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Donor-acceptor(D-A)terpolymers based on alkyl-DPP and t-BocDPP moieties for polymer solar cells

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Chinese Chemical Letters 2017年第12期28卷 2223-2226页

作者： fateh ullah Sun Qian Weitao Yang Muhammad Naeem Shah Zhongqiang Zhang Hongzheng Chen Chang-Zhi Li MOE Key Laboratory of Macromolecular Synthesis and Functionalization State Key Laboratory of Silicon MaterialsDepartment of Polymer Science andEngineeringZhejiang UniversityHangzhou 310027China

A series of low band gap terpolymers based on 4,8-bis（5-（2-ethylhexyl）thiophen-2-yl）benzo[l,2-b：4,5- b＇]dithiophene （BDTr） and diketopyrrolopyrrole （DPP） with varied solubilizing groups （i.e., tert- butoxycarbonyl, t-Boc and 2-octyldodecyl） are developed as electron donors for bulk heterojunction （BHJ） polymer solar cells （PSCs）. The results reveal that the one with 50% t-Boc concentration （P3） performs better than the other terpolymers used in this study in conventional PSC devices with a power conversion efficiency of 2.92%.

关键词： Conjugated polymerOrganic semiconductorPolymer solar cellsBulk heterojunctionDiketopyrrolopyrrole

A Precise Robust Fuzzy Control of Robots Using Voltage Control Strategy

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International Journal of Automation and computing 2013年第1期10卷 64-72页

作者： Mohammad Mehdi fateh Sara fateh Department of Electrical and Robotic Engineering Shahrood University of Technology

Fuzzy control of robot manipulators with a decentralized structure is facing a serious challenge. The state-space model of a robotic system including the robot manipulator and motors is in non-companion form, multivariable, highly nonlinear, and heavily coupled with a variable input gain matrix. Considering the problem, causes and solutions, we use voltage control strategy and convergence analysis to design a novel precise robust fuzzy control （PRFC） approach for electrically driven robot manipulators. The proposed fuzzy controller is Mamdani type and has a decentralized structure with guaranteed stability. In order to obtain a precise response, we regulate a fuzzy rule which governs the origin of the tracking space. The proposed design is verified by stability analysis. Simulations illustrate the superiority of the PRFC over a proprotional derivative like （PD-like） fuzzy controller applied on a selective compliant assembly robot arm （SCARA） driven by permanent magnet DC motors.

关键词： Precise performance fuzzy control robot manipulator voltage control strategy convergence analysis stability analysis

Robust Control of Robotic Manipulators in the Task-Space Using an Adaptive Observer Based on Chebyshev Polynomials

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Journal of Systems Science & Complexity 2020年第5期33卷 1360-1382页

作者： GHOLIPOUR Reza fateh Mohammad Mehdi Department of Electrical and Robotic Engineering Shahrood University of Technology*** ShahroodIran

In this paper,an adaptive observer for robust control of robotic manipulators is *** lumped uncertainty is estimated using Chebyshev ***,the uncertainty upper bound is required in designing observer-controller ***,obtaining this bound is a challenging *** solve this problem,many uncertainty estimation techniques have been proposed in the literature based on neuro-fuzzy *** an alternative,in this paper,Chebyshev polynomials have been applied to uncertainty estimation due to their simpler structure and less computational *** on strictly-positive-rea Lyapunov theory,the stability of the closed-loop system can be *** Chebyshev coefficients are tuned based on the adaptation rules obtained in the stability ***,to compensate the truncation error of the Chebyshev polynomials,a continuous robust control term is designed while in previous related works,usually a discontinuous term is *** SCARA manipulator actuated by permanent magnet DC motors is used for computer *** results reveal the superiority of the designed method.

