Predictive modeling of industrial rotating equipment is difficult due to a number of implementation challenges. Existing approaches are not well-equipped to adapt to the range of degradation trends that industrial equ...
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Colonoscopy is a widely used method for diagnosing bowel cancers, requiring coordinated efforts from medical professionals due to its invasive nature. In contrast, miniature capsule robots, measuring just a few centim...
Pesticide use in urban areas has human health and environmental impacts. The objective of this study was to assess the inhalation exposure of domestic dogs and their owners to pesticides. Dogs were studied due to thei...
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This paper presents the usages of conventional interpolation functions for interpolation-based parametric component mode synthesis (IB-PCMS) method within limited parameter domains. One of the representatives...
This paper presents the usages of conventional interpolation functions for interpolation-based parametric component mode synthesis (IB-PCMS) method within limited parameter domains. One of the representatives of reduced-order models (ROM) is the one using the offline-online strategy, which constructs multiple ROMs at given sampling points in the offline stage and manipulates them to derive a ROM at the new query point in the online stage efficiently via, for example, using the interpolation of the constructed ROMs. For such a process in the online stage, manifold interpolations, congruence transformations, and the mode exclusion steps are required to guarantee the accuracy and the robustness of the ROM, which complexifies computational procedures in the offline stage. For the cases where the design parameters do not change dramatically due to the limited domain of interest, and as a result, if the ROM does not experience any mode veering phenomena, simple interpolations can guarantee accurate solutions. The validities of using conventional interpolations are investigated for a numerical example providing the assessments of the accuracy for representative interpolation functions.
Deep reinforcement learning, when combined with demonstrations, can effectively formulate policies for manipulators. However, the practical collection of ample high-quality demonstrations is time-consuming, and demons...
Deep reinforcement learning, when combined with demonstrations, can effectively formulate policies for manipulators. However, the practical collection of ample high-quality demonstrations is time-consuming, and demonstrations generated by humans may not perfectly correspond with the operational demands of robots. These challenges are intensified by issues such as non-Markovian processes and excessive reliance on demonstrations. Our study indicates that in manipulation tasks, reinforcement learning (RL) agents are sensitive to the quality of demonstrations and struggle to adapt to those derived from humans. As a result, leveraging low-quality or scarce demonstrations to assist reinforcement learning in developing superior policies presents a significant challenge. In some cases, dependence on limited demonstrations may paradoxically impair performance. To address these challenges, we propose a novel algorithm, TD3fG (TD3 learning from a generator). This algorithm facilitates a seamless transition from learning from experts to learning from experience, enabling agents to assimilate prior knowledge while mitigating the negative impacts of the demonstrations. Our algorithm demonstrates notable improvement in the Adroit manipulator and MuJoCo tasks, even with limited demonstrations of mixed failure trajectory.
The worldwide need for sustainable energy solutions has continued to attract the attention of researchers. One vital means for such provision is the harvesting of energy using various methods. This study therefore rev...
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Electrohydrodynamic jet (e-jet) printing is a promising additive manufacturing technique that has demonstrated high-resolution fabrication capabilities. Various jetting regimes as a function of the input voltage signa...
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Anguilliform-swimming soft fluidic robots hold great promise for a range of underwater applications. However, because they leverage the complex dynamics of soft bodies interacting with fluids, it is challenging to use...
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ISBN:
(数字)9798331520205
ISBN:
(纸本)9798331520212
Anguilliform-swimming soft fluidic robots hold great promise for a range of underwater applications. However, because they leverage the complex dynamics of soft bodies interacting with fluids, it is challenging to use intuition to determine design parameters. Multidisciplinary design optimization offers a promising solution to this challenge by providing an automated and systematic method for leveraging computational models to find optimal design parameters. This study investigates a method for multidisciplinary control co-design optimization of anguilliform-swimming soft robots, using physics-based models to optimize shape and control parameters. The modeling framework includes a geometry-centric approach for geometry modeling and parameterization, a three-dimensional finite element model for structural mechanics, and an unsteady panel method for fluid dynamics. The approach is tested by applying it to the optimization of a pre-existing eel-inspired soft robot. Model parameters are estimated from existing experimental data, and two control co-design optimizations, with high-level and multilevel shape parameterizations, are performed to minimize energy cost. The optimized actuator module is manufactured, and used to collect additional data for re-estimating the structural model parameters. The optimization is performed again with the updated model parameters, showing a simulated energy cost reduction of 45% and the prescribed 128% speed increase compared to the baseline design with optimized control and updated model parameters. These results demonstrate the potential of the proposed optimization approach to advance the performance of anguilliform-swimming soft fluidic robots.
This paper develops a Distributed Energy Management System (EMS) to optimally allocate electric and thermal power production in a polygenerative microgrid. The EMS problem is formulated as a multiperiod convex optimiz...
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This paper develops a Distributed Energy Management System (EMS) to optimally allocate electric and thermal power production in a polygenerative microgrid. The EMS problem is formulated as a multiperiod convex optimization problem and solved using AL-SODU, a new distributed algorithm based on the augmented Lagrangian method with second order dual updates. The proposed AL-SODU algorithm significantly outperforms state of the art algorithms employing first order dual updates, with 15-times speedup in convergence speed. A case study of the EMS based on AL-SODU is conducted on the Smart Polygeneration Microgrid (SPM) located on the Savona Campus of University of Genova (Italy). The EMS determines the optimal schedules for electric and thermal power plants every 15-minutes. This real time scheduling of the microgrid is enabled by the Al-SODU algorithm, which solves the scheduling problem in 1.86s.
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