| 1. |
- Bengtsson, Lars, 1963
(författare)
-
RISC-baserad 50 MHz räknare med alfanumerisk display
- 1995
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Ingår i: Allt om elektronik. ; 6, s. 35-37
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Denna artikel presenterar en konstruktion som använder en RISC-kontroller (PIC16C54) som frekvensräknare. Frekvensen räknas på controllerns RTCC-ingång och signalfrekvensen, uttryckt i kHz visas på en alfanumerisk display.
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| 2. |
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| 3. |
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Larsson, Ulf, et al.
(författare)
-
Navigating an articulated vehicle and reversing with a trailer
- 1994
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Ingår i: Proceedings, 1994 IEEE International Conference on Robotics and Automation. - Los Alamitos, Calif : IEEE Computer Society Press. - 0818653302 ; , s. 2398-2404
-
Konferensbidrag (refereegranskat)abstract
- This paper describes two related tests; to navigate an articulated lawn mower and to reverse a mobile robot with a trailer. In both cases the vehicles are to follow a prespecified trajectory. The navigation principal is based on measured directions to several identical beacons, consisting of strips of reflective tapes. The angular sensor is a rotating laser for the illumination of the beacons and a highly sensitive electro-optical receiver for detecting the directions to the beacons. A Kalman filter is used to combine the measurements from the odometers with the detected angles to the known position of the beacons. To measure the angle between the robot and the trailer the same laser was used. This was done by placing two reflective beacons on the trailer. The repeatability was within 2 centimetre at low speed. The navigation of these two different types of vehicles turns out to be, essentially, the same problem. The sensitivities are different. Emphasis is on robust state estimation
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| 8. |
- Bengtsson, Lars, 1963
(författare)
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Generation and measurement of pulses and delays with RISC-controllers
- 1997
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Ingår i: Measurement Science and Technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 8, s. 679-683
-
Tidskriftsartikel (refereegranskat)abstract
- An instrument for the generation of pulses and delays has beendeveloped for applications in laserspectroscopy experiments. The pulses from achopped laserbeam are counted, and when a preset value is reached, two signalsare generated: one delayed trigger pulse with constant length and one delayed‘shutter pulse’ (referred to as the ‘shutter window’ below) which opens a light shutterand allows one light pulse to enter the experimental region and excite the sample.The delays of the trigger pulse and the shutter window and the width of the shutterwindow can all be set independently to any value from 0 up to 50 ms with 0.05 mssteps. A separate microcontroller measures the width of the shutter window with anaccuracy of 1micro seconds. The pulse delays and the width of the shutter window are setwith thumbwheel potentiometers connected as voltage dividers. A microcontrollerreads the set values with a four-channel, 12-bit AD converter. This techniquesaves a lot of hardware wiring as well as software writing when compared to thealternative of using separate, BCD-coded thumbwheels for each timesetting.In total, the instrument consists of two independent RISC-controllers: onePIC16C55 for counting chopper pulses and generating pulses and delays, and onePIC16C74 for measuring (and displaying) the width of the shutter window. Thewidth of the shutter window is measured with 1micro second resolution by taking fulladvantage of two different peripherial I/O devices in the PIC16C74: the 16-bit ‘inputcapture’ module and the external interrupt facility.
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| 9. |
- Ujvari, Sandor, 1972-, et al.
(författare)
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Simulation and emulation of sensor systems for intelligent vehicles
- 1998
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Ingår i: Mechatronics '98. - : Pergamon Press. - 0080433391 ; , s. 385-390
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Konferensbidrag (refereegranskat)abstract
- Simulation of sensor systems for mobile robots are described in this paper. By simulation of smart sensor systems, the performance of semi-autonomous vehicles / mobile robots can be enhanced. Smart sensor systems used in the field of mobile robotics can utilise adaptive algorithms. e. g. artificial neural nets, fuzzy logic or hybrid variants of these systems. The development, training and evaluation of adaptive algorithms for sensor systems can be done within a virtual environment in which graphical models are built to simulate an intelligent vehicle, its sensors, and its environment. The virtual sensors are validated by comparing the characteristics of the virtual sensors with those of the real devices.
