Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the ...
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Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the continuous fault-tolerant control protocol via observer design is developed. In addition, it is strictly proved that the multi-agent system driven by the designed controllers can still achieve bipartite consensus tracking after faults occur.
A quantitative relationship between grain size and Young's modulus of metal composites has not been established by considering the coupling effect of the reinforcements on microstructural *** objective of this stu...
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A quantitative relationship between grain size and Young's modulus of metal composites has not been established by considering the coupling effect of the reinforcements on microstructural *** objective of this study is to investigate the mechanism of deformation coordination between the carbon nanotube and the composite microstructure using molecular dynamics *** the analysis of stress contributions from grain boundaries and grains,a grain size-dependent continuum model for the pure metal modulus is *** this basis,a predictive model for the modulus of metallic composites is developed by considering the coupling deformation between carbon nanotubes and the *** proposed model is capable of accurately capturing the relationship between grain size and the modulus of metal *** study provides a guideline for microstructure-dependent multiscale modeling.
The emergence of new display devices,such as organic light-emitting diodes,has brought about numerous advantages,including high material utilization,low cost,and high *** devices are manufactured using inkjet printing...
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The emergence of new display devices,such as organic light-emitting diodes,has brought about numerous advantages,including high material utilization,low cost,and high *** devices are manufactured using inkjet printing and possess the potential to become a keytechnology for display ***,a challenge in achieving this is the display effect that reveals uneven brightness and darkness,which can be avoided by controlling the volume of ink solution in a pixel to within 5%.Currently,the volume difference among the nozzles of commercial printheads does not meet the requirements for volume uniformity,thus challenging the printing ***,designing a suitable printing method that allows for the fusion of different volumes of ink droplets,ultimately reducing the error of the post fusion process,is *** this study,we propose a print display droplet fusion scheduling method comprising two main ***,we use a dichotomous trust domain algorithm to obtain a feasible range of printhead docking point spacings for different nozzle and pixel panel ***,we model the printing process as a droplet fusion scheduling model based on mixed integer programming,with the optimization objective of achieving intra pixel volume uniformity via ensuring the volume uniformity of ink droplets within all *** verified this method through numerical simulations and printing experiments using 394 pixels per inch(ppi)pixel panels and successfully reduced the volume uniformity error among pixels to within 5%.
Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm ...
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Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm is proposed for the urban rescue search or military search in outdoor *** to flexible control of small UAVs, it can be considered that all UAVs fly at the same altitude, that is, they perform search tasks on a two-dimensional plane. Based on the agents’ motion characteristics and environmental information, a mathematical model of CCPP problem is established. The minimum time for UAVs to complete the CCPP is the objective function, and complete coverage constraint, no-fly constraint, collision avoidance constraint, and communication constraint are considered. Four motion strategies and two communication strategies are designed. Then a distributed CCPP algorithm is designed based on hybrid strategies. Simulation results compared with patternbased genetic algorithm(PBGA) and random search method show that the proposed method has stronger real-time performance and better scalability and can complete the complete CCPP task more efficiently and stably.
Design and manufacturing play pivotal roles in hydraulic-driven robotic ***,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing *** paper int...
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Design and manufacturing play pivotal roles in hydraulic-driven robotic ***,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing *** paper introduces a novel approach known as light weight design and integrated manufacturing(LD&IM)for hydraulic wheel-legged *** LD&IM method leverages topology optimization and generative design techniques to achieve a substantial 45%weight reduction,enhancing the robot’s dynamic motion *** innovative design method not only streamlines the design process but also upholds the crucial attributes of light weight construction and high strength essential for hydraulic wheel-legged ***,the integrated manufacturing method,incorporating selective laser melting(SLM)and high-precision subtractive manufacturing(SM)processes,expedites the fabrication of high-quality *** the LD&IM approach,a hydraulic-driven single wheel-legged robot,denoted as WLR-IV,has been successfully *** robot boasts low mass and inertia,high strength,and a simplified component *** assess its dynamic jumping capabilities,the control loop integrates a linear quadratic regulator(LQR)and zero dynamic-based controller,while trajectory planning uses the spring-loaded inverted pendulum(SLIP)*** jumping results confirm the WLR-IV single-legged robot’s exceptional dynamic performance,validating both the effectiveness of the LD&IM method and the rationale behind the control strategy.
Strict requirement of a coherent spectrum in coherent diffractive imaging(CDI)architectures poses a significant obstacle to achieving efficient photon utilization across the full *** date,nearly all broadband computat...
