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IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： Yuchen Zhou Liang Yan Lijia Ge Ahmed Aboelhassan School of Automation Science and Electrical Engineering Beihang University Beijing China Science and Technology on Aircraft Control Laboratory Beihang University Beijing China Ningbo Institute of Technology Beihang University Ningbo China Electrical and Control Engineering Department College of Engineering & Technology Arab Academy For Science Technology and Maritime Transport (AASTMT) Alexandria Egypt Key Laboratory of More Electric Aircraft Technology of Zhejiang Province University of Nottingham Ningbo China Ningbo China

ISBN: (纸本)9781665409858

The performance of the permanent magnet synchronous motors can be evaluated through several factors including power losses, harmonic content, and torque ripples. One of the possible ways to enhance the density of the output power and torque is by implementing the Halbach magnet array. It can improve the output performance of the electric machine by increasing the fundamental amplitude of the magnetic flux density and reducing the harmonic contents. So, a Modified Segmented Halbach Magnet Arrays (MSHMA) configuration is proposed and compared to the conventional topology in this paper. The static magnetic field distributions of the given Halbach magnet array structures are analyzed by the Finite Element Method (FEM) for a surface-mounted Permanent Magnet Synchronous Motor (PMSM). Also, the harmonic components of both configurations are evaluated by the Fast Fourier Transform (FFT). The results indicate that the MSHMA can significantly improve the output performance of the electric machine by increasing the fundamental amplitude of the magnetic flux density and reducing the harmonic contents. The electric machines model composed of the MSHMA and conventional topology are also simulated by the FEM, and the air-gap magnetic flux density distribution under the armature reaction is analyzed. The results show the MSHMA’s capability to improve the output performance of the considered PMSM model, and a reduction in the torque ripple from 4.4 % to 1.8 %.

关键词： Magnetic flux density Torque Electric machines Atmospheric modeling Harmonic analysis Permanent magnet motors Finite element analysis

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Scalable parallel evolutionary optimization on high performance computing

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Aerospace Traffic and Safety 2024年第2期1卷 93-102页

作者： Chen Jin Daren Zheng Shuke He Ao Cheng Gang Liu Key Laboratory of Civil Aviation Emergency Science&Technology CAACNanjing University of Aeronautics and AstronauticsNanjingChina Zhejiang Scientific Research Institute of Transport HangzhouChina School of Computer Science and Information Technology RMIT UniversityMelbourneAustralia Key Laboratory of Aircraft Environment Control and Life Support MIITNanjing University of Aeronautics and AstronauticsNanjingChina Zhejiang Jiande Institute of General Aviation HangzhouChina Zhejiang ATM Sub-Bureau.CAAC HangzhouChina

To improve the efficiency of evolutionary algorithms(EAs)for solving complex problems with large populations,this paper proposes a scalable parallel evolution optimization(SPEO)framework with an elastic asynchronous migration(EAM)*** addresses two main challenges that arise in large-scale parallel EAs:(1)heavy communication workload from extensive information exchange across numerous processors,which reduces computational efficiency,and(2)loss of population diversity due to similar solutions generated and shared by many *** EAM mechanism introduces a self-adaptive communication scheme to mitigate communication overhead,while a diversity-preserving buffer helps maintain diversity by filtering similar *** results on eight CEC2014 benchmark functions using up to 512 CPU cores on the Australian National Computational Infrastructure(NCI)platform demonstrate that SPEO not only scales efficiently with an increasing number of processors but also achieves improved solution quality compared to state-of-the-art island-based EAs.

关键词： Parallel evolutionary algorithm High performance computing(HPC) Computational efficiency Asynchronous migration

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Analysis of Oil Viscous Drag Loss of Deep-sea Motor Based on CFD Method

Analysis of Oil Viscous Drag Loss of Deep-sea Motor Based on...

