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RESEARCH ON THE CONSTRAINT MAPPING FROM FUNCTION TO ASSEMBLY 被引量:3
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作者 Tan JianrongJi YangjianLiu ZhenyuChen HongliangYue XiaoliState Key Laboratory of CAD&CG,Zhejiang University,Hangzhou 310027, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第3期305-308,共4页
Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most research... Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most researches are aimed at bow to obtain Structures fromfunction, but the problem of how to obtain assembly constraint from function is ignored. Followingthe definition of assembly unit and the classification of function, a hierarchical mapping methodfrom function to assembly constraint is put forward, and the mapping method includes two steps. Thefirst step is the mapping from function to assembly semantics which is assembly expression andaccordant with engineer's design habit. The second one is the mapping from assembly semantics tobasic assembly constraints that are convenient for computer to handle. The mapping method is appliedto DDMS (design, drafting and management system) successfully. 展开更多
关键词 constraint mapping Assembly constraint Assembly design function design
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Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Ⅱ: Material Function with Nagai Chain Constraints and Determination of Their Parameters from Flow Curves 被引量:3
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作者 Mingshi SONG Sizhu WU and Xiuyun DU(Research Institute of Polymeric Materials, Beijing University of Chemical Technology, Beijing, 100029, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第2期141-152,共12页
An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the de... An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the dependence of ηo and τt on M3.4 were derived from the theory of non-linear viscoelasticity with constraints of entanglements for polymer melts and substituted into the Oldroye-Walters-Fredickson constitutive equation. An integral constitutive equation for polymer melts was consequently obtained. Some material functions of the constitutive equation related to certain 'test flow' are examined as follows : (1) simple steady shear flow; (2) steady elongation flow; (3) small-amplitude oscillatory shear flow; (4) stress growth upon the inception of steady shear elongation flow; (5) stress relaxation (modulus and compllance). These theoretical relations for simple steady shear flow were compared with experimental data from our laboratory and references for various polymer melts and concentrated solutions. A good agreement between the theory and experiment was achieved. 展开更多
关键词 LDPE Material function with Nagai Chain constraints and Determination of Their Parameters from Flow Curves Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Flow GR
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Constraint-induced movement therapy promotes brain functional reorganization in stroke patients with hemiplegia 被引量:4
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作者 Wenqing Wang Aihui Wang +5 位作者 Limin Yu Xuesong Han Guiyun Jiang Changshui Weng Hongwei Zhang Zhiqiang Zhou 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第32期2548-2553,共6页
Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitat... Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitation technique used in stroke patients with hemiplegia; however, studies of lower extremity rehabilitation are scarce. In this study, stroke patients with lower limb hemiplegia underwent conventional Bobath therapy for 4 weeks as baseline treatment, followed by constraint-induced movement therapy for an additional 4 weeks. The 10-m maximum walking speed and Berg balance scale scores significantly improved following treatment, and lower extremity motor function also improved. The results of functional MRI showed that constraint-induced movement therapy alleviates the reduction in cerebral functional activation in patients, which indicates activation of functional brain regions and a significant increase in cerebral blood perfusJon. These results demonstrate that constraint-induced movement therapy promotes brain functional reorganization in stroke patients with lower limb hemiplegia. 展开更多
关键词 STROKE constraint-induced movement therapy functional MRI lower extremity maximum walking speed Berg balance scale central nervous injury NEUROIMAGING REGENERATION neural regeneration
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Admissible Linear Estimators of Multivariate Regression Coefcient with Respect to an Inequality Constraint under Balanced Loss Function
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作者 Jie WU Daojiang HE 《Journal of Mathematical Research with Applications》 CSCD 2013年第6期745-752,共8页
In this paper, the admissibility of multivariate linear regression coefficient with respect to an inequality constraint under balanced loss function is investigated. Necessary and sufficient conditions for admissible ... In this paper, the admissibility of multivariate linear regression coefficient with respect to an inequality constraint under balanced loss function is investigated. Necessary and sufficient conditions for admissible homogeneous and inhomogeneous linear estimators are obtained, respectively. 展开更多
关键词 ADMISSIBILITY inequality constraint balanced loss function homogeneous (inhomogeneous) linear estimator.