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| 10. |
- Viberg, Mats, 1961, et al.
(författare)
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Maximum Likelihood Array Processing in Spatially Correlated Noise Fields Using Parameterized Signals
- 1997
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Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1941-0476 .- 1053-587X. ; 45, s. 996-1004
-
Tidskriftsartikel (refereegranskat)abstract
- This paper deals with the problem of estimating signal parameters using an array of sensors. This problem is of interest in a variety of applications, such as radar and sonar source localization. A vast number of estimation techniques have been proposed in the literature during the past two decades. Most of these can deliver consistent estimates only if the covariance matrix of the background noise is known. In many applications, the aforementioned assumption is unrealistic. Recently, a number of contributions have addressed the problem of signal parameter estimation in unknown noise environments based on various assumptions on the noise. Herein, a different approach is taken. We assume instead that the signals are partially known. The received signals are modeled as linear combinations of certain known basis functions. The exact maximum likelihood (ML) estimator for the problem at hand is derived, as well as a computationally more attractive approximation. The Cramer Rao lower bound (CRB) on the estimation error variance is also derived and found to coincide with the CRB, assuming an arbitrary deterministic model and known noise covariance.
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| 11. |
- Sobral, L., et al.
(författare)
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Ultrasonic Detection in Robotic Environments
- 1996
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Ingår i: Proceedings., 1996 IEEE International Conference on Robotics and Automation. - 0780329880 ; 1, s. 347-352
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Konferensbidrag (refereegranskat)abstract
- Based on information produced by a 200 kHz ultrasonic echo device developed for robotics and other industrial purposes, a method for object identification was developed and is presented in this paper. Interpretation of the echos from the reflecting objects, complexity analysis and information extraction were made by system identification methods such as impulse response analysis and state-space realization. A clustering-type discrimination of different objects based on the echo identification result was made in a subsequent step using the least-squares method. Experimental evaluation showed that the method is effective for object recognition
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| 12. |
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| 13. |
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| 14. |
- Andersson, Sören, et al.
(författare)
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Optimal Dimension Reduction for Array Processing : Generalized
- 1993
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This correspondence extends previously reported work [1, 2] on the problem, or rather possibility, of achieving optimality of beamspace (BS) array processing, where use is made of dimensionally reduced data vectors. The optimality here is with respect to the best possible element space (ESP) parameter estimation accuracy, i.e., the Cramér-Rao bound.
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| 15. |
- Homer, John, et al.
(författare)
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Improved LMS Estimation via Structural Detection
- 1995
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Ingår i: Information Theory, 1995. Proceedings., 1995 IEEE International Symposium on.
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In various adaptive estimation applications, the unknown channel is characterized by an impulse response which consists of extended regions of negligible response or `inactivity'. We consider the LMS estimation of a channel that may be well approximated by an FIR (filter) model with only a few nonzero tap coefficients within a given delay horizon or tap length n. When the number of nonzero tap coefficients m is small compared to the delay horizon n, the performance of the LMS estimator is greatly enhanced when this specific structure is exploited. We propose a consistent algorithm that performs identification of nonzero taps only
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| 16. |
- Ottersten, Björn, 1961-, et al.
(författare)
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Analysis of Subspace Fitting and ML Techniques for Parameter Estimation from Sensor Array Data
- 1992
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Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-587X .- 1941-0476. ; 40:3, s. 590-600
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Tidskriftsartikel (refereegranskat)abstract
- It is shown that the multidimensional signal subspace method, termed weighted subspace fitting (WSF), is asymptotically efficient. This results in a novel, compact matrix expression for the Cramer-Rao bound (CRB) on the estimation error variance. The asymptotic analysis of the maximum likelihood (ML) and WSF methods is extended to deterministic emitter signals. The asymptotic properties of the estimates for this case are shown to be identical to the Gaussian emitter signal case, i.e. independent of the actual signal waveforms. Conclusions concerning the modeling aspect of the sensor array problem are drawn.
