期刊文献+
共找到8,666篇文章
< 1 2 250 >
每页显示 20 50 100
Force Compensation Control for Electro-Hydraulic Servo System with Pump-Valve Compound Drive via QFT-DTOC
1
作者 Kaixian Ba Yuan Wang +4 位作者 Xiaolong He Chunyu Wang Bin Yu Yaliang Liu Xiangdong Kong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期228-246,共19页
Each joint of a hydraulic-driven legged robot adopts a highly integrated hydraulic drive unit(HDU),which features a high power-weight ratio.However,most HDUs are throttling-valve-controlled cylinder systems,which exhi... Each joint of a hydraulic-driven legged robot adopts a highly integrated hydraulic drive unit(HDU),which features a high power-weight ratio.However,most HDUs are throttling-valve-controlled cylinder systems,which exhibit high energy losses.By contrast,pump control systems offer a high efficiency.Nevertheless,their response ability is unsatisfactory.To fully utilize the advantages of pump and valve control systems,in this study,a new type of pump-valve compound drive system(PCDS)is designed,which can not only effectively reduce the energy loss,but can also ensure the response speed and response accuracy of the HDUs in robot joints to satisfy the performance requirements of robots.Herein,considering the force control requirements of energy conservation,high precision,and fast response of the robot joint HDU,a nonlinear mathematical model of the PCDS force control system is first introduced.In addition,pressure-flow nonlinearity,friction nonlinearity,load complexity and variability,and other factors affecting the system are considered,and a novel force control method based on quantitative feedback theory(QFT)and a disturbance torque observer(DTO)is designed,which is denoted as QFT-DTOC herein.This method improves the control accuracy and robustness of the force control system,reduces the effect of the disturbance torque on the control performance of the servo motor,and improves the overall force control performance of the system.Finally,experimental verification is performed using the PCDS performance test platform.The experimental results and quantitative data show that the QFT-DTOC proposed herein can significantly improve the force control performance of the PCDS.The relevant force control method can be used as a bottom-control method for the hydraulic servo system to provide a foundation for implementing the top-level trajectory planning of the robot. 展开更多
关键词 Legged robot Pump-valve compound drive system(PCDS) force compensation control Quantitative feedback theory(QFT) Disturbance torque observer(DTO)
下载PDF
A framework of force of information influence and application for C4KISR system
2
作者 MAO Shaojie DIAO Lianwang +6 位作者 SUN Yu WANG Heng YI Kan XU Xin MAO Xiaobin ZHANG Kecheng SHENG Long 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期430-443,共14页
The subversive nature of information war lies not only in the information itself, but also in the circulation and application of information. It has always been a challenge to quantitatively analyze the function and e... The subversive nature of information war lies not only in the information itself, but also in the circulation and application of information. It has always been a challenge to quantitatively analyze the function and effect of information flow through command, control, communications, computer, kill, intelligence,surveillance, reconnaissance (C4KISR) system. In this work, we propose a framework of force of information influence and the methods for calculating the force of information influence between C4KISR nodes of sensing, intelligence processing,decision making and fire attack. Specifically, the basic concept of force of information influence between nodes in C4KISR system is formally proposed and its mathematical definition is provided. Then, based on the information entropy theory, the model of force of information influence between C4KISR system nodes is constructed. Finally, the simulation experiments have been performed under an air defense and attack scenario. The experimental results show that, with the proposed force of information influence framework, we can effectively evaluate the contribution of information circulation through different C4KISR system nodes to the corresponding tasks. Our framework of force of information influence can also serve as an effective tool for the design and dynamic reconfiguration of C4KISR system architecture. 展开更多
关键词 information warfare command control communications computer KILL intelligence surveillance reconnaissance(C4KISR)system information circulation force of information influence information entropy
下载PDF
FUZZY COORDINATION AND FORCE/POSITION CONTROL OF ROBOTIC MANIPULATOR
3
作者 乔兵 尉忠信 朱剑英 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1999年第1期55-60,共6页
