Hugh McCann

Process imaging for automatic control

Contributors Preface THE CHALLENGE D.M. Scott and H. McCann Motivation Roadmap Vista PROCESS MODELING P. Linke, A. Kokossis, J.U. Repke, and G. Wozny Introduction Simulation Versus Optimization Process Models for Imaging and Analysis Process Modeling for Design, Control, and Diagnostics References DIRECT IMAGING TECHNOLOGY S. Someya and M. Takei Introduction Light Sources Sensors Optical Components Applications Machine Vision References PROCESS TOMOGRAPHY B.S. Hoyle, H. McCann, and D.M. Scott Introduction Tomographic Sensor Modalities Image Reconstruction Current Tomography Systems Applications References IMAGE PROCESSING AND FEATURE EXTRACTION D. Zhao Introduction Image Enhancement Image Restoration Segmentation Feature Representation Morphological Image Processing and Analysis References STATE ESTIMATION J. Kaipio, S. Duncan, E. Somersalo, A. Seppanen, and A. Voutilainen Introduction Real-Time Recursive Estimation: Kalman Predictors and Filters On-Line and Transient Estimation: Smoothers Nonlinear and Non-Gaussian State Estimation Partially Unknown Models: Parameter Estimation Further Topics Observation and Evolution Models in Process Industry Example: Convection-Diffusion Models References CONTROL SYSTEMS S. Duncan, J. Kaipio, A. Ruuskanen, M. Malinen, and A. Seppanen Introduction Modeling the Process Feedback Control Control Design Practicalities of Implementing Controllers Conclusion References IMAGING DIAGNOSTICS FOR COMBUSTION CONTROL V. Sick and H. McCann Introduction Combustor Types Imaging in Combustors Results from Combustion Imaging Conclusions References MULTIPHASE FLOW MEASUREMENTS T. Dyakowski and A.J. Jaworski Introduction Flow Pattern Recognition Flow Pattern Imaging Solids Mass Flow Measurements References APPLICATIONS IN THE CHEMICAL PROCESS INDUSTRY D.M. Scott Introduction Applications Related to Process Control Applications Related to Process/Product R&D Conclusion Reference MINERAL AND MATERIAL PROCESSING R.A. Williams Motivation for Development of Image-Based Techniques Design of Comminution Equipment Granular Flow and Bulk Transportation Particle Classification in Cyclones Performance of Flotation Cells and Columns Solids Settling and Water Recovery Microscale Analysis of Granules, Flocs, and Sediments Concluding Remarks References APPLICATIONS IN THE METALS PRODUCTION INDUSTRY J.A. Coveney, N. Gray, and A.K. Kyllo Introduction Detection of Slag Entrainment Measurement of Furnace Refractory Wear Flow Measurement Imaging of Solid State Phase Change Conclusion References INDEX

EXPERIMENTAL-STUDY OF JETS IN ELECTRON-POSITRON ANNIHILATION

Abstract Data on hadron production by e + e − -annihilation at c.m. energies between 30 GeV and 36 GeV are presented and compared with two models both based on first-order QCD but using different schemes for the fragmentation of quarks and gluons into hadrons. In one model the fragmentation proceeds along the parton momenta, in the other along the colour-anticolour axes. The data are reproduced better by fragmentation along the colour axes.

Toward in-cylinder absorption tomography in a production engine

Design requirements for an 8000 frame/s dual-wavelength ratiometric chemical species tomography system, intended for hydrocarbon vapor imaging in one cylinder of a standard automobile engine, are examined. The design process is guided by spectroscopic measurements on iso-octane and by comprehensive results from laboratory phantoms and research engines, including results on temporal resolution performance. Novel image reconstruction techniques, necessary for this application, are presented. Recent progress toward implementation, including details of the optical access arrangement employed and signal-to-noise issues, is described. We present first cross-cylinder IR absorption measurements from a reduced channel-count (nontomographic) system and discuss the prospects for imaging.

