期刊文献+
共找到9,909篇文章
< 1 2 250 >
每页显示 20 50 100
Modified Two-Degrees-of-Freedom Internal Model Control for Non-Square Systems with Multiple Time Delays 被引量:25
1
作者 Jian-Chang Liu Nan Chen Xia Yu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第2期122-128,共7页
A modified two-degrees-of-freedom( M-TDOF) internal model control( IMC) method is proposed for non-square systems with multiple time delays and right-half-plane( RHP) zeros. In this method,pseudo-inverse is introduced... A modified two-degrees-of-freedom( M-TDOF) internal model control( IMC) method is proposed for non-square systems with multiple time delays and right-half-plane( RHP) zeros. In this method,pseudo-inverse is introduced to design the internal model controller,and a desired closed-loop transfer function is designed to eliminate the unrealizable factors of the derived controller. In addition,set-point tracking and load-disturbance rejection of each process are separately controlled by two controllers. The simulation results show that in addition to high decoupling performance and robustness,the proposed control method also effectively improves loaddisturbance rejection and simultaneously optimizes the input tracking performance and disturbance rejection performance by selecting the parameters of controllers. Furthermore,the higher tolerance of model mismatch is achieved in this paper. 展开更多
关键词 non-square system two degrees of freedom internal model control
下载PDF
Triad-displaced ULAs configuration for non-circular sources with larger continuous virtual aperture and enhanced degrees of freedom
2
作者 SHAIKH Abdul Hayee DANG Xiaoyu HUANG Daqing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期81-93,共13页
Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteris... Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteristics play a significant role in improving the direction-of-arrival(DOA)estimation accuracy.However,most of the existing NULA geometries are primarily applicable to circular sources(CSs),while they limitedly improve the DOF and continuous virtual aperture for noncircular sources(NCSs).Toward this purpose,we present a triaddisplaced ULAs(Tdis-ULAs)configuration for NCS.The TdisULAs structure generally consists of three ULAs,which are appropriately placed.The proposed antenna array approach fully exploits the non-circular characteristics of the sources.Given the same number of elements,the Tdis-ULAs design achieves more DOF and larger hole-free co-array aperture than its sparse array competitors.Advantageously,the number of uniform DOF,optimal distribution of elements among the ULAs,and precise element positions are uniquely determined by the closed-form expressions.Moreover,the proposed array also produces a filled resulting co-array.Numerical simulations are conducted to show the performance advantages of the proposed Tdis-ULAs configuration over its counterpart designs. 展开更多
关键词 direction-of-arrival(DOA)estimation sparse array non-circular source(NCS) sum co-array difference co-array degrees of freedom(Dof)
下载PDF
Type Synthesis of Two-Degrees-of-Freedom Rotational Parallel Mechanism with Two Continuous Rotational Axes 被引量:19
3
作者 XU Yundou ZHANG Dongsheng +2 位作者 WANG Min YAO Jiantao ZHAO Yongsheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期694-702,共9页
The two-rotational-degrees-of-freedom(2R) parallel mechanism(PM) with two continuous rotational axes(CRAs) has a simple kinematic model.It is therefore easy to implement trajectory planning,parameter calibration... The two-rotational-degrees-of-freedom(2R) parallel mechanism(PM) with two continuous rotational axes(CRAs) has a simple kinematic model.It is therefore easy to implement trajectory planning,parameter calibration,and motion control,which allows for a variety of application prospects.However,no systematic analysis on structural constraints of the 2R-PM with two CRAs has been performed,and there are only a few types of 2R-PM with two CRAs.Thus,a theory regarding the type synthesis of the 2R-PM with two CRAs is systematically established.First,combining the theories of reciprocal screw and space geometry,the spatial arrangement relationships of the constraint forces applied to the moving platform by the branches are explored,which give the 2R-PM two CRAs.The different distributions of the constraint forces in each branch are also studied.On the basis of the obtained structural constraints of branches,and considering the geometric relationships of constraint forces in each branch,the appropriate kinematic chains are constructed.Through the reasonable configuration of branch kinematic chains corresponding to every structural constraint,a series of new 2R-PMs with two CRAs are finally obtained. 展开更多
