• Volume 12,Issue 3,2020 Table of Contents
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    • A survey of image feature detection and matching methods

      2020, 12(3):261-273. DOI: 10.13878/j.cnki.jnuist.2020.03.001

      Abstract (501) HTML (0) PDF 4.25 M (2068) Comment (0) Favorites

      Abstract:For decades,image feature detection and matching has been the foundation of computer vision.Without feature detection and matching,there would be no visual tasks such as SLAM,Sfm,AR,image retrieval,image registration,or panoramic images.Based on the review of classic detection algorithms in the past decades,this paper describes the latest progress in image feature detection and matching after the introduction of machine learning algorithm led by deep learning.The survey includes all the key points such as feature points,local descriptor,global descriptor,matching and optimization,and end-to-end framework,and compares the merits and demerits of each algorithm.In summary,facing the requirements of wide baseline,real-time,and low computing load detection from the industrial sector,image feature detection and matching is still a hard task.The multitasking global framework which fuses feature points,local descriptor,global descriptor,matching and optimization has become the trend of future research.

    • Survey of video summary

      2020, 12(3):274-278. DOI: 10.13878/j.cnki.jnuist.2020.03.002

      Abstract (450) HTML (0) PDF 903.55 K (2347) Comment (0) Favorites

      Abstract:Recently,with the development of computer technology and the widespread use of terminal equipment,video summary technology has been extensively studied,which is an important research direction of data summary.This paper introduces the latest research progress of video summary.Firstly,the basic concepts of static video summary are introduced,and then the latest research progress on the convex relaxation method and determinant point process method of static video summary is surveyed.For dynamic video summaries,the most recent research advances in segmented and personalized video summaries are introduced.Finally,the problems facing the video summary and future research directions are introduced.

    • Observer-based output feedback control for networked control systems under denial-of-service attacks

      2020, 12(3):279-283. DOI: 10.13878/j.cnki.jnuist.2020.03.003

      Abstract (334) HTML (0) PDF 1011.63 K (1776) Comment (0) Favorites

      Abstract:This paper is concerned with H output feedback control problem of networked control systems under denial-of-service attacks.Denial-of-service attacks are characterized by energy constraint jamming signal with periodic strategy,which attack wireless network channels and degrade system performance.Under the premise that the state of the system is partly unknown,by designing the observer-based output feedback controller,networked control systems under packet loss and denial-of-service attacks can maintain stable and pre-specified performance level.Finally,a numerical example is presented to verify the effectiveness of the designed controller.

    • Multiple attribute intuitionistic fuzzy tolerance rough set models

      2020, 12(3):284-288. DOI: 10.13878/j.cnki.jnuist.2020.03.004

      Abstract (347) HTML (0) PDF 882.87 K (1740) Comment (0) Favorites

      Abstract:This paper proposes the intuitionistic fuzzy rough set models based on tolerance relation in intuitionistic fuzzy information system,in which the target concept is described from two aspects of optimistic and pessimistic,which is a new approximation method for target concept.In addition,some relationship is found between optimistic and pessimistic approximations.The approximate accuracy of optimistic intuitionistic fuzzy tolerance rough set is higher than that that of the pessimistic one according to the definition of approximation accuracy.Finally,the empirical analysis is provided,which verifies the effectiveness of the presented method.

    • Attitude control strategy of heterogeneous spacecraft based on saturation constraint and time-varying observer design

      2020, 12(3):289-297. DOI: 10.13878/j.cnki.jnuist.2020.03.005

      Abstract (318) HTML (0) PDF 2.98 M (1676) Comment (0) Favorites

      Abstract:In order to solve the problems of the nonlinear and uncertain effects in the heterogeneous space environment,the actuator input saturation constraint,and the difficulty of collaborative scheduling with limited resources in attitude control of multiple heterogeneous spacecraft,a robust consistent tracking control strategy with saturated input and uncertain dynamics for heterogeneous spacecraft is proposed.In the proposed control strategy,the dynamic weight matrix of the reference system is allowed to be completely unknown,so the existing method has no feasible solution.By introducing the directed spanning tree assumption,a new weighted averaging method is proposed to construct the distributed observer dynamics.Then,a new class of robust consensus tracking controllers is designed by combining distributed observations with nonlinear dynamics.The simulation results show that when synchronous behavior and distributed observation dynamics can be obtained simultaneously and to reach the leader state,the problem of robust consistency of heterogeneous systems will be solved.At the same time,using the dynamic model of heterogeneous spacecraft,the parameter conditions of different performance indexes are designed,and the effectiveness of the proposed method is verified and analyzed.