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Taking into Account of Functional Constraints in Optimization of Modes of Power Systems by Genetic Algorithms
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作者 Gayibov Tulkin Shernazarovich Latipov Sherkhon Shuxratovich 《Engineering(科研)》 2019年第4期240-246,共7页
The development of the capabilities of computational tools has created up new possibilities for the effective use of a number of classical mathematical methods and algorithms for solving many important problems in the... The development of the capabilities of computational tools has created up new possibilities for the effective use of a number of classical mathematical methods and algorithms for solving many important problems in the power engineering. In particular, a set of algorithms are developed to optimize the modes of electric power systems based on genetic algorithms. At the same time, the issues of taking into account functional constraints in solving such problems by genetic algorithms need to be improved. In accordance with it in this article the problems of taking into account of different constraints in optimization of modes of power systems using genetic algorithms are considered. The algorithm of optimization by genetic algorithm taking into account of functional constraints in forms of equality and inequality by penalty functions is proposed. The results of research of proposed algorithm’s efficiency in example of optimization of mode of power system with 8 buses, 4 thermal power plants and 3 transmission lines with controlled power flow are presented. 展开更多
关键词 OPTIMIZATION POWER System POWER Plant Objective function constraint
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Functional magnetic resonance imaging evaluation of brain function reorganization in cerebral stroke patients after constraint-induced movement therapy
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作者 Jun Zhao Tong Zhang +2 位作者 Jianmin Xu Mingli Wang Shengjie Zhao 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第15期1158-1163,共6页
In this study, stroke patients received constraint-induced movement therapy for 3 weeks. Before and after constraint-induced movement therapy, the flexibility of their upper limbs on the affected side was assessed usi... In this study, stroke patients received constraint-induced movement therapy for 3 weeks. Before and after constraint-induced movement therapy, the flexibility of their upper limbs on the affected side was assessed using the Wolf motor function test, and daily use of their affected limbs was assessed using the movement activities log, and cerebral functional reorganization was assessed by functional magnetic resonance imaging. The Wolf motor function test score and the movement activities log quantity and quality scores were significantly increased, while action performance time in the Wolf motor function test was significantly decreased after constraint-induced movement therapy. By functional magnetic resonance imaging examination, only scattered activation points were visible on the affected side before therapy. In contrast, the volume of the activated area was increased after therapy. The activation volume in the sensorimotor area was significantly different before and after therapy, and the activation area increased and appeared adjusted. In addition to the activated area around the lesions being decreased, there were also some new activated areas, including the supplementary movement area, premotor area and the ipsilateral sensorimotor area. Our findings indicate that constraint-induced movement therapy significantly improves the movement ability and daily use of the affected upper limbs in stroke patients and promotes cerebral functional reorganization. 展开更多
关键词 cerebral stroke constraint-induced movement functional magnetic resonance imaging cerebralfunctional reorganization REHABILITATION motor function of upper limbs neural regeneration
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A Penalty Function Algorithm with Objective Parameters and Constraint Penalty Parameter for Multi-Objective Programming
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作者 Zhiqing Meng Rui Shen Min Jiang 《American Journal of Operations Research》 2014年第6期331-339,共9页
