Tamas Daboczi

Tamas Daboczi
Budapest University of Technology and Economics · Department of Measurement and Information Systems

Dr. habil, CSc, PhD

About

44
Publications
9,755
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
294
Citations
Additional affiliations
September 1996 - present
Budapest University of Technology and Economics
Position
  • Head of Dept., Associate professor

Publications

Publications (44)
Article
Full-text available
Matched filtering is a well-known method frequently used in digital signal processing to detect the presence of a pattern in a signal. In this paper, we suggest a time variant matched filter, which, unlike a regular matched filter, maintains a given alignment between the input signal and the template carrying the pattern, and can be realized recurs...
Article
Full-text available
We present a resource-efficient frequency adaptation method to complement the Fourier analyzer proposed by Péceli. The novel frequency adaptation scheme is based on the adaptive Fourier analyzer suggested by Nagy. The frequency adaptation method was elaborated with a view to realizing a detector connectivity check on an FPGA in a new beam loss moni...
Article
Full-text available
In this paper, three- and four-parameter least squares (LS) sine fitting algorithms are investigated. It is pointed out that the three-parameter fitting is well conditioned in its standard form, both for short and long records. Then, the conditioning of the four-parameter fitting (4PF) is investigated. A scaling factor is derived in order to ensure...
Article
Beam loss monitoring (BLM) is a method widely used for machine setup and tuning at particle accelerators, e.g. in physics research and medical applications. Additionally, the higher the energy and intensity of the particle beams, the more important the role of the BLM system in machine protection, which becomes critical for machines employing super...
Article
Deconvolution (or inverse filtering) is applied if a time, space, or other domain signal is distorted by a measurement system and one wants to reconstruct the signal to be measured. This is an estimation process since the measurement is always corrupted by noise. The estimation problem is usually ill posed, meaning that even very slight changes in...
Article
Marker-based optical position measurement is investigated in this paper. If the exposure time is not very short, it might cause the blur of the marker on the image if fast movement needs to be recorded. This paper investigates the effect of blur on the center point estimate and provides a measure for the distortion to help adjust camera parameters...
Article
Full-text available
The FIRST/IoT project coordinated by the Faculty of Informatics, University of Debrecen, Hungary has important impact on the R&D work in this field. Six activity areas have been covered in the twenty-seven months long project. More than thirty researchers from half dozen Hungarian and other universities and research institutes have been involved in...
Conference Paper
The proposed applications of Internet of Things (IoT) are abundant (smart buildings, smart cities, smart infrastructure, vehicle to vehicle, vehicle to road communications, smart utilities, wearable computing, etc.). However, the construction and operation (Constructability and Operability) of such large scale distributed embedded systems are not s...
Article
A common method to test analog-to-digital converters (ADCs) is sine fitting. If a very large set of samples needs to be processed (long records), the iterative four-parameter sine fit algorithm is very sensitive to the initial estimate of the fundamental frequency. Even a slight error in the initial guess can spoil the fit because of the several lo...
Conference Paper
Testing Analog-to-Digital Converters is important for both the manufacturer and the consumer. One of the test procedures require to excite the ADC with a pure sine wave, and calculate the errors (SINAD, SNR, ENOB, THD+N etc.) of the Device Under Test from the acquired signal. The error definitions are based on the difference between the reference s...
Article
A common method to test AD converters is the sine fitting. If very large dataset needs to be processed (long records), the iterative four parameter sine fit algorithm is very sensitive to the initial value of the fundamental frequency estimator. Even a very slight error in the initial guess can spoil the fit because of the local minima in the error...
Article
In this paper, several methods are presented to fully calibrate a stereo vision system for far-range outdoor applications. Traditionally, intrinsic camera parameters are determined from a high number of feature points, while pose estimation is solved with a few (tens). Close-range setups are not well suited for far-range applications, while far-ran...
Article
Full-text available
This paper presents a method for calculating the accurate inclination angle of a balancing robot using accelerometers and optionally angular rate sensor (rate gyroscope), based on systematic correction of sensor errors. The correction is calculated on the basis of physical model of the system. The basic idea of accelerometer-based inclination measu...
