共查询到20条相似文献,搜索用时 265 毫秒
1.
何水桥 《自动化与仪器仪表》2013,(5)
介绍了实际生产中对两种混合液共存于同一罐容器体内分界面测量的简单方法。两种液体特点为密度非常接近、在生产中界面以上液体始终充满罐体或处于某一位置之上。基于以上情况和差压变送的基本原理,可以根据差压变送器对容器上下压差的测量值的变化,应用目前自动化先进技术计算出混合介质界面的高度、体积或重量等。在实际运用中大多是采用变送器与分布式控制系统DCS (Distributed Control System)配合完成对界面的间接测量。此法已在我单位进行了大量运用,其特点是测量精度高、对工作环境和被测介质没有太高要求、操作安全方便、易于安装和维护,能有效解决现有技术中介质分界面测量困难的问题。 相似文献
2.
3.
4.
5.
本文阐述了一种利用光电技术检测瓶装精油液位的方法。传感器中的两个发射二极管发出不同高度不同方向的信号,分别经精油液体折射和液面反射后,由两个不同高度光敏三极管分别进行接收,接收到的信号经控制器综合分析后,得出灌装产品液面精度是否合格的结论,以此作为控制灌装系统下一步工位操作的依据。该方法只需调整测量传感器高度就可以实现不同容量灌装瓶的液面测量,一定程度的降低了生产成本,提高了产品的适应性。 相似文献
6.
7.
问 静压式测量液位的原理是什么?如何测量液体密度?
答:容器或贮罐内的液位会对其底部及侧壁产生压力,压力大小是液体密度及高度的函数,当液体的密度不变时,在液体中某一点的压力是单一高度的函数,液位越高对这一点的压力就越大。因此,可以利用差压变送器(或压力变送器)测得液位的高度,见图1。 相似文献
8.
针对固体融化过程中液体与固体之间相变界面的实时跟踪问题,建立了由固定边界上得到的温度和热流到其相变界面轨迹的辨识及跟踪算法。由于在实际过程中无法在液体边测量其温度和热流,因此,该类问题无法通过直接Stefan问题的求解来得到相变界面的实时跟踪。将其归结为一类不适定反Stefan问题的求解,给出了基于Tikhonov正则化方法的滑动区间优化算法。 相似文献
9.
一种分布式原油储罐油水界面监测系统设计 总被引:2,自引:2,他引:0
针对采油厂原油储罐油水界面参数自动化测量的技术需求,在介绍电容法测量液位原理的基础上,给出了一种矩阵式分布的微电容串组结构的油水界面测量仪的设计方法,探讨了测量结果的阵列数据获取界面参数的数据分析方法,并借助RS485通信网络实现了原油储罐油水界面的分布式测量;详细阐述了该分布式测量系统的组成、通信协议和主要程序流程;实际应用结果表明,该系统测量精度可达到≤10cm,工作可靠,可以在生产过程中发挥积极作用。 相似文献
10.
11.
12.
In this paper we extend the results from our earlier work on stable boundary closures for the Schr?dinger equation using the summation-by-parts-simultaneous approximation term (SBP?CSAT) method to include stability and accuracy at nonconforming grid interfaces. Stability at the grid interface is shown by the energy method, and the estimates are generalized to multiple dimensions. The accuracy of the grid interface coupling is investigated using normal mode analysis for operators of 2nd and 4th order formal interior accuracy. We show that full accuracy is retained for the 2nd and 4th order operators. The accuracy results are extended to 6th and 8th order operators by numerical simulations, in which case two orders of accuracy is gained with respect to the lower order approximation close to the interface. 相似文献
13.
14.
在手机报警受限的情况下,为了使求助者能向校园保卫处紧急报警并且准确定好自己所处的位置,本文研制了求助者随身携带的微型无线遥控器和相应的配套系统。当求助者按下紧急求助按钮时,立即向保卫处发出求助信号,同时在保卫处的监控界面上直观显示求助者所在的位置。测试表明,从求助者按下紧急求助按钮到保卫处页面刷新显示为40~50s,位置精度为20~40m。 相似文献
15.
为改善基于力信息的人机协调运动中人机交互力,采用了在人机接口中设置弹性元件的方法,建立了具有柔性人机接口的人机交互力学模型。在已有鲁棒自适应阻抗控制方法的基础上进行改进,提出了一种基于柔性人机接口的自适应阻抗控制方法。此控制方法是对阻抗外环位置速度进行比例补偿,对力控制内环采用模糊PID (proportion integral differential)控制,实现改进自适应阻抗算法,从而提高了位置跟随精度,并有效减小了人机交互力。分析了人机接口中弹性元件对控制效果的影响,获得了不同刚度系数时,交互力控制效果和位置跟随精度。在此基础上,建立了试验系统,完成了试验。人机协调运动试验结果显示:应用柔性人机接口和改进后的控制方法具有更好的人机交互力控制效果。标准运动输入试验结果显示:改进后的控制方法具有更好的人机交互力控制效果和更高的位置跟随精度;人机交互力大小、位置跟踪准确性与人机接口刚度系数大小均成正比。 相似文献
16.
