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1
Okna, drzwi i bramy dla „inteligentnego domu”. Cz.2
Sieberath U., Benitz-Wildenburg J., Huber W., Schmidt A.
Świat Szkła
|
2018
|
R. 23, nr 4
50, 52--53
2
Okna, drzwi i bramy dla „inteligentnego domu”. Cz.1
Sieberath U., Benitz-Wildenburg J., Huber W., Schmidt A.
Świat Szkła
|
2018
|
R. 23, nr 3
10--16
3
Content available Measurement of impulse response of shallow water communication channel by correlation method
Schmidt J., Kochańska I., Schmidt A.
Hydroacoustics
|
2017
|
Vol. 20
149--158
EN
Performances of underwater acoustic communication (UAC) systems are strongly related to specific propagation conditions of the underwater channel; conditions that can additionally change in time due to the movement of the acoustic system transmitter and receiver or to reflection by underwater objects of the transmitted signal. The time-varying impulse response is a comprehensive description of dynamically changing transmission properties of the UAC channel. It is a basis for estimation of stochastic parameters used for designing the signaling scheme of the communication system. The paper presents the results of a measurement experiment conducted in a shallow water environment. The channel impulse response was measured by the correlation method with the use of two kinds of broadband signals: pseudo-random binary sequence (PRBS) and hyperbolic frequency modulation chirp (HFM). For each measurement result statistical transmission parameters, namely delay spread, Doppler spread, coherence time, and coherence bandwidth were estimated.
4
Content available Efficient RGB-D data processing for feature-based self-localization of mobile robots
Kraft M., Nowicki M., Penne R., Schmidt A., Skrzypczyński P.
International Journal of Applied Mathematics and Computer Science
|
2016
|
Vol. 26, no. 1
63--79
EN
The problem of position and orientation estimation for an active vision sensor that moves with respect to the full six degrees of freedom is considered. The proposed approach is based on point features extracted from RGB-D data. This work focuses on efficient point feature extraction algorithms and on methods for the management of a set of features in a single RGB-D data frame. While the fast, RGB-D-based visual odometry system described in this paper builds upon our previous results as to the general architecture, the important novel elements introduced here are aimed at improving the precision and robustness of the motion estimate computed from the matching point features of two RGB-D frames. Moreover, we demonstrate that the visual odometry system can serve as the front-end for a pose-based simultaneous localization and mapping solution. The proposed solutions are tested on publicly available data sets to ensure that the results are scientifically verifiable. The experimental results demonstrate gains due to the improved feature extraction and management mechanisms, whereas the performance of the whole navigation system compares favorably to results known from the literature.
5
Content available Digital microcontroller for sonar waveform generator
Schmidt A., Schmidt J.
Hydroacoustics
|
2016
|
Vol. 19
353--360
EN
Generating sounding signals is essential for the operation of active sonar. The system should be highly reliable. This can be achieved through architecture, communication between the devices, and a well-designed and self–testing software. The system presented in the article is responsible for the generation of hydroacoustic sounding signals, and ensures proper interaction between power amplifiers and power supplies. Thanks to its structure, the system ensures a very stable generation of many complex sounding signals in the form of linear or hyperbolic frequency modulated pulses (up or down), continuous transmission wave with increasing frequency and others. It is used in the mine-countermeasure sonar, but can also be used in other types of hydroacoustic systems which require complex sounding signals. The article describes possible technical solutions and sounding signals.
6
Projekt normy wyrobu dla drzwi wewnętrznych: prEN 14351-2 – stan prac
Schmidt A.
Świat Szkła
|
2015
|
R. 20, nr 5
27--29
7
Efektywne wykorzystanie danych RGB-D w systemie samolokalizacji na podstawie cech punktowych
Kraft M., Nowicki M., Schmidt A., Skrzypczyński P.
Prace Naukowe Politechniki Warszawskiej. Elektronika
|
2014
|
z. 194, t. 1
245--256
PL
Praca dotyczy zagadnienia określania położenia i orientacji sensora wizyjnego względem sześciu stopni swobody z wykorzystaniem cech punktowych wyodrębnionych z danych RGB-D. Skoncentrowano się na efektywnych algorytmach ekstrakcji cech w postaci punktów w przestrzeni trójwymiarowej oraz metodach zarządzania zbiorem cech otrzymanych z pojedynczego obrazu. Algorytmy i metody stanowiące główny wkład prezentowanej pracy w dziedzinę przetwarzania danych RGB-D przedstawiono w kontekście użycia w szybkim systemie odometrii wizyjnej. Przedstawiono wyniki badań eksperymentalnych wykorzystujących dwa publicznie dostępne zestawy danych RGB-D.