Image optimization for chemical species tomography with an irregular and sparse beam array

High-speed tomographic imaging of hostile engineering processes using absorption-based measurements presents a number of difficulties. In some cases, these challenges include severe limitations on the number of available measurement paths through the subject and the process of designing the geometrical arrangement of these paths for best imaging performance. This paper considers the case of a chemical species tomography system based on near-IR spectroscopic absorption measurements, intended for application to one cylinder of a multi-cylinder production engine. Some of the results, however, are also applicable to other hard-field tomographic modalities in applications where similar constraints may be encountered. A hitherto unreported design criterion is presented for optimal beam geometry for imaging performance, resulting in an irregular array with only 27 measurement paths through the subject for the engine application. Image reconstruction for this severely limited geometry is considered at length, using both simulated and experimental phantom data. Novel methods are presented for the practical generation of gaseous phantoms for calibration and testing of the system. The propane absorption coefficient at 1700 nm is measured. Quantitative imaging of propane plumes in air is demonstrated, showing good localization of circular plumes with diameter as small as 1/5 of the subject diameter and excellent imaging of multiple plumes.

Test of Quantum Electrodynamics at {PETRA}

Differential cross sections for the reactions e+e− → e+e− and e+e− → γγ are given for energies between 27.7 and 31.6 GeV. The results agree with the predictions of standard quantum electrodynamics and set lower limits to the usual cut-off parameters of up to 104 GeV. A limit on the Weinberg angle, sin2θW < 0.63, is obtained at unprecedentedly high q2.

A measurement of the electroweak induced charge asymmetry in e+e−→bb̄☆

Abstract The forward-backward charge asymmetry for the process e + e − → b b → μ ± + hadrons has been measured using the JADE detector at PETRA. An asymmetry of (−22.8 ± 6.0 ± 2.5)% was observed at an average center of mass energy of 34.6 GeV. For comparison, an asymmetry of −25.2% is expected on the basis of the standard Glashow-Salam-Weinberg model.

Chemical species tomography by near infra-red absorption

The spatial distribution of chemical species can be a critical determinant of the performance of chemical reactors. One such reactor is the combustion chamber of the Internal Combustion engine. This paper presents a design for the measurement of hydrocarbon concentration distribution within a running engine using near infra-red absorption tomography. The fundamentals of the technique, and design parameters for the equipment are discussed. By utilising micro-optic components, a minimally invasive system is feasible and by utilising advanced laser/photodetector combinations, good temporal performance is anticipated.

Electrode configurations for improved spatial resolution in electrical impedance tomography

This study addresses the numerical treatment applied to the singular values of the sensitivity matrix in the presence of noisy measurements, subsequently suggesting electrode configurations that provide sensitivities with improved characteristics. We begin by examining the impact of the individual singular values on the spatial resolution of the image and then proceed to express the generalized Tikhonov regularization in terms of the generalized singular value decomposition in order to demonstrate how the reconstructed image is synthesized from the individual energy components. The electrode segmentation scheme is then introduced as a feasible configuration offering efficient and improved resolution impedance imaging. Finally, the regularized total least squares algorithm is implemented to provide the linear step solution within Newtons iterative scheme. Images of several reconstructed inhomogeneities are presented, using simulated measurements obtained from the segmented electrodes system.

Experimental evidence for differences in 〈p⊥〉 between quark jets and gluon jets

Abstract We want to dedicate this work to our friend Peter Dittman who contributed so much to the JADE experiment and who died on 31.8.1982.

Microwave-tomographic system for oil- and gas-multiphase-flow imaging

Since the early 1980s, a number of electrical imaging techniques based on capacitance, resistance, or inductance measurement at low frequencies have been developed for the monitoring of industrial processes, such as oil- and gas-multiphase flows. In principle, microwave tomography would produce higher resolution images than these low-frequency techniques. But it has mainly been studied for medical applications over the past two decades and is less developed for industrial applications. In this paper, the development of an experimental microwave-tomography system intended for oil- and gas-flow measurements is described, which includes the hardware for data acquisition and the numerical algorithm for image reconstruction. The investigation of the system for the imaging of static?dielectric phantoms modelling oil- and gas-flow distributions is reported together with the images obtained at two different microwave frequencies: 2.5 GHz and 4 GHz. It has been demonstrated that images of the dielectric phantoms can be reconstructed using the system, with the images obtained at 4 GHz having better quality and higher resolution.