In this paper, we present an algorithm to solve the inequality constrained multi-objective programming (MP) by using a penalty function with objective parameters and constraint penalty parameter. First, the penalty fu... In this paper, we present an algorithm to solve the inequality constrained multi-objective programming (MP) by using a penalty function with objective parameters and constraint penalty parameter. First, the penalty function with objective parameters and constraint penalty parameter for MP and the corresponding unconstraint penalty optimization problem (UPOP) is defined. Under some conditions, a Pareto efficient solution (or a weakly-efficient solution) to UPOP is proved to be a Pareto efficient solution (or a weakly-efficient solution) to MP. The penalty function is proved to be exact under a stable condition. Then, we design an algorithm to solve MP and prove its convergence. Finally, numerical examples show that the algorithm may help decision makers to find a satisfactory solution to MP. 展开更多
关键词 MULTI-OBJECTIVE Programming PENALTY function Objective PARAMETERS constraint PENALTY Parameter PARETO Weakly-Efficient Solution
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带有定量超调约束的吸引预设性能控制方法
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作者 张天琦 李新凯 +1 位作者 孟月 张宏立 《哈尔滨工业大学学报》 北大核心 2026年第1期65-76,共12页
为完善非线性系统预设性能跟踪控制过程中约束冲突问题的处理机制,并对系统施加更精细的约束,本文提出了一种基于新型可变障碍函数的性能约束控制方法。首先,对非线性系统约束控制中因初始状态不确定和期望轨迹突变导致的约束冲突问题... 为完善非线性系统预设性能跟踪控制过程中约束冲突问题的处理机制,并对系统施加更精细的约束,本文提出了一种基于新型可变障碍函数的性能约束控制方法。首先,对非线性系统约束控制中因初始状态不确定和期望轨迹突变导致的约束冲突问题进行分析,提出了一种新的非对称可变障碍函数构型。该构型为系统引入了吸引函数,能够统一处理约束冲突过程中的约束解除和约束恢复两个阶段,并能够丰富预设性能边界的设置形式,使得约束控制策略更加简单和完善。其次,基于设计的新型非对称可变障碍函数构型,设计一组新型L型预设性能边界函数。该组性能边界函数本身具有约束力,能够对系统输出的超调量施加定量约束,从而更精细地约束系统的行为。最后,对系统误差的有界性和前向不变性进行了证明,并基于Lyapunov函数稳定性理论证明所有闭环信号的一致最终有界性。选取四旋翼无人机系统进行数值仿真和实验对比,数值仿真和实验结果验证了所提方案的有效性和优越性。本文设计的吸引预设性能方法,能够在给系统施加定量超调约束的同时,解决约束过程中产生的约束冲突问题。 展开更多
关键词 自适应控制 可变障碍函数 超调约束 约束冲突 预设性能控制
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Moult intensity constraints along the complete moult sequence of the House Sparrow(Passer domesticus) 被引量:1
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作者 Santi Guallar Javier Quesada 《Avian Research》 SCIE CSCD 2023年第3期394-404,共11页
Sequence and intensity are two essential components of bird moult.While the moult sequences of remex tracts are highly homogenous across passerines,other tracts apparently show a high variability.Moreover,order of mou... Sequence and intensity are two essential components of bird moult.While the moult sequences of remex tracts are highly homogenous across passerines,other tracts apparently show a high variability.Moreover,order of moult activation among tracts are insufficiently known.Likewise,dynamics of moult intensity as moult progresses remains poorly known.Here,we provide detailed quantitative description of moult sequence and intensity in the House Sparrow(Passer domesticus).To understand their role,we tested two hypotheses on the:1) protection function of moult sequence,and 2) aerodynamic and physiological constraints on moult intensity.We scored percentage growth of 313 captured sparrows using the mass of the feathers of each tract(also length for remiges)to monitor moult intensity throughout the complete moult progress,which is defined as the fraction of new and growing feathers in a moulting bird relative to the total plumage.Moult sequence was highly variable both within wing coverts and among feather tracts,with moult sequence differing among all birds to some degree.We only found support for the protection function between greater coverts and both tertials and secondaries.Remex-moult intensity conformed to theoretical predictions,therefore lending support to the aerodynamic-constraint hypothesis.Furthermore,remex-moult speed plateaued during the central stages of moult progress.However,overall plumage-moult speed did not fit predictions of the physiological-constraint hypothesis,showing that the remex moult is only constrained by aerodynamics.Our results indicate that aerodynamic loss is not simply the inevitable effect of moult,but that moult is finely regulated to reduce aerodynamic loss.We propose that the moult of the House Sparrow is controlled through sequence and intensity adjustments in order to:1) avoid body and wing growth peaks;2) fulfil the protection function between some key feather tracts;3) reduce detrimental effects on flight ability;4) keep remex sequence fixed;and 5) relax remex replacement to last the whole moult duration. 展开更多
关键词 functional constraints Local polynomial regression Passerine moult Physiological constraints Raggedness
