Control Technology Research Articles

Optically controlled variable damping system based on PLZT ceramic/ERF in rectangular microchannel

Variable damping control technology based on intelligent materials of electromagnetic excitation has been widely used in the field of (semi-) active vibration control and fluid control. Unfortunately, a major drawback is the electromagnetic noise interference and low response speed. In this paper, a new optically controlled variable damping system based on PLZT ceramic/electrorheological fluid (ERF) is proposed. The mathematical models of the photovoltage generated by PLZT ceramics and the pressure difference between the two ends of the microchannel are established and verified by numerical simulation in COMSOL Multiphysics. Meanwhile, with the increase of light intensity, liquid flow rate and decrease of microchannel height and width, the pressure difference shows an uptrend. Optically controlled variable damping system based on PLZT ceramic/ERF is a control method with the advantages of a clean excitation source, remote control, no electromagnetic interference, and fast response speed, and has a good application prospect in the field of vibration control and fluid control.

Design of adaptive-PID-Smith control in the two-mixing tank series

ABSTRACT A control strategy must be developed to maintain the product composition of the two- or more-mixed-flow reactor series. In this research, a two-mixing tank series (TMTS) was utilized in the laboratory to approach the two-mixed flow reactors’ problems. Both tanks are designed to overflow so that the volume remains constant. The salt solution was directly fed to Tank 1, while the water was charged to both tanks as the mixing progressed. The output of Tank-1 flowed to Tank-2 through a rather long pipe, resulting in dead time in Tank-2. The Smith predictor was applied to overcome dead time. The PRC (process reaction curve) method was used to tune the PID (proportional-integral-derivative) parameters of Tank-1 and Tank-2. The novel composition controls, adaptive-PID (APID) and modified metaheuristic adaptive-PID (MMAPID), have been proposed and compared with conventional PID. The mathematical models were rigorously examined through XCOS simulations. The processing system is considered sensitive to changes in input disturbances since the process time constants of both tanks were quite low. The dead time of 0.5 minutes was found in Tank 2. The PID parameters produced by PRC experiments resulted in stable responses to changes in the disturbance system. As shown in the dynamic simulation study, both novel APID and MMAPID give almost the same results; their responses are faster than the conventional PID. Based on the integral absolute error (IAE) results, APID with scheduling PID parameters produced the smallest IAE and outperformed the conventional PID. The results of the study highlight APID and MMAPID potential in PID control applications for composition control in a TMTS. The combined APID-Smith and MMAPID-Smith were able to overcome the dead time well. This study creates opportunities for engineers and professionals to use cutting-edge control technologies, improving automation and chemical process industries.

Effect of Polymer and Crosslinker Concentration on Static and Dynamic Gelation Behavior of Phenolic Resin Hydrogel

The application results of profile control and water plugging technology are highly related to the gelation time and strength of phenolic resin hydrogel. In this work, a hydrogel solution was prepared by fully mixing the prepared polymer solution with a crosslinker. The static gelation process of PFR hydrogel in ampoule bottles and porous media was analyzed by changes in the viscosity and residual resistance coefficient. Then, the dynamic gelation of the PFR hydrogel in porous media was tested using a circulating flow device, and the changes in viscosity and injection pressure were analyzed during the dynamic gelation process. Finally, the effects of the polymer concentration and crosslinker concentration on dynamic gelation were analyzed. The initial gelation time and final gelation time in porous media were 1–1.5 times and 1.5–2 times those in ampoule bottles under static conditions, respectively. The initial dynamic gelation time in porous media was 2–2.5 times and 1.5–2 times the initial static gelation times in ampoule bottles and porous media, respectively. The final dynamic gelation time was four times and two times the initial static gelation times in ampoule bottles and porous media, respectively. The production after dynamic gelation in porous media comprised hydrogel aggregates and water fluid, leading to a high injection pressure and low viscosity of the produced liquid. As the concentration of polymer and crosslinker increased, the dynamic gelation time was shortened and the gel strength was increased. In the dynamic gelation process in porous media, the phenol resin hydrogel could migrate deeply, but it was limited by the concentrations of the polymer and crosslinker. The results of subsequent water flooding showed that the polymer hydrogel had a good plugging ability after dynamic gelation. The deep reservoir could only be blocked off in the subsequent water flooding process when the migration of hydrogel happened in the dynamic gelation process.

