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Science China(Information Sciences) 2017年第12期60卷 20-32页

作者： Guoqing ZHANG Yingjie DENG Weidong ZHANG Zhijian SUN Department of Automation Shanghai Jiao Tong University Navigation College Dalian Maritime University

This article investigates the output-feedback control of a class of stochastic nonlinear system with time-varying delay and unknown dead zone. A robust neural stabilizing algorithm is proposed by using the circle criterion, the NNs approximation and the MLP(minimum learning parameter) technique. In the scheme, the nonlinear observer is first designed to estimate the unmeasurable states and the assumption "linear growth" of the nonlinear function is released. Furthermore, the uncertainty of the whole system(including the perturbation of time-varying delay) is lumped and compensated by employing one RBF NNs(radial basis function neural networks). Though, only two weight-norm related parameters are required to be updated online for the merit of the MLP technique. And the gain-inversion related adaptive law is targetly designed to mitigate the adverse effect of unknown dead zone. Comparing with the previous work, the proposed algorithm obtains the advantage:a concise form and easy to implementation due to its less computational burden. The theoretical analysis and comparison example demonstrate the substantial effectiveness of the proposed scheme.

关键词： stochastic system robust neural control time delay dead zone output-feedback

Adaptive dynamic surface control of nonlinear systems with dead zone

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Adaptive dynamic surface control of nonlinear systems with d...

第32届中国控制与决策会议

作者： Dexin Fan Yixin Yin School of Automation and Electrical Engineering University of Science and Technology Beijing Key Laboratory of Knowledge Automation for Industrial Processes Ministry of Education

In this paper,we present control designs for a class of single-input and single-output（SISO） strict-feedback nonlinear systems with unknown dead-zone *** consider the dead zone dynamics,the nonlinear dead zone is first represented as a linear time-varying system with a bounded ***,a backstepping control method is proposed for adaptive controller *** addition to using dynamic surface control（DSC） to solve the problem of the "explosion of complexity",a compensating signal is added to eliminate the effect of the dynamic surface filter ***,the prediction error between the system state and the serial-parallel estimation model is taken into ***,neural networks（NN） are used to deal with the unknown functions in the ***,simulations illustrate the effectiveness of the proposed approach.

关键词： Adaptive Control Neural Networks dead zone Dynamic surface control

Adaptive Control Design for Unknown System with Nonlinear Perturbed dead-zone

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Adaptive Control Design for Unknown System with Nonlinear Pe...

第二十九届中国控制会议

作者： HERRMANN Guido Department of Mechanical Engineering University of Bristol

Adaptive control design is studied for a class of unknown systems with a nonlinear perturbed dead-zone *** nonlinear dead-zone can be represented as a time-varying system with a disturbance-like *** adaptive controller is first constructed using functions acting as the upper bounds of the nonlinear dynamics,which are independent on the dead-zone ***-varying delays are also dealt with while the construction of an inverse dead-zone model is not ***,a neural controller is further proposed using a neural network with only a scalar weight parameter,such that the requirement on the bounds functions can be *** effectiveness of the developed approaches is illustrated by simulations.

关键词： dead zone Adaptive Control Nonlinear System Time-delay

TOFD detection of shallow subsurface defects in aluminum alloy thin plates by half-skip mode-converted wave

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Chinese Journal of Aeronautics 2024年第6期37卷 454-463页

作者： Shijie JIN Zhicheng WANG Zhongbing LUO NDT&E Laboratory Dalian University of TechnologyDalian 116085China

Aluminum alloy is widely applied to the aerospace ***,the inspection of thin plates using Time-of-Flight Diffraction(TOFD)technique is restricted by the near-surface dead zone because of the coupling between diffracted longitudinal wave and lateral *** halfskip mode-converted wave is introduced to decrease dead zone and detect defects in aluminum alloy thin plates by increasing ray path and propagation *** quantitative correlation for the diffracted shear wave from longitudinal back-wall wave is deduced in combination with the acoustic path,realizing the accurate location of shallow subsurface *** and experimental results indicate that the dead zone is decreased by 38% by the half-skip mode-converted wave,and the location errors are within 5% for the aluminum alloy plate with a thickness of 7.0 *** to other alternative TOFD techniques,half-skip mode-converted wave has better response amplitude and positioning accuracy,demonstrating strong applicability in TOFD inspection of thin plates.

关键词： Ultrasonic testing Time-of-Flight Diffraction(TOFD) dead zone Half-skip mode-converted wave Quantitative detection

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FINITE-TIME TRACKING CONTROL FOR MOTOR SERVO SYSTEMS WITH UNKNOWN dead-zoneS

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Journal of Systems Science & Complexity 2013年第6期26卷 940-956页

作者： CHEN Qiang YU Li NAN Yurong College of Information Engineering Zhejiang University of Technology

A finite-time tracking control scheme is proposed in this paper based on the terminal sliding mode principle for motor servo systems with unknown nonlinear dead-zone *** using the differential mean value theorem,the dead-zone is represented as a time-varying system and thus the inverse compensation approach is ***,an indirect terminal sliding mode control(ITSMC)is developed to guarantee the finite-time convergence of the tracking error and to overcome the singularity problem in the traditional terminal sliding mode *** the proposed controller design,the unknown nonlinearity of the system is approximated by a simple sigmoid neural network,and the approximation error is diminished by employing a robust *** experiments on a turntable servo system are conducted to show the superior performance of the proposed method.

关键词： dead zone finite-time control neural network servo system.

