检索结果-内蒙古大学图书馆

Force control of Electro-Hydraulic Servo System Based on Load Velocity Compensation

Journal of Beijing Institute of Technology 2018年第3期27卷 326-333页

作者： Shoukun Wang Hu Liu Junzheng Wang Deyang Zhang Key Laboratory of Intelligent Control and Decision of Complex Systems School of AutomationBeijing Institute of Technology

In an electro-hydraulic servo control system,the force servo system is an important ***,due to the nonlinear characteristic of hydraulic systems,traditional control methods cannot achieve satisfactory control *** deal with this issue,a load velocity compensation algorithm based on the structural invariant principle is proposed in this ***,the theoretical analysis of the hydraulic and cylindrical force control system is presented,and the mathematical model of the force control system is *** the open-loop frequency response characteristics of the system are analyzed,in which the Bode diagram shows that the bandwidth of the system is obviously expanded after adopting the load velocity compensation ***,apractical hydraulic and cylindrical force servo system is introduced to validate the feasibility of the proposed controller,the experimental results demonstrate that the proposed method can improve the performance of force control and eliminate the influence of load stiffness on the dynamic characteristics of the system through a set of comparative experiments with different elastic loads.

关键词： electro-hydraulic servo control system force servo control load velocity compensation elastic load

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Simplified Method for Joint Calibration of 3D Ladar and Monocular Camera

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Journal of Beijing Institute of Technology 2018年第3期27卷 319-325页

作者： Jing Li Liuzhi Yu Junzheng Wang Key Laboratory of Intelligent Control and Decision of Complex Systems School of AutomationBeijing Institute of Technology

To address the problem of data fusion between monocular camera image with 3 D data from laser detection and ranging(LADAR)sensor,this paper proposes a novel simplified scheme based on the planar feature method,which can meet the accuracy requirements of the joint calibration with fewer checkerboard calibration plate(CP)positions than traditional ***,a mathematical model of the joint calibration is established to obtain the calibration ***,the selection of positions and orientations of the CP are introduced and the corresponding influence to the calibration is ***,the calibration result is optimized by using a nonlinear Levenberg-Marquardt(LM)optimization approach,and the distance residual method is utilized to estimate the ***,experimental results conclude that the minimum number of positions required to meet the joint calibration accuracy in the proposed method is 5,which is less than 12 in traditional methods.

关键词： 3D LADAR monocular camera joint calibration plane calibration method distance residual

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Shaping Effect of Phase-locked Loop on Impedance Characteristics of PMSG Wind Turbines Connected to Weak-grid

Shaping Effect of Phase-locked Loop on Impedance Characteris...

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IEEE General Meeting Power& Energy Society

作者： Feiya Wan Zhen Li Bin Liu Guanghui Li Xiaoliang Dong Xi Chen Samson S. Yu Amanullah M. T. Oo Zhenyu Shan Xiangdong Liu School of Automation and Key Laboratory for Intelligent Control & Decision on Complex Systems Beijing Institute of Technology Beijing China China Electric Power Research Institute Beijing China State Grid Corporation of China and North China Branch of State Grid Corporation of China Beijing China GEIRI North America USA School of Engineering Deakin University 75 Pigdon Rd Waurn Ponds Victoria Australia School of Electrical and Control Engineering North China University of Technology Beijing China

ISBN: (数字)9781728155081

ISBN: (纸本)9781728155098

With the booming installed capacity of permanent magnet synchronous generator (PMSG) for wind energy generation, the grid becomes weaker and the oscillation events are frequently observed in weak-grid-tied large-scale grid-connected PMSG wind farms. Although the impedance-based method is effective to analyze the stability of grid-connected systems, the mathematical relationship between external impedance characteristics and the internal controllers has not been quantitatively analyzed in depth, which is beneficial to the controller design. This paper studies the influence of phase-locked loop (PLL) on the impedance characteristics based on the analytical sequence impedance model of PMSG with typical topology and control structure. The shaping effect of PLL on the impedance characteristics is described so as to clearly describe the relationship between the external impedance characteristics of the wind turbines and the internal controller. Finally, the stability analysis of the grid-connected PMSG wind turbine system is provided in Matlab and simulation results are given to verify the oscillating mechanism caused by PLL.

关键词： Synchronous generators Stability analysis Wind turbines Topology Impedance Phase locked loops Oscillators

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Design of the Cement-Hydration-Characteristics Measuring Device

Design of the Cement-Hydration-Characteristics Measuring Dev...

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Chinese control Conference (CCC)

作者： Wangyong He Juanjuan Wang Yuanjiang Wang Zhenzhu Liu Zhenjiang Feng Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan P.R. China

In order to study the cement hydration characteristics in the process of cement condensation, based on eddy current measuring technology and GMR (giant magnetoresistive sensor), it designed a non-contact cement-hydration-characteristics measuring device. As an advanced nondestructive detection technology, Eddy current detection is convenient and non-contact. And GMR has high sensitivity and good linearity. Combining eddy current detection technology with GMR in design, it successfully gets rid of electrode polarization in traditional contact testing method, and greatly improves the accuracy of cement impedance measurement, and it effectively solves the collision problem that the excitation coil needs high frequency and the measure must have high sensitivity. The measuring device mainly includes magnetic field, GMR sensor, and STM32F427 micro-computer data acquisition system. The testing results show that the device has high precision, good repeatability.

