矿用高频低功耗便携式无线振动传感系统设计

高频信号的低功耗无线传输在煤矿工作面一直存在技术难题。针对工作面的具体环境状况,结合多类无线总线通讯的特点,研制了一种基于蓝牙的无线振动传感器和具有安卓和嵌入式双内核的基于蓝牙和Lora的诊断分析系统。文章介绍了该系统的总体设计和详细设计与实现,利用该系统可实现对工作面多种不同类转子设备的振动诊断分析,保障工作面关键设备的长期稳定运行,降低工作人员的劳动强度。     

Experimental analysis of wet mill load based on vibration signals of laboratory-scale ball mill shell

Real-time measurement of the mill load is the key to improve the production capacity and energy efficiency for the grinding process. In this paper, experimental analysis of the wet mill load based on the vibration signals of the laboratory-scale ball mill shell is presented. A series of experiments are conducted to investigate the vibration characteristics corresponding to different grinding conditions such as dry grinding, wet grinding and water grinding. The power spectral density of the vibration signals is systematically interpreted.Experimental results show that the rheological properties of the pulp affect the amplitude and frequency of the vibration signal. The most important conclusion is that the frequency range of the shell vibration of the laboratory wet mill can be divided into three parts, namely natural frequency band, main impact frequency band and secondary impact frequency band. Finally, soft-sensor models between vibration signal and mill operating parameters of mill load are established using genetic algorithm-partial least square (GA-PLS) technology. After more work on industry scale ball mill is done, the soft-sensor modeling based on the mill shell vibration for operating parameters of mill load will improve the performance of the ball mill in the grinding process.     

基于LabVIEW的虚拟信号分析仪在动态信号分析中的应用

通过对由LabVIEW开发的信号分析仪的具体实例的分析 ,介绍了虚拟仪器的特点和应用 ,体现了虚拟仪器的良好功能。该分析仪实现了小波去噪和频谱分析等功能 ,在实验室应用和对于具体信号的处理都有很好的效果     

The effect of orderly vibration on pickforce sensing

ABSTRACT

Pickforce sensing is a method developed for automating the guidance of coal mining machines. Its objective is to determine the vertical location of a rotary cutting machine from the force measured at the point of contact between the machine and the coal seam. A phenomenon that may degrade the reliability of the pickforce data is vibration, and is the concern of this study. The effects of vibration may either be orderly or chaotic. The focus of this paper is on the orderly (repetitive) effect which may mask the pickforce data. To analyze this effect, a vibration model of the cutting process is first developed. Subsequently, the vibration model is explored to (a) demonstrate that the orderly effect does no reduce the reliability of the pickforce data, and (b) suggest alternative means in improving the quality of pickforce records by modifying parameters of the cutting machine     

Investigation on measuring the fill level of an industrial ball mill based on the vibration characteristics of the mill shell

A novel characteristic variable of fill level has been proposed, in order to reduce the influence of various factors on measuring the fill level and improve the measurement accuracy of the fill level. A relationship was developed between the fill level and the angular position of the maximum vibration point on the mill shell through theoretical calculation and on-site experiments. This relationship was studied theoretically with two assumptions. The vibration signals were then collected by an accelerometer mounted directly on the mill shell, and analyzed on the time domain to obtain the maximum vibration point on the mill shell, in order to study the correlation between the fill level and this angular position.Both the results of theoretical calculations and experiments show that the position of the maximum vibration point on the mill shell moves to a lower angular position as the fill level increases. Comparison of the traditional and the new characteristic variable of the fill level reveals that the characteristic variable proposed in this paper is more superior and stable. It shows potential for measuring the fill level more accurately.     

