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Steady-state and dynamic simulation of gas phase polyethylene process

Chinese Journal of Chemical Engineering 2024年第11期75卷 110-120页

作者： Xiaodong Hong Wanke Chen Zuwei Liao Xiaoqiang Fan Jingyuan Sun Yao Yang Chunhui Zhao Jingdai Wang Yongrong Yang State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China Engineering Research Center of Functional Materials Intelligent Manufacturing of Zhejiang Province ZJU-Hangzhou Global Scientific and Technological Innovation CenterHangzhou 311215China Ningbo Research Institute Zhejiang UniversityNingbo 315100China State Key Laboratory of Industrial Control Technology College of Control Science and EngineeringZhejiang UniversityHangzhou 310027China

Gas-phase polyethylene(PE)processes are among the most important methods for PE production.A deeper understanding of the process characteristics and dynamic behavior,such as properties of PE and reactor stability,holds substantial interest for both academic researchers and *** this study,both steady-state and dynamic models for a gas-phase polyethylene process are established as a simulation platform,which can be used to study a variety of operation tasks for commercial solution polyethylene processes,such as new product development,process control and real-time *** copolymerization kinetic parameters are fitted by industrial ***,a multi-reactor series model is developed to characterize the temperature distribution within the fluidized bed *** accuracy in predicting melt index and density of the polymer,and the dynamic behavior of the developed models are verified by real plant ***,the dynamic simulation platform is applied to compare four practical control schemes for reactor temperature by a series of simulation experiments,since temperature control is important in industrial *** results reveal that all four schemes effectively track the setpoint ***,only the demineralized water temperature cascade control demonstrates excellent performance in handling disturbances from both the recycle gas subsystem and the heat exchange subsystem.

关键词： Gas-phase polyethylene process Steady state Dynamic modeling control

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Object Detection with Depth Information in Road Scenes 8th

Object Detection with Depth Information in Road Scenes

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8th International Conference on Cognitive Systems and Information Processing, ICCSIP 2023

作者： Liu, Ruowang Chen, Xinbo Tao, Bo Key Laboratory of Metallurgical Equipment and Control Technology Ministry of Education Wuhan University of Science and Technology Wuhan China Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of Science and Technology Wuhan China Precision Manufacturing Institute Wuhan University of Science and Technology Wuhan China Research Center for Biomimetic Robot and Intelligent Measurement and Control Wuhan University of Science and Technology Wuhan China

ISBN: (纸本)9789819980208

In recent years, depth estimation has witnessed significant advancements because of the development of deep learning. It's important to note that depth estimation tasks focus solely on predicting the depth of each pixel in an image and do not include object detection or object recognition. Depth estimation is the use of pixel transformations in the image to obtain distance information from each point in the scene to the camera to generate a depth map. Object detection is the process of classifying and localizing an image, given a picture, so as to identify the objects in the picture and determine their location. To overcome this limitation and integrate object detection into the depth estimation process, this paper proposes a novel self-supervised monocular depth estimation algorithm that leverages an attention mechanism. By combining object detection and depth estimation, a real-time multi-task model is designed to enable simultaneous detection and depth estimation of objects. The framework comprises four essential components: an object detection sub-network, a depth estimation sub-network, a lateral sharing unit, and an attention loss. These components work collaboratively to enhance distance estimation accuracy for objects and improve the object detection performance. Throughout experiments, it is evident that the proposed approach can effectively estimate distances to objects and enhances the accuracy of object detection. © 2024, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Object detection

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Research on Meshing Characteristics and Vibration of Aluminum Miner Based on MASTA 14th

Research on Meshing Characteristics and Vibration of Aluminu...

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14th International Workshop of Advanced Manufacturing and Automation, IWAMA 2024

作者： Dong, Guanzhan Xu, Weipeng Gao, Kuidong College of Mechanical and Electronic Engineering Shandong University of Science and Technology Qingdao266590 China State Key Laboratory of Intelligent Coal Mining and Strata Control Shanghai China

ISBN: (纸本)9789819626243

Aiming at the mechanical continuous operation of bauxite mining process, firstly, an improved scheme of cutting bauxite with an 8-pole motor shearer is proposed, which is practical and feasible, and a 3D model is established in Solid Edge. Secondly, considering the higher meshing frequency of high-speed gear in the cutting part, the meshing characteristics under different loads were investigated by MASTA software, and the laws of contact stress, meshing dislocation and trans-mission error were obtained. Finally, the vibration displacement of one axis is obtained in view of the significant influence of individual order energy on the vibration of the shell under rated working conditions. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Bauxite deposits

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Study on Disturbing Moment Compensation for the Satellite with Large-Scale Rotating Antennas 8th

Study on Disturbing Moment Compensation for the Satellite wi...

