A knowledge-based system for sensor interaction and real-time component control

This paper outlines the integration of a two-dimensional vision system with a pneumatic proximity-to-tactile sensing device to form a Co-ordinated ‘Hand-Eye’ system. With the aid of a knowledge base this system is utilised as an intelligent condition monitoring tool for recognition and detection of orientation of parts in a flexible manufacturing environment. An expert system is formulated to interrogate the acquired data streams for the purpose of comparative studies with the knowledge base. Appropriate data processing methods are employed to ensure rapid manipulation of data for real-time applications.     

基于多阶通道响应对称双线性卷积神经网络的 分布式压力识别

目前基于传感阵列的分布式压力识别方法,通常先将压力信息表征为图像,然后再进行特征的提取与分类,但存在两个问题：传感阵列密度有限,压力图像分辨率低;柔性传感阵列存在弹性耦合,压力图像边缘模糊。本文提出了一种多阶通道响应对称双线性卷积神经网络(HoSB-CNN)。首先,构建通道注意力响应CNN,通过给不同特征依照显著性赋权值以提升一阶特征的描述能力。其次提出对称双线性特征,引入二阶特性提高CNN对边缘和纹理的敏感度,并利用其结构对称性降低网络复杂度。最后,提出多阶特征混合策略提升网络的非线性拟合能力。此外,通过自制数据采集平台和8×8传感阵列,建立压力字母数据集用于HoSB-CNN的验证。结果表明,该算法获得了98.11%的准确率。     

Process Planning Using Adjacency-Based Feature Extraction

The use of attributed adjacency (AA) feature recognition can encapsulate the engineering significance of a part and represent it as a matrix or an arc-node graph. This creates a feature recognition technique that involves scanning a matrix or graph for a combination of zeros (concave relationships/edges) and ones (convex), or smaller arc-node graphs that are predetermined to be features. AA techniques have often suffered problems when dealing with feature interactions, as a feature found must be exactly matched with those stored. This paper presents a modification of the AA matrix and employs a new concept for identifying features and the application in developing software for process planning. A unique feature taxonomy is described, which when combined with the new feature identification system creates a feature recognition and extraction system that includes curved surfaces and eliminates the need for separating interacting primitive features. The new system takes its input from neutral STEP files and produces a list of features with complete information for process planning. cycle, and so automatic feature recognition has its place in manufacturing. ID="A1"Correspondance and offprint requests to: R. Ibrahim, Faculty of Engineering, Monash University, Caulfield Campus, 900 Dandenong Road, Caulfield East, 3145 Victoria, Australia. E-mail: raafat. ibrahim@eng.monash.edu.au     

An attitude sensing device

A device for sensing the attitude of an arbitrarily located object has been developed by the Polar Geophysical Institute, Kola Research Center, Russian Academy of Sciences, for carrying out geophysical research. The device is capable of determining three angular coordinates of an object: the angles of roll and pitch with respect to the Earth’s horizontal plane and the azimuth angle with respect to the direction toward the magnetic north. The measurement range of the azimuth is from −180° to 180° with an error of ≤1°. The angles of roll and pitch can be measured in the range from −60° to 60° with an error of ≤0.5°. The device is reliable and easy to operate.     

一种新颖的光纤微弯压力传感器

利用微弯探头和具有硬中心的小位移平膜片设计而成的光纤微弯压力传感器,可用于测量气体或液体的压力。本文阐述了传感器的结构及其传感机理。该光纤微弯压力传感器能够组成分布式光纤测试系统,具有机械调零、过载保护功能。     

Dual Material Rapid Prototyping Techniques for the Development of Biomedical Devices. Part 1: Space Creation

Polymeric drug delivery devices play an important role in drug administration. However, the current polymeric drug delivery device fabrication methods lack precision. This impairs the quality of the devices, resulting in a decrease in the efficiency and effectiveness of drug delivery. The concept of building parts layer by layer out of powdered raw materials makes selective laser sintering (SLS) a suitable process for fabricating polymeric matrix drug delivery devices. The current SLS process is not capable of processing two or more materials separately. This work explores the possibilities of SLS per-forming a dual material operation by developing two process models. These two processes can then be integrated to form a dual or expanded multimaterial fabrication technique and act as a foundation for future work in multimaterial applications such as polymeric drug delivery device fabrication. Accord-ingly, two papers are presented. In this paper, Part 1, the focus is on the first process, which is a "space" creation technique in which a "space" is created by varying the density of a first representative material using heat during sintering. Three methods – one based on a vacuum and a place method, and the other two based on two variations of a laser compacting method – were tested. Results have shown that by varying the laser power during sintering, it is possible to create channels in which a second material can be deposited.     

