Actual Equipment Research Articles

Scale adaptive subdomain matching network for bearing fault diagnosis

The wide application of transfer learning technology can effectively solve the problem of the difference between data collection and actual application equipment of traditional intelligent fault diagnosis methods in the practical application process. However, the difference in subdomain space and the serious imbalance of data samples in the process of simultaneous transfer restricts the deep transfer learning technology to the engineering application of high-precision diagnosis. In order to solve the problem of subdomain matching with different subspaces and unbalanced data samples, in this paper we study the subdomain adaptive method and propose a scale adaptive subdomain matching (SASM) method. The SASM method divides the global feature space according to the sample labels, and features with the same label will be divided into the same sub-feature space. Using the edge distribution of the sample and the category weight of the label, the SASM method can effectively optimize the feature distribution of the same subdomain and the weight distribution of different subdomains. Based on the establishment of a clearer internal structure of features, the field adaptation effect is improved, and the matching ability is enhanced when the sample is unevenly distributed. At the same time, the SASM network (SASMN) method for unsupervised bearing fault diagnosis is constructed and validated by experiments. The results indicate that SASMN can effectively optimize the subdomain adaptive effect, and the diagnostic accuracy of the target domain data set is significantly higher than the other three currently popular domain adaptive fault diagnosis methods.

Mechanized spreading of ceramic powder layers for additive manufacturing characterized by transmission x-ray imaging: Influence of powder feedstock and spreading parameters on powder layer density

Spreading of uniform, dense powder layers is a critical requirement for powder bed additive manufacturing (AM) processes, and layer quality is influenced by powder feedstock selection and spreading parameters. In prior work, quantification of powder layer density has required disruption of the powder layer after spreading, or compromise in the precision and/or design of the spreading mechanism compared to actual AM equipment. This work demonstrates the use of a precision, mechanized powder spreading testbed coupled with transmission x-ray imaging for spatially-resolved, non-contact powder layer density measurements. Specifically, the influence of several variables on the spreading of aluminum oxide powders is studied: powder size and shape, spreading tool choice (i.e., blade versus roller), traverse speed and/or rotation rate, and powder dispensing methodology (i.e., piston-fed vs hopper). For coarse powders, the density of layers spread with a roller geometry outperforms a blade geometry, reaching the tapped density for the coarse spherical powder. In addition, spreading with roller counter-rotation increases layer density for fine powders but decreases layer density for coarse powders. Increasing traverse speed or the use of textured rollers results in reduced powder layer density for fine powders. Finally, for fine powders, deposition with a vibrating hopper dispenser instead of a piston-fed mechanism, coupled with spreading by a counter-rotating roller, gives spread layer density equal to the tapped density.

Approaches for Motion Control Interface and Tele-Operated Overhead Crane Handling Tasks

This study aimed to identify the effects of different approaches to a motion control interface (MCI) in tele-operated crane handling tasks. In this study, due to the difficulty of applying the actual equipment to the experiment, we presented a prototype system of a tele-operated overhead handling (TOH) crane. Specifically, we investigated participants’ task performance including the accuracy of task completion during unloading, heart rate variation, workload, and the relationships between these factors when four motion control approaches were used: pointing (P), keyboard (K), orientation (O), hand-free gesture (HG). Experiments were conducted with two groups of participants: 21 university students and 11 crane operators used each of the four control methods. A task condition for handling iron blocks was tested. The efficacy of each motion control approach for task performance was evaluated by a within-subject experiment with a novice group. The expert group was used for comparing the task performance and satisfaction in the prototype system with the novices, evaluating whether the prototype system was reproducible for a real setting in the construction site. The results showed that the task completion time, the weight of physical demand, and the overall scores for workload were significantly impacted by the type of motion control: when HG was used, the task completion time increased. Particularly, using HG had the potential to increase the overall workload score, while physical laboriousness was also potentially increased by HG. Conversely, unloading accuracy, heart rate, and mental demand were not affected by motion control approaches. Generally, the expert group spent more time completing the tasks, but they performed better unloading accuracy than the novices in all methods. Ninety-one percent of the experts gave positive feedback on the reproducibility of the prototype system.