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| 17. |
- Ottersten, Björn, 1961-, et al.
(författare)
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Performance Analysis of the Total Least Squares ESPRIT Algorithm
- 1991
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Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-587X .- 1941-0476. ; 39:5, s. 1122-1135
-
Tidskriftsartikel (refereegranskat)abstract
- The asymptotic distribution of the estimation error for the total least squares (TLS) version of ESPRIT is derived. The application to a uniform linear array is treated in some detail, and a generalization of ESPRIT to include row weighting is discussed. The Cramer-Rao bound (CRB) for the ESPRIT problem formulation is derived and found to coincide with the asymptotic variance of the TLS ESPRIT estimates through numerical examples. A comparison of this method to least squares ESPRIT, MUSIC, and Root-MUSIC as well as to the CRB for a calibrated array is also presented. TLS ESPRIT is found to be competitive with the other methods, and the performance is close to the calibrated CRB for many cases of practical interest. For highly correlated signals, however, the performance deviates significantly from the calibrated CRB. Simulations are included to illustrate the applicability of the theoretical results to a finite number of data.
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| 18. |
- Ottersten, Björn, 1961-, et al.
(författare)
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Robust Source Localization Based on Local Array Response Modeling
- 1992
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Ingår i: Proceedings of the 1992 IEEE International Conference on Acoustics, Speech and Signal Processing. - Linköping : IEEE. - 0780305329 ; , s. 441-444 vol.2
-
Konferensbidrag (refereegranskat)abstract
- Many practical applications of signal processing require accurate determination of signal parameters from sensor array measurements. Most estimation techniques are sensitive to errors in the array response model. Thus, reliable array calibration schemes are of great importance. A paradigm for generating an array model from noise corrupted calibration vectors is developed. The key idea is to use a local parametric model of the sensor responses. The potential improvement using the suggested scheme is demonstrated on real data collected from a full-scale hydroacoustic array.
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| 19. |
- Peterson, Bo
(författare)
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Induction Machine Speed Estimation - Observations on Observers
- 1996
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This work focuses on observers estimating flux linkage and speed for induction machines, mainly in the low speed region. With speed estimation, sensorless control is possible, meaning that the speed of induction machines without mechanical speed sensors can be controlled. The observer based sensorless drive system has superior dynamic performance compared to a system with an open loop frequency inverter, yet it is neither more complex nor expensive. Using mechanical equivalent models of the induction machine and observers, an accurate flux observer working in the entire speed region of the induction machine is presented. The flux observer is expanded into a combined flux and speed observer, measuring only stator current and voltage. A method for sensorless control is proposed, analyzed and experimentally verified. Observer and controller calculations are performed by a digital signal processor.
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| 20. |
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| 21. |
- Samuelsson, Olof
(författare)
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Power System Damping - Structural Aspects of Controlling Active Power
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Environmental and economical aspects make it difficult to build new power lines and to reinforce existing ones. The continued growth in demand for electric power must therefore to a great extent be met by increased loading of available lines. A consequence is that power system damping is reduced, leading to a risk of poorly damped power oscillations between the generators. This thesis proposes the use of controlled active loads to increase damping of such electro-mechanical oscillations. The focus is on structural aspects of controller interaction and of sensor and actuator placement. On-off control based on machine frequency in a single machine infinite bus system is analysed using energy function analysis and phase plane plots. An on-off controller with estimated machine frequency as input has been implemented. At a field test it damped oscillations of a 0.9 MW hydro power generator by controlling a 20 kW load. The linear analysis uses two power system models with three and twenty-three machines respectively. Each damper has active power as output and local bus frequency or machine frequency as input. The power system simulator EUROSTAG is used both for generation of the linearized models and for time simulations. Measures of active power mode controllability and phase angle mode observability are obtained from the eigenvectors of the differential-algebraic models. The geographical variation in the network of these quantities is illustrated using the resemblance to bending modes of flexible mechanical structures. Eigenvalue sensitivities are used to determine suitable damper locations. A spring-mass equivalent to an inter-area mode provides analytical expressions, that together with the concept of impedance matching explain the structural behaviour of the power systems. For large gains this is investigated using root locus plots. The effect of using two dampers is studied. For the three machine system this is done for all combinations of the two gains in a certain range. In the twenty-three machine case one gain takes only two values as the other is varied.
