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Gained switching-based fuzzy sliding mode control for a discrete-time underactuated robotic system with

Hui LI, Ruiqin LI, Jianwei ZHANG

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 353-362 doi: 10.1007/s11465-020-0620-4

摘要： This study proposes a gained switching-based discrete-time sliding mode control method to address the chattering issue in disturbed discrete-time systems, which suffer from various unknown uncertainties. Through the new structure of the designed reaching law, the proposed method can effectively increase the convergence speed while guaranteeing chattering-free control. The performance of controlling underactuated robotic systems can be further improved by the adoption of fuzzy logic to perform adaptive online hyper-parameter tuning. In addition, an underactuated robotic system with uncertainties is studied to validate the effectiveness of the proposed reaching law. Results reveal the dynamic performance and robustness of the proposed reaching law in the studied system and prove the proposed method’s superiority over other state-of-the-art methods.

关键词： sliding-mode control     robot control     discrete-time uncertain systems     fuzzy logic    

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Frequencies of circular plate with concentric ring and elastic edge support

null

《机械工程前沿（英文）》 2014年 第9卷 第2期   页码 168-176 doi: 10.1007/s11465-014-0299-5

摘要：

Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution.

关键词： circular plate     frequency     elastic edge     rigid ring     mode switching    

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Fundamental buckling of circular plates with elastically restrained edges and resting on concentric rigid ring support

Lokavarapu Bhaskara Rao, Chellapilla Kameswara Rao

《机械工程前沿（英文）》 2013年 第8卷 第3期   页码 291-297 doi: 10.1007/s11465-013-0255-9

摘要：

This work presents the existence of buckling mode switching with respect to the radius of concentric rigid ring support. The buckling mode may not be axisymmetric as previously assumed. In general, the plate may buckle in an axisymmetric mode but when the radius of the ring support becomes small, the plate may buckle in an asymmetric mode. The optimum radius of the concentric rigid ring support for maximum buckling load is also determined. Introducing internal rigid ring support, when placed at an optimal position increases the elastic buckling load capacity by 149.39 percent. The numerical results obtained are in good agreement with the previously published data.

关键词： buckling     circular plate     elastically restrained edge     rigid ring support     mode switching    

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Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

《机械工程前沿（英文）》 2011年 第6卷 第3期   页码 287-291 doi: 10.1007/s11465-011-0230-2

摘要：

The dynamic responses of ferroelectric materials upon external mechanical and electrical stimulations are inherently nonlinear and coupled. In the current paper, a macroscopic differential model is constructed for the coupled hysteretic dynamics via modeling the orientation switching induced in the materials. A non-convex potential energy is constructed with both mechanic and electric field contributions. The governing equations are formulated as nonlinear ordinary differential equations by employing the Euler-Lagrange equation, and can be easily recast into a state space form. Hysteresis loops associated with stress induced polarization switching and butterfly-shaped behavior in ferroelectric materials are also successfully captured. The effects of mechanical loadings on the electrically induced switching are numerically investigated, as well as the mechanically-induced switching with various bias electric fields.

关键词： differential model     state space     electromechanical switching     butterfly effects     hysteresis    

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Experimental investigation of a novel micro gas turbine with flexible switching function for distributed

Xiaojing LV, Weilun ZENG, Xiaoyi DING, Yiwu WENG, Shilie WENG

《能源前沿（英文）》 2020年 第14卷 第4期   页码 790-800 doi: 10.1007/s11708-020-0691-2

摘要： Micro gas turbine (MGT) is widely used in small-scale distributed power systems because of its low emissions and fuel flexibility. However, the under-utilization of its exhaust heat and the low electric efficiency are the main bottlenecks that restrict its application. Additionally, the flexible switching between the power generated by the MGT and the power grid is also a key factor for keeping the secure operation of a distributed power station. Therefore, this paper conducted some experimental investigations of a 30 kW MGT to provide reference solutions for the above issues. This MGT is located at Shanghai Jiao Tong University (SJTU), which is designed by the Gas Turbine Research Institute of SJTU, and is manufactured by a turbo-machinery factory in Chongqing, China. The demonstration prototype is mainly composed of a single stage centrifugal compressor, a radial turbine, a combustor, a high-speed permanent magnet generator, and a control system. The results show that the MGT can achieve steady operation at a low rotational speed from 10000 r/min to 34000 r/min in the case of using oil lubricated bearings, which can greatly reduce the economic cost compared with the use of air bearings. At the same time, the ignition success rate of combustion chamber (CC) reaches 98% at a low rotational speed, and a wide range of stable combustion area can be obtained, because of the novel design method of combustor by referencing the way applied in an axial flow aero-engine. The MGT generating set can achieve functions, such as starting up, ignition, stable operation, loaded operation, grid-connection and stopping. This system also can realize flexibly switching from the start motor mode to the generator mode, and from grid-connected mode to off-grid mode, because the innovative multi-state switching control system is adopted. The above research work can make our state master independent intellectual property rights of micro gas turbine, rather than continue to be subject to the technological monopoly of the developed states, which can provide theoretical and experimental support for the industrialization of MGT in China.

