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Penetrator Penetrating Lunar Soil: Accurate Modeling and Parameter Analysis

AIAA JOURNAL 2023年第9期61卷 4195-4209页

作者： Luo, Haitao Fan, Chaohui Li, Yuxin Liu, Guangming Liu, Ziyang Chinese Acad Sci Shenyang 110016 Peoples R China

This paper focuses on how to establish an accurate numerical model of penetrator penetration into the lunar soil and study the process of penetration. The lunar soil simulant was prepared according to published literature, and its plastic parameters were obtained by triaxial compression test. To determine the material model and parameters of the lunar soil simulant in numerical simulation, the corresponding numerical simulation was carried out for the triaxial test. Under the comprehensive consideration of accuracy and computational efficiency, the applicability of four numerical algorithms, including finite element method (FEM), arbitrary Lagrangian-Eulerian, smoothed particle hydrodynamics (SPH), and SPH-FEM, in the penetration simulation is evaluated. Finally, SPH-FEM is the optimal algorithm for the numerical simulation of the penetrator penetrating lunar soil. The convergence of the penetration model is tested. Finally, an accurate numerical model of the penetrator penetrating lunar soil is obtained. Then, the effects of incident velocity, incident angle, and angle of attack on penetration performance are studied, respectively, which provide reference for the design and process control of the penetrator project.

关键词： Smoothed Particle Hydrodynamics Arbitrary Lagrangian Eulerian Discrete Element Method Aerodynamic Performance Mechanical Testing optimization algorithm Projectiles Internal Friction Mechanical Properties Finite Element Software

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An optimal internal model proportional integral controller to improve pressure tracking profile of artificial ventilator

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MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING 2023年第7期61卷 1807-1820页

作者： Acharya, Debasis Das, Dushmanta Kumar Natl Inst Technol Nagaland Chumukedima India

Mechanical ventilator (MV) is a breathing support medical equipment used during medical surgery or in an intensive care unit (ICU) for critical patients to reduce the breathing work of the patient under ventilation. In this work, a piston-driven mechanical ventilator is studied. Such types of ventilators are generally used as anaesthesia ventilators with volume-controlled modes. A modern ventilator can operate in different modes, such as volume control, pressure control, or both. Pressure-controlled mode may be better suited for some cases, such as patients undergoing laparoscopic surgery, as compared to volume-controlled mode because it may increase compliance during pneumoperitoneum, enhance oxygenation, and lower the stress response postoperatively. The pressure profile of a PCV must exactly track the pressure profile of a patient under ventilation to avoid ventilator-induced diaphragmatic dysfunction. Therefore, an optimal internal model control base proportional integral (IMC-PI) controller is proposed. The optimum parameter of the filter component of the IMC-PI controller is found by an enhanced class topper optimization (ECTO) algorithm. The performance of the proposed controller is analyzed in different scenarios and compared with existing results.

关键词： Artificial ventilation system (AVS) optimization algorithm Pressure control ventilator (PCV) Positive end-expiratory pressure (PEEP) Internal model control (IMC)

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Comparative Study of optimization algorithms for SHEPWM Five-Phase Multilevel Inverter 8

Comparative Study of Optimization Algorithms for SHEPWM Five...

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8th IEEE International Conference on Power and Energy (PECon)

作者： Bin Bimazlim, Muhammad Aniq Shahmi Ismail, Baharuddin Aihsan, Muhammad Zaid Mazalan, Siti Khodijah Walter, Muhammad Sirajuddin Muhammad Azhar Rohani, Mohamad Nur Khairul Hafizi Univ Malaysia Perlis Ctr Excellence Renewable Energy CERE Sch Elect Syst Engn Pauh Putra Campus Arau 02600 Perlis Malaysia Univ Malaysia Perlis Fac Engn Technol Dept Elect Engn Technol Padang Besar 02100 Perlis Malaysia

ISBN: (纸本)9781728170688

Conversion of DC to AC is widely used as an essential need for the power system to harness renewable power source in this era. Multilevel inverter is a mechanism which capable of harnessing these renewable energies. Unfortunately, harmonics occur in the system due to distortions and causing much unwanted problems at the power output. Therefore, the elimination of harmonics and reduce Total Harmonics Distortion (THD) are needed to maintain good power output. Application of Selective Harmonics Elimination Pulse Width Modulation ( SHEPWM) can be used in the multilevel inverter to solve the problem. In this paper, optimization algorithms such as Particle Swarm optimization (PSO), Whale optimization algorithm (WOA) and Sine Cosine algorithm (SCA) were applied for finding suitable switching angle for SHEPWM. The calculated switching angle was applied into seven-level fivephase multilevel inverter for various modulation indexes. In addition, the simulation of the multilevel inverter also done using PSIM software. The results show that the selective lower order harmonics, 3rd and 7th are completely eliminated for all three algorithms. In addition, the time taken for newly discovered algorithms to find switching angles for seven-level five-phase inverter is faster compared to PSO.

