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Vision-based adaptive control of a 3-RRR parallel positioning system

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Science China(Technological Sciences) 2018年第8期61卷 1253-1264页

作者： YAO Sheng LI Hai ZENG Lei zhang xianmin Guangdong Key Laboratory of Precision Equipment and Manufacturing Technology School of Mechanical and Automotive EngineeringSouth China University of Technology

The macro positioning stage with high-precision and rapid positioning ability plays a crucial role in the macro-micro combination positioning system. In this paper, we develop a practical method for the control of a 3-RRR planar positioning system using online vision measurement as feedback. In this method, a monocular vision system is established to accomplish highprecision online pose measurement for the 3-RRR manipulator. Additionally, a robust and operable adaptive control algorithm,which incorporates a fuzzy controller and a PI controller, is employed to achieve precise and rapid positioning of the 3-RRR positioning system. A series of experiments are conducted to verify the positioning performances of the proposed method, and a conventional PI control algorithm is utilized for comparison. The experimental results indicate that using the proposed control approach, the parallel positioning system obtains high precision and shows higher efficiency and robustness, especially for the time-varying positioning system.

关键词： adaptive positioning control 3-RRR planar parallel manipulator machine vision-aided system full-closed loop control

Design of single-axis flexure hinges using continuum topology optimization method

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Science China(Technological Sciences) 2014年第3期57卷 560-567页

作者： ZHU BenLiang zhang xianmin FATIKOW Sergej Key laboratory of Precision Equipment and Manufacturing Technology of Guangdong Province South China University of Technology Division Microrobotics Department of Computing Science Uhlhornsweg 84A1 26111 Oldenburg Germany

The design of compliant hinges has been extensively studied in the size and shape level in the *** paper presents a method for designing the single-axis flexure hinges in the topology *** kinds of hinges,that is,the translational hinge and the revolute hinge,are *** basic optimization models are developed for topology optimization of the translational hinge and the revolute hinge,*** objective for topology optimization of flexure hinges is to maximize the compliance in the desired direction meanwhile minimizing the compliances in the other *** constraints for accomplishing the translational and revolute requirements are *** popular Solid Isotropic Material with Penalization method is used to find the optimal flexure hinge topology within a given design *** results are performed to illustrate the validity of the proposed method.

关键词： topology optimization translational hinge SIMP compliant mechanisms revolute hinge

Spring-Joint Method for Topology Optimization of Planar Passive Compliant Mechanisms

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Chinese Journal of Mechanical Engineering 2013年第6期26卷 1063-1072页

作者： JIN Mohui zhang xianmin ZHU Benliang WANG Nianfeng Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology South China University of Technology

There is seldom approach developed for the initial topology design of flexure-based compliant mechanisms. The most commonly-used approaches, which start with an existing rigid-body mechanism, do not consider the performances between different topologies. Moreover, they rely heavily on the rigid-body topology, therefore limit the diversity of compliant mechanisms topology. To obtain the optimal initial topology of such mechanisms directly from problem specifications without referencing to the existing mechanism topologies, a spring-joint method is presented for a restricted class of the serial passive flexure-based compliant mechanisms, which are the building blocks of parallel compliant mechanisms. The topology of the compliant mechanisms is represented by a serial spring-joint mechanism（SSJM） that is a traditional rigid-body mechanism with a torsional spring acting on each joint, and is described by position vectors of the spring-joints. A simplified compliance matrix, determined by the position vectors, is used to characterize the tip of the SSJM kinematically, and is optimized to ensure the desired freedoms of the compliant mechanisms during optimization. The topology optimization problem is formulated as finding out the optimal position of the spring-joints in a blank design domain with an objective function derived from the simplified compliance matrix. In design examples, syntheses of the compliant mechanisms with both single freedom and two decoupled freedoms are presented to illustrate the proposed method. The proposed method provides a new way for the initial design of flexure-based compliant mechanisms.