关键词： gas turbine     flexible switching system     control system     distributed power system     emission test    

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An improved delta-star switching scheme for reactive power saving in three-phase induction motors

P. RAJA,N. KUMARESAN,M. SUBBIAH

《能源前沿（英文）》 2014年 第8卷 第3期   页码 364-370 doi: 10.1007/s11708-014-0324-8

摘要： It is proposed that a capacitor can be connected permanently across each phase winding of a three-phase induction motor along with the conventional delta-star switching, for further saving in VARh at reduced loads on the motor. The method of choosing a suitable value for the capacitor and the criteria to be adopted for calculating the power output at which the star to delta switching is to be made are also explained. The experimental results on a 3-phase, 4-pole, 415 V, 50 Hz, 3.3 kW induction motor verify the advantages in adding the capacitor to the phase winding of the motor. Compared to using only a single delta connected stator winding or a delta-star switching, the advantages of the proposed addition of a capacitor, are also demonstrated through a case study conducted on a 400 V, 250 kW motor. Any further improvement in grid side power factor can be achieved by employing a static synchronous compensator (STATCOM) of reduced VAR rating.

关键词： delta-star switching     induction motor     power factor     steady-state analysis    

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A novel soft-switching twin arc pulse MAG welding inverter

WANG Zhenmin, XUE Jiaxiang, WANG Fuguang, HUANG Shisheng

《机械工程前沿（英文）》 2007年 第2卷 第2期   页码 224-227 doi: 10.1007/s11465-007-0039-1

摘要： The high-speed double wire pulse metal gas arc (MAG) welding process possesses advantages of automation and high efficiency and quality. Thus, it attracts much more attention nowadays. To meet the requirements of the double wire pulse MAG welding process, a novel double wire pulse MAG welding inverter integrated with technologies, such as soft-switching, double closed loop control, and synchronic control, is produced. A complete performance test was done for the pulsed MAG welding power supply by using a computer testing platform. The results of the experiment indicate that the novel welding inverter has an excellent performance both in the dynamic and the static characteristics. Also, the synchronic control between the master inverter and the slave inverter is reliable.

关键词： high-speed     control     computer     experiment indicate     platform    

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国内首台ATM交换机研制及其组网实践

雷振明

《中国工程科学》 2000年 第2卷 第2期   页码 53-55

摘要：

国内首台ATM（异步转送方式）交换机BTC-9500的研制于1995年完成，并配合国内宽带试验网络的建设，进行了大量的组网试验、设计改进和发展工作。目前，该设备已经由国内最大的电信设备制造商之一——上海贝尔公司生产销售，并且用于装备中国电信宽带骨干网的全部核心节点。根据组网实践中发现的问题，提出了在同一个交换结构内同时实现ATM信元交换和IP数据报交换的方案，并在BTC-9500中予以实现，达到了大大节省设备、简化网络和提高网络速度的多重目的，将研究范围逐渐拓宽到更大的宽带通信领域，提出了对于新一代电信网络发展的一些看法。

关键词： 通信     交换     异步转送方式（ATM）    

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A pulsed switching peroxi-coagulation process to control hydroxyl radical production and to enhance 2,4

Yaobin Lu, Songli He, Dantong Wang, Siyuan Luo, Aiping Liu, Haiping Luo, Guangli Liu, Renduo Zhang

《环境科学与工程前沿（英文）》 2018年 第12卷 第5期 doi: 10.1007/s11783-018-1070-7

摘要：

• A new pulsed switching peroxi-coagulation (PSPC) system was developed.

• The ECT for 2,4-D removal in the PSPC was lower than that in the EF.

• The iron consumption for 2,4-D removal in the PSPC was lower than that in the PC.

