检索结果-内蒙古大学图书馆

Measurement and analysis of liquid film velocity in annular flow based on laser-induced fluorescence

Guangdianzi Jiguang/Journal of Optoelectronics Laser 2015年第3期26卷 523-528页

作者： Xue, Ting Ge, Peng-Hui Yang, Liu-Xiang-Zi Tianjin Key Laboratory of Process Measurement and Control College of Electrical Engineering and Automation Tianjin University Tianjin China

The parameters measurement of liquid film in gas-liquid two-phase annular flow is of great significance for the study of heat and mass transfer and flow characteristics. Laser-induced fluorescence technique based on optical measurement principles to measure film parameters can be simply implemented with high accuracy and without interference of flow fields. Compared with the traditional measurement methods, the method combining the laser-induced fluorescence technique with the cross-correlation technique is developed to measure the liquid film velocity and analyze the flow characteristics. With the aid of digital image processing technology, curves of film thickness at different locations are figured out based on the film images shot by high-speed camera. The flow velocity of the liquid film is accurately measured by processing the images at a fixed interval frame based on the cross-correlation technique. The parabolic fitting technique can be used to estimate the largest correlation coefficient with a higher accuracy and improve the measurement accuracy of film velocity. The experimental results show that the non-intrusive measurement method with a wider range of application can effectively detect the liquid film "break-up" phenomenon and extract the liquid film flow velocity with a higher accuracy. ©, 2015, Board of Optronics Lasers. All right reserved.

关键词： Flow velocity

来源：评论

学校读者我要写书评

暂无评论

A Three-level Batching Strategy for the Planning of Steelmaking-continuous Casting Production

引用

IFAC-PapersOnLine 2015年第25期48卷 144-149页

作者： Liangliang Sun Fangjun Luan Tianmu Ma Department of Information and Control Engineering Shenyang Jianzhu University Shenyang Liaoning Province China 110004 (Tel: +86(24)23998315 Key Laboratory of Integrated Automation of Process Industry Ministry of Education Northeastern University Shenyang Liaoning Province China 110004 (Tel: +86(24)23998315

This paper focuses on the optimal planning of steelmaking-continuous casting production in real steelmaking plant. The tasks of steelmaking planning are to make the decisions as how to determine the relation between slabs and charges, the sequence of charges in casts and the casting width of slabs while considering the known information about the contract properties, the size properties and processing properties, etc. Effective planning can satisfy the capacity of downstream and continuously casting the steel molten. A three-level batching policy consisting of charge planning, tundish planning, cast planning is proposed in this paper. The different requirement of width in charge planning, tundish planning, cast planning are considered as the performance indicators and constraints equations respectively to formulate the problems. A hybrid optimal strategy combined with the iterated local search (ILS), variable neighborhood search (VNS), and the hybrid optimal strategy with ant colony optimization is adopted. Numerical experiments are done to verify the effectiveness of the three-level batching strategy by using practical data set collected from the steelmaking plant in Baosteel which is one of the most advanced iron and steel enterprises in China. Computational experiments demonstrate that the models and algorithms developed can make an optimal planning in a computationally efficient manner to improve the steel production.

关键词：

来源：评论

学校读者我要写书评

暂无评论

On control design and tuning for first order plus time delay plants with significant uncertainties

On control design and tuning for first order plus time delay...

引用

American control Conference

作者： Lijun Wang Qing Li Chaonan Tong Yixin Yin Zhiqiang Gao Qinling Zheng Weicun Zhang School of Automation & Electrical Engineering University of Science and Technology Beijing Beijing 100083 China Key Laboratory of Advanced Control of Iron and Steel Process Ministry of Education Beijing 100083 China Center for Advanced Control Technologies Cleveland State University Cleveland OH 44115 USA

ISBN: (纸本)9781479917730

A novel active disturbance rejection control (ADRC) solution and a particular tuning method are presented for a class of time delay system (TDS) with uncertainty. First, the complicated process dynamics is modeled as a simple first order plus large time delay (FOPTD) plant, with the difference between the actual dynamics and its model treated as disturbances to be rejected. Then the reduced order linear extended state observer (RLESO) with input delay is proposed to estimate the time delay state and disturbance. It is shown how the time delay could be eliminated from the characteristic equation of the closed-loop system by manipulations of controller parameters. Secondly, the one parameter tuning (OPT) technique is developed where all controller parameters are made function of a single coefficient. In comparison with optimal proportional-integral-derivative (PID) controller and twice optimum controller (TOC), the simulation results show that the proposed method not only has better accuracy and faster response, but also ensures better robustness and adaptability against uncertain model parameters and external disturbances, especially for the plant with very large time delays.

