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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

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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...

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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

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Reconstruction of interfacial configuration in stratified two-phase flow using ECT 7

Reconstruction of interfacial configuration in stratified tw...

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7th World Congress in Industrial process Tomography, WCIPT7

作者： Ren, S. 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

Stratified two-phase flow is normal seen in many industrial applications. Measurement of the phase interfaces in it is important for the optimization of many industrial processes. In the paper, a shape reconstruction method is proposed for the direct reconstruction of phase interfaces in stratified two-phase flow using electrical capacitance tomography (ECT). The proposed method is mainly based on the Bézier presentation of the phase interface and the cornice boundary integral formulization of the forward problem of ECT. Numerical simulations show that the proposed method can reconstruct the interfacial configuration in stratified flow with good accuracy and high convergence. © 2014 International Society for Industrial process Tomography.

关键词： Boundary element method

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Research on Flow Diagnosis of Multipath Ultrasonic Flowmeter

Research on Flow Diagnosis of Multipath Ultrasonic Flowmeter

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IEEE International Instrumentation and Measurement Technology Conference

作者： Dan-Dan Zheng Jing-Li Zhang Shan-Shan Zhao Hua-Xiang Wang Zi-Qiang Cui Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin China

ISBN: (纸本)9781479961153

In the application of ultrasonic flowmeter, flow measurement has a low accuracy, since the length of straight pipe near the ultrasonic sensor is insufficient, especially the presence of the upstream disturbance. In this paper, in order to analyze the inherent relationship between the measurement error and the characteristics of flow field, two flow diagnostic criterions are proposed: asymmetry index (AR1, AR2) and cross flow (cf) indicator. Then the threshold range of the indexes is predicted by computational fluid dynamics numerical simulation in three non-ideal installations (single elbow, single elbow & rectifier, single elbow & 5 pipe diameter & rectifier). Finally, this diagnostic criterion is put forward to distinguish the three operating conditions, and verified by flow experiments. When AR1>0.019 or AR2 > 0.037 and cf > 0.005, the asymmetry and cross flow in the flow field cannot be ignored. At this time, flow measurement accuracy is greater than 1%. It is indicated that disturbance affect measurement accuracy. On the contrary, when diagnostic indexes are less than the threshold values, measurement accuracy can be guaranteed within 1%, which shows that disturbance have little impact on flow measurement.

关键词： Ultrasonic flowmeter Non-idealflowfield Asymmetric flow Cross flow

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ERT application software for multiphase flow measurement 6

ERT application software for multiphase flow measurement

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6th World Congress in Industrial process Tomography

作者： Ren, Shangjie Tan, Chao 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

Multiphase flow is commonly encountered and of paramount significance in both natural and industrial processes. Accurate measurement on its process parameters is difficult to achieve due to its rheological complexity. It has become an urgent issue to scientific researchers and industrial engineers. ERT is a promising technology to measure the multiphase flow due to its capability of producing two/three dimensional realtime information related to interior behaviours of medium within the closed process equipments, such as close pipes, vessels and so on. In this paper, an ERT application software for the measurement of multiphase flow is presented. It works with a high speed data acquisition system, which is based on CompactPCI and a 16channel parallel digital data acquisition strategy. To improve the speed and accuracy of online measurement, some techniques have been implemented in this software, such as modularized software structure, multithreading technology, multiprocessing technology, and Open Graphics Library. Additional, a DMA data transmission strategy based on CompactPCI communication protocol is developed and implemented in this software. It makes this system more conform to the industrystandard and the data transmission speed been improved greatly. This software is capable of acquiring 1400 frames data per second and reconstructing crosssection images at a rate of 60 frames per second on a Windows based PC with a 1.8GHz Pentium Dual CPU, while saving measurement results and extracting flow parameters synchronously. © 2010, International Society for Industrial process Tomography. All rights reserved.

关键词： Multiphase flow

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Robust Fault Detection for Nonlinear Time-delay Systems Based on Fuzzy Observer 33

Robust Fault Detection for Nonlinear Time-delay Systems Base...

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第三十三届中国控制会议

作者： TAO Hongfeng ZHANG Hua HU Shousong Key Laboratory of Advanced Process Control for Light Industry Ministry of Education Jiangnan University College of Automation Engineering Nanjing University of Aeronautics and Astronautics

ISBN: (纸本)9781479947249

Robust fault detection method based on fuzzy sliding mode observers is developed for a class of uncertain nonlinear systems with time-delay. The uncertain Takagi-Sugeno fuzzy model with time-delay is adopted for fuzzy modeling of nonlinear system to reduce the modeling error, and a synthesis method of the design of sliding mode observers is introduced to generate the estimate state error and residual then to eliminate the effect of the unknown uncertainties of the system for avoiding false alarms, the synthesis method of the observers is presented via solving LMIs. Finally, a simulation example is given to show the design procedure and illustrate the effectiveness of the proposed method.