Among the successful approaches for treating multiphase problems involving an interface, the continuous-interface method often handles the surface force via a locally integrated body force formulation. On the other hand, the sharp-interface method treats each phase separately while coordinating them via an explicit interface treatment. The sharp interface method computationally more demanding, but the continuous interface method can create spurious velocity in the interface region, which compromises the solution accuracy. Furthermore, the large property jumps often observed between liquid and vapor phases can influence the numerical accuracy, and needs to be investigated. In order to quantitatively demonstrate the relative performance of the sharp- and continuous-interface methods, we have considered a spherical drop in static equilibrium to highlight the role of the interface treatment. It is shown that the sharp-interface method is second-order accurate while the continuous-interface method is first-order. Furthermore, the sharp interface method is insensitive to the property jumps. 相似文献
17.
With the changes in the interface paradigm, a user may not be satisfied using only a behavior-based interface such as a mouse and keyboard. In this paper, we propose a real-time user interface with emotion recognition that depends on the need for skill development to support a change in the interface paradigm to one that is more human centered. The proposed emotion recognition technology may provide services to meet the need to recognize emotions when using contents. Until now, most studies on an emotion recognition interface have used a single signal, which was difficult to apply because of low accuracy. In this study, we developed a complex biological signal emotion recognition system that blends the ratio of an ECG for the autonomic nervous system and the relative power value of an EEG (theta, alpha, beta, and gamma) to improve the low accuracy. The system creates a data map that stores user-specific probabilities to recognize six kinds of feelings (amusement, fear, sadness, joy, anger, and disgust). It updates the weights to improve the accuracy of the emotion corresponding to the brain waves of each channel. In addition, we compared the results of the complex biological signal data set and EEG data set to verify the accuracy of the complex biological signal, and found that the accuracy had increased by 35.78%. The proposed system will be utilized as an interface for controlling a game and smart space for a user with high accuracy. 相似文献
18.
目前的人机交互界面视觉显著度评估方法准确性差、能耗高,提出基于人眼视觉的多媒体人机交互界面视觉显著度评估方法。采用自适应高斯滤波器对人机交互界面进行滤波,通过Guassian函数将界面图像梯度方向转换成水平与垂直两个方向的导数,确定界面梯度方向大小,据此得到校正后的交互界面图像。利用Drago对数算子对校正后的交互界面色调进行调整,根据交互界面亮度与场景亮度之间的映射关系,得到界面像素值的亮度值压缩度可见细节程度,获取色调和亮度调整后的交互界面图像。依据界面图像视觉显著度的共现不同理念,将人眼视觉显著度影响指标进行量化,得到交互界面空间位置函数。设置交互界面各个图像块内方向种类数量和边缘点数量,获取界面各子图像中某像素点的纹理复杂度函数。给出加权系数,将界面空间位置函数和像素点的纹理复杂度函数作为评估指标进行加权输出,给出交互界面视觉显著度评估结果。实验结果表明,上述方法平均评估能耗为59.4nJ/bit,评估准确率高。 相似文献
19.
为了满足高速信号数据采集与存储的准确性及数据的实时分析需求,该系统支持多接口的高速数据采集与转储功能。通过多接口转储数据对比,保证数据准确性。通过光电转换板实时透传保证数据可实时分析。经测试,可实现基于高速Aurora接口的1.25 Gbps数据采集速度,基于网口的70 Mbps的数据转储速度,以及基于光口的625 Mbps数据转储速度和基于光口的1.2 Gbps数据透传速度。 相似文献
20.
This study investigated the effects of age group, interface type, and key area on accuracy, usability, the change of critical fusion frequency, and subjective visual fatigue in Taiko no Tatsujin game playing. Four groups divided by age (young adult, adult, middle‐aged adult, and senior citizen), two types of interface (solid and touch), and two types of key areas (approximately 1.1 and 0.6 cm2) were investigated in the experiment. The results showed significant differences for age group on accuracy, especially for young adults and senior citizens. The solid interface demonstrated better accuracy and usability and less subjective visual fatigue than the touch interface. The approximately 1.1 cm2 key indicated better performance than the 0.6 cm2 key in all indexes. It is inferred that the solid interface with the 1.1 cm2 key had better performance. Therefore, mobile phones with a larger key area are more suitable for game playing. 相似文献