关键词： Multilevel inverter optimization algorithm SHEPWM PSO WOA SCA

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Optimal Torque Sharing Function Control for Switched Reluctance Motors Based on Active Disturbance Rejection Controller

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IEEE-ASME TRANSACTIONS ON MECHATRONICS 2023年第5期28卷 2600-2608页

作者： Feng, Liyun Sun, Xiaodong Yang, Zebin Diao, Kaikai Jiangsu Univ Automot Engn Res Inst Zhenjiang 212013 Peoples R China Jiangsu Univ Sch Elect & Informat Engn Zhenjiang 212013 Peoples R China

In this article, an optimal torque sharing function (TSF) control method incorporated with improved linear active disturbance rejection control (LADRC) and modified coyote optimization algorithm (MCOA) is introduced and applied in switched reluctance motors (SRMs). First, the piecewise TSF is employed to reduce the torque ripple, which exhibits little effects on the rate of current change and the current peak value. The improved linear extended state observer with the variable gain in speed controller using LADRC is designed to guarantee better antidisturbance ability and torque ripple reduction simultaneously. Then, the MCOA is introduced to automatically tune the parameters including the turn-on angle, conduction angle, and coefficients for better comprehensive performances. Finally, comparisons among the conventional TSF with LADRC, the piecewise TSF with LADRC, and the proposed TSF with improved LADRC are conducted both in the simulations and experiments. The results indicate that the proposed method behaves best in aspects of torque ripple suppression and anti-interference ability among the three methods.

关键词： Active disturbance rejection control (ADRC) optimization algorithm switched reluctance motor (SRM) torque sharing function (TSF)

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Application of an intelligent method for hydrogen-based energy hub in multiple energy markets

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2023年第93期48卷 36485-36499页

作者： Li, Ziyuan He, Tao Farjam, Hashem Xiamen Inst Technol Business Sch Xiamen 361000 Fujian Peoples R China Wenzhou Vocat & Tech Coll Sch Intelligent Mfg Wenzhou 325000 Zhejiang Peoples R China Sun Life Co EED Baku Azerbaijan

Use of different energy carriers together, known as an energy hub, has been a hot topic of research. The hub manager manages the energy in the hub and supplies the energy demanded by the consumers. Herein, a multi-carrier energy storage system comprising a thermal energy storage system, ice storage system, and hydrogen storage system is considered for a multi-carrier energy system to exploit their economic benefits. The proposed combined cooling, heating and electricity microgrid not only participates in the electricity, gas and heat market to meet the needs of electricity, heating and cooling, but also can use the new hydrogen power technology used in the hydrogen storage system to increase the efficiency of the whole system participate in the market. In addition, a multienergy demand response model is used as a new concept of demand response on electrical and thermal loads, which provides more options for multi-energy end users in energy management policies. To cover the uncertainty of the existence of different energy sources in the used model and the price of electricity, a new method has been used. The LHS sampling is used to develop diverse scenarios, and the backward scenario reduction method is adopted to decrease the number of scenarios. To solve the objective function and optimization, the metaheuristic whale algorithm improved by a local search algorithm is utilized. The main goal is to reduce the operation costs of the multi-energy carrier system. The obtained results show that the hydrogen storage utilization and multi-energy demand response can reduce the system operation cost by 6% for the studied experimental system. Furthermore, as the uncertainty budget increased, the total cost of operations increased by 10%. This is because the level of planning conservatism increases with each increase in the uncertainty budget. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Energy hub optimization algorithm Demand response Multi -carrier energy

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Duality-Based Near-Fuel-Optimal Impulsive Trajectory Computation for Spacecraft Rendezvous Under Perturbations

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2023年第5期46卷 871-884页

作者： Kim, Youngkwang Park, Sang-Young Kim, Pureum Yonsei Univ Dept Astron Astrodynam & Control Lab Seoul 03722 South Korea Yonsei Univ Dept Astron Seoul 03722 South Korea

In this study, a novel impulsive trajectory optimization algorithm for near-fuel-optimal rendezvous under perturbations is presented. The algorithm, called algorithm for impulsive rendezvous trajectory optimization under perturbations (AIRTOP), is designed such that the accuracy of rendezvous constraints is improved as much as possible while retaining the first-order optimality, under high-fidelity dynamics models that encompass various orbital perturbations (e.g., nonspherical gravity, air drag, luni-solar gravity, and solar radiation pressure). To eliminate rendezvous constraint errors, AIRTOP solves the linearized impulsive rendezvous problem recursively using the nonsingular dual-primal optimization algorithm. To improve the computational efficiency, AIRTOP applies the approximate analytical gradient of the constraint error norm during its error elimination process. We present three numerical simulations near circular and elliptical orbits. The simulation results show that i) AIRTOP can successfully solve impulsive rendezvous problems under realistic orbital perturbations with minimal user intervention, and ii) it can generate more fuel-efficient solutions in similar or shorter computation time than two other methods, namely, the differential corrector of the General Mission Analysis Tool and the global optimization approach, which can also take complex perturbations into account.

