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Safe Q-Learning for Data-Driven Nonlinear Optimal Control With Asymmetric state Constraints

IEEE/CAA Journal of Automatica Sinica 2024年第12期11卷 2408-2422页

作者： Mingming Zhao Ding Wang Shijie Song Junfei Qiao the School of Information Science and Technology the Beijing Key Laboratory of Computational Intelligence and Intelligent Systemthe Beijing Laboratory of Smart Environmental Protectionand the Beijing Institute of Artificial IntelligenceBeijing University of Technology.Beijing 100124China IEEE the School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

This article develops a novel data-driven safe Q-learning method to design the safe optimal controller which can guarantee constrained states of nonlinear systems always stay in the safe region while providing an optimal ***,we design an augmented utility function consisting of an adjustable positive definite control obstacle function and a quadratic form of the next state to ensure the safety and ***,by exploiting a pre-designed admissible policy for initialization,an off-policy stabilizing value iteration Q-learning(SVIQL)algorithm is presented to seek the safe optimal policy by using offline data within the safe region rather than the mathematical ***,the monotonicity,safety,and optimality of the SVIQL algorithm are theoretically *** obtain the initial admissible policy for SVIQL,an offline VIQL algorithm with zero initialization is constructed and a new admissibility criterion is established for immature iterative ***,the critic and action networks with precise approximation ability are established to promote the operation of VIQL and SVIQL ***,three simulation experiments are conducted to demonstrate the virtue and superiority of the developed safe Q-learning method.

关键词： Adaptive critic control adaptive dynamic programming(ADP) control barrier functions(CBF) stabilizing value iteration Q-learning(SVIQL) state constraints

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Exploring implicit influence for social recommendation based on GNN

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Soft Computing 2024年第19期28卷 11001-11014页

作者： Liu, Zhewei Yang, Peilin Hao, Qingbo Zheng, Wenguang Xiao, Yingyuan Engineering Research Center of Learning-Based Intelligent System Ministry of Education Tianjin University of Technology Tianjin China Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology Tianjin University of Technology Tianjin China

In recent years, the method of using graph neural networks (GNN) to learn users’ social influence has been widely applied to social recommendation and has shown effectiveness, but several important challenges have not been well addressed: (i) Most work fails to consider the user interests (historical user-item interactions) when first building user-user social relationships, which can make it difficult to capture accurate user embedding and thus prevent the model from better exploring the users’ social influence;(ii) Most of the current methods do not build social neighbors (with the same item-user interaction) that belong to the item and do not aggregate information from the perspective of social neighbors, which makes it possible for the item to lose a lot of details when expressing the user’s interest factors. Therefore, to address the above challenges, we propose Exploring Implicit Influence for Social Recommendation Based on GNN (EIIGNN). First, we construct the initial user embedding with user-item interaction information and use the implicit modeling module in user modeling to explore the implicit influence of interest factors on users. In addition, EIIGNN models the social graph structure of item (an item-item graph) so that item can aggregate information from the perspective of their social neighbors, which helps the model learn a more accurate representation of the item. Finally, extensive experimental results on two real-world datasets clearly demonstrate the effectiveness of EIIGNN. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Graph neural networks

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Interval analysis for neural networks with application to fault detection

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Science China(Information Sciences) 2024年第11期67卷 222-237页

作者： Zhenhua WANG Youdao MA Song ZHU Thach Ngoc DINH Yi SHEN Department of Control Science and Engineering Harbin Institute of Technology National Key Laboratory of Complex System Control and Intelligent Agent Cooperation School of Mathematics China University of Mining and Technology The CEDRIC-Lab Conservatoire National des Arts et Métiers (CNAM)

This paper investigates an interval analysis method for neural networks and applies it to fault detection for systems with unknown but bounded measurement noise. First, a novel interval analysis method is presented, which can compute the bounds of the output of a feedforward neural network subject to a bounded input. By applying the proposed interval analysis method to a network trained with fault-free system data, adaptive thresholds for fault detection are computed. Finally, one can acquire fault detection results via a fault detection strategy. The proposed method can achieve tight bounds of the network output and employ simple operations, which leads to accurate fault detection results and a low computational burden.A numerical simulation and an experiment on an AC servo motor are given to illustrate the effectiveness and superiority of the proposed method.