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机械臂在状态约束条件下的固定时间收敛滑模控制
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作者 杨忠君 刘一泽 李柏霖 《电光与控制》 北大核心 2026年第1期84-90,共7页
针对具有关节角位移时变约束、外部干扰和执行器故障情况下的机械臂控制问题,首先,设计了基于边界函数的干扰观测器估计系统中的集总扰动,该集总扰动由外部干扰和执行器故障组成,且不需要已知其上界;随后,提出了一种新型非奇异终端滑模... 针对具有关节角位移时变约束、外部干扰和执行器故障情况下的机械臂控制问题,首先,设计了基于边界函数的干扰观测器估计系统中的集总扰动,该集总扰动由外部干扰和执行器故障组成,且不需要已知其上界;随后,提出了一种新型非奇异终端滑模面和正切型障碍Lyapunov函数,并结合性能函数有效解决了机械臂角位移的约束问题,通过稳定性分析,证明了系统的状态变量能够在固定时间内收敛稳定,且收敛时间不受初始状态的影响;最后,通过仿真对比实验表明,与现有控制策略相比,所提出的策略能够显著加快机械臂的收敛速度,增强系统的抗干扰能力,从而验证了所提控制策略的有效性。 展开更多
关键词 滑模控制 障碍函数 执行器故障 固定时间收敛 状态约束
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A New Evolutionary Algorithm for Function Optimization 被引量:37
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作者 GUO Tao, KANG Li shan State Key Laboratory of Software Engineering, Wuhan University,Wuhan 430072, China 《Wuhan University Journal of Natural Sciences》 CAS 1999年第4期409-414,共6页
A new algorithm based on genetic algorithm(GA) is developed for solving function optimization problems with inequality constraints. This algorithm has been used to a series of standard test problems and exhibited good... A new algorithm based on genetic algorithm(GA) is developed for solving function optimization problems with inequality constraints. This algorithm has been used to a series of standard test problems and exhibited good performance. The computation results show that its generality, precision, robustness, simplicity and performance are all satisfactory. 展开更多
关键词 Key words evolutionary algorithm function optimization problem inequality constraints
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Regularized inversion for coseismic slip distribution with active constraint balancing 被引量:2
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作者 TONG Xiao-zhong XIE Wei GAO Da-wei 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第12期2961-2968,共8页
Estimating the spatial distribution of coseismic slip is an ill-posed inverse problem, and solutions may be extremely oscillatory due to measurement errors without any constraints on the coseismic slip distribution. I... Estimating the spatial distribution of coseismic slip is an ill-posed inverse problem, and solutions may be extremely oscillatory due to measurement errors without any constraints on the coseismic slip distribution. In order to obtain stable solution for coseismic slip inversion, regularization method with smoothness-constrained was imposed. Trade-off parameter in regularized inversion, which balances the minimization of the data misfit and model roughness, should be a critical procedure to achieve both resolution and stability. Then, the active constraint balancing approach is adopted, in which the trade-off parameter is regarded as a spatial variable at each model parameter and automatically determined via the model resolution matrix and the spread function. Numerical experiments for a synthetical model indicate that regularized inversion using active constraint balancing approach can provides stable inversion results and have low sensitivity to the knowledge of the exact character of the Gaussian noise. Regularized inversion combined with active constraint balancing approach is conducted on the 2005 Nias earthquake. The released moment based on the estimated coseismic slip distribution is 9.91×1021 N·m, which is equivalent to a moment magnitude of 8.6 and almost identical to the value determined by USGS. The inversion results for synthetic coseismic uniform-slip model and the 2005 earthquake show that smoothness-constrained regularized inversion method combined with active constraint balancing approach is effective, and can be reasonable to reconstruct coseismic slip distribution on fault. 展开更多
关键词 COSEISMIC SLIP INVERSION trade-off parameter ACTIVE constraint balancing model resolution matrix spread function
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基于有限状态机的六足机器人人机协同指令优选方法 被引量:1
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作者 尤波 董正 +3 位作者 李佳钰 陈潇磊 陈晨 丁亮 《控制与决策》 北大核心 2025年第1期327-335,共9页
针对六足机器人在复杂环境下如何决策出最优人机指令组合问题,提出将操控指令权限分配的过程分为离线和在线两个阶段.在离线阶段,将六足机器人运动过程中机身的稳定裕度、能量消耗和与障碍物的碰撞接触时间作为指令优选的约束条件,并建... 针对六足机器人在复杂环境下如何决策出最优人机指令组合问题,提出将操控指令权限分配的过程分为离线和在线两个阶段.在离线阶段,将六足机器人运动过程中机身的稳定裕度、能量消耗和与障碍物的碰撞接触时间作为指令优选的约束条件,并建立评价函数实现在进入地形前获得最优的操控指令组合;在线阶段,依据上述3个约束条件量化有限状态机网络中的状态转移概率,并人为设置约束条件阈值作为触发条件,向最优的人机决策指令状态进行转换.最后利用半物理仿真系统进行实验,结果表明所提出的决策方法在稳定裕度上相对于其他操控方法提高约15%~25%;能量消耗上降低了约10%~50%;碰撞接触时间降低了约10%~50%. 展开更多