关键词 type synthesis continuous rotational axes two rotational degrees of freedom parallel mechanism constraint force
下载PDF
Behavior of Vortex-Induced Vibration of A Circular Cylinder Near A Deformable Wall with Two Degrees of Freedom in Steady Flow 被引量:1
4
作者 杨兵 马建林 +1 位作者 崔金声 徐万海 《China Ocean Engineering》 SCIE EI 2011年第4期549-564,共16页
The behavior of vortex-induced vibration of a two-degree-of-freedom cylinder near a deformable wall in steady flow is investigated experimentally. The typical phenomenon of the two-degree-of-freedom cylinder's VIV is... The behavior of vortex-induced vibration of a two-degree-of-freedom cylinder near a deformable wall in steady flow is investigated experimentally. The typical phenomenon of the two-degree-of-freedom cylinder's VIV is discussed. The influences of initial gap between the cylinder and the wall on the dynamic responses of the cylinder are analyzed. The comparison is made about dynamic responses of the cylinder with one and two degrees of freedom. Experimental results show that the vibration of the cylinder near a deformable wall with a small value of initial gap-to-diameter ratios can generally be divided into two phases. The initial gap-to-diameter ratios have a noticeable influence on the occurrence of transverse vibration. The transverse maximum amplitude of the cylinder with two degrees of freedom is larger than that of the cylinder with one degree of freedom under the condition with the same values of other parameters. However, the vibration frequency of the cylinder for the two degrees of freedom case is smaller than that for the one degree of freedom case at the same value of Vr number 展开更多
关键词 vortex-induced vibration two degrees of freedom deformable wall circular cylinder steady flow
下载PDF
Asymptotic dynamics of the alternate degrees of freedom for a two-mode system:An analytically solvable model
5
作者 M.Arsenijevi J.Jekni-Dugi M.Dugi 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期71-75,共5页
The composite systems can be non-uniquely decomposed into parts(subsystems).Not all decompositions(structures) of a composite system are equally physically relevant.In this paper we answer on theoretical ground wh... The composite systems can be non-uniquely decomposed into parts(subsystems).Not all decompositions(structures) of a composite system are equally physically relevant.In this paper we answer on theoretical ground why it may be so.We consider a pair of mutually un-coupled modes in the phase space representation that are subjected to the independent quantum amplitude damping channels.By investigating asymptotic dynamics of the degrees of freedom,we find that the environment is responsible for the structures non-equivalence.Only one structure is distinguished by both locality of the environmental influence on its subsystems and a classical-like description. 展开更多
关键词 amplitude dissipative channel two-mode state Kraus representation alternate degrees of freedom
下载PDF
HAMILTONIANS WITH TWO DEGREES OF FREEDOM ADMITTING A SINGLEVALUED GENERAL SOLUTION
6
作者 R.Conte M.Musette C.Verhoeven 《Analysis in Theory and Applications》 2005年第2期188-200,共13页
Following the basic principles stated by Painlevé, we first revisit the process of selecting the admissible time-independent Hamiltonians H = (p1^2 + p2^2)/2 + V(q1, q2) whose some integer power qj^nj (t)... Following the basic principles stated by Painlevé, we first revisit the process of selecting the admissible time-independent Hamiltonians H = (p1^2 + p2^2)/2 + V(q1, q2) whose some integer power qj^nj (t) of the general solution is a singlevalued function of the complez time t. In addition to the well known rational potentials V of Hénon-Heiles, this selects possible cases with a trigonometric dependence of V on qj. Then, by establishing the relevant confluences, we restrict the question of the explicit integration of the seven (three “cubic” plus four “quartic”) rational Hénon-Heiles cases to the quartic cases. Finally, we perform the explicit integration of the quartic cases, thus proving that the seven rational cases have a meromorphic general solution explicitly given by a genus two hyperelliptic function. 展开更多