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8th International Conference on Signal and Information Processing, Network and Computers, ICSINC 2021

作者： Fan, Wei Zhang, Yin Zeng, Haibo Beijing Institute of Control Engineering Beijing100190 China Science and Technology on Space Intelligent Control Laboratory Beijing100190 China Institute of Telecommunication and Navigation Satellites China Academy of Space Technology Beijing100094 China

ISBN: (纸本)9789811933868

In this paper, a method of interference feedforward compensation is proposed for the disturbance of satellites with large rotating antenna such as relay satellites with Large-scale Rotating Antennas. This method utilizes the angular momentum exchange device in advance to pre-compensate In order to reduce the disturbance of the satellite by calculating the coupling angular momentum changes of the satellite caused by the antenna motion at different positions. The simulation results show that the method can effectively reduce the interference of satellite when antennas do large-scale rotating which can make the attitude of the satellite more stable and the directional fluctuation of the platform smaller, which is conducive to the normal work of other satellite loads. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Satellites

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CNS/INS Integrated Navigation Method Based on Improved Adaptive CKF Algorithm 49

CNS/INS Integrated Navigation Method Based on Improved Adapt...

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49th Annual Conference of the IEEE Industrial Electronics Society, IECON 2023

作者： Wang, Dong Yang, Jing Xiong, Kai Li, Wenling School of Automation Science and Electrical Engineering Beijing University of Aeronautics and Astronautics Beijing China Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering Beijing China

ISBN: (纸本)9798350331820

Aiming at the problem that measurement model uncertainty restrains navigation accuracy in the celestial/ inertial (CNS/INS) integrated navigation system, a kind of CNS/INS integrated navigation method based on improved adaptive cubature Kalman filter (CKF) is proposed. In order to mitigate the influence of installation error and axis disturbance error of star camera, angular distance between starlight vector of stars and line of sight vector of space targets is employed to establish the measurement model;the measurement noise covariance matrix (MNCM) is estimated online to lower the model uncertainty;adaptive adjustment coefficient is constructed based on squared Mahalanobis distance (SMD) of measurement innovation to adjust forgetting factor online to further improve robustness and adaptability of the method. Simulation results demonstrate that the proposed method can achieve higher navigation accuracy compared to standard and classical method under measurement model mismatch. © 2023 IEEE.

关键词： Uncertainty analysis

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A Dual Network Approach with Enhanced Feature Guidance for SAR-to-Optical Image Translation 2

A Dual Network Approach with Enhanced Feature Guidance for S...

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2nd IEEE International Conference on Signal, Information and Data Processing, ICSIDP 2024

作者： He, Jingfei Mao, Yongfei Zhao, Liangbo Cui, Zihan Wang, Yu Shi, Hao Beijing Institute of Technology National Key Laboratory of Science and Technology on Space-Born Intelligent Information Processing Beijing China China Academy of Space Technology Institute of Remote Sensing Satellite Beijing China China Academy of Space Technology Beijing Institute of Space Mechanics and Electricity Beijing China

ISBN: (纸本)9798331515669

Synthetic Aperture Radar (SAR) images own dominant merits, such as all-weather and all-day working conditions, but it is difficult for unprofessional people to interpret SAR images. Translating SAR images into optical images to assist interpretation can facilitate the transformation of SAR data into usable information. Therefore, an advanced SAR to Optical (S2O) image translation method utilizing a parallel Generative Adversarial Network (GAN) framework was proposed. This method incorporates an optical image reconstruction network alongside the S2O translation network, enhancing the fidelity and color consistency of the translated images. By employing a domain alignment module and a deep supervision feature loss module, the network effectively utilizes abundant optical image features to overcome the scarcity of SAR-optical image pairs. Experiments conducted on the SEN1-2 dataset demonstrate superior performance over existing methods, particularly in preserving detailed structural information in images. © 2024 IEEE.

关键词： Generative adversarial networks

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Improvement of VMD and Compensation Distance for Rolling Bearing Fault Detection Methods 43

Improvement of VMD and Compensation Distance for Rolling Bea...

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43rd Chinese control Conference, CCC 2024

作者： Guo, Kai Xiong, Xin Ma, Jun Kunming University of Science and Technology Faculty of Information Engineering and Automation Kunming650500 China Kunming University of Science and Technology Key Laboratory of Intelligent Control and Application of Yunnan Province Kunming650500 China

ISBN: (纸本)9789887581581

To address the problem of varying detection performance and the lack of universal standards for early fault detection in rolling bearings, a method for early fault detection in rolling bearings based on an improved variational modal decomposition (IVMD) and compensation distance (CD) is proposed from the perspective of constructing performance degradation curves. Firstly, the number of modes K for variational mode decomposition (VMD) is adaptively determined using the estimated signal-to-noise ratio (eSNR) method. Secondly, the probability density function (PDF) distribution of the intrinsic mode function (IMF) obtained from the decomposition is calculated, and the compensation distance (CD) degradation evaluation index is constructed by integrating the inter-class and intra-class distances. Then, a sliding window is used to repair the false fluctuations in the CD degradation index based on linear regression equations and the 3 σ principle, resulting in a sensitive degradation index that accurately characterizes the rolling bearing degradation process Improved Compensation Distance (ICD). Finally, the Chebyshev inequality is used to establish the relationship between the healthy threshold and the ICD index, enabling early fault detection in rolling bearings. Comparative analysis of one set of experiments shows that the proposed method can accurately characterize the degradation process of rolling bearings and effectively detect early faults, providing a new solution for early fault diagnosis of bearings. © 2024 Technical Committee on control Theory, Chinese Association of Automation.

