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Inexact proximal gradient algorithm with random reshuffling for nonsmooth optimization

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Science China(Information Sciences) 2025年第1期68卷 219-237页

作者： Xia JIANG Yanyan FANG Xianlin ZENG Jian SUN Jie CHEN National key Lab of autonomous Intelligent Unmanned Systems School of AutomationBeijing Institute of Technology Beijing Institute of Technology chongqing Innovation Center School of Electronic and Information Engineering Tongji University

Proximal gradient algorithms are popularly implemented to achieve convex optimization with nonsmooth regularization. Obtaining the exact solution of the proximal operator for nonsmooth regularization is challenging because errors exist in the computation of the gradient; consequently, the design and application of inexact proximal gradient algorithms have attracted considerable attention from researchers. This paper proposes computationally efficient basic and inexact proximal gradient descent algorithms with random reshuffling. The proposed stochastic algorithms take randomly reshuffled data to perform successive gradient descents and implement only one proximal operator after all data pass through. We prove the convergence results of the proposed proximal gradient algorithms under the sampling-without-replacement reshuffling *** computational errors exist in gradients and proximal operations, the proposed inexact proximal gradient algorithms can converge to an optimal solution neighborhood. Finally, we apply the proposed algorithms to compressed sensing and compare their efficiency with some popular algorithms.

关键词： proximal operator random reshuffling inexact computation compressed sensing nonsmooth optimization

Research on a fiber sensing system for metal ion detection based on SPF-PCF-SPF structure and coated LPFG

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Optoelectronics Letters 2024年第4期20卷 211-215页

作者： GUO Junqi ZHOU Yanfang ZHENG Wenyue XU Qianwen LIU Yu LI Renpu chongqing key laboratory of autonomous navigation and microsystem Chongqing University of Post and TelecommunicationsChongqing 400065China chongqing Engineering Research Center of Intelligent Sensing Technology and microsystem Chongqing University of Posts and TelecommunicationsChongqing 400065China

In order to provide a method for accurately detecting the concentration and types of heavy metal ions in water,a fluid ion detection system is *** consists of a side-polished fiber-assisted fluid structure and a long-period fiber grating(LPFG)coated with a metal chelating agent *** this study,both theoretical and experimental investigations are conducted to examine the sensing characteristics of the system towards copper ion and iron ion *** results demonstrate that under the premise of ensuring solution flow,the system can achieve specific identification of different types of heavy metal ***,it exhibits concentration sensing sensitivities of 9.23×10^(4) mL·nm/mol and 7.13×10^(4) mL·nm/mol for copper sulfate(CuSO_(4))and ferric chloride(FeCl_(3))solutions,***,this sensing system offers the potential for real-time detection of metal ions.

关键词： system fiber structure

A biological fluid fiber Sagnac sensor based on SPF-PCF-SPF structure

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Optoelectronics Letters 2023年第4期19卷 210-214页

作者： GUO Junqi WANG Changle DI Ke LI Zhehao LI Renpu LIU Yu chongqing key laboratory of autonomous navigation and microsystem Chongqing University of Post and TelecommunicationsChongqing 400065China chongqing Engineering Research Center of Intelligent Sensing Technology and microsystem Chongqing University of Posts and TelecommunicationsChongqing 400065China

A biological solution concentration sensor based on a side-polished fiber(SPF)assisted fluid system is *** birefringence properties of the asymmetrically filled fluid in this structure and the relationship between the concentration of the biological solution and the refractive index are theoretically *** was found that the interference peaks had red-shifted with increasing concentration.A sensing sensitivity of 1.3871×10^(4)nm·mL/mol at 14.68×10^(-4)mol/mL was achieved within the experimental range after different concentrations of arginine solutions were injected into the sensing *** sensing system can also be applied to measure the concentration of other biological solutions,providing the feasibility of real-time detection of biological solutions.

