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19th International Flow Measurement Conference 2022, FLOMEKO 2022

作者： Sun, Cenwei Xu, Ying Yuan, Chao Li, Tao Ma, Huimin Zhang, Yumeng Ba, Xili Tianjin Key Laboratory of Process Measurement and Control School of Electrical and Information Engineering Tianjin University Tianjin China PetroChina Planning & Engineering Institute Beijing China

ISBN: (纸本)9781713871989

With the development of the gas-liquid two phase flow dynamics theory and the continuous improvement of two phase flowrate measurement requirements, the importance of slug flow research has become increasingly prominent. The wire mesh sensor (WMS), which consists of the perpendicular "cross-point" between the transmitting wires and receiving wires, forms a particular "hard field" measurement mode. This paper aims to investigate the measurement characteristics and accuracy of a 16×16-electrode conductivity WMS with a spatial resolution of 3.125mm for gas-liquid two phase slug flow by means of flow experiments. Experiments were performed in a 50 mm horizontal pipe with air and water as the working medium at atmospheric conditions, meanwhile, the time series data were collected by WMS. Comparing the cross sectional, a good correspondence can be found in the cross sectional direction between axial reconstructed images of fluid distribution and averaged void fraction time series. The WMS can realize the quantitative measurement of local void fraction and the qualitative spatial phase reconstruction of fluid distribution. Furthermore, distribution characteristics of the cross sectional averaged void fraction time series of gas-liquid two phase slug flow were analyzed. We found when superficial gas velocity is less than 3 m/s, the gas phase mainly exists in the form of elongate gas slug. When superficial gas velocity is around 5 m/s, it appears as typical bullet-shape gas slug. As superficial gas velocity increases to 10 m/s, the liquid slug becomes blurred and the gas phase almost penetrates through the liquid slug structures. In addition, a Probability Density Function (PDF) is generated from the instantaneous cross sectional averaged void fraction data for different flow regime conditions. The results show that the PDFs for lower superficial gas velocity case (3 m/s), two peaks in the void fraction signal are observed. Nevertheless, with an increase in superficial gas v

关键词： Void fraction

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A Void Fraction Measurement Method of Gas-water Flow Based on Microwave Method 19

A Void Fraction Measurement Method of Gas-water Flow Based o...

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19th International Flow Measurement Conference 2022, FLOMEKO 2022

作者： Ma, Huimin Xu, Ying Yuan, Chao Li, Tao Sun, Cenwei Zhang, Yumeng Wang, Nianrong Tianjin Key Laboratory of Process Measurement and Control School of Electrical and Information Engineering Tianjin University Tianjin China PetroChina Planning & Engineering Institute Beijing China

ISBN: (纸本)9781713871989

In the natural gas industry, measuring void fraction with high accuracy is challenging, because the flow pattern of gas-flow is complicated and changeable. This research presents a microwave sensor to measure void fraction of gas-water flow based on the microwave transmission line method. The sensor contains horizontal and vertical electrodes resulting in a spatial orthogonal transmission line combination structure, so that the gas-water flow regime can be detected and its influence on the measurement can be accounted for. The electromagnetic fields inside the sensor for stratified and annular distribution structure are simulated and analyzed using COMSOL software. Furthermore, the variation characteristics of the horizontal and vertical electrode phase outputs of the stratified distribution structure are investigated by static experiments. Finally, flow experiments covering stratified, wavy, slug, annular gas-water flow regimes, indicates that the void fraction are positive correlated to the sensor outputs and can be predict by the sensor. © FLOMEKO *** rights reserved

关键词： Void fraction

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Ultrasonic Transmission Tomography Image Reconstruction Using Total Variation Regularization with Spilt Bregman Method

Ultrasonic Transmission Tomography Image Reconstruction Usin...