关键词： tuning design control model parameters process dynamics Characteristic equation one-parameter external disturbance FIRST ORDER controllers Closed loop systems

来源：评论

学校读者我要写书评

暂无评论

Hovering control of a Nano Quadrotor Unmanned Aerial Vehicle Using Optical Flow 33

Hovering Control of a Nano Quadrotor Unmanned Aerial Vehicle...

引用

第三十三届中国控制会议

作者： XIAN Bin LIU Yang ZHANG Xu CAO Meihui Wang Fu The Institute of Robotics and Autonomous System the Tianjin Key Laboratory of Process Measurement and ControlSchool of Electrical Engineering and AutomationTianjin University

ISBN: (纸本)9781479947249

In this paper, a PD controller which uses optical flow to obtain position and velocity feedback is proposed for the autonomous hovering flight control of a nano quadrotor unmanned aerial vehicle(UAV). The nano quadrotor UAV has a mass less than 100 g and is comparatively much smaller than the micro vehicles utilized in previous research. Due to the limited size and payload ability, a wireless camera is employed as the onboard visual device to obtain the position and translational velocity of the UAV. Experiment results are included to demonstrate the good control performance of the proposed design.

关键词： Nano Quadrotor UAV,Optical Flow,Autonomous control

来源：评论

学校读者我要写书评

暂无评论

Automatic calibration method of voxel size for cone-beam 3D-CT scanning system

引用

Chinese Physics C 2014年第4期38卷 69-74页

作者：杨民王晓龙刘义鹏孟凡勇李兴东刘文丽魏东波 School of Mechanical Engineering and Automation Beijing Univ.of Aeronautics and Astronautics Department of Control Science and Engineering Harbin Institute of Technology State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences National Institute of Metrology

For a cone-beam three-dimensional computed tomography （3D-CT） scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary stage along X-ray direction. In order to realize the automatic calibration of the voxel size, a new and easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least-square fitting. Through these interpolation values, a linear equation is obtained that reflects the relationship between the voxel size and the rotary stage translation distance from its nominal zero position. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system. When the rotary stage is moving along X-ray direction, the accurate value of the voxel size is dynamically exported. The experimental results prove that this method meets the requirements of the actual CT scanning system, and has virtues of easy implementation and high accuracy.

关键词： cone-beam CT voxel size least square fitting automatic calibration

来源：评论

学校读者我要写书评

暂无评论

Performance evaluation and structure optimization of an inner-outer electrical resistance tomography sensor

Performance evaluation and structure optimization of an inne...

引用

International Conference on Mechatronics and control, ICMC 2014

作者： Shangjie, Ren Chao, Tan Yanbin, Xu Feng, Dong Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin China

ISBN: (纸本)9781479925384

Electrical resistance tomography is a useful visualization technique to imaging the conductivity distribution inside a closed pipeline from the boundary measurements. Due to its advantages of high speed, low cost and high safety, the technique has been successfully applied in the measurement of many industrial processes. However, since the mathematical model is highly non-linear and ill-posed, the spatial resolution of ERT is low, especially in the center of the objective domain. To overcome the problem, an inner-outer ERT sensor structure was proposed. The structure is consisted by the internal and external electrodes, and can provided more independent measurements for high resolution image reconstruction. To test the performance of the inner-outer sensor structure, six inner-outer ERT sensors are designed, and the influences of the size, number and distribution of the internal electrodes are discussed. After several numerical tests, the inner-outer ERT sensor is proved having the ability of enhancing the spatial resolution of ERT, especially in the area near the internal electrodes. © 2014 IEEE.

关键词： Image reconstruction

来源：评论

学校读者我要写书评

暂无评论

Determination of state changes for distributed parameter systems based on quantitative POD angle analysis

引用

Sensors and Transducers 2014年第6期172卷 263-271页

作者： Guan, Hongwei Ye, Lingjian Song, Zhihuan Ma, Xiushui Zhi, Xiongfei Institute of Industrial Process Control Zhejiang University Hangzhou China Ningbo Institute of Technology Zhejiang University Ningbo China College of electrical engineering and automation Anhui University Hefei China

