检索结果-南通市图书馆

Complete synchronization of uncertain chaotic dynamical network via a simple adaptive control

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2008年第1期17卷 80-86页

作者：肖玉柱徐伟李秀春唐素芳 Department of Applied Mathematics Northwestern Polytechnical University

In this paper, based on the invaxiance principle of differential equations, we propose a simple adaptive control method to synchronize the network with coupling of the general form. Comparing with other control approaches, this scheme only depends on each node＇s state output. So we need not to know the concrete network structure and the solutions of the isolate nodes of the network in advance. In order to demonstrate the effectiveness of the method, a special example is provided and numerical simulations are performed. The numerical results show that our control scheme is very effective and robust against the weak noise.

关键词： complete synchronization adaptive control dynamical network

Robust adaptive control of hypersonic flight vehicle with asymmetric AOA constraint

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2020年第11期63卷 195-207页

作者： Yuyan GUO Bin XU Weixin HAN Shuai LI Yueping WANG Yu ZHANG School of Automation Northwestern Polytechnical University Department of Computing The Hong Kong Polytechnic University Flight Automatic control Research Institute State Key Laboratory of Industrial control Technology College of Control Science and EngineeringZhejiang University

This paper investigates the state-constrained controller design of a hypersonic flight vehicle(HFV) based on an asymmetric barrier Lyapunov function(ABLF). The robust adaptive back-stepping controller with integral terms is applied for the HFV longitudinal dynamics. Considering the asymmetric angle of attack(AOA) constraint caused by the unique structure and scramjet, the controller is modified by constructing an ABLF, where the asymmetric constraint on AOA tracking error is introduced. Combined with the constraint on virtual control, the AOA is restricted to a predefined asymmetric interval. The system stability and the AOA constraint are guaranteed via Lyapunov analysis. Simulation results verify that the AOA can be kept in the given asymmetric interval while the altitude reference signal is tracked.

关键词： hypersonic flight vehicle HFV integral back-stepping control adaptive control asymmetric barrier Lyapunov function ABLF angle of attack (AOA) constraint

Start-up current adaptive control for sensorless high-speed brushless DC motors based on inverse system method and internal mode controller

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2017年第1期30卷 358-367页

作者： He Yanzhao Zheng Shiqiang Fang Jiancheng School of Instrumentation Science and Opto-electronics Engineering Beihang University Beijing 100083 China Beijing Engineering Research Center of High-Speed Magnetically Suspended Motor Technology and Application Beijing 100083 China

The start-up current control of the high-speed brushless DC（HS-BLDC） motor is a challenging research topic. To effectively control the start-up current of the sensorless HS-BLDC motor, an adaptive control method is proposed based on the adaptive neural network（ANN）inverse system and the two degrees of freedom（2-DOF） internal model controller（IMC）. The HS-BLDC motor is identified by the online least squares support vector machine（OLS-SVM） algorithm to regulate the ANN inverse controller parameters in real time. A pseudo linear system is developed by introducing the constructed real-time inverse system into the original HS-BLDC motor system. Based on the characteristics of the pseudo linear system, an extra closed-loop feedback control strategy based on the 2-DOF IMC is proposed to improve the transient response performance and enhance the stability of the control system. The simulation and experimental results show that the proposed control method is effective and perfect start-up current tracking performance is achieved.

关键词： adaptive control Brushless DC motors Inverse systems Internal model controller Neural networks Start-up Support vector machines

Finite-time command filtered adaptive control for nonlinear systems via immersion and invariance

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2021年第9期64卷 151-164页

作者： Jinpeng YU Peng SHI Xinkai CHEN Guozeng CUI School of Automation Qingdao University School of Electrical and Electronic Engineering The University of Adelaide Department of Electronic and Information Systems Shibaura Institute of Technology School of Electronic and Information Engineering Suzhou University of Science and Technology

This paper investigates the problem of finite-time adaptive output tracking control for strictfeedback nonlinear systems with parametric uncertainties. Command signals and their derivatives are generated by a new command filter based on a second-order finite-time differentiator, which attenuates the chattering phenomenon. The parameter estimations are achieved by an immersion and invariance approach without requiring the certainty equivalence principle. The finite-time adaptive controller is constructed via a backstepping design method, a finite-time command filter, and a modified fractional-order error compensation mechanism. The proposed control strategy guarantees the finite-time boundedness of all signals in the closed-loop system, and the tracking error is driven into an arbitrarily small neighborhood of the origin in finite time. Finally, the new design technique is validated in a simulation example of the electromechanical system.

关键词： adaptive control finite-time control command-filtered backstepping immersion and invariance

Model Based adaptive control and Disturbance Compensation for Underwater Vehicles

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2018年第1期31卷 114-126页

作者： Hai Huang Guo-Cheng Zhang Ji-Yong Li Qiang Zhang Jin-Yu Xu Hong-De Qin National Key Laboratory of Science and Technology on Autonomous Underwater Vehicle Harbin Engineering University

Underwater vehicles are being emphasized as highly integrated and intelligent devices for a significant number of oceanic operations. However, their precise operation is usually hindered by disturbances from a tether or manipulator because their propellers are unable to realize a stable suspension. A dynamic multi-body model-based adaptive controller was designed to allow the controller of the vehicle to observe and compensate for disturbances from a tether or manipulator. Disturbances, including those from a tether or manipulator, are deduced for the observation of the controller. An analysis of a tether disturbance covers the conditions of the surface, the underwater area, and the vehicle end point. Interactions between the vehicle and manipulator are mainly composed of coupling forces and restoring *** verify the robustness of the controller, path-following experiments on a streamlined autonomous underwater vehicle experiencing various disturbances were conducted in Song Hua Lake in China. Furthermore,path-following experiments for a tethered open frame remote operated vehicle were verified for accurate cruising with a controller and an observer, and vehicle and manipulator coordinate motion control during the simulation and experiments verified the effectiveness of the controller and observer for underwater operation. This study provides instructions for the control of an underwater vehicle experiencing disturbances from a tether or manipulator.