基于振动信号的采煤机煤岩截割状态识别

为了准确识别采煤机截割状态,提出了一种基于小波包分解和学习向量量化(LVQ)神经网络的模式识别方法。将振动信号进行小波包分解,实现振动信号的预处理,得到若干个子频带。在此基础上,计算各个频带的方差,并将其作为特征向量。然后将计算得到的频带方差作为特征向量,输入到LVQ神经网络进行采煤机煤岩截割状态识别。通过实验验证了该方法的有效性,实验结果表明:该方法能够实现采煤机典型煤岩截割状态的识别,平均识别准确率较高,对实现综采工作面的"无人化"具有重要意义。     

遗传算法优化的振动磨机模糊控制器研究

振动磨机负荷控制的目的,就是在保证磨机稳定运行的条件下尽量提高磨机生产效率。根据磨机的延迟、非线性和不确定性等特点,该文设计了单变量输入—输出二维模糊控制器。并且考虑到经典模糊控制设计方法存在着很大的主观性和随意性,因此,采用遗传算法赋予模糊控制器学习功能,用自然进化和基因遗传学原理的优化搜索方法,使系统获取最佳的控制效果。     

隧道爆破振动信号时频谱增强优化分析

针对隧道爆破振动信号时频解析度不足的难题,运用基于卷积神经网络的时频图像增强算法,增强实测隧道爆破信号时频图像,捕获到爆破信号能量在时频域上的聚集范围,从而重构得到反映爆破特征的真实信号;根据真实信号对爆破网络中雷管的起爆时刻进行了精确判别,识别隧道爆破雷管灾害源特征。分析表明：基于卷积神经网络的时频图像增强算法可有效抑制信号中的交叉项,最大限度地保留信号自有项,提高爆破信号能量聚集性和时频解析度;不同批次雷管混用是隧道安全的主要致灾因素,应加强监管以实现隧道安全高效施工。     

振动磨机介质的运动规律及工作参数的算法

通过对MZS型振动磨机磨筒内介质运动规律的观察研究,建立了一个简单的介质运动学模型,并根据所建立的模型计算了振动磨机的一些重要参数,如振幅、介质填充率、介质直径等工作参数的最佳取值范围,从而使振动磨机获得最佳粉磨效果和降低能耗。     

重载汽车齿轮变速箱振动信号与结构模态特性分析

针对重载汽车齿轮变速箱的工作特点,对该齿轮变速箱的振动信号进行了功率谱分析和倒谱分析,并用有限元软件对该齿轮变速箱进行了结构模态分析。分析结果为研究以减振降噪为目的的齿轮变速箱结构动力学优化设计奠定了基础。     

Experimental investigation of load behaviour of an industrial scale tumbling mill using noise and vibration signature techniques

Mill load (i.e. the load level of coal powder), which is critical in improving the production capacity and energy efficiency of pulverizing system in thermal power plant, has not been effectively monitored and controlled industrially. This paper investigates the load behaviour in an industrial scale tumbling mill under practical working conditions. A microphone and an accelerometer were installed to pick up mill noise and inlet trunnion vibration signals, respectively. By analyzing the sensitivity distributions of mill noise energy and mill vibration energy, characteristic power spectra (CPS) of mill noise and mill vibration were obtained. The CPS energy, centroid frequency and frequency domain variance of the mill noise and mill vibration were then investigated and compared under various working conditions.Experimental results show that the CPS energy of both mill noise and mill vibration can accurately represent the mill load. Moreover, the centroid frequency and frequency domain variance of mill noise can also be used to determine mill load. By combining these characteristics of mill noise and mill vibration, an improved estimation of mill load can be achieved.     

噪声背景下矿井无线通信的弱信号检测技术

文章介绍了我国煤矿井下无线通信现状，分析了技术上存在的难题——巷道条件对无线传输的影响、弱信号接收困难和井下环境噪声的干扰，对解决途径进行了探讨。同时指出．陆地移动通信技术解决方案完全可以解决煤矿井下无线通信难题。     

