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期刊论文 49

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关键词

反馈线性化 2

正反馈 2

蚁群算法 2

解耦控制 2

Lipschitz非线性系统;动态输出反馈控制;事件触发控制;全局渐近稳定 1

三维毛笔模型;三维笔道;三维交互绘制;实时力反馈技术 1

交互反馈 1

人工智能 1

优化 1

传感器 1

信息素 1

先天性心脏病 1

分布式人工智能云端平台 1

前馈神经网络(FFNN) 1

前馈补偿器 1

力反馈手套 1

力矩反馈器 1

动态输出反馈 1

反馈式设计 1

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Multiscale computation on feedforward neural network and recurrent neural network

Bin LI, Xiaoying ZHUANG

《结构与土木工程前沿(英文)》 2020年 第14卷 第6期   页码 1285-1298 doi: 10.1007/s11709-020-0691-7

摘要: Homogenization methods can be used to predict the effective macroscopic properties of materials that are heterogenous at micro- or fine-scale. Among existing methods for homogenization, computational homogenization is widely used in multiscale analyses of structures and materials. Conventional computational homogenization suffers from long computing times, which substantially limits its application in analyzing engineering problems. The neural networks can be used to construct fully decoupled approaches in nonlinear multiscale methods by mapping macroscopic loading and microscopic response. Computational homogenization methods for nonlinear material and implementation of offline multiscale computation are studied to generate data set. This article intends to model the multiscale constitution using feedforward neural network (FNN) and recurrent neural network (RNN), and appropriate set of loading paths are selected to effectively predict the materials behavior along unknown paths. Applications to two-dimensional multiscale analysis are tested and discussed in detail.

关键词: multiscale method     constitutive model     feedforward neural network     recurrent neural network    

记忆成像 Article

方璐, 季梦奇, 袁肖赟, 贺敬, 张嘉凝, 朱胤恒, 郑添, 刘乐遥, 王滨, 戴琼海

《工程(英文)》 2023年 第25卷 第6期   页码 101-109 doi: 10.1016/j.eng.2021.12.012

摘要:

Sensing and understanding large-scale dynamic scenes require a high-performance imaging system. Conventional imaging systems pursue higher capability by simply increasing the pixel resolution via stitching cameras at the expense of a bulky system. Moreover, they strictly follow the feedforward pathway: that is, their pixel-level sensing is independent of semantic understanding. Differently, a human visual system owns superiority with both feedforward and feedback pathways: The feedforward pathway extracts object representation (referred to as memory engram) from visual inputs, while, in the feedback pathway, the associated engram is reactivated to generate hypotheses about an object. Inspired by this, we propose a dual-pathway imaging mechanism, called engram-driven videography. We start by abstracting the holistic representation of the scene, which is associated bidirectionally with local details, driven by an instance-level engram. Technically, the entire system works by alternating between the excitation–inhibition and association states. In the former state, pixel-level details become dynamically consolidated or inhibited to strengthen the instance-level engram. In the association state, the spatially and temporally consistent content becomes synthesized driven by its engram for outstanding videography quality of future scenes. The association state serves as the imaging of future scenes by synthesizing spatially and temporally consistent content driven by its engram. Results of extensive simulations and experiments demonstrate that the proposed system revolutionizes the conventional videography paradigm and shows great potential for videography of large-scale scenes with multi-objects.

关键词: Instance-level videography     Memory engram     Large-scale dynamic scene     Feedforward and feedback     Entropy equilibrium    

面向CPG驱动的仿生机器鱼容错控制方法 Article

杨越麒, 王健, 吴正兴, 喻俊志

《工程(英文)》 2018年 第4卷 第6期   页码 861-868 doi: 10.1016/j.eng.2018.09.011

摘要:

