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Chinese control and Decision Conference, CCDC

作者： Songshuo Lu Yanjie Li Zihan Liu the Department of Control Science and Engineering Harbin Institute of Technology (Shenzhen) Shenzhen China

Quadrotors usually suffer various external disturbances when flying in the real-world environment. A robust and adaptive controller is required to maintain the stability. Traditional control methods require to handcraft the model of the disturbance, making them difficult to adapt to various scenarios. In this paper, a reinforcement-learning-based (RL-based) quadrotor control method is proposed to counter external disturbances. By using Proximal Policy Optimization (PPO), a policy network is trained to directly output the desired 3-axis Euler angles and throttle for feedback control. In simulated experiments and real-world experiments, we show quantitative results via the comparison between the traditional method and our proposed method.

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An Improved Classification Method of Ultrasonic Thyroid Standard Planes Based on Bayesian Optimization of Multi-Feature Parameters for Portable Application

An Improved Classification Method of Ultrasonic Thyroid Stan...

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Chinese control Conference (CCC)

作者： Xinran Li Xin Zhang Chenyang Fan Yi Shen Department of Control Science and Engineering Harbin Institute of Technology Harbin PR China School of Mathematics Harbin Institute of Technology Harbin PR China

In recent years, computer aided technology is increasingly applied to the classification of thyroid ultrasonic planes for calculating the thyroid volume, and then the disease can be diagnosed by its volume. However, these methods requiring greater computational power are not suitable for the portable ultrasound system with limited performance. Based on Bayesian optimization of multi-feature parameters, an improved classification method of ultrasonic thyroid planes is proposed in this paper for low computational complexity with a high classification accuracy. Local Binary Patterns (LBP) feature and Gray Level Co-occurrence Matrix (GLCM) feature are selected by the analysis of image texture information, and then the combined feature is utilized to investigate the effectiveness of different classifiers. Furthermore, Bayesian optimization is employed to obtain the optimal parameters of the combined feature for improving classification results, and the accuracy can reach up to 96.81%. The results clearly illustrate that the improved method is effective in classifying the ultrasonic thyroid planes under a low computational complexity.

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Fuel-Optimal Spacecraft Rendezvous Mission Planning Method Considering Orbital Perturbation

Fuel-Optimal Spacecraft Rendezvous Mission Planning Method C...

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Chinese control Conference (CCC)

作者： Jiukai Zhu Wudong Deng Leixiang Sun Yanning Guo Department of Control Science and Engineering Harbin Institute of Technology Harbin China Shanghai Institute of Satellite Engineering Shanghai China

A fuel-optimal spacecraft rendezvous mission planning method considering orbital perturbation is proposed to address the fuel consumption problem of spacecraft completing rendezvous missions. Firstly, considering the constraints of total mission time and desired position, a model of orbital perturbation spacecraft considering non-spherical and atmospheric drag is constructed, and the adaptation function of fuel consumption for single-loop Lambert transfer considering orbital perturbation is designed. Based on this fitness function, an improved particle swarm optimization algorithm is designed to determine the first applied impulse time, the second applied impulse time, and the rendezvous time in the rendezvous mission planning, and then solve the two applied impulse sizes with the minimum fuel consumption to complete the spacecraft rendezvous mission. Finally, simulation experiments with a set of spacecraft rendezvous missions are conducted to verify the practicality and effectiveness of the method.

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A robust protocol to compute wind load coefficients of telecommunication towers and antennas using numerical simulation for risk and resilience assessment

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Resilient Cities and Structures 2024年第1期3卷 66-83页

作者： Mohanad Khazaali Liyang Ma Keivan Rokneddin Matteo Mazzotti Paolo Bocchini Research Engineer Extreme Event Solutions at VeriskLafayette City CenterBostonMA 02111USA Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbin 150090PR China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin 150090PR China Senior Research Scientist RenaissanceRe Risk SciencesUSA Research Associate P.M.Rady Department of Mechanical EngineeringUniversity of Colorado Boulder1111 Engineering Dr UCB 427BoulderCO 80309USA Professor Dept.of Civil and Environmental EngineeringLehigh University117 ATLSS DrBethlehemPA 18015-4729.USA Director Catastrophe Modeling CenterLehigh UniversityBethlehemPAUSA

