共查询到20条相似文献，搜索用时 15 毫秒
1.
The geometrical model of profile error is put forward to describe the tooth surface precision of hypoid gears. The influence of each machine tool setting error on profile error is investigated respectively, and the research of the associativity and compensativity among the machine tool errors are made. The setting errors of machine tool, the optimal modifying parameters and their value are got from the measurement coordinates of hypoid gear real tooth surface, and the adjusted manufacturing shows the geometrical precision of the tooth surface is improved effectively. 相似文献
2.
On the basis of studying the accurately identification algorithm of planar target and transformation model of the space vector, the imaging target models and spatial attitude measurement models are established. Then, a new topological positioning method is put forward. Finally, the four-wheel location measurement is given as an example. The results demonstrate that the method has better anti-interference and higher measurement precision, which provides a feasible method for a machine vision measurement system by using the plane target. 相似文献
3.
Application of Error Compensation Methods in High Precision Machining of Globoid Worm 总被引：5，自引：0，他引：5
鲜食葡萄始终占主导地位是我国葡萄产业发展的一个突出特点.长期以来,我国鲜食葡萄贮运保鲜业一直比较滞后,基本是季产季销,地产地销.因此,我国鲜食葡萄集中产区经常出现采后"运不出、贮不进、销不掉"的被动局面,阻碍了鲜食葡萄产业在适宜栽植区的快速发展.一些非适宜产区为了填补当地鲜食葡萄市场空白,也在积极发展鲜食葡萄生产,其结果必然导致生产成本提高,不利于我国鲜食葡萄的区域化种植和商品化生产基地的建设. 相似文献
4.
Aiming at the low efficiency and precision of hot rail steel surface faults detecting at present,a suit of surface defect detection system of hot heavy rail based on the machine vision is put forward. Multi-CCD cameras are used to collect pictures. According to the geometric characteristics of the heavy rail and its defect characteristics of high-frequency region,six angle shot is used for heavy rail,and then various image processing technology are adopted in workstation. The system adopts improved Hough transform to get surface faults and Kohonen network to make a classification for the characteristics of low SVM training algorithm. The above key machine vision technology for detection of hot heavy rail surface defects greatly improves the speed and accuracy of testing and the detecting correct rate arrives over 85%. 相似文献
5.
Based on coordinate measrement of tooth surface of ZC1 worm, the deviation function for evaluating tooth surface is established. According to minimal zone principle, the profility of tooth surface of worm is evaluated. The machining errors of the worm are divided into setting error and adjusting error of the machine and tool. By error compensation, the setting error and adjusting error are corrected and the manufacturing precision of the worm is improved. 相似文献
6.
Ronald V. Kalafsky 《Growth and change》2016,47(2):138-156
Examining and comparing a country's machine tool industry often can be used to gauge its quality, productivity, and innovation in manufacturing as a whole. It can also indicate wider trends in global manufacturing. This paper, accordingly, examines changes in the global machine tool industry since 1990 in terms of several metrics, including production, industrial concentration, exports, and lastly, firm‐level leadership patterns. A broad framework entailing evolutionary economic geography, specifically, path dependence, and global production networks, informs this research. Several noteworthy patterns emerge from the data, including the sustained dominance of a select number of national machine tool industries; several former manufacturing powers in decline; and the emergence of a few national machine tool producers, notably China. The article concludes with a discussion of these changes, possible implications for manufacturing at large, and avenues for future research. 相似文献
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8.
Yu Honglin 《保鲜与加工》1991,(1):104-107
The desing principle and the manufacturing method relevant to the high precision many kind of code radial gratings are discussed in this paper. It is helpful to the pratical use for improving the manufacturing precision and surface quality of metrological radial gratings. 相似文献
9.
It is difficult to measure the geometric quantity of small parts in finishing, assembling and measuring, because it's easy to break the workpieces' surface and alter their position by means of traditional contact measuring methods.There are some non contact measurers, such as,light feeler pin and interference microscope etc., because of it's high price and strict working conditions,so it's difficult to promote them in widely use. Precision measurement system based on machine vision has the advantages of non contact measuring as well as high performance and low price. Some problems, such as light source, algorithm of edge fitting, auto focusing,are discussed. 相似文献
10.
为探究水稻冠层外观特征与水稻氮素营养状况的关系,综述了应用计算机视觉技术进行水稻氮素营养诊断的基本思路及研究进展。主要分述了常规性水稻氮素营养指标的获取,水稻冠层图像的获取、预处理以及特征的提取与优化,水稻氮素营养诊断模型建立的方法等方面的内容。指出近地面水稻冠层图像的获取方法、水稻图像处理方法、多种综合性特征的优化选择方式都有待进一步研究,应用机器学习进行水稻氮素营养诊断建模的方法需要更加深入探究。今后应加大计算机视觉技术在水稻氮素营养诊断相关研究中的应用,将多种图像处理方法、特征优化选择方法与机器学习建模方法相结合,并探寻更为简便易行的方法进行水稻氮素营养诊断。 相似文献
11.