    • Robust fault detection filter for spacecraft autonomous rendezvous via delta operator method

      2020, 12(3):298-304. DOI: 10.13878/j.cnki.jnuist.2020.03.006

      Abstract (357) HTML (0) PDF 1.67 M (1749) Comment (0) Favorites

      Abstract:This paper addresses the robust fault detection problem for spacecraft autonomous rendezvous with digital communication constraints.The Clohessy-Wiltshire equation is employed to describe the relative dynamic model,and the discrete-time model with sampling behavior is proposed by using delta operator approach.In this design,the data are exchanged among components of spacecraft,and signal quantization and data packet losses are considered in a unified framework.The stochastic variables with Bernoulli random binary distribution are utilized to describe the random rate dropout.A sufficient condition for the existence of the designed fault detection filter is presented with linear matrix inequalities techniques.Finally,a practical example is illustrated to demonstrate the effectiveness of the proposed fault detection techniques.

    • Fuzzy-model-based H consensus tracking control of multi-agent systems

      2020, 12(3):305-310. DOI: 10.13878/j.cnki.jnuist.2020.03.007

      Abstract (621) HTML (0) PDF 1.17 M (1662) Comment (0) Favorites

      Abstract:This paper is concerned with the H consensus problem for nonlinear leader-follower multi-agent systems (MASs) with a directed communication network.A polynomial fuzzy modeling approach is proposed to describe the error system which is formulated by leader and follower agents.Then,the consensus control protocols are designed for MASs to enforce all the followers to track the trajectory of a leader asymptotically.Based on the polynomial Lyapunov function method,sufficient conditions are presented to ensure the consensus for MASs subject to external disturbances.The obtained conditions are converted into sum of squares and can be numerically solved.Finally,a simulation example is provided to demonstrate the effectiveness of the derived theoretical results.

    • Response time measurement of photoelectric detection system based on diode laser

      2020, 12(3):311-315. DOI: 10.13878/j.cnki.jnuist.2020.03.008

      Abstract (375) HTML (0) PDF 1.78 M (1997) Comment (0) Favorites

      Abstract:Photoelectric detection system is the core component of a detector,and is widely used in photo-metric measurement and spectroscopy monitoring.Response time of a photoelectric detection system reflects the fastest response limit of the system in detection.Thus,an accurate measurement of the response time is very important for application.This work shows a method for accurate response time measurement of a photoelectric detection system.Here,a tunable diode laser with a wavelength of 763 nm,usually used in spectroscopy,is used as the light source and is tuned with a square wave.The response time is measured.The results indicates that the resistance of the oscilloscope can influence the response time of the system.The response time of the photoelectric detection system is measured as 4.5 μs when the resistance value is 50 Ω.The response time can be shortened if the resistance value reduces.This work provides a response time measurement method of a photoelectric detection system,which is a basis for the choice of detection system in application.

    • State constraints-based finite-time position tracking control for DC motor

      2020, 12(3):316-321. DOI: 10.13878/j.cnki.jnuist.2020.03.009

      Abstract (280) HTML (0) PDF 997.82 K (1569) Comment (0) Favorites

      Abstract:A neural networks-based adaptive finite-time position tracking control method for DC motor with state constraints is proposed in this paper.Firstly,the barrier Lyapunov function (BLF) is introduced to constrain the state variables of DC motor,which ensures that the angular position and angular speed of motor are limited within the given constraint range,the neural networks are used to approximate unknown nonlinear functions in the system.In addition,the finite-time control technology is introduced to improve response speed and convergence speed of the system.The simulation results show that the control method can achieve fast and effective tracking control of DC motor.

    • Flocking towards a robust mobile network topology

      2020, 12(3):322-329. DOI: 10.13878/j.cnki.jnuist.2020.03.010

      Abstract (323) HTML (0) PDF 2.88 M (1604) Comment (0) Favorites

      Abstract:This paper proposes methods to improve the topology robustness and connection robustness against jittering from both mobile bases and network users of mobile networks in a 2D space under limited sensing ranges.The control strategy is assumed to be asynchronous due to the unsynchronized dynamics of the mobile bases and the users in the network.The conditions are derived based on redefined connection based on enclosed areas to maintain the current network topology,and two methods are designed to ensure that the conditions are satisfied in the course of improving topology and connection robustness.Then,a combined method is devised,and the sufficient condition is presented such that the network topology remain intact.Finally,numerical examples are presented to test the performance of the proposed techniques.