矿山自动能量捕获和无线智能传感技术在亚克斯铜镍矿的应用

针对矿山地下供电系统稳定性低、监测传感器维护量大、监测系统经济性差、故障率高等实际难题,采用现场调研、理论计算、系统建模、软件仿真与现场测试等方法研制了能量捕获与智能管理装置、故障自诊断智能传感装置、无线智能传感交互技术与装备,并结合亚克斯铜镍矿的矿山特点将研究成果与矿山需求相融合,形成了具有自动能量捕获和故障自诊断能力的应力点监测传感装置,并与高精度微震监测系统组合成兼具区域监测与点监测的地压监测系统,建立了矿山地压安全分析预警云服务平台,有效提升了矿山的安全生产水平。     

球磨机衬板在一段磨机上的应用

介绍了近十年金岭铁矿球磨机衬板在一段磨机上的的使用情况，通过对比分析，总结出磨机衬板的理想组合，从而达到节能、增效的目的。     

Optimal mill cut-off grade modeling in the mineral deposits via MIP: Haftcheshmeh copper deposit

Cut-off grade play a critical role in defining tonnages mined and processed, average grade of mill feed, cash flows, mine life time, and all major characteristics of a mineral deposit. Simply, the cut-off grade is the lowest grade at which material is considered ore and is processed to create a concentrated commodity product. Essentially, it asserts that the mill cut-off grade is a function of the ore availability and the needs of the mill. The focus of this paper is upon one of these long time-scale decisions: whether to process the extracted material, or to waste it. Consequently, an effort is made for the development of a model for optimization of mill cut-off grade which considers grade blending of mineral deposit. A new mixed integer programming (MIP) model is proposed to deal with this objective and with this model determined the mill cut-off grade of Haftcheshmeh Copper deposit. The results show the obtained mill cutoff grade from proposed model generates the optimum average grade. Therefore, generated net value (NV) from this model is nearer to reality.     

基于CAN总线及无线传感技术的液压支架压力监测系统

工作面液压支架的支护问题一直是围绕煤矿生产安全和提高工作效率的重要问题.论文介绍一种采用无线传感技术,将传感器采集到的信号通过无线模块发送给工作面检测分站,检测分站将接收到的数据进行处理后通过CAN总线上传给顺槽通信总站,并由通信总站将数据通过以太网传至地面监测站的方案.该系统实现了对工作面支架压力信号的采集、处理、传输和分析及对其在工作面、巷道和井上监控室的全面监测.     

模式自适应小波时能密度法及其在微差爆破振动信号分析中的应用

如何解决适合爆破振动信号特征的爆破振动信号小波基构造、添加及其实现等问题,始终是困扰广大研究者的难题。为准确确定微差爆破振动信号实际微差延迟时间,在模式自适应小波原理的基础上,构造了从实测微差爆破振动信号中分离出子信号的模式自适应小波基,然后将该模式自适应小波基添加到Matlab小波分析工具箱中,并提出了一种新的基于爆破振动信号分析的模式自适应小波时能密度法。以实验设计的多段微差爆破振动信号进行模式自适应小波时能密度法分析为例,验证了该方法的可行性。该方法亦可用于分析实测微差爆破振动信号在实际微差延迟时间的确定,并与db8小波法和模式自适应小波法进行比较,结果表明模式自适应小波时能密度法具有更好的应用效果,从而为爆破振动信号分析在实际工程中的应用提供了参考。     

Measurement system of the mill charge in grinding ball mill circuits

Investigation of a dry fine grinding circuit has shown significant influence of the mill load (powder filling) on the production capacity. To improve the circuit performance at industrial scale, alternative ways of mill load measurement were investigated. Detection of strain changes in the mill shell during mill rotation, by using a piezoelectric strain transducer, provided very interesting results, allowing evaluation of the weight of the mill charge and control of the powder filling to obtain an optimal level. Power draw has thus been increased by about 5% compared to the old configuration where mill motor power input was used to control the mill charge. By measuring mechanical vibration with the transducer, additional useful information has been obtained about the behavior of the cataracting and cascading balls inside the mill shell. Finally an important factor was simplicity and low investment cost of the total installation, as many fine grinding mills operate in relatively small circuits that do not warrant large investment for alternative measurement methods.