In this paper, we consider the problem of the accurate estimation of the depth in the specific context of 2D visual servoing. To this aim, we have developed a predictor/estimator pair. This depth will then be used to ...
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In this paper, we consider the problem of the accurate estimation of the depth in the specific context of 2D visual servoing. To this aim, we have developed a predictor/estimator pair. This depth will then be used to solve simultaneously three problems, namely the determination of the interaction matrix, the estimation of the visual features (when the image is temporarily unavailable) and the automatic computation of their reference values. Simulation results validate our work.
Two autopilots for track-keeping of the ship along the defined trajectory are described in the article: a linear quadratic output feedback controller and a cascaded robust controller. Both are using the rudder as the ...
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Two autopilots for track-keeping of the ship along the defined trajectory are described in the article: a linear quadratic output feedback controller and a cascaded robust controller. Both are using the rudder as the only control-actuator. The paper presents mathematical foundations of the problem, filtering techniques, and results of the simulations performed on a material ship model on the Silm Lake.
This paper presents a model based on the rigid water column (RWC) theory to describe the flow and the decay of chlorine in water distribution networks (WDNs), which can be used for developing tools to diagnose leaks a...
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This paper presents a model based on the rigid water column (RWC) theory to describe the flow and the decay of chlorine in water distribution networks (WDNs), which can be used for developing tools to diagnose leaks and estimate chlorine concentrations. The model includes the continuity equation for each node of the network such that i) the relation of the flow rates entering and leaving the nodes is explicit, and ii) the computation of pressures and flow rates can be simultaneously done. The chlorine decay in each node and in each pipeline section of the WDN is predicted from the computed flow rates by using the third order accurate Warming-Kutler-Lomax (WKL) method. At the end of this paper, it is shown that the chlorine decay rate is well predicted by using the WKL method according to a comparison with simulations results obtained by using the EPANET-MSX software. Furthermore, it is shown that several single leak-diagnosis scenarios can be successfully solved by using an improved sensitivity matrix method together with the proposed model.
In the Netherlands, an increasingly used traffic management measure is to prohibit trucks to overtake during peak hours. Real-life assessment of this measure shows mixed results, especially from the viewpoint of a mor...
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In the Netherlands, an increasingly used traffic management measure is to prohibit trucks to overtake during peak hours. Real-life assessment of this measure shows mixed results, especially from the viewpoint of a more efficient roadway use. The aim of this paper is to explain these results. One aspect of the analysis is considering differences in car-following behaviour between mixed-class vehicle pairs. It appears that possible increases in roadway capacity due to overtaking prohibitions for trucks are to a large extent determined by the traffic conditions and traffic flow composition. Secondly, by application of a recently developed macroscopic flow model for multiclass multilane traffic operations, the homogenising effects resulting from trucks on the left roadway lane are discussed.
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.
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 addresses the complex issues involved extending prediction intervals for inspection and maintenance of electrical protection equipment on manufacturing lines. Illustrations are based on representative data.
This paper addresses the complex issues involved extending prediction intervals for inspection and maintenance of electrical protection equipment on manufacturing lines. Illustrations are based on representative data.
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.
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