Simulation study on power system short circuit fault based on EMTP

Electromagnetic transient simulation program EMTP is a common simulation commercial software in power system. It can effectively analyze and study power system. In this paper, EMTP is used to build the power system simulation model, and a variety of short-circuit faults in the power system are simulated and analyzed. The results show that the results accord with the actual theory, and the waveform can accurately and intuitively investigate the dynamic characteristics of power system faults. In addition, through the simulation comparison and analysis between different faults, it can be seen that the three-phase short-circuit fault is the most serious fault in the power system, which should be avoided in the actual production and life. This shows that EMTP is a powerful tool for power system simulation research, and provides a reference for the actual equipment selection requirements of the project.

Phasing out the blast furnace to meet global climate targets

Phasing out the blast furnace to meet global climate targets

Interactive Water Level Control System Simulator Based on OMRON CX-Programmer and CX-Designer

Abstract— Programmable Logic Controller (PLC) is an essential component in industrial automation where it acts as the backbone of the system. In line with Industrial Revolution (IR) 4.0, most industrial and manufacturing sectors move towards automation systems. Preparing university students about automation and PLC fundamental knowledge and skill is crucial before graduation, where the preoccupied knowledge will enhance graduate employability. Fulfilling this task, universities have to prepare the necessary equipment in the laboratory for teaching and learning purposes. The problem arises when certain universities with budget constraints cannot purchase the equipment for the PLC embedded system as huge costs have to be borne by universities. Thus, an alternative approach has to be taken where the main objective of this paper is to develop an interactive water level control system simulator as a substitution of the expensive automation PLC embedded system for teaching and learning purposes. OMRON software, namely CX-Programmer and CX-Designer used to design and develop an interactive water level control system simulator. In addition, the interactive water level control will be embedded with a PLC component that replicates the actual automation system laboratory equipment. Moreover, universities with a limited budget can utilize the tool for teaching and learning purposes of the PLC and automation system, which is the main contribution of this paper. Keywords—Water Level Control System, Programmable Logic Controller, Simulator, CX-Programmer, CX-Designer.

Development of simulation platform for Automatic Storage production line

This paper develops a simulation platform of automatic storage production line based on 89C51 single chip microcomputer, which provides students with an interactive classroom learning and laboratory practical activities to assist the practical learning of industrial robot and programmable controller. The test shows that the transformation of the simulation code into the corresponding actual equipment is real, feasible, safe and reliable.

The Influence of Weather in Determining the Probability of Detecting an Object in Distress during SAR Operations

Purpose: Planning an effective rescue operation is a subject of many factors. The success of SAR operation depends primarily on the accuracy of the information received and the conditions on the scene. Due to the impossibility of eliminating the danger and risk of accidents at sea, it becomes necessary to prevent and minimize their possible consequences to the greatest extent possible. The basic idea of the study is to develop a research scheme to estimate both the most likely position of an object in distress and to determine the possibility of a successful SAR operation. Design/Methodology/Approach: The research was carried out using the SAR Navi-Harbour. TRANSAS 5000 module to plan and monitor rescue actions in a selected area. Simulations of conducting SAR operations were designed in the Baltic Sea area using the actual available SAR equipment. Findings: This paper presents the influence of various factors on the effectiveness of SAR operations. It determines the probability of object detection (POD) and the likelihood of success (POS) for different weather condition scenarios that allow an analysis of the effectiveness of used SAR equipment and chosen searching patterns, which directly impact the success of the SAR operation. Practical Implications: The results obtained in the simulations support the decision-maker at all stages of SAR rescue planning. The use of the simulation method becomes an alternative to the traditional way of planning. Originality/Value: The article shows the need to use available market simulators to support the whole SAR operation at each stage.

