25 research outputs found

    Back calculation Anti Windup PID controller on Several Well-Known Tuning Method for Glycerin Bleaching Process Temperature Regulation

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    The aim of this paper is to comprehend the performance of back calculation anti windup scheme with difference tracking time constant, Ta on Proportional – Integral - Derivative (PID) controller for improving temperature regulation of glycerin bleaching process.  Several available well tuning methods including Ziegler Nichols (ZN), Internal Model Control (IMC) and Integral Square Error (ISE)-Load are used and analyzed. The performance of the controller tuning methods are  compared based on percentage of overshoot, settling time, rise time and time to recovery on the presence of disturbance. From the results, the best performance of temperature regulation for glycerin bleaching process can be reached by using ISE-Load tuning with tracking time constant, Ta equal to derivative time constant, Td.&nbsp

    FPGA technology in process tomography

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    The aims of this paper are to provide a review of the process tomography applications employing field programmable gate arrays (FPGA) and to understand current FPGA related researches, in order to seek for the possibility to applied FPGA technology in an ultrasonic process tomography system. FPGA allows users to implement complete systems on a programmable chip, meanwhile, five main benefits of applying the FPGA technology are performance, time to market, cost, reliability, and long-term maintenance. These advantages definitely could help in the revolution of process tomography, especially for ultrasonic process tomography and electrical process tomography. Future work is focused on the ultrasonic process tomography for chemical process column investigation using FPGA for the aspects of low cost, high speed and reconstructed image quality

    Non-invasive ultrasonic tomography: liquid/gas flow visualization

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    This paper presents the non-invasive ultrasonic tomography system for imaging liquid and gas flow. Transmission-mode approach has been used for sensing the liquid/gas two-phase flow, which is a kind of strongly inhomogeneous medium. The algorithms used to reconstruct the concentration profile for two-phase flow using fan-shaped beam scanning geometry were presented. Experiments showed that the performance of the system is acceptable. Results of the experiments using LBPA, HRA and HBRA were discussed

    Solid/gas concentration measurements using multiple fan beam optical tomography

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    The application of optical sensors in process tomography involves using non-intrusive sensors to obtain vital information in order to produce images from the dynamic characteristics of a process system. Multiple fan beam projection technique here is defined as allowing more than one emitter to transmit light at the same time using the switch-mode fan beam method. For the thirty-two pairs of sensors used, the 2-projection technique and 4-projection technique are being investigated. Sixteen sets of projections will complete one frame of light emission for the 2-projection technique while eight sets of projection will complete one frame of light emission for the 4-projection technique. The data obtained from optical fibre sensors will then be reconstructed into image using the Linear Back Projection and Iterative Reconstruction algorithms through Visual C++ programming. Concentration measurements and series of error analyses will determine the feasibility of the optical fibre sensors to perform as an instrument in solid flow visualization

    A novel hybrid binary reconstruction algorithm for ultrasonic tomography

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    This paper presents a novel image reconstruction algorithm namely the Hybrid Binary Reconstruction Algorithm (HBRA). The algorithm is capable to improve the noise in the conventional back-projection based algorithm. The comparison between the Linear Back Projection Algorithm (LBPA) and the Hybrid Binary Reconstruction Algorithm have been made. The results are positive and are presented at the end of the paper

    Application of transmission-mode ultrasonic tomography to identify multiphase flow regime

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    This paper presents an application of ultrasonic tomography where the main objective is to identify the multiphase flow regime which is liquid, gas and solid at once. The system was designing non-invasively by using offline method. The transmission mode with fan shaped beam back projection had been implemented for sensing purposes where 8x8 projections were produced. Beside, the linear back projection (LBP) algorithm was implemented in the software system for the image reconstruction part. Experiments show that the multiphase flow regime for liquid, gas and solid at once can be identifying by using ultrasonic tomography. The results of experiments and possible future improvement were also discussed

    Non-invasive imaging of liquid/gas flow using ultrasonic transmission-mode tomography

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    This paper details the development of non-invasive ultrasonic tomography for imaging liquid and gas flow. Transmission-mode approach has been used for sensing the liquid/gas two-phase flow, which is a kind of strongly inhomogeneous medium. A 16-pair of ultrasonic sensors have been used. By using low excitation voltage of 20 V, fan-shape beam ultrasonic transmitters will emit ultrasonic pulses to the receivers. The investigations were based on the transmission and the reception of ultrasonic sensors that were mounted circularly on the surface of experimental vessel. The algorithms used to reconstruct the concentration profile for two-phase flow using fan-shape beam scanning geometry were presented. By using Hybrid-Binary Reconstruction algorithm (HBR), a real-time of ultrasonic transmission-mode tomography had been developed. Experiments showed that the performance is acceptable with the image reconstruction speed of ten frames per second. The results of the experiments and possible future improvements were also discussed

    Optical tomography system: charge-coupled device linear image sensors

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    This paper discussed an optical tomography system based on charge-coupled device (CCD) linear image sensors. The developed system consists of a lighting system, a measurement section and a data acquisition system. Four CCD linear image sensors are configured around a flow pipe with an octagonal-shaped measurement section, for a four projections system. The four CCD linear image sensors consisting of 2048 pixels with a pixel size of 14 micron by 14 micron are used to produce a high-resolution system. A simple optical model is mapped into the system's sensitivity matrix to relate the optical attenuation due to variations of optical density within the measurement section. A reconstructed tomographic image is produced based on the model using MATLAB software. The designed instrumentation system is calibrated and tested through different particle size measurements from different projections

    Design and modelling of ultrasonic tomography for two-component high-acoustic impedance mixture

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    This paper describes the design and modelling of ultrasonic tomography for two-component high-acoustic impedance mixture such as liquid/gas and oil/gas flow which commonly found in chemical columns and industrial pipelines. The information obtained through this research has proven to be useful for further development of ultrasonic tomography. This includes acquiring and processing ultrasonic signals from the transducers to obtain the information of the spatial distributions of liquid and gas in an experimental column. Analysis on the transducers' signals has been carried out to distinguish between the observation time and the Lamb waves. The information obtained from the observation time is useful for further development of the image reconstruction

    Modeling of a charge coupled device based optical tomographic instrumentation system for particle sizing

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    This research investigates the use of charge coupled device (CCD) linear image sensors in an optical tomographic instrumentation system used for sizing particles. Four CCD linear image sensors are configured around an octagonal shaped flow pipe for a four projections system. The measurement system used four CCD linear image sensors consisting of 2048. pixels with a pixel size of 14 by 14 µm. Hence, a high-resolution system is produced. Three mathematical models based on the effects due to particles, light sources and diffraction are discussed. The models are used to simulate the actual process in order to understand the limitations of the designed system
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