Highly stable Brillouin laser with controllable tuning based on fiber ring resonator

Abstract The design and fabrication processes of stimulated Brillouin laser (SBL) is complex, and it is affected by many factors such as temperature and resonance shift. In this study, we have fabricated a Brillouin laser using fiber ring resonator (FRR), with Q factor=7.1×10^8, resonance depth (h)=96%, and the free spectral range (FSR) automatic feedback control technology is proposed to realize the accurate matching of the resonant mode and the Stokes mode. The influence of temperature on the SBL frequency shift is suppressed. The fluctuation range of SBL’s frequency decreases by 5 times. The maximum steady state output of SBL at the best matching position is realized, and output power fluctuation range decreases by 15 times. The power stability of SBL reaches 4.85×10^(-6), which is improved by two orders of magnitude. This simple scheme provides convenience for the application of SBL, such as sensing and other applications.

A STUDY ON MANAGING MATERIAL HANDLING, STORAGE AND PACKAGING IN FREIGHT FORWARDING AT FLYJAC LOGISTICS PVT LT

This study looks into the difficulties and practices that the freight forwarding industry is currently facing in these areas. A combination of quantitative data collection through surveys and qualitative insights gained from interviews with industry experts were combined in a mixed-method research approach. Thematic analysis and statistical methods were used for data interpretation and analysis. The results indicate that there exist noteworthy prospects for enhancing material handling procedures, optimizing storage, and refining packaging tactics. Among the recommendations are the use of cutting-edge technologies for inventory control, the application of lean concepts to optimize processes, and the creation of environmentally friendly packaging options. Freight forwarding businesses can increase customer satisfaction, cut expenses, and increase efficiency by putting these recommendations into practice. KEY WORDS: Inventory management software, Conveyor systems, Inventory control, Space utilization and Packaging materials.

Vibration control by using active electromagnetic shunt damper

It is well-known that the traditional electromagnetic shunt damping (EMSD) techniques are limited by the damping force of electronic components and require a negative resistance (NR) shunt circuit to enhance performance. However, the NR shunt circuit could lead to the EMSD system being unstable. Addressing this, this study proposes an advanced control system that employs active control technology combined with EMSD for vibration control. We first developed a dimensionless mathematical model of the control system, which was then finely tuned using an adaptive simulated annealing particle swarm optimization algorithm. Subsequently, the relationship between control gain and optimal shunt circuit parameters was predicted using a BP neural network. Finally, the proposed Active-EMSD (AEMSD) was experimentally verified. The experimental results demonstrate that the proposed AEMSD not only surpasses traditional thresholds but also excels in isolating low-frequency vibrations. Compared to traditional EMSD, the proposed AEMSD showed improved effectiveness.

Sand screen selection by sand retention test: a review of factors affecting sand control design