A Study on the Response of the Rehabilitation Lower Device using Sliding Mode Controller

This paper presents the application of the sliding mode controller to simulate the control of a 3 Degree of Freedom (DoF) robot model that supports lower extremity rehabilitation exercises for stroke patients. The 3 DoF robot model has an established dynamic differential equation for each joint. This paper studied the response of links of the research model with a sliding mode controller proposed as the control solution. Matlab software was used in simulations of ankle, knee, and hip joints' drive for 2 cases, without and with load. Compared with other studies, the research results show that the sliding controller results in slight angular errors when applied to the research model, while the torque of the joints remains low. This result is the basis for calculating and selecting parameters for the actuator when manufacturing the actual equipment.

Surface Defect Detection on Nuclear Power Plant Components Based on Photometric Stereo under Near-Field LED Light

To improve the visual inspection of nuclear power plant components, this study introduces the technology of three-dimensional reconstruction framework based on photo metric stereo under near-field LED lighting. An iterative algorithm is proposed to estimate the K value of different light sources and the light6 intensities for various image pixels. Combined with the calculation method of the spatial position of the light source and the detected surface points, the light intensity and light direction of different points on the detected surface are estimated under the illumination of near-field LED point light source. A surface defect detection system is designed based on this technology, and it is verified by experiments on surface damage samples and actual nuclear power equipment. The results show that this system can obtain three-dimensional surface data, and for scratch-type defects, it can further achieve accurate depth measurement. Therefore, it can effectively improve the detection ability of surface defects.

Improved internal model control method for carbon content of argon–oxygen refining ferrochromium alloys

We propose an improved internal model control method for the carbon content in the production process of argon–oxygen refining ferrochromium alloys. In the actual process, the control output is restricted and cannot fully demonstrate the control effect. Therefore, by decomposing the traditional internal model controller, we achieved saturation compensation, overcoming this limitation. In addition, by referring to the current production process, the smelting stages with different carbon-content ranges were determined. Combined with the actual equipment conditions, an anti-saturation internal model controller structure and a controller saturation numerical expert system were constructed, forming a fully improved internal model control system. The proposed method fully utilizes the steady-state error-free characteristic of the internal model control, achieving the preset control goal and significantly shortening the smelting time and improving the smelting efficiency.

Ergonomic Hazards in the Workplace: Assessment, Evaluation and Prevention in the Educational Environment of Holy Cross College

This research was conducted to assess, evaluate and prevent the ergonomics hazards in the educational environment of Holy Cross College. College instructors at various workstations across the college facilities are among those that participate. The data was gathered through the use of an online survey form. It consists of 45 questions designed to have insight on the actual equipment setup, work posture, and work design, and environment utilized by the college faculty. The majority of the detected risks are at a critical level and may cause severe loss to the organization's scope, quality, schedule, and cost. The findings provided the necessary safety norms and resources to prevent ergonomic hazards that result in ergonomic health problems. All hazards designated as critical can be kept to minimum if actions and reactions are appropriately implemented by the relevant parties. As a result, the likelihood and magnitude of its occurrence and effects are reduced.

Digital Twin and Manufacturing Simulation Integrated Platform embedded in cyber-physical system

Simulation on manufacturing process of production line is essential to reduce the cost and time of production line layout design. Traditional simulation methods either have low fidelity or depend on actual equipment and external tools. Digital Twin is a core element in Industry 4.0 and is viewed as the next generation of simulation. However, applying Digital Twin to simulate manufacturing process is inadequately researched. To simulate and assess the manufacturing process of production lines in advance, this paper proposes Digital Twin and Manufacturing Simulation Integrated Platform (DTMSIP) embedded in Cyber-Physical System (CPS). Powered by the Plug-and-Play CPS, DTMSIP can serve the function of both monitoring and simulation, where fidelity is ensured by precise mapping of Digital Twin. After DTMSIP is established for a reconfigurable production line, DTMSIP as a simulation method is validated on a reconfiguration evaluation problem in this paper.

