磨粉机电动轧距控制模型方案的论证

为了在磨粉机工作时精确控制磨辊轧距,新建了一种磨粉机电动轧距控制模型并进行了原理分析,继而对该模型进行MATLAB仿真分析.结果表明,轧距控制达到了0.02mm的精度,且系统的时域响应有不错的表现.     

磨粉机磨辊轧距自动调节的实现

针对目前磨粉机中磨辊轧距调节方式落后,工作强度大,效率差的问题,提出了磨辊轧距自动调节的方案。采用ST72141专用电机控制芯片构成无刷直流电机控制系统,驱动电动轧距调节机构实现磨辊的快速离合轧和轧距自动调节,从而提高磨粉机的自动化程度,保证物料研磨的最佳效果。该控制系统具有线路简单、控制方便、保护功能完善,以及成本低、可靠性高、性能强等诸多优点,     

磨粉机磨辊轧距自动调节的实现

针对目前磨粉机中磨辊轧距调节方式落后,工作强度大,效率差的问题,提出了磨辊轧距自动调节的方案.采用ST72141专用电机控制芯片构成无刷直流电机控制系统,驱动电动轧距调节机构实现磨辊的快速离合轧和轧距自动调节,从而提高磨粉机的自动化程度,保证物料研磨的最佳效果.     

对辊式磨粉机在魔芋精粉加工中的应用

对辊式磨粉机是加工魔芋的一种有效设备。影响魔芋颗粒研磨质量因素有磨辊转速、喂料量、轧距、温度环境。本文主要研究对辊式磨粉机轧距对魔芋颗粒研磨质量的影响,通过轧距调节系统中慢辊轴承座和可动偏心轴的受力分析,分析结果得出设计角度α在45°附近,可动偏心轴能达到自锁条件,使对辊式磨粉机在工作状态下轧距保持稳定,为优化对辊式磨粉机在魔芋精粉加工中的应用提供理论基础和参考依据。     

影响磨辊磨损失重的技术参数优化

磨辊是辊式磨粉机的关键和易损部件,目前存在磨损严重、寿命短等问题。本试验以磨辊表层材料低铬白口铁为耐磨试样,以小麦籽粒粉料为磨料,采用与辊式磨粉机工况相似的三体磨料磨损试验机进行磨损试验,应用响应曲面设计对比分析了磨料粒度、转速和轧距对试样磨损性能的影响,确定了磨损失重最小的工况条件。结果表明:各个因素对磨损失重影响的显著性依次为:粒度、转速、轧距。因素之间的交互作用中,粒度和转速对磨损失重的影响较显著,其他不显著;粒度为1.00 mm、转速为400 r/min、轧距为0.25 mm,是降低磨损量的最佳参数组合,完成设定磨程的磨损失重为2.862 5 mg,与验证结果基本吻合。     

磨粉机磨辊齿型参数与功耗关系研究

通过分析磨粉机在皮磨系统研磨物料粒度与齿型参数的关系,确定邦德理论更适用磨粉机功耗关系研究。将粒径等参数带入邦德公式可知,功耗的影响因素与齿型、物料特性、磨辊速度、辊长、轧距、研磨时间和研磨前后的颗粒粒径有关。以Ⅰ～Ⅰ皮磨系统为研究对象,取轧距分别为0.8、0.6、0.4、0.2 mm,并做适当简化,运用Matlab绘出皮磨系统的功耗与齿深的关系图。由图可知,功耗随着齿辊磨损而逐渐增大。当磨损达到一定程度时,功耗变化急剧增大。由于功耗是评判磨辊是否需要拉丝或更换的重要指标,根据邦德定理从理论角度建立磨粉机功耗数学模型,为进一步研究齿辊磨损寿命与能耗关系提供理论参考。     

基于离散元的辊式磨粉机齿辊功率研究

目的:优化辊式磨粉机I皮磨小麦制粉操作参数,降低制粉能耗。方法:利用EDEM离散元仿真软件,对轧距、喂料量、转速及转速比等关键制粉因素设计Box-Behnken试验,探究操作参数与制粉功率的关系。结果:对齿辊破碎功率影响的显著性排名依次为：转速比、轧距、喂料量、转速比二次项、轧距二次项、轧距和转速比交互、喂料量和转速比交互、轧距和喂料量交互。根据I皮磨粉机出粉要求不同,得到最优参数组合：较细出粉时轧距为0.67 mm、喂料量803.60 kg/(cm·d)、快辊转速537.68 r/min、转速比2.64。较粗出粉时得到低功耗的最佳轧距为0.79 mm、喂料量803.83 kg/(cm·d)、快辊转速576.08 r/min、转速比2.23。结论:仿真模拟结果与实测结果误差在合理范围内,建立的离散元制粉模型可用于小麦制粉时的功率预测。     