AbstractThe installation of sand screens in open-hole completions in the wellbore is crucial for managing sand production. The main reason for using standalone screens in open-hole completions is their relatively reduced operational complexity compared to other sand control technologies. However, directly applying the screen to the bottom of the hole can lead to an incorrect screen type selection, resulting in an unreliable sand control method. To address this issue, a sand retention test is conducted to evaluate the performance of a standalone screen before field installation. Nevertheless, current sand retention test setups encounter several challenges. These include difficulties in identifying minimum retention requirements, interpreting results in the context of field conditions, and replicating field-specific parameters. The existing sand retention test introduces uncertainties, such as inaccurately replicating field requirements, inconsistent selection of wetting fluids, flow rates, and channel formation, leading to variations in the choice of the optimal screen using this test. In response to these challenges, this study aims to review the sand retention test and propose an improved sand retention method to overcome these problems. The focus of this article is to provide an in-depth analysis of previous sand retention test setups, their contributions to characterizing sand screens, and the parameters utilized in determining test outcomes. Additionally, this review outlines a procedure to investigate the impact of different particle sizes on screen erosion. Key findings emphasize the importance of using high-quality materials, proper screen design to resist damage and erosion, achieving acceptable natural packing behind the screen, and considering factors such as geology, wellbore conditions, and installation techniques. The analysis reveals that a high quantity of finer and poorly sorted sand increases sand production. The study recommends performing a sand pack test closer to reservoir conditions for better evaluation. Premium sand screens demonstrate the highest retention capacity, followed by metal mesh and wire-wrapped screens. Additionally, geotextiles show potential for enhancing sand retention, and screen design affects erosion resistance and service life.

Enhancing energy recovery in automotive suspension systems by utilizing time-delay

This study introduces time-delay active control technology to with the aim of enhancing the system's energy harvesting potential and ride smoothness. The time-delay active suspension represents a nonlinear, multivariable system, and stability analysis in this context is intricate. The mainly challenge lies in effectively leveraging time delay to augment the system's energy collection potential while harmonizing the vehicle's ride comfort and energy efficiency. Addressing this issue, our study proposes enhancing the suspension's energy recovery capability through time-delay control. Initially, the impact of time-delay control parameters on energy collection ability under various operational conditions was analyzed, establishing that appropriate time-delay parameters can enhance energy harvesting capacity. Subsequently, to balance the relationship between vehicle comfort and energy efficiency, the research introduces a method for constructing an optimized objective function based on linear equivalent excitation, thereby quantifying the relationship between system time-domain vibrational response, time-delay control parameters, and external excitations. This approach enables the comprehensive optimization of the suspension system's comfort, safety, and energy efficiency. The control system's stability was analyzed using cluster treatment of characteristic roots method. Finally, simulations and experiments were conducted to evaluate the effectiveness of time-delay active across different scenarios, confirming the efficacy of the proposed control methodology.

Fuzzy finite‐time adaptive control of switched nonlinear systems with input nonlinearities

SummaryThis article addresses the fuzzy finite‐time command filtering tracking control problem for switched nonlinear systems with input nonlinearities via using backstepping technique. An equivalent transformation method is proposed for the purpose of handling the impediment problem caused by the nonlinearity of control input. Finite‐time command filtering control technology can solve the “explosion of complexity” issue, which is caused by the multiple derivation of virtual controllers appeared in the classic backstepping control. A filtering compensation scheme is developed to reduce the filtering error. By combining the fuzzy logic system's approximation ability and the finite‐time theory, a new fast convergence adaptive control scheme is proposed so that the output of the system can converge to a small area near the desired signal and the boundedness of all signals of the controlled system can be assured in finite time. Finally, a simulation example successfully verifies the feasibility of the developed control scheme.

Highly Reactive Peroxide Species Promoted Soot Oxidation over an Ordered Macroporous Ce0.8Zr0.2O2 Integrated Catalyzed Diesel Particulate Filter.

Particulate matter, represented by soot particles, poses a significant global environmental threat, necessitating efficient control technology. Here, we innovatively designed and elaborately fabricated ordered hierarchical macroporous catalysts of Ce0.8Zr0.2O2 (OM CZO) integrated on a catalyzed diesel particulate filter (CDPF) using the self-assembly method. An oxygen-vacancy-enriched ordered macroporous Ce0.8Zr0.2O2 catalyst (VO-OM CZO) integrated CDPF was synthesized by subsequent NaBH4 reduction. The VO-OM CZO integrated CDPF exhibited a markedly enhanced soot oxidation activity compared to OM CZO and powder CZO coated CDPFs (T50: 430 vs 490 and 545 °C, respectively). The well-defined OM structure of the VO-OM CZO catalysts effectively improves the contact efficiency between soot and the catalysts. Meanwhile, oxygen vacancies trigger the formation of a large amount of highly reactive peroxide species (O22-) from molecular oxygen (O2) through electron abstraction from the three adjacent Ce3+ (3Ce3+ + Vö + O2 → 3Ce4+ + O22-), contributing to the efficient soot oxidation. This work demonstrates the fabrication of the ordered macroporous CZO integrated CDPF and reveals the importance of structure and surface engineering in soot oxidation, which sheds light on the design of highly efficient PM capture and removal devices.