关键词： Magnetic fields Eddy currents Current measurement Instruments Frequency measurement Sensitivity Software measurement

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Stable control of Single-Link Flexible-Joint Manipulator

Stable Control of Single-Link Flexible-Joint Manipulator

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Chinese control Conference (CCC)

作者： Ze Yan Xuzhi Lai Qingxin Meng Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan Hubei P. R. China

This paper presents a novel approach for stable control of a single-link flexible-joint manipulator (SLFJM). The control objective is to stabilize the SLFJM at the straight-up equilibrium position from the straight-down equilibrium position and suppress vibration by only using position measurement. First, differential homeomorphic transformation is used to equivalently convert the original system into a new handy system. Next, the new system is divided into two parts: linear and nonlinear. The nonlinear part is considered as a virtual disturbance of the linear part. Then, the Equivalent-input-disturbance-based (EID-based) control system is designed to suppress this virtual nonlinear disturbance at the zero equilibrium point. By this way, the control objective of the original system is effectively realized. Finally, the numerical results demonstrate its validity.

关键词： Manipulators Observers Vibrations Shafts State feedback

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A Detection System of Tool Parameter Using Machine Vision

A Detection System of Tool Parameter Using Machine Vision

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Chinese control Conference

作者： Hantao Wang Hong Wang Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems China University of Geosciences Wuhan China

This paper suggests a novel technique for the tool parameter measurement based on machine vision. Tool images are captured by using a machine vision system and the outer contour image of the cutter is obtained by using the machine vision technology. The HALCON image processing library is used as the development platform to build the tool parameters test system. Several algorithms including image segmentation, edge extraction and fitting ellipse determination is used for image processing. The tool parameters such as external diameter and contour angle of tool edge can be obtained after rebuilding the contour of tool edge. The proposed scheme is shown to be reliable and effective for the automated tool parameter measurement.

关键词： Tools Image edge detection Machine vision Monitoring Corrosion Milling

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GMI Effect Automatic Test System Based on Network Analyzer

GMI Effect Automatic Test System Based on Network Analyzer

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Chinese control Conference

作者： Zhi Zhao Hengchang Rao Fang Jin Jinchao Wang Lei Zhu Junlei Song Kaifeng Dong Wenqin Mo Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan P.R. China

The measuring instrument selects the network analyzer, combines the direct current source and the Helmholtz coil to form the GMI effect test system. PC program written in LabVIEW, network analyzer and DC current source is controlled by the host computer. The host computer can process and plot the impedance data collected by the network analyzer, and save the data and images locally. The test system by measuring the commercial Vitrovac6025 strip material, found that the material all showed a strong GMI effect at different frequencies. By comparing the measured data of the network analyzer and the impedance analyzer measured in the same frequency band, we found that the two are consistent, which verifies the accuracy and reliability of the test system.

关键词： Frequency measurement Impedance measurement Magnetic field measurement Impedance Magnetic fields Current measurement

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Load Frequency control in Power systems via A Sampled-Data controller

Load Frequency Control in Power Systems via A Sampled-Data C...

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第37届中国控制会议

作者： XingChen ShangGuan Yong He Lin Jiang School of Automation China University of Geosciences Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems University of Liverpool

In modern power systems, load frequency control(LFC) scheme usually operates in the discrete mode, while the most existing LFC schemes are designed in the continuous mode, such that those LFC schemes do not work usually in their best manner in practice. In this paper, a method of state-feedback controller design of load frequency control(LFC) for one–area system is discussed in continuous-discrete mode via sampled–data control scheme. At first, the model of LFC is constructed in continuous-discrete mode by using the input delay method. Then, a new method is present to design a state–feedback ***, a case study is given to show the effectiveness and the benefits of the proposed method.

关键词： Power system Load frequency control Sampled-data control State–feedback controller

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Bat Algorithm Optimizer for Drilling Trajectory Designing under Wellbore Stability Constraints

Bat Algorithm Optimizer for Drilling Trajectory Designing un...

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Chinese control Conference

作者： Jiafeng Xu Xin Chen Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems china University of Geosciences Wuhan China

In the process of deep geological resources exploration, there are often some complex stratigraphic situations. A three-dimension drilling trajectory is designed by using the geological environment data. The trajectory should be sure that the target position is reachable. And it can avoid the area prone to be in an accident. In order to solve this problem, this paper discusses a three-dimensional wellbore trajectory design optimization model suitable for shale gas horizontal mining. Considering the wellbore stability and dogleg severity as constraints, the minimum drilling length is taken as the objective function. Depending on the Mohr-Coulomb criterion, the range of azimuth angle and inclination angle of safety trajectory can be determined. It can be seen as a constraint on the wellbore derrick segment. As for the optimization algorithm, bat algorithm (BA) optimizer combined with a penalty function method is applied to this optimization model. Finally, the case study shows that the BA performs well in the wellbore optimization design. It obtains the trade-off result between the safe and efficient drilling demands. And. it provides a basic model idea for the real-time trajectory optimization while drilling.

关键词： Trajectory Stress Mathematical model Stability criteria Geology Azimuth

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Fast Automatic Localization of Epileptic Seizure Onset Zones Using complex Morlet Wavelet Transform-based Singular Value Decomposition

Fast Automatic Localization of Epileptic Seizure Onset Zones...

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Chinese control Conference

作者： Zelin Fang Xiongbo Wan Ting Wan Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan Hubei P. R. China

A new method for localization of epileptic seizure onset zones (SOZs) is proposed, which uses the Shannon-entropy-based complex Morlet wavelet transform to extract a satisfactory time-frequency feature of high-frequency oscillations (HFOs). The singular value decomposition and the K-medoids clustering algorithm are employed to extract effective features from the redundant matrix of wavelet coefficients. A distinctive feature is to use the singular values to detect HFOs with the consideration that the singular values of HFOs are generally significantly higher than those of normal case. Based on the half-maximum method, the localization of SOZs are achieved by using the characteristics of HFOs. Comparisons show that our method provides a higher sensitivity and specificity than two existing methods do.

关键词： Hafnium oxide Clustering algorithms Feature extraction Wavelet transforms Singular value decomposition Oscillators

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