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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1190-1201页

作者： Xiangqian Yao Hao Sun zhijia zhao Yu Liu School of Automation Science and Engineering South China University of TechnologyGuangzhou 510640China Yongjiang Laboratory Ningbo 315202 School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China

For bipartite angle consensus tracking and vibration suppression of multiple Timoshenko manipulator systems with time-varying actuator faults,parameter and modeling uncertainties,and unknown disturbances,a novel distributed boundary event-triggered control strategy is proposed in this *** contrast to the earlier findings,time-varying consensus tracking and actuator defects are taken into account *** addition,the constructed event-triggered control mechanism can achieve a more flexible design because it is not required to satisfy the input-to-state *** achieve the control objectives,some new integral control variables are given by using back-stepping technique and boundary ***,adaptive neural networks are applied to estimate system *** the proposed event-triggered scheme,control inputs can reduce unnecessary ***,tracking errors and vibration states of the closed-looped network can be exponentially convergent into some small fields,and Zeno behaviors can be *** last,some simulation examples are given to state the effectiveness of the control algorithms.

关键词： Vibration satisfy bipartite

Adaptive neural network control of a 2-DOF helicopter system considering input constraints and global prescribed performance

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Science China(Information Sciences) 2024年第7期67卷 224-239页

作者： zhijia zhao Jiale WU Zhijie LIU We HE C.L.Philip CHEN School of Mechanical and Electrical Engineering Guangzhou University School of Intelligence Science and Technology and Key Laboratory of Intelligent Bionic Unmanned Systems of Ministry of Education University of Science and Technology Beijing School of Computer Science and Engineering South China University of Technology Pazhou Lab

In this study, an adaptive neural network(NN) control is proposed for nonlinear two-degree-offreedom(2-DOF) helicopter systems considering the input constraints and global prescribed ***, radial basis function NN(RBFNN) is employed to estimate the unknown dynamics of the helicopter system. Second, a smooth nonaffine function is exploited to approximate and address nonlinear constraint functions. Subsequently, a new prescribed function is proposed, and an original constrained error is transformed into an equivalent unconstrained error using the error transformation and barrier function transformation methods. The analysis of the established Lyapunov function proves that the controlled system is globally uniformly bounded. Finally, the simulation and experimental results on a constructed Quanser's test platform verify the rationality and feasibility of the proposed control.

关键词： adaptive NN control 2-DOF helicopter global prescribed performance input constraints

Finite-Time Convergence Disturbance Rejection Control for a Flexible Timoshenko Manipulator

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IEEE/CAA Journal of Automatica Sinica 2021年第1期8卷 157-168页

作者： zhijia zhao Zhijie Liu the School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China the School of Automation and Electrical Engineering University of Science and Technology Beijing(USTB)Beijing 100083 Shunde Graduate School of USTB Foshan 528300China

This paper focuses on a new finite-time convergence disturbance rejection control scheme design for a flexible Timoshenko manipulator subject to extraneous *** suppress the shear deformation and elastic oscillation,position the manipulator in a desired angle,and ensure the finitetime convergence of disturbances,we develop three disturbance observers(DOs)and boundary *** the derived DOs-based control schemes,the controlled system is guaranteed to be uniformly bounded stable and disturbance estimation errors converge to zero in a finite *** the end,numerical simulations are established by finite difference methods to demonstrate the effectiveness of the devised scheme by selecting appropriate parameters.

关键词： Disturbance observer disturbance rejection control finite-time convergence Timoshenko manipulator vibration control

基于多注意力的改进YOLOv5s小目标检测算法

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工程科学学报 2024年第9期46卷 1647-1658页

作者：马鸽李洪伟严梓维刘志杰赵志甲广州大学机械与电气工程学院广州510006 广州市公用事业技师学院广州510199 北京科技大学智能科学与技术学院北京100083

交通标志识别应用中待检测目标多为小目标,因其携带信息少、定位精度要求高、易被环境噪声淹没等特点成为当前交通标志检测的难点.针对小目标交通标志漏检、误检、检测准确率低等问题,本文设计了一种用于小目标检测的STDYOLOv5s(Small t... 详细信息