Application of histogram of oriented gradient features and support vector machine models in stage lighting control in drama

SummaryThe lighting control of the theatrical stage is directly related to the presentation effect of the program and the audience's experience. With the development of intelligent control technology, the control of lighting effects has been continuously improved. However, the existing stage lighting control lacks intelligence, resulting in poor control effect and weak energy‐saving performance. Based on this, a human contour image classification model using support vector machines (SVM) based on histogram of oriented gradient (HOG) feature extraction method is constructed to achieve stage lighting control. The results show that the revised HOG feature extraction approach achieves recognition performance of 99.6% when the ratio is 0.8. The HOG‐SVM model proposed in the study has the best recognition performance, reaching 99.6%. This indicates that the stage lighting control system based on HOG‐SVM feature extraction constructed in the research can meet the actual needs of stage program performance, which can be applied to stage lighting control to effectively reduce energy consumption.

Construction and reflections on the disease prevention and control system of aquatic organisms based on management perspective

Disease prevention and control are a crucial aspect of fishery management, as they ensure the sustainability of aquacultural systems. With a specific focus on Shandong Province, China, this study outlines the occurrence of diseases in aquatic organisms. It summarizes dynamics that drive disease prevention and control and supports technology, work mode, and emergency prevention and control. In addition, this study also delves into the role of epidemic prevention and control institutions, the upgrading of the social service of disease prevention systems, and insufficient technical support for new species and models. Overall, the findings outlined in this study are intended to achieve the following aims: enhance organizational management of disease prevention and control, standardize the implementation of social services, improve research into prevention and control technologies, and highlight the importance of information technology in disease prevention and control. Based on practical aquaculture production, our aim is to comprehensively analyze the situation of the construction of a disease prevention and control system, strengthen guidance on epidemic prevention technologies, establish a robust animal epidemic prevention system, and propose development strategies, serving as a reference for competent authorities to enhance the disease prevention and control of aquatic organisms.

Optimal declutching control of hinged multiple floating bodies

In deep seas, there is an increasing utilisation of multiple floating structures as devices for harnessing renewable energy, such as hybrid wind-wave energy systems and multi-body wave energy converters. The control strategies have a great influence on the motion characteristics and energy conversion efficiency of these systems. The control technology brings more benefits to the system's performance, yet also introduces more complex challenges. This paper aims to fill the research gap in the control of multiple floating bodies and to propose a novel optimal declutching control method. Declutching control enables discontinuous loading and releasing of the force from power take-off system between bodies. It was found that the feasibility of the proposed method is highly dependent on the choice of objective functions, iteration numbers, and wave frequencies. With appropriate parameters, the declutching control can achieve a variety of objectives for a hinged floating multibody system, such as reducing pitch motion, improving extracted wave power, increasing relative rotational speed, and enhancing power extraction. The control effects on the velocity and the force-velocity phase relationship and how they benefit the objectives are discussed. All objective functions show a better control effect (at least 7.76%) on their respective performance indices than others.

