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Autonomous multi-drone racing method based on deep reinforcement learning

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Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： Yu KANG Jian DI Ming LI yunbo zhao Yuhui WANG Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： autonomous multi-drone racing deep reinforcement learning Markov game racing drone sim-to-real

银杏硫酸盐木质素组分分离及其抗肿瘤构效研究

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林产化学与工业 2024年第1期44卷 17-23页

作者：谢益民岳园园赵云博魏鑫湖北工业大学制浆造纸研究院湖北武汉430068 湖北工业大学绿色轻工材料湖北省重点实验室湖北武汉430068

为了从硫酸盐木质素中提取具有抗肿瘤活性的成分,以不同极性的溶剂对银杏硫酸盐木质素(KL)进行分级,利用MTT法研究各分级组分的抗肿瘤活性;根据抗肿瘤活性结果,利用中压制备液相色谱对抑制效果最明显组分进行纯化,采用质谱、^(13)C NMR... 详细信息

为了从硫酸盐木质素中提取具有抗肿瘤活性的成分,以不同极性的溶剂对银杏硫酸盐木质素(KL)进行分级,利用MTT法研究各分级组分的抗肿瘤活性;根据抗肿瘤活性结果,利用中压制备液相色谱对抑制效果最明显组分进行纯化,采用质谱、^(13)C NMR等方法确定其结构,并分析构效关系。FT-IR分析结果表明:KL具有与银杏磨木木质素(MWL)相似的结构;分级组分的总酚含量(TPC)随着其相对分子质量增加而降低。抗肿瘤实验结果表明:乙醚可溶组分(LC2)对人源肺癌A549细胞的抑制作用最强,IC_(50)值为(366.09±6.39) mg/L。LC2纯化结果发现,分离出的化合物L7的抗肿瘤活性最好,对肺癌A549细胞的IC_(50)值为(89.44±2.13) mg/L。质谱、^(13)C NMR测试结果表明:化合物L7是酚羟基上连接着2-丙醛取代基的β-5结构的松柏醛二聚体。木质素小分子物质的苯丙烷单元侧链上醛基的增加会提高抗癌活性,但是醚键的增加会降低抗癌活性。

关键词：硫酸盐木质素分级组分生理活性化合物抗肿瘤活性化学结构

肌少症与老年局部进展期结直肠癌患者长期预后的相关性分析

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中华老年医学杂志 2024年第7期43卷 851-856页

作者：胡雪晴赵赟博聂鑫施红李琳北京医院肿瘤内科、国家老年医学中心、中国医学科学院老年医学研究院北京100730 北京医院老年医学科、国家老年医学中心、中国医学科学院老年医学研究院北京100730

目的探讨肌少症与老年局部进展期结直肠癌(LACRC)患者长期预后的相关性。方法回顾性分析2014年1月至2018年12月北京医院接受根治性切除术、TNM分期为Ⅱ~Ⅲ期的205例70岁及以上老年LACRC患者的临床资料,应用术前30 d内的腹部CT测量第3腰... 详细信息

目的探讨肌少症与老年局部进展期结直肠癌(LACRC)患者长期预后的相关性。方法回顾性分析2014年1月至2018年12月北京医院接受根治性切除术、TNM分期为Ⅱ~Ⅲ期的205例70岁及以上老年LACRC患者的临床资料,应用术前30 d内的腹部CT测量第3腰椎截面的骨骼肌面积(SMA),肌少症的定义为骨骼肌指数(SMI)(SMI=SMA/身高^(2))男性≤52.4 cm^(2)/m^(2)、女性≤38.5 cm^(2)/m^(2),比较肌少症和非肌少症两组患者的临床和病理情况,分析肌少症对老年LACRC术后患者长期预后的影响。结果205例患者中,63.4%(130/205)患者患有肌少症。与非肌少症患者比较,肌少症组患者中80岁及以上高龄老年人比例更高(χ^(2)=6.420、P=0.011)、超重或肥胖的比例更低(χ^(2)=9.366、P=0.009)、接受辅助化疗比例和术后5年无疾病生存率更低(χ^(2)=6.257、7.347,P=0.012、0.007)。Kaplan-Meier分析结果显示,非肌少症组的老年LACRC患者无疾病生存(DFS)率优于肌少症组患者(Log-rankχ^(2)=6.919、P=0.009);非肌少症组老年LACRC患者中,辅助化疗组DFS率优于非辅助化疗组(Log-rankχ^(2)=4.745、P=0.029)。多因素Cox回归分析结果显示,TNM分期为Ⅲ期(HR=1.634,95%CI:1.110~2.404,P=0.013)和患肌少症(HR=1.509,95%CI:1.017~2.238,P=0.041)是老年LACRC患者长期预后不良的影响因素。结论肌少症和老龄及体质指数相关,患有肌少症的老年LACRC患者长期预后欠佳,非肌少症的老年LACRC患者可能获益于辅助化疗。