信息荟萃

制粉工段向动调节系统据粮油储运科技与经济信息报道，意大利奥克利姆公司开发出了制粉工段的自动调节系统。这个系统能自动遥控磨辊轧距，传感器可以测量磨辊的位置和电机功率。这个系统根据预定的和实际的筛上物数量之间的比率，可对每对磨辊进行距离调节。磨粉机上带有喂料和来自平筛的筛上物流检测装置，此系统连同磨粉机和料流检测装置一起，可将正确的磨辊轧距数据传送到所控制的每一台磨粉机，将实际的筛上物比例准确地维持在面粉生产者用程序设定的数值上，这种自动控制用在第一道皮磨上时是很有好处的，用于后路研磨或重磨通道，位…     

基于机器视觉的鲍鱼风味片残次品在线检测方法

目的:解决鲍鱼风味片在生产过程中出现的边缘残损、内部气孔以及皮料厚度不均匀等外观缺陷自动化检测问题。方法:提出了一种基于机器视觉的在线检测方法。利用机械梳理装置将鲍鱼风味片整理成单层阵列排布;采集图像后,选择图像分割、灰度值拉伸、轮廓边缘提取等方法进行图像处理;利用外轮廓圆形度特征完成边缘残损检测,通过测量皮料厚度完成皮厚异常检测,通过计算气孔面积,完成气孔检测。结果:该在线检测方法对边缘完整度缺陷的检出率为100%,皮厚度异常缺陷检出率为100%,气孔缺陷的检出率为98.65%。结论:该方法具有较好的应用性,能够实现鲍鱼风味片残次品的在线检测。     

磨辊表面温度测量实验及分析

针对布勒MDDK1000/250型和MDDP1000/250型辊式磨粉机1M喷砂辊辊面温度及1B齿辊辊面温度进行了测量,结果显示自磨粉机开始工作时起,辊体内外温差逐渐缩小,后期升温速率加快,渐趋平衡,至76℃达到稳态。MDDK1000/250型磨粉机正常工作时辊面温度比停机时辊面温度高9℃左右,停机状态下1B齿辊辊面测温温度约为51℃,1M喷砂辊辊面停机状态温度约66℃,说明轧距和辊间压力对辊体的温升会有较大影响。测量点温度相差不大,辊体温度基本均匀,磨粉机的等温性能较好。研究结论对辊式磨粉机磨辊轧距的设计以及磨辊内在组织结构是否合理提供了理论依据。     

柑橘全表面色泽在线检测与分级系统

目的:实现柑橘色泽快速、准确分选。方法:建立了一种基于机器视觉的柑橘在线色泽检测与分级系统,系统由上料单元、链式输送机构、图像采集系统和分果单元组成。利用工业相机配合翻滚机构均匀拍摄50~60帧运动中的柑橘图像,获取柑橘完整表面信息。无损检测软件对实时获取的每一帧图像进行预处理,得到二维着色比值,对该比值进行动态跟踪存储,取二维着色比值的算术平均值以降低重复区域对柑橘表面着色率计算的影响,最后对计算的着色率进行判别分级。结果:在6个/s的分级速度下,系统计算的柑橘色泽占比最大误差为5%,分级准确率为90.54%。结论:该系统能够满足柑橘色泽快速、准确的分选需求。     

基于机器视觉的水果分级系统

目的:解决目前水果分级检测方法效率低、误检率高等问题。方法:以苹果为分拣对象,设计一个基于机器视觉的水果分级系统。对实时采集得到的苹果图像进行预处理,使用改进的Canny边缘检测算法进行边缘提取,通过最小外接圆法拟合边缘坐标得到苹果的横切面半径。将采集到的RGB图像转换为HSI图像,根据H分量范围计算红色区域比例,判断苹果的色泽度。统计区域像素点个数,分别求取苹果的面积和周长,计算出苹果的圆形度。结合苹果果径长度、色泽度和圆形度3个特征值对苹果进行综合分级。结果:50个苹果样本试验结果表明,水果分级系统和人工分拣测量的果径误差范围在±1.5 mm以内,样本颜色特征与苹果实际外观相符,圆度值的大小与实际形状优劣相符。结论:该系统满足实际生产中对于苹果分级的需求,有助于实现苹果品级的准确识别。     

