检索结果-南通市图书馆

A fast scanning strategy based on trajectory shaping for atomic force microscopy

Nano Research 2022年第7期15卷 6438-6446页

作者： Yinan Wu Yingao Chang Yongchun Fang Zhi Fan Institute of Robotics and Automatic Information System College of Artificial IntelligenceNankai UniversityTianjin 300350China Tianjin Key Laboratory of Intelligent Robotics Nankai UniversityTianjin 300350China

To improve the scanning speed of an atomic force microscopy(AFM),a smooth scanning pattern is elaborately devised via trajectory shaping in this paper,so as to achieve fast imaging without hardware modification.Specifically,in the proposed scanning method,the piezoelectric actuator tracks a well-designed smooth periodic signal in x-direction,and simultaneously tracks a step signal in y-direction.The advantage of the proposed method is that it does not require additional data reprocessing to construct the morphology of the sample surface,while significantly increasing the scanning bandwidth restricted by the raster scanning method.Particularly,to directly utilize the height data collected by scanning to produce the sample morphology,the forward process in the common raster scanning mode is retained in the proposed method,the tracking signal in the forward process is thus set to a ramp function in x-direction.In addition,to ensure the continuity and smoothness of the entire tracking signal in x-direction,a segment of a sine curve is uniquely determined as the backward tracking signal by position and acceleration constraints,so as to ensure that the forward and backward curves are continuous and acceleration-continuous at the intersection point.Moreover,the frequency spectrum analysis of the designed smooth signal is carried out to exhibit the depressed amplitudes of high-frequency components,which demonstrates that the proposed method is able to reduce the resonance in AFM high-speed scanning,so as to improve the capacity of rapidly generating high-quality images.Finally,convincing comparison experiments are implemented to verify the imaging performance of the designed scanning algorithm.

关键词： atomic force microscopy fast scanning smooth signal trajectory shaping

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Adaptive tracking control of flapping wing micro-air vehicles with averaging theory

引用

CAAI Transactions on Intelligence Technology 2018年第1期3卷 18-27页

作者： Chen Qian Yongchun Fang Institute of Robotics and Automatic Information Systems College of Computer and Control Engineering Tianjin 300353People's Republic of China Tianjin Key Laboratory of Intelligent Robotics Nankai University Tianjin 300353 People's Republic of China

An input constrained adaptive tracking controller is designed for flapping micro aerial vehicles, wherein the moving averaging filter is adopted to estimate the averaged states of the system. Specifically, in the outer loop controller, an observer is constructed to estimate the disturbances within the system. Moreover, the constrained thrust is designed to keep the frequency in a proper region so as to meet the requirement of average estimation. Then, a tracking differentiator is used to provide trackable trajectories for the inner loop. Subsequently, a new quaternion-based hybrid attitude tracking controller is designed which successfully deals with high-frequency noises and avoids possible chattering. As supported by mathematical analysis, the proposed control strategy guarantees the uniform ultimate boundedness of the closed-loop system, and it keeps the control torques within the permitted range to meet the application requirement. At last, numerical simulations are carried out to support the validity of the proposed controller, whose results are satisfactory even when the thrust and torques are saturated.

关键词：飞行器跟踪器人工智能发展现状

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A novel frequency-dependent hysteresis model based on improved neural Turing machine

引用

Science China(Information Sciences) 2023年第1期66卷 330-331页

作者： Yinan WU Yongchun Fang Zhi FAN Cunhuan LIU Institute of Robotics and Automatic Information System College of Artificial IntelligenceNankai University Tianjin Key Laboratory of Intelligent Robotics Nankai University

Dear editor,The inherent hysteresis of a piezoelectric actuator(PEA) results in intricate nonlinearity between the output displacement and input voltage, which restricts positioning accuracy of the actuator [1, 2]. Hysteresis behavior appears as a coupling of nonlinearity, frequency-dependence and memory characteristic, which makes it difficult to comprehensively characterize hysteresis [3]. To eliminate the effect of hysteresis on the positioning accuracy of PEAs,

关键词： ATOMIC-FORCE MICROSCOPY

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Swing Suppression and Accurate Positioning Control for Underactuated Offshore Crane Systems Suffering From Disturbances

引用

IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 892-900页

作者： Tong Yang Ning Sun He Chen Yongchun Fang Institute of Robotics and Automatic Information Systems(IRAIS) College of Artificial IntelligenceTianjin 300350China Tianjin Key Laboratory of Intelligent Robotics(tjKLIR) Nankai UniversityTianjin 300350China IEEE School of Artificial Intelligence Hebei University of TechnologyTianjin 300401China