It is crucial for implementing force/position control of robotic manipulator under the constraint of unknown environment to determine the force control and the position control directions. This paper presents an on l... It is crucial for implementing force/position control of robotic manipulator under the constraint of unknown environment to determine the force control and the position control directions. This paper presents an on line algorithm to real timely estimate the tangent and the normal vectors of the constraint surface based on the measured contact force under the consideration of frictional force. A fuzzy synthesis policy is proposed to coordinate the conflict between the compliant force control and the stiff position control. An experimental study on an AdeptThree, a SCARA type robotic manipulator, is conducted. The experimental results show that the policy presented in the paper is effective. 展开更多
关键词 robotic manipulator force/position control CONSTRAINTS COORDINATION fuzzy synthesis
下载PDF
Impedance force control for position controlled robotic manipulators under the constraint of unknown environments
4
作者 乔兵 陆荣鑑 《Journal of Southeast University(English Edition)》 EI CAS 2003年第4期359-363,共5页
A force control strategy for position controlled robotic manipulators is presented. On line force feedback data are employed to estimate the local shape of the unknown constraint. The estimated vectors are used to ge... A force control strategy for position controlled robotic manipulators is presented. On line force feedback data are employed to estimate the local shape of the unknown constraint. The estimated vectors are used to generate the virtual reference trajectory for the target impedance model that is driven by the force error to produce command position. By following the command position trajectory the robotic manipulator can follow the unknown constraint surface while keeping an acceptable force error in a manner depicted by the target impedance model. Computer simulation on a 3 linked planar manipulator and experimental studies on an Adept 3, an SCARA type robotic manipulator, are conducted to verify the force tracking capability of the proposed control strategy. 展开更多
关键词 robotic manipulators force/position control unknown constraint
下载PDF
ForceControl组态软件及其在PLC实验中的应用 被引量:5
5
作者 孙晓雷 《芜湖职业技术学院学报》 2008年第4期59-61,共3页
利用力控组态软件开发PLC实验项目能丰富实验内容、模拟工业现场;达到理论联系实际的目的。用力控组态软件开发PLC仿真实验的过程,为PLC的实验教学提供了一条新的途径。
关键词 力控组态软件 工业控制 PLC 仿真实验
下载PDF
基于CAN和Force Control V7.0粮库数字化监控系统设计
6
作者 曹昌勇 《聊城大学学报(自然科学版)》 2013年第4期103-106,共4页
本文搭建了一种基于CAN总线和力控Force Control V7.0的粮库温湿度监控系统,实现现场温湿度监控.该系统由上位机和下位机两部分组成,采用分布式CAN总线网络结构.下位机主要完成现场数据的采集,通过CAN智能节点转换成CAN总线能接收的帧信... 本文搭建了一种基于CAN总线和力控Force Control V7.0的粮库温湿度监控系统,实现现场温湿度监控.该系统由上位机和下位机两部分组成,采用分布式CAN总线网络结构.下位机主要完成现场数据的采集,通过CAN智能节点转换成CAN总线能接收的帧信息.上位机主要是通过CAN接口卡接收实时采集的数据,对下位机进行实时监控.最后实验表明,该监控系统实时性好,可靠性高,具有较好的实际应用价值. 展开更多
关键词 CAN总线 数字式 force control
下载PDF
Composite Adaptive Control of Belt Polishing Force for Aero-engine Blade 被引量:12
7
作者 ZHsAO Pengbing SHI Yaoyao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第5期988-996,共9页
The existing methods for blade polishing mainly focus on robot polishing and manual grinding.Due to the difficulty in high-precision control of the polishing force,the blade surface precision is very low in robot poli... The existing methods for blade polishing mainly focus on robot polishing and manual grinding.Due to the difficulty in high-precision control of the polishing force,the blade surface precision is very low in robot polishing,in particular,quality of the inlet and exhaust edges can not satisfy the processing requirements.Manual grinding has low efficiency,high labor intensity and unstable processing quality,moreover,the polished surface is vulnerable to burn,and the surface precision and integrity are difficult to ensure.In order to further improve the profile accuracy and surface quality,a pneumatic flexible polishing force-exerting mechanism is designed and a dual-mode switching composite adaptive control(DSCAC) strategy is proposed,which combines Bang-Bang control and model reference adaptive control based on fuzzy neural network(MRACFNN) together.By the mode decision-making mechanism,Bang-Bang control is used to track the control command signal quickly when the actual polishing force is far away from the target value,and MRACFNN is utilized in smaller error ranges to improve the system robustness and control precision.Based on the mathematical model of the force-exerting mechanism,simulation analysis is implemented on DSCAC.Simulation results show that the output polishing force can better track the given signal.Finally,the blade polishing experiments are carried out on the designed polishing equipment.Experimental results show that DSCAC can effectively mitigate the influence of gas compressibility,valve dead-time effect,valve nonlinear flow,cylinder friction,measurement noise and other interference on the control precision of polishing force,which has high control precision,strong robustness,strong anti-interference ability and other advantages compared with MRACFNN.The proposed research achieves high-precision control of the polishing force,effectively improves the blade machining precision and surface consistency,and significantly reduces the surface roughness. 展开更多
关键词 BLADE polishing force Bang-Bang control fuzzy neural network model reference adaptive control
下载PDF