EN
This paper concerns the problem of a vision sensor's position and orientation computation with regard to the full six degrees of freedom, using point features extracted from RGB-D data. We focus on efficient point feature extraction algorithms and on methods for the feature set management in a single RGB-D data frame. While the fast, RGB-D-based visual odometry system described in this paper builds upon our previous results as to the general architecture, the important novel elements introduced here are aimed at improving the precision and robustness of the motion estimate computed from the matching point features of two RGB-D frames. The visual odometry system is tested on two publicly available data sets, demonstrating performance comparable to a much more complicated and computation intensive RGB-D SLAM method.
8
Content available The registration system for the evaluation of indoor visual slam and odometry algorithms
Schmidt A., Kraft M., Fularz M., Domagała Z.
Journal of Automation Mobile Robotics and Intelligent Systems
|
2013
|
Vol. 7, No. 2
46--51
EN
This paper presents the new benchmark data registra- tion system aimed at facilitating the development and evaluation of the visual odometry and SLAM algorithms. The WiFiBOT LAB V3 wheeled robot equipped with three cameras, XSENS MTi atitude and heading reference system (AHRS) and Hall encoders can be used to gather data in indoor exploration scenarios. The ground truth trajectory of the robot is obtained using the visual motion tracking system. Additional static cameras simulating the surveillance network, as well as artificial markers augmen ting the navigation are incorporated in the system. The datasets registered with the presented system will be freely available for research purposes.
9
Content available On augmenting the visual slam with direct orientation measurement using the 5-point algorithm
Schmidt A., Kraft A., Fularz M., Domagała Z.
Journal of Automation Mobile Robotics and Intelligent Systems
|
2013
|
Vol. 7, No. 1
5--10
EN
This paper presents the attempt to merge two paradigms of the visual robot navigation: Visual Simultaneous Localization and Mapping (VSLAM) and Visual Odometry (VO). The VSLAM was augmented with the direct, visual measurement of the robot orientation change using the 5-point algorithm. The extended movement model of the robot was proposed and additional measurements were introduced to the SLAM system. The efficiency of the 5-point and 8-point algorithms was compared. The augmented system was compared with the state of the art VSLAM solution and the proposed modification allowed to reduce the tracking error by over 30%.
10
Content available Comparative assessment of point feature detectors in the context of robot navigation
Schmidt A., Kraft M., Fularz M., Domagała Z.
Journal of Automation Mobile Robotics and Intelligent Systems
|
2013
|
Vol. 7, No. 1
11--20
EN
This paper presents evaluation of various contemporary interest point detector and descriptor pairs in the context of robot navigation. The robustness of the detectors and descriptors is assessed using publicly available datasets: the first gathered from the camera mounted on the industrial robot [17] and the second gathered from the mobile robot [20]. The most efficient detectors and descriptors for the visual robot navigation are selected.
11
Content available Implementation of the digital receiver in multibeam long-range sonar
Schmidt J., Schmidt A.
Hydroacoustics
|
2013
|
Vol. 16
203--210
EN
The article presents the implementation of a digital receiver in multibeam long-range sonar. Developed by the authors of the article, the implementation was part of sonar modernisation on large Polish Navy ships. The article explains the structure of the receiver, its design details and requirements affecting the architecture. The technical solutions regarding the equipment and signal processing algorithms for determining receiving beams for the active and passive mode are discussed. Key to the receiver design is the signal processing module responsible for determining the multibeam spatial filter (beamformer). Aspects of modern data transmission as used in the device are also discussed.
12
Content available Acoustic processor of the MCM sonar
Rudnicki M., Schmidt J., Schmidt A., Leśniak W.
Automatyka / Automatics
|
2013
|
Vol. 17, no. 1
73--82
EN
This paper presents the concept of an acoustic processor of the mine countermeasure sonar. Developed at the Department of Marine Electronics Systems, Gdańsk University of Technology, the acoustic processor is an element of the MG-89, a modernised underwater acoustic station. The focus of the article is on the modules of the processor. They are responsible for sampling analogue signals and implementing the algorithms controlling the measurement cycle and digital signal processing. As it performs the above funetions, the device should be highly reliable and resistant to mechanical and weather conditions and ensure a user friendly operation. The functions of the processor software should help with object detection and classification. In addition to these properties, the acoustic processor should operate in real time. The results of measurements should be displayed with the shortest possible delay in relation to sounding signals to allow the operator to take decisions ąuickly and establish if the object poses a risk.
