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Linear active disturbance rejection control of fighter aircraft based on MADDPG algorithm

International Journal of systems, control and Communications 2025年第2期16卷 152-172页

作者： Lin, Yetong Ji, Yuehui Song, Yu Liu, Junjie Tianjin Key Laboratory for Control Theory and Applications in Complicated Industry Systems School of Electrical Engineering and Automation Tianjin University of Technology Tianjin300384 China

To address nonlinearity, strong coupling, and disturbances in fighter aircraft attitude control, this paper proposes an intelligent control method based on multi-agent deep deterministic policy gradient (MADDPG) and linear active disturbance rejection control (LADRC). A three-channel LADRC controller estimates and compensates for disturbances, uncertainties, and coupling terms in real time. To overcome the dimensionality curse in multi-parameter optimization, an independent DDPG controller is assigned to each channel, ensuring cooperative control via reward sharing and enhancing dynamic response and disturbance rejection. Additionally, long short-term memory (LSTM) and self-attention mechanisms are integrated into the policy and value networks to improve representation and decision-making. A piecewise combined reward function mitigates sparse rewards. Simulations show that, compared to MADQN-based and traditional LADRC methods, the proposed approach achieves superior control performance and significantly reduces manual parameter tuning efforts. Copyright © 2025 Inderscience Enterprises Ltd.

关键词： Disturbance rejection

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Effect of radical scavenger on electrical tree in cross-linked polyethylene with large harmonic superimposed DC voltage

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High Voltage 2023年第4期8卷 739-748页

作者： Lewei Zhu Zhonglei Li Kai Hou Maritime College Tianjin Key Laboratory for Control Theory and Applications in Complicated Industry SystemsTianjin University of TechnologyTianjinChina Key Laboratory of Smart Grid of Ministry of Education School of Electrical and Information EngineeringTianjin UniversityTianjinChina

In this study,three kinds of radical scavenger Chimassorb 944,Tinuvin 622,and Tinuvin 770 are used to suppress the growth of electrical trees in cross-linked polyethylene(XLPE)with transient superimposed voltage under the temperature *** tree morphology,tree length,accumulated damage,and time to breakdown are used to investigate the effect of radical scavenger on the electrical treeing *** is found that under the temperature gradient caused by the temperature rise on the high voltage side,only Tinuvin 622 can always suppress the electrical tree as the temperature gradient *** the temperature gradient caused by the temperature rise on the ground side,the three radical scavengers can all suppress the electrical *** breakdown of electrical tree exhibits the strong DC polarity ***,energy levels of these three radical scavengers are calculated through quantum chemistry,and the results indicate that radical scavengers have greater electron affinity,smaller ionisation energy,and smaller energy gap than *** to the surface potential decay test results at 60℃,it is found that all three radical scavengers can introduce deep *** different performances of radical scavengers under different temperature gradients and voltages are determined by the trap distribution characteristics,the molecular structure and chemical reaction of the additives *** is concluded that Tinuvin 622 has potential for use in high voltage direct current XLPE cable application.

关键词： radical electrical harmonic

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A Method for Allocating Hybrid Teaching Credit Hours Using Hierarchical Analysis 25

A Method for Allocating Hybrid Teaching Credit Hours Using H...

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25th IEEE China Conference on System Simulation Technology and its Application, CCSSTA 2024

作者： Meng, Xiangang Li, Xiaojing Xu, Liang School of Electrical Engineering and Automation Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems Tianjin China

ISBN: (纸本)9798350366600

Hybrid teaching combines traditional teaching and flipped classroom, which is a new teaching mode with the advantages of both modes. In hybrid teaching mode, reasonable allocation of credit hours between traditional teaching and flipped classroom is an important issue for the teaching work. This paper first proposes a method of using hierarchical analysis to allocate credit hours for hybrid teaching of Digital Electronic Technology courses. Firstly, we divided hybrid teaching into stage and content layers, and determined the various elements of stage and content layers. Secondly, the requirements of the Analytic Hierarchy Process were applied to organize these two levels, and pairwise importance comparisons were made for each element within the level. Index judgment matrices were established for the stage level and content level, respectively. Then, the calculation steps of the Analytic Hierarchy Process were designed, and matrix operations were used to obtain the normalized weights of each element in the stage and content layers of traditional teaching and flipped classrooms. This weight was used to determine the class hours to be allocated for each stage and content. Finally, the feasibility and effectiveness of the method proposed in this paper were verified using the example of hybrid teaching hour allocation in Chapter 4 of the Digital Electronic Technology course at tianjin University of Technology. © 2024 IEEE.

关键词： Hierarchical systems

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Predefined time backstepping control of photovoltaic grid connected inverter 6

Predefined time backstepping control of photovoltaic grid co...