Improved hybrid position/force controller design of a flexible robot manipulator using a sliding observer 被引量:4
8
作者 Farooq M Wang Daobo Dar N. U 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第1期146-158,共13页
An improved hybrid position/force controller design of a flexible robot manipulator is presented using a sliding observer. The friction between the end effector and the environment is considered and compensated. For s... An improved hybrid position/force controller design of a flexible robot manipulator is presented using a sliding observer. The friction between the end effector and the environment is considered and compensated. For systematic reasons the controller is designed taking into consideration the rigid link subsystems and the flexible joints. The proposed control system satisfies the stability of the two subsystems and copes with the uncertainty of robot dynamics. A sliding observer is designed to estimate the time derivative of the torque applied as input to the rigid part of the robot. For the stability of the observer, it is assumed that the uncertainty of the observed system is bounded. A MRAC algorithm is used for the estimation of the friction forces at the contact point between the end effector and the environment. Finally simulation and experimental results are given, to demonstrate the effectiveness of the proposed controller. 展开更多
关键词 force control sliding control Lyapunov stability robot end effector friction force.
下载PDF
Optimal Design and Force Control of a Nine-Cable-Driven Parallel Mechanism for Lunar Takeoff Simulation 被引量:5
9
作者 Wangmin Yi Yu Zheng +3 位作者 Weifang Wang XiaoqiangTang Xinjun Liu Fanwei Meng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第4期35-46,共12页
Traditional simulation methods are unable to meet the requirements of lunar takeo simulations, such as high force output precision, low cost, and repeated use. Considering that cable-driven parallel mechanisms have th... Traditional simulation methods are unable to meet the requirements of lunar takeo simulations, such as high force output precision, low cost, and repeated use. Considering that cable-driven parallel mechanisms have the advantages of high payload to weight ratio, potentially large workspace, and high-speed motion, these mechanisms have the potential to be used for lunar takeo simulations. Thus, this paper presents a parallel mechanism driven by nine cables. The purpose of this study is to optimize the dimensions of the cable-driven parallel mechanism to meet dynamic workspace requirements under cable tension constraints. The dynamic workspace requirements are derived from the kinematical function requests of the lunar takeo simulation equipment. Experimental design and response surface methods are adopted for building the surrogate mathematical model linking the optimal variables and the optimization indices. A set of dimensional parameters are determined by analyzing the surrogate mathematical model. The volume of the dynamic workspace increased by 46% after optimization. Besides, a force control method is proposed for calculating output vector and sinusoidal forces. A force control loop is introduced into the traditional position control loop to adjust the cable force precisely, while controlling the cable length. The e ectiveness of the proposed control method is verified through experiments. A 5% vector output accuracy and 12 Hz undulation force output can be realized. This paper proposes a cable-driven parallel mechanism which can be used for lunar takeo simulation. 展开更多
关键词 force control Lunar takeo simulation Parallel robots Surrogate mathematical model
下载PDF
Application of μ Theory in Compliant Force Control 被引量:4
10
作者 张尚盈 韩俊伟 +1 位作者 赵慧 黄其涛 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第1期89-96,共8页
The application of μ theory in compliant force control system is studied. A compliant force control strategy is developed based on the inner loop position control of 6-DOF parallel robot in order to simulate the push... The application of μ theory in compliant force control system is studied. A compliant force control strategy is developed based on the inner loop position control of 6-DOF parallel robot in order to simulate the push and pull process of forcible alignment in space docking, Considering uncertainties such as parameter perturbations, model perturbations and external disturbances, etc., a robust force controller is designed using μ synthesis theory. The robust stability and robust performance are compared by analysis between the designed robust force controller and the classical force controller. The experiment results of the designed robust force controller and the classical force controller are shown. The results indicate that the designed robust force controller is of efficiency and superiority. 展开更多
关键词 parallel robot μ synthesis μ analysis compliant force control UNCERTAINTY ROBUST
下载PDF
Trajectory Tracking of a Planer Parallel Manipulator by Using Computed Force Control Method 被引量:6
11
作者 Atilla BAYRAM 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第2期449-458,共10页
