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主动式队列管理；传输控制协议；往返时滞；史密斯预估器 1

多智能体；一致性；PID（Proportional-integral-derivative）控制；线性矩阵不等式 1

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Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 420-434 doi: 10.1007/s11465-020-0622-2

摘要： Pilot two-stage proportional valves are widely used in high-power hydraulic systems. For the purpose of improving the dynamic performance, reliability, and digitization of the traditional proportional valve, a novel two-stage proportional valve with a pilot digital flow distribution is proposed from the viewpoint of the dual nozzle-flapper valve’s working principle. In particular, the dual nozzle-flapper is decoupled by two high-speed on/off valves (HSVs). First, the working principle and mathematical model of the proposed valve are determined. Then, the influences of the control parameters (duty cycle and switching frequency) and structural parameters (fixed orifice’s diameter and main valve’s spring) on the main valve’s motion are analyzed on the basis of theory, simulation, and experiment. In addition, in optimizing the value of the fixed orifice’s diameter, a new design criterion that considers the maximum pressure sensitivity, flow controllability, and flow linearization is proposed to improve the balance between the effective displacement and the displacement fluctuation of the main valve. The new scheme is verified by simulations and experiments. Experimental results of the closed-loop displacement tracking have demonstrated that the delay time of the main valve is always within 3.5 ms under different working conditions, and the tracking error can be significantly reduced using the higher switching frequency. The amplitude–frequency experiments indicate that a ‒3 dB-frequency of the proposed valve can reach 9.5 Hz in the case of±50% full scale and 15 Hz in the case of 0%–50% full scale. The values can be further improved by increasing the flow rate of the pilot HSV.

关键词： two-stage proportional valve     digital flow distribution     high-speed on/off valve     position tracking characteristic     dynamic performance    

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Proportional directional valve based automatic steering system for tractors Project supported

Jin-yi LIU,Jing-quan TAN,En-rong MAO,Zheng-he SONG,Zhong-xiang ZHU

《信息与电子工程前沿（英文）》 2016年 第17卷 第5期   页码 458-464 doi: 10.1631/FITEE.1500172

摘要： Most automatic steering systems for large tractors are designed with hydraulic systems that run on either constant flow or constant pressure. Such designs are limited in adaptability and applicability. Moreover, their control valves can unload in the neutral position and eventually lead to serious hydraulic leakage over long operation periods. In response to the problems noted above, a multifunctional automatic hydraulic steering circuit is presented. The system design is composed of a 5-way-3- position proportional directional valve, two pilot-controlled check valves, a pressure-compensated directional valve, a pressurecompensated flow regulator valve, a load shuttle valve, and a check valve, among other components. It is adaptable to most open-center systems with constant flow supply and closed-center systems with load feedback. The design maintains the lowest pressure under load feedback and stays at the neutral position during unloading, thus meeting the requirements for steering. The steering controller is based on proportional-integral-derivative (PID) running on a 51-microcontroller-unit master control chip. An experimental platform is developed to establish the basic characteristics of the system subject to stepwise inputs and sinusoidal tracking. Test results show that the system design demonstrates excellent control accuracy, fast response, and negligible leak during long operation periods.

关键词： Automatic steering system     Hydraulic circuit     Proportional directional valve     Proportional-integral-derivative (PID) control    

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The coupling of sand with ZVI/oxidants achieved proportional and highly efficient removal of arsenic

Sana Ullah, Xuejun Guo, Xiaoyan Luo, Xiangyuan Zhang, Yameng Li, Ziyu Liang

《环境科学与工程前沿（英文）》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1273-6

摘要： Abstract • Simply doping sands with ZVI achieved an even activation of ZVI by oxidants. • Sand doping facilitated proportional As trapping along the ZVI/oxidants column. • ZVI/sand/oxidants are highly efficient for arsenic removal. • ZVI/sand/oxidants reduced significantly the Fe2+ leaching and effluent turbidity. • More than 54% of arsenic was reduced to As(III) in ZVI/sand/oxidants system. The coupling of zero-valent iron (ZVI) with common oxidants has recently achieved very rapid and highly efficient removal of Heavy metals from wastewater. However, the uniform activation of ZVI throughout the column and the proportional removal of target contaminants are urgently required for the prevention of premature filter clogging and the extension of the effective column operational time. In this study, we successfully achieved this objective by simply doping granular sand with ZVI at appropriate weight ratios. When pure ZVI packed column was spiked with oxidants, the majority of As trapping occurred between the column inlet and the first sampling point. In a packed column with a 1:20 mixture of ZVI and sand, the average As removal efficiency was 36 (1st), 13.1 (2nd), 18.5 (3rd), 19.2 (4th) and 5.9% (5th outlet). The overall arsenic removal performance of the composite filling system of ZVI/sand was equally as efficient as that of the previous pure ZVI-packed system. Moreover, the leaching of Fe was significantly reduced with an increased sand ratio, resulting in clearer water with less turbidity. The results of X-ray photoelectron spectroscopy (XPS) demonstrated that more than 54% of the arsenic was reduced to As(III). X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the extensive corrosion of the ZVI surface, which resulted in various species of iron oxyhydroxides responsible for the highly efficient sequester of arsenic through reduction, adsorption, and coprecipitation.