关键词： Adaptive observer Chebyshev polynomials electrically driven robot manipulators robust control uncertainty estimation

Elastic-viscoplastic constitutive model for capturing the mechanical response of polymer composite at various strain rates

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Journal of Materials Science & Technology 2020年第22期54卷 12-17页

作者： Shahzad fateh Ali Jitang Fan State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing700087China

Recently, polymer composites, consisting of hard segments and soft segments blend, attract a broad research interest because of the high flow stress and large deformation under a high rate loading. They display an outstanding energy absorption capability for impact resistant engineering. In this paper,a physics-based elastic-viscoplastic constitutive model is developed which accounts the activation of molecular chains motion at different segments upon an applied stress as well as the rate dependency of mechanical properties. Accordingly, finite element simulations are conducted to derive the mechanical performance at various strain rates. It involves the linearly elastic deformation to yielding, softening behavior with a slight decrease of stress, plastic flow at a plateau stress accompanied by a considerable straining, densification with a fast increase of stress. The results achieved from model simulations match well with these obtained by experiments and the mechanical response in the strain rate range from 0.0001 s^(-1) to 8000 s^(-1) can be captured by this model. Finally, energy absorption capability of the polymer composite is discussed, and the physical mechanisms in material science are addressed by post-loading analysis. This work is full of interest to develop the constitutive model for designing the impact-resistant polymers and illustrating the dynamic mechanical response, which will promote the application of light-weight transparent protection structure against a high-speed impact.

关键词： Polymer composite Constitutive model Strain rate Mechanical behavior

Modeling and Robust Discrete LQ Repetitive Control of Electrically Driven Robots

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International Journal of Automation and computing 2013年第5期10卷 472-480页

作者： Mohammad Mehdi fateh Maryam Baluchzadeh Department of Electrical and Robotic Engineering Shahrood University of Technology

Discrete linear quadratic control has been efciently applied to linear systems as an optimal ***,a robotic system is highly nonlinear,heavily coupled and *** overcome the problem,the robotic system can be modeled as a linear discrete-time time-varying system in performing repetitive *** modeling motivates us to develop an optimal repetitive *** contribution of this paper is *** the frst time,it presents discrete linear quadratic repetitive control for electrically driven robots using the mentioned *** proposed control approach is based on the voltage control ***,uncertainty is efectively compensated by employing a robust time-delay *** uncertainty can include parametric uncertainty,unmodeled dynamics and external *** highlight its ability in overcoming the uncertainty,the dynamic equation of an articulated robot is introduced and used for the simulation,modeling and control *** analysis verifes the proposed control approach and simulation results show its efectiveness.

关键词： Discrete linear quadratic control repetitive control electrically driven robot robust time-delay controller uncertainty

Frequency-Domain Estimation of Continuous-Time Bilinear Processes

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Communications in Mathematics and Statistics 2021年第4期9卷 379-403页

作者： Abdelouahab Bibi fateh Merahi Department of Mathematics Larbi Ben M’hidi UniversityOum El BouaghiAlgeria Department of Mathematics Abbes Laghrour UniversityBP 1252 Route de Batna40004 KhenchelaAlgeria

In this paper,we study in frequency domain someprobabilistic and statistical properties of continuous-time version of the well-known bilinear processes driven by a standard Brownian *** class of processes which encompasses many commonly used processes in the literature was defined as a nonlinear stochastic differential equation which has raised considerable interest in the last few ***,the L_(2)-structure of the process is studied and its covariance function is *** structures will lead to study the strong consistency and asymptotic normality of the Whittle estimates of the unknown parameters involved in the *** sample properties are also considered through Monte Carlo *** end,the model is then used to model the exchanges rate of the Algerian Dinar against the US dollar.

关键词： Continuous-time bilinear processes Whittle estimator Consistency Asymptotic normality

Effect of Nb on Austenite Formation and Decomposition in an X80 Linepipe Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 658-663页

作者： fateh Fazeli Matthias Militzer The Centre for Metallurgical Process Engineering The University of British Columbia VancouverBCCanada V6T 1Z 4

