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New design of active disturbance rejection control for nonlinear uncertain systems with unknown control input gain

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Science China(Information Sciences) 2022年第4期65卷 156-168页

作者： sen chen Zhixiang chen Yi HUANG Zhi-Liang ZHAO School of Mathematics and Statistics Shaanxi Normal University Department of Missile Launching and Power Rocket Force Sergeant Academy Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

The paper considers the control problem for uncertain nonlinear systems with unknown control input gain. Based on the information of control direction rather than the nominal value of control input gain, a new active disturbance rejection control design is proposed. In the proposed design, the extended state observer(ESO) is constructed to estimate the total disturbance containing the uncertainty of control input. Via the estimations from ESO, the control input is generated by a designed dynamical system, which can force the actual input to track the ideal input. Moreover, for a wide class of nonlinear uncertainties, the transient performance of the proposed design is investigated. The theoretical results show that the tracking and estimating errors, as well as the difference between the actual and ideal inputs, can be sufficiently small by tuning the parameter of ESO despite various uncertainties. The experiment of a permanent magnet linear synchronous motor servo system illustrates the effectiveness of the proposed design.

关键词： uncertain system active disturbance rejection control control input gain

Product quality prediction based on RBF optimized by firefly algorithm

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Journal of Systems Engineering and Electronics 2024年第1期35卷 105-117页

作者： HAN Huihui WANG Jian chen sen YAN Manting College of Electronics and Information Engineering Tongji UniversityShanghai 201804China

With the development of information technology,a large number of product quality data in the entire manufacturing process is accumulated,but it is not explored and used *** traditional product quality prediction models have many disadvantages,such as high complexity and low *** overcome the above problems,we propose an optimized data equalization method to pre-process dataset and design a simple but effective product quality prediction model:radial basis function model optimized by the firefly algorithm with Levy flight mechanism(RBFFALM).First,the new data equalization method is introduced to pre-process the dataset,which reduces the dimension of the data,removes redundant features,and improves the data *** the RBFFALFM is used to predict product *** expe riments conducted on real-world product quality datasets validate that the new model RBFFALFM combining with the new data pre-processing method outperforms other previous me thods on predicting product quality.

关键词： product quality prediction data pre-processing radial basis function swarm intelligence optimization algorithm

ArgusDroid: detecting Android malware variants by mining permission-API knowledge graph

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Science China(Information Sciences) 2023年第9期66卷 115-133页

作者： Yude BAI sen chen Zhenchang XING Xiaohong LI College of Intelligence and Computing Tianjin University Research School of Computer Science Australian National University

Malware family variants make minor and relevant changes of behaviors based on the original malware. To analyze and detect family variants, security experts must not only understand malware behaviors but also further observe the correlation between the features of these behaviors. However, the recent data-driven based behavior features are too independent and sometimes too general to obtain a comprehensive profile of the changeable malicious behaviors of family variants derived from the original *** features additionally suffer from limited semantic knowledge which narrows the comprehension of family variants. To this end, in this paper, we propose ArgusDroid that takes advantage of the knowledge graph(KG) to construct a permission-API knowledge graph based on the official Android document. Because each permission or API in the document is described by a specific sentence, we can easily acquire and comprehend the relationship between different features via the hyperlink in sentences or sentence similarity. ArgusDroid also extracts various feature sets from the knowledge graph and validates the detection performance on Android malware family variants based on these features. Extensive experiments by using machine learning and neural network classifiers for variant identification have been carried out. The experimental results demonstrate the effectiveness and usefulness of our obtained feature sets based on ArgusDroid, especially when using the classifiers convolutional neural network(CNN) and multi-layer perception(MLP). Furthermore,when compared to similar feature sets that aim to present relationships across different feature types, such as Axplorer, ArgusDroid generates the feature set which significantly improves malware variant detection by 0.3575 average F1.