Offshore cranes are widely applied to transfer largescale cargoes and it is challenging to develop effective control for them with sea wave disturbances. However, most existing controllers can only yield ultimate uniform boundedness or asymptotical stability results for the system's equilibrium point, and the state variables' convergence time cannot be theoretically guaranteed. To address these problems, a nonlinear sliding mode-based controller is suggested to accurately drive the boom/rope to their desired positions. Simultaneously, payload swing can be eliminated rapidly with sea waves. As we know, this paper firstly presents a controller by introducing error-related bounded functions into a sliding surface, which can realize boom/rope positioning within a finite time, and both controller design and analysis based on the nonlinear dynamics are implemented without any linearization manipulations. Moreover, the stability analysis is theoretically ensured with the Lyapunov method. Finally, we employ some experiments to validate the effectiveness of the proposed controller.

关键词： Boom/rope positioning offshore cranes swing elimination underactuated systems

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adaptive Sliding-Mode Disturbance Observer-Based Nonlinear Control for Unmanned Dual-Arm Aerial Manipulator Subject to State Constraints

引用

Guidance, Navigation and Control 2023年第3期3卷 47-64页

作者： Bingbing Liu Hai Yu Shizhen Wu Xiao Liang Yongchun Fang College of Artificial Intelligence Nankai University Tianjin 300350P.R.China

The unmanned dual-arm aerial manipulator system is composed of a multirotor unmanned aerial vehicle(UAV)and two manipulators.Compared to a single manipulator,dual-arm always provides greater°exibility and versatility in both goods delivery and complex task execution.However,the practical application of the system is limited due to nonlinearities and complex dynamic coupling behavior between the multirotor and the manipulator,as well as the one between the inner and outer loop of the multirotor.In this paper,a holistic model of the dual-arm aerial manipulator system is¯rst derived with complete model information.Subsequently,an adaptive sliding-mode disturbance observer(ASMDO)is proposed to handle external disturbances and unmeasurable disturbances caught by unmeasurable angular velocity and acceleration of the manipulators.Moreover,for safety concerns and transient performance requirements,the state constraints should be guaranteed.To this end,an auxiliary term composed of constrained variable signals is introduced.Then,the performance of the designed method is proven by rigorous analysis.Finally,the proposed method is validated through two sets of simulation tests.

关键词： Unmanned dual-arm aerial manipulator adaptive sliding-mode disturbance observer state constraint

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Trajectory planning-based control of underactuated wheeled inverted pendulum robots

引用

Science China(Information Sciences) 2019年第5期62卷 23-25页

作者： Dingkun LIANG Ning SUN Yiming WU Yongchun Fang Institute of Robotics and Automatic Information Systems (IRAIS) Tianjin Key Laboratory of Intelligent Robotics (tj KLIR) Nankai University

Dear editor,In modern industries, underactuated mechanical systems play an important role in various fields [1–6]. The wheeled inverted pendulum robot(WIPR) is a special type of non-linear and underactuated systems with strong state coupling.Typically, such a robot comprises two actuated wheels and three to-be-controlled state variables,

关键词： Trajectory planning-based control of underactuated wheeled inverted pendulum robots Figure

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural network-based adaptive sliding mode control for underactuated dual overhead cranes suffering from matched and unmatched disturbances

引用

Autonomous Intelligent Systems 2022年第1期2卷 1-15页

作者： Tianci Wen Yongchun Fang Biao Lu Institute of Robotics and Automatic Information System College of Artificial IntelligenceNankai UniversityTianjin300353China

To improve transportation capacity,dual overhead crane systems(DOCSs)are playing an increasingly important role in the transportation of large/heavy cargos and containers.Unfortunately,when trying to deal with the control problem,current methods fail to fully consider such factors as external disturbances,input dead zones,parameter uncertainties,and other unmodeled dynamics that DOCSs usually suffer from.As a result,dramatic degradation is caused in the control performance,which badly hinders the practical applications of DOCSs.Motivated by this fact,this paper designs a neural network-based adaptive sliding mode control(SMC)method for DOCS to solve the aforementioned issues,which achieves satisfactory control performance for both actuated and underactuated state variables,even in the presence of matched and mismatched disturbances.The asymptotic stability of the desired equilibrium point is proved with rigorous Lyapunov-based analysis.Finally,extensive hardware experimental results are collected to verify the efficiency and robustness of the proposed method.

