This paper investigates an interval analysis method for neural networks and applies it to fault detection for systems with unknown but bounded measurement noise. First, a novel interval analysis method is presented, w...
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This paper investigates an interval analysis method for neural networks and applies it to fault detection for systems with unknown but bounded measurement noise. First, a novel interval analysis method is presented, which can compute the bounds of the output of a feedforward neural network subject to a bounded input. By applying the proposed interval analysis method to a network trained with fault-free system data, adaptive thresholds for fault detection are computed. Finally, one can acquire fault detection results via a fault detection strategy. The proposed method can achieve tight bounds of the network output and employ simple operations, which leads to accurate fault detection results and a low computational burden.A numerical simulation and an experiment on an AC servo motor are given to illustrate the effectiveness and superiority of the proposed method.
This paper introduces a target tracking control approach for an underactuated Unmanned Surface Vehicle (USV) with 6 Degrees of Freedom (6-DoF), characterized by unknown dynamics and disturbances. Notably, the system i...
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This paper introduces a target tracking control approach for an underactuated Unmanned Surface Vehicle (USV) with 6 Degrees of Freedom (6-DoF), characterized by unknown dynamics and disturbances. Notably, the system inertia matrix of this 6-DoF USV is positive definite and non-diagonal, implying the presence of intricate coupling relationships within the input vector components. To address the challenges posed by underactuation, we present an adaptive control methodology utilizing a novel transverse function and backstepping procedure. Furthermore, we introduce a dynamic signal to compensate for external dynamic uncertainties and disturbances. Leveraging Lyapunov stability theory, we establish that the target tracking error converges to a small neighborhood near the origin, and all signals within the closed-loop system remain bounded. Lastly, we showcase the effectiveness of the proposed control methodology through simulation results involving a 6-DoF supply vehicle. IEEE
This paper considers the time difference of arrival(TDOA)and frequency difference of arrival(FDOA)estimation problem for joint localization using unmanned aerial vehicles(UAVs),involving range migration(RM)and Doppler...
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This paper considers the time difference of arrival(TDOA)and frequency difference of arrival(FDOA)estimation problem for joint localization using unmanned aerial vehicles(UAVs),involving range migration(RM)and Doppler ambiguity within observation interval.A robust estimation method based on interpolation and resampling is ***,the interpolation artificially increases the pulse repetition frequency(PRF).After that,the resampling eliminates the coupling between range frequency and slow ***,a coherent integration step based on inverse discrete Fourier transform(IDFT)is used to achieve parameter estimation and suppress the grating lobes caused by *** proposed method could be efficiently implemented by fast Fourier transform(FFT),inverse FFT(IFFT)and non-uniform FFT(NUFFT)without parameter searching *** experiments indicate that the proposed method has nearly optimal anti-noise performance but much lower computational complexity than the maximum likelihood estimator,which makes it more competitive in practical applications.
Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military ***,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstructi...
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Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military ***,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstruction due to the intractable constraints of existing ***,we conceptually propose and experimentally demonstrate a simple and feasible pathway of using a well-designed color liquid crystal grating to overcome the inevitable chromatic aberration and enlarge the holographic viewing angle,thus enabling large-viewing-angle and color holographic 3D *** use of color liquid crystal grating allows performing secondary diffraction modulation on red,green and blue reproduced images simultaneously and extending the viewing angle in the holographic 3D display *** principle,a chromatic aberration-free hologram generation mechanism in combination with the color liquid crystal grating is proposed to pave the way for on such a superior holographic 3D *** proposed system shows a color viewing angle of~50.12°,which is about 7 times that of the traditional system with a single spatial light *** work presents a paradigm for achieving desirable holographic 3D display,and is expected to provide a new way for the wide application of holographic display.
Vehicle platoon is one of the concrete manifestations of multi-vehicle cooperative control and intelligent transportation. However, the velocity perturbation in the driving process will bring about stability and safet...