An accurate estimation of wind loads on telecommunication towers is crucial for design,as well as for perform-ing reliability,resilience,and risk *** particular,drag coefficient and interference factor are the most significant factors for wind load *** tunnel tests and computational fluid dynamics(CFD)are the most appropriate methods to estimate these *** wind tunnel tests are generally preferred in practice,they require dedicated facilities and personnel,and can be expensive if multiple configurations of tower panels and antennas need to be tested under various wind directions(e.g.,fragility curve development for system resilience analysis).This paper provides a simple,robust,and easily accessible CFD protocol with widespread applicability,offering a practical solution in situations where wind tunnel testing is not feasible,such as complex tower configurations or cases where the cost of running experiments for all the tower-antennas configurations is prohibitively *** turbulence models,structural and fluid boundary conditions and mesh types are tested to provide a streamlined CFD modeling strategy that shows good convergence and balances accuracy,computational time,and *** protocol is calibrated and validated with experimental studies available in the *** demonstrate the capabilities of the protocol,three lattice tower panels and antennas with different configurations are analyzed as *** protocol successfully estimates the drag and lateral wind loads and their coefficients under different wind *** differences are observed between the esti-mated wind loads with this protocol and those computed by a simple linear superposition used in most practical applications,indicating the importance of tower-antenna ***,as expected,the wind loads recom-mended by design codes overestimate the simulated *** importantly,the telecommunication design codes inadequate

关键词： Generalized CFD protocol Lattice tower Tower panel Microwave antenna Wind coefficients Tower-antenna interaction

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A Numerical Analysis of Pressure Characteristics in the Deflector Jet Pilot Stage Valve with an Innovative Deflector Deflection

SSRN

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SSRN 2024年

作者： Li, Songjing Saha, Bijan Krishna Shakib, Md. Shah Najmus Peng, Jinghui Jihan, Jahidul Islam Department of Fluid Control and Automation Harbin Institute of Technology Harbin150001 China Department of Mathematics Faculty of Science and Engineering University of Barishal Barishal8254 Bangladesh Harbin Institute of Technology China

Electric-hydraulic servo-valves are extensively used in the aerospace, mechanical, and aerodynamics industries to control missile wings or airplanes precisely. Aiming to reduce undesired flow phenomena inside the deflector jet pilot valve, innovative deflections of deflector are proposed in this paper. A numerical analysis is performed using STAR CCM+ to investigate the pressure and flow characteristics inside the pilot stage of deflector jet servo-valve. For observing the pressure, cavitation and flow characteristics, the Eulerian multi-phase model, VOF phase interaction, and realizable model for the turbulent flow are used during numerical simulations. The supply and outlet pressure are kept at 24 MPa and 1 MPa, respectively. To verify the calculated numerical results for turbulent flows, the velocity distribution to the V-groove exit of the deflector jet pilot stage is calculated and discussed with the theoretical results. The numerically calculated results show good agreement with published analytical results. The result shows that by the innovative rotation of the deflector both in clockwise and anti-clockwise directions, significant pressure in the receivers is obtained than traditionally moving deflector to the left and right for the same supply pressure. Moreover, when the deflector is positioned clockwise or anti-clockwise by 5 degrees, less cavitation is observed than in the traditional model. The key finding of this paper shows that innovative structural optimization of the amplifier disk and deflector is of utmost importance. © 2024, The Authors. All rights reserved.

关键词： Computational fluid dynamics

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Dynamic Event-Triggered Fixed-Time Consensus Analysis of Multi-Agent Systems Under Input Delays and Switching Topologies

Dynamic Event-Triggered Fixed-Time Consensus Analysis of Mul...