PL
W artykule przedstawiono koncepcję procesora akustycznego sonaru MCM (ang. Mine Countermeasure Sonar), opracowaną i zrealizowaną w Katedrze Systemów Elektroniki Morskiej Politechniki Gdańskiej. Opisany procesor akustyczny jest elementem zmodernizowanej stacji hydrolokacyjnej MG-89. Zwrócono szczególną uwagę na moduły procesora, które odpowiadają za proces próbkowania sygnałów analogowych oraz realizują algorytmy sterowania cyklem pomiarowym i cyfrowego przetwarzania sygnałów. Urządzenie to przy wykonywaniu wyżej wymienionych funkcji powinno cechować się dużą niezawodnością oraz odpornością na narażenia mechaniczne i klimatyczne, a z punktu widzenia operatora - łatwością obsługi. Oprogramowanie procesora powinno zawierać funkcje ułatwiające detekcję i klasyfikację wykrytych obiektów. Poza wymienionymi właściwościami procesor akustyczny powinien również być systemem czasu rzeczywistego. Wyniki pomiarów powinny pojawiać się na zobrazowaniu z możliwie najmniejszym opóźnieniem, w stosunku do sygnałów sondujących, tak aby operator systemu mógł, w jak najkrótszym czasie, podjąć decyzję, czy wykryty obiekt jest niebezpieczny.
13
Content available Sprzętowy układ do estymacji siły oraz zmęczenia mięśni na podstawie sygnału elektromiograficznego
Kraft M., Fularz M., Kaczmarek P., Schmidt A.
Pomiary Automatyka Kontrola
|
2012
|
R. 58, nr 7
684-686
PL
W pracy przedstawiono implementację układu służącego do estymacji siły oraz zmęczenia mięśni na podstawie sygnału elektromiograficznego (EMG), rejestrowanego za pomocą dwukanałowego wzmacniacza, oraz położenia stawu mierzonego za pomocą enkodera kwadraturowego. W matrycy FPGA zaimplementowano struktury obliczające aktualną wartość średniej częstotliwości (MNF) oraz wartości średniokwadratowej (RMS) sygnału i kąta, co umożliwia estymację aktualnej siły oraz zmęczenia. Opracowane rozwiązanie jest skalowalne i umożliwia równoległą obsługę liczby kanałów ograniczonej wyłącznie zasobami matrycy FPGA.
EN
This paper presents an FPGA implementation of the muscle force and fatigue estimation unit based on the analysis of an electromyography (EMG) signal measured with a two-channel amplifier and the joint position measured with a quadratic encoder. The contemporary systems use the root mean square (RMS) of the EMG signal and muscle length to estimate the contraction force and decrease in the median frequency of the EMG signal to detect the muscle fatigue [2]. The proposed system consists of (Fig. 1): an infinite impulse response (IIR) high-pass filter with the cut-off frequency of 10 Hz, a dedicated RMS calculation block for the 512 samples window (Fig. 2.), the Fast Fourier Transform (FFT) block and a MicroBlaze processor. The muscle length is estimated using measurements from the encoder placed on the joint. The mean value of the EMG signal frequencies is used as the approximation of the median-frequency. The system was tested using the Xilinx SP605 evaluation kit and the obtained results were verified. The resources usage is presented in Table 1. Due to the FPGA inherent ability to parallelize computation, additional measurement channels can be easily added without increase in the processing time. The presented system is portable and can be used as a part of any mobile solution requiring feedback from the muscles-state (e.g. exoskeleton). Due to its scalability, it can be easily extended into a larger muscle-analysis system. Moreover, it can be modified to facilitate analysis of other biomedical signals.
14
Content available Acoustic processor of the mine countermeasures sonar
Rudnicki M., Schmidt J., Schmidt A., Leśniak W.
Hydroacoustics
|
2012
|
Vol. 15
179-186
EN
This paper presents the concept of an acoustic processor of the mine countermeasure sonar. Developed at the Department of Marine Electronics Systems, Gdansk University of Technology, the acoustic processor is an element of the MG-89, an underwater acoustic station. The focus of the article is on the modules of the processor. They are responsible for sampling analogue signals and implementing the algorithms controlling the measurement cycle and digital signal processing. As it performs the above functions, the device should be highly reliable and resistant to mechanical and weather conditions and ensure a user friendly operation. The functions of the processor software should help with object detection and classification. The results of measurements should be displayed with the shortest possible delay in relation to sounding signals to allow the operator to take decisions quickly and establish if the object poses a risk. The article demonstrates that the acoustic processor designed for and used by the Navy meets these requirements.