Despite small workspace, parallel manipulators have some advantages over their serial counterparts in terms of higher speed, acceleration, rigidity, accuracy, manufacturing cost and payload. Accordingly, this type of ... Despite small workspace, parallel manipulators have some advantages over their serial counterparts in terms of higher speed, acceleration, rigidity, accuracy, manufacturing cost and payload. Accordingly, this type of manipulators can be used in many applications such as in high-speed machine tools, tuning machine for feeding, sensitive cutting, assembly and packaging. This paper presents a special type of planar parallel manipulator with three degrees of freedom. It is constructed as a variable geometry truss generally known planar Stewart platform. The reachable and orientation workspaces are obtained for this manipulator. The inverse kinematic analysis is solved for the trajectory tracking according to the redundancy and joint limit avoidance. Then, the dynamics model of the manipulator is established by using Virtual Work method. The simulations are performed to follow the given planar trajectories by using the dynamic equations of the variable geometry truss manipulator and computed force control method. In computed force control method, the feedback gain matrices for PD control are tuned with fixed matrices by trail end error and variable ones by means of optimization with genetic algorithm. 展开更多
关键词 Parallel manipulator Variable geometry truss manipulator Planar Stewart platform. Dynamic analysis Computed force control Genetic algorithm
下载PDF
Parameters Sensitivity Characteristics of Highly Integrated Valve-Controlled Cylinder Force Control System 被引量:8
12
作者 Kai-Xian Ba Bin Yu +4 位作者 Xiang-Dong Kong Chun-He Li Qi-Xin Zhu Hua-Long Zhao Ling-Jian Kong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第2期159-175,共17页
Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system s... Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance. 展开更多
关键词 Highly integrated valve?controlled cylinder system force control system Matrix sensitivity analysis Orthogonal test design Sensitivity index
下载PDF
A novel grasping force control strategy for multi-fingered prosthetic hand 被引量:4
13
作者 张庭 姜力 刘宏 《Journal of Central South University》 SCIE EI CAS 2012年第6期1537-1542,共6页
A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are use... A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are used in free and constraint spaces, respectively. The fuzzy observer is adopted in transition in order to switch control mode. Two control modes use one position-based impedance controller. In order to achieve grasping force track, reference force is added to the impedance controller in the constraint space. Trajectory tracking in free space and torque tracking in constrained space are realized, and reliability of mode switch and stability of system are achieved. An adaptive sliding mode friction compensation method is proposed. This method makes use of terminal sliding mode idea to design sliding mode function, which makes the tracking error converge to zero in finite time and avoids the problem of conventional sliding surface that tracking error cannot converge to zero. Based on the characteristic of the exponential form friction, the sliding mode control law including the estimation of friction parameter is obtained through terminal sliding mode idea, and the online parameter update laws are obtained based on Lyapunov stability theorem. The experiments on the HIT Prosthetic Hand IV are carried out to evaluate the grasping force control strategy, and the experiment results verify the effectiveness of this control strategy. 展开更多
关键词 GRASPING impedance control force control sliding mode control prosthetic hand
下载PDF
Adaptive robust output force tracking control of pneumatic cylinder while maximizing/minimizing its stiffness 被引量:4
14
作者 孟德远 陶国良 +1 位作者 班伟 钱鹏飞 《Journal of Central South University》 SCIE EI CAS 2013年第6期1510-1518,共9页
The system considered in this work consists of a cylinder which is controlled by a pair of three-way servo valves rather than a four-way one.Therefore,the cylinder output stiffness is independently controllable of the... The system considered in this work consists of a cylinder which is controlled by a pair of three-way servo valves rather than a four-way one.Therefore,the cylinder output stiffness is independently controllable of the output force.A discontinuous projection based adaptive robust controller (ARC) was constructed to achieve high-accuracy output force trajectory tracking for the system.In ARC,on-line parameter adaptation method was adopted to reduce the extent of parametric uncertainties due to the variation of friction parameters,and sliding mode control method was utilized to attenuate the effects of parameter estimation errors,unmodelled dynamics and disturbance.Furthermore,output stiffness maximization/minimization was introduced to fulfill the requirement of many robotic applications.Extensive experimental results were presented to illustrate the effectiveness and the achievable performance of the proposed scheme.For tracking a 0.5 Hz sinusoidal trajectory,maximum tracking error is 4.1 N and average tracking error is 2.2 N.Meanwhile,the output stiffness can be made and maintained near its maximum/minimum. 展开更多