Lei Jiyao Zhang Sifu He Shide 《保鲜与加工》1988,(2)
This paper describes the research work of analyzing vibration signal to monitor and diagnose on line the ball bearing fatique. Carrying out a large mumber of life test on ball bearing test machine, it is discovered that in the so called "second effect" vibration signal as the bearing fatique occurs, apart from the two widely used spetrum charactersof "fraverse frequency" and "high frequency shock pulse" , there is another important but rarely known opcctrum characteristic of high frequency peaks existing in the middle-to-high frequency band.The generating mechanism, effect factors and test method of those high frequency peaks are researched tentativ tentatively. Two binds of device for monitoring abnd diagnos sing ball learing fatique on line are developed based ion this new type spectrum characteristic. One consists of a bandpass filter, the other is based on the spetrum characters which corns from the DDS ( Dynamic Data System ) modeling 相似文献
12.
Qin Datong Zhang Guanghui 《保鲜与加工》1993,(1):7-13
A method of modifying the double enveloping worm gearing with developable tooth surface has been proposed to reduce the sensibility of the worm gearing to the manufacturing errors. The tooth contact and kinematic precision of the modified worm gearing with manufacturing errors has been investigated by the TCA method. The results show that by the modification, the edge contact resulting from the manufacturing errors is avoided or effectively relieved,and the kinematic error of the worm gearing is obviously reduced. 相似文献
13.
提出了基于灰度-梯度共生矩阵结合机器视觉技术检测大米加工精度的方法。使用实验碾米机制备不同加工精度的大米样品,设计大米加工精度机器视觉检测系统获取不同加工精度大米样品图像,再利用灰度-梯度共生矩阵提取大米图像的纹理特征,采用逐步判别分析法构建Fisher判别函数组对大米样品的加工精度进行检测。试验结果表明:该方法对4种不同加工精度大米样品检测的平均准确率达到94.00%。 相似文献
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In recent years , because of increasing mobile users ,the wireless location and business is the most attractive business in the world , accurate location information to users has become one of criterion business for mobile communication ,so a discussed deeply wireless location technology is very value. This paper discusses it from high accuracy algorithm for wireless location on the network , by the emulation and comparison, it has shown that there are different algorithms in different surroundings for arriving at satisfied precision 相似文献
16.
用机器视觉技术获取棉花叶片叶绿素浓度 总被引：28，自引：3，他引：28
运用机器视觉技术获取棉花叶片颜色特征，建立棉花叶片叶绿素测定模型。研究表明，（1）RGB颜色系统的B/R、色度坐标b、b/r值及HIS彩色系统中的饱和度S值均与棉叶叶绿素含量显著或极显著相关，可用于测定叶片叶绿素浓度；（2）棉花叶片正、背面RGB、HIS颜色系统的颜色特征值与叶绿素浓度的相关性高度一致，且叶片背面的颜色特征值与叶绿素浓度之间的相关性更高；（3）基于机器视觉技术建立和筛选出了6组棉叶叶绿素含量预测模型，预测误差在7.8%~13.65%之间。为棉花生长的快速监测提供了依据。 相似文献
17.
Xiao Dichen Liang Xuehang Zhang Jisheng 《保鲜与加工》1990,(5):7-14
A method which uses computer to model the form cutting of helical is presented and quantitatively analysed the errors of the ptofile shape and its position from the deviations of manufacturing and installing of the forming cutter and helical movement of the machine tools are quantitatively analysed, the optimum technique is used to revise the adjustable parameters for compensating the error. It is valuable in engineering application. 相似文献
18.
Crystals with high stability are generally adopted as benchmark in the measurement of signal's actual frequency and stability, but the requirement of high precision can not be met. Some researchers found out improved methods, but it resulted in high costs. We introduce a new method, in which we use the second pulse creating from Global Position System as benchmark and design corresponding circuits in High Density Programmable Logic Devices(HDPLD), after that, we observe the resulting signals on oscilloscope. The pulse from Global Position System is easy to get and the whole system is very cheap. As the Global Position System is based on atomic clock which is accurate and stable, the measuring precision is improved greatly. 相似文献
19.
在"双一流"大学建设的时代背景下,以人才培养为核心的高校教育工作是当前高校的工作重心之一。为此,借鉴一些新的人才培养模式是更好地建设"双一流"大学的重要途径之一。IFT国际本科认证课程项目是目前国际上具有较高影响力的食品行业认证课程项目。简要介绍了该课程认证项目,并讨论其对高校本科教学中思维方式、课程改革理念、课程设置理念、学生能力培养等几个方面的启示,旨在为更好地培养"三创""三有"人才提供一些参考依据。 相似文献
20.
Chou Yongjin Tang Luping 《保鲜与加工》1988,(4)
This paper introduces a controlled temperature system in which the silicon controlled rectifier is controlled by a TP-801 microcomputer. A common-used PID expression is usually applied to control temperature, but it is necessary to adjust three parameters, making the operation quite inconvenient. This system adopts the measurement of a simplified expanded-critical proportion, only one parameter is necessarily adjusted. In addition, the method of digital triggering is applied so that the D/A transfer and silicon adjuster are omitted, thus decreasing the cost and increasing the reliability of operation. This system has higher precision of control and better degree of linearity of temperature increment or decrement. 相似文献