检索结果-内蒙古大学图书馆

arXiv 2023年

作者： Wang, Tianyu Yang, Yannian Chen, Xuanwu Li, Pengyu Iollo, Angelo Maceda, Guy Cornejo Y. Noack, Bernd R. School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen518055 China Key Laboratory of Autonomous Systems and Networked Control Ministry of Education Unmanned Aerial Vehicle Systems Engineering Technology Research Center of Guangdong School of Automation Science and Engineering South China University of Technology Guangzhou510640 China Institute of Aero Engine Tsinghua University Beijing10084 China Department of Mechanics and Aerospace Engineering Southern University of Science and Technology Shenzhen518055 China Institut de Mathématiques de Bordeaux Université de Bordeaux and Memphis Team Centre Inria de l’Université de Bordeaux Talence33400 France

We develop and apply a novel shape optimization exemplified for a two-blade rotor with respect to the figure of merit (FM). This topologically assisted optimization (TAO) contains two steps. First a global evolutionary optimization is performed for the shape parameters and then a topological analysis reveals the local and global extrema of the objective function directly from the data. This non-dimensional objective function compares the achieved thrust with the required torque. Rotor blades have a decisive contribution to the performance of quadcopters. A two-blade rotor with pre-defined chord length distribution is chosen as the baseline model. The simulation is performed in a moving reference frame with a k−ω turbulence model for the hovering condition. The rotor shape is parameterized by the twist angle distribution. The optimization of this distribution employs a genetic algorithm. The local maxima are distilled from the data using a novel topological analysis inspired by discrete scalar-field topology. We identify one global maximum to be located in the interior of the data and five further local maxima related to errors from non-converged simulations. The interior location of the global optimum suggests that small improvements can be gained from further optimization. The local maxima have a small persistence, i.e., disappear under a small Ε perturbation of the figure of merit values. In other words, the data may be approximated by a smooth mono-modal surrogate model. Thus, the topological data analysis provides valuable insights for optimization and surrogate modeling. Copyright © 2023, The Authors. All rights reserved.

关键词： Turbulence models

来源：评论

学校读者我要写书评

暂无评论

Online Parameter Estimation For Uncertain Robot Manipulators With Fixed-time Convergence

Online Parameter Estimation For Uncertain Robot Manipulators...

引用

IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： Chengzhi Zhu Yiming Jiang Chenguang Yang Key Laboratory of Autonomous Systems and Networked Control College of Automation Science and Engineering South China University of Technology Guangzhou China National Engineering Laboratory for Robot Visual Perception and Control Hunan University Changsha China Bristol Robotics Laboratory University of the West of England Bristol UK

ISBN: (数字)9781728151694

ISBN: (纸本)9781728151700

For traditional parameter estimation schemes of uncertain robot, most of them were proposed to identify unknown parameter with desired precision, but few of them focused on the convergence time. Recently finite-time estimation techniques have been proposed by scholars to achieve estimation in finite time. In this paper, we proposed a novel estimation scheme for uncertain robot systems with fixed time instead of finite time. In order to avoid using acceleration signals during the estimation, a kind of auxiliary filtering technique was employed. Besides, a continuous and recursive update law was employed for the parameter estimation such that the computational burdens of real-time inversion of square matrices could be avoided. Finally the effectiveness of the identification algorithm is verified based on a 2-DOF uncertain robot model.

关键词： Parameter estimation Filtering Heuristic algorithms Estimation Real-time systems Manipulator dynamics Convergence

来源：评论

学校读者我要写书评

暂无评论

OD-SLAM: Real-Time Localization and Mapping in Dynamic Environment through Multi-Sensor Fusion

OD-SLAM: Real-Time Localization and Mapping in Dynamic Envir...

引用

International Conference on Advanced Robotics and Mechatronics (ICARM)

作者： Hua Xu Chenguang Yang Zhijun Li Key Laboratory of Autonomous Systems and Networked Control College of Automation Science and Engineering South China University of Technology Guangzhou China School of Information Science and Technology University of Science and Technology of China Anhui China

ISBN: (数字)9781728164793

ISBN: (纸本)9781728164809

Only when the robot knows its position can it execute some specific functions. But in many cases, the robot faces an unknown environment and doesn't know where it is. Visual SLAM system uses the camera on the robot to capture the image of the surrounding environment for positioning. This is a method that relies on external information for positioning. When the external information is dynamic, the pose estimated by the traditional visual SLAM system is inaccurate. So a novel SLAM system is proposed in this paper, which mainly uses a neural network and multi-sensor fusion to realize robot positioning in a dynamic environment. The SLAM system is developed based on ORB-SLAM2. It recognizes highly dynamic objects in the image through the neural network and removes them from the image. Because the neural network can't accurately identify dynamic objects every time, it will affect the pose estimation of the SLAM system. Therefore, the SLAM system proposed in this paper uses odometer to constrain features extracted in the image, so as to obtain static features, and finally estimate a more accurate pose. Finally, the experimental results show that our system has better real-time and accuracy compared with the traditional visual SLAM systems and other dynamic SLAM systems.