关键词： interval analysis feedforward neural network fault detection adaptive thresholds

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The Autonomous Pipeline Navigation of a Cockroach Bio-Robot with Enhanced Walking Stimuli

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Cyborg and Bionic systems 2023年第1期4卷 47-55页

作者： Songsong Ma Yuansheng Chen Songlin Yang Shen Liu Lingqi Tang Bing Li Yao Li State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbinChina Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of TechnologyShenzhenChina School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhenChina The Biorobotics Institute Scuola Superiore Sant'AnnaPisaItaly

Tens of crawling bio-robots with cockroaches as the mobile platform have been developed with various *** with artificial crawling robots of the same size,they revealed better flexibility,larger payload,and stronger *** features made bio-robots ideal for pipeline inspection scenarios because the advancements in locomotion mechanisms and efficient power systems are still hurdles for current artificial *** this study,we controlled the bio-robot to crawl in the confined dark pipeline and achieved autonomous motion control with the help of an onboard sensing ***,a micro-camera was mounted on the electronic backpack of the cockroach for image collection,and an IMU sensor was used to compute its body *** electronic backpack transmitted images to the host computer for junction recognition and distance ***,the insect's habituation to electrical stimulation has long been an uncertain factor in the control of ***,a synergistic stimulation strategy was proposed to markedly reduce the habituation and increase the number of effective turning controls to over 100 *** is also found that both the increase of payload and the application of stimulations could promote the metabolic rate by monitoring carbon dioxide *** the integration of synergistic stimulation and autonomous control,we demonstrated the fully autonomous pipeline navigation with our cockroach bio-robot,which realized the cycle number of approximately 10 in a *** research provides a novel technology that has the potential for practical applications in the future.

关键词： robot artificial Robot

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Two Stages Segmentation Algorithm of Breast Tumor in DCE-MRI Based on Multi-Scale Feature and Boundary Attention Mechanism

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Computers, Materials & Continua 2024年第7期80卷 1543-1561页

作者： Bing Li Liangyu Wang Xia Liu Hongbin Fan Bo Wang Shoudi Tong School of Automation Harbin University of Science and TechnologyHarbin150080China Heilongjiang Provincial Key Laboratory of Complex Intelligent System and Integration Harbin150080China School of Computer Engineering Technology Guangdong Institute of Science and TechnologyZhuhai519090China

Nuclearmagnetic resonance imaging of breasts often presents complex *** tumors exhibit varying sizes,uneven intensity,and indistinct *** characteristics can lead to challenges such as low accuracy and incorrect segmentation during tumor ***,we propose a two-stage breast tumor segmentation method leveraging multi-scale features and boundary attention ***,the breast region of interest is extracted to isolate the breast area from surrounding tissues and ***,we devise a fusion network incorporatingmulti-scale features and boundary attentionmechanisms for breast tumor *** incorporate multi-scale parallel dilated convolution modules into the network,enhancing its capability to segment tumors of various sizes through multi-scale convolution and novel fusion ***,attention and boundary detection modules are included to augment the network’s capacity to locate tumors by capturing nonlocal dependencies in both spatial and channel ***,a hybrid loss function with boundary weight is employed to address sample class imbalance issues and enhance the network’s boundary maintenance capability through additional *** was evaluated using breast data from 207 patients at RuijinHospital,resulting in a 6.64%increase in Dice similarity coefficient compared to the *** results demonstrate the superiority of the method over other segmentation techniques,with fewer model parameters.

关键词： Dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) breast tumor segmentation multi-scale dilated convolution boundary attention the hybrid loss function with boundary weight

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Task-oriented Hierarchical Control of Modular Soft Robots with External Vision Guidance

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Journal of Bionic Engineering 2022年第3期19卷 657-667页

作者： Xin Sui Tianjiao Zheng Jian Qi Zhiyuan Yang Ning Zhao Jie Zhao Hegao Cai Yanhe Zhu State Key Laboratory of Robotics and System Harbin Institute of Technology(HIT)Harbin150001China

General,high-precision theoretical modeling method is not well developed in the field of soft robotics,which holds back motion control and practical application of soft *** concept of modularization brings novel structure,novel locomotion patterns as well as novel control method for soft *** paper presents the concept of hierarchical control method for modular soft robot system and a H-configuration pneumatic modular soft robot is designed as the control *** H-configuration modular soft robot is composed of two basic motion units that take worm-like locomotion *** locomotion principle of the basic motion unit is analyzed and the actuation sequence is optimized by evolution strategy in VOXCAD simulation *** differential drive method is applied to the H-configuration modular soft robot with multi motion modes and vision sensor is used to control the motion mode of the *** H-configuration modular soft robot and the basic motion unit are assembled by a cubic soft module made of silicone ***,connection mechanism is designed to ensure that the soft modules can be assembled in any direction and *** are conducted to verify the effect of the hierarchical control method of the modular soft robots.