关键词： Asymptotic stability Sliding mode control Neural networks Unmatched disturbances Underactuated system

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Control System Design for an Unmanned Helicopter to Track a Ground Target

引用

Chinese Journal of Mechanical Engineering 2011年第3期24卷 420-427页

作者： XIN Zhekui fang yongchun Beijing Aerospace Automatic Control Institute Beijing 100854 China Institute of Robotics andInformation Automatic System Nankai University Tianjin 300071 China

Due to potential wide applications,the problem of utilizing an unmanned helicopter to track a ground target has become one of the most active research directions in related areas.However,in most cases,it is possible for a dynamic target to implement evasive actions with strong maneuverability,such as a sudden turn during high-speed movement,to flee from the tracker,which then brings much difficulty for the design of tracking control systems.Currently,most research on this field focuses on utilizing a ground mobile robot to track a high-speed target.Unfortunately,it is very difficult to extend those developed methods to airborne applications due to much more complex dynamices of UAV-target relative motion.This study investiages thoroughly for the problem of using an unmanned helicopter to track a ground target,with particular emphasis on the avoidance of tracking failure caused by the evasive maneuvers of dynamic targets.Specifically,a novel control scheme,which consists of an innovative target tracking controller and a classical flight controller,is proposed for the helicopter-target tracking problem.Wherein,the tracking controller,whose design is the focus of the paper,aims to utilize the motion information of the helicopter and the dynamic target to construct a suitable trajectory for the helicopter,so that when it flies along this trajectory,the relative pose between the helicopter and the dynamic target will be kept consant.When designing the target tracking controller,a novel coordinate transformation is firstly introduced to convert the tracking system into a more compact form convenient for control law design,the desired velocities for the helicopter is then proposed with consideration of the dynamic constraint.The stability of the closed-loop system is finally analyzed by Lyapunov techniques.Based on Matlab/Simulink environment,two groups of simulation are conducted for the helicopter-target tracking control system where the target moves along a linear path and takes a sudden turn during high-speed moveme

关键词： unmanned helicopter trajectory plan target tracking

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sensorless Image Based Positioning Control Strategy Design for AFM Systems

Sensorless Image Based Positioning Control Strategy Design f...

引用

第36届中国控制会议

作者： LU Han fang yongchun Institute of Robotics and Automatic Information System Nankai University Tianjin Key Laboratory of Intelligent Robotics Nankai University

ISBN: (纸本)9781538629185

As a typical tool for micro/nano imaging and manipulations,an atomic force microscope（AFM） has been widely used in a variety of areas including biology,materials,chemistry,physics,and so on.Specifically,to accurately implement nanomanipulation tasks for an AFM system,it is essential to design a high-precision positioning control strategy with nanometer precision.However,unfortunately,owing to the drawbacks of piezo-hysteresis,cross-coupling of piezoelectric and other nonlinear characteristics of this system,the positioning control of the probe for an AFM-based nanomanipulation system is still a challenging problem.Moreover,in most cases,a displacement sensor,which can detect position signals in real time,is hard to be applied into an AFM system directly,which leads to much more limitations in designing an efficient positioning method.To tackle these problems,in this paper,an image based high-precision positioning control strategy for AFM systems is first proposed,which presents high-precision probe positioning without using any displacement sensors,and instead,the scanned image is the only feedback information we used.In particular,firstly a constant velocity spiral scanning pattern as well as a Gaussian functionbased distortion compensation model are proposed to obtain an undistorted image.Subsequently,a spiral trajectory planning based coarse positioning method is adopted to ensure a smooth and robust positioning process for most general samples.Then,considering some regular structure samples like particles,an improved local line scanning based method is proposed to further ensure more accurate positioning performance.Finally,some simulation results are presented to demonstrate the performance of the whole proposed positioning control strategy.

关键词： Atomic Force Microscope（AFM） Sensorless Positioning Control Strategy Image Based Positioning Control Distortion Compensation Model Spiral Trajectory Planning

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

招生-培养-毕业-就业一体化的全链条博士生培养模式

引用

学位与研究生教育 2022年第5期 24-29页

作者：方勇纯南开大学人工智能学院南开大学研究生院天津300350

面向博士生培养的“供给侧”改革,提出了以出口为牵引,招生–培养–毕业–就业一体化的全链条育人模式,具体包括招生环节的从严把关和师生相互适应;培养阶段从多个角度全面锻炼博士生的思维创新能力,并不断提升其综合素质;而毕业阶段则... 详细信息

面向博士生培养的“供给侧”改革,提出了以出口为牵引,招生–培养–毕业–就业一体化的全链条育人模式,具体包括招生环节的从严把关和师生相互适应;培养阶段从多个角度全面锻炼博士生的思维创新能力,并不断提升其综合素质;而毕业阶段则重点指导博士生为下一阶段做好充分准备,并提早规划以更好地应对在工作岗位上可能面临的困难。多年的实践经验表明:招生–培养–毕业–就业一体化全链条育人模式可以很好地确保博士生的培养质量。

关键词：供给侧改革招生–培养–毕业–就业一体化全链条育人四有好导师

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：