关键词： Arsenic     ZVI     Sand     Oxidants     Fixed-bed Column     Removal    

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Impregnation of thermoplastic resin in jute fiber mat

LIU Xiaoye, DAI Gance

《化学科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 145-149 doi: 10.1007/s11705-008-0030-3

摘要： Impregnation rate of thermoplastic resin (polypropylene) in jute fiber mat and influence of relative factors on impregnation were studied, aiming to develop the continuous melt impregnation technique and to investigate the effect of impregnation rate and temperature on processing conditions and mechanical properties of natural fiber mat-reinforced thermoplastics. Influence of pressure on porosity of fiber mat and effect of melt viscosity on impregnation rate were also investigated. The modified capillary rheometer was used as apparatus and experimental data were analyzed based on the one-dimension Darcy’s law. Results showed that at a given pressure, the impregnation rate is inversely proportional to melt viscosity and jute fiber mat has higher porosity than glass fiber mat. The architecture, compressibility, permeability and fiber diameter of jute fiber mat were compared with those of glass fiber mat and their effects on impregnation were discussed further. It could be seen that the average diameter of jute fiber is much bigger; the porosity of jute fiber mat is significantly higher and inner bundle impregnation does not exist in jute fiber mat. Therefore, it is not difficult to understand why the impregnation rate in jute fiber mat is 3.5 times higher and permeability is 14 times greater. Kozeny constants of jute and glass fiber mats calculated based on the capillary model are 2950 and 442, respectively.

关键词： polypropylene     diameter     influence     proportional     impregnation    

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Porosity model for flows in CMP

ZHANG Chao-hui, YE Wei, LUO Jian-bin, WEN Shi-zhu

《机械工程前沿（英文）》 2006年 第1卷 第4期   页码 418-423 doi: 10.1007/s11465-006-0050-y

摘要： In an effort to explore the contribution of the pad, which is usually full of pores, to the performance of CMP (chemical mechanical polishing), a three-dimensional flow model of CMP is presented by assuming that the fluids in the porous layer comply with Darcy s law, which states that the flow velocity is proportional to the pressure gradient and inverse proportional to the viscosity. The flow equation is deduced accordingly and, by taking advantage of the multilevel technique and line relaxation technique, numerical simulations are carried out to reveal the relationships between the load capacities and operational parameters (including pivot height, roll angle and pitch angle), under conditions with different porous parameters and different thicknesses of the porous layer. The little porous parameter will lead to a prominent increase of load capability (for instance, the load and the moment predicted), which is still augmented by the thicker layer parameter. This will result in a higher material removal ratio of CMP. A pad full of large pores will be used to deduce load capability, facilitating the free flow of the fluids through the pores. The research will add some insights on the mechanism of the CMP technique.

关键词： multilevel technique     three-dimensional     proportional     research     thicker    

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Application of an efficient stochastic calculation method on the seismic analysis of an isolated structure

Wei GUO, Zhiwu YU

《结构与土木工程前沿（英文）》 2012年 第6卷 第4期   页码 379-384 doi: 10.1007/s11709-012-0180-8

摘要： An isolated structure often possesses distinct non-proportional damping characteristics. However, traditional seismic calculation theory and methods are derived based on the assumption that damping is proportional. Based on this drawback, a new, more efficient stochastic calculation method, an improvement on the pseudo-excitation method, is introduced. This method is then applied to the seismic analysis of an isolated structure. By comparing it with the forced decoupling, matrix inversion and iteration methods, it is shown that the presented method can produce accurate results while increasing the efficiency of the stochastic analysis. Moreover, the calculation process of the seismic response of an isolated structure is convergent. Based on the results of the example presented in this paper, the given method is applicable to the seismic analysis of an isolated structure and can be utilized in practice.