    • Adaptive finite-time dynamic surface control for nonlinear systems with input quantization and unknown disturbances

      2020, 12(3):330-340. DOI: 10.13878/j.cnki.jnuist.2020.03.011

      Abstract (368) HTML (0) PDF 1.31 M (1734) Comment (0) Favorites

      Abstract:In this paper,the problem of finite-time adaptive output feedback dynamic surface control is studied for a class of nonlinear systems with quantized input signals and unknown disturbances.In the control design process,the nonlinear terms in the system are approximated by the fuzzy logic systems.A hysteretic quantizer is introduced to avoid chattering in the quantized signals,and the fuzzy state observer is constructed to estimate the unmeasurable states of the system.In order to propose the finite-time control strategy,firstly,a semi-global practical finite-time stability criterion is given.On this basis,an adaptive fuzzy controller is designed by combining the dynamic surface control technology with backstepping method.The controller can not only ensure that the observer and tracking error converge to a small neighborhood of the origin in a finite time,but also keep all the signals in the closed-loop system bounded.Finally,a simulation example is given to verify the effectiveness and feasibility of the control method.

    • Denauit-Hartenbery based image design and control method of high resolution Kirkpatrick-Baez mirror

      2020, 12(3):341-346. DOI: 10.13878/j.cnki.jnuist.2020.03.012

      Abstract (505) HTML (0) PDF 3.14 M (1749) Comment (0) Favorites

      Abstract:In view of the difficult situation of Kirkpatrick-Baez (KB) high-resolution micro-control in high-energy plasma X-ray diagnosis,a new method of realizing high-resolution micro-control based on Denauit-Hartenbery (DH) coordinate system is proposed.In this structure,the front and rear lenses of the KB microscope are used as the rigid manipulator with double 5 degrees of freedom(DOF) respectively to realize the control of the double 5-DOF.The new method is modeled theoretically and the kinematic equations of each linkage coordinate system and structure of the two manipulators are analyzed.The optical system of the double 5-DOF manipulator is built,and the proposed KB mirror control method is verified by experiments.The experimental results show that the double 5-DOF manipulator designed can realize the precise control of the KB mirror and obtain high precision resolution imaging effect.

    • Image recovery and clustering approach based on weighted Manhattan non-negative matrix factorization

      2020, 12(3):347-352. DOI: 10.13878/j.cnki.jnuist.2020.03.013

      Abstract (305) HTML (0) PDF 1.50 M (1626) Comment (0) Favorites

      Abstract:Traditional robust non-negative matrix factorization methods cannot achieve robust low-dimensional features while the data is heavily contaminated by Salt and Pepper noise.To address this issue,this paper proposes a more robust weighted Manhattan non-negative matrix factorization to recover the contaminated data and obtain robust part-based representations.Our proposed model can be formulated as a non-convex and non-smooth problem,which can be solved by the accelerated gradient method and the rank-one-residual-iteration method.Experiments on the ORL face dataset contaminated by Salt and Pepper noise demonstrate that our proposed algorithm is more effective and robust in image recovery and feature representation learning.

    • Networked predictive control of the distributed sensor networks

      2020, 12(3):353-359. DOI: 10.13878/j.cnki.jnuist.2020.03.014

      Abstract (366) HTML (0) PDF 5.04 M (1608) Comment (0) Favorites

      Abstract:This paper is concerned with the networked predictive controller design problem for the distributed sensor network represented by the well-known discrete-time two-dimensional (2-D) Fornasini-Marchesini (FM) state-space model.Particularly,a novel networked predictive control (NPC) scheme is employed for the considered 2-D distributed sensor networks in order to compensate for the communication delay actively.Firstly,by using the Lyapunov stability theory,sufficient conditions are established for such distributed sensor networks.Based on the stability analysis results,a new predictive controller design strategy is proposed to stabilize the addressed systems and also achieve the desired control performance.Finally,an example is given to demonstrate the effectiveness of the newly developed NPC strategy for the distributed sensor networks.

    • Convergence of sparse coding based on KKT conditions

      2020, 12(3):360-363. DOI: 10.13878/j.cnki.jnuist.2020.03.015

      Abstract (321) HTML (0) PDF 1.23 M (1538) Comment (0) Favorites

      Abstract:This paper proposes a sparse coding algorithm based on KKT conditions.Firstly,the non-convex non-smooth sparse coding problem is decomposed into two convex non-smooth problems.Secondly,the two convex non-smooth problems are skillfully transformed into three smooth convex optimization problems by using two matrices.Finally,the three problems are solved by KKT conditions.In addition,we prove the convergence of the algorithm.Meanwhile,experimental simulation shows the convergence of the algorithm.