关键词： compliant mechanism synthesis topology optimization spring-joint

TOPOLOGY OPTIMIZATION OF MULTIPLE INPUTS AND MULTIPLE OUTPUTS COMPLIANT MECHANISMS

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Chinese Journal of Mechanical Engineering 2007年第1期20卷 82-85页

作者： zhang xianmin OUYANG Gaofei WANG Hua School of Mechanical Engineenng. South China University of Technology Guangzhou 510640 China

An optimal topology design method for multiple inputs and multiple outputs compliant micro-manipulation system is presented. Firstly, the topology design problem is posed in terms of a multiple inputs load and several specified output deflections. The compliance and stiffness of the system are expressed by the mutual potential energy and strain energy, respectively, which can be controlled by a multi-critaria objective function. Secondly, based on the optimality criteria method, a model solution algorithm is presented. Finally, a numerical example is presented to show the validity oftbe presented technique. The optimal topology ofa 4 inputs and 4 outputs compliant mechanism is obtained by using the method, and the corresponding micro-positioning stage system is further designed.

关键词： Topology optimization Compliant mechanisms Micro-positioning

Preload characteristics identification of the piezoelectric- actuated 1-DOF compliant nanopositioning platform

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Frontiers of Mechanical Engineering 2015年第1期10卷 20-36页

作者： Ruizhou WANG xianmin zhang School of Mechanical and Automotive Engineering South ChinaUniversity of Technology Guangzhou 510641 China

Packaged piezoelectric ceramic actuators （PPCAs） and compliant mechanisms are attractive for nanopositioning and nanomanipulation due to their ultra- high precision. The way to create and keep a proper and steady connection between both ends of the PPCA and the compliant mechanism is an essential step to achieve such a high accuracy. The connection status affects the initial position of the terminal moving plate, the positioning accuracy and the dynamic performance of the nanoposi- tioning platform, especially during a long-time or high- frequency positioning procedure. This paper presents a novel external preload mechanism and tests it in a 1-degree of freedom （I-DOF） compliant nanopositioning platform. The 1-DOF platform utilizes a parallelogram guiding mechanism and a parallelogram load mechanism to provide a more accurate actual input displacement and output displacement. The proposed stiffness model simulation results verify the and dynamic model of the platform. The values of the preload displacement, actual input displacement and output displacement can be measured by three capacitive sensors during the whole positioning procedure. The test results show the preload characteristics vary with different types or control modes of the PPCA. Some fitting formulas are derived to describe the preload displacement, actual input displacement and output displacement using the nominal elongation signal of the PPCA. With the identification of the preload characteristics, the actual and comprehensive output characteristics of the PPCA can be obtained by the strain gauge sensor （SGS） embedded in the PPCA.

关键词： nanoposifioning preload characteristic pack-aged piezoelectric ceramic actuator compliant mechanism

Resistive switching and artificial synaptic performances of memristor based on low-dimensional bismuth halide perovskites

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Nano Research 2023年第7期16卷 10108-10119页

作者： Feifei Luo Yanzhao Wu Junwei Tong Fubo Tian xianmin zhang Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Department of Physics Freie Universität Berlin14195 BerlinGermany State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Zero-dimensional(0D)-Cs_(3)Bi_(2)I_(9),two-dimensional(2D)-Cs_(3)Bi_(2)Br_(9),and one-dimensional(1D)-Cs3Bi2Cl9 perovskite films have been successfully grown on indium tin oxide(ITO)glass substrates,which were used to fabricate memristors with the structure of Al/Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)/ITO *** current three types of memristors exhibited bipolar resistive switching *** the endurance and retention time tests clearly demonstrated the excellent stability of present ***,the ON/OFF ratio of the 0D-Cs_(3)Bi_(2)I_(9)device is close to 104 at the reading voltage of 0.1 V,which is nearly 100 and 1000 times larger than those of the 1D-Cs3Bi2Cl9 device and the 2D-Cs_(3)Bi_(2)Br_(9)device,*** activation energy of halide vacancies in the Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)films was calculated using the density functional theory by considering a minimum migration path,demonstrating the dimensionality of the Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)film affected the formation and rupture of conductive ***,the short-term plasticity and long-term plasticity of biological synapse were simulated by evaluating the conductance responses of Al/Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)/ITO devices under various voltage pulses in *** duration time of long-term plasticity in all the present devices can last for up to 250 *** 0D-Cs_(3)Bi_(2)I_(9)device showed both the highest spikeduration-dependent plasticity and paired-pulse facilitation indexes compared to the other two ***,the 0DCs_(3)Bi_(2)I_(9)device successfully established the associative learning behavior by simulating the Pavlov’s dog experiment.