高速线材通用孔型系统设计与改进

高速线材原孔型系统主要有Ф5.5,6.0,6.5 mm 3个系列,导致轧制工艺参数不一致,增加轧辊、导卫和轧槽更换次数。通过孔型通用化设计,中轧、预精轧机组9H～17H孔型系统按现高线Ф6.0 mm孔型系列设计;精轧机组18#～26#孔型系统采用轧钢厂现有高线Ф6.0 mm孔型系列,但对26#孔型进行了改进;精轧机组27#～28#孔型系统仍采用轧钢厂现有高线Ф5.5,6.0,6.5 mm孔型系列。采用通用孔型系统对ER70S-6产品Ф5.5 mm规格进行试轧,预精轧、精轧机组料型控制不合理,精轧辊缝值偏小,多个机架辊缝值仅0.2～0.6 mm。对18#～26#孔型进行改进,采用改进后的通用孔型轧制的Ф6.5,8.0 mm HPB235盘条和Ф6.0 mm HRB400螺纹钢筋力学性能均满足GB 1499.2—2007的要求,每年可节约备件费用500万元,提高生产效率。     

基于同色油墨红外光谱的卷烟包装纸真伪鉴别模型

目的:利用卷烟包装上同色油墨的红外光谱差异快速区分卷烟包装纸真伪。方法:分别收集了云烟、玉溪和红塔山3个品牌的真假卷烟包装纸共116个,使用傅里叶变换红外光谱仪(FTIR)衰减全反射(ATR)采集附件采集样品中红色油墨的红外光谱图。对光谱进行二阶导处理后,以光谱范围为3 200~2 700,1 800~1 580,801~720 cm1,56个真品为模型集合,每品牌各20个赝品验证准确性。分别按照品牌区分和不分品牌区分,使用马氏距离判别建立卷烟包装纸真伪鉴别模型。结果:建立了真假卷烟包装纸定性鉴别模型,对云烟、玉溪和红塔山3个品牌的预测准确率为100%,混合模型对随机样品的预测准确率也达到100%。结论:该组模型将同色油墨作为总体样本,预测准确率可达100%,并能大大提高筛查真假卷烟包装纸的工作效率。     

The effect of concentric and aspheric multifocal soft contact lenses on binocular vision in young adult myopes

PurposeMultifocal soft contact lenses (MFCLs) are prescribed to inhibit myopia progression; these include aspheric and concentric designs. The effects of MFCLs on visual quality, accommodation and vergence in young-adult myopes were evaluated.MethodsParticipants were twenty-six myopes (19–25 years, spherical equivalent ?0.50 to ?5.75D), with normal binocular vision and no past myopia control. Pupil sizes were 4.4 ± 0.9 mm during distance viewing and 3.7 ± 0.8 mm at near. In random order, participants wore four MFCLs: Proclear single vision distance, MiSight concentric dual focus (+2.00D), distance center aspheric (Biofinity, +2.50D) (CooperVision lenses), and NaturalVue aspheric (Visioneering Technologies). Testing included visual acuity, contrast sensitivity (Pelli-Robson), stereoacuity, accommodation response, negative and positive relative accommodation, horizontal phorias, horizontal fusional vergence and AC/A ratio, and a visual quality questionnaire.ResultsThe four lenses differed in distance (p = 0.001) and near visual acuity (p = 0.011), and contrast sensitivity (p = 0.001). Compared with the single vision lens, the Biofinity aspheric had the greatest visual impact: 0.19 ± 0.14 logMAR distance acuity reduction, 0.22 ± 0.15 log contrast sensitivity reduction. Near acuity was affected less than distance acuity; the reduction was greatest with the NaturalVue (0.05 ± 0.07 logMAR reduction). The MFCLs altered the autorefraction measure at distance and near (p = 0.001); the accommodation response was less with aspheric lenses. Negative relative accommodation reduced with the aspheric lenses (p = 0.001): by 0.9 ± 0.5D with Biofinity and 0.5 ± 0.7D with NaturalVue. Exophoric shifts were greater with aspheric lenses (1.8 ± 2.4Δ Biofinity, 1.7 ± 1.7Δ NaturalVue) than with the concentric MiSight (0.5 ± 1.3Δ).ConclusionsMFCLs alter visual performance, refraction and vergence; two aspheric lenses had greater effect than a concentric lens.     

