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Value iteration algorithm for continuous-time linear quadratic stochastic optimal control problems

science China(Information sciences) 2024年第2期67卷 170-180页

作者： Guangchen WANG Heng ZHANG School of Control Science and Engineering Shandong University

In this study, we investigate a continuous-time infinite-horizon linear quadratic stochastic optimal control problem with multiplicative noise in control and state variables. Using the techniques of stochastic stability, exact observability, and stochastic approximation, a value iteration algorithm is developed to solve the corresponding generalized algebraic Riccati equation. Unlike the existing policy iteration algorithm, this algorithm does not rely on an initial stabilizing control. Further, this algorithm can also be used to compute policy evaluation steps that arise in the policy iteration algorithm. Herein, a simulation example is provided to validate the obtained results.

关键词： stochastic systems optimal control linear quadratic stochastic problem generalized algebraic Riccati equation value iteration algorithm

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Energy Conversion Law of Refuse Gasifi cation/Incineration in Low-Oxygen Plateau Areas—A Case Study of Lhasa,China

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Transactions of Tianjin University 2024年第6期30卷 498-507页

作者： Jun He Yubin Hong Hong Li Yang Yao Yongjian Xie Xinye Cheng Diyun Chen Lihua Dong School of Environmental Science and Engineering Tianjin UniversityTianjin 300072China Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources School of Environmental Science and EngineeringGuangzhou UniversityGuangzhou 510006China

Combusting refuse for energy production is promising for their treatment and disposal. However, because of geographical constraints, there has not been a stable model for the energy utilization of refuse in low-oxygen plateau areas. This paper took Lhasa as an example to conduct gasification and incineration experiments on local representative combustible refuse,and relevant energy conversion laws were investigated. Results showed that under gasification and incineration modes, the energy conversion rate of any component of refuse can reach 75% and 85% in low-oxygen plateau areas at temperatures of 450 and 650 ℃, respectively, which were 5%–10% lower than those in plain areas. The regional distribution of energy conversion of refuse in Lhasa showed that the energy conversion rate under the gasification mode was 3%–5% lower than that of the incineration mode at 450 and 650 ℃. In terms of temperature, the energy conversion rates of refuse were 5%–10% lower at 450 ℃ than those at 650 ℃, but an energy conversion rate of more than 85% can still be achieved. Thus, gasification, incineration, or gasification-assisted secondary incineration at temperatures of at least 450 ℃ is suitable for energy recovery of refuse in low-oxygen plateau areas.

关键词： Low-oxygen plateau areas Energy conversion Gasifi cation and incineration Refuse

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EASI: Evolutionary Adversarial Simulator Identification for Sim-to-Real Transfer 38

EASI: Evolutionary Adversarial Simulator Identification for ...

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38th Conference on Neural Information Processing Systems, NeurIPS 2024

作者： Dong, Haoyu Fu, Huiqiao Xu, Wentao Zhou, Zhehao Chen, Chunlin Department of Control Science and Intelligent Engineering School of Management and Engineering Nanjing University China

Reinforcement Learning (RL) controllers have demonstrated remarkable performance in complex robot control tasks. However, the presence of reality gap often leads to poor performance when deploying policies trained in simulation directly onto real robots. Previous sim-to-real algorithms like Domain Randomization (DR) requires domain-specific expertise and suffers from issues such as reduced control performance and high training costs. In this work, we introduce Evolutionary Adversarial Simulator Identification (EASI), a novel approach that combines Generative Adversarial Network (GAN) and Evolutionary Strategy (ES) to address sim-to-real challenges. Specifically, we consider the problem of sim-to-real as a search problem, where ES acts as a generator in adversarial competition with a neural network discriminator, aiming to find physical parameter distributions that make the state transitions between simulation and reality as similar as possible. The discriminator serves as the fitness function, guiding the evolution of the physical parameter distributions. EASI features simplicity, low cost, and high fidelity, enabling the construction of a more realistic simulator with minimal requirements for real-world data, thus aiding in transferring simulated-trained policies to the real world. We demonstrate the performance of EASI in both sim-to-sim and sim-to-real tasks, showing superior performance compared to existing sim-to-real algorithms. © 2024 Neural information processing systems foundation. All rights reserved.