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| 22. |
- Swindlehurst, A. Lee, et al.
(författare)
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Multiple Invariance ESPRIT
- 1992
-
Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-587X .- 1941-0476. ; 40:4, s. 867-881
-
Tidskriftsartikel (refereegranskat)abstract
- A subspace-fitting formulation of the ESPRIT problem is presented that provides a framework for extending the algorithm to exploit arrays with multiple invariances. In particular, a multiple invariance (MI) ESPRIT algorithm is developed and the asymptotic distribution of the estimates is obtained. Simulations are conducted to verify the analysis and to compare the performance of MI ESPRIT with that of several other approaches. The excellent quality of the MI ESPRIT estimates is explained by recent results which state that, under certain conditions, subspace-fitting methods of this type are asymptotically efficient.
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| 23. |
- Viberg, Mats, et al.
(författare)
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Detection and Estimation in Sensor Arrays using Weighted Subspace Fitting
- 1991
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Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-587X .- 1941-0476. ; 39:11, s. 2436-2449
-
Tidskriftsartikel (refereegranskat)abstract
- The problem of signal parameter estimation of narrowband emitter signals impinging on an array of sensors is addressed. A multidimensional estimation procedure that applies to arbitrary array structures and signal correlation is proposed. The method is based on the recently introduced weighted subspace fitting (WSF) criterion and includes schemes for both detecting the number of sources and estimating the signal parameters. A Gauss-Newton-type method is presented for solving the multidimensional WSF and maximum-likelihood optimization problems. The global and local properties of the search procedure are investigated through computer simulations. Most methods require knowledge of the number of coherent/noncoherent signals present. A scheme for consistently estimating this is proposed based on an asymptotic analysis of the WSF cost function. The performance of the detection scheme is also investigated through simulations.
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| 24. |
- Viberg, Mats, et al.
(författare)
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Sensor Array Processing Based on Subspace Fitting
- 1991
-
Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-587X .- 1941-0476. ; 39:5, s. 1110-1121
-
Tidskriftsartikel (refereegranskat)abstract
- Algorithms for estimating unknown signal parameters from the measured output of a sensor array are considered in connection with the subspace fitting problem. The methods considered are the deterministic maximum likelihood method (ML), ESPRIT, and a recently proposed multidimensional signal subspace method. These methods are formulated in a subspace-fitting-based framework, which provides insight into their algebraic and asymptotic relations. It is shown that by introducing a specific weighting matrix, the multidimensional signal subspace method can achieve the same asymptotic properties as the ML method. The asymptotic distribution of the estimation error is derived for a general subspace weighting, and the weighting that provides minimum variance estimates is identified. The resulting optimal technique is termed the weighted subspace fitting (WSF) method. Numerical examples indicate that the asymptotic variance of the WSF estimates coincides with the Cramer-Rao bound. The performance improvement compared to the other techniques is found to be most prominent for highly correlated signals.
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| 25. |
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| 26. |
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| 27. |
- Fridén, Håkan, et al.
(författare)
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Multivariate process monitoring and forcasting by projection methods
- 1994
-
Ingår i: Proceedings of the Third IEEE Conference on Control Applications Glasgow, 24-26 aug 1994. - Piscataway : IEEE Control Systems Society. ; , s. 1345-1346
-
Konferensbidrag (refereegranskat)abstract
- Immense amounts of data are collected into today's modern process monitoring systems. There are, however, few methods that have the capability to grasp the essentials in these, usually heavily correlated, data. The multivariate statistical techniques, principal components (PC) modelling and modelling by projection to latent structures (PLS) are two methods that have a great potential for process monitoring and forecasting in these situations
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| 28. |
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| 29. |
- Carlemalm, Catharina, et al.
