A new approach to technical condition monitoring of power units of aircraft and ship engines is suggested. It enables with the help of additional processing of two rotational velocity sensor outputs to get the informa...
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A new approach to technical condition monitoring of power units of aircraft and ship engines is suggested. It enables with the help of additional processing of two rotational velocity sensor outputs to get the information about variations of controlled process base parameters. The mathematical model of a transmission of a turboprop aircraft engine is deduced. Synthesis of adaptive algorithm of elastic shaft torsion angle estimation is developed. The task of turbine?s torque identification with the aim engine control improving and (or) for control of fatigue deterioration degree of the shaft?s material is considered. The possibility of the torsion angle adaptive estimation using for look-ahead cut-out of the engine in the case of a dangerous situation leading to destruction of the transportation is considered.
This work proposes an analysis of the pitch dynamics of a heavy-duty vehicle, namely an agricultural tractor. Considering maneuvers performed on a flat-asphalt surface, the analysis is performed through an image proce...
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This work proposes an analysis of the pitch dynamics of a heavy-duty vehicle, namely an agricultural tractor. Considering maneuvers performed on a flat-asphalt surface, the analysis is performed through an image processing approach. The analysis focuses on the cabin displacement and on the vehicle body displacement. Moreover, the tires compression and the vehicle longitudinal slip are evaluated. The analysis shows how the cabin and the body displacements change in function of the vehicle longitudinal acceleration and how, due to the tires compression, the cabin and the body can oscillate, at the end of a braking maneuver. The results are used to evaluate the feasibility of a road gradient estimator based on the inertial measurement of a mono axial accelerometer installed in the cabin. In particular, the cabin displacement needs to be considered and an additional sensor which measures the cabin speed is required to avoid a drop of performance.
This paper presents a new robust algorithm for the identification of linear time-invariant systems in the frequency domain. The method is computationally very efficient, and accurately synthesises transfer functions w...
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This paper presents a new robust algorithm for the identification of linear time-invariant systems in the frequency domain. The method is computationally very efficient, and accurately synthesises transfer functions which require a large amount of poles. Some numerical difficulties are avoided by combining the use of a Sanathanan-Koerner iteration and orthonormal rational functions.
In this paper, we introduce a new blind equalization algorithm based on the matrix decomposition of 4th-order statistics of received samples. The algorithm is easy to implement and resistant to the errors in computati...
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In this paper, we introduce a new blind equalization algorithm based on the matrix decomposition of 4th-order statistics of received samples. The algorithm is easy to implement and resistant to the errors in computation and modeling. Simulation results show that under a mild condition on the channel, it works well with a short symbol sequence even if the channel time-span is not accurately estimated.
This paper describes an uncalibrated visual-force control system which does not require any kinematic calibration to develop the task. An important aspect of these kinds of control systems is the necessity to maintain...
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This paper describes an uncalibrated visual-force control system which does not require any kinematic calibration to develop the task. An important aspect of these kinds of control systems is the necessity to maintain the coherence between the control actions obtained from each sensorial system. To do so, the paper proposes to modify the image trajectory from the information obtained from the force sensor by using the concept of force-image interaction matrix. This matrix relates changes in the image space with changes in the interaction forces. In order to estimate the value of this matrix this paper suggests the use of a Gauss-Newton method.
This paper presents an obstacle detection system for snow groomers. The system is based on a 2D solid-states LiDAR sensor mounted on the top of the cabin. The measurements describe the surrounding environment through ...
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This paper presents an obstacle detection system for snow groomers. The system is based on a 2D solid-states LiDAR sensor mounted on the top of the cabin. The measurements describe the surrounding environment through an Occupancy Grid framework, which is extended for this particular case study. The proposed approach set the occupancy probability of the surrounding environment based on the expected height of the obstacle. The method is extensively analyzed through experimental test on a snow groomer.
In this paper, a visual servoing for the tracking of objects in a plane using a fixed camera system is shown. The method proposed of tracking makes use of a variable number of trackers determined automatically. The in...
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In this paper, a visual servoing for the tracking of objects in a plane using a fixed camera system is shown. The method proposed of tracking makes use of a variable number of trackers determined automatically. The integration of the predictions of each of them affords a flexible and robust system of tracking. The studies of efficiency carried out reflect that the delays produced are suitable for use in visual servoing. The proposed system can be generalized to tracking three-dimensional objects with movable cameras.
An algorithm for estimating time positions and amplitudes of a periodic pulse sequence from a small number of samples was proposed. The number of these samples was determined only by the number of pulses. The performa...
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An algorithm for estimating time positions and amplitudes of a periodic pulse sequence from a small number of samples was proposed. The number of these samples was determined only by the number of pulses. The performance of this algorithm was considered on the assumption that the spectrum of the original signal is limited with an ideal low-pass filter or the Nyquist filter, and conditions for the conversion from one filter to the other were determined. The efficiency of the proposed algorithm was investigated through analyzing in which way the dispersion of estimates of time positions and amplitudes depends on the signal-to-noise ratio and on the number of pulses in the sequence. It was shown that, from this point of view, the efficiency of the algorithm decreases with increasing number of sequence pulses. Besides, the efficiency of the proposed algorithm decreases with decreasing signal-to-noise ratio. It was found that, unlike the classical maximum likelihood algorithm, the proposed algorithm does not require a search for the maximum of a multivariable function, meanwhile characteristics of the estimates are practically the same for both these methods. Also, it was shown that the estimation accuracy of the proposed algorithm can be increased by an insignificant increase in the number of signal samples. The results obtained may be used in the practical design of laser communication systems, in which the multipulse pulse-position modulation is used for message transmission.
Speech enhancement has been an intensive research for several decades to enhance the noisy speech that is corrupted by additive noise, multiplicative noise or convolutional noise. Even after decades of research it is ...
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Speech enhancement has been an intensive research for several decades to enhance the noisy speech that is corrupted by additive noise, multiplicative noise or convolutional noise. Even after decades of research it is still the most challenging problem, because most papers rely on estimating the noise during the nonspeech activity assuming that the background noise is uncorrelated (statistically independent of speech signal), nonstationary and slowly varying, so that the noise characteristics estimated in the absence of speech can be used subsequently in the presence of speech, whereas in a real time environment such assumptions do not hold for all the time. In this paper, we discuss the historical development of approaches that starts from the year 1970 to, the recent, 2013 for enhancing the noisy speech corrupted by additive background noise. Seeing the history, there are algorithms that enhance the noisy speech very well as long as a specific application is concerned such as the In-car noisy environments. It has to be observed that a speech enhancement algorithm performs well with a good estimation of the noise Power Spectral Density (PSD) from the noisy speech. Our idea pops up based on this observation, for online speech enhancement (i.e. in a real time environment) such as mobile phone applications, instead of estimating the noise from the noisy speech alone, the system should be able to monitor an environment continuously and classify it. Based on the current environment of the user, the system should adapt the algorithm (i.e. enhancement or estimation algorithm) for the current environment to enhance the noisy speech.
This report is devoted to an identification task for a linear time-lag model. There are a lot of them in economic dynamical problems. A coefficients and delay value calculating algorithm is offered.
This report is devoted to an identification task for a linear time-lag model. There are a lot of them in economic dynamical problems. A coefficients and delay value calculating algorithm is offered.
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