人体感应技术在智能电力机器人设计中的应用

为使机器人运作更灵活、功能更完善,提出在智能电力机器人设计方案中应用人体感应技术。以多光谱自动目标识别技术为基础,将 8 引脚芯片与部分外接元器件结合,组装人体感应装置。 采用全球定位系统与直接数字化 X 射线摄影导航系统,分别依据观测信号传播时间与起点坐标位置和方位角,实现机器人导航与航向控制功能。 在 1 个机器人上安装至少 2 个感应装置,针对形成的感应区域,定义装置基本功能,就不同电力应用场景,建立预警机制与躲避机制。 电力现场实际操作结果表明,设计的感应装置安全预警性能与物体躲避性能比较理想,加强了电力机器人的实用性,使其具备在其他领域中得以广泛应用的潜力与条件。     

金属罐体自动焊机径向自动跟踪装置设计

本装置利用物体重力,使自动焊机机头在垂直方向能随工件表面的起伏而位移,并使体表面保持固定距离,从而保证了焊接质量.本文研究了金属容器的焊接原理和方法,针对容器几何尺寸较大,难于手工焊接的情况,提出了用埋弧焊自动焊机代替手工焊的方案.通过进一步研究埋孤焊工艺要求和工件结构特点,设计了自动跟踪装置,其使焊枪和送料管与工件表面保持固定高度,并配有气压系统辅助,以保证该装置的可靠性与可调性.通过样机的试机,证明该方案能满足加工要求,安全可靠、设计合理.     

Flow velocity estimation using a fish-shaped lateral line probe with product-moment correlation features and a neural network

Environmental studies on fish require measurements of highly turbulent flows in both the laboratory and in the field. A fish-shaped bioinspired flow measuring device is applied in conjunction with data processing workflow which leverages the interactions between the body and the surrounding flow field for velocity estimation in turbulent flows. Our objective is to develop a robust velocity estimation methodology relevant for studies of fish behavior using a bioinspired fish-shaped artificial lateral line probe (LLP). We show that the device is capable of covering the range of flow velocities from 0 to 1.5 m/s. Three different sets of experiments performed in a closed flow tunnel, a model vertical slot fishway and laboratory open channel flume were collected and combined to provide time-averaged flow velocity and LLP measurements under fully turbulent flow conditions. Based on the experimental results, a signal processing workflow using Pearson product-moment correlation coefficient (PCC) features in conjunction with an artificial neural network (ANN) is presented. Using PCC features provides a simple data fusion methodology exploiting the use of the LLP's as a simultaneous collocated sensing array. In this work we show that (1) the PCC-ANN workflow provides the first LLP velocity estimator without repeated calibration across the full span of 0–1.5 m/s, (2) using all pressure sensors results in the best performance with R²=0.917, but requires a PCC feature matrix of 55 dimensions and (3) a stepwise reduction of the PCC feature matrix allows for the use of as few as 11 dimensions, and results in R²=0.911, indicating that a modest reduction in LLP velocity estimation performance can be gained by a large reduction in dimensionality. A surprising finding was that after stepwise reduction, the best performing sensor pair combinations were not the expected pitot-like anteroposterior couples spanning from nose to body. Instead, it was found that optimal velocity estimation using the LLP exploited a network of sensor pairs. It is shown that the LLP can be implemented similar to an ADV for highly turbulent flows over the range of 0–1.5 m/s, and in addition provides body-centric pressure distributions which may aid in the interpretation of fish hydrodynamic preferences in future environmental studies.     

基于吉林一号遥感图像的星载目标快速识别系统

针对传统遥感图像地面目标识别系统图像获取周期长,信息实时性差等问题,设计星载目标快速识别系统,用于卫星在轨快速识别,提出改进的基于快速视网膜关键点(FREAK)的特征匹配识别算法,解决遥感图像数据量大、背景复杂的问题。介绍了星载目标快速识别系统的工作原理,提出简化的FREAK特征提取模型,将原有算法的七层模型减少为四层,用于快速提取出遥感图像中目标特征;利用二进制量化空间将高维特征数据量化为二维数据,提高算法的准确度;最后通过匹配,快速识别出遥感目标。实验结果表明,识别算法的准确度平均提高2.3%,识别用时缩短约27.8%,满足遥感卫星在轨目标快速识别的要求。     

Obtaining four-dimensional vibration information for vibrating surfaces with a Kinect sensor