(författare)
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On the Problem of Detection and Discrimination of Double Talk and Change in the Echo Path
- 1995
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The problem of detection and discrimination of double talk and change in the echo path in a telephone channel is considered. The phenomenon echo path change requires fast adaptation of the channel model to be able to equalize the echo dynamics. On the other hand, the adaption rate should be reduced when double talk occurs. Thus, it is critical to quickly detect a change in the echo path while not confusing it with double talk, which gives a similar effect. The proposed likelihood based approach compares a global channel model with a local one over a sliding window, both estimated with the recursive least squares algorithm.
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| 30. |
- Gustafsson, Fredrik
(författare)
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Determining the Initial States in Forward-Backward Filtering
- 1994
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Forward-backward filtering is a common tool in off-line filtering for implementing noncausal filters. Filtering first forward and then backward or the other way around does not generally give the same result. Here, we propose a method to choose the initial state to obtain uniqueness and to remove transients at both ends.
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| 31. |
- Gustafsson, Fredrik, et al.
(författare)
-
On Time-Frequency Resolution of Signal Properties using Parametric Techniques
- 1995
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The problem to track time-varying properties of a signal is studied. The somewhat contradictory notion of “time-varying spectrum” and how to estimate the “current” spectrum in an on-line fashion is discussed. The traditional concepts and relations between time- and frequency resolution are crucial for this problem. An adaptive estimation algorithm is used to estimate the parameters of a time-varying autoregressive model of the signal. It is shown how this algorithm can be equipped with a feature such that the time-frequency resolution trade-off favors quick detection of changes at higher frequencies and has slower adaptation at lower frequencies. This should be an attractive feature and similar to, for example, what wavelet transform techniques achieve for the same problem.
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| 32. |
- Gustafsson, Fredrik, et al.
(författare)
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On Time-Frequency Resolution of Signal Properties using Parametric Techniques
- 1993
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The problem to track time-varying properties of a signal is studied. The somewhat contradictory notion of “time-varying spectrum” and how to estimate the “current” spectrum in an on-line fashion is discussed. The traditional concepts and relations between time- and frequency resolution are crucial for this problem. An adaptive estimation algorithm is used to estimate the parameters of a time-varying autoregressive model of the signal. It is shown how this algorithm can be equipped with a feature such that the time-frequency resolution trade-off favors quick detection of changes at higher frequencies and has slower adaptation at lower frequencies. This should be an attractive feature and similar to, for example, what wavelet transform techniques achieve for the same problem.
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| 33. |
- Gustafsson, Fredrik
(författare)
-
Segmentation of Signals Using Piecewise Constant Linear Regression Models
- 1994
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The signal segmentation approach described herein assumes that the signal can be accurately modelled by a linear regression with piece-wise constant parameters. A simultaneous estimate of the change times is considered. The maximum likelihood and maximum a posteriori probability estimates are derived after marginalization of the linear regression parameters and the measurement noise variance, which are considered as nuisance parameters. A well-known problem is that the complexity of segmentation increases exponentially in the number of data. Therefore, two inequalities are derived enabling the exact estimate to be computed with quadratic complexity. A linear in time complexity recursive approximation is proposed as well, based on these inequalities. The method is evaluated on a speech signal previously analyzed in literature, showing that a comparable result is obtained directly without the usual tuning effort. It is also detailed how it successfully has been applied in a car for online segmentation of the driven path for supporting guidance systems.
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| 34. |
- Pogromsky, Alexander, et al.
(författare)
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On Diffusion Driven Oscillations in Coupled Dynamical Systems
- 1998
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The paper deals with the problem of destabilization of diffusively coupled identical systems. It is shown that globally asymptotically stable systems being diffusively coupled, may exhibit oscillatory behavior. It is shown that if the diffusive medium consists of hyperbolically nonminimum phase systems and the diffusive factors exceed some threshold value, the origin of the overall system undergoes a Poincare-Andronov-Hopf bifurcation resulting in oscillatory behavior.
