共查询到18条相似文献，搜索用时 203 毫秒
1.
双向偏心结构扭转耦联地震反应的序列最优控制 总被引：1，自引：0，他引：1
本文分析了不对称建筑结构平移-扭转耦联振动的动力特性及地震作用下的响应;根据地震动输入结构的过程,推导出一种更为一般的最优控制算法,所获得的控制力表达式同时包括地震响应和地震激励。通过对一非规则四层框架结构的扭转耦联地震反应控制分析表明,该算法不仅能有效地控制结构的平移地震反应,而且更有效地抑制结构的扭转耦联地震反应。 相似文献
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高阶单步法控制MR智能隔震系统的试验研究 总被引：1，自引：0，他引：1
高阶单步法已成功地应用于结构非线性分析及考虑时滞的主动控制等，显示了它的稳定、精度高和计算迅速等特点。磁流变阻尼器是一种性能优良的智能阻尼器，它具有阻尼力可调范围宽、响应迅速且所需能量很少的特点。本文将磁流变（MR）阻尼器与普通橡胶隔震支座相结合，采用高阶单步算法和两种控制策略对结构进行振动控制。数值模拟分析与振动台试验结果表明：由MR阻尼器提供可调阻尼力的智能隔震控制系统能有效克服被动隔震最优控制频带窄的缺点，对较宽频域范围不同大小的地震激励均能提供最优控制。同时也表明该控制算法是一种能用于结构实际控制的变阻尼有效算法。 相似文献
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基于瞬时最优控制算法和经典的线性二次型高斯（Gauss）控制算法．推导了三种前馈-反馈算法．其控制器的设计包含两个部分：基于传统控制算法的反馈部分和在采样时间内对地震动信息的前馈部分。以在建的某电视塔（610m）为例。通过跟常用的线性二次型高斯（Gauss）闭环反馈控制算法相比较,对比分析了这三种前馈-反馈算法在地震作用下．对结构反应的控制效果;针对规范中对层间位移角和舒适度的要求．深入研究了在三种不同的控制目标下,基于LQG前馈-反馈算法（FFLQG）对结构反应控制的有效性：最后。通过一种新的权系数选择方法,研究了不同的输出反馈对基于LQG前馈-反馈算法控制效果的影响。 相似文献
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《地震工程与工程振动》2015,(1)
最优控制方法是利用极值原理、最优滤波或动态规划等最优化方法来求解结构振动最优控制输入的一种设计方法。最优控制规律均是建立在系统理想数学模型基础上,而实际结构控制中往往采用降阶模型且存在多种约束条件,因此基于最优控制理论设计的控制器大都只能实现次最优控制。迭代学习控制理论的产生与发展,为结构振动主动控制提供了新的方法,但迭代学习控制的应用又受到其控制效果与其收敛性的制约。本文基于线性二次型最优控制与迭代学习控制相结合的思想,提出二次型最优迭代学习混合控制方法(LQILC),以二次型性能指标为控制目标,提高迭代的收敛速度;在性能指标的基础上进行迭代学习,改善了二次型最优控制的控制效果。以Emerson Memorial斜拉桥Benchmark模型为研究对象,采用二次型迭代学习控制策略(LQILC)对该桥的地震响应进行有效的控制,并得出Benchmark指标评价其对该桥的控制效果。 相似文献
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曲线梁桥由于其平面不规则性导致结构在地震激励下产生弯扭耦合效应,使得隔震曲线梁桥的地震响应更加复杂。目前常用的控制方法是将隔震技术与附加减震装置相结合对曲线梁桥进行控制。本文将地震动考虑为一均匀调制非平稳随机过程,针对隔震曲线梁桥长周期、低频率的特点,选取Clough-Pension平稳地震动功率谱模型作为随机地震动输入模型,对无控(NON-C)、经典线性最优控制(COC)以及序列最优控制算法(SOC)三种状态下的曲线桥梁进行随机响应分析。通过建立曲线梁桥在随机地震动作用下的运动方程,求出减震控制结构的位移谱密度、加速度谱密度响应及时变方差。分析结果表明:序列最优控制算法(SOC)在使隔震层位移得到减小的同时,可以更有效地控制上部结构的地震响应,具有更好的控制效果。 相似文献
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磁流变智能基础隔震系统研究 总被引：5，自引：3，他引：2
本文将磁流变(MR)阻尼器与普通橡胶隔震支座相结合,组成智能基础隔震系统应用到结构控制中。在详细介绍了系统的各部分与整体运行情况后,采用LQR经典线性最优控制算法对结构进行了振动台试验研究。试验结果表明,由MR阻尼器提供可调阻尼力的智能隔震控制系统,能有效克服被动隔震最优控制频带窄的缺点,对较宽频域范围地震激励能进行有效的振动控制。其相对一般被动隔震装置,能同时减小上部结构加速度和隔震层位移. 相似文献
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主动结构振动控制算法综述 总被引：8，自引：0，他引：8
系统介绍了结构振动主动控制常用的七种算法,包手龙典线最优控制,极点地,时最优控制,狡模态控制,Ｈ∞状态反馈控制,滑动模态控制及最优多项式控制。 相似文献
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介绍了一种具有自主知识产权的新型开关控制型半主动控制系统——主动变刚度.阻尼(AVS.D)系统的减振控制机理,建立了AVS.D结构振动控制体系的运动方程。为了合理补偿AVS.D系统实时控制过程中不可避免地存在着的控制时滞,本文提出一种预测最优控制算法,推导了其开关控制律。为了检验AVS.D系统的减震控制效果及预测最优控制算法的有效性,我们设计研制出AVS.D装置,编制了AVS.D系统预测最优控制的实时控制软件,在某单层钢框架模型上进行了AVS.D系统的模拟地震振动台试验,比较了不同控制方式时的减震效果。研究结果表明,本文所提出的预测最优控制算法是非常有效的,可推广应用于所有开关控制型半主动控制系统。AVS.D系统具有反应放大功能,经济可靠、安全有效,可望有较好的工程应用前景。 相似文献
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主动变刚度／阻尼控制算法研究 总被引：10，自引：2，他引：8
建立了主动变刚度／阻尼控制系统的理论模型;基于瞬时最优控制算法推导了ＡＶＳＤ系统的开关控制律,并从控制结构的层间位移出发提出了一种直接根据结构动力反应符号确定的开关控制律。 相似文献
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Lyan‐Ywan Lu 《地震工程与结构动力学》2004,33(5):647-668
In this paper a predictive control method especially suitable for the control of semi‐active friction dampers is proposed. By keeping the adjustable slip force of a semi‐active friction damper slightly lower than the critical friction force, the method allows the damper to remain in its slip state throughout an earthquake of arbitrary intensity, so the energy dissipation capacity of the damper can be improved. The proposed method is formulated in a discrete‐time domain and cast in the form of direct output feedback for easy control implementation. The control algorithm is able to produce a continuous and smooth slip force for a friction damper and thus avoid exerting the high‐frequency structural response that usually exists in structures with conventional friction dampers. Using a numerical study, the control performance of a multiple degrees of freedom (DOF) structural system equipped with passive friction dampers and semi‐active dampers controlled by the proposed method are compared. The numerical case shows that by merely using a single semi‐active friction damper and a few sensors, the proposed method is able to achieve better acceleration reduction than the case using multiple passive dampers. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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In this paper, an effective active predictive control algorithm is developed for the vibration control of non-linear hysteretic structural systems subjected to earthquake excitation. The non-linear characteristics of the structural behaviour and the effects of time delay in both the measurements and control action are included throughout the entire analysis (design and validation). This is very important since, in current design practice, structures are assumed to behave non-linearly, and time delays induced by sensors and actuator devices are not avoidable. The proposed algorithm focuses on the instantaneous optimal control approach for the development of a control methodology where the non-linearities are brought into the analysis through a non-linear state vector and a non-linear open-loop term. An autoregressive (AR) model is used to predict the earthquake excitation to be considered in the prediction of the structural response. A performance index that is quadratic in the control force and in the predicted non-linear states, with two additional energy related terms, and that is subjected to a non-linear constraint equation, is minimized at every time step. The effectiveness of the proposed closed-open loop non-linear instantaneous optimal prediction control (CONIOPC) strategy is presented by the results of numerical simulations. Since non-linearity and time-delay effects are incorporated in the mathematical model throughout the derivation of the control methodology, good performance and stability of the controlled structural system are guaranteed. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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微种群遗传算法优化结构振动控制 总被引：5，自引：0，他引：5
本文将微种群遗传算法应用到结构振动控制中，用遗传算法优化控制器，以解决一类用经典线性反馈控制无法解决的半主动控制的优化问题，该方法提出将非线性控制问题线性化，导出了简化过程，然后利用遗传算法求解，它具有利用微种群遗传算法全局寻优，并且对目标函数的性态要求较少的特点，数值算例表明，本文方法是有效的。 相似文献
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A computational algorithm for maximizing the control efficiency in actively controlling the elastic structural responses during earthquake is proposed. Study of optimal linear control using a single degree of freedom shows that applying active control is very effective in reducing the structural displacement and velocity responses for long‐period structures, but at the same time it has an adverse effect in increasing the absolute acceleration response. The extent of this adverse effect reduces the effectiveness of the control system, and therefore it poses a limit on the maximum control force in order to provide maximum control efficiency. In view of this shortcoming, maximum control energy dissipation is used to define the most effective optimal linear control law. Less displacement and velocity response are expected as larger control force is applied, but there is always a limit that maximum control energy can be dissipated. This study shows that this limit depends on the structural characteristics as well as the input ground motion, and a general trend is that the maximum control energy decreases as damping increases. Finally, application of the proposed algorithm on a six‐storey hospital building is presented to show the effectiveness of using optimal linear control on a multi‐degree‐of‐freedom system from the control energy perspectives. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Trust-region based instantaneous optimal semi-active control of long-span spatially extended structures with MRF-04K damper 总被引：1，自引：0，他引：1
In the field of civil engineering, magnetorheological fluid （MRF） damper-based semi-active control systems have received considerable attention for use in protecting structures from natural hazards such as strong earthquakes and high winds. In this paper, the MRF damper-based semi-active control system is applied to a long-span spatially extended structure and its feasibility is discussed. Meanwhile, a _trust-region method based instantaneous optimal semi-active control algorithm （TIOC） is proposed to improve the performance of the semi-active control system in a multiple damper situation. The proposed TIOC describes the control process as a bounded constraint optimization problem, in which an optimal semi- active control force vector is solved by the trust-region method in every control step to