关键词 two degree of freedom Hamiltonians Painlevé test Painlevé property Hdnon-Heiles Hamiltonian hyperelliptic
下载PDF
Manufacture of End-micro-manipulator with Two Degrees of Freedom and its Driving System for Robot
7
作者 刘劲松 蔡鹤皋 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1995年第1期24-27,共4页
A Robot wrist made of a planar step motor with two-degree-of-freedom has been developed recently for a general robot manipulator used in assembly operation.Mechanism design and the magnetic theory of the motor and the... A Robot wrist made of a planar step motor with two-degree-of-freedom has been developed recently for a general robot manipulator used in assembly operation.Mechanism design and the magnetic theory of the motor and the driving system are discussed. The paper also presents several stecial characteritics in designing general step motor (SM) driver This robot end-effector successfully improves the PUMA562 robot's response and locating accuracy. 展开更多
关键词 ss: two-DEGREE-of-freedom planar SM ROBOT motor driver
下载PDF
A theoretical model to predict the rising trajectory of single bubble with zigzagging path in still water
8
作者 Lubin Zhang Yongli Ma Mingyan Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第10期190-202,共13页
The rising motion of single bubble in still liquid is a natural phenomenon,which has high theoretical research significance and engineering application prospect.Experimental observations and numerical simulations for ... The rising motion of single bubble in still liquid is a natural phenomenon,which has high theoretical research significance and engineering application prospect.Experimental observations and numerical simulations for prediction of the rising trajectory of a single bubble in still liquid are being carried out,while the concise but accurate theoretical or mechanism model is still not well developed.In this article,a theoretical model of a single bubble based on experimental observation of flow around bluff body is proposed to predict the rising trajectory of zigzagging bubbles in still water.The prediction correlation of bubble lateral movement frequency and bubble steer angle are established based on three degrees of freedom frame.The model has achieved good trajectory prediction effect in the bubble rising experiment.The average simulation time per unit moving time of bubble is 2.5 s. 展开更多
关键词 Single bubble Theoretical model Zigzagging Three degrees of freedom frame
下载PDF
Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model
9
作者 SUN Yunqi JIAN Mengnan +2 位作者 YANG Jun ZHAO Yajun CHEN Yijian 《ZTE Communications》 2024年第1期34-40,共7页
Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the ... Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the antenna number.However,recent studies suggest that the DOF could be less than the antenna number when strong mutual coupling is considered.We utilize a mutual-coupling-compliant channel model to investigate the DOF of the holographic MIMO(HMIMO)channel and give a upper bound of the DOF with strong mutual coupling.Our numerical simulations demonstrate that a dense array can support more DOF per unit aperture as compared with a half-wavelength MIMO system. 展开更多
关键词 channel model degree of freedom holographic MIMO mutual coupling
下载PDF
Clinical Effect Observation of Constructing PERMA Model in Psychological Intervention for Patients with Chronic Cancer Pain
10
作者 Yu-Feng Ren Dong-Li Ji +2 位作者 Yu Wu Ru-Qin Ben Hai-Xia Wei 《Psycho-Oncologie》 SCIE 2024年第4期329-336,共8页
Background:The constructing PERMA model in psychological intervention was applied to patients with chronic cancer pain to provide data reference for reducing pain,fear of cancer recurrence,and improving the level of p... Background:The constructing PERMA model in psychological intervention was applied to patients with chronic cancer pain to provide data reference for reducing pain,fear of cancer recurrence,and improving the level of psychological capital.Aim:To explore the clinical effects of constructing PERMA model in psychological intervention for patients with chronic cancer pain.Methods:A total of 98 patients with chronic cancer pain admitted to our hospital from March 2021 to March 2023 were randomly divided into two groups,49 cases in each group.The control group received routine intervention,while the research group constructed PERMA model based on the routine intervention for psychological intervention.The