Intelligent Human–Computer Interaction: Combined Wrist and Forearm Myoelectric Signals for Handwriting Recognition

Intelligent Human–Computer Interaction: Combined Wrist and Forearm Myoelectric Signals for Handwriting Recognition

Fruit Sorting by Pizzo-electric Sensor and PLC Controlling

Abstract: The fruit sorting process traditionally relies on visual inspection, primarily considering size as a key quality parameter. However, industries engaged in large-scale fruit trading have turned to image processing technology for sorting, despite its high cost and impracticality for small traders. This paper proposes an alternative sorting system that offers an economical solution suitable for automated fruit sorting at various scales. Aim: The aim of this study is to develop an economical automated fruit sorting system capable of classifying fruits based on their weight, thereby eliminating the need for manual labor and improving sorting accuracy and efficiency. Place and Duration of Study: Department of Electrical Engineering Finolex Academy of Management and Technology, Ratnagiri, Maharashtra, between July 2023 to April 2024. Study Design: This study employs a practical approach to design an automated fruit sorting system that utilizes Programmable Logic Controller (PLC) technology in conjunction with load cells. The system is designed to classify fruits based on their weight as they move along a conveyor belt, thereby automating the sorting process. Methodology: The proposed sorting system integrates PLC technology and load cells to accurately measure and classify fruits based on their weight. By eliminating the need for manual intervention, the system enhances sorting efficiency and accuracy. The system is designed to be cost-effective and suitable for implementation by small traders and farmers. Results: The developed sorting system demonstrates precise, reliable, and consistent sorting outcomes based on fruit weight. By automating the sorting process, the system achieves improved efficiency and productivity compared to traditional manual sorting methods. Moreover, the cost-effectiveness of the system makes it accessible to small traders and farmers seeking to enhance their sorting practices. Conclusion: The proposed sorting system offers an economical and efficient solution for automated fruit sorting, particularly for small traders and farmers. By leveraging PLC technology and load cells, the system provides reliable alternative to costly image processing-based methods. The automation of the sorting process eliminates the risk of errors and inconsistencies associated with manual sorting, while ensuring accurate and quantitative classification based on fruit weight. This sorting system presents a practical approach to improving fruit trading operations, enhancing efficiency, and productivity.

Air pollution mortality from India’s coal power plants: unit-level estimates for targeted policy

Abstract Air pollution from coal-fired electricity generation is an important cause of premature mortality in India. Although pollution-related mortality from the sector has been extensively studied, the relative contribution of individual coal-fired units to the fleet-wide mortality burden remains unclear. Here, we find that emissions from a small number of units drive overall mortality. Units producing just 3.5% of total generation and constituting less than 3% of total capacity result in 25% of annual premature mortality from coal-fired generation. This is a direct consequence of the 200-fold variation that we find in the mortality intensity of electricity generation across units. We use a detailed emissions inventory, a reduced complexity air quality model, and non-linear PM2.5 concentration-response functions to estimate marginal premature mortality for over 500 units operational in 2019. Absolute annual mortality ranges from less than 1 to over 650 deaths/year across units, and the mortality intensity of generation varies from under 0.002 to 0.43 deaths/GWh. Our findings suggest the potential for large social benefits in the form of reduced PM2.5-related premature mortality in India if the highest mortality intensity units are prioritized for the implementation of pollution control technologies or accelerated retirement.

Efficiency of adaptive cruise control in commercial vehicles

AbstractThe evolution of autonomous vehicles hinges significantly upon the advancements in driving assistance systems. Adaptive cruise control, a pivotal component of these systems, warrants continuous real-world examination to assess its operational efficiency. The study investigates these systems integrated into diverse commercial vehicles with a specific focus on the following distances they provide. The findings reveal that camera-based systems offer shorter following distances relative to ISO standards, while radar-based and combined camera and radar-based systems provide larger following distances. The study contributes to understand adaptive cruise control technology and its alignment with safety standards, thereby aiding in the on-going development of self-driving vehicles.