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| 35. |
- Renhorn, Ingmar, et al.
(författare)
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Coherent Laser Radar for Vibrometry : Robust Design and Adaptive Signal Processing
- 1995
-
Ingår i: Proceedings of the 1995 SPIE Conference on Applied Laser Radar Technology II. - Linköping : Linköping University. - 9780819418258 ; , s. 23-30
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A coherent laser radar system based on semiconductor laser technology has been designed and built. The compact design and the absence of adjustments makes the system mechanically robust and easy to use. The present system has an output power of 50 mW and a line width of 280 kHz (HWHM). The laser radar system has been used in vibrometry measurements. For vibrometry of moving objects, adaptive signal processing is required in order to obtain the vibration signature. Especially for unresolved objects, interference between different vibrating parts will complicate the analysis. Modelbased estimation techniques are used to obtain the parameters which determine the dynamics of the reflecting object.
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| 36. |
- Bengtsson, Lars, 1963
(författare)
-
Avancerad Elektrisk Mätteknik
- 1996
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Boken är avsedd för fortsättnigskurser i elektrisk mätteknik på högskolenivå. Den lämpar sig också väl som kompletteringslitteratur för kurser i signalbehandling. Innehållet är framför allt koncentrerat till analog och digital frekvensanalys, brusreducerande mätmetoder och AD/DA-omvandlingsmetoder. Ett kapitel tar upp signalbehandling och sambanden mellan analys i tid och rum. Fouriertransformen och faltningsintegralen gås igenom i detalj. Boken avslutas dels med ett kapitel om snabba förlopp i transmissionsledningar, dels med ett kapitel om GPIB-bussen. I appendix finns även en beskrivning av RS-232-kommunikation.
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| 37. |
- Berbyuk, Viktor, 1953
(författare)
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Dynamics and optimal control of biotechnical systems "Man-Prosthesis"
- 1997
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Ingår i: IUTAM Symposium on Interaction Between Dynamics and Control in Advanced Mechanical Systems, Ed. D. van Campen, Kluwer Academic Publishers, 1997. - Dordrecht : Springer Netherlands. ; , s. 35-42
-
Konferensbidrag (refereegranskat)abstract
- In the paper, a mathematical model is proposed for investigating the controlled motion of human locomotion system (HLS) with an above-knee prosthesis. To provide insight into the interaction between dynamics and control in biotechnical system Man-Prosthesis the energy optimal control problem of the HLS wearing a lower limb prosthesis has been considered. The algorithm is based on special conversion of the optimal control problem for a nonlinear dynamical system which models HLS into a standard nonlinear programming problem. A number of energy-optimal control problems of human locomotion with an artificial leg, and optimization problems for the constructive parameters of the prostheses under different boundary conditions and constraints have been solved. The numerical results obtained were compared with experimental data for normal human locomotion. The energy-optimal elastic and viscoelastic characteristics of the ankle and knee joints of the prostheses have been determined.
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| 38. |
- Berbyuk, Viktor, 1953
(författare)
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Multibody systems modeling and optimization problems of lower limb prostheses
- 1996
-
Ingår i: 1996 IUTAM Symposium on Optimization of Mechanical Systems. - Dordrecht : Springer Netherlands. ; , s. 25-32
-
Konferensbidrag (refereegranskat)abstract
- To study the effect of prosthesis design on the kinematic, dynamic, energetic and other characteristics of an amputee's locomotion and to improve and create new efficient lower limb prostheses it is expendient to use mathematical modeling of a human walk process and dynamic optimization techniques. In this paper a mathematical model is proposed for investigating the dynamics of a man's skeletal system (MSS) with a below-knee prosthesis. A MSS is simulated by a plane controlled dynamic system of rigid masses. The controlled motions of the system are described by Lagrange's equations of the second kind, and for the expressions for kineto-static balance of the prosthesis under the action of ankle and metatarsal moments and the forces of reactions are derived. An algorithm is construced for solving the problem of human gait dynamics with a below-knee prosthesis. The series of dynamics problems for multibody biothechnical system "Man-Prosthesis" and optimization of structural parameters of the artificial lower extremity of a man has been solved.
