The popularity of quadrotor Unmanned Aerial Vehicles(UAVs)stems from their simple propulsion systems and structural ***,their complex and nonlinear dynamic behavior presents a significant challenge for control,necessi...
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The popularity of quadrotor Unmanned Aerial Vehicles(UAVs)stems from their simple propulsion systems and structural ***,their complex and nonlinear dynamic behavior presents a significant challenge for control,necessitating sophisticated algorithms to ensure stability and accuracy in *** strategies have been explored by researchers and control engineers,with learning-based methods like reinforcement learning,deep learning,and neural networks showing promise in enhancing the robustness and adaptability of quadrotor control *** paper investigates a Reinforcement Learning(RL)approach for both high and low-level quadrotor control systems,focusing on attitude stabilization and position tracking tasks.A novel reward function and actor-critic network structures are designed to stimulate high-order observable states,improving the agent’s understanding of the quadrotor’s dynamics and environmental *** address the challenge of RL hyper-parameter tuning,a new framework is introduced that combines Simulated Annealing(SA)with a reinforcement learning algorithm,specifically Simulated Annealing-Twin Delayed Deep Deterministic Policy Gradient(SA-TD3).This approach is evaluated for path-following and stabilization tasks through comparative assessments with two commonly used control methods:Backstepping and Sliding Mode Control(SMC).While the implementation of the well-trained agents exhibited unexpected behavior during real-world testing,a reduced neural network used for altitude control was successfully implemented on a Parrot Mambo mini *** results showcase the potential of the proposed SA-TD3 framework for real-world applications,demonstrating improved stability and precision across various test scenarios and highlighting its feasibility for practical deployment.
Covalent organic frameworks(COFs)are an emerging class for solid-state electrolytes due to their ordered and customizable ion transport *** high ionic conductivity(σ_(Li+))and Li^(+) transference number(t_(Li+))are a...
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Covalent organic frameworks(COFs)are an emerging class for solid-state electrolytes due to their ordered and customizable ion transport *** high ionic conductivity(σ_(Li+))and Li^(+) transference number(t_(Li+))are achieved;the high-arealcapacity solid-state lithium metal battery(LMB)still encountered challenges;which is mainly determined by homogeneous Li^(+) flux through channels and ***;we design a COF coupling anionic skeletons with branched ion-conductive chains(COF-S)as tailored fast ion-transport channels to achieve high-areal-capacity solid-state *** the dispersed COF-S-based electrolyte is further obtained by incorporating ethoxylated trimethylolpropane triacrylate(ETPTA)and Li FSI(ETPTA-COF-S)via in situ light *** this way;the abundant SO_(3)-groups promote Li+adsorption and facilitate axial transport via 1D channels;thus enabling highσLi+of 1.29 m S cm^(-1)and tLi+of *** branched chains can tailor ion channels to suppress largesize anions transport;disperse and uniform Li+flux;thus leading to high average Coulombic efficiency(CE)up to 98.43%for 100 cycles(~800 h)at 0.5 m A cm^(-2)under the high areal capacity of 2 mAh cm^(-2).When paired with 2 m Ah cm^(-2)LiFePO_(4)(LFP)cathode and thin Li anode of 20μm;Li||ETPTA-COF-S||LFP exhibits superior cyclic stability for 80 cycles.
A compact dual-band dual-circularly polarized antenna is proposed in this paper. The designed antenna adopts two radiation patches which are placed on two layers substrate respectively to achieve circularly polarized ...
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The traditional double reciprocating ultraclean bellows pump has a significant flow pulsation due to the minimum output flow, when one side of the bellows discharge ends and the other side begins to discharge. To redu...
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A high-temperature resistant ceramic-monoblock dielectric rod antenna operating at Ku-band is designed with thermal protection shield and thermal insulation material. Part of the ceramic-monoblock structure is plated ...
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Satellite-ground communication network will be an important network architecture in the coming six generation (6G). In this letter, we formulate a reconfigurable intelligent surface (RIS) assisted non-orthogonal multi...
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The accuracy of historical situation values is required for traditional network security situation prediction(NSSP).There are discrepancies in the correlation and weighting of the various network security *** solve th...
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The accuracy of historical situation values is required for traditional network security situation prediction(NSSP).There are discrepancies in the correlation and weighting of the various network security *** solve these problems,a combined prediction model based on the temporal convolution attention network(TCAN)and bi-directional gate recurrent unit(BiGRU)network is proposed,which is optimized by singular spectrum analysis(SSA)and improved quantum particle swarmoptimization algorithm(IQPSO).This model first decomposes and reconstructs network security situation data into a series of subsequences by SSA to remove the noise from the ***,a prediction model of TCAN-BiGRU is established respectively for each *** uses the TCN to extract features from the network security situation data and the improved channel attention mechanism(CAM)to extract important feature information from *** learns the before-after status of situation data to extract more feature information from sequences for ***,IQPSO is proposed to optimize the hyperparameters of ***,the prediction results of the subsequence are superimposed to obtain the final predicted *** the one hand,IQPSO compares with other optimization algorithms in the experiment,whose performance can find the optimum value of the benchmark function many times,showing that IQPSO performs *** the other hand,the established prediction model compares with the traditional prediction methods through the simulation experiment,whose coefficient of determination is up to 0.999 on both sets,indicating that the combined prediction model established has higher prediction accuracy.
Simultaneous localization and mapping (SLAM) systems frequently employ LiDAR and cameras as essential sensing components. However, these sensors are proved to be unreliable in environments with poor visibility or refl...
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Intraoperative Cone-Beam Computed Tomography (CBCT) facilitates intraoperative navigation for Minimally Invasive Spine Surgery (MISS). However, high-attenuation metal implants used in MISS often cause metal artifacts ...
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Automatic pavement crack detection is a critical task for maintaining the pavement stability and driving *** task is challenging because the shadows on the pavement may have similar intensity with the crack,which inte...
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Automatic pavement crack detection is a critical task for maintaining the pavement stability and driving *** task is challenging because the shadows on the pavement may have similar intensity with the crack,which interfere with the crack detection *** to the present,there still lacks efficient algorithm models and training datasets to deal with the interference brought by the *** fill in the gap,we made several contributions as ***,we proposed a new pavement shadow and crack dataset,which contains a variety of shadow and pavement pixel size *** also covers all common cracks(linear cracks and network cracks),placing higher demands on crack detection ***,we designed a two-step shadow-removal-oriented crack detection approach:SROCD,which improves the performance of the algorithm by first removing the shadow and then detecting *** addition to shadows,the method can cope with other noise ***,we explored the mechanism of how shadows affect crack *** on this mechanism,we propose a data augmentation method based on the difference in brightness values,which can adapt to brightness changes caused by seasonal and weather ***,we introduced a residual feature augmentation algorithm to detect small cracks that can predict sudden disasters,and the algorithm improves the performance of the model *** compare our method with the state-of-the-art methods on existing pavement crack datasets and the shadow-crack dataset,and the experimental results demonstrate the superiority of our method.
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