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Combining first principles and machine learning for rapid assessment response of WO_(3) based gas sensors

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International Journal of Mining science and Technology 2024年第12期34卷 1765-1772页

作者： Ran Zhang Guo Chen Shasha Gao Lu Chen Yongchao Cheng Xiuquan Gu Yue Wang School of Medical Information and Engineering Xuzhou Medical UniversityXuzhou 221000China School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China

The rapid advancement of gas sensitive properties in metal oxides is crucial for detecting hazardous gases in industrial and coal mining ***,the conventional experimental trial and error approach poses significant challenges and resource consumption for the high throughput screening of gas sensitive ***,this paper introduced a novel screening approach that integrates first principles with machine learning(ML)to rapidly predict the gas sensitivity of ***,a comprehensive database of multi-physical parameters was established by modeling various adsorption sites on the surface of WO3,which serves as a representative *** density functional theory(DFT)is one of the first principles,DFT calculations were conducted to derive essential multi-physical parameters,including bandgap,density of states(DOS),Fermi level,adsorption energy,and structural modifications resulting from *** collected data was subsequently utilized to develop a cor-relation model linking the multi-physical parameters to gas sensitive performance using intelligent *** model’s performance was assessed through receiver operating characteristic(ROC)curves,confusion matrices,and other evaluation metrics,ultimately achieving a prediction accuracy of 90%for identifying key features influencing gas adsorption *** proposed strategy for predicting the gas sensitive characteristics of materials holds significant potential for application in identifying addi-tional gas sensitive properties across various materials.

关键词： Machine learning Density functional theory Rapid assessment Gas sensor

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Contour Detection Algorithm forαPhase Structure of TB6 Titanium Alloy fused with Multi-Scale Fretting Features

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Chinese Journal of Mechanical engineering 2024年第5期37卷 499-509页

作者： Fei He Yan Dou Xiaoying Zhang Lele Zhang School of Information Science and Engineering Yanshan UniversityQinhuangdao 066004China Hebei Provincial Key Laboratory of Software Engineering Yan shan University Qinhuangdao 066004China School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

Aiming at the problems of inaccuracy in detecting theαphase contour of TB6 titanium *** combining computer vision technology with human vision mechanisms,the spatial characteristics of theαphase can be simulated to obtain the contour ***,an algorithm forαphase contour detection of TB6 titanium alloy fused with multi-scale fretting features is ***,through the response of the classical receptive field model based on fretting and the suppression of new non-classical receptive field model based on fretting,the information maps of theαphase contour of the TB6 titanium alloy at different scales are obtained;then the information map of the smallest scale contour is used as a benchmark,the neighborhood is constructed to judge the deviation of other scale contour information,and the corresponding weight value is calculated;finally,Gaussian function is used to weight and fuse the deviation information,and the contour detection result of TB6 titanium alloyαphase is *** the Visual Studio 2013 environment,484 metallographic images with different temperatures,strain rates,and magnifications were *** results show that the performance evaluation F value of the proposed algorithm is 0.915,which can effectively improve the accuracy ofαphase contour detection of TB6 titanium alloy.