关键词 六足机器人 有限状态机 协同决策 指令优选 约束条件 评价函数
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Constraint-induced movement therapy in treatment of acute and sub-acute stroke: a meta-analysis of 16 randomized controlled trials 被引量:11
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作者 Xi-hua Liu Juan Huai +2 位作者 Jie Gao Yang Zhang Shou-wei Yue 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第9期1443-1450,共8页
OBJECTIVE: The aim of this meta-analysis was to evaluate the clinical efficacy of constraint-induced movement therapy in acute and sub-acute stroke. DATA SOURCES: The key words were stroke, cerebrovascular accident,... OBJECTIVE: The aim of this meta-analysis was to evaluate the clinical efficacy of constraint-induced movement therapy in acute and sub-acute stroke. DATA SOURCES: The key words were stroke, cerebrovascular accident, constraint-induced therapy, forced use, and randomized controlled trial. The databases, including China National Knowledge Infrastructure, WanFang, Weipu Information Resources System, Chinese Biomedical Literature Database, PubMed, Med- line, Embase, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews, were searched for studies on randomized controlled trials for treating acute or sub-acute stroke published before March 2016. DATA SELECTION: We retrieved relevant randomized controlled trials that compared constraint-induced movement therapy in treatment of acute or sub-acute stroke with traditional rehabilitation therapy (tradi- tional occupational therapy). Patients were older than 18 years, had disease courses less than 6 months, and were evaluated with at least one upper extremity function scale. Study quality was evaluated, and data that met the criteria were extracted. Stata 11.0 software was used for the meta-analysis. OUTCOME MEASURES: Fugl-Meyer motor assessment of the arm, the action research-arm test, a motor activity log for amount of use and quality of movement, the Wolf motor function test, and a modified Bar- thel index. RESULTS: A total of 16 prospective randomized controlled trials (379 patients in the constraint-induced movement-therapy group and 359 in the control group) met inclusion criteria. Analysis showed significant mean differences in favor of constraint-induced movement therapy for the Fugl-Meyer motor assessment of the arm (weighted mean difference (WMD) = 10.822; 95% confidence intervals (95% CI): 7.419-14.226), the action research-arm test (WMD = 10.718; 95% CI: 5.704-15.733), the motor activity log for amount of use and quality of movement (WMD = 0.812; 95% CI: 0.331-1.293) and the modified Barthel index (WMD = 10.706; 95% CI: 4.417-16.966). CONCLUSION: Constraint-induced movement therapy may be more beneficial than traditional rehabili- tation therapy for improving upper limb function after acute or sub-acute stroke. 展开更多
关键词 nerve regeneration STROKE constraint-induced movement therapy META-ANALYSIS upper extremity function REHABILITATION INTENSITY neural regeneration
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SEQUENTIAL QUADRATIC PROGRAMMING METHODS FOR OPTIMAL CONTROL PROBLEMS WITH STATE CONSTRAINTS
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作者 徐成贤 Jong de J. L. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1993年第2期163-174,共12页
A kind of direct methods is presented for the solution of optimal control problems with state constraints. These methods are sequential quadratic programming methods. At every iteration a quadratic programming which i... A kind of direct methods is presented for the solution of optimal control problems with state constraints. These methods are sequential quadratic programming methods. At every iteration a quadratic programming which is obtained by quadratic approximation to Lagrangian function and linear approximations to constraints is solved to get a search direction for a merit function. The merit function is formulated by augmenting the Lagrangian function with a penalty term. A line search is carried out along the search direction to determine a step length such that the merit function is decreased. The methods presented in this paper include continuous sequential quadratic programming methods and discreate sequential quadratic programming methods. 展开更多
关键词 Optimal Control Problems with State constraints Sequential Quadratic Programming Lagrangian function. Merit function Line Search.