容错性能对于自推进仿生机器鱼在实际水下应用中的可操作性和生存能力至关重要。本文探讨了具有多个可活动关节和一个被卡住尾部关节的自由游动机器鱼的容错控制问题。提出的控制系统主要由两个部分组成:反馈控制器和前馈补偿器。具体而言,一方面,设计了基于生物启发中心模式发生器的反馈控制器用于使机器鱼对外部干扰具有鲁棒性;另一方面,引入了基于动力学模型的前馈补偿器来加速整个控制系统的收敛。在此基础上,开展了仿真实验来完成控制系统分析和故障机器鱼游动性能验证。最后,水下实验表明,所提出的容错控制方法能够有效调整故障机器鱼,使其能够在故障情况下完成所需运动,进而提高实际机器鱼系统的稳定性和寿命。

关键词: 容错控制     机器鱼     运动控制     反馈控制器     前馈补偿器    

An autonomous miniature wheeled robot based on visual feedback control

CHEN Haichu

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 197-200 doi: 10.1007/s11465-007-0033-7

摘要: Using two micro-motors, a novel omni-direction miniature wheeled robot is designed on the basis of the bi-corner driving principle. The robot takes advantage of the Bluetooth technology to wirelessly transmit data at a short distance. Its position and omni-direction motion are precise. A Charge Coupled Device (CCD) camera is used for measuring and for visual navi gation. A control system is developed. The precision of the position is 0.5 mm, the resolution is about 0.05 mm, and the maximum velocity is about 52 mm/s. The visual navigation and control system allow the robot to navigate and track the target and to accomplish autonomous locomotion.

关键词: measuring     distance     autonomous locomotion     advantage     navigation    

Tracking control of robot manipulators via output feedback linearization

FEI Yue-nong, Wu Qing-hua

《机械工程前沿(英文)》 2006年 第1卷 第3期   页码 329-335 doi: 10.1007/s11465-006-0034-y

摘要: This paper presents a robot manipulator tracking controller based on output feedback linearization. A sliding mode perturbation observer (SPO) is designed to estimate unmeasurable states and system perturbations that involve system nonlinearities, disturbances and unmodelled dynamics. The use of SPO allows to input/output linearize and decouple the strongly coupled nonlinear robot manipulator system merely by the feedback of joint angles. The controller design does not need an accurate model of the robot manipulator. Simulation studies are undertaken based on a two-link robot manipulator to evaluate the proposed approach. The simulation results show that the proposed controller has more superior tracking control performance, with payload changing in a wide range, in comparison with a sliding mode controller (SMC) designed based on state feedback linearization with full states available.

关键词: available     comparison     unmeasurable     nonlinear     perturbation observer    

Feedback linearization based control for weak grid connected PV system under normal and abnormal conditions

Rahul SHARMA,Sathans SUHAG

《能源前沿(英文)》 2020年 第14卷 第2期   页码 400-409 doi: 10.1007/s11708-017-0459-5

摘要: This paper proposes a control strategy for interface of distributed energy sources into the weak grid system with a focus on the energy and ancillary services. A novel controller has been designed and implemented to tackle the challenges of coupling terms in the LCL filter, the transient behavior under sudden changes, and the voltage support under fault condition using the feedback linearization technique. The controller proposed has been implemented on the PV system connected with the weak grid using the LCL filter and the performance of the controller has been verified using Matlab/Simulink through simulation under different conditions. The results of the controller proposed have been compared with the conventional PI dual loop controller. The simulation results obtained demonstrate the effectiveness and simplicity of the controller design strategy.

关键词: PV system     grid interface     feedback linearization     inverter     LCL filter    

Feedforward control for nitrogen removal in a pilot-scale anaerobic-anoxic-oxic plant for municipal wastewater

Tonggang SHEN, Hanchang SHI, Huiming SHI, He JING, Huilei XIONG

《环境科学与工程前沿(英文)》 2011年 第5卷 第1期   页码 130-139 doi: 10.1007/s11783-010-0266-2

摘要: To improve the efficiency of nitrogen removal with lower energy consumption, the study of feedforward control was carried out on a pilot-scale anaerobic-anoxic-oxic (AAO) plant for the treatment of municipal wastewater. The effluent qualities of the pilot plant under different control strategies were investigated. The results indicated that the change of external recycle was not a suitable approach to regulate the sludge concentration of plug-flow reactors; adjusting the aeration valve and dissolved oxygen set-point according to ammonia load could overcome the impact of influent fluctuation; and the denitrification potential could be estimated based on the transit time of anoxic zone and the relative content of carbon resource entering the anoxic zone. Simple feedforward control strategies for aeration and internal recycle were subsequently proposed and validated. The nitrogen removal was successfully improved in the pilot plant. The effluent total nitrogen had decreased by 29.9% and was steadily controlled below 15 mg·L . Furthermore, approximately 38% of the energy for aeration had been saved.

