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Towards resilient average consensus in multi-agent systems:a detection and compensation approach

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Frontiers of Information technology & Electronic Engineering 2024年第2期25卷 182-196页

作者： Chongrong FANG Wenzhe ZHENG Zhiyu HE Jianping HE Chengcheng ZHAO Jingpei WANG Department of Automation Shanghai Jiao Tong UniversityShanghai200240China State key laboratory of Industrial control technology Zhejiang UniversityHangzhou310027China technology and Engineering Center for space Utilization Chinese Academy of SciencesBeijing100094China

Consensus is one of the fundamental distributed control technologies for collaboration in multi-agent systems such as collaborative handling in intelligent *** this paper,we study the problem of resilient average consensus for multi-agent systems with misbehaving *** protect consensus value from being influenced by misbehaving nodes,we address this problem by detecting misbehaviors,mitigating the corresponding adverse impact,and achieving the resilient average *** types of misbehaviors are considered,including attacks,accidental faults,and link *** characterize the adverse impact of misbehaving nodes in a distributed manner via two-hop communication information and develop a deterministic detection compensation based consensus(D-DCC)algorithm with a decaying fault-tolerant error *** scenarios wherein information sets are intermittently available due to link failures,a stochastic extension named stochastic detection compensation based consensus(S-DCC)algorithm is *** prove that D-DCC and S-DCC allow nodes to asymptotically achieve resilient accurate average consensus and unbiased resilient average consensus in a statistical sense,***,the Wasserstein distance is introduced to analyze the accuracy of ***,extensive simulations are conducted to verify the effectiveness of the proposed algorithms.

关键词： Resilient consensus Multi-agent systems Malicious attacks Detection Compensation

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Detachment Behavior of Gecko Toe in Functional Strategies for Bionic Toe

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Journal of Bionic Engineering 2024年第2期21卷 707-717页

作者： Qingfei Han Wei Wang Huan Shen Xincheng Feng Haoran Zhang Qian Li Yi Sun Huapeng Wu Aihong Ji Lab of Locomotion Bioinspiration and intelligent Robots College of Mechanical and Electrical EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China laboratory of intelligent Machines School of Energy SystemsLappeenranta-Lahti University of Technology53850LappeenrantaFinland State key laboratory of Mechanics and control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

Geckos can efficiently navigate complex terrains due to their multi-level adhesive system that is present on their *** setae are responsible for the gecko’s extraordinary adhesion and have garnered wide attention from the scientific *** majority of the reported works in the literature that have dealt with the peeling models mainly focus on the gecko hierarchical adhesive system,with limited attention given to investigating the influence of gecko toe structure on the *** these lines,to gain a deeper understanding of the rapid and effortless detachment abilities of gecko toes,the peeling behavior of gecko toes on vertical surfaces was primarily investigated in this *** specifically,the detachment time of a single toe on a smooth acrylic plate was measured to be 0.41±0.21 ***,it was observed that the toe assumed a"U"-shaped structure upon complete ***,Finite Element Analysis(FEA)models for three different types of gecko toes were developed to simulate both the displacement-peel and the moment-peel *** the segmentation of the adhesive layer led to a gradual decrease in the resultant force,as well as the normal and tangential ***,a gecko-inspired toe model was constructed and powered by Shape Memory Alloy(SMA).A systematic comparison between the vertical drag separation and the outward flip separation was also *** our analysis,it was clearly demonstrated that outward peel separation significantly necessitated the reduction of the peeling force,thus confirming the advantageous nature of the outward motion in gecko toe *** data not only contribute to a deeper understanding of the gecko detachment behavior but also offer valuable insights for the advancement of the wall-climbing robot feet.

关键词： Gecko toes Detachment behavior Finite element analysis Gecko-inspired toe

Physics-informed deep Koopman operator for Lagrangian dynamic systems

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science China(Information sciences) 2024年第9期67卷 146-163页

作者： Xuefeng WANG Yang CAO Shaofeng CHEN Yu KANG Department of Automation University of Science and Technology of China State key laboratory of Fire science University of Science and Technology of China Institute of Advanced technology University of Science and Technology of China

Accurate mechanical system models are crucial for safe and stable control. Unlike linear systems,Lagrangian systems are highly nonlinear and difficult to optimize because of their unknown system *** research thus used deep neural networks to generate linear models of original systems by mapping nonlinear dynamic systems into a linear space with a Koopman observable function encoder. The controller then relies on the Koopman linear model. However, without physical information constraints, ensuring control consistency between the original nonlinear system and the Koopman system is tough, as the learning process of the Koopman observation function is unsupervised. This paper thus proposes a two-stage learning algorithm that uses structural subnetworks to build a physics-informed network topology to simultaneously learn the Koopman observable functions and the system energy representation. In the Koopman matrix learning session, a quadratic-constrained optimization problem is solved to ensure that the Koopman representation satisfies the energy difference matching hard constraint. The proposed energy-preserving deep Lagrangian Koopman(EPDLK) framework effectively represents the dynamics of the Lagrangian system while ensuring control consistency. The effectiveness of EPDLK is compared with those of various Koopman observable function construction methods in multistep prediction and trajectory tracking tasks. EPDLK achieves better control consistency by guaranteeing energy difference matching, which facilitates the application of the control law generated on the Koopman system directly to the original nonlinear Lagrangian system.