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Strict requirement of a coherent spectrum in coherent diffractive imaging(CDI)architectures poses a significant obstacle to achieving efficient photon utilization across the full *** date,nearly all broadband computational imaging experiments have relied on accurate spectroscopic measurements,as broad spectra are incompatible with conventional CDI *** paper presents an advanced approach to broaden the scope of CDI to ultra-broadband illumination with unknown probe spectrum,effectively addresses the key challenges encountered by existing state-ofthe-art broadband diffractive imaging *** advancement eliminates the necessity for prior knowledge of probe spectrum and relaxes constraints on non-dispersive samples,resulting in a significant extension in spectral bandwidth,achieving a nearly fourfold improvement in bandlimit compared to the existing *** method not only monochromatizes a broadband diffraction pattern from unknown illumination spectrum,but also determines the compressive sampled profile of spectrum of the diffracted *** superiority is experimentally validated using both CDI and ptychography techniques on an ultra-broadband supercontinuum with relative bandwidth exceeding 40%,revealing a significantly enhanced coherence and improved reconstruction with high fidelity under ultra-broadband illumination.
Miniaturizing spectrometers for compact and cost-effective mobile platforms is a major challenge in current spectroscopy research,where conventional spectrometers are impractical due to their bulky *** miniaturized de...
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Miniaturizing spectrometers for compact and cost-effective mobile platforms is a major challenge in current spectroscopy research,where conventional spectrometers are impractical due to their bulky *** miniaturized designs primarily rely on precalibrated response functions of nanophotonic structures to encode spectral information captured in a snapshot by detector *** spectrum reconstruction is achieved through computational techniques,but this requires precise component design,high-precision fabrication,and *** propose an ultra-simplified computational spectrometer that employs a one-to-broadband diffraction decomposition strategy facilitated by a numerical regularized transform that depends only on the spectrum of the diffracted *** key feature of our design is the use of a simple,arbitrarily shaped pinhole as the partial disperser,eliminating the need for complex encoding designs and full spectrum *** spectrometer achieves a reconstructed spectral peak location accuracy of better than 1 nm over a 200 nm bandwidth and excellent resolution for peaks separated by 3 nm in a bimodal spectrum,all within a compact footprint of under half an ***,our approach also reveals a breakthrough in broadband coherent diffractive imaging without requiring any prior knowledge of the broadband illumination spectrum,assumptions of non-dispersive specimens,or correction for detector quantum efficiency.
We consider an optimal denial-of-service(DoS) attack scheduling problem of N independent linear time-invariant processes, where sensors have limited computational capability. Sensors transmit measurements to the remot...
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We consider an optimal denial-of-service(DoS) attack scheduling problem of N independent linear time-invariant processes, where sensors have limited computational capability. Sensors transmit measurements to the remote estimator via a communication channel that is exposed to DoS attackers. However,due to limited energy, an attacker can only attack a subset of sensors at each time step. To maximally degrade the estimation performance, a DoS attacker needs to determine which sensors to attack at each time step. In this context, a deep reinforcement learning(DRL) algorithm, which combines Q-learning with a deep neural network, is introduced to solve the Markov decision process(MDP). The DoS attack scheduling optimization problem is formulated as an MDP that is solved by the DRL algorithm. A numerical example is provided to illustrate the efficiency of the optimal DoS attack scheduling scheme using the DRL algorithm.
Dear Editor,This letter is concerned with stability analysis and stabilization design for sampled-data based load frequency control(LFC) systems via a data-driven method. By describing the dynamic behavior of LFC syst...
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Dear Editor,This letter is concerned with stability analysis and stabilization design for sampled-data based load frequency control(LFC) systems via a data-driven method. By describing the dynamic behavior of LFC systems based on a data-based representation, a stability criterion is derived to obtain the admissible maximum sampling interval(MSI) for a given controller and a design condition of the PI-type controller is further developed to meet the required MSI. Finally, the effectiveness of the proposed methods is verified by a case study.
Since the pioneering deployment of Canadarm in 1981,various on-orbit servicing (OOS) concepts have been flourishing and are continuously demonstrated by space agencies worldwide[1].This novel access to extend human cu...
Since the pioneering deployment of Canadarm in 1981,various on-orbit servicing (OOS) concepts have been flourishing and are continuously demonstrated by space agencies worldwide[1].This novel access to extend human curiosity in space is empowered by the remarkable OOS progress achieved by missions like the Robot technology Experiment (ROTEX),Engineering Test Satellite-Ⅶ(ETS-Ⅶ),
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