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Dual tree complex wavelet transform approach to copy-rotate-move forgery detection

science China(Information sciences) 2014年第1期57卷 125-136页

作者： WU YunJie DENG Yu DUAN HaiBin ZHOU LinNa Science and Technology on Aircraft Control Laboratory BeiHang University Department of Electronics Engineering Tsinghua University

As a common scheme of image tampering,copy-move forgery plays an important role in image forgery *** several blind methods aimed at detecting replicated regions have been proposed,these methods cannot detect the rotation changes in the duplicated areas *** this paper,a new forensic method is presented to detect the replicated areas rotated by arbitrary angles,even by JPEG *** achieve this,overlapping blocks of pixels are decomposed using dual tree complex wavelet transform(DTCWT),and then channel energies are extracted from each subband at each decomposition level using the ***,the anisotropic rotationally invariant features are extracted using magnitudes of discrete Fourier transform for these channel *** implementation procedure of the proposed method is described in *** experimental results,including a comparative evaluation with existing methods and the special applications in practice,are also presented to demonstrate the robustness and efectiveness of the proposed method.

关键词： digital image forgery digital image forensic copy-rotate-move forgery dual tree complex wavelet transform

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A Quantum-behaved Pigeon-Inspired Optimization approach to Explicit Nonlinear Model Predictive controller for quadrotor

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International Journal of Intelligent Computing and Cybernetics 2018年第1期11卷 47-63页

作者： Ning Xian Zhilong Chen Science and Technology on Aircraft Control Laboratory Beihang University(BUAA)BeijingChina

Purpose–The purpose of this paper is to simplify the Explicit Nonlinear Model Predictive controller(ENMPC)by linearizing the trajectory with Quantum-behaved Pigeon-Inspired Optimization(QPIO).Design/methodology/approach–The paper deduces the nonlinear model of the quadrotor and uses the ENMPC to track the *** the ENMPC has high demand for the state equation,the trajectory needed to be differentiated many *** the trajectory is complicate or discontinuous,QPIO is proposed to linearize the *** the linearized trajectory will be used in the ***–Applying the QPIO algorithm allows the unequal distance sample points to be acquired to linearize the *** with the equidistant linear interpolation,the linear interpolation error will be *** implications–Small-sized quadrotors were adopted in this research to simplify the *** model is supposed to be accurate and differentiable to meet the requirements of ***/value–Traditionally,the quadrotor model was usually linearized in the *** this paper,the quadrotormodel waskept nonlinear and the trajectorywill be *** sample points were utilized to linearize the *** this way,the authors can get a smaller interpolation *** method can also be applied to discrete systems to construct the interpolation for trajectory tracking.

关键词： Explicit Nonlinear Model Predictive controller Linearized trajectory Quantum-behaved Pigeon-Inspired Optimization

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Sliding mode disturbance observer-based backstepping control for a transport aircraft

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science China(Information sciences) 2014年第5期57卷 228-243页

作者： ZHANG Chao CHEN ZongJi WEI Chen Science and Technology on Aircraft Control Laboratory Beihang University School of Automation Science and Electrical Engineering Beihang University

This paper presents a novel control method by integrating the sliding mode disturbance observerbased control and the backstepping control technique,and successfully applies it to a flight control system for heavy cargo airdrop *** super-twisting second order sliding mode disturbance observer(SOSMDO)is employed to estimate bounded but otherwise arbitrary disturbances,thus ensuring asymptotic convergence of the estimation error to zero in a finite ***,the integrated controller can significantly improve the robustness of the flight control system to modeling uncertainty and external disturbance in the presence of state/control *** closed-loop stability is guaranteed in the sense of *** addition,the proposed approach can considerably reduce design *** performance of the proposed control method is demonstrated in a very low altitude extraction airdrop simulation with a high-fidelity six-degree-of-freedom transport aircraft model.

