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10th International Conference on Power Electronics, Machines and Drives, PEMD 2020

作者： Long, Jiang Yang, Ming Chen, Yangyang Ni, Qinan Xu, Dianguo State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781839535635

The inverter nonlinearity compensation has been studied by the researchers widely, however, due to the poor polarity detection ability of the discrete control system and unavoidable noises from current feedback, unideal compensation happens when the motor speed is low and the load is small. In order to tackle with this problem. This paper presents an inverter nonlinearity compensation method in permanent magnet synchronous motor (PMSM) drives. The overall process is achieved by voltage signal injection, the only requirements are stator resistance and the maximum current of a given motor. The corresponding voltage errors are saved in look up table (LUT) and being used together with field-oriented control (FOC). In addition, a comparative study when using phase current feedback, phase current reference and phase voltage reference for compensation voltages look-up in the already established LUT is conducted. A 750-W voltage-source inverter PMSM drive controlled by the FOC algorithm is used for experiment verification, the results show that the phase current reference is the most proper signal for compensation voltages look-up, especially around the current zero-crossing condition. The comparative study in this paper can be easily applied in the real industrial application with no hardware introduction and very little algorithm change. © PEMD *** right reserved.

关键词： Table lookup

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Dynamic Visual SLAM Based on Semantic Information and Multi-View Geometry 5

Dynamic Visual SLAM Based on Semantic Information and Multi-...

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5th International Conference on Automation, Control and robotics Engineering, CACRE 2020

作者： Shi, Junyi Zha, Fusheng Guo, Wei Wang, Pengfei Li, Mantian Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9781728198880

Visual Simultaneous Localization and Mapping (Visual SLAM) is considered to be one of the important foundations for mobile robots to move toward intelligence, which gives robots the ability to autonomously locate and construct maps in an unknown environment. In the past decades, great progress has been made in the field of visual SLAM, relatively mature algorithm system and program architecture are gradually developed. However, the current researches on visual SLAM mostly assume that the surrounding environment is static, which greatly limits the application of SLAM systems in real world. Aiming at the urgent need of mobile robots for precise localization and map construction in dynamic environment, methods are proposed in this paper. Image semantic segmentation based on deep learning and multi-view geometry methods are combined to recognize and segment moving objects. Only background features are used for camera tracking to avoid the impact of moving objects. Furthermore, an experimental platform is built using RGB-D camera and motion capture device, the effectiveness of the algorithm is verified by public datasets and real scene data. © 2020 IEEE.

关键词： Semantics

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Semi-Autonomous Navigation Based on Local Semantic Map for Mobile Robot

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Journal of Shanghai Jiaotong university(Science) 2025年第1期30卷 27-33页

作者： ZHAO Yanfei XIAO Peng WANG Jingchuan GUO Rui Department of Automation Institute of Medical RoboticsShanghai Jiao Tong UniversityShanghai200240China State Key Laboratory of System Control and Information Processing Ministry of Education of ChinaShanghai200240China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai200240China State Grid Intelligence Technology Co. Ltd.Jinan250013China

Mobile robots represented by smart wheelchairs can assist elderly people with mobility *** paper proposes a multi-mode semi-autonomous navigation system based on a local semantic map for mobile robots,which can assist users to implement accurate navigation(e.g.,docking)in the environment without prior *** order to overcome the problem of repeated oscillations during the docking of traditional local path planning algorithms,this paper adopts a mode-switching method and uses feedback control to perform docking when approaching semantic *** last,comparative experiments were carried out in the real *** show that our method is superior in terms of safety,comfort and docking accuracy.

关键词： semi-autonomous navigation mobile robot semantic map voice interaction

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Imitation of Manipulation Skills Using Multiple Geometries

arXiv

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arXiv 2022年

作者： Ti, Boyang Gao, Yongsheng Zhao, Jie Calinon, Sylvain State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Idiap Research Institute MartignyCH-1920 Switzerland

Daily manipulation tasks are characterized by geometric primitives related to actions and object shapes. Such geometric descriptors are poorly represented by only using Cartesian coordinate systems. In this paper, we propose a learning approach to extract the optimal representation from a dictionary of coordinate systems to encode an observed movement/behavior. This is achieved by using an extension of Gaussian distributions on Riemannian manifolds, which is used to analyse a set of user demonstrations statistically, by considering multiple geometries as candidate representations of the task. We formulate the reproduction problem as a general optimal control problem based on an iterative linear quadratic regulator (iLQR), where the Gaussian distribution in the extracted coordinate systems are used to define the cost function. We apply our approach to object grasping and box opening tasks in simulation and on a 7-axis Franka Emika robot. The results show that the robot can exploit several geometries to execute the manipulation task and generalize it to new situations, by maintaining the invariant characteristics of the task in the coordinate system(s) of interest. Copyright © 2022, The Authors. All rights reserved.