A Classifier of Railway Power Supply Equipment Concern Importance Based on Ensemble Learning

It is of great significance to evaluate the condition of equipment and identify the degree of important concern of equipment for formulating reasonable condition maintenance strategy and ensuring the safe and stable operation of railway power grid. In view of the characteristics that the overload operation state and maintenance interval of equipment are closely related to the equipment state level, the evaluation feature vector composed of five indexes, including overload time of heavy overload equipment, whether the central power supply equipment is in the city center, unrepaired time of equipment, whether it is the power supply equipment and the voltage level of equipment is maintained, is constructed in this subject. In addition, based on the Stacking ensemble learning framework, a hybrid ensemble learning framework algorithm is proposed, which combines the single Bagging and Boosting framework algorithms, and realizes the mapping between feature vectors and importance levels. The data of actual railway power grid equipment are substituted into the model for analysis, and the model is compared with the random forest model based on single ensemble learning algorithm. The simulation results show that compared with other ensemble learning algorithms, the accuracy of equipment state evaluation is significantly improved by using the combination model of stacking ensemble learning method.

Development of a university-industry collaboration model towards work-ready engineering graduates

ABSTRACT Background One of the many challenges faced by universities in developing countries is to equip graduates with practical skills and knowledge for the demanding workforce. The traditional textbook-oriented lecture lacks up-to-date industrial practices. Background Purpose: This study highlights the development of a university-industry collaboration model for producing work-ready engineering graduates. An experienced practising engineer from Universiti Tunku Abdul Rahman’s Industry Advisory Panel representing Techkem Group was invited as a guest lecturer for two undergraduate engineering elective courses. Besides conventional lectures and tutorial sessions, the invited guest lecturer with vast industrial exposure also demonstrated actual engineering equipment working principles to the undergraduate students. Sample A total of 80 final year students and 10 lecturers took part to provide the feedback. Design and methods Feedback from students and lecturers was analyzed to determine the acceptance level towards incorporating industrial practice knowledge in these elective courses. Results The integration of current industrial practices into these courses has shown encouraging response from both students and lecturers with scoring between 80.8 and 93.3 points out of the maximum 100 points. Conclusions Positive results from the respondents have paved the path for the future development of such collaboration. Corporate social responsibility engagement by the industry as well as initiative to improve the teaching and learning process for elective courses by the university are essential aspects for a mutually beneficial collaboration in this model.

Design of optical sighting telescope training system based on simulated target

In order to solve the practical operation training problem of an optical sighting telescope in certain weapon system, the application research of simulated target technology is carried out. According to the tactical and technical characteristics of sight and battlefield target, based on the embedded simulation framework, a series of simulation target technologies, such as constructing the optical characteristic model of target, fitting the target trajectory, encapsulating the characteristic information of target in the typical scene, are used to explore the technical route of actual combat training relying on actual equipment and simulation target, and realize the training scene and its model. The application results show that the method is feasible.

A non-intrusive approach for fault detection and diagnosis of water distribution systems based on image sensors, audio sensors and an inspection robot

Fault diagnosis is important to maintain the normal operation of air-conditioning systems, reduce the energy consumption in buildings, and increase the service life of air-conditioning system equipment. We present a novel approach for fault detection and diagnosis system that relies on image and audio sensors and relevant algorithms.This paper proposes a fault diagnosis algorithm based on a robot that can automatically capture audio and image signals from microphone arrays and cameras during inspection in a chiller room. It includes audio- and image-based fault diagnosis algorithms. The validity of the algorithm combined with sensors is verified using data from actual equipment in a chiller room.The audio-based algorithm, which can monitor the abnormal sound of pumps to detect faults, utilizes Fourier transform, a finite impulse response digital filter, and an autoregressive integrated moving average model. We analyze the frequency domain of the pump signal and set the appropriate threshold to monitor abnormal signals based on the fitted model. Meanwhile, the image-based algorithms are divided into three sections to achieve three functions: 1) an AlexNet convolutional neural network is modified to classify the images of the chiller room equipment obtained by the visible light camera; 2) image morphology methods and trigonometric functions are used to read the dials’ indicators acquired by the visible light camera; and 3) optical character recognition is used to obtain the highest temperature value in the infrared image of the pump captured by the infrared camera, which helps maintenance staff verify the operation of the pump and detect faults as soon as possible.These diagnostic algorithms are non-intrusive, low cost, and easy to deploy. Combined with real-time data collection from the sensors on the robot, the algorithms can effectively improve the intelligence of the equipment room and allocate human resources more reasonably.