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输入输出受限的机械臂自适应反步滑模控制 被引量:2
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作者 张蕾 田荣 袁媛 《西安工程大学学报》 2025年第2期10-18,共9页
针对机械臂在运行过程中因输入输出受限、外界未知干扰以及自身动力学参数不确定性导致控制精度低和抗干扰能力差的问题,提出基于时变正切型障碍李雅普诺夫函数的自适应反步滑模控制方法(adaptive backstepping sliding mode control fo... 针对机械臂在运行过程中因输入输出受限、外界未知干扰以及自身动力学参数不确定性导致控制精度低和抗干扰能力差的问题,提出基于时变正切型障碍李雅普诺夫函数的自适应反步滑模控制方法(adaptive backstepping sliding mode control for time-varying tangent barrier Lyapunov,TTBLF-ABSMC)。首先,通过设计饱和补偿系统解决输入受限问题,提高控制系统的稳定性;其次,将外界未知干扰与自身动力学参数不确定性视为复合干扰,设计反馈自适应律对其做出准确估计;同时,采用时变正切型障碍李雅普诺夫函数将位置误差和速度误差限制在时变范围内;最后,通过李雅普诺夫理论分析证明闭环控制系统是有界稳定的。仿真实验结果表明:与采取时变对数型障碍李雅普诺夫函数的控制方法相比,该控制方法使机械臂关节1、2的跟踪误差分别降低了58%、33%;相比于未考虑输入受限方法,该控制方法在关节1、2的轨迹跟踪响应速度分别提升了69%、50%,有效的提高了系统的控制精度和抗干扰能力。 展开更多
关键词 轨迹跟踪控制 输入输出约束 障碍李雅普诺夫函数 自适应控制
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THE CHARACTERIZATION OF EFFICIENCY AND SADDLE POINT CRITERIA FOR MULTIOBJECTIVE OPTIMIZATION PROBLEM WITH VANISHING CONSTRAINTS
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作者 Anurag JAYSWAL Vivek SINGH 《Acta Mathematica Scientia》 SCIE CSCD 2019年第2期382-394,共13页
In this article, we focus to study about modified objective function approach for multiobjective optimization problem with vanishing constraints. An equivalent η-approximated multiobjective optimization problem is co... In this article, we focus to study about modified objective function approach for multiobjective optimization problem with vanishing constraints. An equivalent η-approximated multiobjective optimization problem is constructed by a modification of the objective function in the original considered optimization problem. Furthermore, we discuss saddle point criteria for the aforesaid problem. Moreover, we present some examples to verify the established results. 展开更多
关键词 MULTIOBJECTIVE optimization problem with VANISHING constraintS efficient solution INVEXITY η-Lagrange function SADDLE point
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Hybrid Predictive Control Based on High-Order Differential State Observers and Lyapunov Functions for Switched Nonlinear Systems 被引量:1
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作者 Baili Su Guoyuan Qi Barend J. van Wyk 《Applied Mathematics》 2013年第9期32-42,共11页