关键词： Probability density function

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Learning-Observer-Based Adaptive Tracking control of Multiagent Systems Using Compensation Mechanism

IEEE Transactions on Artificial Intelligence

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IEEE Transactions on Artificial Intelligence 2024年第1期5卷 358-369页

作者： Li, Zhiqiang Liu, Yang Ma, Hui Li, Hongyi Guangdong University of Technology School of Automation and Guangdong Province Key Laboratory of Intelligent Decision and Cooperative Control Guangzhou510006 China Qingdao University of Science and Technology School of Automation and Electronics Engineering Qingdao266061 China Guangdong University of Technology School of Mathematics and Statistics Guangzhou510006 China

This article focuses on the adaptive consensus tracking problem for nonlinear multiagent systems with unmeasurable state and input saturation. For unmeasurable state and nonlinearities, a learning-observer inspired by the idea of extended state observer and the learning ability of neural network are established to observe the reconstructed system. In view of input saturation, a nonlinear auxiliary system with the same order is constructed to obtain the compensation signals. Different from the previous auxiliary system, the proposed method simultaneously compensates the change of nonlinearity caused by input saturation. Subsequently, a consensus tracking error is designed to ensure that the follower tracks the neighbor compensated output. Moreover, an adaptive consensus tracking control method based on learning-observer and compensation mechanism is proposed under the backstepping framework. The stability analysis is given by virtue of the Lyapunov theory. Finally, the effectiveness and superiority of the proposed control algorithm are verified through the simulation of unmanned air vehicles with one virtual leader and four followers. © 2020 IEEE.

关键词： Neural networks

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A multi-source data fusion navigation method of spacecraft with limited GNSS signals

A multi-source data fusion navigation method of Spacecraft w...

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第十四届中国卫星导航年会

作者： Leyao Li Jiansong Chang Jianxin Guo Beijing Institute of Control Engineering Science and Technology on Space Intelligent Control Laboratory

Global Navigation Satellite system(GNSS) is initially designed to provide services to objects on the earth surfaces, or in the earth-orbits with altitude below 3000 km. However, previous researches show that GNSS receivers mounted on GEO satellites can receive GNSS signals and generate positioning and navigation results as well. Considering that in some harsh situations, such as bad observation geometry, weak signal acquisition, etc., the on-board GNSS receivers can only transfer pseudo-range data to GEO satellites, this paper proposed an autonomous navigation method in which the information from GNSS receiver, optical attitude sensors, and inter-satellite links are fused together: at first, the extended state equation and measurement equation of a GEO satellite with optical sensor's errors are deduced;then, an extended Kalman filter is designed to evaluate and compensate optical sensor's errors via constructed earthcentered vector bias;later, a sequential correction is carried out using intersatellite link measurements;finally, the performance of proposed method is analyzed through Monte-Carlo simulation. It shows that the average distance and velocity evaluation errors of proposed method are around 0.2 Km and 0.05 m/s individually;the performance can meet the requirements of survivability of a class of high-orbit, long-life and high-value satellites.

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Distributed formation-aggregation control algorithm for a cluster of quadrotors

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Journal of the Franklin Institute 2023年第3期360卷 1560-1581页

作者： Sun, Yongbin Li, Jiayi Wang, Zixuan He, Xiuyu Fu, Qiang Zou, Yao School of Automation Science and Electrical Engineering Beihang University Beijing100191 China School of Intelligence Science and Technology University of Science and Technology Beijing Beijing100083 China Key Laboratory of Perception and Control of Intelligent Bionic Unmanned Systems Ministry of Education University of Science and Technology Beijing Beijing100083 China

This paper focuses on the solution to a formation-aggregation problem concerned with a cluster of quadrotors. In particular, all the quadrotors are steered towards a target region while reaching an expected formation configuration. However, only a subset of quadrotors, treated as leaders, have access to the projections onto the target region;and in the meantime, each quadrotor just exchanges information with its neighbors. It is assumed that the quadrotors without the knowledge of the target region, treated as followers, are within the convex hull of the leaders in the expected configuration. A distributed formation-aggregation control algorithm is proposed under the hierarchical framework. To be specific, resorting to an auxiliary dynamic system with a distributed idea, a command force is first synthesized in the position loop for the concerned formation-aggregation objective. Next, an applied thrust and a command attitude are extracted from the synthesized command force. Finally, an applied torque is synthesized in the attitude loop such that the attitude tracking to the command one is realized. In terms of the Lyapunov theory, it is shown that the leaders are capable of guiding the overall quadrotor cluster into the target region in the expected configuration. Simulations are carried out to validate the theoretical results. © 2022 The Franklin Institute

关键词： Computer networks

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