For distributed parameter systems, recognition of state change is crucial to process operation with a wide range of motivations, for example, sensitivity analysis of input condition, selection of operating point and abnormal situation diagnosis, etc. A key task therein is developing a criterion from which the extent of state change can quantitatively determinated. In this paper, a novel concept, namely the POD (proper orthogonal decomposition) angle is proposed to form such a criterion, which is developed from the POD technique. Based on this new concept, some of its theoretical properties are also described and proven along with the introduction of POD angle. As an illustrative example for the usage of POD angle, a cyclohexane process is studied where the POD angle is used to analyze the influence of feed temperature on the temperature distribution of whole system. It is demonstrated that when feed temperature is operated in the range of 100 to 120 °, the POD angle will experience a change of 17.8022°, corresponding to fluctuant amplitude of 82.0309 ° for the system temperature. Therefore, temperature distribution of system is sensitive to feed temperature in this situation. On the other hand, when feed temperature is operated in the range of 120 to 200 °, the POD angle changes only 1.1595° on average whilst the temperature distribution of whole system average varies only 5.0486 °, hence we conclude that the feed temperature imposes a minor impact on the temperature of the system as compared with the former case. © 2014 IFSA Publishing, S. L.

关键词： Temperature distribution

来源：评论

学校读者我要写书评

暂无评论

A parallel data acquisition system based on CPCI for ERT 6

A parallel data acquisition system based on CPCI for ERT

引用

6th World Congress in Industrial process Tomography

作者： Xu, Cong Zhang, Zhiqiang Han, Jun Dong, Feng Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin300072 China

ISBN: (纸本)9780853163220

Electrical resistance tomography (ERT) is to achieve visual detection through boundary sensors array to obtain the realtime distribution of the sensing field. As a nonradiant and unperturbed 2D/3D boundary technique, ERT has wide application prospect in petroleum and chemical industrial processes with conductive continuous phase flow. For obtaining accurate information reflecting the sensing field, many data acquisition systems have been developed for online measurement. To better satisfy industrial requirements, ERT is presently expected to be more flexible, applicable and easier to extend. For this purpose, a system based on industrial bus standard is designed as a 16channel parallel data acquisition system, where FPGA and Compact PCI are adopted as the core components. FPGA is configured with logic control and basic algorithm’s implementation (including digital FIR filter and digital demodulation). Compact PCI, with identical electrical function with PCI but enhanced mechanic structure and hotplugging feature, is employed for highspeed datatransmission. Dedicated software with a userfriendly interface has been developed to configure the signal generator and data *** static experiments using this system have been done, and the results show that the data acquisition system works properly with SNR above 54dB, and the data acquisition rate of this ERT system could reach almost 1400 frames per second without affecting the performance. © 2010, International Society for Industrial process Tomography. All rights reserved.

关键词： Field programmable gate arrays (FPGA)

来源：评论

学校读者我要写书评

暂无评论

Compressed sensing framework for electrical resistance tomography 7

Compressed sensing framework for electrical resistance tomog...

引用

7th World Congress in Industrial process Tomography, WCIPT7

作者： Zhao, J. Tan, C. Dong, F. Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin300072 China

ISBN: (纸本)9780853163237

Image reconstruction for electrical resistance tomography (ERT) is a nonlinear and ill-posed inverse problem. In order to improve the imaging quality, compressed sensing (CS) is applied to measured signal recovery and image reconstruction of ERT system in this paper. Firstly, CS is used to sample and recover the signal measured by ERT system. Secondly, a signal recovery algorithm of CS is used in the image reconstruction with the recovered signal. Simulation results show that CS can recover the voltage difference signal with a smaller sampling number, and the imaging results have less artifacts than other three imaging algorithms. © 2014 International Society for Industrial process Tomography.

关键词： Image reconstruction

来源：评论

学校读者我要写书评

暂无评论

A continuous robust control design for a class of non-affine nonlinear dynamics with non-varnishing disturbance

A continuous robust control design for a class of non-affine...

引用

2014 American control Conference, ACC 2014

作者： Zhang, Yao Xian, Bin Zhao, Bo Liu, Xiang Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University 300072 Tianjin China

ISBN: (纸本)9781479932726

In this paper, the problem for the control of a class of single-input-single-output (SISO) non-affine nonlinear system with non-varnishing disturbance is investigated. A continuous nonlinear feedback structure is utilized to tackle with the uncertain dynamics in the system. By taking the time derivative of the origin system, a transformed affine-like form is derived. The first order derivative of control input appears linearly in the augmented dynamics with unknown control direction. Nussbaum-type function is incorporated to estimate the unknown control direction. A revised Lyapunov based analysis is carried out to prove that under some moderate assumptions, the Semi-global Uniformly Ultimately Bounded (SGUUB) tracking result is achieved and all the closed loop signals are bounded. Numerical simulation results are presented to illustrate the performance of the proposed control law. © 2014 American Automatic control Council.

关键词： Robust control

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：