关键词： isolated structure     stochastic response     non-proportional damping     efficient     accurate     pseudo-excitation method    

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Control algorithm of a servo platform

Shouyong XIE, Xiwen LI, Shuzi YANG, Mingjin YANG,

《机械工程前沿（英文）》 2010年 第5卷 第3期   页码 353-355 doi: 10.1007/s11465-010-0098-6

摘要： According to the characteristics of the movement of a special-purpose three-axis servo platform, this paper presents an improved grey prediction proportional integral derivative (PID) control algorithm. Different weights at different time are given to different sampling moments in the algorithm, and the time meanings of the sample data are paid more attention. Simulation results show that the performance of response and stability of the platform of the improved algorithm is better than that of the traditional one. The control algorithm meets all requirements of the control system of the special-purpose three-axis servo platform.

关键词： grey prediction     proportional integral derivative (PID) control     improved algorithm     weight     servo platform    

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Elliptical lobe shape gerotor pump design to minimize wear

Mohammad Reza KARAMOOZ RAVARI

《机械工程前沿（英文）》 2011年 第6卷 第4期   页码 429-434 doi: 10.1007/s11465-011-0247-6

摘要：

The gerotor pumps are the most important parts of mechanical equipment that have a vast number of applications in industries and automobiles. Because the gerotor pumps cannot be adjusted for wear so it is important to reduce the wear as much as possible. In this paper first mathematical equations for elliptical lobe shape rotors profile and curvature of them have been derived and then Specific flow and wear rate proportional factor (WRPF) have been formulated. To reach the minimum wear in rotors teeth, the ellipse shape factor is changed for each value of number of outer rotor teeth in a feasible range and wear rate proportional factor has been resulted. Also in order to have better comparison specific flow has been presented. The obtained results have been compared with circular pumps with similar geometrical parameters and show the significant improvement in wear of the rotors with negligible changes in the specific flow.

关键词： gerotor pump     elliptical lobe shape pump     wear rate proportional factor (WRPF)     specific flow    

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Convergence performance comparisons of PID, MRAC, and PID+MRAC hybrid controller

Dan ZHANG,Bin WEI

《机械工程前沿（英文）》 2016年 第11卷 第2期   页码 213-217 doi: 10.1007/s11465-016-0386-x

摘要：

This study proposes a hybrid controller by combining a proportional-integral-derivative (PID) control and a model reference adaptive control (MRAC), which named as PID+MRAC controller. The convergence performances of the PID control, MRAC, and hybrid PID+MRAC are also compared. Through the simulation in Matlab, the results show that the convergence speed and performance of the MRAC and the PID+MRAC controller are better than those of the PID controller. In addition, the convergence performance of the hybrid control is better than that of the MRAC control.

关键词： proportional-integral-derivative (PID) control     model reference adaptive control     hybrid control     convergence speed     comparison    

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Stability and coupling dynamic behavior of nonlinear journal active electromagnetic bearing rotor system

LU Yanjun, HEI Di, WANG Yuan, DAI Rong, LU Yanjun, LIU Heng, YU Lie

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 193-199 doi: 10.1007/s11465-008-0023-4

摘要： The stability and coupling dynamic behavior of a journal active electromagnetic bearing rotor system are analyzed. The gyroscopic effect is considered in the rotor model. The system equations are formulated by combining equations for rotor motion and decentralized proportional integral differential (PID) controllers. A method combining the predictor-corrector mechanism and the Netwon-Raphson method is presented to calculate the critical speed at the corresponding Hopf bifurcation point of the system. For periodic motions, a continuation method combining the predictor-corrector mechanism and shooting method is presented. Nonlinear unbalanced periodic motions and their stability margins are obtained using the shooting method and established continuation method for periodic motions. With the change of control parameters, the system local stability and bifurcation behaviors are obtained using the Floquet theory. The numerical examples show that the schemes not only significantly save computing cost, but also have high precision.