Advanced high strength steels for pipeline applications,e.g.X80 grades,have complex microstructures and are frequently microalloyed with *** the hot rolled product it is sought to have Nb precipitated as Nb(CN).However,when processing these steels Nb may be in solution and critically affects the microstructure evolution,*** decomposition on the run-out table of a hot ***,microstructure changes in the heat affected zone (HAZ) during girth welding of these linepipe steels may occur with Nb precipitated or in *** the HAZ,depending on welding procedures,the material undergoes a number of austenite formation and decomposition cycles and the amount of Nb in solution varies along these *** selected positions of the HAZ,thermal cycles peak at the intercritical region and the partial formation of austenite and subsequent decomposition constitutes additional *** reliable process models for run-out table cooling and the HAZ hinges on an accurate tracking of microstructure evolution,which is strongly influenced by the amount of Nb in *** present study provides more insight into the effect of Nb on austenite formation and ***,a novel experimental methodology is presented to measure quantitatively the effect of Nb on transformation temperatures pertinent to austenite decomposition,notably ferrite.A model for ferrite formation that accounts for solute drag of Nb is proposed to describe the experimental ***,an experimental study will be presented to quantify the effect of Nb in and out of solution on austenite formation in the intercritical *** is found that the morphology of intercritical austenite,as well as the kinetics of its formation is strongly affected by the starting microstructure and the state of Nb.

关键词： Effect of Nb on Austenite Formation and Decomposition in an X80 Linepipe Steel HAZ

Discrete-time indirect adaptive fuzzy control for robot manipulators

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International Journal of Intelligent Computing and Cybernetics 2014年第4期7卷 382-396页

作者： Mohammad Mehdi fateh Siamak Azargoshasb Department of Electrical Engineering University of ShahroodShahroodIran

Purpose–The purpose of this paper is to design a discrete indirect adaptive fuzzy controller for a robotic *** paper addresses how to overcome the approximation error of the fuzzy system and uncertainties for asymptotic tracking control of robotic *** uncertainties include parametric uncertainty,un-modeled dynamics,discretization error and external ***/methodology/approach–The proposed controller is model-free and voltage-based in the form of discrete-time Mamdani fuzzy *** parameters of fuzzy controller are adaptively tuned for asymptotic tracking of a desired trajectory.A robust control term is used to compensate the approximation error of the fuzzy *** adaptive mechanism is derived based on the stability ***–The proposed model-free discrete control is robust against all uncertainties associated with the robot manipulator and *** approximation error of the fuzzy system is well compensated to achieve asymptotic tracking of the desired *** analysis and simulation results show its efficiency in the tracking ***/value–A novel discrete indirect adaptive fuzzy controller is designed for electrically driven robot manipulators using the voltage control *** novelty of this paper is compensating the approximation error of the fuzzy system and discretizing error for asymptotic tracking of the desired trajectory.

关键词： Nonlinear control Fuzzy logic Intelligent control Robotics Adaptive control

Guaranteed-stability adaptive fuzzy control of a hydraulic elevator

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International Journal of Intelligent Computing and Cybernetics 2013年第3期6卷 252-271页

作者： Mohammad Mehdi fateh Mohaddeseh Amerian Department of Electrical and Robotic Engineering Shahrood University of TechnologyShahroodIran

Purpose-A hydraulic elevator including the hydraulic actuator and cabin is highly nonlinear with many parameters and *** state-space model is in non-companion form and uncertain due to the parametric errors,flexibility of the ropes,friction and external load disturbances.A model-based control cannot perform well while a precise model is not available and all state variables cannot be *** overcome the problems,this paper aims to develop a direct adaptive fuzzy control(DAFC)for the hydraulic ***/methodology/approach-The controller is an adaptive PD-like Mamdani type fuzzy controller using position error and velocity error as *** design is based on the stability ***-The proposed control can overcome uncertainties,guarantee stability,provide a good tracking performance and operate as active vibration suppression by tracking a smooth *** controller is not involved in the nonlinearity,uncertainty and vibration of the system due to being free from *** performance is superior to a PD-like fuzzy controller due to being adaptive as illustrated by ***/value-The proposed DAFC is applied for the first time on the hydraulic *** to classic adaptive fuzzy,it does not require all system *** addition,it is not limited to the systems,which have the state-space model in companion form and constant input gain,thus is much less computational and easier to implement.

关键词： Nonlinear control Adaptive control Fuzzy logic Intelligent control