the design of control panel. On the base of theory design, author drafted the PCB layout and processed the adjustment of whole machine function. The results of experiment showed that electronic conveyor belt scale created by author with non-speed measurement transducer could leave the speed 太原理工大学硕士研究生学位论文 V sensor out of the belt scale so that to reduce the damage rate of belt scale and to improve its weighing precision and operation reliability. KEY WORDS: the dual-channel electronic conveyor belt scale, digital signal process, the cross-correlation function, Fourier transformation 太原理工大学硕士研究生学位论文 IX 图表索引 图 2-1 承重装置秤架结构示意图 . 7 图 2-2 两组重量信号采样波形图 . 8 图 2-3 蝶形运算的信号流图 . 14 图 2-4 算法流程图 . 17 图 2-5 原始曲线 . 17 图 2-6 互相关函数曲线 . 18 图 2-7 样机试验中原始曲线 . 18 图 2-8 样机试验中互相关函数曲线 . 19 图 3-1 无测速传感器电子皮带秤产品型号格式 . 20 图 3-2 我测速传感器电子皮带秤系统结构框图 . 22 图 4-1 称重显示控制器硬件框图 . 25 图 4-2 CPU 部分的电路图