Few-Shot Remote Sensing Scene Classification (FSRSSC) aims at recognizing novel categories with only a few labeled samples. Local representations can retain richer details than image-level feature vectors and adapt we...
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In this paper, a fault-tolerant-based online critic learning algorithm is developed to solve the optimal tracking control issue for nonaffine nonlinear systems with actuator ***, a novel augmented plant is constructed...
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In this paper, a fault-tolerant-based online critic learning algorithm is developed to solve the optimal tracking control issue for nonaffine nonlinear systems with actuator ***, a novel augmented plant is constructed by fusing the systemstate and the reference trajectory, which aims to transform the optimal fault-tolerant tracking control design with actuator faults into the optimal regulation problem of the conventional nonlinear error system. Subsequently, in order to ensure the normal execution of the online learning algorithm, a stability criterion condition is created to obtain an initial admissible tracking policy. Then, the constructed model neural network(NN) is pretrained to recognize the system dynamics and calculate trajectory control. The critic and action NNs are constructed to output the approximate cost function and approximate tracking control,respectively. The Hamilton-Jacobi-Bellman equation of the error system is solved online through the action-critic framework. In theoretical analysis, it is proved that all concerned signals are uniformly ultimately bounded according to the Lyapunov *** tracking control law can approach the optimal tracking control within a finite approximation error. Finally, two experimental examples are conducted to indicate the effectiveness and superiority of the developed fault-tolerant tracking control scheme.
In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of ...
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In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of feedback information, such as measurements and control signals, over digital networks, presenting novel challenges in estimation and control design. Our examination encompasses various topics, including the minimal information needed for effective feedback control, the design of quantizers, strategies for quantized control design and estimation,achieving consensus control with quantized data, and the pursuit of high-precision tracking using quantized measurements.
Stiffness adjustment is an important feature of human arm *** adaptive variable impedance control can adapt to the robotic stiffness,but may result in a large *** this paper,nonlinear impedance control is proposed for...
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Stiffness adjustment is an important feature of human arm *** adaptive variable impedance control can adapt to the robotic stiffness,but may result in a large *** this paper,nonlinear impedance control is proposed for collaborative robotic grinding,where nonlinear force feedback is designed to compensate for the nonlinear stiffness of the ***,the interaction system can be linearization to ensure the system ***,a target trajectory adaptation strategy is studied to ensure the force tracking ***,switching law between trajectory tracking and force tracking is proposed when the robot performs a complex grinding *** stability of the switch control as well as the trajectory adaptation law is *** are conducted in a robotic grinding test rig,where the robot is used to grind a turbine *** results show that the nonlinear impedance control can obtain stable grinding force,and have better grinding quality than the linear impedance control.
Background: In the manufacturing setup process of weapons, aviation, and aerospace, docking assembly is a key component in determining manufacturing efficiency and quality. The traditional docking method uses manual a...
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In this paper, molecular dynamics simulations are employed to investigate the temperature, stress distribution, microstructure and evolution of dislocations in singlecrystal Ni-based superalloys during femtosecond las...
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In this paper, molecular dynamics simulations are employed to investigate the temperature, stress distribution, microstructure and evolution of dislocations in singlecrystal Ni-based superalloys during femtosecond laser drilling of micro-holes. The results indicate that the temperature and stress variations in the model system increase with the increment of laser energy density. The pulse width has a relatively low effect on temperature and stress variations. At the same time, an increase in dislocations is primarily related to energy density and stress distribution. The number of dislocations increases with the energy density, with the 1/6<112> dislocation showing the highest increase ratio. The densest concentration of dislocations occurs at the hole walls. Dislocations and stacking faults gradually penetrate the precipitate phase under the influence of temperature and reach a stable state as the relaxation time increases. The above research findings provide important theoretical guidance for understanding the microstructure evolution and changes in the mechanical properties of single-crystal Ni-based superalloys during femtosecond laser processing of micro-holes.
This paper mainly addresses control problems of strict-feedback systems(SFSs)with increasing *** with the commonly-considered SFSs where the subsystems have the same dimension,we aim to handle more complex cases,i.e.,...
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This paper mainly addresses control problems of strict-feedback systems(SFSs)with increasing *** with the commonly-considered SFSs where the subsystems have the same dimension,we aim to handle more complex cases,i.e.,the subsystems in the considered SFSs are assumed to have increasing *** transforming the systems into highorder fully-actuated system(HOFAS)models,the stabilizing controllers can be directly *** first-order SFSs,secondorder and high-order SFSs are also considered.
Bio-inspired magnetic helical microrobots have great potential for biomedical and micromanipulation applications. Precise interaction with objects in liquid environments is an important prerequisite and challenge for ...
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Bio-inspired magnetic helical microrobots have great potential for biomedical and micromanipulation applications. Precise interaction with objects in liquid environments is an important prerequisite and challenge for helical microrobots to perform various tasks. In this study, an automatic control method is proposed to realize the axial docking of helical microrobots with arbitrarily placed cylindrical objects in liquid environments. The docking process is divided into ascent, approach, alignment, and insertion stages. First, a 3D docking path is planned according to the positions and orientations of the microrobot and the target object. Second, a steering-based 3D path-following controller guides the helical microrobot to rise away from the container bottom and approach the target along the path. Third, based on path design with gravity compensation and steering output limits, alignment of position and orientation can be accomplished simultaneously. Finally, the helical microrobot completes the docking under the rotating magnetic field along the target orientation. Experiments verified the automatic docking of the helical microrobot with static targets, including connecting with micro-shafts and inserting into micro-tubes. The object grasping of a reconfigurable helical microrobot aided by 3D automatic docking was also demonstrated. This method enables precise docking of helical microrobots with objects, which might be used for capture and sampling, in vivo navigation control, and functional assembly of microrobots.
The optimal control of nonlinear systems is crucial to improve system performance. However, the uncertainties of cost functions and systems dynamics make it difficult to solve the optimal control laws. To cope with th...
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The surface quality of a corrugated plate directly determines the heat transfer property of the thermal power mechanical *** detection methods are impractical for real-world production,being slow and *** contrast,the ...
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The surface quality of a corrugated plate directly determines the heat transfer property of the thermal power mechanical *** detection methods are impractical for real-world production,being slow and *** contrast,the point laser displacement sensor,employing the optical triangle method,emerges as a promising device for assessing parts with variable curvature and highly reflective *** its benefits,high-density sampling by an innate frequency introduces challenges such as data redundancy and a poor signal-to-noise ratio,potentially affecting the efficiency and precision of subsequent data *** address these challenges,adjustable frequency data sampling has been developed for this sensor,allowing adaptive sampling for corrugated plate *** process begins with surface digitization to extract discrete points,which are transformed into intersection curves using the B-spline fitting ***,dominant points are identified,considering multigeometric constraints for curvature and arch ***,the sampling signal is adjusted based on the distribution information of dominant *** results indicate that the proposed method effectively minimizes redundant sampling without compromising the accurate capture of essential geometric features.
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