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IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： Jiatong Liu Liang Yan Xinghua He Yuchen Zhou Zihao Yu School of Automation Science and Electrical Engineering Beihang University Beijing China Science and Technology on Aircraft Control Laboratory Beihang University Beijing China Ningbo Institute of Technology Beihang University Ningbo China

ISBN: (纸本)9781665409858

Oil viscous drag loss needs to be taken into consideration in the design of deep-sea oil-filled motors. There are many factors affecting viscous drag loss and the analytical formula of oil viscous drag loss is not suitable for the calculation of turbulent flow field. Based on the above problems, a CFD model of the air gap flow field is established in this paper and the influence of air-gap thickness, speed of motor, viscosity of oil, and rotor eccentricity on oil viscous drag loss is analyzed. The results show that oil viscous drag loss is negatively correlated with air gap thickness, temperature and positively correlated with rotor eccentricity and motor speed.

关键词： Viscosity Industrial electronics Analytical models Oils Drag Atmospheric modeling Air gaps

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Cooperative Task Reconstruction Allocation for Unmanned Swarm Systems Based on MGGA and SAA

Cooperative Task Reconstruction Allocation for Unmanned Swar...

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International Conference on control and Automation (ICCA)

作者： Jintong Yu Yongzhao Hua Xiwang Dong Qingdong Li Zhang Ren Institute of Artificial Intelligence Beihang University Beijing P.R. China Institute of Unmanned System Beihang University Beijing P.R. China Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical Engineering Beihang University Beijing P.R. China

ISBN: (数字)9798350354409

ISBN: (纸本)9798350354416

Multi-unmanned agent collaboration technology is a key aspect of operations. How to reasonably assign tasks to unmanned agents before operations to maximize the overall benefits is a long-standing problem for researchers. This study systematically addresses the above issues and establishes a multi-agent task reconstruction model based on the reconnaissance, strike and assessment task background. This model includes two types of task allocation algorithms. One is task pre-allocation, which is a static task allocation before task execution. A Multi-Gene Genetic Algorithm (MGGA)is proposed for this purpose. The other is Sequential Auction Algorithm(SAA), which deals with the reallocation of tasks in response to unexpected situations during task execution. Experimental results show that, compared with other algorithms, MGGA can get the lowest fitness value under various experimental conditions. Meanwhile, SAA can handle task reallocation problems caused by various dynamic events.

关键词： Heuristic algorithms Sociology System recovery Reconstruction algorithms Reconnaissance Resource management Time factors

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Performance Analysis of PMSM Based on Improved Trapezoidal Halbach Magnet Arrays

Performance Analysis of PMSM Based on Improved Trapezoidal H...

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IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： Zihao Yu Liang Yan Yuchen Zhou Jiatong Liu Xinghua He Ahmed Aboelhassan School of Automation Science and Electrical Engineering Beihang University Beijing China Science and Technology on Aircraft Control Laboratory Beihang University Beijing China Ningbo Institute of Technology Beihang University Ningbo China Electrical and Control Engineering Department College of Engineering & Technology Arab Academy For Science Technology and Maritime Transport (AASTMT) Alexandria Egypt Key Laboratory of More Electric Aircraft Technology of Zhejiang Province University of Nottingham Ningbo China Ningbo China

ISBN: (纸本)9781665409858

In this paper, a novel trapezoidal Halbach permanent magnet array is introduced to lessen the output torque ripple of a surface-mounted Permanent Magnet Synchronous Motor (PMSM). Finite Element Method (FEM), core loss, output torque, and torque ripple are examined. The harmonic components of the trapezoidal Halbach magnet arrays are analyzed by the Fast Fourier Transform (FFT). Additionally, a traditional trapezoidal Halbach magnet array-based 2D finite element model of the PMSM is also developed. The findings demonstrate the improved trapezoidal Halbach magnet array's capability to reduce the PMSM's torque ripple by lowering the intensity of the third harmonic of the air-gap flux density. In contrast to the PMSM employing traditional trapezoidal Halbach magnet arrays, the PMSM with the introduced trapezoidal Halbach arrays has a lower torque ripple by 11.84 % and a higher torque by 18.03%, while maintaining similar core loss.