Upstream Critical Heat Flux and Its Design Implications

While most critical heat flux (CHF) studies focus on relatively straightforward geometries, actual equipment applications are complex. This paper summarizes literature which provides insights into the effects of selected inlet conditions on CHF and the occurrence of upstream CHF. Vertical smooth bore tube CHF tests found that the concept of “local conditions hypothesis”, though not universally defensible, provides an adequate basis for applying CHF data to design. Upstream CHF indications have been found to be associated with a minimum in the CHF versus quality curve which has been attributed to the transition from intermediate flow regimes to annular flow regimes. Design implications are discussed including: 1) for vertical smooth bore tubes, upstream CHF is generally not observed except at very high masses where specific data are required - at lower mass fluxes, special design procedures are needed where nonuiform circumferential heating is present, 2) for inclined smooth bore tubes, design specific data are needed as upstream CHF observations are more prevalent, 3) for vertical and inclined multi-lead ribbed bore tubes (common in the power industry), minimum mass fluxes are specified to avoid upstream CHF, and 4) coiled and serpentine tubes are discussed.

EBSD Evaluation of Creep Damage Process for Fine Grained Heat Affected Zone of Serviced Mod.9Cr-1Mo Steel

Type IV creep damage in fine grained heat affected zone of Mod.9Cr-1Mo steel has been concerned and extensively studied for steam piping of thermal power plants. However, the evaluation of Type IV damage by EBSD measurement is not enough. Serviced materials that have been used for a long time in an actual equipment are considered to effective materials for investigating microstructural changes in a long-term region. In this study, SEM observation and EBSD measurement were performed on the material of the Mod. 9Cr-1Mo steel FGHAZ used on the actual equipment and interrupted test specimen. As a result, as the creep progressed, strain concentration due to dislocation accumulation was observed in the portion near the voids, and recovery due to dislocation reduction was confirmed in the non-void portion, and the mechanism of Type IV damage caused by local strain concentration was confirmed. ΔKAM, which is obtained by subtracting KAMlocal, which is the KAM value near the void portion, and KAM0, which is the KAM value of the nonvoid portion, showed a monotonic increase with respect to the creep damage rate t/tr. The possibility that creep damage can be evaluated by this index was shown. In addition to examining the estimation formula expressing the change of the KAM value, it was found that the macroscopic and local void numbers could be evaluated from the KAM value.

Alignment of linear polymeric grains for highly stable N-type thin-film transistors

Summary Temperature-insensitive properties are attractive for most electronics, including polymeric semiconducting devices. Especially, polymeric field-effect transistors (FETs) with high mobility have been important research targets due to their broad applications. However, polymeric FETs with stable charge transport operating at extremely cold or hot zones are faced with enormous challenges. In this study, the polyacrylonitrile was found to significantly tune the sizes of pre-aggregates of polymers in solutions and the crystallinity of the polymeric films. The orientation of 5–25 μm linear grains in the films were prepared through the bar-coating process with polyacrylonitrile as an additive, which stabilized the electron mobility over a wide range of temperatures. The linear-grain morphology of the film contributed to reducing the holes and grain boundaries in the transport paths of carriers. Typically, the top-gate FETs based on P(NDI2OD-T2) displayed a stable electron transporting behavior from 200 to 460 K, with mobility greater than 3.5 cm2V−1s−1.