15
Content available Doppler effect in the cw fm sonar
Marszal J., Salamon R., Zachariasz K., Schmidt A.
Hydroacoustics
|
2011
|
Vol. 14
157-164
EN
When sonars are used for military purposes they have to ensure unobtrusive operation, afeature that can be potentially secured by ‘silent sonars’ or continuous wave frequency modulation sonars (CW FM sonars). The article presents how these sonars operate and identifies the relations between their parameters. The Doppler effect and its impact on the CW FM sonar are studied to identify how it affects the sonar’s parameters. The results of simplified theoretical calculations are supported with results of computer simulations of a more realistic model.
16
Content available Workstation for training ASW helicopter navigators and analysing real flight data
Raganowicz A., Kilian L., Marszal J., Schmidt A., Sidorko T., Rudnicki M.
Hydroacoustics
|
2009
|
Vol. 12
181-188
EN
The article presents a training and diagnostic workstation designed for Polish Navy ASW helicopter navigators. Installed at the helicopter base, the workstation is used for training and instruction in operating the device and analysing information gathered by navigators during the flight using the ASW onboard sonar, sonobuoy receiver and magnetometer. The workstation allows instructors to task two operators and monitor their performance under conditions resembling those onboard a plane. The tasks involve the operation of the consoles and collecting information during tactical situations, diagnosing damage and analysing flight data in office environment. The objective is to ensure proper helicopter navigator training and experience given the limited possibility of training flights.
17
Content available Bearing errors in passive sonar stationary target location
Schmidt A., Marszal J., Salamon R., Jedel A., Ostrowski Z.
Hydroacoustics
|
2009
|
Vol. 12
189-200
EN
The paper presents a method for determining the coordinates of stationary targets using passive sonar bearing. It identifies the requirements sonar movements must meet to keep the incorrect determination of coordinates to a minimum. It gives the relations, which help determine coordinate errors analytically. Numerical experiments are used to demonstrate the success of the analysis.
18
Szybki i wiarygodny system automatycznego rozpoznawania twarzy opisanych deformowalnymi modelami kształtu
Schmidt A., Kasiński A.
Prace Naukowe Politechniki Warszawskiej. Elektronika
|
2008
|
z. 166, t. 1
81-90
PL
W artykule przedstawiony został system automatycznego rozpoznawania twarzy wykorzystujący deformowalne modele kształtu. Do wykrywania twarzy i oczu wykorzystano nowoczesne Kaskadowe Detektory Haara. Ekstrakcja reprezentacji konturowej twarzy została zrealizowana za pomocą dwóch modeli: Aktywnych Kształtów i Bayesowskich Kształtów Stycznych. Klasyfikacja jest realizowana za pomocą trzech rodzajów klasyfikatorów bayesowskich. Opracowany system osiągnął wysoką skuteczność rozpoznawania, a jego wydajność obliczeniowa umożliwia wykorzystanie w czasie rzeczywistym.
EN
In this paper we present an automatic face recognition system using deformable shape models as face descriptors. The state of the art Haar Cascade Classifiers were used to detect faces and eyes. Face contours were extracted with two different models: the Active Shape Model and the Bayesian Tangent Shape Model. The efficiency of three different bayesian classifiers was evaluated. The proposed system achieved high recognition rate, while keeping the processing time low enough to be used in a real-time.
19
Content available remote The put face database
Kasiński A., Florek A., Schmidt A.
Image Processing & Communications
|
2008
|
Vol. 13, no 3-4
59-64
EN
In this paper we present a new database of color, high resolution face images. The database contains almost 10000 images of 100 people acquired in partially controlled conditions and stored in 2048 x 1536 pixels images. The base is publicly available for research purposes and can be used as a training and testing material in developing various algorithms related to the face detection, recognition and analysis.
20
Content available High accuracy hydroacoustic system to study codend model parameters
Marszal J., Schmidt J., Jedel A., Schmidt A., Wojan Z., Zachariasz K., Leśniak W.
Hydroacoustics
|
2008
|
Vol. 11
271-278
EN
An important task of fishing gear designers is to develop effective selective fishing gears by optimizing its geometry. The high accuracy hydroacoustic system for codend geometry measurements was designed for developing the construction of cod codend for the Baltic fishery. The system consists of 10 pairs of hydrophones, measuring microprocessor device and notebook computer. The high frequency short pulse excitation combined with the matched digital filtering make it possible to obtain high resolution of measure data. Additionally the thermistors mounted in the hydrophones are used to calculate the local sound velocity and enable precision calibration of obtained measuring data. The construction solutions, the measuring procedure and examples of obtained data are presented below.
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