关键词： Pulsed switching peroxi-coagulation system     Energy consumption     Hydroxyl radical production     2     4- Dichlorophenoxyacetic acid    

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Performance monitoring of non-gaussian chemical processes with modes-switching using globality-locality

Xin Peng, Yang Tang, Wenli Du, Feng Qian

《化学科学与工程前沿（英文）》 2017年 第11卷 第3期   页码 429-439 doi: 10.1007/s11705-017-1675-6

摘要： In this paper, we propose a novel performance monitoring and fault detection method, which is based on modified structure analysis and globality and locality preserving (MSAGL) projection, for non-Gaussian processes with multiple operation conditions. By using locality preserving projection to analyze the embedding geometrical manifold and extracting the non-Gaussian features by independent component analysis, MSAGL preserves both the global and local structures of the data simultaneously. Furthermore, the tradeoff parameter of MSAGL is tuned adaptively in order to find the projection direction optimal for revealing the hidden structural information. The validity and effectiveness of this approach are illustrated by applying the proposed technique to the Tennessee Eastman process simulation under multiple operation conditions. The results demonstrate the advantages of the proposed method over conventional eigendecomposition-based monitoring methods.

关键词： non-Gaussian processes     subspace projection     independent component analysis     locality preserving projection     finite mixture model    

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基于异步切换和可容许边依赖平均驻留时间方法的切换线性系统镇定研究 Research Article

侯林林1,马萱1,孙海滨2

《信息与电子工程前沿（英文）》 2022年 第23卷 第5期   页码 810-822 doi: 10.1631/FITEE.2000698

摘要： 本文研究异步切换条件下切换线性系统的镇定问题。采用可容许边依赖平均驻留时间方法，设计包含慢可容许边依赖平均驻留时间和快可容许边依赖平均驻留时间的切换信号。这种切换信号设计方法消除了异步切换最大延迟事先已知的限制。构造的李雅普诺夫函数与系统模态和控制器模态均相关。给出了获取控制器增益和设计切换信号的稳定性准则及相应算法。最后，通过两个算例验证了所提结果的有效性。

关键词： 异步切换；可容许边依赖平均驻留时间；多李雅普诺夫函数    

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Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode

Abdelkarim AMMAR,Amor BOUREK,Abdelhamid BENAKCHA

《能源前沿（英文）》 2020年 第14卷 第4期   页码 836-849 doi: 10.1007/s11708-017-0444-z

摘要： This paper proposes a design of control and estimation strategy for induction motor based on the variable structure approach. It describes a coupling of sliding mode direct torque control (DTC) with sliding mode flux and speed observer. This algorithm uses direct torque control basics and the sliding mode approach. A robust electromagnetic torque and flux controllers are designed to overcome the conventional SVM-DTC drawbacks and to ensure fast response and full reference tracking with desired dynamic behavior and low ripple level. The sliding mode controller is used to generate reference voltages in stationary frame and give them to the controlled motor after modulation by a space vector modulation (SVM) inverter. The second aim of this paper is to design a sliding mode speed/flux observer which can improve the control performances by using a sensorless algorithm to get an accurate estimation, and consequently, increase the reliability of the system and decrease the cost of using sensors. The effectiveness of the whole composed control algorithm is investigated in different robustness tests with simulation using Matlab/Simulink and verified by real time experimental implementation based on dS pace 1104 board.

关键词： induction motor     direct torque control (DTC)     space vector modulation (SVM)     sliding mode control (SMC)     sliding mode observer (SMO)     dS1104    

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基于双重分组和密钥计数的并行认证模式

黄玉划,胡爱群,宋宇波

《中国工程科学》 2004年 第6卷 第7期   页码 70-74

摘要：

由于CBC－MAC模式不可并行处理，提出了一种基于双重分组的并行认证模式(PKCB)。PKCB模式同并行认证模式PMAC相比，安全性和速率都有显著提高，PKCB认证模式与CTR（计数器）加密模式结合可构成分组密码算法的一种全工作模式。在此基础上提出了一种基于密钥计数的并行认证模式（KCTR－MAC）。KCTR－MAC模式安全性比PMAC模式高得多，而速率未降低，KCTR－MAC认证模式和CTR加密模式结合也可构成分组密码算法的一种全工作模式（2CTR），2CTR模式的综合性能不亚于标准模式CCM（CTR with CBC－MAC），是一种安全快速的实用模式。

关键词： 认证模式     CBC－MAC模式     PMAC模式     CTR模式     CCM模式    

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Probabilistic stability of uncertain composite plates and stochastic irregularity in their buckling mode