关键词： TB6 titanium alloyαphase Multi-scale fretting features Contour detection

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3D-printed MoS_(2)/Ni electrodes with excellent electro-catalytic performance and long-term stability for dechlorination of florfenicol

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Journal of Environmental sciences 2024年第3期137卷 420-431页

作者： Jianhui Xu Pengxu Wang Shenggui Chen Lei Li Dan Li Yunfei Zhang Qi Wu Jinhong Fan LumingMa School of Environment and Civil Engineering Dongguan University of TechnologyDongguan 523808China School of Art and Design Guangzhou Panyu PolytechnicGuangzhou 511483China National Engineering Research Center for Urban Pollution Control State Key Laboratory of Pollution Control and Resources ReuseCollege of Environmental Science and EngineeringTongji UniversityShanghai 200092China Dongguan Institute of Science and Technology Innovation Dongguan University of TechnologyDongguan 523808China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)*** a cathode,the obtained 3D-MoS_(2)/Ni could maintain a degradation rate above 94.0%for forfenicol(FLO)when repeatedly used 50 times in *** also found that the removal rate of FLO by 3D-MoS_(2)/Ni was about 12 times higher than that of 3D-printed pure Ni(3D-Ni),attributed to the improved accessibility of H^(*).In addition,the electrochemical characterization results showed that the electrochemically active surface area of the 3D-MoS_(2)/Ni electrode is about 3-fold higher than that of the 3D-Ni electrode while the electrical resistance is 4 times *** on tert-butanol suppression,electron paramagnetic resonance and triple quadrupole mass spectrometer experiments,a“dual path”mechanism and possible degradation pathway for the dechlorination of FLO by 3D-MoS_(2)/Ni were ***,we also investigated the impacts of the cathode potential and the initial pH of the solution on the degradation of ***,this study reveals that the SLM 3D printing technique is a promising approach for the rapid fabrication of high-stability metal electrodes,which could have broad application in the control of water contaminants in the environmental field.

关键词： 3D-print Electroreduction MoS_(2)/Ni Antibiotic Florfenicol

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Optimal crater landmark selection based on optical navigation performance factors for planetary landing

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Chinese Journal of Aeronautics 2023年第3期36卷 254-270页

作者： Yi XIU Shengying ZHU Rui XU Maodeng LI School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Autonomous Navigation and Control for Deep Space Exploration Ministry of Industry and Information TechnologyBeijing 100081China Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of EducationBeijing 100081China Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control EngineeringBeijing 100091China

Planetary craters are natural navigation landmarks that widely exist and are easily *** navigation based on crater landmarks has become an important autonomous navigation method for planetary *** to the increase in observed crater landmarks and the limitation of onboard computation,the selection of good crater landmarks has gradually become a research hotspot in the field of landmark-based optical *** paper designs a fast crater landmark selection method,which not only considers the configuration observability of crater subsets but also focuses on the influence on navigation performance arising from the measurement uncertainty and the matching confidence of craters,which is different from other landmark selection *** factor of measurement uncertainty,which is anisotropic,correlated and nonidentically distributed,is quantified and integrated into selection based on crater pairing detection and localization error *** addition,the concept of the crater matching confidence factor is introduced,which reflects the possibility of 2D projection measurements corresponding to 3D *** with the configuration observability factor,the crater landmark selection indicator is ***,the effectiveness of the proposed method is verified by Monte Carlo simulations.

关键词： Crater-based optical navigation Crater landmark selection Crater matching Measurement uncertainty Planetary landing

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Active Fault Tolerant control for PEM Fuel Cells Under Cathode Flooding

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IEEE Transactions on Transportation Electrification 2025年第3期11卷 8043-8053页

作者： Chen, Jian Yan, Chizhou Kumar, Lalitesh Jin, Lei Li, Xinyu Southern University of Science and Technology School of Automation and Intelligent Manufacturing Shenzhen518055 China Zhejiang University School of Mechanical Engineering Hangzhou310058 China Zhejiang University College of Control Science and Engineering Hangzhou310027 China

Proper fault tolerant control is a key issue to extend the lifetime of proton exchange membrane fuel cells. This paper proposes a fault tolerant control algorithm to realize performance recovery under flooding. A water transfer model of the PEM fuel cells is established and verified, and a flooding fault indicator is developed for diagnosing the fault in real time. Thereafter, an active fault tolerant controller based on the water transfer model and the fault indicator is developed in order to recover the performance characteristics of the PEM fuel cells. Experimental results show that the proposed fault indicator can accurately identify the flooding, and the fault tolerant controller can effectively suppress the water management failure. Thereby improving the reliability of the PEM fuel cells. © 2015 IEEE.