关键词： proportional integral     bifurcation     corresponding     integral differential     predictor-corrector mechanism    

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High-precision gyro-stabilized control of a gear-driven platform with a floating gear tension device

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 487-503 doi: 10.1007/s11465-021-0635-5

摘要： This study presents an improved compound control algorithm that substantially enhances the anti-disturbance performance of a gear-drive gyro-stabilized platform with a floating gear tension device. The tension device can provide a self-adjustable preload to eliminate the gap in the meshing process. However, the weaker gear support stiffness and more complex meshing friction are also induced by the tension device, which deteriorates the control accuracy and the ability to keep the aim point of the optical sensors isolated from the platform motion. The modeling and compensation of the induced complex nonlinearities are technically challenging, especially when base motion exists. The aim of this research is to cope with the unmeasured disturbances as well as the uncertainties caused by the base lateral motion. First, the structural properties of the gear transmission and the friction-generating mechanism are analyzed, which classify the disturbances into two categories: Time-invariant and time-varying parts. Then, a proportional-integral controller is designed to eliminate the steady-state error caused by the time-invariant disturbance. A proportional multiple-integral-based state augmented Kalman filter is proposed to estimate and compensate for the time-varying disturbance that can be approximated as a polynomial function. The effectiveness of the proposed compound algorithm is demonstrated by comparative experiments on a gear-drive pointing system with a floating gear tension device, which shows a maximum 76% improvement in stabilization precision.

关键词： inertially stabilized platform     floating gear tension device     nonlinear friction     disturbance compensation     proportional multiple-integral observer    

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THD reduction with reactive power compensation for fuzzy logic DVR based solar PV grid connected system

Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR

《能源前沿（英文）》 2014年 第8卷 第4期   页码 464-479 doi: 10.1007/s11708-014-0307-9

摘要： Dynamic voltage restorer (DVR) is used to protect sensitive loads from voltage disturbances of the distribution generation (DG) system. In this paper, a new control approach for the 200 kW solar photovoltaic grid connected system with perturb and observe maximum power point tracking (MPPT) technique is implemented. Power quality improvement with comparison is conducted during fault with proportional integral (PI) and artificial intelligence-based fuzzy logic controlled DVR. MPPT tracks the actual variable DC link voltage while deriving the maximum power from a photovoltaic array and maintains DC link voltage constant by changing modulation index of the converter. Simulation results during fault show that the fuzzy logic based DVR scheme demonstrates simultaneous exchange of active and reactive power with less total harmonic distortion (THD) present in voltage source converter (VSC) current and grid current with fast tracking of optimum operating point at unity power factor. Standards (IEEE-519/1547), stipulates that the current with THD greater than 5% cannot be injected into the grid by any distributed generation source. Simulation results and validations of MPPT technique and operation of fuzzy logic controlled DVR demonstrate the effectiveness of the proposed control schemes.

关键词： fuzzy logic     maximum power point tracking (MPPT)     proportional integral (PI)     control     voltage restorer    

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Power quality investigation of a solar PV transformer-less grid- connected system fed DVR

Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR

《能源前沿（英文）》 2014年 第8卷 第2期   页码 240-253 doi: 10.1007/s11708-014-0322-x

摘要： This paper presents a single stage transformer-less grid-connected solar photovoltaic (PV) system with an active and reactive power control. In the absence of active input power, the grid-tied voltage source converter (VSC) is operated in a reactive power generation mode, which powers the control circuitry, and maintains a regulated DC voltage to the VSC. A data-based maximum power point tracking (MPPT) control scheme which performs power quality control at a maximum power by reducing the total harmonic distortion (THD) in grid injected current as per IEEE-519/1547 standards is implemented. A proportional-integral (PI) controller based dynamic voltage restorer (DVR) control scheme is implemented which controls the grid side converter during single-phase to ground fault. The analysis includes the grid current THD along with the corresponding variation of the active and reactive power during the fault condition. The MPPT tracks the actual variable DC link voltage while deriving the maximum power from the solar PV array, and maintains the DC link voltage constant by changing the modulation index of the VSC. Simulation results using Matlab/Simulink are presented to demonstrate the feasibility and validations of the proposed novel MPPT and DVR control systems under different environmental conditions.

关键词： data-based maximum power point tracking (MPPT)     total harmonic distortion (THD)     proportional integral     control     voltage restorer     pulse width modulation    

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Modeling and control of a permanent magnet synchronous generator dedicated to standalone wind energy conversion system

Louar FATEH,Ouari AHMED,Omeiri AMAR,Djellad ABDELHAK,Bouras LAKHDAR

《能源前沿（英文）》 2016年 第10卷 第2期   页码 155-163 doi: 10.1007/s11708-016-0410-1

摘要： The interest for the use of renewable energies has increased, because of the increasing concerns of the environmental problems. Among renewable energies, wind energy is now widely used. Wind turbines based on an asynchronous generator with a wound rotor present the inconvenience of requiring a system of rings and brooms and a multiplier, inferring significant costs of maintenance. To limit these inconveniences, certain manufacturers developed wind turbines based on synchronous machines with large number of pairs of poles coupled directly with the turbine, avoiding using the multiplier. If the generator is equipped with permanent magnets, the system of rings and brooms is eliminated. The control of the permanent magnet synchronous generator (PMSG) can be affected with the implementation of various techniques of control. This paper presented a new approach mainly based on the control strategy of power production system based on the PMSG. In fact, a mathematical model that simulates the Matlab chain was established with the introduction of control techniques, such as direct control of the torque (DTC) to control the load side converter (LSC), the control of the speed of the turbine and the DC-bus voltage ensured by PI regulators. To show the performance of the correctors used, some simulation results of the system were presented and analyzed.