Conference Paper
Full-text available
Industrial applications, especially automotive ones should be robust and cheap. Both properties can be improved by using model based state estimation. Sensor cost can be reduced if some signal values are calculated from the other, already measured signals or the robustness of the system can be increased by supervising the sensors by calculating the...
Conference Paper
Full-text available
This paper is the second presented in this conference dealing with permanent magnet synchronous machine model identification. Main purpose of the research introduced in this paper, besides to introduce a new parameter estimation method, was to investigate the cost function properties. Understanding shape and behaviour of the cost function helps the...
Chapter
Full-text available
This work was supported by the Hungarian National Office for Research and Technology through the project "Advanced Vehicles and Vehicle Control Knowledge Center" (OMFB01418/2004) which is gratefully acknowledged.
Conference Paper
Full-text available
This paper reports advances in model based machine torque estimation used in electronic power assisted steering systems. Using machine input voltages the permanent magnet synchronous machine internal states and the output torque can be estimated. This technique can be used to detect machine failures and also can be used to verify the failure of the...
Conference Paper
Full-text available
This paper reports advances in sensorless rotor position estimation in motor control of electronic power assisted steering systems (EPAS). A systematic calculation error was discovered in the INFORM - a saliency based sensorless rotor position estimation method, - when it was applied to permanent magnet synchronous machines (PMSMs). A solution was...
Conference Paper
A far-range camera calibration method for vision sensors used in automatic lane detection systems is investigated. Autonomous vehicle guidance based on stereo image acquisition requires the knowledge of the camera parameters, such as camera position, orientation, lens distortion, focal length etc. with high precision. Calibration is performed by pl...
Conference Paper
Full-text available
The paper presented a DSP-based electromagnetic flowmeter. There are 4 pairs of electrodes and a pressure sensor for effective flowrate measurement in partially filled pipes. Although this setup is able to measure different flow profiles, our development focused on the improvement of measurement accuracy by signal processing methods. A sinusoidal e...
Conference Paper
Full-text available
Inverse filtering of time domain signals is investigated. Inverse filtering requires the knowledge of the transfer function of the measurement system, which can be estimated on the base of measurements (system identification). The quality of the system identification influences the quality of the signal reconstruction. We investigate the influence...
Conference Paper
Full-text available
This paper reports advances in the design and development of decoupling method in motor control of electric power assisted steering (EPAS) systems. A motor model for permanent magnet synchronous machines (PMSM) is described. Implementation details, simulation and measurement results are also presented
Article
An approach for automatically testing GUIs in the MATLAB environment has been proposed. We developed a software tool that tests GUIs by simulating the user through an action recorder. We proposed a heuristic test procedure: providing random input to GUI, but guiding the randomness with predefined weights assigned to the user controls. The weights c...
Article
Full-text available
A signal distorted by a system having static, invertible, nonlinear characteristics can be exactly restored in the absence of noise. In this case, the inverse of the characteristics can be used. When noise is superimposed to the distorted signal, the inverse characteristics may not be proper because the noise is strongly amplified. This noise has t...
Conference Paper
Full-text available
When a signal passes a system having a static, nonlinear transfer function, the output signal will be distorted. In addition to it, the defected output signal is usually contaminated by noise, due to the noisy environment. If the distortion level of the signal is not acceptable, we have to compensate it. This should be done carefully, because an im...
Conference Paper
Full-text available
When a signal goes through a system having a static, nonlinear transfer function, the output signal will be distorted. In addition, the detected output signal is usually contaminated by noise, due to the noisy environment. If we compensate the nonlinearity with its inverse, the expected value of the output signal will be different from it's origina...
Article
Full-text available