关键词： backstepping sliding mode disturbance observer flight control heavy cargo airdrop uncertainty estimation

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A modified segmentation approach for synthetic aperture radar images on level set

Journal of Software

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Journal of Software 2013年第5期8卷 1168-1173页

作者： Peng, Qiangqiang Long, Zhao Science and Technology on Aircraft Control Laboratory Beihang University Beijing 100191 China

In this paper, we propose a method towards unsupervised segmentation of synthetic aperture radar (SAR) image for segmentation of homogeneous regions. The SAR amplitude image is modeled by Rayleigh distribution. Moreover, in order to avoid geometric topology variations, the curve evolution is implemented via level sets. In addition, a new energy function is proposed, which is more objective and robust for the segmentation purpose. During the curve evolution, a convex factor is considered to guarantee the regularity of the region boundary. Finally, a novel termination criterion of the evolution of energy function is designed. And then, the effectiveness of our method is demonstrated on real SAR images. © 2013 Academy Publisher.

关键词： Synthetic aperture radar

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Parameters identification of UCAV flight control system based on predator-prey particle swarm optimization

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science China(Information sciences) 2013年第1期56卷 121-132页

作者： DUAN HaiBin YU YaXiang ZHAO ZhenYu Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical EngineeringBeihang University

With the improvement of the aircraft flight performance and development of computing science,uninhabited combat aerial vehicle(UCAV) could accomplish more complex *** this also put forward stricter requirements for the flight control system,which are the crucial issues of the whole UCAV system *** paper proposes a novel UCAV flight controller parameters identification method,which is based on predator-prey particle swarm optimization(PSO) algorithm.A series of comparative experimental results verify the feasibility and effectiveness of our proposed approach in this paper,and a predator-prey PSO-based software platform for UCAV controller design is also developed.

关键词： uninhabited combat aerial vehicle(UCAV) particle swarm optimization(PSO) parameters identification predator-prey

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Entropy optimization based filtering for non-Gaussian stochastic systems

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science China(Information sciences) 2017年第12期60卷 33-43页

作者： Bo TIAN Yan WANG Lei GUO School of Automation Science and Electrical Engineering Beihang University National Key Laboratory on Aircraft Control Technology Beihang University

This paper is concerned with the entropy optimization based filter design for a class of multivariate dynamic stochastic systems with simultaneous presence of non-Gaussian process noise and measurement *** filter consists of time update and measurement update two steps, where the selection of the filter gain in the measurement update equation is a key issue to be addressed. Different from the classic Kalman filter theory, entropy rather than variance is employed as the filtering performance criterion due to the non-Gaussian characteristic of the estimation error. Following the establishment of the relationship between the probability density functions of random noises and estimation error, two kinds of entropy based performance indices are provided. On this basis, the corresponding optimal filter gains are obtained respectively by using the gradient optimization technique. Finally, some numerical simulations are provided to demonstrate the effectiveness of the proposed filtering algorithms.

关键词： non-Gaussian systems joint probability density function(JPDF) quadratic information potential relative entropy optimal filtering

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Lightweight hybrid visual-inertial odometry with closed-form zero velocity update

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Chinese Journal of Aeronautics 2020年第12期33卷 3344-3359页

作者： QIU Xiaochen ZHANG Hai FU Wenxing School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on Aircraft Control Laboratory Beijing 100191China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing 100074China

Visual-Inertial Odometry(VIO) fuses measurements from camera and Inertial Measurement Unit(IMU) to achieve accumulative performance that is better than using individual *** VIO is an extended Kalman filter-based solution which augments features with long tracking length into the state vector of Multi-State Constraint Kalman Filter(MSCKF). In this paper, a novel hybrid VIO is proposed, which focuses on utilizing low-cost sensors while also considering both the computational efficiency and positioning precision. The proposed algorithm introduces several novel contributions. Firstly, by deducing an analytical error transition equation, onedimensional inverse depth parametrization is utilized to parametrize the augmented feature *** modification is shown to significantly improve the computational efficiency and numerical robustness, as a result achieving higher precision. Secondly, for better handling of the static scene,a novel closed-form Zero velocity UPda Te(ZUPT) method is proposed. ZUPT is modeled as a measurement update for the filter rather than forbidding propagation roughly, which has the advantage of correcting the overall state through correlation in the filter covariance matrix. Furthermore, online spatial and temporal calibration is also incorporated. Experiments are conducted on both public dataset and real data. The results demonstrate the effectiveness of the proposed solution by showing that its performance is better than the baseline and the state-of-the-art algorithms in terms of both efficiency and precision. A related software is open-sourced to benefit the community.