关键词： Koopman operator Lagrangian physics-informed nonlinear model predictive control (MPC)

Graphene binding on black phosphorus enables high on/off ratios and mobility

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National science Review 2024年第2期11卷 188-195页

作者： Fanrong Lin Zhonghan Cao Feiping Xiao Jiawei Liu Jiabin Qiao Minmin Xue Zhili Hu Ying Liu Huan Lu Zhuhua Zhang Jens Martin Qingjun Tong Wanlin Guo Yanpeng Liu key laboratory for intelligent Nano Materials and Devices of Ministry of Education State Key Laboratory of Mechanics and Control of Mechanical Structures and Institute for Frontier Science Nanjing University of Aeronautics and Astronautics Centre for Advanced 2D Materials National University of Singapore School of Physics and Electronics Hunan University Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and MeasurementSchool of PhysicsBeijing Institute of Technology Leibniz Institute für Kristallzüchtung

Graphene is one of the most promising candidates for integrated circuits due to its robustness against short-channel effects, inherent high carrier mobility and desired gapless nature for Ohmic contact, but it is difficult to achieve satisfactory on/off ratios even at the expense of its carrier mobility, limiting its device applications. Here, we present a strategy to realize high back-gate switching ratios in a graphene monolayer with well-maintained high mobility by forming a vertical heterostructure with a black phosphorus multi-layer. By local current annealing, strain is introduced within an established area of the graphene, which forms a reflective interface with the rest of the strain-free area and thus generates a robust off-state via local current depletion. Applying a positive back-gate voltage to the heterostructure can keep the black phosphorus insulating, while a negative back-gate voltage changes the black phosphorus to be conductive because of hole accumulation. Then, a parallel channel is activated within the strain-free graphene area by edge-contacted electrodes, thereby largely inheriting the intrinsic carrier mobility of graphene in the on-state. As a result, the device can provide an on/off voltage ratio of >10～3 as well as a mobility of ～8000 cm2V-1s-1at room temperature, meeting the low-power criterion suggested by the International Roadmap for Devices and Systems.

关键词： graphene on/off ratio mobility black phosphorus reflective interface

A Bio-inspired Mutual-hook Strategy for the Soft Finger to Improve Load-bearing Capacity and Grasping Stability

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Journal of Bionic Engineering 2024年第3期21卷 1290-1304页

作者： Jie Huang Lingjie Gai Xiaofeng Zong Yunquan Li School of Automation China University of GeosciencesWuhan430074China Hubei key laboratory of Advanced control and intelligent Automation for Complex System Wuhan430074China The Shien-Ming Wu School of intelligent Engineering South China University of TechnologyGuangzhou510641China

Soft grippers have great potential applications in daily life,since they can compliantly grasp soft and delicate ***,the highly elastic fingers of most soft grippers are prone to separate from each other while grasping objects due to their low stiffness,thus reducing the grasping stability and load-bearing *** tackle this problem,inspired from the venus flytrap plant,this work proposes a mutual-hook mechanism to restrain the separation and improve the grasping performance of soft *** novel soft gripper design consists of three modules,a soft finger-cot,two Soft Hook Actuators(SHAs)and two sliding ***,the soft finger-cot covers on the soft finger,increasing the contact area with the target object,two SHAs are fixed to the left and right sides of the finger-cot,and the sliding mechanisms are designed to make SHAs stretch *** demonstrate that the proposed design can restrain the separation of soft fingers substantially,and the soft fingers with the finger-cots can grasp objects three times heavier than the soft fingers without the proposed *** proposed design can provide invaluable insights for soft fingers to restrain the separation while grasping,thus improving the grasping stability and the load-bearing capacity.

