Ferroelectric ceramics display a remarkable photostriction effect,which could facilitate the prevention of electromagnetic interference and promote the integration and miniaturization of actuator systems,indicating po...
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Ferroelectric ceramics display a remarkable photostriction effect,which could facilitate the prevention of electromagnetic interference and promote the integration and miniaturization of actuator systems,indicating potential applications in glim-mer *** this work,highly transparent La-doped 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3(0.9PMN-0.1PT)ceramicswere synthesized using a solid-state reaction method in an oxyge-nated *** and SEM were used to analyze the phase structure of the dense samples,which displayed a pure perovskite structure,with no trace of a pyrochlore *** La doping,the phase transitiontemperature shows a decreasing trend,and its dielectric constant could reach up to 20,*** P-E loop of the samples was gradually refined into a straight line with an increase in the doping *** La doping,the transparency of the 0.9PMN-0.1PT cera-mics was significantly enhanced and reached up to 61%at the near-infrared ***,the photogenerated voltage and deformation of the La-doped 0.9PMN-0.1PT ceramics were investigated under ultraviolet light of various *** 20 s of irradiation at an intensity of 800 mW/cm²,the max-imum voltage and deformation,with values of 40 V and 250 nm,respectively,were both found in the 1%La-doped 0.9PMN-0.1PT ceramics.
In this paper, the cooperative output regulation(COR) problem of a class of unknown heterogeneous multi-agent systems(MASs) with directed graphs is studied via a model-free reinforcement learning(RL) based fully distr...
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In this paper, the cooperative output regulation(COR) problem of a class of unknown heterogeneous multi-agent systems(MASs) with directed graphs is studied via a model-free reinforcement learning(RL) based fully distributed eventtriggered control(ETC) strategy. First, we consider the scenario that the exosystem is accessible globally to all agents, an internal model-based augmented algebraic Riccati equation(AARE) is constructed, and its solution is learned by the proposed model-free RL algorithm via online input-output data. Further, for the scenario that the exosystem is accessible only to its adjacent followers, the distributed observers are designed for each agent to get the state of the exosystem, and an internal modelbased fully distributed adaptive ETC protocol is then synthesized to construct the corresponding AARE, and the feedback gain matrix is learned in a model-free fashion. The model-free RL-based control protocol proposed in this paper can not only remove the prior knowledge of agents' dynamics, but also release the dependence on global information by the adaptive event-triggered mechanism(ETM) and the new graph-based Lyapunov function. Finally, simulation results are illustrated to show the feasibility and effectiveness of the proposed control scheme.
In recent years, robot teleoperation systems have been widely used in assembly tasks due to their ability to combine human control with robotic execution, addressing limitations in precision, perception, and intellige...
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In recent years, robot teleoperation systems have been widely used in assembly tasks due to their ability to combine human control with robotic execution, addressing limitations in precision, perception, and intelligence faced by fully automated robots. However, robot teleoperation for assembly tasks still encounters several challenges. In complex and unstructured environments, telerobots must regulate the posture of their manipulators to avoid obstacles and singularities, ensuring the safety of human operators [1].
Learning from demonstration(LfD) allows for the effective transfer of human manipulation skills to a robot by building a model that represents these skills based on a limited number of demonstrated ***,a skilllearning...
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Learning from demonstration(LfD) allows for the effective transfer of human manipulation skills to a robot by building a model that represents these skills based on a limited number of demonstrated ***,a skilllearning model that can comprehensively satisfy multiple requirements,such as computational complexity,modeling accuracy,trajectory smoothness,and robustness,is still ***,this work aims to provide such a model by employing fuzzy ***,we introduce an LfD model named Takagi-Sugeno-Kang fuzzy system-based movement primitives(TSKFMPs),which exploits the advantages of the fuzzy theory for effective robotic imitation learning of human *** work formulates the TSK fuzzy system and gradient descent(GD) as imitation learning models,leveraging recent advancements in GD-based optimization for fuzzy *** study takes a two-step strategy.(ⅰ) The input-output relationships of the model are established using TSK fuzzy systems based on demonstration *** this way,the skill is encoded by the model parameter in the latent space.(ⅱ) GD is used to optimize the model parameter to increase the modeling accuracy and trajectory *** further explain how learned trajectories are adapted to new task scenarios through local *** conduct multiple tests using an open dataset to validate our method,and the results demonstrate performance comparable with those of other ***,we implement it in a real-world case study.