关键词： Fault detection

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Robust Stability and Stabilizability Conditions for Time-Delay Systems Under Stochastic Uncertainties

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IEEE Transactions on Automatic control 2024年第6期70卷 4037-4044页

作者： Chen, Jianqi Mao, Qi Zhao, Di Chen, Chao Nanjing University Center for Advanced Control and Smart Operations Suzhou China Nanjing Normal University School of Electrical and Automation Engineering Nanjing China Tongji University Department of Control Science and Engineering Shanghai Institute of Intelligent Science and Technology Shanghai China Leuven3001 Belgium

This study first explores the mean-square robust stability problem of stable continuous-time linear time-invariant systems subject to stochastic multiplicative uncertainties with prescribed variance bounds. The internal structures of uncertainties, however, are not presumed to cope with diverse random noises and errors arising from networked channels. A necessary and sufficient mean-square stability condition is obtained involving a novel small-gain type characterization. Next, we consider the output feedback controller synthesis problem of networked control systems facing stochastic multiplicative uncertainties and intrinsic channel-wise time delays simultaneously. Based on the obtained mean-square stability condition, further, we develop a fundamental necessary and sufficient condition of mean-square stabilizability explicitly. Such a condition equivalently determines that an open-loop unstable system can be stabilized by output feedback in the mean-square sense. Finally, an analysis of delay robustness is elaborated, in which the mean-square stabilizability condition is extended to the case tolerating uncertain but upper-bounded time delays. Overall, this study provides a comprehensive analysis of the robust mean-square stability and mean-square stabilizability of time-delay systems under stochastic uncertainties, which can have practical implications for networked control systems. © 1963-2012 IEEE.

关键词： Continuous time systems

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Dynamic coupling of ferrihydrite transformation and associated arsenic desorption/redistribution mediated by sulfate-reducing bacteria

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Journal of Environmental sciences 2024年第1期135卷 39-50页

作者： Wenjing Zhou Huiyan Zhu Shiwen Hu Bowei Zhang Kun Gao Zhi Dang Chongxuan Liu State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSouth China University of TechnologyGuangzhou 510006China

Sulfate-reducing bacteria play an important role in the geochemistry of iron(oxyhydr)oxide and arsenic(As)in natural environments;however,the associated reaction processes are yet to be fully *** this study,batch experiments coupled with geochemical,spectroscopic,microscopic,and thermodynamic analyses were conducted to investigate the dynamic coupling of ferrihydrite transformation and the associated As desorption/redistribution mediated by Desulfovibrio vulgaris(***).The results indicated that *** could induce ferrihydrite transformation via S^(2-)-driven and direct reduction *** the absence of SO_(4)^(2-),*** directly reduced ferrihydrite,and As desorption and re-sorption occurred simultaneously during the partial transformation of ferrihydrite to *** increase in SO_(4)^(2-)loading promoted the S^(2-)-driven reduction of ferrihydrite and accelerated the subsequent mineralogical *** the low and medium SO_(4)^(2-)treatments,ferrihydrite was completely transformed to a mixture of magnetite and mackinawite,which increased the fraction of As in the residual phase and stabilized *** the high SO_(4)^(2-)treatment,although the replacement of ferrihydrite by only mackinawite also increased the fraction of As in the residual phase,22.1%of the total As was released into the solution due to the poor adsorption affinity of As to mackinawite and the conversion of As^(5+)to As^(3+).The mechanisms of ferrihydrite reduction,mineralogy transformation,and As mobilization and redistribution mediated by sulfate-reducing bacteria are closely related to the surrounding SO_(4)^(2-)*** results advance our understanding of the biogeochemical behavior of Fe,S,and As,and are helpful for the risk assessment and remediation of As contamination.

关键词： Sulfate-reducing bacteria Arsenic Ferrihydrite Transformation Redistribution

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