《结构与土木工程前沿（英文）》   页码 179-190 doi: 10.1007/s11709-022-0888-z

摘要： In this study, the mechanical properties of the composite plate were considered Gaussian random fields and their effects on the buckling load and corresponding mode shapes were studied by developing a semi-analytical non-intrusive approach. The random fields were decomposed by the Karhunen−Loève method. The strains were defined based on the assumptions of the first-order and higher-order shear-deformation theories. Stochastic equations of motion were extracted using Euler–Lagrange equations. The probabilistic response space was obtained by employing the non-intrusive polynomial chaos method. Finally, the effect of spatially varying stochastic properties on the critical load of the plate and the irregularity of buckling mode shapes and their sequences were studied for the first time. Our findings showed that different shear deformation plate theories could significantly influence the reliability of thicker plates under compressive loading. It is suggested that a linear relationship exists between the mechanical properties’ variation coefficient and critical loads’ variation coefficient. Also, in modeling the plate properties as random fields, a significant stochastic irregularity is obtained in buckling mode shapes, which is crucial in practical applications.

关键词： uncertain composite plate     stochastic assume mode method     Karhunen−Loève theorem     polynomial chaos approach     plate buckling     irregularity in buckling mode shapes    

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Experimental investigation of evolutive mode-I and mode-II fracture behavior of fiber-reinforced cemented

《结构与土木工程前沿（英文）》 2023年 第17卷 第2期   页码 256-270 doi: 10.1007/s11709-022-0924-z

摘要： The curing temperature-dependent cement hydration causes the nonlinear evolution of fracture behavior and properties of fiber-reinforced cemented paste backfill (CPB) and thus influences the stability of mine backfill materials in deep mines. Therefore, the coupled effect of curing temperature (20, 35, and 45 °C) and cement hydration at different curing times (3, 7, and 28 d) on the mode-I and mode-II fracture behavior and properties of fiber-reinforced CPB is investigated. A comprehensive experimental testing program consisting of semicircular bend tests, direct shear tests, measurement of volumetric water content and matric suction, TG/DTG tests, and SEM observation is carried out. The results show that the coupled thermochemical effect results in strongly nonlinear development of pre- and post-peak behavior of fiber-reinforced CPB. Moreover, the results discover a positive linear correlation between fracture toughness and shear strength parameters and also reveal the vital role played by matric suction in the formation of fracture toughness. Furthermore, predictive functions are developed to estimate the coupled thermochemical effect on the development of KIc and KIIc. Therefore, the findings and the developed mathematical tools have the potential to promote the successful application of fiber-reinforced CPB technology in deep underground mines.

关键词： fiber reinforcement     cemented paste backfill     fracture behavior     underground mine     cement hydration    

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标题 作者 时间 类型 操作

Gained switching-based fuzzy sliding mode control for a discrete-time underactuated robotic system with

Hui LI, Ruiqin LI, Jianwei ZHANG

期刊论文

Frequencies of circular plate with concentric ring and elastic edge support

null

期刊论文

Fundamental buckling of circular plates with elastically restrained edges and resting on concentric rigid ring support

Lokavarapu Bhaskara Rao, Chellapilla Kameswara Rao

期刊论文

Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

期刊论文

Experimental investigation of a novel micro gas turbine with flexible switching function for distributed

Xiaojing LV, Weilun ZENG, Xiaoyi DING, Yiwu WENG, Shilie WENG

期刊论文

An improved delta-star switching scheme for reactive power saving in three-phase induction motors

P. RAJA,N. KUMARESAN,M. SUBBIAH

期刊论文

A novel soft-switching twin arc pulse MAG welding inverter

WANG Zhenmin, XUE Jiaxiang, WANG Fuguang, HUANG Shisheng

期刊论文

国内首台ATM交换机研制及其组网实践

雷振明

期刊论文

A pulsed switching peroxi-coagulation process to control hydroxyl radical production and to enhance 2,4

Yaobin Lu, Songli He, Dantong Wang, Siyuan Luo, Aiping Liu, Haiping Luo, Guangli Liu, Renduo Zhang

期刊论文

Performance monitoring of non-gaussian chemical processes with modes-switching using globality-locality

Xin Peng, Yang Tang, Wenli Du, Feng Qian

期刊论文

基于异步切换和可容许边依赖平均驻留时间方法的切换线性系统镇定研究

侯林林1,马萱1,孙海滨2

期刊论文

Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode

Abdelkarim AMMAR,Amor BOUREK,Abdelhamid BENAKCHA

期刊论文

基于双重分组和密钥计数的并行认证模式

黄玉划,胡爱群,宋宇波

期刊论文

Probabilistic stability of uncertain composite plates and stochastic irregularity in their buckling mode

期刊论文

Experimental investigation of evolutive mode-I and mode-II fracture behavior of fiber-reinforced cemented

期刊论文