In Situ Bipolar Doping via Mechanically Controlled Dipole Under Water

AbstractPolycrystalline silicon (poly‐Si) is essential in integrated circuits and microelectromechanical systems. In addition, poly‐Si is gaining attention for next‐generation display research with high thermal conductivity, stability, and versatile applications. Conventional fabrication methods for doping patterns involve complex lithography and chemical usage, which have raised environmental concerns. The study of novel methods is necessary for environmental friendliness and a significant simplification of the manufacturing processes. This study introduces a novel bipolar work function control technology utilizing deionized water (DI‐W) and nanonewton‐scale mechanical force using an atomic force microscope. The method is implemented with a mechanically induced SiOx layer on poly‐Si in DI‐W. The induced Si─OH and Si─O bonds decreases the work function, whereas a thicker SiOx layer with a high oxidation state increases the work function. Based on the magnitude of the applied force (26.73–75.24 nN) and additional DI‐W immersion, the induced bond and thickness of the SiOx layer are controlled. Therefore, bipolar work function control is achieved in the range of −0.25–+0.103 eV. In addition, the electrical characteristics of the fabricated p‐ and n‐type poly‐Si diodes are investigated. This method is eco‐friendly and enables bipolar doping patterns in a single process with high efficiency.

Methane Advances: Trends and Summary from Selected Studies

The role of methane (CH4) in the 21st century presents a critical dilemma. Its abundance and clean-burning nature make it a promising energy source, while its potent greenhouse effect threatens climate stability. Despite its potent greenhouse gas (GHG) nature, CH4 remains a crucial energy resource. However, advancements in CH4 capture, utilization, and emissions mitigation are rapidly evolving, necessitating a critical assessment of the advances, their potential, and challenges. This study aims to comprehensively evaluate the current state of the art in these advancements, particularly focusing on the emissions trends, with corresponding global warming potentials of projected CH4 emissions, and a discussion on the advances that have been made towards reducing the impacts of CH4 emissions. The areas of these advances include measurement, computational, numerical modeling, and simulation studies for CH4, emerging technologies for CH4 production, management and control, the nexus of CH4 –X, and case study applications in countries. This study reports on these advances, which involves a technical review of studies, mainly from the last decade, discussing the technical feasibility, economic viability, and environmental impact of these advancements. Our trend analysis reveals that even though the share of CH4 in the GHG mix has been around 19% compared with carbon dioxide (CO2), still, CH4 reduction would need to be highly subsidized because of the high global warming potential it has, compared with CO2. We conclude that while significant progress has been made, further research and development are essential to optimize the performance, scalability, and affordability of these advancements. Additionally, robust policy frameworks and international collaborations are crucial to ensure widespread adoption and maximize the potential that comes with the advancements in the mitigation of the impact of CH4 emission. This study contributes to the ongoing dialogue on balancing the potentials of CH4 with its environmental footprint, paving the way for a future where this versatile resource can be utilized sustainably.

Review of Recent Patents on Smart Bearing

Background: Smart bearing is based on the traditional bearing, which is integrated by sensing devices and control devices, formating a unique bearing structure unit. It uses information processing, automatic control, and other technologies to achieve real-time online monitoring of bearing operating conditions, fault detection, and state control. Compared with ordinary bearings, smart bearings have the characteristics of self-awareness, self-decision, and self-regulation. By analyzing the composition of various types of smart bearings and their working principles, it is beneficial to prospect the future development direction of bearings. Objective: We analyze and organize the patents on smart bearings in recent years, summarize the problems encountered in the development of smart bearings, and propose the development direction of smart bearings in the future to provide a reference for future scientific research. Methods: This paper reviews the patents related to smart bearings and analyzes the composition and structure of smart bearings. The main smart bearings include rolling bearing, sliding bearing, magnetic bearing, and rubber bearing. The principle and structure of these bearings are analyzed. Their advantages and shortcomings are discussed. Results: Through the analysis of relevant patents and papers on smart bearings, the current development status and problems of smart bearings are summarized, the future design of smart bearings is proposed, and the research ideas and directions are proposed. Conclusion: The development of smart bearings is conducive to the timely detection of bearing conditions in the operation process. Except for detection, smart bearings have the functions of judgment, feedback, processing, etc. There are many factors that interfere with the accuracy of the smart bearing judgment and information transfer, so it is necessary to improve the structure and working principle of smart bearings through a variety of measures. In the future, more smart bearings will be invented.