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A novel four-wing chaotic attractor generated from a three-dimensional quadratic autonomous system

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Chinese Physics B 2009年第7期18卷 2680-2689页

作者：董恩增陈在平陈增强袁祉 Department of automation Tianjin University of Technology Department of automation Nankai University

This paper presents a new 3D quadratic autonomous chaotic system which contains five system parameters and three quadratic cross-product terms,and the system can generate a single four-wing chaotic attractor with wide parameter ranges. Through theoretical analysis,the Hopf bifurcation processes are proved to arise at certain equilibrium *** bifurcation analysis shows that the system has many interesting complex dynamical behaviours;the system trajectory can evolve to a chaotic attractor from a periodic orbit or a fixed point as the proper parameter varies. Finally,an analog electronic circuit is designed to physically realize the chaotic system;the existence of four-wing chaotic attractor is verified by the analog circuit realization.

关键词： chaos four-wing chaotic attractor bifurcation analysis chaotic circuit

Feasibility analysis and online adjustment of constraints in model predictive control integrated with soft sensor

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Chinese Journal of Chemical Engineering 2017年第9期25卷 1230-1237页

作者： Pengfei Cao Xionglin Luo Xiaohong Song College of Electrical Engineering and automation Shandong University of Science and Technology research inst.tute of automation China University of Petroleum State Grid Shandong Electric Power Company Zibo Power Supply Company

Feasibility analysis of soft constraints for input and output variables is critical for model predictive control(MPC).When encountering the infeasible situation, some way should be found to adjust the constraints to guarantee that the optimal control law exists. For MPC integrated with soft sensor, considering the soft constraints for critical variables additionally makes it more complicated and difficult for feasibility analysis and constraint adjustment. Therefore, the main contributions are that a linear programming approach is proposed for feasibility analysis, and the corresponding constraint adjustment method and procedure are given as well. The feasibility analysis gives considerations to the manipulated, secondary and critical variables, and the increment of manipulated variables as well. The feasibility analysis and the constraint adjustment are conducted in the entire control process and guarantee the existence of optimal control. In final, a simulation case confirms the contributions in this paper.

关键词： Soft sensor Model predictive control Variable constraints Feasibility analysis

Pitchfork bifurcation and circuit implementation of a novel Chen hyper-chaotic system

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Chinese Physics B 2012年第3期21卷 92-100页

作者：董恩增陈增强陈在平倪建云 Department of automation Nankai University Department of automation Tianjin University of Technology

In this paper, a novel four dimensional hyper-chaotic system is coined based on the Chen system, which contains two quadratic terms and five system parameters. The proposed system can generate a hyper-chaotic attractor in wide parameters regions. By using the center manifold theorem and the local bifurcation theory, a pitchfork bifurcation is demonstrated to arise at the zero equilibrium point. Numerical analysis demonstrates that the hyper-cha^tic system can generate complex dynamical behaviors, e.g., a direct transition from quasi-periodic behavior to hyper-chaotic behavior. Finally, an electronic circuit is designed to implement the hyper-chaotic system, the experimental results are consist with the numerical simulations, which verifies the existence of the hyper-chaotic attractor. Due to the complex dynamic behaviors, this new hyper-cha^tic system is useful in the secure communication.

关键词： hyper-chaos Chen system pitchfork bifurcation center manifold theorem

Delay Compensation of Neutral-Type Time-Delay Control Systems by Cascaded-Observers

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Journal of Systems Science & Complexity 2023年第3期36卷 1053-1069页

作者： LIU Qingsong Engineering research Center of Metallurgical automation and Measurement Technology Wuhan University of Science and TechnologyWuhan 430081China

This paper is concerned with the input delay compensation problem for neutral-type systems with both state and input ***/various cascaded-observers based output feedback controllers are designed to predict the future states such that the input delay that can be arbitrarily large yet exactly known is compensated *** with the existing techniques,some more simple necessary and sufficient conditions guaranteeing the stability of the closed-loop systems are offered in terms of the stability of retarded-type time-delay systems referred to as observer-error ***,the lossless transmission line control system is worked out to illustrate the effectiveness of the proposed controllers.

关键词： Cascaded-observers input delay compensation neutral-type time-delay systems stabilization state and input delays

Stability Analysis for Recurrent Neural Networks with Time-varying Delay

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International Journal of automation and computing 2009年第3期6卷 223-227页

作者： Yuan-Yuan Wu Yu-Qiang Wu School of automation Southeast University Nanjing 210096 PRC research inst.tute of automation Qufu Normal University Qufu 273165 PRC

This paper is concerned with the stability analysis for static recurrent neural networks （RNNs） with time-varying delay. By Lyapunov functional method and linear matrix inequality technique, some new delay-dependent conditions are established to ensure the asymptotic stability of the neural network. Expressed in linear matrix inequalities （LMIs）, the proposed delay-dependent stability conditions can be checked using the recently developed algorithms. A numerical example is given to show that the obtained conditions can provide less conservative results than some existing ones.