交通标志识别应用中待检测目标多为小目标,因其携带信息少、定位精度要求高、易被环境噪声淹没等特点成为当前交通标志检测的难点.针对小目标交通标志漏检、误检、检测准确率低等问题,本文设计了一种用于小目标检测的STDYOLOv5s(Small target detection YOLOv5s)模型.首先,通过增加上采样和Prediction输出层数获得了更丰富的位置信息,解决了YOLOv5s模型在处理小目标时信息不足的问题,增强了对图像的全局理解能力;其次,在每个C3模块之后添加CA(Coordinate attention)注意力机制并在每个输出层前添加Swin-T注意力机制模块,增加了网络对多层特征信息的捕捉,提高了小目标的检测性能;最后,充分利用SIoU惩罚函数同时考虑目标形状、空间关系的特点,更好地捕捉不同尺寸的目标在图像中的位置关系,提高目标位置的精确性.所提模型在TT100K数据集上进行了验证实验,实验结果表明本文方法不仅保持了YOLOv5s模型的轻量性和快速性,在精确率、召回率和平均精度三个指标上也有所提升,提高了小目标检测的精确性.

关键词：小目标检测交通标志识别注意力机制 YOLOv5s 深度学习

Modeling and adaptive control for a spatial flexible spacecraft with unknown actuator failures

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Science China(Information Sciences) 2021年第5期64卷 177-192页

作者： Zhijie LIU Zhiji HAN zhijia zhao Wei HE Key Laboratory of Knowledge Automation for Industrial Processes of Ministry of Education School of Automation and Electrical Engineering Institute of Artificial IntelligenceUniversity of Science and Technology Beijing School of Mechanical and Electrical Engineering Guangzhou University Shunde Graduate School of University of Science and Technology Beijing

In this paper, we address simultaneous control of a flexible spacecraft’s attitude and vibrations in a three-dimensional space under input disturbances and unknown actuator failures. Using Hamilton’s principle, the system dynamics is modeled as an infinite dimensional system captured using partial differential equations. Moreover, a novel adaptive fault tolerant control strategy is developed to suppress the vibrations of the flexible panel in the course of the attitude stabilization. To determine whether the system energies,angular velocities and transverse deflections, remain bounded and asymptotically decay to zero in the case wherein the number of actuator failures is infinite, a Lyapunov-based stability analysis is conducted. Finally,extensive numerical simulations are performed to demonstrate the performance of the proposed adaptive control strategy.

关键词： adaptive control actuator failures infinite-dimensional systems flexible spacecraft fault tolerant control

Autonomous Control Strategy of a Swarm System Under Attack Based on Projected View and Light Transmittance

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IEEE/CAA Journal of Automatica Sinica 2021年第3期8卷 648-655页

作者： Xuejing Lan Wenbiao Xu zhijia zhao Guiyun Liu School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China Guangdong Province Institute of Metrology Guangzhou 510405China

In the study of a visual projection field with swarm movements,an autonomous control strategy is presented in this paper for a swarm system under *** ensure a fast swarm dynamic response and stable spatial cohesion in a complex environment,a new hybrid swarm motion model is proposed by introducing global visual projection information to a traditional local interaction *** the face of attackers,individuals move towards the largest free space according to the projected view of the environment,rather than directly in the opposite direction of the ***,swarm individuals can certainly regroup without dispersion after the attacker *** the other hand,the light transmittance of each individual is defined based on global visual projection information to represent its spatial freedom and relative position in the ***,an autonomous control strategy with adaptive parameters is proposed according to light transmittance to guide the movement of swarm *** simulation results demonstrate in detail how individuals can avoid attackers safely and reconstruct ordered states of swarm motion.

关键词： Autonomous control light transmittance projected view swarm system

Neural-Network-Based Adaptive Finite-Time Control for a Two-Degree-of-Freedom Helicopter System With an Event-Triggering Mechanism

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IEEE/CAA Journal of Automatica Sinica 2023年第8期10卷 1754-1765页

作者： zhijia zhao Jian Zhang Shouyan Chen Wei He Keum-Shik Hong IEEE the School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China the School of Intelligence Science and Technology the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China the School of Mechanical Engineering Pusan National UniversityBusan 46241South Korea the Institute for Future School of AutomationQingdao UniversityQingdao 266071China

Helicopter systems present numerous benefits over fixed-wing aircraft in several fields of *** control schemes for improving the tracking accuracy of such systems is *** paper proposes a neural-network(NN)-based adaptive finite-time control for a two-degree-of-freedom helicopter *** particular,a radial basis function NN is adopted to solve uncertainty in the helicopter ***,an event-triggering mechanism(ETM)with a switching threshold is proposed to alleviate the communication burden on the *** proposing an adaptive parameter,a bounded estimation,and a smooth function approach,the effect of network measurement errors is effectively compensated for while simultaneously avoiding the Zeno ***,the developed adaptive finite-time control technique based on an NN guarantees finitetime convergence of the tracking error,thus enhancing the control accuracy of the *** addition,the Lyapunov direct method demonstrates that the closed-loop system is semiglobally finite-time ***,simulation and experimental results show the effectiveness of the control strategy.