Facial Expression Recognition (FER) aims to cate-gorize emotional expressions depicted on a human face, and isa challenging task under unconstrained conditions, such as faceocclusions and pose variations. Recent metho...
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The development of microengineered hydrogels has opened up unlimited possibilities for designing complex structures at the microscale. In this study, we constructed an origami-inspired tubular structure with controlle...
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The development of microengineered hydrogels has opened up unlimited possibilities for designing complex structures at the microscale. In this study, we constructed an origami-inspired tubular structure with controlled mechanical buckling based on optically induced electrokinetics(OEK). By inducing a stress gradient in the thickness, a tubular structure can be formed from a poly(ethylene glycol) diacrylate(PEGDA) hydrogel film of various shapes that have been custom fabricated. To achieve an ideal three-dimensional(3D) structure, the amplitude of the tubular structure can be controlled by adjusting the aspect ratios or polymerization time. Furthermore, the tubular structure can be manipulated for the collection and transportation of *** summary, we provide an effective method for designing 3D structures at the micro-nano scale. This forming method holds great potential for achieving various functions in tissue engineering, drug packaging, and transportation in the future.
Aromatic hydrocarbons generally refer to compounds containing benzene *** types of isomers can be formed by replacing hydrogen atoms on the benzene *** this paper,an aromatic-hydrocarbon-inspired modular robot(AHIMR)i...
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Aromatic hydrocarbons generally refer to compounds containing benzene *** types of isomers can be formed by replacing hydrogen atoms on the benzene *** this paper,an aromatic-hydrocarbon-inspired modular robot(AHIMR)is *** robot can be reassembled into different configurations suitable for various task requirements.A vision-based docking system is designed for the *** system primarily consists of two stages:a remote guidance stage and a precise docking *** the remote guidance stage,an object module is identified using an illumination adaptive target recognition algorithm,and then the active module moves to the docking area through communication with *** the precise docking stage,the active module calculates the relative pose with the object module using a perspective-n-point method and dynamically adjusts its posture to *** this process,a Kalman filter is used to reduce target occlusion and jitter *** addition,the docking system feasibility is verified via several simulation *** module docking accuracy is controlled within 0.01 m,which meets the reconfiguration task requirements of the *** the AHIMR submodule docking experiment,the active module accurately moves to the expected position with a docking success rate of 95%.
Accurate contact force estimation is crucial for interactions between the robot arm and its environment. Presently, contact force estimation based on current information often suffers from biases caused by unmodeled e...
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In recent years,designing a soft robot that can jump continuously and quickly explore in a narrow space has been a hot research *** the continuous efforts of researchers,many types of actuators have been developed and...
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In recent years,designing a soft robot that can jump continuously and quickly explore in a narrow space has been a hot research *** the continuous efforts of researchers,many types of actuators have been developed and successfully employed to actuate the rapid locomotion of soft *** these mechanisms have enabled soft robots with excellent movement capabilities,they largely rely on external energy supply cables,which greatly limits their ***,it is still a big challenge to realize the unconstrained movement of the soft robot and the flexible adjustment of the movement direction in a narrow ***,a wireless magnetically controlled soft jumping robot with single-leg is proposed,which can achieve continuous and rapid jumping ***'s more interesting is that by changing the frequency and waveform of the control signal,this soft robot can easily switch between forward and backward *** motion direction switching function enables the magnetically controlled soft robot to return to the initial position without adjusting the direction when it completes the operation in a narrow pipe or takes the wrong path,which greatly improves the motion efficiency of the soft jumping robot and broadens its application field.
Researching the cooperative operation and functional expansion of multiple minirobot assemblies has the potential to bring about significant advancements in the practical applications of *** this study,we present a no...
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Researching the cooperative operation and functional expansion of multiple minirobot assemblies has the potential to bring about significant advancements in the practical applications of *** this study,we present a novel assembly sys-tem comprised of arc-shaped NdFeB magnetic *** minirobots can be individually utilized as assembly units,allowing for function expansion and comprehensive capability *** fabricate four Semicircular Arc Magnetic Minirobots(SAMM)arranged in different configurations and analyze their force and motion ***,by using this unit as a base,various expansion structures such as latches,petals,and rings can be assembled through reason-able *** define the comprehensive reinforcement interval by comparatively analyzing changes in the unit's motion characteristics and operational *** motion manipulation is employed to verify the rationality of the basic unit structure and the feasibility of the assembly *** proposed self-assembly scheme for magnetic minirobots exhibits great potential and may be used as a paradigm for future research on expanding the functionality of minirobots.
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