关键词： Underwater vehicle adaptive control Disturbance observer Multi-body dynamic model

Characteristic model based all-coefficient adaptive control of an AMB suspended energy storage flywheel test rig

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2018年第11期61卷 113-127页

作者： Xujun LYU Long DI Zongli LIN Yefa HU Huachun WU School of Mechanical and Electronic Engineering Wuhan University of Technology Hubei Provincial Engineering Technology Research Center for Magnetic Suspension ASML-HMI 1762 Automation Pkwy 4. Charles L.Brown Department of Electrical and Computer Engineering University of Virginia

Feedback control of active magnetic bearing(AMB) suspended energy storage flywheel systems is critical in the operation of the systems and has been well studied. Both the classical proportional-integralderivative(PID) control design method and modern control theory, such as H∞ control and μ-synthesis,have been explored. PID control is easy to implement but is not effective in handling complex rotordynamics. Modern control design methods usually require a plant model and an accurate characterization of the uncertainties. In each case, few experimental validation results on the closed-loop performance are available because of the costs and the technical challenges associated with the construction of experimental test *** this paper, we apply the characteristic model based all-coefficient adaptive control(ACAC) design method for the stabilization of an AMB suspended flywheel test rig we recently constructed. Both simulation and experimental results demonstrate strong closed-loop performance in spite of the simplicity of the control design and implementation.

关键词： adaptive control characteristic modeling energy storage flywheels active magnetic bearings

Direct adaptive control for a class of MIMO nonlinear discrete-time systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2014年第1期25卷 129-137页

作者： Lei Li Zhizhong Mao Automation Institute College of Information Science and EngineeringNortheastern University College of Electricity Information and Automation Qufu Normal University

This paper considers the problem of adaptive con-trol for a class of multiple input multiple output （MIMO） nonlinear discrete-time systems based on input-output model with unknown interconnections between subsystems. Based on the Taylor ex-pand technology, an equivalent model in affine-like form is derived for the original nonaffine nonlinear system. Then a direct adap-tive neural network （NN） control er is implemented based on the affine-like model. By finding an orthogonal matrix to tune the NN weights, the closed-loop system is proven to be semiglobal y uni-formly ultimately bounded. The σ-modification technique is used to remove the requirement of persistence excitation during the adaptation. The control performance of the closed-loop system is guaranteed by suitably choosing the design parameters.

关键词： adaptive control nonaffine nonlinear discrete-timesystem equivalent affine-like model neural network (NN).

Passive adaptive control of chaos in synchronous reluctance motor

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2008年第1期17卷 92-97页

作者：韦笃取罗晓曙 College of Physics and Electronic Engineering Guangxi Normal University

The performance of synchronous reluctance motor （SynRM） degrades due to chaos when its systemic parameters fall into a certain area. To control the undesirable chaos in SynRM, a passive control law is presented in this paper, which transforms the chaotic SynRM into an equivalent passive system. It is proved that the equivalent system can be asymptotically stabilized at the set equilibrium point, namely, chaos in SynRM can be controlled. Moreover, in order to eliminate the influence of undeterministic parameters, an adaptive law is introduced into the designed controller. Computer simulation results show that the proposed controller is very effective and robust against the uncertainties in systemic parameters. The present study may help to maintain the secure operation of industrial servo drive system.

关键词： chaos control passive control adaptive control synchronous reluctance motor

AN adaptive control STRATEGY FOR PROPER MESH DISTRI-BUTION IN LARGE EDDY SIMULATION

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2010年第6期22卷 865-870页

作者： ZHANG Bin WANG Tong GU Chuan-gang DAI Zheng-yuan Key Laboratory for Power Machinery and Engineering of Ministry of Education Shanghai Jiao Tong University Shanghai 200240 China Trane＇s Asia-Pacific Research Center Shanghai 200001 China

The Filtering Grid Scale （FGS） of sub-grid scale models does not match with the theoretical Proper FGS （PFGS） because of the improper mesh. Therefore, proper Large Eddy Simulation （LES） Mesh is very decisive for better results and more economical cost. In this work, the purpose is to provide an adaptive control strategy for proper LES mesh with turbulence theory and CFD methods. A new expression of PFGS is proposed on the basis of -5/3 law of inertial sub-range and the proper mesh of LES can be built directly from the adjustment of RANS mesh. A benchmark of the backward facing step flow at Re = 5147 is provided for application and verification. There are three kinds of mesh sizes, including the RANS mesh, LAM （LES of adaptive-control mesh）, LFM （LES of fine mesh）, employed here. The grid number of LAM is smaller than those of LFM evidently, and the results of LAM are in a good agreement with those of DNS and experiments. It is revealed that the results of LAM are very close to those of LFM. The conclusions provide positive evidences for the novel strategy.

关键词： Large Eddy Simulation (LES) Proper Filtering Grid Scale (PFGS) turbulence -5/3 law adaptive control