关键词： fiber fluid structure

Microstructural,magnetic and dielectric performance of rare earth ion(Sm^(3+))-doped MgCd ferrites

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Chinese Physics B 2022年第7期31卷 643-647页

作者： Dandan Wen Xia Chen Dasen Luo Yi Lu Yixin Chen Renpu Li Wei Cui Doctoral Research Station of chongqing key laboratory of Optoelectronic Information Sensing and Transmission Technology Chongqing University of Post and TelecommunicationsChongqing 400065China State key laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China chongqing key laboratory of autonomous navigation and microsystem Chongqing University of Post and TelecommunicationsChongqing 400065China

The combined effects of Sm^(3+)substitution together with the addition of 3 wt%Bi_(2)O_(3)endow Mg Cd ferrites with excellent magnetic permeability and dielectric *** concentrations of Sm^(3+)(x=0,0.03,0.06,0.09,0.12and 0.15)were employed to modify the permeability(μ)and permittivity(ε)of the Mg Cd ferrites.X-ray diffraction,scanning electron microscopy(SEM),vibrating sample magnetometry and vector network analysis techniques were used to characterize the *** measurement results reveal that the ferrites processed a saturation magnetization of up to 36.8 emu/g and coercivity of up to 29.2 Oe via the conventional solid-state reaction *** surface morphology SEM confirms that with increasing Sm^(3+)concentration,the grain shape changes from a polygon to a ***,the dielectric permittivity can reach a value of *** excellent properties obtained in Sm^(3+)-substituted Mg ferrites suggest that they could be promising candidates for modern high-frequency antenna substrates or multilayer devices.

关键词： ferrites Sm^(3+)ions substitution magnetic permeability dielectric permittivity

Optic-electronics stereo system for spatial position measurement of railway track

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Optoelectronics Letters 2022年第7期18卷 434-439页

作者： Igor Konyakhin XIAO Han LI Renpu YANG Jiawen HUANG Guifu TAN Xin Faculty of Engineering Research Applied Optic ITMO UniversitySaint Petersburg 197101Russia chongqing key laboratory of autonomous navigation and microsystem Chongqing University of Post and TelecommunicationsChongqing 400065China

Railway departments in various countries are looking for a technology with convenient operation,low price,excellent measurement performance and stability for spatial position measurement of railway ***,we design an optic-electronics stereo system based on the principle of optical stereo *** experimental verification in the real railway environment shows that the performance of the system is that the longitudinal relative displacement measurement range is 200—10000 mm,the relative distance measurement range is 4500 mm and the measured root mean square(RMS)error value is less than 1.1 mm in the whole ***,it meets the relevant needs of the Russian Ministry of railways.

关键词： measurement. system price

A data and physical model dual-driven based trajectory estimator for long-term navigation

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Defence Technology（防务技术） 2024年第10期40卷 78-90页

作者： Tao Feng Yu Liu Yue Yu Liang Chen Ruizhi Chen School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong Kong999077China chongqing key laboratory of autonomous navigation and microsystem Chongqing University of Post and TelecommunicationsChongqing400065China State key laboratory of Information Engineering in Surveying Mapping and Remote Sensing(LIESMARS)Wuhan UniversityWuhan430000China

Long-term navigation ability based on consumer-level wearable inertial sensors plays an essential role towards various emerging fields, for instance, smart healthcare, emergency rescue, soldier positioning et al. The performance of existing long-term navigation algorithm is limited by the cumulative error of inertial sensors, disturbed local magnetic field, and complex motion modes of the pedestrian. This paper develops a robust data and physical model dual-driven based trajectory estimation(DPDD-TE) framework, which can be applied for long-term navigation tasks. A Bi-directional Long Short-Term Memory(Bi-LSTM) based quasi-static magnetic field(QSMF) detection algorithm is developed for extracting useful magnetic observation for heading calibration, and another Bi-LSTM is adopted for walking speed estimation by considering hybrid human motion information under a specific time period. In addition, a data and physical model dual-driven based multi-source fusion model is proposed to integrate basic INS mechanization and multi-level constraint and observations for maintaining accuracy under long-term navigation tasks, and enhanced by the magnetic and trajectory features assisted loop detection algorithm. Real-world experiments indicate that the proposed DPDD-TE outperforms than existing algorithms, and final estimated heading and positioning accuracy indexes reaches 5° and less than 2 m under the time period of 30 min, respectively.