minimize the structural responses. A numerical example of a railway station roof structure installed with MRF-04K dampers is presented. First, a modified Bouc- Wen model is utilized to describe the behavior of the selected MRF-04K damper. Then, two semi-active control systems, including the well-known clipped-optimal controller and the proposed TIOC controller, are considered. Based on the characteristics of the long-span spatially extended structure, the performance of the control system is evaluated under uniform earthquake excitation and travelling-wave excitation with different apparent velocities. The simulation results indicate that the MR fluid damper-based semi-active control systems have the potential to mitigate the responses of full-scale long-span spatially extended structures under earthquake hazards. The superiority of the proposed TIOC controller is demonstrated by comparing its control effectiveness with the clipped-optimal controller for several different cases. 相似文献
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A control method is presented for reducing the dynamic response of structures in the inelastic material range using a control force from an active bracing system. Recent full-scale experiments have verified the feasibility of implementing active control systems for control of seismic structures with existing technology. The proposed method of continuous pulse control uses closed-loop feedback control as a combination of two algorithms. The first is the instantaneous optimal algorithm which was derived assuming linear material behaviour, and the second is pulse control which applies a corrective pulse when a prespecified structural displacement, velocity, or acceleration threshold is exceeded. The three criteria of displacement, velocity, and acceleration lead to three pulse control schemes. Each of the three schemes is used in conjunction with the instantaneous optimal control to yield three continuous pulse algorithms, the displacement continuous pulse, velocity continuous pulse and acceleration continuous pulse. Comparisons between the three continuous pulse algorithms and the pulse control for seismic structures in the inelastic range show that the continuous pulse algorithms use less control energy and reduce the response better than pulse control. A comparison between the velocity continuous pulse and the non-linear optimal algorithm shows that the velocity continuous pulse uses a larger control force but is more adaptable than the non-linear optimal algorithm, in the sense that it can reduce the response of a given structure to various probable earthquakes. The non-linear optimal algorithm is more effective than the velocity continuous pulse for a single specific earthquake but is not as effective for other earthquakes which may occur in the life of the structure. 相似文献
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Considerable effort has been devoted to develop optimal control methods for reducing structural response under seismic forces. In this study analytical solution of the linear regulator problem applied widely to the control of earthquake‐excited structures is obtained by using the sufficient conditions of optimality even though almost all of the optimal controls proposed previously for structural control are based on the necessary conditions of optimality. Since the resulting optimal closed–open‐loop control cannot be implemented for civil structures exposed to earthquake forces, the solution of the optimal closed–open‐loop control is carried out approximately based on the prediction of the seismic acceleration values in the near future. Upon obtaining the relation between the exact optimal solution and future values of seismic accelerations, it is shown numerically that the solution of the optimal closed–open‐loop control problem can be performed approximately by using only the first few predicted seismic acceleration values if a given norm criteria is satisfied. Calculated performance measures indicate that the suggested approximate solution is better than the closed‐loop control and as we predict the future values of the excitation more accurately, it will approach the optimal solution. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献