关键词： Adaptive neural-network control event-triggering mechanism(ETM) finite time two-degree-of-freedom helicopter

Modeling and Adaptive Neural Network Control for a Soft Robotic Arm With Prescribed Motion Constraints

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IEEE/CAA Journal of Automatica Sinica 2023年第2期10卷 501-511页

作者： Yan Yang Jiangtao Han Zhijie Liu zhijia zhao Keum-Shik Hong the School of Intelligence Science and Technology University of Science and Technology BeijingBeijing 10083 the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China IEEE the School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China the School of Mechanical Engineering Pusan National UniversityBusan 46241South Korea

This paper presents a dynamic model and performance constraint control of a line-driven soft robotic *** dynamics model of the soft robotic arm is established by combining the screw theory and the Cosserat *** unmodeled dynamics of the system are considered,and an adaptive neural network controller is designed using the backstepping method and radial basis function neural *** stability of the closed-loop system and the boundedness of the tracking error are verified using Lyapunov *** simulation results show that our approach is a good solution to the motion constraint problem of the line-driven soft robotic arm.

关键词： Adaptive control cosserat theory prescribed motion constraints soft robotic arm

Vibration Control of an Experimental Flexible Manipulator Against Input Saturation

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IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1340-1342页

作者： zhijia zhao Sentao Cai Ge Ma F.Richard Yu the School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006 the Guangdong Laboratory of Artificial Intelligence and Digital Economy(SZ) Shenzhen 518060China the Guangdong Laboratory of Artificial Intelligence and Digital Economy(SZ) College of Computer Science&Software EngineeringShenzhen UniversityShenzhen 518060China

Dear Editor, This letter considers the control problem of an experimental flexible manipulator in position tracking, vibration suppression, and saturation compensation. Based on the backstepping technology and a Nussbaum function, we develop an anti-windup control to restrain the manipulator’s vibration, realize the desire trajectory tracking, and eliminate the saturation.

关键词： restrain eliminate Vibration

山东省临沂市楸树人工林立地类型划分与质量评价

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西北林学院学报 2024年第5期39卷 118-125页

作者：赵智佳单增罗布方洋关追追陈述王军辉何茜张鹏麻文俊中国林业科学研究院林业研究所国家林业局林木培育重点实验室林木遗传育种全国重点实验室北京100091 华南农业大学林学与风景园林学广东广州510642 临沂市森林湿地保护中心山东临沂276000 东北林业大学黑龙江哈尔滨150040 西藏自治区林木科学研究院西藏拉萨850000

使用典型抽样方法在山东临沂的蒙阴、沂水、兰陵等6个县区,选择造林技术和经营措施基本一致的14个样点布设63块楸树人工林临时标准地,调查标准地内立地因子、林分生长因子以及土壤因子,通过主成分分析、聚类分析法分析立地因子对人工林... 详细信息

使用典型抽样方法在山东临沂的蒙阴、沂水、兰陵等6个县区,选择造林技术和经营措施基本一致的14个样点布设63块楸树人工林临时标准地,调查标准地内立地因子、林分生长因子以及土壤因子,通过主成分分析、聚类分析法分析立地因子对人工林生长的影响,进而对楸树人工林进行立地类型划分与立地质量评价。结果表明:1)最合适的导向曲线为幂函数曲线,经χ~2检验证明所编制的立地指数表合格。2)在影响楸树人工林生长的立地因子中,重要性排序为:土壤质地>坡向>坡位>坡度>土层厚度>海拔,其中土壤质地、坡向、坡位是影响临沂市楸树人工林生长的主导因子。3)以土壤质地、坡向、坡位3个主导立地因子将山东省临沂市楸树人工林划分为13个立地类型,3个地位级。现有立地条件下,最适宜楸树人工林生长的立地特征为:分布在阳坡或半阴坡的下坡位,土壤质地为中壤土的地区,占总标准地数量的13.64%。整体上,临沂市楸树人工林的立地质量有待提高,建议Ⅰ、Ⅱ地位级种植中大径材楸树,Ⅲ地位级种植小径材楸树。

关键词：楸树立地类型立地质量临沂

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