关键词： Inverse depth parametrization Kalman filter Online calibration Visual-inertial odometry Zero velocity update

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Lateral Reentry Guidance for Maneuver Glide Vehicles with Geographic Constraints

Lateral Reentry Guidance for Maneuver Glide Vehicles with Ge...

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第三十二届中国控制会议

作者： LIANG Zixuan REN Zhang BAI Chen Science and Technology on Aircraft Control Laboratory Beihang University

ISBN: (纸本)9789881563835

A new lateral reentry guidance method for maneuver glide vehicles is presented specially to satisfy the geographic *** entry trajectory constraints including the common path constraints and the geographic constraints are considered,and a guidance strategy is *** conventional linear quadratic regulator(LQR) is used to track the longitudinal profiles.A lateral guidance algorithm based on target prediction is studied for the mission of matching waypoints. With the target's cross range error,the reversal logic and fine adjustment method of bank angle are *** to the mission of avoiding no-fly zones,a lateral guidance algorithm with on-line designed dynamic heading error corridor is presented Simulation in nominal case indicates that the geographic and other constraints can be satisfied with only 5 bank *** Monte Carlo simulations are taken for the distribution of initial condition and aerodynamic *** lateral guidance provides good performance cooperated with the longitudinal guidance,and has a perfect interference capacity for the disturbance.

关键词： Reentry guidance glide vehicles geographic constraints waypoint no-fly zone

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Optimization Studies of Weight Matrix in LQR for Reentry Vehicle Profile-following 33

Optimization Studies of Weight Matrix in LQR for Reentry Veh...

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第三十三届中国控制会议

作者： XIONG Zihao REN Zhang LIANG Zixuan BAI Chen Science and Technology on Aircraft Control Laboratory Beihang University

ISBN: (纸本)9781479947249

Because of particular dynamic characteristics,the traditional method for calculating weight matrices in LQR is not suitable for reentry vehicle *** paper designs parameter varying weight *** this method,on the basis of vehicle entry flight characteristics,we design the functional relationship between weight matrix parameters and flight *** simulations show that this method can improve the performance of reentry vehicle profile following obviously,and it is more robust to different disturbances.

关键词： Reentry vehicle profile following LQR weight matrix optimization

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Inductive Monitoring System Based Fault Detection for Liquid-Propellant Rocket Engines 34

Inductive Monitoring System Based Fault Detection for Liquid...

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第三十四届中国控制会议

作者： GAO Kehan XIONG Zihao YI Ke DONG Xiwang YANG Peng LI Qingdong REN Zhang Science and Technology on Aircraft Control Laboratory Beihang University

ISBN: (纸本)9789881563897

The ability of in-time,real-time and reliable fault detection is essential for liquid-propellant rocket engine to monitor its working *** Monitoring System(IMS) is a data-mining based real-time fault detection *** paper studies the problem that how to reduce the high false alarm rate when IMS is applied to monitor the system during trials or *** is found that the order of sample data and outliers of test data contribute a lot to the high false alarm *** reduce the interference evoked by the order of sample data and outliers of test data,an improved IMS method is proposed by rescheduling the sample data and processing outliers that may occur during the monitoring *** is performed to show that the improved IMS in this paper can decrease the false alarm rate while ensuring timeliness,reliability and accuracy of fault detection.

关键词： Liquid-propellant rocket engine fault detection Inductive Monitoring System

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