关键词： malicious behavior Android document knowledge graph malware family variant machine learning

Liquid metal fractals induced by synergistic oxidation

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Science Bulletin 2018年第22期63卷 1513-1520页

作者： sen chen Lei Wang Qinglei Zhang Jing Liu Beijing Key Laboratory of Cryo-Biomedical Engineering and Key Laboratory of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences School of Future Technology University of Chinese Academy of Sciences Department of Biomedical Engineering School of Medicine Tsinghua University

Ga-based liquid metal has drawn attention in the field of interface science due to its large ***, the spreading and shaping of liquid metal still remain a huge challenge to be solved owing to its large surface ***, an intriguing synergistic oxidation-driven liquid metal fractal phenomenon was discovered and the general mechanisms were interpreted, which provides a new strategy for manipulating liquid *** results demonstrate that the liquid metal placed on the graphite plate exhibited fractal characteristics with the addition of hydrogen ***, it is of significance that hydrogen peroxide and graphite plates synergistically oxidize liquid *** addition, we predicted that liquid metal fractals can also be achieved on other eligible substrates based on the proposed general mechanism, which was confirmed by relevant ***, the fractal dimensions of liquid metal fractal pattern were obtained and evaluated, distinguishing the synergistic oxidation-driven liquid metal fractals from the voltage-driven liquid metal ***, we initially gave the best concentration range in which dendritic fractals can occur in order to guide *** ability to achieve liquid metal fractals promises rich opportunities in freely driving the liquid metal for soft machines and manufacturing the shape-reconfigurable electronic circuits.

关键词： Liquid metal Fractal phenomenon Synergistic oxidation Spontaneous spreading Non-equilibrium thermodynamics Soft matter

On comparison of modified ADRCs for nonlinear uncertain systems with time delay

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Science China(Information Sciences) 2018年第7期61卷 212-226页

作者： sen chen Wenchao XUE Sheng ZHONG Yi HUANG Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

To tackle systems with both uncertainties and time delays, several modified active disturbance rejection control(ADRC) methods, including delayed designed ADRC(DD-ADRC), polynomial based predictive ADRC(PP-ADRC), Smith predictor based ADRC(SP-ADRC) and predictor observer based ADRC(PO-ADRC), have been proposed in the past years. This paper is aimed at rigorously investigating the performance of these modified ADRCs, such that the improvements of each method can be *** capability to tackle time delay, the necessity of stable open loop and the performance of rejecting uncertainties for these methods are fully studied and compared. It is proven that large time delay cannot be tolerated for the stability of the closed-loop systems based on DD-ADRC and PP-ADRC. Moreover, stable open loop is shown to be necessary for stabilizing the closed-loop systems based on SP-ADRC. Furthermore,the performance of rejecting the "total disturbance" at low frequency for these modified ADRCs is evaluated and quantitatively discussed. Finally, the simulations of a boiler turbine system illustrate the theoretical results.

关键词： extended state observer active disturbance rejection control uncertain system time delay predictor

A novel ADRC-based design for a kind of flexible aerocraft

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Control Theory and Technology 2021年第1期19卷 35-48页

作者： Sheng Zhong Yi Huang sen chen Lin Dai Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Mathematics and Information Science Shaanxi Normal UniversityXi'anShaanxi 710119China Beijing System Design Institute of Electro-Mechanic Engineering Bejing 100854China

The paper presents a novel control design,which is based on the idea of active disturbance rejection control(ADRC),for a kind of flexible aerocraft whose contolled variable cannot be measured *** the original frame of ADRC can-not be directly applied,the paper puts forward a new extended state observer(ESO)and the corresponding ADRC *** order to assign the poles of the closed loop system to ideal positions such that the vibration can be quickly suppressed,an elastic damping term is added into feedback *** advantages of the new ESO for fectively estimating both the rigid mode and elastic mode from the measurements are ***,the analysis on the *** relative stability and the steady state of the closed-loop system is ***,the efectiveness and robustness of the proposed ADRC are verified by simulations.