关键词： perovskite films low-dimension resistive switching artificial synapse

Topological and Shape Optimization of Flexure Hinges for Designing Compliant Mechanisms Using the Level Set Method

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Chinese Journal of Mechanical Engineering 2019年第1期32卷 42-53页

作者： Benliang Zhu xianmin zhang Min Liu Qi Chen Hai Li Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology South China University of Technology East China Jiaotong University

A flexure hinge is a major component in designing compliant mechanisms that o ers unique possibilities in a wide range of application fields in which high positioning accuracy is required. Although various flexure hinges with di erent configurations have been successively proposed, they are often designed based on designers' experiences and inspirations. This study presents a systematic method for topological optimization of flexure hinges by using the level set method. Optimization formulations are developed by considering the functional requirements and geometrical constraints of flexure hinges. The functional requirements are first constructed by maximizing the compliance in the desired direction while minimizing the compliances in the other directions. The weighting sum method is used to construct an objective function in which a self-adjust method is used to set the weighting factors. A constraint on the symmetry of the obtained configuration is developed. Several numerical examples are presented to demonstrate the validity of the proposed method. The obtained results reveal that the design of a flexure hinge starting from the topology level can yield more choices for compliant mechanism design and obtain better designs that achieve higher performance.

关键词： Topology optimization Compliant mechanisms Flexure hinges Level set method

Electrically manipulating magnetization reversal via energy band engineering

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Science China(Physics,Mechanics & Astronomy) 2023年第5期66卷 181-187页

作者： Junwei Tong Yanzhao Wu Feifei Luo Fubo Tian xianmin zhang Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China Department of Physics Freie Universität BerlinBerlin 14195Germany State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Realization of a magnetization reversal by an external electric field is vital for developing ultra-low-power spintronic *** this report,starting from energy band engineering,a general design principle is proposed for achieving electrical manipulation of a nonvolatile 180°magnetization reversal.A half semiconductor(HSC)and a bipolar magnetic semiconductor(BMS)are selected as the model of magnetic layers,whose conduction-band minimum and valence-band maximum are in the same and opposite spin states,*** on the analysis of virtual hopping and tight-binding models,the interlayer coupling of HSC/insulator/BMS devices is successfully tuned between ferromagnetic and antiferromagnetic interactions by varying electric field ***,the interlayer coupling nearly disappears after removing the electric field,proving the nonvolatile magnetization *** first-principles calculations,the feasibility of present design strategy is further confirmed by a representative device with the structure of CrBr3/h-BN/2H-VSe_(2).This design guideline and physical phenomena may open an avenue to explore magnetoelectric coupling mechanisms and develop next-generation spintronic devices.

关键词： magnetic semiconductor magnetization reversal energy band engineering

Advances in dielectric elastomer actuation technology

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Science China(Technological Sciences) 2018年第10期61卷 1512-1527页

作者： WANG NianFeng CUI ChaoYu GUO Hao CHEN BiCheng zhang xianmin Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology South China University of Technology

Dielectric elastomer actuators(DEAs) have attracted much interest over the past decades due to the inherent flexibility, large strain, high efficiency, high energy density, and fast response of the material, which are known as one of the most promising candidates for artificial muscle. In this paper, we first introduce the actuation principle and electromechanical modeling approaches of dielectric elastomers(DEs). Then, the performance of different DEs material and existing compliant electrodes that are widely utilized for DEAs are presented. We also highlight the compatibility of DEs, which is suitable for a variety of actuator designs and applications. Lastly, we summarize the challenges and future development in terms of electromechanical modeling, improvement of materials including compliant electrodes and dielectric elastomer, designs and applications of novel dielectric elastomer actuators.

关键词： dielectric elastomer electromechanical modeling compliant electrodes actuator