关键词 servo-pneumatic systems output force control cylinder output stiffness sliding mode control adaptive control
下载PDF
Application and Analysis of Force Control Strategies to Deburring and Grinding 被引量:14
15
作者 Frank Domroes Carsten Krewet Bernd Kuhlenkoetter 《Modern Mechanical Engineering》 2013年第2期11-18,共8页
This paper aims to give an insight into the development and evaluation of force controlled machining processes with a commercially available setup. We will focus on a deburring and a grinding scenario, representing th... This paper aims to give an insight into the development and evaluation of force controlled machining processes with a commercially available setup. We will focus on a deburring and a grinding scenario, representing the major applications in today’s robot machining. Whereas the deburring use-case implements a force dependent feed-rate control, the grinding use-case implements an orthogonal force (pressure) control. Both strategies will be evaluated and the influence of general machining and robot specific parameters will be discussed. 展开更多
关键词 ROBOT MACHINING DEBURRING GRINDING force control STRATEGIES
下载PDF
Decentralized adaptive neural network sliding mode position/force control of constrained reconfigurable manipulators 被引量:2
16
作者 李元春 丁贵彬 赵博 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第11期2917-2925,共9页
A decentralized adaptive neural network sliding mode position/force control scheme is proposed for constrained reconfigurable manipulators. Different from the decentralized control strategy in multi-manipulator cooper... A decentralized adaptive neural network sliding mode position/force control scheme is proposed for constrained reconfigurable manipulators. Different from the decentralized control strategy in multi-manipulator cooperation, the proposed decentralized position/force control scheme can be applied to series constrained reconfigurable manipulators. By multiplying each row of Jacobian matrix in the dynamics by contact force vector, the converted joint torque is obtained. Furthermore, using desired information of other joints instead of their actual values, the dynamics can be represented as a set of interconnected subsystems by model decomposition technique. An adaptive neural network controller is introduced to approximate the unknown dynamics of subsystem. The interconnection and the whole error term are removed by employing an adaptive sliding mode term. And then, the Lyapunov stability theory guarantees the stability of the closed-loop system. Finally, two reconfigurable manipulators with different configurations are employed to show the effectiveness of the proposed decentralized position/force control scheme. 展开更多
关键词 constrained reconfigurable manipulators position/force control model decomposition decentralized control neural network
下载PDF
Force Control Compensation Method with Variable Load Stiffness and Damping of the Hydraulic Drive Unit Force Control System 被引量:10
17
作者 KONG Xiangdong BA Kaixian +3 位作者 YU Bin CAO Yuan ZHU Qixin ZHAO Hualong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第3期454-464,共11页
Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit(HDU), and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force... Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit(HDU), and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force control inevitably. In the recent years, although many scholars researched some control methods such as disturbance rejection control, parameter self-adaptive control, impedance control and so on, to improve the force control performance of HDU, the robustness of the force control still needs improving. Therefore, how to simulate the complex and variable load characteristics of the environment structure and how to ensure HDU having excellent force control performance with the complex and variable load characteristics are key issues to be solved in this paper. The force control system mathematic model of HDU is established by the mechanism modeling method, and the theoretical models of a novel force control compensation method and a load characteristics simulation method under different environment structures are derived, considering the dynamic characteristics of the load stiffness and the load damping under different environment structures. Then, simulation effects of the variable load stiffness and load damping under the step and sinusoidal load force are analyzed experimentally on the HDU force control performance test platform, which provides the foundation for the force control compensation experiment research. In addition, the optimized PID control parameters are designed to make the HDU have better force control performance with suitable load stiffness and load damping, under which the force control compensation method is introduced, and the robustness of the force control system with several constant load characteristics and the variable load characteristics respectively are comparatively analyzed by experiment. The research results indicate that if the load characteristics are known, the force control compensation method presented in this paper has positive compensation effects on the load characteristics variation, i.e., this method decreases the effects of the load characteristics variation on the force control performance and enhances the force control system robustness with the constant PID parameters, thereby, the online PID parameters tuning control method which is complex needs not be adopted. All the above research provides theoretical and experimental foundation for the force control method of the quadruped robot joints with high robustness. 展开更多