基于机器视觉技术的罗非鱼去鳞率无损快速在线检测系统

目的:提高罗非鱼加工质量和效率、提升产品附加值.方法:利用鱼鳞、鱼皮在紫外激发下的荧光响应差异构建基于机器视觉技术的罗非鱼去鳞率快速检测系统. 罗非鱼鱼体图像经预处理、背景分割、ROI区域选取、未去鳞区域快速识别等算法处理后得到未去鳞和去鳞区图像,计算去鳞率并测试系统检测精度.结果:系统的去鳞率检测精度范围为90．18%~94．14%.结论:该系统可实现被测罗非鱼样品的自动输送、检测图像自动触发与采集和图像的快速处理并提高罗非鱼去鳞率检测效率,满足生产线检测要求.     

In vitro power profiles of multifocal simultaneous vision contact lenses

PurposeTo evaluate the power profile of multifocal contact lenses (CLs) using a new technology based on quantitative deflectometry.MethodsThe Nimo TR1504 was used to analyze the power distribution of multifocal CLs. The CLs under study were: Air Optix Aqua Multifocal Low, Medium and High Addition and Focus Progressives. Three lenses of each model were considered.ResultsAll multifocal CLs showed a power profile characterized by a change toward more positive power values when aperture sizes become smaller. The near refractive addition of the lenses under study was +2.61 D, +1.44 D, +1.30 D and +0.30 D for the Focus Progressives, the Air Optix Aqua Multifocal High, Medium Add and Low Add, respectively. The refractive power of the Focus Progressives did not reach the value of the nominal distance power until a radial distance of 0.9 mm from the center of the lens. For the Air Optix Aqua Multifocal Low Add the distance nominal power was reached at a radial distance of 1.5 mm from the center of the lens, whereas this occurred at a distance of 1.8 mm for the Air Optix Aqua Multifocal Medium and High Add.ConclusionThe relation between the pupil diameter of the patients and the power profile of these CLs has a crucial implication on the final distance correction and near addition that these lenses provide to patients. Practitioners should know the power profile of these CLs and measure the pupil diameter of each patient in different situations in order to carry out a customized fitting.     

基于改进SSA优化预测模型的大曲发酵湿度监控系统

目的:解决大曲发酵检测困难、发酵状态难以判断和调控等问题。方法:提出Tent-SSA优化BP神经网络算法大曲发酵湿度预测模型与动态阈值控制算法,实现大曲发酵过程中大曲状态实时判断与调控。结果:该仿真预测模型预测的湿度误差小(0.596%)、鲁棒性强且收敛速度快。结论:基于该模型的大曲监控系统准确可靠。     

Lens parameter changes under in vitro and ex vivo conditions and their effect on the conjunctiva

PurposeTo quantify changes in contact lens parameters induced by lens wear and determine whether these changes are associated with contact lens-induced conjunctival staining (CLICS).MethodsIn vitro: Lens diameter, sag, edge shape, base curve of six contact lens brands (balafilcon, comfilcon, etafilcon, lotrafilcon B, omafilcon and senofilcon) measured at 21 °C and 35 °C (eye temperature). Ex vivo: Diameter of lenses collected from a prospective, randomised, contra-lateral, cross-over clinical trial from 36 subjects wearing all lens types for 1 week daily wear, measured in 35 °C PBS after removal. Ocular surface was examined for lens-induced conjunctival staining by masked examiner.ResultsIn vitro: Changes in diameter and base curve outside ISO tolerance were found with etafilcon A and omafilcon A. Ex vivo: Comfilcon A and etafilcon A had greatest shrinkage in diameter (0.18 mm) and base curve (0.11 mm steeper) with temperature increase from 21 °C to 35 °C. Senofilcon A, lotrafilcon B and balafilcon A maintained most stable parameters between 21 °C and 35 °C. Changes in diameter and base curve from lens wear were not correlated with CLICS (p > 0.49). Multivariate analysis showed significantly greater levels of lens induced staining were associated with lens modulus (p < 0.001) and knife (p < 0.001) and chisel (p < 0.001) edge shapes.ConclusionsParameter changes induced by lens wear were associated with increasing temperature, but these changes in lens diameter and base curve did not induce CLICS. Modulus and edge shape were associated with increased CLICS. The susceptibility of etafilcon A and omafilcon A lenses to parameter changes might be related to their high water content.