pain severity,fear of cancer recurrence,psychological capital and quality of life before and after intervention were compared between the two groups.Results:After two months of intervention,the pain in the research group was milder than that in the control group(p<0.05).The scores and total scores of all dimensions of fear of cancer recurrence in the research group were lower than those in the control group(p<0.05).The scores and total scores of each dimension of psychological capital in the research group were higher than those in the control group(p<0.05).The scores of all dimensions of quality of life in the research group were higher than those in the control group(p<0.05).Conclusion:The PERMA model constructed in psychological interventions for patients with chronic cancer pain can assist analgesic medications to reduce pain and alleviate the fear of cancer recurrence,increase the level of psychological capital,and thus improve quality of life. 展开更多
关键词 Chronic cancer pain psychological intervention PERMA model degree of pain fear of cancer recurrence psychological capital quality of life
下载PDF
System Identification Modeling of Ship Manoeuvring Motion in 4 Degrees of Freedom Based on Support Vector Machines 被引量:7
11
作者 王雪刚 邹早建 +1 位作者 余龙 蔡韡 《China Ocean Engineering》 SCIE EI CSCD 2015年第4期519-534,共16页
Based on support vector machines, three modeling methods, i.e., white-box modeling, grey-box modeling and black-box modeling of ship manoeuvring motion in 4 degrees of freedom are investigated. With the whole-ship mat... Based on support vector machines, three modeling methods, i.e., white-box modeling, grey-box modeling and black-box modeling of ship manoeuvring motion in 4 degrees of freedom are investigated. With the whole-ship mathematical model for ship manoeuvring motion, in which the hydrodynamic coefficients are obtained from roll planar motion mechanism test, some zigzag tests and turning circle manoeuvres are simulated. In the white-box modeling and grey-box modeling, the training data taken every 5 s from the simulated 20°/20° zigzag test are used, while in the black-box modeling, the training data taken every 5 s from the simulated 15°/15°, 20°/20° zigzag tests and 15°, 25° turning manoeuvres are used; and the trained support vector machines are used to predict the whole 20°/20° zigzag test. Comparisons between the simulated and predicted 20°/20° zigzag tests show good predictive ability of the proposed methods. Besides, all mathematical models obtained by the proposed modeling methods are used to predict the 10°/10° zigzag test and 35° turning circle manoeuvre, and the predicted results are compared with those of simulation tests to demonstrate the good generalization performance of the mathematical models. Finally, the proposed modeling methods are analyzed and compared with each other in aspects of application conditions, prediction accuracy and computation speed. The appropriate modeling method can be chosen according to the intended use of the mathematical models and the available data needed for system identification. 展开更多
关键词 ship manoeuvring 4 degrees of freedom system identification support vector machines
下载PDF
Physical Modeling and Parametric Study on Two-Degree-of-Freedom VIV of A Cylinder near Rigid Wall 被引量:3
12
作者 杨兵 高福平 +1 位作者 李东晖 吴应湘 《China Ocean Engineering》 SCIE EI 2009年第1期119-132,共14页
Unlike most previous studies on the transverse vortex-induced vibration(VlV) of a cylinder mainly under the wallfree condition (Williamson & Govardhan, 2004), this paper experimentally investigates the vortex-ind... Unlike most previous studies on the transverse vortex-induced vibration(VlV) of a cylinder mainly under the wallfree condition (Williamson & Govardhan, 2004), this paper experimentally investigates the vortex-induced vibration of a cylinder with two degrees of freedom near a rigid wall exposed to steady flow. The amplitude and frequency responses of the cylinder are discussed. The lee wake flow patterns of the cylinder undergoin^g VIV were visualized by employing the hydrogen bubble technique. The effects of the gap-to-diameter ratio (eo/D) and the mass ratio on the vibration amplitude and frequency are analyzed. Comparisons of VIV response of the cylinder are made between one degree (only transverse) and two degrees of freedom (streamwise and transverse) and those between the present study and previous ones. The experimental observation indicates that there are two types of streamwise vibration, i.e. the first streamwise vibration (FSV) with small amplitude and the second streamwise vibration (SSV) which coexists with transverse vibration. The vortex shedding pattern for the FSV is approximately syrmnetric and that for the SSV is ahernate. The first streamwise vibration tends to disappear with the decrease of eo/D. For the case of large gap-to-dianeter ratios ( e.g. eo/D = 0. 