In this paper, a hybrid predictive controller is proposed for a class of uncertain switched nonlinear systems based on high-order differential state observers and Lyapunov functions. The main idea is to design an outp... In this paper, a hybrid predictive controller is proposed for a class of uncertain switched nonlinear systems based on high-order differential state observers and Lyapunov functions. The main idea is to design an output feedback bounded controller and a predictive controller for each subsystem using high-order differential state observers and Lyapunov functions, to derive a suitable switched law to stabilize the closed-loop subsystem, and to provide an explicitly characterized set of initial conditions. For the whole switched system, based on the high-order differentiator, a suitable switched law is designed to ensure the whole closed-loop’s stability. The simulation results for a chemical process show the validity of the controller proposed in this paper. 展开更多
关键词 SWITCHED System LYAPUNOV function High Order DIFFERENTIATOR CONTROL constraint Output Feedback Model Predictive CONTROL Stable Region
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不同性能约束的永磁直线电机变增益超螺旋控制
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作者 殷春武 易佩 赵紫兰 《探测与控制学报》 北大核心 2025年第6期126-132,共7页
针对固定增益会导致初始控制输入较大和传统滑模控制存在抖振等问题,对存在参数摄动和外部干扰的永磁直线电机(PMLM)系统,设计了一种变增益超螺旋预设性能控制器,使PMLM的位置跟踪误差按照预设性能收敛。采用误差转换策略将受性能约束... 针对固定增益会导致初始控制输入较大和传统滑模控制存在抖振等问题,对存在参数摄动和外部干扰的永磁直线电机(PMLM)系统,设计了一种变增益超螺旋预设性能控制器,使PMLM的位置跟踪误差按照预设性能收敛。采用误差转换策略将受性能约束函数约束的跟踪误差变量转化为无约束变量,利用极限学习机在线估计由参数摄动和外部干扰构成的复合干扰,为不确定性PMLM系统设计了一种增益可自适应调整的超螺旋有限时间控制算法,理论证明了闭环系统的有限时间稳定性。6种不同预设性能约束函数下的数值仿真,验证了所设计算法的有效性。结果表明,变增益超螺旋控制器能有效降低初始控制力矩和综合能耗,避免控制器的抖振现象;不同的预设性能约束函数会导致PMLM的位置跟踪精度、收敛时间和综合能耗存在差异。 展开更多
关键词 永磁直线电机 预设性能控制 预设性能约束函数 超螺旋控制
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高空舱抽气系统内罚协同优化控制设计与应用
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作者 黄艳 张和洪 +4 位作者 翟超 但志宏 李晓冬 张楼悦 王鹏 《推进技术》 北大核心 2025年第7期235-249,共15页
高空舱抽气调控系统通过协调控制多个调节阀将压缩机组并网至抽气管网,建立起发动机的环境背压,实现发动机试验的飞行高度模拟。针对抽气调控系统多压缩机组并网过程中效率低、压缩机组压比易超出安全裕度以及抽气管网压力控制品质不佳... 高空舱抽气调控系统通过协调控制多个调节阀将压缩机组并网至抽气管网,建立起发动机的环境背压,实现发动机试验的飞行高度模拟。针对抽气调控系统多压缩机组并网过程中效率低、压缩机组压比易超出安全裕度以及抽气管网压力控制品质不佳等问题,提出一种基于内罚函数的协同优化控制方案与算法。针对压缩机组并网安全运行问题,建立基于内罚函数的安全约束压力优化框架;考虑并网效率低、压力控制品质不佳问题,结合自抗扰控制(ADRC)与PI控制,设计基于内罚函数的协同优化控制算法;模拟多种实际试验工况仿真验证所提出的方案与算法。结果表明:相较于当前采用的独立控制,所提算法能确保机组安全运行的同时提高系统并网效率和控制品质。在发动机排气流量突增、突降扰动工况中,被控压力达到设定值的时间缩短了16.5%,流量突增、突降导致的被控压力最大瞬时波动量分别减小了13.4%,15.5%,调节时间缩短了56%,控制稳定无超调,核心控制阀门摆动量从5%降至0.32%。 展开更多
关键词 高空舱 压缩机组 安全约束 内罚函数 协同优化控制
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