关键词： Attitude control for flexible aerocraft Active disturbance rejection control(ADRC) Extended state observer(ESO)

Porothermoelastic response of an oil sand formation subjected to injection and micro-fracturing in horizontal wells

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Petroleum Science 2020年第3期17卷 687-700页

作者： Botao Lin Han Meng Jingjun Pan sen chen State Key Laboratory of Petroleum Resources and Prospecting&College of Petroleum Engineering China University of PetroleumBeijing 102249China Oil Production Technology Research Institute PetroChina Xinjiang Oilfield CompanyKaramay 834000XinjiangChina

Stimulation of unconsolidated formations via horizontal wells has seen its vast implementation in the recent development of heavy oil reservoir to save the time and cost of preheating the reservoir before the steam-assisted gravity drainage(SAGD)process.A mathematical approach was proposed in this research that fully couples the hydraulic,mechanical and thermal responses of unconsolidated sandstone formations and also applies failure criteria for describing either shear dilation or tensile parting mechanism that generates *** approach was implemented to predict the porothermoelastic response of a pair of SAGD wells subject to injection and subsequent micro-fracturing using hot *** was found that the predicted bottom hole pressures(BHPs)match closely with the field observed *** elliptical dilation zone developed around the dual wells with relatively high pore pressure,porosity,permeability and temperature,implying good interwell hydraulic communication between both *** activation of microcracks dramatically accelerated the dissipation of pore pressure across the entire formation depth and also facilitated heat convection in between the dual wells,though to a lesser *** summary,the approach provides a convenient means to assist field engineers in the optimization of injection efficiency and evaluation of interference among multiple horizontal wells.

关键词： Porothermoelastic response Unconsolidated sandstone Injection Micro-fracturing Microcracks Oil sand

NUMERICAL SIMULATION FOR 2D SHALLOW WATER EQUATIONS BY USING GODUNOV-TYPE SCHEME WITH UNSTRUCTURED MESH

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Journal of Hydrodynamics 2006年第4期18卷 475-480页

作者： PAN Cun-hong DAI Shi-qiang chen sen-mei Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200436 China Zhejiang Institute of Hydraulics and Estuary Hangzhou 310020 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University. Shanghai 200436 China Zhejiang Institute of Hydraulics and Estuary Hangzhou 310020. China

In order to establish a well-balanced scheme, 2D shallow water equations were transformed and solved by using the Finite Volume Method （FVM） with unstructured mesh. The numerical flux from the interface between cells was computed with an exact Riemann solver, and the improved dry Riemann solver was applied to deal with the wet/dry problems. The model was verified through computing some typical examples and the tidal bore on the Qiantang River. The results show that the scheme is robust and accurate, and could be applied extensively to engineering problems.

关键词： 2D shallow water equations Finite Volume Method (FVM) unstructured mesh Godunov-type scheme Riemann solver

A cortical bone milling force model based on orthogonal cutting distribution method

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Advances in Manufacturing 2020年第2期8卷 204-215页

作者： Qi-sen chen Li Dai Yu Liu Qiu-Xiang Shi School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819People's Republic of China

In orthopedic surgery,the bone milling force has attracted attention owing to its significant influence on bone cracks and the breaking of *** is necessary to build a milling force model to improve the process of bone *** paper proposes a cortical bone milling force model based on the orthogonal cutting distribution method(OCDM),explaining the effect of anisotropic bone materials on milling *** to the model,the bone milling force could be represented by the equivalent effect of a transient cutting force in a rotating period,and the transient milling force could be calculated by the transient milling force coefficients,cutting thickness,and cutting *** on the OCDM,the change in transient cutting force coefficients during slotting can be described by using a quadratic ***,the force model is updated for robotic bone milling,considering the low stiffness of the robot ***,an experimental platform for robotic bone milling is built to simulate the milling process in clinical operation,and the machining signal is employed to calculate the milling ***,according to the experimental result,the rationality of the force model is verified by the contrast between the measured and predicted *** milling force model can satisfy the accuracy requirement for predicting the milling force in the different processing directions,and it could promote the development of force control in orthopedic surgery.

关键词： Robotic milling force Cortical bone Cutting force coefficient Orthogonal cutting distribution