关键词： Soft robot Modular robot Locomotion pattern optimization VOXCAD simulation software Vision feedback control

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A comparison on the effects of coal fines and sand fouling on the shear behaviors of railway ballast using large scale direct shear tests

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Journal of Traffic and Transportation Engineering(English Edition) 2025年第1期12卷 52-67页

作者： Xu Zhang Shunying Ji Yang Feng Yongjun Li Chunfa Zhao School of Civil and Transportation Engineering Guangdong University of TechnologyGuangzhou 510006China State Key Laboratory of Rail Transit Vehicle System Southwest jiaotong UniversityChengdu 610031China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China

Railway ballast is easily contaminated by different fouling material and the fouled ballast always causes the deterioration of railway *** previous studies focused on the effect of a certain kind of fouling material on ballast performance,but few studies compared the influence of different fouling *** paper presents a series of direct shear tests on the clean ballast and the fouled ballast mixed with coal fines or sand to understand the effects of different fouling material.A unified empirical model is proposed to well capture the shear stress-displacement responses of the clean and fouled *** equations are also obtained to characterize the variation of the nonlinear shear strength envelope of the fouled ballast with the fouling *** on these equations,a simple method is proposed to predict the shear strength of the fouled ballast using the shear test results of clean *** measured results demonstrate significant differences between the effects of coal fines and sand on the shear behaviors of ballast,to which particular attention should be paid in order to take targeted maintenance measures for the fouled *** mechanisms for the different effects of coal fines and sand are also analyzed to understand the roles that various fouling material plays in the fouled ballast.

关键词： Railway ballast Fouled ballast Shear strength Direct shear test Contamination

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A Simple Control Scheme with Model Predictive Control-Based Footstep Planner and Virtual Model Control for Planar Biped Robot 16th

A Simple Control Scheme with Model Predictive Control-Based ...

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16th International Conference on Modelling, Identification and Control, ICMIC 2024

作者： Heng, Shuai Song, Chao Chen, Boyang Zhang, Yue Zang, Xizhe Zhao, Jie State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150080 China

ISBN: (纸本)9789819617760

In this paper, our objective is to achieve stable walking for biped robots using a simple yet powerful control scheme. This control scheme consists of a planning and control framework. For the motion planner, we utilize the Linear Inverted Pendulum Model as the equations of motion for the biped. Model Predictive Control is applied to plan the Zero Moment Point (ZMP) for future steps. Trajectories for the swing foot and base are generated based on the planned ZMP. Subsequently, a straightforward and intuitive control method called Virtual Model Control is employed to calculate control torques for tracking the generated trajectories. Finally, simulations conducted on flat-foot bipedal robots in MuJoCo validate the effectiveness of the proposed control scheme in achieving stable walking and attaining the desired locomotion velocity. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Predictive control systems

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Atomistic study on the microscopic mechanism of grain boundary embrittlement induced by small dense helium bubbles in iron

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Nuclear Science and Techniques 2024年第3期35卷 84-95页

作者： Lei Peng Yong-Jie Sun Jing-Yi Shi Yi-Fei Liu Shang-Ming Chen Liu-Liu Li State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion *** order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics *** results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile *** atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation ***,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at *** bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation ***,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.

关键词： Helium bubble Grain boundary Embrittlement Reduced activation ferritic martensitic steel Molecular dynamics Bain path

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Will the fibers of the future be considered fibers?

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National Science Review 2024年第10期11卷 15-17页

作者： Dewen Xu Ya Liu Hailiang Wang Wei Yan Changjun Jiang Meifang Zhu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Department of Computer Science and Technology Tongji University

Fiber materials are key materials that have changed human history and promoted the progress of human civilization. In ancient times, humans used feathers and animal skins for clothing, and later they widely employed natural fibers such as cotton, hemp, silk and wool to make fabrics(Fig. 1a). Chinese ancestors had mastered the art of natural fiber weaving as early as the Neolithic *** thousand years ago, people were already familiar with and adept at techniques for spinning natural fibers [1].

关键词： future will considered fibers

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