In this paper, we present a real-time approach to obtain four-dimensional (4D) information from the surfaces of low-frequency vibrating rigid objects using a Kinect sensor. This consumer-grade range sensing technology is used for markerless tracking on the three-dimensional (3D) coordinate points of object surfaces. The time coordinates are simultaneously defined by the sampling interval converted from the frame rate of 30 frames per second (fps). Then the 4D (defined in the space time) vibration information can be recorded in the form of (x, y, z, t), enabling researchers to investigate the dynamic features of object surfaces efficiently. A comparison of the measurement accuracy and efficiency of a Kinect sensor, a stereo vision system and a contact sensor is carried out. The results confirm the superiority of our approach in efficient measurement and demonstrate that the contrastive amplitude error ranges within 0.6 mm when the frequency is not beyond 15 Hz.     

Wet STEM: a new development in environmental SEM for imaging nano-objects included in a liquid phase

Environmental scanning electron microscopy (ESEM) enables wet samples to be observed without potentially damaging sample preparation through the use of partial water vapour pressure in the microscope specimen chamber. However, in the case of latices in colloidal state or microorganisms, samples are not only wet, but made of objects totally submerged in a liquid phase. In this case, under classical ESEM imaging conditions only the top surface of the liquid is imaged, with poor contrast, and possible drifting of objects. The present paper describes experiments using a powerful new Scanning Transmission Electron Microscopy (STEM) imaging system, that allows transmission observations of wet samples in an ESEM. A special device, designed to observe all sorts of objects submerged in a liquid under annular dark-field imaging conditions, is described. Specific features of the device enable to avoid drifting of floating objects which occurs in the case of a large amount of water, thus allowing slow-scan high-definition imaging of particles with a diameter down to few tens of nm. The large potential applications of this new technique are then illustrated, including the imaging of different nano-objects in water. The particular case of grafted latex particles is discussed, showing that it is possible to observe details on their surface when submerged in water. All the examples demonstrate that images acquired in wet STEM mode show particularly good resolution and contrast, without adding enhancing contrast objects, and without staining.     

Backward-motion control of a mobile robot with n passive off-hooked trailers

A passive multiple-trailer system provides various practical advantages for multi-functional service robots. However, motion control is difficult because the kinematic model is highly nonlinear. The kinematic design of a trailer system was proposed in prior research of ours. In this paper, it is shown how the backward motion of a robot with n passive trailers can be controlled. Once the desired trajectory of the last trailer is computed, the control input of the pushing robot is obtained through the proposed control scheme. Some experimental issues on reversing the trailer system are addressed. This paper provides an answer to the following question: “Does the system work well even if there are sensing or modeling errors?” Although it is difficult to obtain general analytic solutions for the above research question, a practical answer will be explored though simplified analysis and experiments. Experimental verifications are carried out using a mobile robot with three passive trailers. The experimental results show that backward-motion control can be successfully carried out by applying the proposed control scheme.     

A portable fluorescence detector for fast ultra trace detection of explosive vapors

This paper developed a portable detector based on a specific material-based fluorescent sensing film for an ultra trace detection of explosives, such as 2,4,6-trinitrotoluene (TNT) or its derivate 2,4-dinitrotoluene (DNT), in ambient air or on objects tainted by explosives. The fluorescent sensing films are based on single-layer chemistry and the signal amplification effect of conjugated polymers, which exhibited higher sensitivity and shorter response time to TNT or DNT at their vapor pressures. Due to application of the light emitting diode and the solid state photomultiplier and the cross-correlation-based circuit design technology, the device has the advantages of low-power, low-cost, small size, and an improved signal to noise ratio. The results of the experiments showed that the detector can real-time detect and identify of explosive vapors at extremely low levels; it is suitable for the identification of suspect luggage, forensic analyses, or battlefields clearing.     

Effect of dispersion compensation on FBG sensing systems’ performance

This paper introduces the use of a fiber-optic communication system for interrogation and transmission of data from fiber Bragg grating (FBG) sensors. Signal coding and dispersion compensation methods, usually used in communication systems, are used to improve the sensing system’s performance. Moreover, communication system parameters are used to assess the improvement in the FBG sensing performance. This is done through the determination of the profiles of Q-factor and eye diagrams. The sensors considered in the simulations are strain sensors subjected to a wide range of strains. The results obtained show a clear improvement of the sensing system with symmetrical compensation. The proposed method is suitable for applications where fiber-optic links are available near both the sensing location and information-collection and-processing unit, even if these two are hundreds of kilometers apart. A good example of where such a system can be applied is the oil industry. The rigs are usually very far from headquarters, but both might be close to a fiber node. Published in Russian in Pribory i Tekhnika Eksperimenta, 2006, No. 3, pp. 115–118. This text was submitted by the authors in English.     