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第43届中国控制会议

作者： Aoyu Li Guanghui Liang Feng Dong Tianjin Key Laboratory of Process Measurement and Control School of Electrical and Information EngineeringTianjin University School of Information and Intelligent Engineering Tianjin Renai College

ISBN: (数字)9789887581581

ISBN: (纸本)9798350366907

The total variation(TV) regularization method has good accuracy and edge preservation ability,and has been used to solve the inverse problem of ultrasonic transmission tomography(UTT).However,due to the need for multiple iterations of this method,the real-time performance of image reconstruction is often not *** improve the speed of image reconstruction without sacrificing the accuracy of image reconstruction,a Split Bregman(SB) iterative solution for TV regularization method is *** method is based on Bregman distance,which separates each variable in the constrained optimization equation independently and iteratively solves them *** method significantly reduces the number of iterations required for convergence and greatly accelerates the convergence speed of the TV *** simulation and experimental results demonstrate that compared to using the Newton-Raphson algorithm to solve the inverse problem of the TV regularization method,the proposed SB algorithm reduces the computing time by an average of 73.68% and 72.26% in simulation and experiment,respectively.

关键词： Ultrasonic transmission tomography image reconstruction inverse problems total variation split Bregman

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Online Identification of Boost Converter Components with Multiple Updating RLS Algorithm

Online Identification of Boost Converter Components with Mul...

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第42届中国控制会议

作者： Tong Zhou Zhicheng Zhang Zhiqiang Zuo Yijing Wang Peng Li Tianjin Key Laboratory of Intelligent Unmanned Swarm Technology and System School of Electrical and Information EngineeringTianjin University Key Laboratory of System Control and Information Processing Ministry of Education

In this paper,component parameters of the boost converter are identified online using a multiple updating recursive least squares(MURLS) *** component parameters,such as resistance,inductor inductance and capacitor capacitance,are obtained directly through the identification procedure rather than transfer function *** MURLS algorithm is applied to improve the rapidity of system identification compared to the traditional recursive least squares(RLS) algorithm,which is verified by a comparative simulation between MURLS and RLS and the simulation of a load-switching scenario.

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Toward Cable-Driven Continuum Robots: Micro-Motion Augmentation Using Eccentrically Arranged Fibres with Eccentric Lumens

Toward Cable-Driven Continuum Robots: Micro-Motion Augmentat...

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2024 IEEE International Conference on Robotics and Biomimetics, ROBIO 2024

作者： Lin, Zecai Zhou, Cheng Zou, Yun Gao, Anzhu Shanghai Jiao Tong University Institute of Medical Robotics Department of Automation China Key Laboratory of System Control and Information Processing Ministry of Education Shanghai200240 China Institute of Medical Robotics Shanghai Jiao Tong University Shanghai200240 China

ISBN: (纸本)9781665481090

Micro-motion augmentation of macro-motion continuum robot can largely enhance its micro-operation capability during surgery. However, most existing micro-motion continuum robots have non-compact mechanical structure or non-smooth micro tip motion, which leads to complicated control in micro lumens. This paper proposes a micro-motion augmentation method by rotating eccentrically arranged fibres with eccentric lumens for cable-driven continuum robots. Two thermal drawn polymer fibres with an eccentric lumen on each are inserted into its eccentric lumens of the continuum robot. The micro-motion mechanism relies on small changes in the neutral axis of the continuum robot due to the rotation of the eccentrically arranged fibres. A kinematic model considering variable neural axis is built to describe the micro motion, and a simulation is conducted to investigate the deformation characteristics. The resolution and micro motion with respect to different structural parameters are also analysed. Detailed experiments are performed to validate the effectiveness of the proposed method, and results indicate that the repeatability of micro-motion is 10.1 μm (4.0 %). © 2024 IEEE.

