110 research outputs found

    Control of Plant Wide Processes Using Fractional Order Controller

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    Fractional order PID controller is gaining popularity because the presence of two extra degrees of freedom, which have the potential to meet up the extra degrees in terms of uncertainty, robustness, output controllability .In other words, the fractional order PID controller is the generalization of the conventional PID controller. In the current study, the fractional order PID controller is designed and implemented for the complex and plant-wide processes. Distillation is the most effective separation process in the chemical and petroleum industries but with a drawback of energy intensivity To reduce the energy consumption two distillation columns can be combined into one column, which is known as dividing wall distillation column (DWC).Though the control of DWC has been addressed but it requires further R&D efforts considering the complexity in control of this process In this work the DWC is controlled by the advanced control strategy like fractional order PID controller. One of the challenging field in the process control is to design control system for the entire chemical plant. We have presented the control system for the HDA plant by implementing the fractional order PID controller. Both the discussed processes are multi-input-multi-output (MIMO) system and these processes are difficult to tune because of the presence of the interaction between the control loops. For the DWC process, the traditional simplified decoupler is used, while for the HDA plant process the equivalent transfer function model is used to handle the MIMO system. For tuning of the fractional-order PID controllers the optimization techniques have been used. The DWC controllers have been tuned by the ev-MOGA multi objective algorithm and the HDA plant controllers are tuned by the cuckoo search method

    Path Planning of Mobile Agents using AI Technique

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    In this paper, we study coordinated motion in a swarm robotic system, called a swarm-bot. A swarm-bot is a self-assembling and self-organizing. Artifact composed of a swarm of s-bots, mobile robots with the ability to connect to and is connect from each other. The swarm-bot concept is particularly suited for tasks that require all-terrain navigation abilities, such as space exploration or rescue in collapsed buildings. As a first step toward the development of more complex control strategies, we investigate the case in which a swarm-bot has to explore an arena while avoiding falling into holes. In such a scenario, individual s-bots have sensory–motor limitations that prevent them navigating efficiently. These limitations can be overcome if the s-bots are made to cooperate. In particular, we exploit the s-bots’ ability to physically connect to each other. In order to synthesize the s-bots’ controller, we rely on artificial evolution, which we show to be a powerful tool for the production of simple and effective solutions to the hole avoidance task

    Video Object Tracking Using Motion Estimation

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    Real time object tracking is considered as a critical application. Object tracking is one of the most necessary steps for surveillance, augmented reality, smart rooms and perceptual user interfaces, video compression based on object and driver assistance. While traditional methods of Segmentation using Thresholding, Background subtraction and Background estimation provide satisfactory results to detect single objects, noise is produced in case of multiple objects and in poor lighting conditions. Using the segmentation technique we can locate a target in the current frame. By minimizing the distance or maximizing the similarity coefficient we can find out the exact location of the target in the current frame. Target localization in current frame was computationally much complex in the conventional algorithms. Searching an object in the current frame using these algorithms starts from its location of the previous frame in the basis of attraction probably the square of the target area, calculating weighted average for all iteration then comparing similarity coefficients for each new location. To overcome these difficulties, a new method is proposed for detecting and tracking multiple moving objects on night-time lighting conditions. The method is performed by integrating both the wavelet-based contrast change detector and locally adaptive thresholding scheme. In the initial stage, to detect the potential moving objects contrast in local change over time is used. To suppress false alarms motion prediction and spatial nearest neighbour data association are used. A latest change detector mechanism is implemented to detect the changes in a video sequence and divide the sequence into scenes to be encoded independently. Using the change detector algorithm (CD), it was efficient enough to detect abrupt cuts and help divide the video file into sequences. With this we get a sufficiently good output with less noise. But in some cases noise becomes prominent. Hence, a method called correlation is used which gives the relation between two consecutive frames which have sufficient difference to be used as current and previous frame. This gives a way better result in poor light condition and multiple moving objects