54 ~ 1.58), the maximum amplitudes of the second streamwise vibration and transverse one increase with the increasing gap- to-diameter ratio. But for the case of small gap-to-diameter ratios (e. g. eo/D= 0. 16, 0.23), the vibration amplitude of the cylinder increases slowly at the initial stage (i.e. at small reduced velocity Vr), and across the maximum amplitude it decreases quickly at the last stage (i.e. at large Vr). Within the range of the examined small mass ratio (m 〈 4), both streamwise and transverse vibration amplitude of the cylinder decrease with the increase of mass ratio for the fixed value of Vr- The vibration range ( in terms of Vr) tends to widen with the decrease of the mass ratio. In the second streamwise vibration region, the vibration frequency of the cylinder with a small mass ratio ( e.g. mx = 1.44) undergoes a jump at a certain Vr+ The maximum amplitudes of the transverse vibration for two-degree-of-freedom case is larger than that for one-degree-of-freedom case, but the transverse vibration frequency of the cylinder with two degrees of freedom is lower than that with one degree of freedom(transverse). 展开更多
关键词 vortex-induced vibration cylinder near a wall two degrees of freedom steady flow gap-to-diameter ratio mass ratio
下载PDF
Existence of two periodic solutions of a ratio-dependent Holling-Taner model with infinite delay and prey harvest 被引量:5
13
作者 TIAN De-sheng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2008年第2期136-142,共7页
This paper considers a class of ratio-dependent Holling-Taner model with infinite delay and prey harvest, which is of periodic coefficients. By means of the coincidence degree theory, a set of sufficient conditions fo... This paper considers a class of ratio-dependent Holling-Taner model with infinite delay and prey harvest, which is of periodic coefficients. By means of the coincidence degree theory, a set of sufficient conditions for the existence of at least two positive periodic solutions of this model is established. 展开更多
关键词 Holling-Taner model RATIO-DEPENDENT HARVEST periodic solution coincidence degree.
下载PDF
Design and Analysis of a Magnetic Bearings with Three Degrees of Freedom 被引量:1
14
作者 Ye Yuan Yukun Sun Qianwen Xiang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第1期142-151,共10页
The current research of supporting and transmission system in flywheel energy storage system(FESS) focuses on the low consumption design. However, friction loss is a non-negligible factor in the high-speed but lightwe... The current research of supporting and transmission system in flywheel energy storage system(FESS) focuses on the low consumption design. However, friction loss is a non-negligible factor in the high-speed but lightweight FESS energy and momentum storage with mechanical-type supporting system. In order to realize the support system without mechanical loss and to maximize the e ciency of the flywheel battery, a permanent magnet biased magnetic bearings(PMBMB) is applied to the FESS with the advantages of low loss, high critical speed, flexible controllability and compact structure. In this frame, the relevant research of three degrees of freedom(3-DOF) PMBMB for a new type FESS is carried out around the working principle, structural composition, coupling characteristics analysis, mathematical model, and structural design. In order to verify the performance of the 3-DOF PMBMB, the radial force mathematical model and the coupling determination equations of radial two DOF are calculated according to an equivalent magnetic circuit, and radial–axial coupling is analyzed through finite element analysis. Moreover, a control system is presented to solve the control problems in practical applications. The rotor returns to the balanced position in 0.05 s and maintains stable suspension. The displacement fluctuation is approximately 40 μm in the y direction and 30 μm in the x direction. Test results indicate that the dynamic rotor of the proposed flywheel energy storage system with PMBMB has excellent characteristics, such as good start-of-suspension performance and stable suspension characteristics. The proposed research provides the instruction to design and control a low loss support system for FESS. 展开更多