关键词: anaerobic-anoxic-oxic (AAO)     feedforward control     municipal wastewater     nitrogen removal    

A combined modulated feedback and temperature compensation approach to improve bias drift of a closed-loop

Ming-jun MA,Zhong-he JIN,Hui-jie ZHU

《信息与电子工程前沿(英文)》 2015年 第16卷 第6期   页码 497-510 doi: 10.1631/FITEE.1400349

摘要: The bias drift of a micro-electro-mechanical systems (MEMS) accelerometer suffers from the 1/ noise and the temperature effect. For massive applications, the bias drift urgently needs to be improved. Conventional methods often cannot address the 1/ noise and temperature effect in one architecture. In this paper, a combined approach on closed-loop architecture modification is proposed to minimize the bias drift. The modulated feedback approach is used to isolate the 1/ noise that exists in the conventional direct feedback approach. Then a common mode signal is created and added into the closed loop on the basis of modulated feedback architecture, to compensate for the temperature drift. With the combined approach, the bias instability is improved to less than 13 μ , and the drift of the Allan variance result is reduced to 17 μ at 100 s of the integration time. The temperature coefficient is reduced from 4.68 to 0.1 m /°C. The combined approach could be useful for many other closed-loop accelerometers.

关键词: Bias drift     Closed-loop MEMS accelerometer     Modulated feedback approach     Temperature compensation    

Topology optimization of piezoelectric bi-material actuators with velocity feedback control

Mariana MORETTI, Emílio C. N. SILVA

《机械工程前沿(英文)》 2019年 第14卷 第2期   页码 190-200 doi: 10.1007/s11465-019-0537-y

摘要: In recent years, the new technologies and discoveries on manufacturing materials have encouraged researchers to investigate the appearance of material properties that are not naturally available. Materials featuring a specific stiffness, or structures that combine non-structural and structural functions are applied in the aerospace, electronics and medical industry fields. Particularly, structures designed for dynamic actuation with reduced vibration response are the focus of this work. The bi-material and multifunctional concepts are considered for the design of a controlled piezoelectric actuator with vibration suppression by means of the topology optimization method (TOM). The bi-material piezoelectric actuator (BPEA) has its metallic host layer designed by the TOM, which defines the structural function, and the electric function is given by two piezo-ceramic layers that act as a sensor and an actuator coupled with a constant gain active velocity feedback control (AVFC). The AVFC, provided by the piezoelectric layers, affects the structural damping of the system through the velocity state variables readings in time domain. The dynamic equation analyzed throughout the optimization procedure is fully elaborated and implemented. The dynamic response for the rectangular four-noded FE analysis is obtained by the Newmark’s time-integration method, which is applied to the physical and the adjoint systems, given that the adjoint formulation is needed for the sensitivity analysis. A gradient-based optimization method is applied to minimize the displacement energy output measured at a predefined degree-of-freedom of the BPEA when a transient mechanical load is applied. Results are obtained for different control gain values to evaluate their influence on the final topology.