关键词： Robotic surgery

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Numerical modeling of droplets injection in the secondary flow of the wet steam ejector in the refrigeration cycle

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INTERNATIONAL JOURNAL OF REFRIGERATION 2022年 136卷 103-113页

作者： Dadpour, Daryoush Lakzian, Esmail Gholizadeh, Mohammad Ding, Hongbing Han, Xu [a]Center of Computational Energy Department of Mechanical Engineering Hakim Sabzevari University Sabzevar Iran [b]Tianjin Key Laboratory of Process Measurement and Control School of Electrical and Information Engineering Tianjin University Tianjin 300072 China [c]Key Lab of Condition Monitoring and Control for Power Plant Equipment North China Electric Power University Ministry of Education Baoding 071003 China

Steam ejector plays a key role in the refrigeration system. The water has been used as a working fluid because water is more economical and non-toxic. The operating fluid often enters the evaporator as a water liquid and droplets evaporate by absorbing heat. Cooling load changing causes the vapor in the outlet of the evaporator to be accompanied by droplets. Therefore, there are droplets at the inlet of secondary nozzle and flow should be simulated as a wet steam flow with injection droplets at the secondary flow. In this paper, the effects of droplets injection at secondary flow have been investigated on the performance of the refrigeration cycle. For this purpose, the Eulerian-Eulerian method has been used and the results have been validated with experimental data. Six cases are considered with different wetness and number of droplets in the secondary flow. The results of case 6 show COP, T-outlet, and ER decrease about 22.93%, 15.66%, and 22.93%, respectively. In addition, the steam accompanies by droplets at the outlet of ejector. Therefore, it is essential for designers and operators to model and consider the effects of the droplets on the wall erosion to optimize the wet steam ejector and refrigeration cycle performance.

关键词： Wet steam ejector Refrigeration cycle Droplets injection COP ER

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End-to-end Flow Scheduling Optimization for Industrial 5G and TSN Integrated Networks

End-to-end Flow Scheduling Optimization for Industrial 5G an...

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2024 IEEE Global Communications Conference, GLOBECOM 2024

作者： Liu, Houling Li, Mingyan Gu, Fuqiang Li, Qihao Zhang, Weiting Guo, Songtao Chongqing University College of Computer Science Chongqing400044 China Ministry of Education of China Key Laboratory of System Control and Information Processing Shanghai China Jilin University College of Communication Engineering Changchun130015 China Beijing Jiaotong University School of Electronic and Information Engineering Beijing100091 China

ISBN: (纸本)9798350351255

The integrated of the fifth generation (5G) and time-sensitive networking (TSN) is a promising approach to meet the requirements of deterministic forwarding with extremely low latency and high flexibility for the Industrial Internet of Things (IIoT). However, due to the large dissimilarity of protocol stacks, the 5G system normally serves as a logical bridge for TSN, performing hold-and-forward operations in Base Stations (BSs) under the current 5G-TSN frameworks. To provide ubiquitous and seamless connectivity for IIoT devices, this paper focuses on the integrated enhancement of 5G and TSN by optimizing the scheduling of time-sensitive flows with end-to-end latency of 5G-TSN transmission taken into consideration. Specifically, we propose a novel architecture named GF-CQF, which combines 5G Grant-free (GF) access with TSN Cyclic Queuing and Forwarding (CQF). Subsequently, the distributed flow scheduling problem based on GF-CQF architecture is established due to the high timeliness demands. To alleviate the impact of the uncertainty inherent in 5G channels on end-to-end deterministic transmission, a feature-aware decentralized real-time scheduling (FDRS) policy based on Multi-agent Reinforcement Learning is proposed. FDRS allows each agent at BS to adaptively allocate TSN injection slots for flows mainly based on dynamic 5G transmission performance and TSN network resource state so that TSN queue overflow can be avoided and flow delay constraints can be guaranteed. Simulations show that FDRS offers superior scheduling capabilities under the limited TSN queue resources. © 2024 IEEE.

关键词： 5G mobile communication systems

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A Depression Level Classification Model Based on EEG and GCN Network with Domain Generalization

A Depression Level Classification Model Based on EEG and GCN...