关键词： Hohmann Transfer Orbit optimization algorithm Spacecraft Rendezvous Impulsive Trajectory optimization Orbital Perturbations

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Stochastic energy scheduling in microgrid with real-time and day-ahead markets in the presence of renewable energy resources

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SOFT COMPUTING 2023年第22期27卷 16881-16896页

作者： Hai, Tao Zhou, Jincheng Latifi, Mohsen Qiannan Normal Univ Nationalities Sch Comp & Informat Duyun 558000 Guizhou Peoples R China Huaiyin Inst Technol Fac Elect Informat Engn Huaian Jiangsu Peoples R China Guizhou Univ State Key Lab Publ Big Data Guiyang 550025 Guizhou Peoples R China Key Lab Complex Syst & Intelligent Optimizat Guizh Duyun 558000 Peoples R China Key Lab Complex Syst & Intelligent Optimizat Qiann Duyun Peoples R China Solar Energy & Power Elect Co Ltd Tokyo Japan

Renewable resources are a crucial component in power system research within contemporary intelligent power systems. It is imperative that they are given meticulous consideration. Microgrids (MGs) have emerged as a solution to facilitate the integration of renewable energy sources on a large scale. The incorporation of power production innovations that exhibit high levels of unpredictability in their generation would have a notable impact on the management of power resource planning within microgrids. Therefore, it is imperative to implement efficient power management mechanisms in microgrids. This study introduces a scheduling arrangement for a microgrid (MG) that includes a solar power unit (PV), which operates on a day-ahead basis. This paper explores the effects of various weather variables on the power generated by photovoltaic units and the optimum scheduling of microgrids. The present study employs the modified fluid search optimization algorithm to address the challenge of optimum management of energy in a microgrid connected to the grid that is characterized by a high level of unpredictability. The simulation results of the study indicate that the implementation of a photovoltaic model in an actual setting enhances the precision of the system for managing energy and reduces the overall operational costs of the interconnected microgrid. The algorithm under focus has been evaluated on a standard MG. The method under consideration has been executed on the MATLAB/Simulink computational environment and its efficacy has been evaluated.

关键词： Microgrid optimization algorithm PV Green energy Energy management

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Transformer-Based Tight Constraint Prediction for Efficient Powered Descent Guidance

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2025年第5期48卷 1054-1070页

作者： Briden, Julia Gurga, Trey Johnson, Breanna Cauligi, Abhishek Linares, Richard MIT Dept Aeronaut & Astronaut 125 Massachusetts Ave Cambridge MA 02139 USA NASA Johnson Space Ctr Flight Mech & Trajectory Design Branch EG52101 E NASA Pkwy Houston TX 77058 USA CALTECH Jet Prop Lab Pasadena CA 91109 USA

In this work, we present transformer-based powered descent guidance (T-PDG), a scalable algorithm for reducing the computational complexity of the direct optimization formulation of the spacecraft powered descent guidance problem. T-PDG uses data from prior runs of trajectory optimization algorithms to train a transformer neural network, which accurately predicts the relationship between problem parameters and the globally optimal solution for the powered descent guidance problem. The solution is encoded as the set of tight constraints corresponding to the constrained minimum-cost trajectory and the optimal final landing time. By leveraging the attention mechanism of transformer neural networks, large sequences of time series data can be accurately predicted when given only the spacecraft state and landing site parameters. When applied to the real problem of Mars-powered descent guidance, T-PDG reduces the time for computing the 3-degree-of-freedom fuel-optimal trajectory when compared to lossless convexification, improving solution times by up to an order of magnitude. A safe and optimal solution is guaranteed by including a feasibility check in T-PDG before returning the final trajectory.