关键词： Magnetic flux Electron traps Torque Magnetic cores Core loss Air gaps Harmonic analysis

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Time-Varying Formation Tracking control for Unmanned Aerial Vehicles: Theories and Applications

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IFAC-PapersOnLine 2022年第3期55卷 49-54页

作者： Qing Li Yongzhao Hua Xiwang Dong Zhang Ren School of Automation Science and Electrical Engineering Science and Technology on Aircraft Control Laboratory Beihang University Beijing 100191 P.R. China Institute of Artificial Intelligence Beihang University Beijing 100191 P.R. China

Time-varying formation tracking (TVFT) problems for unmanned aerial vehicles (UAVs) swarm systems with the leader’s unknown input are studied. The follower UAVs form an expected formation while tracking the leader UAV. According to the information of the neighboring UAVs, a TVFT control protocol is constructed. It’s proved by Lyapunov stability theory that the error of each follower UAV converge to a specified boundary, which means that the swarm system of UAVs can realize the practical TVFT. A platform consisting of five Tello quadrotors and ultrawideband (UWB) positioning technology is given. The effectiveness of the TVFT control protocol is verified on numerical simulation and Tello-UWB experiment platform.

关键词： Formation tracking control swarm system time-varying formation unmanned aerial vehicle(UAV)

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Switching GMM-HMM for Complex Human Activity Modeling and Recognition

Switching GMM-HMM for Complex Human Activity Modeling and Re...

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Chinese Automation Congress (CAC)

作者： Weiwei Qin Huai-Ning Wu School of Automation Science and Electrical Engineering Beihang University Beijing China Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical Engineering Beihang University Beijing China Peng Cheng Laboratory Shenzhen China

Complex human activities can be decomposed into primitive activities (PAs) that happen sequentially but may vary in order or frequency among different observation sequences. The Gaussian mixture model based hidden Markov model (GMM-HMM) is widely used for activity modeling but is only capable of modeling activities with fixed pattern trajectories. To overcome the drawback of GMM-HMM, a hierarchical structure is introduced to form the Switching Gaussian mixture model based hidden Markov model (S-GMMHMM), where PAs are treated as upper layer states and the continuous observation sequence emitted by each PA is modeled by a GMM-HMM. To ensure that the upper layer states correspond to real activities, a supervised algorithm is proposed for S-GMMHMM parameter estimation. For the purpose of less time complexity, a real-time activity recognition algorithm is proposed by computing activity posteriors recursively. Experiment results show that the proposed model outperforms GMM-HMM in activity recognition, while brings a notable reduction in time complexity.

关键词： Parameter estimation Computational modeling Hidden Markov models Switches Activity recognition Markov processes Real-time systems

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BiGAIL: Learning Intention-based Driving Policy from Multi-task Demonstrations

BiGAIL: Learning Intention-based Driving Policy from Multi-t...

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Chinese Automation Congress (CAC)

作者： Lin Huang Huai-Ning Wu School of Automation Science and Electrical Engineering Beihang University Beijing China Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical Engineering Beihang University Beijing China Peng Cheng Laboratory Shenzhen China

With the rapid development of traffic intelligence, autonomous driving technology has gradually attracted the interests of researchers. Behavioral decision-making is one of the most important parts of autonomous driving system (ADS). As a common solution, imitation learning (IL) provides a more natural and intuitive way of learning through the prior knowledge of experts. Generative adversarial imitation learning(GAIL), which is a branch of IL, is often used to learn the driving policy because of its robustness and capacity of handling large-scale problems. However, modal collapse caused by GAIL may make the generated policies lack diversity resulting in the failure of multi-task learning. In the paper, we propose an algorithm named as bidirectional generative adversarial imitation learning (BiGAIL) that allows the agent to learn the map between task intentions and driving policies, so as to achieve the goal of learning intention-based driving policy. Through simulation verification, the agent trained with BiGAIL is able to select the appropriate policy based on the current environment and learn different driving policies from multi-task demonstrations.