关键词： Geometry

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The impact of microplastics and nanoplastics on biological nitrogen removal processes: Exacerbating the greenhouse effect

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Journal of Hazardous Materials 2025年 494卷 138696页

作者： Zhu, Yuliang Ma, Ben Li, Dong Liu, Tongshuai Zhu, Yanjun Zeng, Huiping Zhang, Jie Key Laboratory of Water Science and Water Environment Recovery Engineering Beijing University of Technology Beijing100124 China State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian116024 China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin150090 China

The widespread presence of microplastics/nanoplastics (MPs/NPs) in various environments poses a significant threat to the ecological environment. Wastewater treatment plants (WWTPs) serve as significant reservoirs of MPs/NPs, wherein a substantial quantity of these are adsorbed by activated sludge in the biological treatment system and continuously accumulated, thereby jeopardizing the stable operation of biological nitrogen removal (BNR) processes. Consequently, it is imperative to comprehensively summarize the impacts of MPs/NPs on BNR process performance and elucidate their underlying mechanisms of action. This review paper provides an overview of the sources and types of MPs/NPs found in WWTPs, examines their effects on different BNR processes, and summarizes several inhibition mechanisms associated with MPs/NPs exposure. The findings indicate that the inhibitory effect exerted by MPs/NPs on BNR processes is closely correlated with their polymer type, size, concentration, and duration of exposure. Anaerobic ammonium oxidation processes exhibit higher sensitivity towards MP/NP exposure. Furthermore, analysis reveals that MPs/NPs influence microbial activity through protein secretion inhibition, competition for substrate adsorption sites, obstruction of substrate transport channels, attenuation of extracellular electron transfer processes, and induction of reactive oxygen species production. Additionally, MPs/NPs will expedite the migration of toxic and deleterious substances, such as heavy metals and antibiotics, towards microbes. Finally, molecular docking simulation experiments demonstrate that PS-MPs exhibit superior binding energy with key enzymes involved in nitrogen removal functionality. Nor functional enzymes display high binding energy levels when interacting with diverse types of MPs. The presence of MPs/NPs leads to accumulation of NO and N2O, greatly exacerbating the greenhouse effect. The article offers new insights into the impact of MPs/NPs on BNR

关键词： Nitrogen removal

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A Kind of Kinematics Modeling of 2 DOFs Notched Continuum Manipulator 7

A Kind of Kinematics Modeling of 2 DOFs Notched Continuum Ma...

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7th International Conference on Information Science and Control Engineering, ICISCE 2020

作者： Wang, Xiaolong Yan, Zhiyuan Wang, Haodong Gao, Yongzhuo Du, Zhijiang Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9781728164069

It's difficult for traditional rigid manipulators to complete relevant operations in the single port laparoscopic. The notched continuum manipulator owns the features of flexibility and biocompatibility which can make it possible applied in the single port laparoscopic. A kinematics modeling similar to the constant-curvature approximations is proposed in this paper. It can be utilized to describe the mapping relationship between the length change value of two driven wires and the end position. This method simplifies the complexity of kinematic modeling. And it makes the control method of the continuum manipulator easier to achieve as well. The accuracy of the model has been verified by the prototype. © 2020 IEEE.

关键词： Manipulators

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Flow Mixing Characteristics in Double Loop Reactor Pressure Vessel Under Accident Conditions 29

Flow Mixing Characteristics in Double Loop Reactor Pressure ...

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2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Xie, Guanhui Li, Runcheng Wei, Tianyi Lin, Zhikang Li, Dongyang Tan, Sichao Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China Nuclear Power Technology Research Institute of China Guangdong Shenzhen518000 China

ISBN: (纸本)9780791886502

In case of core emergency cooling safety injection, the boron containing coolant injected externally and dilution water mass will be mixed in the pressure vessel. The uneven mixing of boron containing coolant and dilution water mass may lead to the return of the core to criticality. Therefore, it is of great significance to accurately measure the boron concentration distribution in the pressure vessel and study the mechanism affecting the mixing process for the safe operation of the reactor. In this paper, combined with the structural characteristics of HPR1000 pressure vessel, a visual experimental device is built through proportional modeling design, and the flow mixing process of diluted water mass, safety injection solution and coolant in the pressure vessel under double loop operation is obtained by using plane laser-induced fluorescence technology, the effects of different Reynolds numbers on the diffusion of boric acid were experimentally studied. The experimental results show that under the condition of double loop, the two inlets divide the circumferential direction into good arc and bad arc. The velocity distribution of fluid flowing through the bad arc is more uniform, while the vertical flow of fluid flowing through the good arc is uneven;The fluid flows downward rapidly after the intersection on the inferior arc side, and the intersection height is positively correlated with the cold pipe flow, while the fluid on both sides shows obvious mixing after the intersection on the superior arc side;Clear water mass cannot be avoided at the core inlet, but increasing the cold pipe flow and safety injection flow can reduce the time of clear water mass flowing through the core. © 2022 by ASME.