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On-Line Conference (ONCON), Industrial Electronics Society Annual

作者： Yu Zhang Yajing Li Guangtao Ran Hao Yu Guangfu Ma Department of Automation Harbin Institute of Technology (Shenzhen) Shenzhen China Shanghai Institute of Aerospace System Engineering Shanghai China Department of Control Science and Engineering Harbin Institute of Technology Harbin China School of Automation Beijing Institute of Technology Beijing China

ISBN: (数字)9798331540319

ISBN: (纸本)9798331540326

This paper proposes a dynamic event-triggered control method for first-order multi-agent systems with input delays and disturbances under switching topologies. The controller design and its properties of dynamic event-triggered fixed-time consensus are presented in detail. Furthermore, agents can achieve consensus in a fixed time for any initial conditions and topologies that comply with the control protocol. Zeno behavior is avoided. Simulation examples demonstrate the effectiveness of the proposed algorithm and simulate scenarios in which the communication environment deteriorates due to external disturbances affecting the MASs.

关键词： Industrial electronics Protocols Event detection Switches control systems Stability analysis Topology Delays Numerical stability Multi-agent systems

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Interfacial Heterogeneous Microstructure and Subsequent Machinability of 316L/CuSn10 Bimetallic Structure Manufactured by Laser Powder Bed Fusion

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Additive Manufacturing Frontiers 2024年第3期3卷 100-112页

作者： Jie Chen Zhongpeng Zheng Di Wang Guijun Bi Yuchao Bai Institute of Intelligent Manufacturing Guangdong Academy of SciencesGuangzhou510070China Guangdong Key Laboratory of Modern Control Technology Guangzhou510070China State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing100084China School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou510640China School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen518052China

Additively manufactured bimetallic structures combine the advantages of dissimilar materials and can achieve localized properties through a customized composition ***,additively manufactured parts may still lack the dimensional accuracy and surface integrity essential for precision mechanical assemblies that the post-machining process can ***,this study aims to systematically investigate the microstructure and machinability of 316L/CuSn10 bimetallic structures fabricated using laser powder bed *** results show that the fusion zone of the bimetallic structure had refined grains of microscale size owing to the mixture of the primary elements of the bimetals,which resulted in the highest microhardness of 3.4 *** difference in microstructure and microhardness between the single-material and fusion zones also causes significant differences in the cutting response during the ultraprecision *** 316L stainless steel side exhibited the highest cutting force and more severe material accumulation in the *** cutting force drops when cutting through the fusion zone,with an observable fracture in the chips and separation of dissimilar materials on the machined grooves,indicating that the heterogeneous properties of additively manufactured 316L/CuSn10 bimetallic structures pose challenges to the improvement of surface *** simulation results also showed that stress accumulation occurred in the tool path through the fusion zone owing to the higher yield strength and hardness of stainless steel,indicating that lower cutting speeds and depths of cut are favorable for reducing cutting force and improving surface *** study provides deep insight into the microstructure evolution mechanism and a theoretical basis for improving the surface quality of additively manufactured bimetallic structures using an ultraprecision machining process.

关键词： Laser powder bed fusion Bimetallic structure Heterogeneous microstructures Ultra-precision machining Machinability

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A Distributed Reactive Power Sharing Approach in Microgrids with Improved Droop control

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CSEE Journal of Power and Energy Systems 2021年第6期7卷 1238-1246页

作者： Xinsheng Wang Jiancheng Zhang Mingli Zheng Lingyu Ma the Department of Control Science and Engineering Harbin Institute of TechnologyNo.2 Culture West RoadWeihaiChina the Department of Information Engineering Shandong Management UniversityNo.3500 Dingxiang RoadJinanChina

Conventional droop control causes frequency and voltage deviations(from rated value)in a inverter-intensive microgrid(MG),and the reactive power sharing cannot be obtained when the communication structure of the MG or load suddenly *** with a centralized control and droop control scheme,a distributed hierarchical control structure of the MG can overcome the limitation of communication and realize reactive power *** this paper,an improved droop control is adopted,which is based on the hierarchical control *** hierarchical control structure consists of zerolevel control,primary control and a proposed secondary ***,the secondary controller is modeled,and the MG system composed of distributed generators(DGs)is considered as a multi-agent *** secondary controller can make up for the shortcomings of the droop controller and adjust the frequency and voltage to their rated ***,the reference voltage and frequency of the zero-level control are calculated,and combined with the primary *** zero-level control and primary control can make the voltage and frequency of the MG run stably and provide reference voltage for the ***,the stability of the system is proved by the theory of multi-agent consistency.A simulation system is established in the Matlab/Simulink environment,and the results show the effectiveness of the proposed controller.