关键词： Long-term navigation Wearable inertial sensors Bi-LSTM QSMF Data and physical model dual-driven

Adaptive Control With Guaranteed Transient Behavior and Zero Steady-State Error for Systems With Time-Varying Parameters

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IEEE/CAA Journal of Automatica Sinica 2022年第6期9卷 1073-1082页

作者： Hefu Ye Yongduan Song chongqing key laboratory of autonomous Systems Institute of Artificial IntelligenceSchool of AutomationChongqing UniversityChongqing 400044China IEEE

It is nontrivial to achieve global zero-error regulation for uncertain nonlinear *** underlying problem becomes even more challenging if mismatched uncertainties and unknown time-varying control gain are involved,yet certain performance specifications are also *** this work,we present an adaptive control method,which,without the persistent excitation(PE)condition,is able to ensure global zero-error regulation with guaranteed output performance for parametric strict-feedback systems involving fast time-varying parameters in the feedback path and input *** development of our control scheme benefits from generalized-dependent and-dependent functions,a novel coordinate transformation and“congelation of variables”*** theoretical analysis and numerical simulation verify the effectiveness and benefits of the proposed method.

关键词： Adaptive control global property guaranteed performance uncertain nonlinear systems

Geometry-based distributed arc-consistency method formultiagent planning and scheduling

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Science China(Technological Sciences) 2019年第1期62卷 133-143页

作者： XU Rui LI ZhaoYu CUI PingYuan Institute of Deep Space Exploration Technology School of Aerospace Engineering Beijing Institute of Technology key laboratory of autonomous navigation and Control for Deep Space Exploration Ministry of Industry and Information Technology

This research focuses on building a distributed algorithm for planning and scheduling multiple agents to help people deal with events beyond their cognitive capacity, such as car assembly, factory management, spacecraft constellation, etc. We address not only the efficiency of the algorithm but also communication and the individual privacy. As to reason over the problems with multiple agents which are distributed but interconnected, a formal account of the Action-centric Multiagent Simple Temporal Problem(AMSTP) is put forward using the representation of geometries. The key technique we build on is a novel distributed arc-consistency algorithm centered by the geometric method called GDAC, which pays attention to how an agent's local subproblem affects other agents' subproblems. The GDAC is based on geometries taking the action rather than the timepoint as a variable, which can deal with continuous intervals and decrease the number of variables. Comprehensive experiments are run and the proposed technique outperforms the competitor and shows considerable merit compared to the centralized algorithm.

关键词： arc consistency multiple agents planning and scheduling

Achieving Given Precision Within Prescribed Time yet With Guaranteed Transient Behavior via Output Based Event-Triggered Control

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IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2059-2067页

作者： Zeqiang Li Yujuan Wang Yongduan Song International Joint laboratory on Safety and Control of autonomous Unmanned Systems School of AutomationChongqing UniversityChongqing 400044China IEEE

It is interesting yet nontrivial to achieve given control precision within user-assignable time for uncertain nonlinear *** underlying problem becomes even more challenging if the transient behavior also needs to be accommodated and only system output is available for *** key design innovations are proposed to circumvent the aforementioned technical difficulties,including the employment of state estimation filters with event-triggered mechanism,the construction of a novel performance scaling function and an error *** contrast to most existing performance based works where the stability is contingent on initial conditions and the maximum allowable steady-state tracking precision can only be guaranteed at some unknown(theoretically infinite)time,in this work the output of the system is ensured to synchronize with the desired trajectory with arbitrarily pre-assignable convergence rate and arbitrarily pre-specified precision within prescribed time,using output only with lower cost of sensing and *** addition,all the closed-loop signals are ensured to be globally uniformly bounded under the proposed control *** merits of the designed control scheme are confirmed by numerical simulation on a ship model.

关键词： Adaptive control nonlinear systems output feedback prescribed performance