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| 39. |
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| 40. |
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| 41. |
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| 42. |
- Lagerberg, Adam, et al.
(författare)
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Gain Scheduling Design using Feedback Gain Bias Compensation
- 1995
-
Ingår i: The 2nd Russian-Swedish Control Conference, St.\ Petersburg, Russia. - : Control Engineering Laboratory, Chalmers University of Technology, Gothenburg, Sweden.
-
Rapport (övrigt vetenskapligt/konstnärligt)
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| 43. |
- Ljung, Lennart, 1946-, et al.
(författare)
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Adaptive System Performance in the Frequency Domain
- 1992
-
Ingår i: Adaptive systems in control and signal processing 1992. - Linköping : Linköping University. - 9780080425962 ; , s. 33-40
-
Konferensbidrag (refereegranskat)
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| 44. |
- Strömberg, Jan-Erik, et al.
(författare)
-
Complex Hybrid Systems I : a Study of Available Tools and Specification of Planned Work
- 1994
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this report is twofold. First, to provide a common framework and terminology for the participants of the Nutek supported COHSY project a multi-disciplinary academic-industrial cooperation on COmplex Hybrid SYstems. Second, to define more precisely the activities within the nest few years of the project. Therefore, the current report should be considered as a project definition rather than a statement about the constructive work currently in progress.
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| 45. |
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| 46. |
- Edström, Krister
(författare)
-
Mode Initialization when Simulating Switched Bond Graphs
- 1997
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- When simulating hybrid systems using switched bond graphs, the initialization of new modes is made by using a generalization of the principle of momentum conservation. Here it is shown how to use causality propagation to get an efficient initialization algorithm. By looking at causal paths, set of variables that have to be initialized simultaneously are found. Furthermore, it is shown how impulses due to structural changes in the system can be found with a correct initialization and with a correct treatment of modes with causal conflicts between sources.
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| 47. |
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| 48. |
- Fodor, George, 1954-, et al.
(författare)
-
Modeling the real-time recovery of complex control systems : A fuzzy approach
- 1997
-
Ingår i: 1997 IEEE International Conference on Systems, Man, and Cybernetics. - New York, USA : IEEE conference proceedings. - 0780340531 ; , s. 2163-2168
-
Konferensbidrag (refereegranskat)abstract
- This paper presents an approach to complex system recovery based on a fuzzy specification method. The method can be applied when controllers of different types and makes are connected in a common control architecture. The method allows a controller B to trigger a recovery operation on a controller A when B has the recovery specification of A. The approach has important potential applications in industry, e.g. as a possible complement to PLC standards such as IEC1131, and to the design of hybrid and complex control systems
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| 49. |
- Forssell, Urban, et al.
(författare)
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Efficiency of Prediction Error and Instrumental Variable Methods for Closed-loop Identification
- 1998
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Ingår i: Proceedings of the 37th IEEE Conference on Decision and Control. - Linköping : Linköping University Electronic Press. - 0780343948 ; , s. 1287-1288 vol.2
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We study the efficiency of a number of closed-loop identification methods. Results will be given for methods based on the prediction error approach as well as those based on the instrumental variable approach. Moreover, interesting insights in the properties of a recently suggested subspace method for closed-loop identification are obtained by exploring the links between this method and the instrumental variable method.
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| 50. |
- Forssell, Urban
(författare)
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Identification for Control : Unification of some Existing Schemes
- 1997
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper shows how the identification step in several identification for control schemes can be performed in a unified and simplified manner. We utilize a particularly simple indirect method for closed-loop identification and show how the fix noise model/prefilter should be chosen in order to match the identification and control criteria
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