关键词： Consensus distributed generator hierarchical control microgrid reactive power sharing

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Design and Analysis of Extensible Cable-Driven Continuum Robot with Variable Stiffness

Design and Analysis of Extensible Cable-Driven Continuum Rob...

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2023 IEEE International Conference on Robotics and Biomimetics, ROBIO 2023

作者： Seleem, Ibrahim A. Naeem, Mohamed A. Ishii, Hiroyuki Waseda University Department of Modern Mechanical Engineering Japan Menoufia University Faculty of Electronic Engineering Department of Industrial Electronics and Control Engineering Egypt Harbin Institute of Technology School of Mechanical and Electrical Engineering Department of Mechatronics Engineering China South Valley University Faculty of Engineering Department of Mechatronics and Robotics Engineering Egypt

ISBN: (纸本)9798350325706

Extensible Soft Robots (ESRs) have increasingly attracted attention, especially in tight and complex environments, owing to their dexterity, and wide reachable workspaces relative to their volume. The existing actuation methods of ESR still suffer from challenges including large dimensions, expensive, complex modeling and control, and limited payload capacity. In this paper, we introduce a novel design for a lightweight, extensible and variable stiffness soft robot-based cable-driven actuation without backbone. The design composes of one section with three segments based on semi-octagon honeycomb structure, wherein the middle segment acts like a soft spring to provide extension feature. Additionally, the top and bottom segments have identical structure with two honeycomb patterns embedded within each other to improve the stiffness of the design. A design analysis is conducted to optimize the proposed structure with respect to stress and displacement. Additionally, a shape estimation approach is utilized to get accurate inference of the prototype's shape based on data acquired from a low-cost Inertial Measurement Unit (IMU) and Motion Capture System (MCS), and constant curvature assumption. A series of experiments including workspace reach-ability, repeatability, shape approximation and payload analysis are carried out to validate the proposed design. The results show that the prototype exhibits good compression/extension ratio up to 42% and 50% relative to its normal length, respectively. Moreover, its payload capability reaches to 565 grams. © 2023 IEEE.

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Removing microplastics from aquatic environments:A critical review

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Environmental Science and Ecotechnology 2023年第1期13卷 37-53页

作者： Yusheng Pan Shu-Hong Gao Chang Ge Qun Gao Sijing Huang Yuanyuan Kang Gaoyang Luo Ziqi Zhang Lu Fan Yongming Zhu Ai-Jie Wang School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin150090China State Key Laboratory of Urban Water Resource and Environment School of Civil&Environmental EngineeringHarbin Institute of Technology ShenzhenShenzhen518055China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhenChina Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) GuangzhouChina Key Laboratory of Environmental Biotechnology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085China

As one of the typical emerging contaminants,microplastics exist widely in the environment because of their small size and recalcitrance,which has caused various ecological *** paper summarizes current adsorption and removal technologies of microplastics in typical aquatic environments,including natural freshwater,marine,drinking water treatment plants(DWTPs),and wastewater treatment plants(WWTPs),and includes abiotic and biotic degradation technologies as one of the removal ***,numerous studies have shown that enrichment technologies have been widely used to remove microplastics in natural freshwater environments,DWTPs,and *** removal of microplastics via WWTPs is critical to reduce the release to the natural environment as a key connection point to prevent the transfer of microplastics from society to natural water *** technology has outstanding pre-degradation effects on microplastics,and the isolated microbial strains or enriched communities can degrade up to 50%or more of pre-processed ***,more research focusing on microplastic degradation could be carried out by combining physical and chemical pretreatment with subsequent microbial *** addition,the current recovery technologies of microplastics are introduced in this *** is incredibly challenging because of the small size and dispersibility of microplastics,and the related technologies still need further *** paper will provide theoretical support and advice for preventing and controlling the ecological risks mediated by microplastics in the aquatic environment and share recommendations for future research on the removal and recovery of microplastics in various aquatic environments,including natural aquatic environments,DWTPs,and WWTPs.

关键词： Aquatic environment Enrichment and removal Microplastics Wastewater treatment plants

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