关键词： Feature extraction Simultaneous localization and mapping Visualization Vehicle dynamics Semantics Real-time systems

来源：评论

学校读者我要写书评

暂无评论

VFH∗ Based Local Path Planning for Mobile Robot 2

VFH∗ Based Local Path Planning for Mobile Robot

引用

2nd China Symposium on Cognitive Computing and Hybrid Intelligence, CCHI 2019

作者： Chen, Wenqiang Wang, Ning Liu, Xiaofeng Yang, Chenguang Key Laboratory of Autonomous System and Networked Control College of Automation Science and Engineering South China University of Technology Guangzhou510640 China Bristol Robotics Laboratory University of the West of England BristolBS16 1QY United Kingdom Changzhou Key Laboratory of Robotics and Intelligent Technology College of Internet of Things Engineering Hohai University Changzhou213022 China

ISBN: (纸本)9781728140919

Vector Field Histogram(VFH) and its variants are effective obstacles avoidance method for mobile robots. Under the more consideration of realistic, we proposed a new local path planning method for mobile robot in this paper. The proposed method takes global path point generated by the A∗ algorithm as temporary target point and adopts the basic concepts of the VFH∗ algorithm, the difference is mainly lies in the representation of vector magnitude of the obstacles, the determination of the threshold, the selection of the candidate direction, and the definition of the node cost function in search tree. Besides, according to the optimal obstacle avoidance direction obtained in the above steps, we also give a speed control method to control the movement of the omnidirectional mobile robot to the target point. Simulation and experiment results shows that the proposed method is suited for mobile robot moving in realistic situation. © 2019 IEEE.

关键词： Mobile robots

来源：评论

学校读者我要写书评

暂无评论

Observer-based Dynamic Surface control for Robotic Manipulator with Fixed-time Convergence

Observer-based Dynamic Surface Control for Robotic Manipulat...

引用

International Conference on Informative and Cybernetics for Computational Social systems (ICCSS)

作者： Chengzhi Zhu Lei Zuo Ning Wang Key Laboratory of Autonomous Systems and Networked Control College of Automation Science and Engineering South China University of Technology Guangzhou China School of Electronic and Control Engineering Chang'an University Xi'an China School of Information Engineering Chang'an University Xi'an China

ISBN: (数字)9781728162461

ISBN: (纸本)9781665419352

A state feedback dynamic surface tracking control algorithm is proposed for parametric linearized manipulator model in this paper. Different from ordinary finite-time control schemes, fixed-time convergence can be achieved in the proposed algorithm via both of high and low-degree terms in the controller such that the settling time can be preestablished by the designed parameters independent of the system initial conditions. Moreover, the problem of the “explosion of complexity” and the singularity can be avoided by constructing an auxiliary controller with a first-order filter. The semi-global fixed-time uniform convergence of all the signals in the closed-loop system can be proved by Lyapunov theorem. In order to avoid the employment of acceleration signals and obtain better tracking performance during the procedure, a kind of observer based on uniform exact differentiators was used to compensate the uncertainties online. Finally the superiority of the proposed method has been verified by simulations based on a 2-DOF robot manipulator.

关键词： Maximum likelihood detection Heuristic algorithms Nonlinear filters Observers Explosions Manipulator dynamics Convergence

来源：评论

学校读者我要写书评

暂无评论

Distributed Observer Design for Achieving Asymptotical Omniscience over Time-variant Disconnected Networks ⁎

引用

IFAC-PapersOnLine 2020年第2期53卷 3565-3570页

作者： Haotian Xu Jingcheng Wang Hongyuan Wang Shangwei Zhao Hai Lin Department of Automation Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai 200240 China Autonomous Systems and Intelligent Control International Joint Research Center Xi’an Technological University Xi’an Shaanxi 710021 China

This paper investigates the distributed observer design for linear system under time-variant disconnected communication network. By constructing basic eigenvectors of 0-eigensubspace of disconnected Laplacian Matrix and using LMIs method, we prove the distributed observer cannot achieve omniscience asymptotically under switching topology without constraining the system matrix or alternative topologies set. To deal with this problem, this paper investigates three kinds of constraints and the system matrix only needs to satisfy any one of them. Then a group of sufficient conditions corresponding to the asymptotic omniscience of distributed observer under switching topology are proved by Lyapunov analysis. Finally, a numerical simulation shows the validity of our method.