一种飞机模拟驾驶力反馈设备的设计与实现

飞机模拟驾驶杆是飞行模拟器的重要组成部分,是向飞行员提供操纵力的人感系统。设计了一种新的阻抗型力觉交互设备,仿真飞机驾驶杆的操纵力,提出了弹簧-电动机的力控制方案。设备通过弹簧的变形为操作者提供反馈力,通过电动机做位置伺服控制弹簧的变形量改变设备的刚度,从而调整操纵力的大小。以一自由度的样机为平台建立了人机交互系统,进行了力觉交互实验,验证了力控制方案和传动方案的可行性。     

基于IPC和模糊控制技术的热电厂锅炉温度测控系统

针对小型电厂锅炉温度与相关的流量、液位、压力等测控对象的工艺特点，研究采用工控机与模糊控制技术，构成具有自动测控锅炉温度、流量、液位、压力的控制系统。有效保征了电厂锅炉发电、供热、供汽的工艺要求，提高了锅炉测控温度以及流量、液位、压力的精度。该系统硬件、软件配置简单，操作方便，适用小型电厂锅炉温度及其它指标控制场合。     

Continuous accurate pH measurements of human GI tract using a digital pH-ISFET sensor inside a wireless capsule

This paper describes the design and implementation of a reliable, low-power pH-ISFET sensor inside a wireless diagnostic capsule for monitoring the pH of the human gastrointestinal (GI) tract. The sensitive element of the pH sensing device was an ion-sensitive FET (ISFET) with a threshold voltage that varies by concentration of hydrogen ions. An Ag/AgCl reference electrode that was surrounded by gel (mixed KCl) was applied in this pH-sensing device. An application-specific integrated circuit (ASIC) that is designed by a very large scale integration (VLSI) architecture was used as the interface between the pH sensing device and a wireless transceiver. Experimental results demonstrated that the pH sensitivity and operating range of the pH sensing device was 44.94 mV/pH and 1–11 pH; the device is linear. With the 18-bit Analog/Digital converter (ADC) module in the ASIC, the resolution could achieve 11,780 bits/pH. Moreover, the power dissipation of the pH-sensing device was only 0.048 mW while working in intermittent mode (duty cycle = 20%). Results from human experiments showed that this pH sensing device can work reliably for 136 h, and the pH data of sampled from the human GI tract can be received by a portable data recorder outside the human body in real time.     

双光纤光栅双参量传感系统优化设计与研究

运用矩阵范数理论对所建立的双光纤布拉格光栅（FBG）压力与温度传感系统系数矩阵的态性进行了研究。结果表明，传感器对压力与温度测量误差传递的稳定性主要取决于对压力与温度传感绝对灵敏度的配系，即与系数矩阵条件数大小有关。优化设计双参量传感系统的目标就是通过破坏系数矩阵中行间和列间各元素的近似线性相关性及减小各元素之间的比例，来减小系数矩阵的条件数。通过对金属机敏元件作为衬底的双光栅双参量传感器对压力与温度传感的绝对灵敏度的优选，将其压力与温度传感系统的系数矩阵条件数降为4．4，由此得到双FBG对压力与温度双参量测量的传递误差分别为0．68％和1．1％。     

局部方向模式在非接触掌纹识别中的应用

提高非接触掌纹识别系统的性能是目前掌纹识别领域一个具有实际意义的热点。针对非接触掌纹识别系统的鲁棒性问题,以掌纹图像的纹理特征为基础,提出一种基于局部方向模式(LDP)的掌纹识别方法,设计并实现了符合应用环境的嵌入式系统。LDP方法主要利用了Kirsch八方向算子的边缘响应值,从而获取图像的纹理方向模式特征。首先给出LDP算法的基本模型和流程,然后将非接触掌纹图像分成大小均匀的区块,利用LDP算法获取不同区块的纹理特征直方图向量,并进行融合形成总的模式特征,最后使用Chi距离测度进行匹配识别。在香港科技大学(HKUST)和自建的非接触掌纹图库上进行了实验测试,结果表明,该方法正确识别率可达97.824 4%和96.754 7%,相比其他典型和流行方法,最高可提升6.452 9%和5.995 6%。同时在室内环境下,利用自行设计的嵌入式原型装置进行了初步实际测试,结果表明,该方法正确识别率可达96.193 3%,具有可行性和有效性,提高了非接触掌纹识别系统的性能。