关键词： Soft robotics Soft bionic finger-cot Soft hook actuator Grasping stability Load-bearing capacity

Roughness characterization and shearing dislocation failure for rock-backfill interface

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1167-1176页

作者： Meifeng Cai Zhilou Feng Qifeng Guo Xiong Yin Minghui Ma Xun Xi key laboratory of High-Efficient Mine and Safety of Metal Mines of Ministry of Education Beijing 100083China key laboratory of Urban and Underground space Engineering University of Science and Technology BeijingBeijing 100083China Shandong Gold Group Co LtdJinan 250102China

Shearing dislocation is a common failure type for rock–backfill interfaces because of backfill sedimentation and rock strata movement in backfill mining *** paper designed a test method for rock–backfill shearing *** digital image techno-logy and three-dimensional(3D)laser morphology scanning techniques,a set of 3D models with rough joint surfaces was ***,the mechanical behavior of rock–backfill shearing dislocation was investigated using a direct shear *** effects of interface roughness on the shear–displacement curve and failure characteristics of rock–backfill specimens were *** 3D fractal dimen-sion,profile line joint roughness coefficient(JRC),profile line two-dimensional fractal dimension,and the surface curvature of the frac-tures were *** correlation characterization of surface roughness was then analyzed,and the shear strength could be measured and calculated using *** results showed the following:there were three failure threshold value points in rock–backfill shearing dis-location:30%–50%displacement before the peak,70%–90%displacement before the peak,and 100%displacement before the peak to post-peak,which could be a sign for rock–backfill shearing dislocation *** surface JRC could be used to judge the rock–backfill shearing dislocation failure,including post-peak sliding,uniform variations,and gradient change,corresponding to rock–backfill disloca-tion failure on the field *** research reveals the damage mechanism for rock–backfill complexes based on the free joint surface,fills the gap of existing shearing theoretical systems for isomerism complexes,and provides a theoretical basis for the prevention and control of possible disasters in backfill mining.

关键词： rock–backfill roughness correlation characterization shearing dislocation interface failure

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Observer design and interval estimation of time-delay discrete-time linear systems with external disturbance and measurement noise

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control Theory and technology 2024年第1期22卷 69-80页

作者： Junqi Yang Jianhao Xie Feiyang Liu School of Electrical Engineering and Automation Henan Key Laboratory of Intelligent Detection and Control of Coal Mine EquipmentHenan Polytechnic UniversityJiaozuo454003HenanChina

For a class of time-delay discrete-time linear systems with external disturbance and measurement noise, the interval estimation problems of state and measurement noise are investigated in this paper. First, the system state together with the time-delay term and measurement noise is augmented as a new state, and a singular system is then constructed. Subsequently, a kind of decoupling technique is employed to eliminate the effect of external disturbance, and an observer is designed to simultaneously estimate the system state and measurement noise. Based on the estimated state and measurement noise, the interval estimations of system state and measurement noise are obtained by reachability analysis technique. Finally, the effectiveness of the proposed method is verified by a four-tank liquid level system.

关键词： Interval estimation Time-delay system Observer design Reachability analysis

Finite-time tracking control of heterogeneous multi-AUV systems with partial measurements and intermittent communication

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science China(Information sciences) 2024年第5期67卷 165-182页

作者： Bo CHEN Jiangping HU Bijoy Kumar GHOSH School of Automation Engineering University of Electronic Science and Technology of China key laboratory of intelligent Analysis and Decision on Complex Systems Chongqing University of Posts and Telecommunications Yangtze Delta Region Institute (Huzhou) University of Electronic Science and Technology of China Department of Mathematics and Statistics Texas Tech University

The development of a distributed trajectory-tracking control strategy that is independent of velocity measurements is critical to achieving finite-time tracking control of autonomous underwater vehicle(AUV) systems. In this study, a group of heterogeneous AUV systems with intermittent communication links is considered and a finite-time trajectory-tracking control strategy is developed. The strategy includes two observers and one controller proposed for each follower-AUV. The first observer, a hybrid finite-time observer,estimates the state of the leader, whereas the second observer, which relies only on the position measurement,is proposed to estimate the states of the follower-AUV itself. In addition, a distributed trajectory-tracking controller is designed using the states estimated by the intermittent communication network even without velocity measurements. A homogeneous technique is utilized to prove that all followers can track the leader in a finite time. Finally, the effectiveness of the developed finite-time tracking control strategy is illustrated by numerical simulations.

关键词： distributed observer finite-time tracking homogeneous technique intermittent communication multiple heterogeneous AUVs

control Strategies for Digital Twin Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 170-180页

作者： Guo-Ping Liu IEEE the Center for control science and technology Southern University of Science and TechnologyShenzhen 518055China

With the continuous breakthrough in information technology and its integration into practical applications, industrial digital twins are expected to accelerate their development in the near future. This paper studies various control strategies for digital twin systems from the viewpoint of practical *** make full use of advantages of digital twins for control systems, an architecture of digital twin control systems, adaptive model tracking scheme, performance prediction scheme, performance retention scheme, and fault tolerant control scheme are proposed. Those schemes are detailed to deal with different issues on model tracking, performance prediction, performance retention, and fault tolerant control of digital twin systems. Also, the stability of digital twin control systems is analysed. The proposed schemes for digital twin control systems are illustrated by examples.

关键词： Digital twin control systems fault tolerant control model tracking performance prediction performance retention

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