关键词： Static neural networks time-varying delay asymptotical stability delay-dependent linear matrix inequalities (LMIs).

Experimental study on electrical resistivity measurement of a specimen at high temperature

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Chinese Optics Letters 2009年第7期7卷 585-589页

作者：辛春锁戴景民何小瓦 Department of automation Measurement and Control Harbin Institute of Technology Aerospace research inst.tute of Materials and Processing Technology

A new technique is developed to measure the electrical resistivity of conductor with a nonuniform tem- perature profile. The calculation method is derived from the temperature dependence of the electrical resistivity. The apparatus consists mainly of a high temperature environmental chamber, a power circuit of heating, a twenty-wavelength pyrometer, and a scanning pyrometer. After getting the resistance from the voltage drop of the specimen, the electrical resistivity in a wide temperature range of the specimen can be obtained by our calculation model. Preliminary results of the electrical resistivity of SRM 8424 over a wide temperature range （1000-3000 K） are presented. The perfect consistency between the measurement results and the nominal values justifies the validity of this technique.

关键词： Electromagnetic wave emission Environmental chambers Heating Pyrometers Pyrometry

3D Profile Filter Algorithm Based on Parallel Generalized B-spline Approximating Gaussian

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Chinese Journal of Mechanical Engineering 2015年第1期28卷 148-154页

作者： REN Zhiying GAO Chenghui SHEN Ding School of Mechanical Engineering and automation Fuzhou University Tribology research inst.tute Fuzhou University Fujian inst.tute of Metrology

Currently, the approximation methods of the Gaussian filter by some other spline filters have been developed. However, thesc methods are only suitable for the study of one-dimensional filtering, when these methods are used for three-dimensional filtering, it is found that a rounding error and quantization error would be passed to the next in every part. In this paper, a new and high-precision implementation approach for Gaussian filter is described, which is suitable for three-dimensional reference filtering. Based on the theory of generalized B-spline function and the variational principle, the transmission characteristics of a digital filter can be changed through the sensitivity of the parameters （t1, t2）, and which can also reduce the rounding error and quantization error by the filter in a parallel form inst.ad of the cascade form, Finally, the approximation filter of Gaussian filter is obtained. In order to verify the feasibility of the new algorithm, the reference extraction of the conventional methods are also used and compared. The experiments are conducted on the measured optical surface, and the results show that the total calculation by the new algorithm only requires 0.07 s for 480×480 data points; the amplitude deviation between the reference of the parallel form filter and the Gaussian filter is smaller; the new method is closer to the characteristic of the Gaussian filter through the analysis of three-dimensional roughness parameters, comparing with the cascade generalized B-spline approximating Gaussian. So the new algorithm is also efficient and accurate for the implementation of Gaussian filter in the application of surface roughness measurement.

关键词： generalized B-spline Gaussian filter three-dimensional reference cascade characteristic parallel characteristic

Wave–particle duality in a Raman atom interferometer

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Chinese Physics B 2015年第8期24卷 166-169页

作者：贾爱爱杨俊颜树华胡青青罗玉昆朱诗尧 College of Mechatronic Engineering and automation National University of Defense Technology Beijing Computational Science research Center

We theoretically investigate the wave–particle duality based on a Raman atom interferometer, via the interaction between the atom and Raman laser, which is similar to the optical Mach–Zehnder interferometer. The wave and which-way information are stored in the atomic internal states. For the φ- π- π /2 type of atom interferometer, we find that the visibility(V) and predictability(P) still satisfy the duality relation, P2+ V2≤ 1.

关键词： complementarity wave–particle duality atom interferometer Raman pulse

Modeling and adaptive motion/force tracking for vertical wheel on rotating table

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Journal of Systems Engineering and Electronics 2015年第5期26卷 1060-1069页

作者： Zhongcai Zhang Yuqiang Wu Wei Sun School of automation Southeast University inst.tute of automation Qufu Normal University

This paper is devoted to the problem of modeling and adaptive motion/force tracking for a class of nonholonomic dynamic systems with affine constraints(NDSAC): a vertical wheel on a rotating table. Prior to the development of tracking controller,the dynamic model of the wheel in question is derived in a meticulous manner. A continuously differentiable friction model is also considered in the modeling. By exploiting the inherent cascade interconnected structure of the wheel dynamics, an adaptive motion/force tracking controller is presented guaranteeing that the trajectory tracking errors asymptotically converge to zero while the contact force tracking errors can be made small enough by tuning design parameters. Simulation results are provided to validate the effectiveness of the proposed tracking methodology.

关键词： nonholonomic system adaptive motion/force tracking mechanics model affine constraint