关键词： Learning systems Automation Decision making Multitasking Robustness Behavioral sciences Task analysis

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Impact Time and Angle control Guidance Based on Cubic Bézier Curves: Theory and Experiment

SSRN

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SSRN 2024年

作者： Li, Heng Lv, Xiaokang Yu, Jianglong Zhang, Kun Wang, Yanyan Dong, Xiwang Institute of Artificial Intelligence Beihang University Beijing100191 China School of Automation Science and Electrical Engineering Science and Technology on Aircraft Control Laboratory Beihang University Beijing100191 China Institute of Unmanned System Beihang University Beijing100191 China School of Astronautics Beihang University Beihang University Beijing100191 China National Key Laboratory of Complex System Control and Intelligent Agent Cooperation Beijing100074 China

A trajectory-shaping guidance strategy with constraints on impact time, impact angle, and maximum lateral acceleration is proposed based on a cubic Bézier curve fitting method. Firstly, an optimal guidance model is formulated, in which the Bézier curves are employed to fit the guidance trajectory, ensuring compliance with the required constraints. The manipulation transforms the optimal guidance problem into an optimal Bézier guidance trajectory design problem and a trajectory tracking problem. Then, by parameterizing the Bézier curves and analyzing the trajectory constraints in detail, the optimal Bézier guidance trajectory design is transformed into optimizing the control parameters of the Bézier curves. Moreover, a multi-layer zeroth-order Adam trajectory optimization algorithm based on general and fine tuning is introduced to determine the control parameters without relying on gradient information. Subsequently, a hyperbolic tangent vector field path tracking guidance algorithm is proposed to follow the designed trajectory and fulfill the guidance missions. Finally, numerical simulations and equivalent physical experiments verify the effectiveness of the proposed guidance strategy. © 2024, The Authors. All rights reserved.

关键词： Trajectories

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Mitigating Twice the Fundamental Frequency Ripple in Three-Phase to Single-Phase Power Converters through Improved DC Link Voltage control

Mitigating Twice the Fundamental Frequency Ripple in Three-P...

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Annual Conference of Industrial Electronics Society

作者： Lorenzo Carbone Meiqi Wang Gioele Baia Qilin Peng Alan J. Watson Power Electronics Machine and Control (PEMC) Research Institute University of Nottingham Nottingham United Kingdom Dept. Council of Science Technology and Society IUSS Advanced School of Pavia Pavia Italy Key Laboratory of More Electric Aircraft Technology of Zhejiang Province University of Nottingham Ningbo China Ningbo China

ISBN: (数字)9781665464543

ISBN: (纸本)9781665464550

Single phase grid connected converters suffer from the well-known pulsation of power at twice the fundamental frequency. This ripple affects the current in the three-phase AC system through the DC link voltage control, leading to inefficiencies and potential reliability concerns. An improved DC link voltage control algorithm, based on the small signal approach, is proposed in this paper, in order to ensure constant input power on the three-phase side despite the pulsating single-phase output power. This algorithm theoretically eliminates the twice ripple effect on 3ϕ quantities, optimising harmonic content and system performance. Simulation results validate the effectiveness of the method, with experimental validation planned for a same scale power conversion system. These results will be detailed in an extended version of this paper. Compared to conventional solutions, this approach significantly improves three-phase side ripple mitigation, increasing the performance and reliability of the power conversion system without the need for additional equipment.

关键词： Electric potential Voltage measurement System performance Simulation Frequency conversion Harmonic analysis Power conversion Voltage control Power generation Frequency control

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