关键词： wind turbine     permanent magnet synchronous generator (PMSG)     converter     proportional-integral (PI)     control     direct control of the torque (DTC)     regulation    

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Multiple target implementation for a doubly fed induction generator based on direct power control under unbalanced and distorted grid voltage

Heng NIAN,Yi-peng SONG

《信息与电子工程前沿（英文）》 2015年 第16卷 第4期   页码 321-334 doi: 10.1631/FITEE.1400170

摘要： This paper presents a multiple target implementation technique for a doubly fed induction generator (DFIG) under unbalanced and distorted grid voltage based on direct power control (DPC). Based on the mathematical model of DFIG under unbalanced and distorted voltage, the proportional and integral (PI) regulator is adopted to regulate the DFIG average active and reactive powers, while the vector PI (VPI) resonant regulator is used to achieve three alternative control targets: (1) balanced and sinusoidal stator current; (2) smooth instantaneous stator active and reactive powers; (3) smooth electromagnetic torque and instantaneous stator reactive power. The major advantage of the proposed control strategy over the conventional method is that neither negative and harmonic sequence decomposition of grid voltage nor complicated control reference calculation is required. The insensitivity of the proposed control strategy to DFIG parameter deviation is analyzed. Finally, the DFIG experimental system is developed to validate the availability of the proposed DPC strategy under unbalanced and distorted grid voltage.

关键词： Direct power control     Doubly fed induction generator     Unbalanced and distorted grid voltage     Vector proportional and integral resonant regulator     Parameter deviation    

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标题 作者 时间 类型 操作

Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

期刊论文

Proportional directional valve based automatic steering system for tractors Project supported

Jin-yi LIU,Jing-quan TAN,En-rong MAO,Zheng-he SONG,Zhong-xiang ZHU

期刊论文

The coupling of sand with ZVI/oxidants achieved proportional and highly efficient removal of arsenic

Sana Ullah, Xuejun Guo, Xiaoyan Luo, Xiangyuan Zhang, Yameng Li, Ziyu Liang

期刊论文

Impregnation of thermoplastic resin in jute fiber mat

LIU Xiaoye, DAI Gance

期刊论文

Porosity model for flows in CMP

ZHANG Chao-hui, YE Wei, LUO Jian-bin, WEN Shi-zhu

期刊论文

Application of an efficient stochastic calculation method on the seismic analysis of an isolated structure

Wei GUO, Zhiwu YU

期刊论文

Control algorithm of a servo platform

Shouyong XIE, Xiwen LI, Shuzi YANG, Mingjin YANG,

期刊论文

Elliptical lobe shape gerotor pump design to minimize wear

Mohammad Reza KARAMOOZ RAVARI

期刊论文

Convergence performance comparisons of PID, MRAC, and PID+MRAC hybrid controller

Dan ZHANG,Bin WEI

期刊论文

Stability and coupling dynamic behavior of nonlinear journal active electromagnetic bearing rotor system

LU Yanjun, HEI Di, WANG Yuan, DAI Rong, LU Yanjun, LIU Heng, YU Lie

期刊论文

High-precision gyro-stabilized control of a gear-driven platform with a floating gear tension device

期刊论文

THD reduction with reactive power compensation for fuzzy logic DVR based solar PV grid connected system

Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR

期刊论文

Power quality investigation of a solar PV transformer-less grid- connected system fed DVR

Akhil GUPTA,Saurabh CHANANA,Tilak THAKUR

期刊论文

Modeling and control of a permanent magnet synchronous generator dedicated to standalone wind energy conversion system

Louar FATEH,Ouari AHMED,Omeiri AMAR,Djellad ABDELHAK,Bouras LAKHDAR

期刊论文

Multiple target implementation for a doubly fed induction generator based on direct power control under unbalanced and distorted grid voltage

Heng NIAN,Yi-peng SONG

期刊论文