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第43届中国控制会议

作者： Zhongyi Zhang Chenyang Xu Licheng Jin Huirang Hou Qinghao Meng Tianjin Key Laboratory of Process Measurement and Control Institute of Robotics and Autonomous Systems School of Electrical and Information Engineering Tianjin University

ISBN: (数字)9789887581581

ISBN: (纸本)9798350366907

Electroencephalography(EEG) contains a wealth of information, including neuron activity, allowing for a partial understanding of the brain's state. As a reliable tool, EEG, combined with deep neural networks, has been increasingly utilized to assist in the detection of depression and has achieved satisfactory results. However, there are still some limitations in the current models. Firstly, it is worth noting that many existing models are binary classification models. These models can determine whether a subject is depressed or not, but they lack the capability to differentiate the severity of depression. Besides, the variations in EEG signals among various individuals have not been thoroughly taken into account, leading to subpar performance when applying the trained model to new subjects. To address the aforementioned issues, we suggest implementing a multi-classification model that utilizes a graph convolutional neural network(GCN) to identify levels of depression. Additionally,to mitigate the problem of imbalanced samples in multi-classification tasks, we introduce a penalty coefficient for the smaller categories. At the same time, the issue of signal discrepancies among subjects was taken into account, leading to the introduction of the domain generalization module. Finally, the depression level identification task on the MODMA and PRED+CT dataset achieved an accuracy of 75.47% and 77.97% respectively, surpassing the performance of the state-of-the-art(SOTA) model. In addition, numerous ablation experiments were conducted to validate the efficacy of each module.

关键词： Depression Level EEG Graph Convolution Network Domain Generalization

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Accelerated Simulation of Non-Markovian Quantum systems Using Quantum Trajectory 42

Accelerated Simulation of Non-Markovian Quantum Systems Usin...

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42nd Chinese control Conference, CCC 2023

作者： Wang, Yanfang Yue, Bo Xue, Shibei Department of Automation Shanghai Jiao Tong University Shanghai200240 China Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai200240 China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai200240 China

ISBN: (纸本)9789887581543

Quantum trajectory can be viewed as a numerical simulation method for wavefunctions which consume smaller memories compared to density matrices in master equations. In this paper, we adopt quantum trajectory to simulate the evolution of a non-Markovian quantum system modeled by an augmented system and further use parallel computing to improve efficiency. Compared to the Lindblad master equation solver in QuTiP, it can run more efficiently using less memory. In the example of a 8-spin-chain non-Markovian system, it only takes about 0.57% of the memory footprint and 4.12% of the runtime of the solver for the Lindblad master equation. © 2023 Technical Committee on control Theory, Chinese Association of Automation.

关键词： Quantum chemistry

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Improved Adaptive Variable Impedance control for Contact Force Tracking

Improved Adaptive Variable Impedance Control for Contact For...

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2023 IEEE International Conference on Real-Time Computing and Robotics, RCAR 2023

作者： Wei, Feili Gu, Chaochen Wu, Kaijie Cheng, Hao Department of Automation Shanghai Jiao Tong University Shanghai200240 China Ministry of Education of China Key Laboratory of System Control and Information Processing Shanghai200240 China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai200240 China

ISBN: (纸本)9798350327182

The utilization of impedance control is capable of achieving excellent force tracking performance. However, the balance between stability and flexibility is seldom considered in current methods. To address this issue, a novel adaptive variable impedance controller for contact force tracking is proposed in this study. Lyapunov theory is applied to develop an adaptive adjustment law of damping parameter in impedance control to enhance the robot's adaptability to uncertain environment and dynamic desired force. Additionally, a force compensator is designed based on direct adaptive control to expedite the response of force tracking. What sets this proposed method apart is that it does not require an accurate understanding of environmental parameters. Instead, it dynamically modifies the impedance parameters based on the force error to guarantee the stability and coordination of the system. Simulation results indicate that the proposed controller improves the flexibility and robustness of the force tracking capability of the robot system when compared to existing variable impedance control methods and effectively diminishes force overshoot. © 2023 IEEE.

关键词： Uncertainty analysis

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