关键词： Mixing

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Offline Deep Reinforcement Learning Two-stage Optimization Framework Applied to Recommendation systems

Offline Deep Reinforcement Learning Two-stage Optimization F...

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第43届中国控制会议

作者： Yihua Jiang Qi Liu Yanjie Li Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics and School of Mechanical Engineering and Automation the Harbin Institute of Technology

ISBN: (数字)9789887581581

ISBN: (纸本)9798350366907

Most traditional recommendation systems(RS) improve the model structure to obtain valid user behavior representation and make better recommendations. However, limited by the scale of the model, the model cannot accommodate an extended range of user historical data and cannot effectively extract long-term preferences. Reinforcement learning(RL) aims to maximize the cumulative return. Introducing RL can smoothly solve the long-term and short-term profit balance. However, there are specific problems with the direct combination of the two. Training RS that relies on offline user data will cause the strategy to suffer from an overestimation of action and distribution shift. Unlike the traditional RL environment, the ample space of the RS will also cause problems of insufficient exploration and sparse rewards, making the policy more difficult to learn. In response to the above issues, this work proposes an offline RL two-stage optimization framework. The framework consists of an offline RL method based on unknown behavior to alleviate the problem of action overestimation and a two-stage feature optimization training method to reduce the impact of large spaces. Experimental results prove that the method proposed in this article can effectively improve the long-term recommendation ability of the model and more effectively improve the model performance than the general offline RL algorithm.

关键词： Recommendation systems Overestimation of Actions Distribution Shift Deep Reinforcement Learning Two-stage Feature Optimization

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An Anti-jamming Algorithm for GNSS Receiver with Null Phase Shift and Delay 4

An Anti-jamming Algorithm for GNSS Receiver with Null Phase ...

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4th IEEE International Conference on Civil Aviation Safety and Information technology, ICCASIT 2022

作者： Baoguo, Yu Fang, Hao Shaobo, Xu State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang China College of Intelligent Science and Engineering Harbin Engineering University Harbin China

ISBN: (数字)9781665467667

ISBN: (纸本)9781665467667

Aiming at the carrier offset and code phase shift problems caused by the space-time anti-jamming algorithm in the navigation and positioning receiver measurement. This paper proposes a distortion-free STAP that constrain the coefficients of the space-time processor to ensure linearity of its response. In addition, the structure of STAP filter is modified so that the output delay is zero. Interferences can not only be suppressed to ensure the reception of GNSS signals, but also code and carrier phase shift will not be introduced. Moreover, the proposed strategy can be matched with a general receiver. © 2022 IEEE.

关键词： Space time adaptive processing

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Design of tunable laser drive and temperature control system based on FPGA 4

Design of tunable laser drive and temperature control system...

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4th IEEE International Conference on Data Science and Computer Application, ICDSCA 2024

作者： Yu, Guolin Huang, Lei Zhang, Tianqi Harbin Institute of Technology Weihai Weihai China Wuhan Technology and Business University Wuhan China Key Laboratory of Luminescence Science and Technology Chinese Academy of Sciences State Key Laboratory of Luminescence Science and Applications Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun China University of Chinese Academy of Sciences Beijing China

ISBN: (纸本)9798350368239

Based on the operational principles of field-programmable gate arrays (FPGA) and laser diodes, we have designed and constructed a semiconductor laser driver circuit. The temperature control and feedback circuit employ high-speed MOSFETs as switching devices to drive the laser diodes. Utilizing LTspice simulation software, we analyzed the impact of supply voltage, energy storage capacitor, and damping resistor on the driving pulse in the laser driver circuit, ultimately selecting optimal circuit parameters. This circuit meets the design requirements for high-current nanosecond pulse semiconductor laser driver circuits. Through interaction with an upper computer system, it is possible to continuously adjust the laser's drive current and operating temperature to ensure that the output wavelength of the semiconductor laser falls within an optimal range. Following testing, this temperature-controlled semiconductor laser driver system fully satisfies practical application needs and effectively resolves issues related to unstable wavelength and power caused by fluctuations in the working temperature of the semiconductor laser. ©2024 IEEE.

关键词： Semiconductor lasers

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