关键词: topology optimization method     bi-material piezoactuator     active velocity feedback control     time-domain transient analysis     host structure design     vibration suppression    

Applications of the crystallization process in the pharmaceutical industry

Sohrab ROHANI

《化学科学与工程前沿(英文)》 2010年 第4卷 第1期   页码 2-9 doi: 10.1007/s11705-009-0297-z

摘要: The applications of the crystallization technique in the pharmaceutical industry as a purification and separation process for the isolation and synthesis of pure active pharmaceutical ingredients (API), co-crystals, controlled release pulmonary drug delivery, and separation of chiral isomers are briefly discussed using a few case studies. The effect of process variables and solvent on the polymorphism and morphology of stavudine is discussed. The implementation of external control in the form of feedback and real-time optimal control using cooling and antisolvent crystallization of paracetamol in water-isopropyl alcohol is introduced. Two methods to prepare micron-sized drug particles, namely, micro-crystallization and polymer-coated API-loaded magnetic nanoparticles for pulmonary drug delivery, are discussed. The significance of co-crystals in drug administration is highlighted using the theophylline-nicotinamide co-crystal system. Resolution of chloromandelic acid derivatives, a racemic compound, is achieved using direct crystallization and diastereomeric salts crystallization. The crystal structures of diastereomeric salts of chloromandelic acid and phenylethylamine are determined. The structure comparison between the less soluble and more soluble salts shows that weak interactions such as CH/π interactions and van der Waals forces contribute to chiral recognition when the hydrogen bonding patterns are similar.

关键词: feedback     morphology     pulmonary     paracetamol     recognition    

Constant temperature control of tundish induction heating power supply for metallurgical manufacturing

Yufei YUE, Qianming XU, Peng GUO, An LUO

《能源前沿(英文)》 2019年 第13卷 第1期   页码 16-26 doi: 10.1007/s11708-018-0572-0

摘要: The tundish induction heating power supply (TIHPS) is one of the most important equipment in the continuous casting process for metallurgical manufacturing. Specially, the constant temperature control is greatly significant for metallurgical manufacturing. In terms of the relationship between TIH load temperature and output power of TIHPS, the constant temperature control can be realized by power control. In this paper, a TIHPS structure with three-phase PWM rectifiers and full-bridge cascaded inverter is proposed. Besides, an input harmonic current blocking strategy and a load voltage feedforward control are also proposed to realize constant temperature control. To meet the requirement of the system, controller parameters are designed properly. Experiments are conducted to validate the feasibility and effectiveness of the proposed TIHPS topology and the control methods.

关键词: tundish induction heating power supply (TIHPS)     constant temperature control     input harmonic current blocking     load voltage feedforward    

非理想条件下空分复用研究与应用 None

Ji-ying XIANG

《信息与电子工程前沿(英文)》 2018年 第19卷 第3期   页码 357-366 doi: 10.1631/FITEE.1700827

摘要: 对空分复用技术中的非理想因素进行了理论分析,并探讨了在上述非理想工程条件下空分复用的应用,给出了实测数据。对于信道条件非理想的场景,即多通道之间相关性高,条件数大,导致高层间干扰,需要通过最优化用户匹配和降维达到最优容量。对于信道测量非理想的场景,深入分析了反馈式和非反馈式的优劣,并指出即使信道不满足互易性条件,非反馈式也是优选方法。针对上述问题,进行了理论分析和外场实测。

关键词: 第五代移动通讯;条件数;信道互易性;信道反馈测量模式;信道非反馈式测量模式    

Robust nonlinear control via feedback linearization and Lyapunov theory for permanent magnet synchronous

Ridha CHEIKH, Arezki MENACER, L. CHRIFI-ALAOUI, Said DRID

《能源前沿(英文)》 2020年 第14卷 第1期   页码 180-191 doi: 10.1007/s11708-018-0537-3

摘要: In this paper, the method for the nonlinear control design of a permanent magnet synchronous generator based-wind energy conversion system (WECS) is proposed in order to obtain robustness against disturbances and harvest a maximum power from a typical stochastic wind environment. The technique overcomes both the problem of nonlinearity and the uncertainty of the parameter compared to such classical control designs based on traditional control techniques. The method is based on the differential geometric feedback linearization technique (DGT) and the Lyapunov theory. The results obtained show the effectiveness and performance of the proposed approach.