关键词 quadruped robot force control system hydraulic drive unit force control compensation method variable load stiffness and damping simulation
下载PDF
Nonlinear control techniques for an atomic force microscope system 被引量:2
18
作者 YongchunFANG MatthewFEEMSTER +1 位作者 DarrenDAWSON NaderM.JALILI 《控制理论与应用(英文版)》 EI 2005年第1期85-92,共8页
Two nonlinear control techniques are proposed for an atomic force microscopesystem. Initially, a learning-based control algorithm is developed for the microcantilever-samplesystem that achieves asymptotic cantilever t... Two nonlinear control techniques are proposed for an atomic force microscopesystem. Initially, a learning-based control algorithm is developed for the microcantilever-samplesystem that achieves asymptotic cantilever tip tracking for periodic trajectories. Specifically, thecontrol approach utilizes a learning-based feedforward term to compensate for periodic dynamics andhigh-gain terms to account for non-periodic dynamics. An adaptive control algorithm is thendeveloped to achieve asymptotic cantilever tip tracking for bounded tip trajectories despiteuncertainty throughout the system parameters. Simulation results are provided to illustrate theefficacy and performance of the control strategies. 展开更多
关键词 atomic force microscope adaptive control learning control lyapunov-basedstability analysis
下载PDF
Mechanism of controlling turbulent channel flow with the effect of spanwise Lorentz force distribution 被引量:2
19
作者 韩洋 张辉 +3 位作者 范宝春 李健 江代文 赵子杰 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期250-258,共9页
A direct numerical simulation(DNS) is performed to investigate the control effect and mechanism of turbulent channel flow with the distribution of spanwise Lorentz force. A sinusoidal distribution of constant spanwi... A direct numerical simulation(DNS) is performed to investigate the control effect and mechanism of turbulent channel flow with the distribution of spanwise Lorentz force. A sinusoidal distribution of constant spanwise Lorentz force is selected, of which the control effects, such as flow characters, mean Reynolds stress, and drag reductions, at different parameters of amplitude A and wave number k_x are discussed. The results indicate that the control effects vary with the parameter A and k_x. With the increase of A, the drag reduction rate D_r first increases and then decreases rapidly at low k_x,and slowly at high k_x. The low drag reduction(or even drag increase) is due to a weak suppression or even the enhancements of the random velocity fluctuation and mean Reynolds stress. The efficient drag reduction is due to the quasi-streamwise vortex structure induced by Lorentz force, which contributes to suppressing the random velocity fluctuation and mean Reynolds stress, and the negative vorticity improves the distribution of streamwise velocity. Therefore, the optimal control effect with a drag reduction of up to 58% can be obtained. 展开更多
关键词 flow control turbulent channel flow Lorentz force direct numerical simulation
下载PDF
Learning-based force servoing control of a robot with vision in an unknown environment 被引量:2
20
作者 XiaoNanfeng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2004年第2期171-178,共8页
A learning-based control approach is presented for force servoing of a robot with vision in an unknown environment. Firstly, mapping relationships between image features of the servoing object and the joint angles of ... A learning-based control approach is presented for force servoing of a robot with vision in an unknown environment. Firstly, mapping relationships between image features of the servoing object and the joint angles of the robot are derived and learned by a neural network. Secondly, a learning controller based on the neural network is designed for the robot to trace the object. Thirdly, a discrete time impedance control law is obtained for the force servoing of the robot, the on-line learning algorithms for three neural networks are developed to adjust the impedance parameters of the robot in the unknown environment. Lastly, wiping experiments are carried out by using a 6 DOF industrial robot with a CCD camera and a force/torque sensor in its end effector, and the experimental results confirm the effecti veness of the approach. 展开更多
关键词 ROBOTICS force servoing vision control learning algorithm neural network.
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部