关键词 FLYWHEEL energy storage system Magnetic bearings degrees of freedom Coupling FINITE ELEMENT analysis
下载PDF
OPTIMAL CONTROL OF THE FLEXI-BLE LINK MANIPULATOR WITH CONTROLLABLE LOCAL DEGREES OF FREEDOM 被引量:3
15
作者 BIAN Yushu YUN Chao GAO Zhihui 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第4期27-30,共4页
Although flexible manipulators own many potential advantages, one of their major disadvantages is the deterioration of the end-effector accuracy due to the flexibility. Therefore, how to reduce vibration is a signific... Although flexible manipulators own many potential advantages, one of their major disadvantages is the deterioration of the end-effector accuracy due to the flexibility. Therefore, how to reduce vibration is a significant problem. Inspired by the observation on the motion behaviors of animals, a new idea of decreasing motion deflection of the flexible manipulator is suggested. The concept of controllable local degrees of freedom is proposed and analyzed. By way of optimizing local motion provided by the controllable local degrees of freedom, the end-effector deflection of the flexible manipulator can be effectively decreased through dynamic coupling. The corresponding optimal method for vibration control of the flexible manipulator is put forward. The kinematic simulation is carried ant on a three-link flexible manipulator The corresponding results verify the feasibility of this method. 展开更多
关键词 Flexible manipulator Vibration Flexibility Local degree of freedom
下载PDF
Design and Analysis of a Novel Compliant Mechanism with RPR Degrees of Freedom 被引量:1
16
作者 Shuang Zhang Jingfang Liu Huafeng Ding 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2022年第5期262-274,共13页
A novel compliant mechanism with RPR degrees of freedom(DOF)is proposed where R and P represent rotation and translation DOFs,respectively.The proposed compliant mechanism is obtained from dimension synthesizing a 2-R... A novel compliant mechanism with RPR degrees of freedom(DOF)is proposed where R and P represent rotation and translation DOFs,respectively.The proposed compliant mechanism is obtained from dimension synthesizing a 2-RPU-UPR rigid parallel mechanism with the method of optimization of motion/force transfer characteristic.R,P and U represent rotation,translation and universal pairs,respectively.Firstly,inverse kinematics and Jacobian matrix are analyzed for the dimensional synthesis.Then,output transmission indexes of branches in the parallel mechanism are given.Dimensional synthesis is completed based on the normalized design parameter.And optimization of flexure joints based on constrained energy is carried out.Afterwards,the novel compliant mechanism is obtained by direct replacing method.Mechanical model of the compliant mechanism including static stiffness and input stiffness is built based on the pseudo-rigid body modeling method and virtual work principle.Finally,FEA simulation by Ansys Workbench is carried out to verify DOF,effectiveness of the dimension synthesis,and compliant model.Optimization of motion/force transfer characteristic is first applied for the design of compliant mechanisms to suppress drift of rotation axis in the paper. 展开更多
关键词 Compliant mechanism RPR degrees of freedom Motion/force transfer characteristic Mechanical model OPTIMIZATION
下载PDF
Design and Development of a Competitive Low-Cost Robot Arm with Four Degrees of Freedom 被引量:2
17
作者 Ashraf Elfasakhany Eduardo Yanez +1 位作者 Karen Baylon Ricardo Salgado 《Modern Mechanical Engineering》 2011年第2期47-55,共9页
The main focus of this work was to design, develop and implementation of competitively robot arm with en- hanced control and stumpy cost. The robot arm was designed with four degrees of freedom and talented to accompl... The main focus of this work was to design, develop and implementation of competitively robot arm with en- hanced control and stumpy cost. The robot arm was designed with four degrees of freedom and talented to accomplish accurately simple tasks, such as light material handling, which will be integrated into a mobile platform that serves as an assistant for industrial workforce. The robot arm is equipped with several servo motors which do links between arms and perform arm movements. The servo motors include encoder so that no controller was implemented. To control the robot we used Labview, which performs inverse kinematic calculations and communicates the proper angles serially to a microcontroller that drives the servo motors with the capability of modifying position, speed and acceleration. Testing and validation of the robot arm was carried out and results shows that it work properly. 展开更多