关键词：结直肠肿瘤预后肌少症

Robust Nonsingular Fixed Time Terminal Sliding Mode Control for Atmospheric Pollution Detection Lidar Scanning Mechanism

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Journal of Systems Science & Complexity 2023年第2期36卷 500-523页

作者： KANG Yu YANG Yuxiao CHEN Cai LüWenjun zhao yunbo Department of Automation University of Science and Technology of ChinaHefei 230027China Institute of Advanced Technology University of Science and Technology of ChinaHefei 230027China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230027China

A robust nonsingular fixed time terminal sliding mode control scheme with a time delay disturbance observer is proposed for atmospheric pollution detection lidar scanning mechanism(APDL-SM)*** from the conventional terminal sliding mode control methods,the authors design a novel fixed-time terminal sliding surface,the convergence time of sliding mode phase of which has a constant upper bound that is designable by adjusting only one ***,in order to overcome the problem of unknown upper bound of lumped uncertainty including model uncertainty,friction effect and external disturbances from the port environment,the authors propose a time delay disturbance observer to provide an estimation for the system lumped *** using the Lyapunov synthesis,the explicit analysis of the convergence time upper bound are ***,simulation studies are conducted on the APDL-SM system to show the fast convergence rate and strong robustness of the proposed control scheme.

关键词： Atmospheric pollution detection lidar fixed time terminal sliding mode time delay disturbance observer tracking control

The Dynamics Characteristics of Flexible Spacecraft and Its Closed-Loop Stability with Passive Control

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Journal of Systems Science & Complexity 2021年第3期34卷 860-872页

作者： MENG Bin zhao yunbo Beijing Institute of Control Engineering Beijing 100094China Science and Technology on Space Intelligent Control Laboratory Beijing 100094China Zhejiang University of Technology Hangzhou 310014China

Passive control is the most popular methodology for flexible spacecraft while it remains an open problem whether the closed-loop performance can be achieved only with passive control subject to the coupling modes of rigid and ***,the closed-loop performance of passive PD control based on the dynamics of the Euler angle parameterization of spacecraft,which has been widely used in practice,is yet to be *** these challenges,by introducing the input-output exact linearization theory and Lyapunov theory,the authors show that the closed-loop performance for flexible spacecraft with rigid and flexible modes can be achieved by adjusting the parameters of the passive controllers sufficiently *** is done by firstly transforming the flexible spacecraft dynamics into an exact feedback linearization standard form,and then analyzing the closed-loop performance of flexible spacecraft.

关键词： Closed-loop stability flexible spacecraft internal dynamics input-output exact linearization passive control

Dynamic data packing towards the optimization of QoC and QoS in networked control systems

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Science China(Technological Sciences) 2016年第1期59卷 72-80页

作者： KANG Yu zhao yunbo Department of Automation and State Key Laboratory of Fire Science University of Science and Technology of China Key Laboratory of Technology in Geo-Spatial Information Processing and Application System Chinese Academy of Sciences Department of Automation Zhejiang University of Technology

A class of networked control systems is investigated whose communication network is shared with other applications. The design objective for such a system setting is not only the optimization of the control performance but also the efficient utilization of the communication resources. We observe that at a large time scale the data packet delay in the communication network is roughly varying piecewise constant, which is typically true for data networks like the Internet. Based on this observation, a dynamic data packing scheme is proposed within the recently developed packet-based control framework for networked control systems. As expected this proposed approach achieves a fine balance between the control performance and the communication utilization: the similar control performance can be obtained at dramatically reduced cost of the communication resources. Simulations illustrate the effectiveness of the proposed approach.