关键词： Electric Power Conversion Powered Descent Initiation Convolutional Neural Network Pontryagin's Minimum Principle Planets Computing and Informatics Proportional Integral Derivative Structural Kinematics and Dynamics Numerical Interpolation optimization algorithm

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TriTSA: Triple Tree-Seed algorithm for dimensional continuous optimization and constrained engineering problems

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ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE 2021年 104卷 104303-104303页

作者： Jiang, Jianhua Liu, Yutong Zhao, Ziying Jilin Univ Finance & Econ Sch Management Sci & Informat Engn Changchun 130117 Peoples R China Jilin Univ Finance & Econ Jilin Prov Key Lab Fintech Changchun 130117 Peoples R China

Tree-Seed algorithm (TSA) is a meta-heuristic optimization algorithm with good performance in solving continuous optimization problems. However, there is an imbalance between its exploration and exploitation when solving complex problems, mainly lack exploration. To overcome this problem, this paper proposes two tree migration mechanisms: triple-learning-based migration mechanism and sine-random-distribution migration mechanism. The target tree position is migrated by learning from the first three trees in the current iteration. The sine function is added to the tree migration formula to enhance the randomness of tree distribution. In order to verify these migration mechanisms, Triple Tree-Seed algorithm (TriTSA) has been proposed and compared with TSA on 30 well-known test functions from IEEE CEC 2014. In addition, STSA, SCA, PSO, ABC, Jaya, and TLBO are adopted in some comparative experiments on different dimensions. The experiments show that the tree migration mechanism can improve the optimization capability of the original algorithm effectively. On all 30 benchmark test functions, TriTSA outperforms TSA on 10, 30, 50, and 100 dimensions by 70%, 90%, 90%, and 97% respectively. Finally, the proposed TriTSA is compared with TSA, ABC, PSO, and SCA on solving two classical engineering design problems. It is proved that the proposed algorithm is more applicable in solving practical problems.

关键词： optimization algorithm Tree-Seed algorithm Triple Tree-Seed algorithm Continuous optimization problems

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Developing an experimental-computational workflow to study the biomechanics of the human conventional aqueous outflow pathway

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ACTA BIOMATERIALIA 2023年第1期164卷 346-362页

作者： Karimi, Alireza Khan, Shanjida Razaghi, Reza Rahmati, Seyed Mohammadali Gathara, Michael Tudisco, Erika Aga, Mini Kelley, Mary J. Jian, Yifan Acott, Ted S. Oregon Hlth & Sci Univ Casey Eye Inst Dept Ophthalmol Portland OR 97239 USA Oregon Hlth & Sci Univ Dept Biomed Engn Portland OR USA Univ Alabama Birmingham Dept Ophthalmol & Visual Sci Birmingham AL USA Georgia Inst Technol Sch Biol Sci Atlanta GA USA Univ Alabama Birmingham Dept Comp Sci Birmingham AL USA Lund Univ Div Geotech Engn Lund Sweden Oregon Hlth & Sci Univ Sch Dent Dept Integrat Biosci Portland OR USA Oregon Hlth & Sci Univ Sch Med Dept Chem Physiol & Biochem Portland OR USA

The aqueous humor actively interacts with the trabecular meshwork (TM), juxtacanalicular tissue (JCT), and Schlemm's canal (SC) through a dynamic fluid-structure interaction (FSI) coupling. Despite the fact that intraocular pressure (IOP) undergoes significant fluctuations, our understanding of the hypervis-coelastic biomechanical properties of the aqueous outflow tissues is limited. In this study, a quadrant of the anterior segment from a normal human donor eye was dynamically pressurized in the SC lumen, and imaged using a customized optical coherence tomography (OCT). The TM/JCT/SC complex finite element (FE) with embedded collagen fibrils was reconstructed based on the segmented boundary nodes in the OCT images. The hyperviscoelastic mechanical properties of the outflow tissues' extracellular matrix with embedded viscoelastic collagen fibrils were calculated using an inverse FE-optimization method. There-after, the 3D microstructural FE model of the TM, with adjacent JCT and SC inner wall, from the same donor eye was constructed using optical coherence microscopy and subjected to a flow load-boundary from the SC lumen. The resultant deformation/strain in the outflow tissues was calculated using the FSI method, and compared to the digital volume correlation (DVC) data. TM showed larger shear modulus (0.92 MPa) compared to the JCT (0.47 MPa) and SC inner wall (0.85 MPa). Shear modulus (viscoelastic) was larger in the SC inner wall (97.65 MPa) compared to the TM (84.38 MPa) and JCT (56.30 MPa). The conventional aqueous outflow pathway is subjected to a rate-dependent IOP load-boundary with large fluctuations. This necessitates addressing the biomechanics of the outflow tissues using hyperviscoelastic *** of significance While the human conventional aqueous outflow pathway is subjected to a large-deformation and time -dependent IOP load-boundary, we are not aware of any studies that have calculated the hyperviscoelastic mechanical properties of

关键词： Trabecular meshwork Juxtacanalicular tissue Schlemm's canal Hyperviscoelastic Finite element method optimization algorithm

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