关键词: permanent magnet synchronous generator     wind energy conversion system     stochastic     differential geometric     feedback linearization     maximum power point tracking     Lyapunov     robust control    

具有极点区域约束的广义模糊系统的输出反馈控制

高丹,曹媛媛

《中国工程科学》 2006年 第8卷 第4期   页码 63-67

摘要:

针对模糊广义系统,将动态输出反馈控制器设计问题转化为一组矩阵不等式的可行解问题,使得闭环系统不仅具有鲁棒性能,而且能把闭环系统极点配置在一个给定的圆形区域内,从而保证系统具有期望的动态性能。

关键词: 模糊广义系统     动态输出反馈     线性矩阵不等式    

一种具有大工作空间的轻量级力反馈手套 Article

郑宇铠, 王党校, 王子琦, 张昱, 张玉茹, 徐卫良

《工程(英文)》 2018年 第4卷 第6期   页码 869-880 doi: 10.1016/j.eng.2018.10.003

摘要:

在虚拟现实场景中,佩戴力反馈手套是一种有效的增强穿戴者与虚拟物体交互沉浸感的方法。这种手套的设计难点在于需要提供足够大的手指运动工作空间,在模拟自由空间和约束空间交互时提供所需的力反馈感觉,以及确保一个轻量级的结构。本文提出了一种将气动驱动器安装在使用者手背侧的力反馈手套。该手套采用了一种凸轮连杆组合机构,利用带有弯曲滑槽和三个运动副的连杆将阻力从气缸活塞杆传递到指尖。为了得到穿戴者指尖反馈力的一个较大的法向分量,通过分析带有三个运动副的连杆上的力平衡,计算出了滑槽的轮廓。本文研制了质量为245 g 的五指力反馈手套样机,建立了可穿戴的力测量系统,对自由空间和约束空间的力反馈性能进行了定量评价。实验结果表明,该手套在自由空间模拟中平均阻力小于0.1 N,在约束空间模拟中指尖力最大为4 N。实验进一步证实,这种手套能够保证手指的自由移动以及模拟典型的抓取操作手势。

关键词: 力反馈手套     轻量级     大工作空间     气压驱动     虚拟现实    

标题 作者 时间 类型 操作

Multiscale computation on feedforward neural network and recurrent neural network

Bin LI, Xiaoying ZHUANG

期刊论文

记忆成像

方璐, 季梦奇, 袁肖赟, 贺敬, 张嘉凝, 朱胤恒, 郑添, 刘乐遥, 王滨, 戴琼海

期刊论文

面向CPG驱动的仿生机器鱼容错控制方法

杨越麒, 王健, 吴正兴, 喻俊志

期刊论文

An autonomous miniature wheeled robot based on visual feedback control

CHEN Haichu

期刊论文

Tracking control of robot manipulators via output feedback linearization

FEI Yue-nong, Wu Qing-hua

期刊论文

Feedback linearization based control for weak grid connected PV system under normal and abnormal conditions

Rahul SHARMA,Sathans SUHAG

期刊论文

Feedforward control for nitrogen removal in a pilot-scale anaerobic-anoxic-oxic plant for municipal wastewater

Tonggang SHEN, Hanchang SHI, Huiming SHI, He JING, Huilei XIONG

期刊论文

A combined modulated feedback and temperature compensation approach to improve bias drift of a closed-loop

Ming-jun MA,Zhong-he JIN,Hui-jie ZHU

期刊论文

Topology optimization of piezoelectric bi-material actuators with velocity feedback control

Mariana MORETTI, Emílio C. N. SILVA

期刊论文

Applications of the crystallization process in the pharmaceutical industry

Sohrab ROHANI

期刊论文

Constant temperature control of tundish induction heating power supply for metallurgical manufacturing

Yufei YUE, Qianming XU, Peng GUO, An LUO

期刊论文

非理想条件下空分复用研究与应用

Ji-ying XIANG

期刊论文

Robust nonlinear control via feedback linearization and Lyapunov theory for permanent magnet synchronous

Ridha CHEIKH, Arezki MENACER, L. CHRIFI-ALAOUI, Said DRID

期刊论文

具有极点区域约束的广义模糊系统的输出反馈控制

高丹,曹媛媛

期刊论文

一种具有大工作空间的轻量级力反馈手套

郑宇铠, 王党校, 王子琦, 张昱, 张玉茹, 徐卫良

期刊论文