In this paper a robust and efficient method is presented for restoration of nonlinearly distorted movie soundtracks. The method is based on the a priori knowledge of the shape of the nonlinear function, which is assumed to be a static nonlinearity. The original undistorted signal is modeled by a set of harmonically related sinusoids. This signal is...
Article
Full-text available
The quality of images is limited by the performance of the optical system used. The imperfections of the optical system cause distortion of the image. If the distortion is known it can be (partly) compensated. This procedure is called inverse filtering. The problem is, however, ill-posed, which means that the measurement noise is amplified by the i...
Conference Paper
Full-text available
A signal distorted by static, invertible, nonlinear characteristics can be exactly restored in the absence of noise. In this case the inverse of the characteristics can be used. When noise is superimposed to the distorted signal, the inverse characteristics may not be proper, because the noise is strongly amplified. This noise has to be suppressed...
Article
The quality of images are limited by the performance of the optical system used. The imperfection of the optical system cause distortion of the image. If the distortion is known it can be (partly) compensated. This procedure is called inverse filtering. The problem is, however, ill-posed, which means that the measurement noise is amplified by the i...
Article
Full-text available
Time domain measurements are distorted by the measurement system if the bandwidth of the system is not sufficiently high compared to that of the signal to be measured. If the distortion is known the measured signal can be compensated for it (inverse filtering or deconvolution). Since the measurement is always corrupted by noise, the reconstruction...
Article
Full-text available
A system is described for calibrating high-bandwidth oscilloscopes using pulse signals. The fast-pulse oscilloscope calibration system (FPOCS) is to be used to determine the step response parameters for digitizing oscilloscopes having bandwidths of ~20 GHz. The system can provide measurement traceability to standards maintained at the U.S. National...
Article
Full-text available
Nonparametric identification of linear systems is investigated in this paper. Nonparametric identification is the estimation of the time record of the impulse response of the system. It is a deconvolution problem, i.e., inverse operation of the convolution of the impulse response and the excitation signal. The problem is ill posed, i.e., deconvolut...
Conference Paper
The FPOCS for traceable calibration of 20-GHz oscilloscope sampling channels using pulse signals, is described. It is PC-based and includes precision step generation hardware, novel algorithms for parameter estimation, timebase correction, reference step deconvolution, and uncertainty analyses. Preliminary tests show good agreement between the FPOC...
Conference Paper
Time domain measurements are distorted by the measurement system if the bandwidth of the system is not sufficiently high compared to that of the signal to be measured. If the distortion is known the measured signal can be compensated (inverse filtering or deconvolution). Since the measurement is always corrupted by noise the reconstruction is an es...
Conference Paper
Deconvolution of transient signals is investigated in this paper. Deconvolution is the inverse operation of convolution, i.e. restoration of a distortion caused by a linear system. The aim can be either to reconstruct the signal to be measured or to estimate the impulse response of the system. The problem is ill-posed, i.e. deconvolution amplifies...
Article
This paper investigates inverse filtering of transient signals. The problem is ill-conditioned, which means that a small uncertainty in the measurement causes large deviations in the reconstructed signal. This amplified noise has to be suppressed at the price of bias in the estimation. The most difficult task is to find the optimal degree of noise...
Article
Full-text available
Although very promising results have been achieved by oth-ers in producing reference disparity maps for real-world indoor scenes with uncalibrated structured light and engineered scenes, few papers emphasise that 3D-synthesis remains indispensable in generating ground-truth data up to numerical precision, and also for long-range stereo, to discrimi...
Article
Full-text available
This paper presents the design considerations of a modular hardware-software platform devoted to serve education, research and development in the fields of ambient intelligence, ubiquitous/pervasive computing, and networked embedded systems. The primary goal of this new platform is to support Embed-ded Information Systems Engineering education at t...
Article
Az OTKA támogatás fő célja a doktori értekezésekig eljuttatni az igéretes doktoranduszokat. A pojekt sikeres volt. Publikációs listák: http://www.mycite.omikk.bme.hu/search/index.php?phase=-1 Egyszerű keresés Név Honlapok nem publikált munkaanyagokkal elérhetők a publikációs listákból. Márkus János megvédte Bank Balázs megvédte Valyon József megvéd...

Network

Cited By