关键词： nonlinear time-delay systems,sliding mode observer,T-S fuzzy model,fault detection

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Nonlinear asymptotic attitude tracking control for an unmanned helicopter with input constraints

Nonlinear asymptotic attitude tracking control for an unmann...

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2014 American control Conference, ACC 2014

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

ISBN: (纸本)9781479932726

In this paper a nonlinear attitude tracking control scheme is developed for a small-scaled unmanned helicopter under input constraints. Via the analysis of the properties associated with the helicopter's rotor dynamics, the elevator servo input, the aileron servo input, and the rudder servo input are chosen to be the control inputs to be designed. Their constraints in amplitude under hovering flight is taken into account by using the robust bounded terms in the controller design. The asymptotic convergence of the tracking error is guaranteed with the Lyapunov-based stability analysis. © 2014 American Automatic control Council.

关键词： Navigation

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Ultrasound Attenuation Characteristics in Oil-water Two-phase Flow

Ultrasound Attenuation Characteristics in Oil-water Two-phas...

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IEEE International Instrumentation and Measurement Technology Conference

作者： Qian Su Chao Tan Feng Dong Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China

ISBN: (纸本)9781479961153

Accurate measurement of multiphase flow parameter has significance on the optimization of production process and equipment. Ultrasonic measurement technology has potential applications in two-phase flow measurement. In order to understand the ultrasonic testing mechanism, the ultrasound attenuation characteristics in the oil-water two-phase flow are numerically investigated. Two-dimension models of ultrasonic sensor are set up based on the finite element analysis method. Through calculation of ultrasound pressure distribution in oil-water two-phase flow, the effects of different oil fractions on ultrasound attenuation in oil droplet structure and stratified structure are simulated. Simulation results show that phase distribution and fraction have direct influence on the ultrasound attenuation.

关键词： two-phase flow phase fraction testing mechanism ultrasound attenuation finite element method

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A sequential linear programming matrix method to insensitive h ∞ output feedback for linear discrete-time systems

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Journal of Dynamic Systems, Measurement and control, Transactions of the ASME 2014年第1期136卷 014506页

作者： Guo, Xiang-Gui Yang, Guang-Hong Tianjin Key Laboratory for Control Theory and Applications in Complicated System School of Electrical Engineering Tianjin University of Technology Tianjin 300384 China State Key Laboratory of Synthetical Automation for Process Industries College of Information Science and Engineering Northeastern University Shenyang 110819 China

This paper studies the problem of designing insensitive H∞ output-feedback controllers for linear discrete-time systems. The designed controllers are insensitive to additive/multiplicative controller coefficient variations. An LMI-based procedure, which is a sequential linear programming matrix method (SLPMM), is proposed to solve the considered problem which is a nonconvex problem itself. It is worth mentioning that the nonfragile control design method is adopted to obtain an effective solution for accelerating convergence of SLPMM algorithm due to the fact that a good starting point for the iteration is very important. © 2013 by ASME.

关键词： controllers

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Double-Objective Optimal control for Non-Gaussian Systems: An Example Study on Analytical vs Numerical Solutions

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IFAC-PapersOnLine 2015年第8期48卷 924-929页

作者： Mifeng Ren Jianhua Zhang Hong Wang Min Huang College of Information Engineering Taiyuan University of Technology Taiyuan 030024 China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China Control System Centre School of Electrical and Electronics Engineering The University of Manchester M60 1QD UK China State Key Laboratory of Synthetical Automation for Process Industry Northeastern University Shenyang 110819 China

Minimum entropy control has been proven to be an effective method in control of non-Gaussian stochastic systems. In this case, the entropy is proposed as a generalization of the variance measure to characterize the randomness of the process. Minimum entropy corresponds to small uncertainty (or derivation), but it cannot guarantee the tracking error approaching to zero. Therefore, mean square error also should be added in the criterion. In this paper, by using a simple example, the method of generating a representative approximation of the Pareto optimal control set is investigated in both analytical and numerical ways. And simulation results show the feasibility of the proposed double-objective optimal control method.

关键词： Double-objective optimal control non-Gaussian stochastic systems Renyi's entropy e - constrained method estimation of distribution algorithm

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