关键词：网络控制系统数据包服务质量控制质量优化网络化控制系统应用程序共享通信网络

Bipartite Consensus of Discrete-Time Double-Integrator Multi-Agent Systems with Measurement Noise

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Journal of Systems Science & Complexity 2018年第6期31卷 1525-1540页

作者： MA Cuiqin zhao Weiwei zhao yunbo School of Mathematical Sciences Qufu Normal UniversityQufu 273165China. No.1Senior Middle School of Qufu Qufu 273165China College of Information Engineering Zhejiang University of TechnologyHangzhou 310023China

The effects of measurement noise are investigated in the context of bipartite consensus of multi-agent systems. In the system setting, discrete-time double-integrator dynamics are assumed for the agent, and measurement noise is present for the agent receiving the state information from its neighbors. Time-varying stochastic bipartite consensus protocols are designed in order to lessen the harmful effects of the noise. Consequently, the state transition matrix of the closed-loop system is analyzed, and sufficient and necessary conditions for the proposed protocol to be a mean square bipartite consensus protocol are given with the help of linear transformation and algebraic graph theory. It is proven that the signed digraph to be structurally balanced and having a spanning tree are the weakest communication assumptions for ensuring bipartite consensus. In particular, the proposed protocol is a mean square bipartite average consensus one if the signed digraph is also weight balanced.

关键词： Bipartite consensus discrete-time double-integrator measurement noise multi-agent systems

Predictive Event-Triggered Control for Disturbanced Wireless Networked Control Systems

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Journal of Systems Science & Complexity 2021年第3期34卷 1028-1043页

作者： zhao yunbo PAN Xiaokang YU Shiming College of Information Engineering Zhejiang University of TechnologyHangzhou 310023China

The control and scheduling for wireless networked control system with packet dropout and disturbance are investigated.A prediction based event triggered control is proposed to reduce data transmissions while preserving the robustness against external ***,a trigger threshold is especially designed to maintain the difference of the estimated and actual states below a proper boundary when system suffers from packet *** a predictive controller is designed to compensate for packet dropouts by utilizing the packet-based control *** sufficient conditions to ensure the closed-loop system being uniformly ultimately bounded are derived,with consequently the controller gain *** examples illustrate the effectiveness of the proposed approach.

关键词： Event-trigger packet-based control wireless networked control systems

Self-Tuning Asynchronous Filter for Linear Gaussian System and Applications

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IEEE/CAA Journal of Automatica Sinica 2018年第6期5卷 1054-1061页

作者： Wenjun Lv Yu Kang yunbo zhao Department of Automation University of Science and Technology of ChinaHefei 230027China State Key Laboratory of Fire Science Department of Automation and Institute of Advanced TechnologyUniversity of Science and Technology of ChinaHefei 230027China Key Laboratory of Technology in GeoSpatial Information Processing and Application System Chinese Academy of SciencesBeijing 100190China College of Information Engineering Zhejiang University of TechnologyHangzhou 310023China

In this paper, optimal filtering problem for a class of linear Gaussian systems is studied. The system states are updated at a fast uniform sampling rate and the measurements are sampled at a slow uniform sampling rate. The updating rate of system states is several times the sampling rate of measurements and the multiple is constant. To solve the problem,we will propose a self-tuning asynchronous filter whose contributions are twofold. First, the optimal filter at the sampling times when the measurements are available is derived in the linear minimum variance sense. Furthermore, considering the variation of noise statistics, a regulator is introduced to adjust the filtering coefficients adaptively. The case studies of wheeled robot navigation system and air quality evaluation system will show the effectiveness and practicability in engineering.

关键词：最优滤波噪声统计量机器人自动化系统