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2023 6th International Conference on Power Electronics and control Engineering, ICPECE 2023

作者： Xu, Zhao Ji, Yuehui Chen, Jiaqi Liu, Junjie The School of Electrical Engineering and Automation Tianjin University of Technology Tianjin300384 China Tianjin Key Laboratory for Control Theory and Applications in Complicated Industry Systems Tianjin300384 China

The large-scale grid connection of photovoltaic (PV) systems creates great hazards to the operation of power equipment and has a great impact on the stability and reliability of power systems. To achieve stable control and flexible management of PV grid connection, a predefined time adaptive backstepping control method based on the predefined boundary is proposed. Based on the predefined boundary time-varying function, the user's predefined boundary design of the control signal is accomplished to ensure the boundedness of the global signal, which is independent of the initial state of the system. The controller with predefined boundaries is designed based on backstepping control, and the estimation and compensation of perturbations are attained based on adaptive control. The global predefined time stability of the predefined boundary of the closed-loop system is certified using the Lyapunov function. Simulation studies attest to the performance of the predefined time control strategy. © Published under licence by IOP Publishing Ltd.

关键词： Lyapunov functions

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Fixed-Time prescribed performance fault-Tolerant control for quadrotor UAV based on ESO

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International Journal of systems, control and Communications 2023年第3期14卷 207-235页

作者： Liu, Lei Li, Junfang Ji, Yuehui Liu, Junjie Song, Yu Niu, Wenxing Tianjin Key Laboratory for Control Theory Applications in Complicated Industry Systems School of Electrical Engineering and Automation Tianjin University of Technology Tianjin300384 China Tianjin Enpromi Environmental Protection Technology Co. Ltd. Tianjin300462 China

Considering the need for high precision control in the flight process of quadrotor unmanned aerial vehicle (UAV), a kind of fault-Tolerant control strategy based on fixed-Time prescribed performance control (FXTPPC) and extended state observer (ESO) is designed to solve the control problem of quadrotor UAV in the case of external disturbance, output error constraint and fault. Firstly, a simplified model of quadrotor UAV is established. Secondly, a double closed-loop fixed-Time continuous output feedback controller based on inner loop attitude control and outer loop position control is designed. The actuator fault, sensor fault and external disturbance are estimated and compensated by ESO in real time to effectively solve the quadrotor stability control problem. Further, a FXTPPC function is introduced to convert the original constrained nonlinear system into the equivalent unconstrained nonlinear system. Finally, the stability analysis shows that the designed controller can guarantee the stability of system. Simulation results also verify the effectiveness of the proposed scheme. The tracking error can converge rapidly to the range specified by the performance function within the fixed time. © 2023 Inderscience Enterprises Ltd.

关键词： Attitude control

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Distributed-Observer-Based on Longitudinal Flight control for Hypersonic Vehicle 42

Distributed-Observer-Based on Longitudinal Flight Control fo...

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42nd Chinese control Conference, CCC 2023

作者： Ji, Yuehui Zhao, Yiming Chen, Jiaqi Liu, Junjie Gao, Qiang School of Electrical Engineering and Automation Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems Tianjin300384 China

ISBN: (纸本)9789887581543

An output feedback control is investigated to achieve stable tracking of velocity and altitude in hypersonic flight vehicle in the paper. A distributed observer is proposed to estimate the unmeasurable flight path angel and angle of attack through a strongly connected directed network topology. Then, a nonlinear control is addressed on the longitudinal dynamics of a rigid hypersonic flight vehicle (HFV) with partial measurable states and the estimated states. The system dynamic is divided into the altitude subsystem and the velocity subsystem. In the altitude subsystem, the backstepping design is proposed for constructing the controllers utilizing the estimated states. The nonlinear dynamic inversion controller is introduced to accomplish the velocity tracking. Finally, numerical simulations verify the effectiveness of the proposed control scheme in providing favorable tracking performance and exact state estimation ability. © 2023 Technical Committee on control theory, Chinese Association of Automation.

关键词： Hypersonic vehicles

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Aero-optic imaging deviation prediction based on ISSA-ELM

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Optoelectronics Letters 2023年第7期19卷 425-431页

作者： XU Liang ZHAO Shiwei WANG Tao Tianjin Key Laboratory for Control Theory&Applications in Complicated Systems School of Electrical Engineering and AutomationTianjin University of TechnologyTianjin 300384China School of Intelligent Engineering Sun Yat-sen UniversityGuangzhou 510275China

When the aircraft is moving at high speed in the atmosphere,aero-optical imaging deviation will appear due to the influence of aero-optical *** order to achieve real-time compensation during the flight of the aircraft,it is necessary to analyze and predict the obtained imaging deviation *** order to improve the search speed and accuracy of the prediction algorithm and the ability to jump out of local optimum,in this paper,an improved sparrow search algorithm optimized extreme learning machine(ISSA-ELM) neural network model is proposed to predict the aero-optical imagine ***,the performance of ISSA-ELM,ELM neural network and SSA-ELM neural network was *** results showed that compared with ELM and SSA-ELM algorithms,the convergence speed of ISSA-ELM was significantly enhanced,and the accuracy of data prediction was also significantly improved.