关键词： Distributed observer Continuous time system estimation Consensus Sensor networks Switching topology

来源：评论

学校读者我要写书评

暂无评论

Domain-invariant similarity activation map contrastive learning for retrieval-based long-term visual localization

arXiv

引用

arXiv 2020年

作者： Hu, Hanjiang Wang, Hesheng Liu, Zhe Chen, Weidong Autonomous Robot Lab Department of Automation Key Laboratory of System Control and Information Processing Ministry of Education Shanghai Jiao Tong University Shanghai200240 China The State Key Laboratory of Robotics and System HIT The Department of Computer Science and Technology University of Cambridge United Kingdom

Visual localization is a crucial component in the application of mobile robot and autonomous driving. Image retrieval is an efficient and effective technique in image-based localization methods. Due to the drastic variability of environmental conditions, e.g. illumination, seasonal and weather changes, retrieval-based visual localization is severely affected and becomes a challenging problem. In this work, a general architecture is first formulated probabilistically to extract domain-invariant feature through multi-domain image translation. And then a novel gradient-weighted similarity activation mapping loss (Grad-SAM) is incorporated for finer localization with high accuracy. We also propose a new adaptive triplet loss to boost the contrastive learning of the embedding in a self-supervised manner. The final coarse-to-fine image retrieval pipeline is implemented as the sequential combination of models without and with Grad-SAM loss. Extensive experiments have been conducted to validate the effectiveness of the proposed approach on the CMU-Seasons dataset. The strong generalization ability of our approach is verified on RobotCar dataset using models pre-trained on urban part of CMU-Seasons dataset. Our performance is on par with or even outperforms the state-of-the-art image-based localization baselines in medium or high precision, especially under the challenging environments with illumination variance, vegetation and night-time images. The code and pretrained models are available on https://***/HanjiangHu/DISAM. Copyright © 2020, The Authors. All rights reserved.

关键词： Image retrieval

来源：评论

学校读者我要写书评

暂无评论

An Optimal Tracking control Method with Q-learning for Discrete-time Linear Switched system

An Optimal Tracking Control Method with Q-learning for Discr...

引用

第三十九届中国控制会议

作者： Shangwei Zhao Jingcheng Wang Hongyuan Wang Haotian Xu Automation Department Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China Autonomous Systems and Intelligent Control International Joint Research Center Xi'an Technological University

In this paper, a novel approach combining Q-learning method and two-stage optimization is proposed to solve linear quadratic tracking(LQT) problem for unknown discrete-time switched system. An augmented system consisting of switched subsystem and reference trajectory is built and Q-learning method is introduced to identify each subsystem without requiring any knowledge of augmented system state dynamics. Then, based on the optimal control laws for each subsystem obtained by Q-learning in advance, the optimal hybrid control law including switching mode and control input is obtained by the two-stage optimization framework. Furthermore, the optimality of the algorithm is proved. Finally, a simulation case is used to testify the effectiveness of the proposed algorithm.

关键词： Tracking control Linear switched system Q-learning

来源：评论

学校读者我要写书评

暂无评论

Photo-Based Monitoring of Particulate Matter in the Campus: A New Strategy for Student Health

Photo-Based Monitoring of Particulate Matter in the Campus: ...

引用

2020 International Conference on Green Energy, Environment and Sustainable Development, GEESD 2020

作者： Zhang, Yonghui Gu, Ke Xia, Zhifang Qiao, Junfei Faculty of Information Technology Beijing University of Technology Beijing100124 China Engineering Research Center of Intelligent Perception and Autonomous Control Ministry of Education Beijing100124 China Beijing Key Laboratory of Computational Intelligence and Intelligent System Beijing100124 China Beijing Artificial Intelligence Institute Beijing100124 China State Information Center Beijing100045 China

It is imperative for the students' future health to ensure the students in good physical levels. Recent years have witnessed the increasingly serious harm to student health caused by the continually growing concentration of Particulate Matters (PMs). Consequently, the task of preventing and controlling PM concentrations in the campus is eagerly required. A well-designed model for the monitoring of PM (as the basis for PM prevention and control) has posed a big challenge. Prior works have revealed that photo-based methods are available for the monitoring of PM. Towards validating the effectiveness of existing methods for PM monitoring in the campus, we construct a novel dataset that involves 1,500 photos collected in the Beijing University of Technology. Results confirm that stated-of-the-art methods are far from ideal for the monitoring of PM in the campus. To solve the aforesaid issue, this paper further proposes a novel photo-based PM monitoring model by using the weighted average method solved by LASSO regression to fuse the above methods' outputs tested to infer the PM values. Results demonstrate the superiority of our proposed model as compared to state-of-the-art methods on the large-scale AQPDBJUT dataset. © Published under licence by IOP Publishing Ltd.

关键词： Students

来源：评论

学校读者我要写书评

暂无评论

Algorithm of Identification for Water Parameters of Linear Water Waves

Algorithm of Identification for Water Parameters of Linear W...

引用

第32届中国控制与决策会议

作者： Yuying Jian Hailong Pei Chengzhong Xu Key Laboratory of Autonomous Systems and Networked Control Ministry of EducationUnmanned Aerial Vehicle Systems Engineering Technology Research Center of GuangdongSouth China University of Technology LAGEP Batiment CPEUniversity Claude Bernard-Lyon 1

In this paper,it is supposed that the linearized water wave equation(LWWE) can describe the movement of water *** the identification algorithm we put forward in this paper,the depth of water,the elevation of the wave surface,and the velocity potential can be calculated from the measured velocity of surface water waves at the same *** show the estimability by proving the mapping from the depth of water,the elevation of wave surface and the velocity potential to the measurement is ***,we verify our proposed algorithm,which is on the basis of the classical gradient descent method,with some numerical simulations.

关键词： system identification gradient descent method numerical simulations

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：