    • Quantitative assessment and analysis on the prevention-control measures of COVID-19 based on staged transmission model

      2020, 12(3):364-372. DOI: 10.13878/j.cnki.jnuist.2020.03.016

      Abstract (467) HTML (0) PDF 3.04 M (1691) Comment (0) Favorites

      Abstract:A staged transmission model for Corona Virus Disease 2019 (COVID-19) was built based on virus infection dynamics considering prevention and control measures during different periods.The whole country is classified into three level of epidemic areas according to the seriousness of COVID-19,and the number of infected people in each epidemic area is simulated in a staged way.Based on analysis of the simulation results,the impact of measures taken in each epidemic area,such as the traffic control in Wuhan,the counterpart support to Hubei,and the closed community management,on the suppression of virus transmission was further evaluated.The results show that the staged transmission model can well model the changing characteristics of the number of infected people during different periods in each epidemic area.The prevention and control measures practiced by government,such as the traffic control in Wuhan and the closed community management,have significantly inhibited the spreading of COVID-19,indicated by the substantial downward trend in the number of infected people.

    • Big data analysis of cloud-to-ground lightning in Jinqu Basin during 2007-2018

      2020, 12(3):373-383. DOI: 10.13878/j.cnki.jnuist.2020.03.017

      Abstract (460) HTML (0) PDF 15.20 M (1562) Comment (0) Favorites

      Abstract:Based on the cloud-to-ground (CG) lightning data in Jinhua area from 2007 to 2018,we analyzed the climatic characteristics of CG lightning in Jinqu Basin and the corresponding relationship between CG lightning and topography or altitude.The results showed that:(1) The annual average times of lightning in Jinhua area from 2007 to 2018 is 45 481,and the average annual CG lightning density is 4.3 fl·km-2·a-1,which varies from 2.64 to 5.92 fl·km-2·a-1;(2)The difference in spatial distribution of annual CG lightning in Jinhua is rather big,and the CG lightning mainly occurred in the southwestern corner of Jinhua,specifically in Xianxia ridge area and along the Kuaiji mountain,as well as the Jinhua mountain at the junction of Lanxi city,Wucheng district and Jindong district.While in the southeast corner of Dapan mountain and in the north area of Longmen mountain,the total CG lightning density is relatively small;(3) Total CG lightning density has certain relation with topography and altitude.When the total flash density is above 80 times·km-2,it probably distributed in high-altitude mountainous areas;and 23 points out of the 25 points with strong lightning density (5-7 fl·km-2) distributed in the mountainous areas between 208 m and 989 m above sea level;(4) The CG lightning density in the Sanjiang River basin is the lowest,and it is barely close to the average along the Hangzhou-Changsha Railway and in its vicinity,which is inconsistent with other relevant research conclusions;(5) During the 12 years of 2007-2018,the number and total number of CG lightning increased with altitude in 41.7% years,and in the rest of 58.3% years,the average and total average CG lightning intensity increased with altitude,both of which have passed the significant test.

    • Six degree-of-freedom self-balancing platform design based on EtherCAT

      2020, 12(3):384-389. DOI: 10.13878/j.cnki.jnuist.2020.03.018

      Abstract (315) HTML (0) PDF 4.27 M (3622) Comment (0) Favorites

      Abstract:In order to solve the problem of slow response and low control precision for the traditional self-balancing platform,a six degree-of-freedom self-balancing platform is designed based on EtherCAT bus.Six servo drivers that support EtherCAT communication drive six electric cylinders to stretch contraction.The inclination data of the platform is read by the gyroscope and transmitted to the main station through EtherCAT.And the platform is accurately controlled by using the active disturbance rejection control (ADRC) algorithm.Experimental results show that the designed platform has the advantages of low latency and high anti-interference ability.

    • Spatial and temporal distribution of meteorological early warning signals released by Hubei province during 2016-2019

      2020, 12(3):390-394. DOI: 10.13878/j.cnki.jnuist.2020.03.019

      Abstract (369) HTML (0) PDF 932.85 K (1598) Comment (0) Favorites

      Abstract:A study into the space-time characteristics of meteorological early warning signalshave significance to extreme weather events monitoring and climatic disaster emergency management.The meteorological early warning signalsreleased by Hubei province during the period of 2016-2019 were statistically analyzed in classification of signal category,disastergrade,releasing date,and covered area.It is found that torrential rain,strong wind,thunder & lightning,heavy fog,and heat wave were listed as the main warning events,and mainly targeted at southeast and southwest of Hubei during July-August.The principles for releasing meteorological early warning signals are summarized for Hubei province.


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