关键词： effect. deviation extreme

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Named Entity Recognition in Chinese Medical Texts Based on RoBERTa-WWM-IDCNN-CRF 25

Named Entity Recognition in Chinese Medical Texts Based on R...

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25th IEEE China Conference on System Simulation Technology and its Application, CCSSTA 2024

作者： Tang, Lan Kong, Jie Xu, Liang Xi'an Shiyou University School of Computer Xi'an China Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems School of Electrical Engineering and Automation Tianjin China

ISBN: (纸本)9798350366600

Electronic medical records and doctor-patient conversations contain a wealth of useful information, such as disease symptoms, drug names, and cure cycles. Traditional deep learning approaches utilize bidirectional recurrent neural networks to encode text, which cannot effectively capture long-distance dependencies in text. In order to identify medical entity types in various texts more accurately, a named entity recognition approach based on RoBERTa-WWM-IDCNN-CRF is proposed. This approach introduces the RoBERTa-WWM pre-trained model, in order to improve the overall understanding of long Chinese texts for the first time. The model generates semantic representations containing prior knowledge. Then, the generated semantic representations are feed to the IDCNN to extract sentence level characteristics. Finally, the global optimal solution is obtained and the results of the named entity are produced through the CRF. The experiment indicates that the improvement of F1 score, accuracy, and recall of RoBERTa-WWM-IDCNN-CRF model are 7.94%, 4.52% and 10.02% comparing with the classical BiLSTM-CRF model. © 2024 IEEE.

关键词： Convolutional neural networks

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Output Regulation for Multi-Quadrotor by Event-Triggered Mechanism

Output Regulation for Multi-Quadrotor by Event-Triggered Mec...

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International Conference on Guidance, Navigation and control, ICGNC 2020

作者： Che, Shixing Gao, Qiang Ji, Yuehui Tianjin Key Laboratory for Control Theory and Applications in Complicated Systems Tianjin University of Technology Tianjin China

ISBN: (纸本)9789811581540

To accomplish the stable tracking of the multi-quadrotor, an attitude controller based on output regulation and event triggered control (ETC) is proposed to save communication and computing resources effectively. Aiming at the problems of asymptotically tracking and rejecting disturbances, a dynamic compensator, i.e., a novel internal model is designed to convert the output regulation problem of the multi-quadrotor system into the robust stabilization problem of augmented system. The designed internal model studies the desired state and desired input for each quadrotor which depends on the sampled signal of the adjacent quadrotor and itself. To this end, a novel distributed event triggered mechanism (DETM) that exclude Zeno phenomenon and a novel distributed event triggered control law (DETCL) are adopted. The stability and boundedness of all signals in the multi-quadrotor system are proved by Lyapunov method. At last, numerical simulation verify the availab.lity of the controller in providing satisfactory tracking response and saving control energy. © 2022, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Attitude control

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Research on Sign Language Gesture Division and Gesture Extraction in Complex Background

Research on Sign Language Gesture Division and Gesture Extra...

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2022 International Conference on Computer Vision, Application, and Algorithm, CVAA 2022

作者： Tian, Yifan Han, Fangfang Zhu, Minfeng Xu, Xiaoliang Li, Yadong School of Electrical Engineering and Automation China Tianjin University of Technology Tianjin300384 China Tianjin Key Laboratory for Control Theory and Applications in Complicated Systems China

ISBN: (纸本)9781510664036

Sign language plays an important role in information transmission and emotional communication between deaf-mute people and the outside world. With the development of artificial intelligence technology, the recognition, translation and generation of sign language based on digital image processing have attracted worldwide attention. In the field of sign language recognition, effective hand division and gesture extraction are the first and key steps, which directly affect the accuracy of sign language recognition. In this paper, a hand information extraction method based on depth image processing is proposed to solve the problem of sign language gesture extraction in complex background. For sign language speakers,hands are at the front of their bodies, so the depth images of sign language speakers can be collected by depth camera, and the complex background can be removed and hand information can be extracted by segmenting different color objects in the depth images. In this paper, the D435i camera of Inter is used to capture the depth image of the sign language speaker, and the HSV color space model based on the digital image is used for threshold processing of the fusion of hue components and brightness components to achieve the division of the hand position;through median filtering and mathematical morphology of digital image, division noise is removed and interference is reduced. Through skeleton extraction algorithm, the gesture gesture can be obtained. Experiments show that the proposed acquisition scheme and algorithm flow in this paper can effectively realize hand position division and gesture extraction in complex background conditions, and provide a good foundation for subsequent gesture recognition and expression. © 2023 SPIE.

关键词： Morphology

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