ITT-5.1

Application of a Brightness-Adapted Edge Detector for Real-Time Railroad Tie Detection in Video Images
Joerg Velten, Anton Kummert (Laboratory for Communication Theory, Department of Electrical Engineering, University of Wuppertal FB13, 42097 Wuppertal, Germany), Dirk Maiwald (STN ATLAS Elektronik GmbH)

Due to the increasing calculation power of dedicated hardware, real-time image processing becomes practicable at reasonable expenses. Nevertheless the algorithms concerned have to be adapted to real-time requirements. The subject treated in this paper is tie detection for automated railway inspection. An edge detector is proposed in which the sensitivity is adaptable to the local brightness of the processed image. The required effort is the performance of a convolution operation with subsequent decision concerning the sign of the values obtained.

ITT-5.2

Improved Knock Detection by Time Variant Filtered Structure-Borne Sound
Sönke Carstens-Behrens, Michael Wagner, Johann F Böhme (Ruhr University Bochum, Department of Electrical Engineering, D-44780 Bochum, Germany)

In order to detect knock in spark ignition engines generally structure--borne sound signals measured by acceleration sensors mounted on the engine housing are used. At test bed engines additional pressure sensors measuring the pressure inside the combustion chamber deliver a reference signal to adjust the parameters of knock detection based on the sound signal. We show by experimental results that the approximation of pressure signals by time variant filtering of structure--borne sound increases the performance of knock detection significantly. These results can be regarded as an upper bound of what can be achieved by knock detectors with less computational load.

ITT-5.3

Speech-Enabled Information Retrieval in the Automobile Environment
Yeshwant K Muthusamy, Rajeev Agarwal, Yifan Gong, Vishu R Viswanathan (DSP Solutions R&D Center, Texas Instruments)

With recent advances in speech recognition and wireless communications, the possibilities for information access in the automobile have expanded significantly. In this paper, we describe four system prototypes for (i) voice-dialing, (ii) Internet information retrieval---called InfoPhone, (iii) voice e-mail, and (iv) car navigation. These systems are designed primarily for hands-busy, eyes-busy conditions, use speaker-independent speech recognizers, and can be used with a restricted display or no display at all. The voice-dialing prototype incorporates our hands-free speech recognition engine that is very robust in noisy car environments (~1% WER and 3% string error rate on the continuous digit recognition task at 0 db SNR). The InfoPhone, voice e-mail, and car navigation prototypes use a client-server architecture with the client designed to be resident on a phone or other hand-held device.

ITT-5.4

A DSP Active Filter For Power Conditioning
Abdurrahman Unsal, Annette R von Jouanne, Virginia L Stonick (ECE Dept, Oregon State University)

ABSTRACT This paper presents a DSP controlled active filter for power conditioning. The active filter is designed to cancel lower order harmonics generated by nonlinear loads using a series resonant LC tank tuned to a high frequency along with a pulse-width modulation (PWM) rectifier topology. The PWM control of the active filter allows for independent control of lower order harmonics, both in amplitude and in phase, to efficiently cancel load generated harmonics for power quality improvement. The active filter control algorithm is simulated in Matlab and the harmonic cancellation process is verified through PSpice.

ITT-5.5

Fourier and Wavelet Transform Features for Whirl Tower Diagnostics
Scott Fornero, N. Kehtarnavaz (Texas A&M University, Department of Electrical Engineering), M. Swaminadham (Texas A&M University, Department of Engineering Technology and Industrial Distribution), Don A Phillips (Texas A&M University, Department of Industrial Engineering)

This paper describes the application of signal processing methods to extract key features for detection and prediction of faults in rotating mechanical components of a whirl tower test facility. Procedures will be described for processing the vibration signals from critical components of the whirl tower using the Fourier transform and the wavelet transform. The wavelet transform provides localization of signals in both time and frequency, revealing data that is averaged out in the Fourier analysis. The features extraction processes described are based on specific knowledge of the whirl tower equipment. The real-time analysis discussed will allow for scheduling of inspection, repair, or replacement of failed and degraded components with minimal impact on production.

ITT-5.6

An Industrial Application of Signal Processing: Ceramic Microcrack Detection
Ramón Miralles, Juan Morales, Luis Vergara (Dpto. Comunicaciones. Universidad Politecnica de Valencia)

On line quality control in industrial plants is an open field for signal processing applications. In this paper we present a real-time prototype for the detection of microcracks in tiles of wet ceramic by means of ultrasonics. We also describe the signal processing algorithm applied and particularly how the false alarm probability (PFA) may be controlled. Finally an experimental test shows the agreement between the predicted PFA and the measured one, thus giving practical applicability to the proposed method.

ITT-5.7

Application of Ground Penetrating Radar for Coal Depth Measurement
Jonathon C Ralston, David W Hainsworth (CSIRO, Exploration and Mining)

This paper describes the development of a new ground penetrating radar system for measuring coal thickness in underground mining operations. Although subsurface radar exhibits significant potential for depth measurement, the raw signals are complicated and cannot be readily interpreted by mining personnel. We show how real-time signal digital processing plays a key role in transforming the raw radar signals into a form that can be readily understood. We also indicate some of the unique challenges encountered when implementing a radar processing system in a harsh underground mining environment.

ITT-5.8

CONTROL-ORIENTED IDENTIFICATION AND UNCERTAINTY ESTIMATION FOR PAPER MACHINES
Alf Green (Honeywell-Measurex), Kostas Tsakalis (Arizona State University), Ward MacArthur (Honeywell-Hi-Spec Solutions), Sachi Dash (Honeywell Technology Center-Phoenix)

A control-oriented identification and uncertainty estimation approach from input-output data is presented, for use in the design of control systems for paper machines. The application of this approach is demonstrated on a high fidelity simulator. An estimate of the process model along with the uncertainty bounds that describe the confidence limits of the model, consistent with the robust control theory, is obtained. These results can then used to design a multivariable controller based on loop-shaping principles and guided by the estimated uncertainty bounds. The simulations demonstrate the suitability of the approach and illustrate that the technique can be used to provide high bandwidth performance for both servo and regulatory control.

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Last Update: February 4, 1999 Ingo Höntsch