    Robust Short-term Operation of AC Power Network with Injection Uncertainties

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    With uncertain injections from Renewable Energy Sources (RESs) and loads, deterministic AC Optimal Power Flow (OPF) often fails to provide optimal setpoints of conventional generators. A computationally time-efficient, economical, and robust solution is essential for ACOPF with short-term injection uncertainties. Usually, applying Robust Optimization (RO) for conventional non-linear ACOPF results in computationally intractable Robust Counterpart (RC), which is undesirable as ACOPF is an operational problem. Hence, this paper proposes a single-stage non-integer non-recursive RC of ACOPF, using a dual transformation, for short-term injection uncertainties. The proposed RC is convex, tractable, and provides base-point active power generations and terminal voltage magnitudes (setpoints) of conventional generators that satisfy all constraints for all realizations of defined injection uncertainties. The non-linear impact of uncertainties on other variables is inherently modeled without using any affine policy. The proposed approach also includes the budget of uncertainty constraints for low conservatism of the obtained setpoints. Monte-Carlo Simulation (MCS) based participation factored AC power flows validate the robustness of the obtained setpoints on NESTA and case9241pegase systems for different injection uncertainties. Comparison with previous approaches indicates the efficacy of the proposed approach in terms of low operational cost and computation time.Comment: 16 pages, 5 figures, 5 table

    ANATOMICAL AND BIOCHEMICAL ASPECTS OF THEVETIA PERUVIANA L. A COMMONLY PLANTED ROADSIDE TROPICAL SHRUB OF BHUBANESWAR, ODISHA

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    Objective: Air pollution is one of the most severe environmental problems of developing cities which adversely affects both plant and human life. However, roadside plants in the urban locations help in reducing the pollution level from the air through foliar surface and act as pollution sink. In this work, an attempt was made to understand the impact of air pollution on urban roadside plants which act as bio indicator.Methods: A study was conducted to check the impact of urbanization on air pollution by analyzing anatomical and biochemical aspects of Thevetia peruviana L. For anatomical analysis, the transverse sections of leaves were observed under a microscope; whereas for biochemical analysis, the estimation of chlorophyll, carotenoid and protein were determined by spectrophotometric methods. On the other hand, antioxidant enzyme assays, as well as specific activity staining, were performed to study the antioxidant potential. To investigate the antioxidant activity of the leaf extracts, an assay for catalase (CAT), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) were performed. Isoforms of CAT, GPX and SOD were separated using native polyacrylamide gel electrophoresis (PAGE) and their activities were analyzed.Results: Analysis of data revealed that the anatomical disturbances significantly occurred in exposed plants of various sites. Among biochemical parameters, photosynthetic pigments such as chlorophyll a, chlorophyll b, total chlorophyll and carotenoid content were found to be decreased. A maximum (7.65±0.51, 3.78±0.56,11.43±0.91, 5.63±0.55 mg/g, respectively) decrement was noticed in leaves of the Pokhariput plant in comparison to Khorda NH5 (19.44±1.08, 10.12±1.03, 29.56±2.32, 10.22±1.21 mg/g, respectively) which is taken as control one. To determine the effect of air pollution on proteins, leaf extracts were analyzed by the Lowry method and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The substantial decrement of total protein and alteration in polypeptides were noticed in polluted sites. Meanwhile, the enhancement of antioxidant enzyme activities such as CAT, GPX and SOD were also detected.Conclusion: The increment of antioxidant enzymes and alteration of proteins, suggesting the activation of defensive mechanisms in selected plants under air pollution stress and also the plants made physiological and biochemical adjustments to overcome the oxidative damage

    Shock Tube as an Impulsive Application Device

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    Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed

    A Distributed-Controlled Harmonic Virtual Impedance Loop for AC Microgrids

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    A Comprehensive Survey on Different Control Strategies and Applications of Active Power Filters for Power Quality Improvement

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    This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Power quality (PQ) has become an important topic in today’s power system scenario. PQ issues are raised not only in normal three-phase systems but also with the incorporation of different distributed generations (DGs), including renewable energy sources, storage systems, and other systems like diesel generators, fuel cells, etc. The prevalence of these issues comes from the non-linear features and rapid changing of power electronics devices, such as switch-mode converters for adjustable speed drives and diode or thyristor rectifiers. The wide use of these fast switching devices in the utility system leads to an increase in disturbances associated with harmonics and reactive power. The occurrence of PQ disturbances in turn creates several unwanted effects on the utility system. Therefore, many researchers are working on the enhancement of PQ using different custom power devices (CPDs). In this work, the authors highlight the significance of the PQ in the utility network, its effect, and its solution, using different CPDs, such as passive, active, and hybrid filters. Further, the authors point out several compensation strategies, including reference signal generation and gating signal strategies. In addition, this paper also presents the role of the active power filter (APF) in different DG systems. Some technical and economic considerations and future developments are also discussed in this literature. For easy reference, a volume of journals of more than 140 publications on this particular subject is reported. The effectiveness of this research work will boost researchers’ ability to select proper control methodology and compensation strategy for various applications of APFs for improving PQ.publishedVersio
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