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The demand for flexible shielding has been rapidly growing in recent *** materials using solid metals,carbon materials,or MXenes as shielding units usually have difficulty in combining high shielding and flexibility(s...
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The demand for flexible shielding has been rapidly growing in recent *** materials using solid metals,carbon materials,or MXenes as shielding units usually have difficulty in combining high shielding and flexibility(stretching and bending characteristics),and thus they gradually fail to meet the shielding needs of flexible ***,shielding materials with both flexibility and high conductivity are urgent to fill this ***-based room temperature liquid metal(LM)is an emerging functional material with a low melting point,low viscosity,low modulus,and easy ***,due to wettability and compatibility issues,it is difficult to apply bulk LMs directly in the field of electromagnetic shielding(EMS).The article reviews the fabrication methods,performance,and applications of LMs EMS materials from three perspectives:Macroscopic LMs,micro/nano-LMs,and LM-based *** gallium-based liquid EMS materials demonstrate the characteristics of high shielding performance with stretchability and a wide shielding *** this review,different types of gallium-based LM materials are described from macroscopic to microscopic,from liquid to semi-solid,from high density to low density,from room temperature to ultra-low temperature,and from monolayer structure to multilayer *** prospect of LM materials as amorphous high-performance EMS materials is demonstrated in various applications,such as mobile communication,astronomical observation,radar,and medical detection,showing tremendous potential in the EMS field.
A distributed fault-tolerant formation control law is designed in this paper for multi-agent systems under external disturbances and actuator faults including time-varying loss of effectiveness faults. The initial pos...
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An enhanced approach utilizing APF(artificial potential field) method is introduced in this paper. By adopting this approach, the challenge of local minima that may occur when dealing with local path planning for unma...
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作者:
Tuong Nguyen, V.Ta Bui, L.Envim Group
National Key Laboratory of Digital Control and System Engineering (DCSELab) National University Ho Chi Minh City (VNU-HCM) Ho Chi Minh City Vietnam Department of Geography
Portland State University Portland USA
In numerous developing nations, untreated or poorly treated wastewater poses a major threat to ecosystems, significantly harming local biodiversity. Ensuring sustainable water resources that protect human health and e...
In numerous developing nations, untreated or poorly treated wastewater poses a major threat to ecosystems, significantly harming local biodiversity. Ensuring sustainable water resources that protect human health and ecosystems requires considering diverse factors and indicators simultaneously. Evaluating water quality (WQ) and river water environmental capacity (RWEC) is essential for determining the required level of wastewater treatment and the river channel’s receiving capacity. This study aims to investigate the impact of wastewater treatment on WQ and RWEC within a rapidly urbanizing watershed that suffers from inadequate planning. Eco-hydrodynamic models are applied to assess WQ and RWEC under the influence of pollution sources. Three characteristic pollutants in the area are considered: BOD, Nitrate, and Phosphate. Data on the sources of pollution, including the flow and quality of untreated and poorly treated wastewater, are collected. Additionally, meteorological and hydrological factors, as well as water quality monitoring data in the study area, are used. Three scenarios are considered based on the actual discharge in the area: the current scenario, the poorly treated scenario, and the scenario with treatment at permissible levels by enterprises. The results show that currently, the Nghèn River, the subject of the study, is negatively affected by pollution sources, with 54.17% of the reach not meeting BOD standard and 25% of the reach not meeting Phosphate standard. Meanwhile, the river’s waste assimilation capacity is significantly impacted by current pollution sources. Specifically, RWEC at 75% of the reach can no longer assimilate BOD, 50% for Nitrate, and 75% for Phosphate. These figures increase under the poorly treated scenario. To maintain environmental health and biodiversity, strict sanctions must be imposed on enterprises that do not comply with wastewater treatment regulations.
In the field of railway transportation, with the continuous improvement of train running speed and the continuous increase of operating mileage, it becomes particularly important to ensure the safety and integrity of ...
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