关键词 ROBOT Arm LOW-COST Design Validation FOUR degrees of freedom SERVO Motors Arduino ROBOT CONTROL Labview ROBOT CONTROL
下载PDF
Temperature Control Based on Fuzzy Logic Two-degree-of-freedom Smith Internal Model 被引量:4
18
作者 WANG Zhigang HE Meng 《Instrumentation》 2020年第2期1-8,共8页
According to the characteristics of the large time delay,nonlinearity and the great inertia of temperature control system in biomass pyrolysis reactor,a two-degree-of-freedom Smith internal model controller based on f... According to the characteristics of the large time delay,nonlinearity and the great inertia of temperature control system in biomass pyrolysis reactor,a two-degree-of-freedom Smith internal model controller based on fuzzy control is proposed.Firstly,the mathematical model of the temperature control system is established by using the step response method,and then the two-degree-of-freedom Smith internal model controller is designed,and the good tracking performance and disturbance suppression performance can be obtained by designing the set value tracking controller and interference rejection capability.Secondly,the fuzzy control algorithm is used to realize the on-line tuning of the control parameters of the two-degree-of-freedom Smith internal model algorithm.The simulation results show that,compared with the traditional internal model control,fuzzy internal model PID control and two-degree-of-freedom Smith internal model control,the algorithm proposed in this paper improves the influence of lag time on the control system,realizes the separation control of set point tracking and anti-jamming performance and the self-tuning of control parameters,and improves the control performance of the system. 展开更多
关键词 Smith Predictive Controller Internal model Control two degrees of freedom Fuzzy Control Algorithm
下载PDF
Existence of Two Periodic Solutions of a Delayed Single Species Model with Feedback Regulation and Harvest Term 被引量:1
19
作者 TIAN De-sheng CAI Guang-xing YANG Ce-ping 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第3期407-413,共7页
By means of the continuation theorem of the coincidence degree theory,the existence of two periodic solutions of a delayed single species model with feedback regulation and harvest term is obtained.
关键词 two periodic solutions delayed single-species model feedback regulation and harvest term continuation theorem of the coincidence degree theory
下载PDF
Nonlinear dynamics of two degree of freedom systems with linear and nonlinear stiffnesses 被引量:2
20
作者 Bayat Mahmoud I.Pakar 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第3期411-420,共10页
In this study, a new analytical approach is developed to analyze the free nonlinear vibration of conservative two-degree-of-freedom (TDOF) systems. The mathematical models of these systems are governed by second--or... In this study, a new analytical approach is developed to analyze the free nonlinear vibration of conservative two-degree-of-freedom (TDOF) systems. The mathematical models of these systems are governed by second--order nonlinear partial differential equations. Nonlinear differential equations were transferred into a single equation by using some intermediate variables. The single nonlinear differential equations are solved by using the first order of the Hamiltonian approach (HA). Different parameters, which have a significant impact on the response of the systems, are considered and discussed. Some comparisons are presented to verify the results between the Hamiltonian approach and the exact solution. The maximum relative error is less than 2.2124 % for large amplitudes of vibration. It has been established that the first iteration of the Hamiltonian approach achieves very accurate results, does not require any small perturbations, and can be used for a wide range of nonlinear problems. 展开更多
关键词 nonlinear vibration two-degree-of-freedom (TDof analytical approach Hamitonian approach (HA)
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部