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ADAPTIVE HARMONIC CANCELLATION APPLIED IN ELECTRO-HYDRAULIC SERVO SYSTEM WITH ANN

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Chinese Journal of Mechanical Engineering 2004年第4期17卷 628-630页

作者： YaoJianjun WuZhenshun HanJunwei YueDonghai SchoolofMechanicalandElectncalEngineering HarbinInstituteofTechnologyHarbin150001.China

The method for harmonic cancellation based on artificial neural network (ANN)is proposed. The task is accomplished by generating reference signal with frequency that should beeliminated from the output. The reference input is weighted by the ANN in such a way that it closelymatches the harmonic. The weighted reference signal is added to the fundamental signal such thatthe output harmonic is cancelled leaving the desired signal alone. The weights of ANN are adjustedby output harmonic, which is isolated by a bandpass filter. The above concept is used as a basis forthe development of adaptive harmonic cancellation (AHC) algorithm. Simulation results performedwith a hydraulic system demonstrate the efficiency and validity of the proposed AHC control scheme.

关键词： dead zone Higher harmonic Harmonic distortion Artificial neural network (ANN) Adaptive harmonic cancellation (AHC)

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CFD analysis for mixing performance of different types of household biodigesters

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Clean Energy 2022年第2期6卷 325-334页

作者： Sagar Shrestha Sunil Prasad Lohani Renewable and Sustainable Energy Laboratory Department of Mechanical EngineeringKathmandu UniversityNepal

Household biodigesters are self-mixing anaerobic digesters used mostly in rural areas of developing countries as a reliable source of clean cooking *** an efficient anaerobic digestion process,the mixing of slurry inside the digester is regarded as one of the most important *** this study,the mixing of slurry in three different designs of household digesters,namely the fixed-dome digester(GGC 2047 model),plug-flow digester and prefabricated plastic digester,are investigated and compared using compu-tational fluid dynamics.A 3D transient simulation is performed using a multiphase volume of fluid(VOF)model in Ansys^(■)Fluent release *** rheological properties of the feedstock are considered identical for all three *** volume of the plug-flow and prefabricated plastic digesters is designed to be 1 m^(3) while the volume of the GGC 2047 digester was 6 m^(3) as the standard size of the household *** regions inside the digester where the velocity of slurry isdead zones and the obtained results were analysed and compared using velocity patterns and dead-zone *** is found that the prefabricated plastic digester model has a relatively higher percentage of dead volume(74.6%)and the plug-flow digester has the lowest per-centage(54%)of dead volume among digesters that were compared in this *** study will serve as the basis for designers and researchers to improve the design of household digesters for better mixing performances.

关键词： household biodigesters dead zone CFD anaerobic digestion mixing biomass Ansys Fluent

A Fault-Tolerant Control Technique for Accommodation of Partial Actuator Faults

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A Fault-Tolerant Control Technique for Accommodation of Part...

2010 Chinese Control and Decision Conference

作者： Behnam Allahverdi Charandabi Ali Khaki Sedigh Farzad R.Salmasi School of Electrical Engineering Faculty of EngineeringTehran UniversityTehranIran Faculty of Electrical Engineering Khajeh Nasir Toosi University of TechnologyTehranIran

＜正＞In this paper,a robust adaptive controller for accommodation of partial actuator faults is *** proposed controller is based on the robust adaptive model-reference control scheme with improved dead zone *** common problem of steady state error in robust adaptive systems with simple dead zone modification is resolved by tuning a specific parameter inside the dead zone with a different adaptive *** types of actuator faults including output offset,loss of efficiency,and output delay are compensated with the proposed *** behave these faults as uncertainties and disturbances. The proposed technique does not need an extra unit for fault detection and *** simulation studies are performed to illustrate the effectiveness of the proposed control technique versus the robust adaptive controller with simple dead zone modification.

关键词： Fault-tolerant control Robust adaptive control dead zone Uncertainty

A Modified PFD Based PLL with Frequency Dividers in 0.18-µm CMOS Technology

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Circuits and Systems 2016年第13期7卷 4169-4185页

作者： N. K. Anushkannan H. Mangalam Department of Electronics and Communication Engineering Tamil Nadu College of Engineering Coimbatore India Department of Electronics and Communication Engineering Sri Ramakrishna Institute of Technology Coimbatore India

This paper introduces a modified design of CMOS dynamic Phase Frequency Detector (PFD). The proposed PFD circuit (PPFD) is designed, simulated and the results obtained are analyzed. In order to reduce dead zone, internal signal routing is used in the PPFD circuit. To extend, Phase Locked Loop (PLL) is designed and it is verified with two different Frequency Divider (FD) circuits. There is a decrease in area of the PPFD circuit with 16 transistors and dissipates power of 40.8 pW for 1.2 V power supply. The pre-layout simulation result shows that the PPFD circuit has an elimination of a dead zone. Further, it works with the high speed and reduced power operated in the reference frequency of 50 MHz and the feedback frequency up to 4 GHz.

关键词： PFD dead zone VCO Power PLL

Stability Analysis of Switching System in Space Power Supply

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Stability Analysis of Switching System in Space Power Supply

第32届中国控制与决策会议

作者： Ningxin Wu Qing Wu Jiahao Shi Xinran Wu Yongqing Su College of Electronics and Information Engineering Tongji University Air Force Research Institute Shanghai Institute of Space Power Supply

In order to maintain the stability of the bus voltage,the space power supply switches between the discharge circuit module,the charging circuit module and the shunt circuit module according to the change of the solar cell and the load,and the switching transition process can be approximately equivalent to the dead zone *** this paper,the system is modeled by the small-signal modeling method,and according to the average dwell time method,we can find the average dwell time index which can make the system *** we calculate the real-time dwell time index of the system by Markov analysis method,and compare with the average dwell time index to judge the stability of the ***,the effectiveness of the proposed method is proved by simulation.

关键词： Switching System dead zone Lyapunov Function and Average Dwell Time