Wavelet-Based Algorithms for Control of Smart Civil Structures - Phase Two Study

主要研究者：Hojjat Adeli，俄亥俄州这是两部分研究工作的第二阶段，旨在研究小波作为土木结构控制的一种手段。技术工作与作为第1阶段工作一部分确定的工作范围相结合。 虽然经典的反馈控制算法，如线性二次调节器（LQR）和线性二次高斯（LQG）算法可以用来减少振动，但它们有许多基本的缺点。它们在结构的固有频率附近实现了显著的衰减水平，但是当外部干扰的频率与结构的固有频率甚至稍微不同时，它们不能抑制振动。经典最优控制算法的一个局限性是由于输入激励必须是先验已知的，而对于承受地震或风荷载的土木结构来说，情况并非如此。 智力优势：提出的研究的主要目标是探索基于小波的算法，以创建一个新的控制模型，主动，半主动和混合控制的土木结构受到动态力，如地震和风，克服现有的反馈控制算法的一些缺点。新的控制模型将a）具有在输入频率范围内抑制振动的能力，B）不太容易受到结构建模近似和误差的影响，以及c）包括外部激励项。 这是通过巧妙地集成反馈控制算法，如LQR或LQG算法，滤波x最小均方（LMS）算法和小波。目标是在外部动态干扰下实现真实的实时最优控制。建议的研究重点将是利用小波和基于小波的算法的滤波和变换特性的最优控制策略的发展。 所提出的研究的第二个目标是探索一个混合控制系统的发展，通过明智的集成的被动补充阻尼系统与半主动调谐液柱阻尼器（TLCD）系统。新模型利用了被动和半主动控制系统的优点，从而提高了控制系统在正常操作以及电源或计算机故障期间的整体性能、可靠性和可操作性。鲁棒小波混合反馈LMS控制算法将被用来找到最佳值的控制参数。所提出的混合控制系统消除了对大功率需求的需要，不像其他提出的混合控制系统，其中主动和被动系统相结合。 更广泛的影响：拟议的研究对整个社会的潜在好处将是创造新一代智能土木结构，提高安全性和可靠性，以应对该国大部分地区遇到的地震和强风等自然灾害。拟议的研究将a）导致新的控制技术，减轻灾害的结构受到动态地震和风荷载，B）是有价值的振动控制的一般领域，包括控制的机械和航空航天结构，和c）导致在使用小波的解决方案的其他智能民用基础设施系统的新见解。

PI: Hojjat Adeli, Ohio StateThis is the second phase of a two-part research effort aimed at examining wavelets as a means of control for civil structures. The technical effort is integrated with the scope of work identified as part of the phase 1 effort. Project Summary Even though classical feedback control algorithms such as the Linear Quadratic Regulator (LQR) and Linear Quadratic Gaussian (LQG) algorithms can be used to reduce vibrations, they suffer from a number of fundamental shortcomings. They achieve a significant level of attenuation in the vicinity of the natural frequencies of the structure, but fail to suppress the vibrations when frequency of the external disturbance differs even slightly from the natural frequencies of the structure. A limitation of classical optimal control algorithms is due to the fact that the input excitation must be known a priori which is not the case for civil structures subjected to earthquake or wind loading. Intellectual Merits: The primary objective of the proposed research is to explore wavelet- based algorithms for creation of a new control model for active, semi-active, and hybrid control of civil structures subjected to dynamic forces such as earthquakes and winds overcoming some of the shortcomings of the existing feedback control algorithms. The new control model will a) have the ability to suppress vibrations over a range of input frequencies, b) be less susceptible to structural modeling approximations and errors, and c) include the external excitation term. This is achieved through adroit integration of a feedback control algorithm such as the LQR or LQG algorithm, the filtered-x Least Mean Square (LMS) algorithm, and wavelets. The goal is to achieve optimum control under external dynamic disturbances in real time. A focus of the proposed research will be development of optimal control strategies utilizing the filtering and transformation characteristics of wavelets and wavelet-based algorithms. A secondary objective of the proposed research is to explore the development of a hybrid control system through judicious integration of a passive supplementary damping system with a semi-active tuned liquid column damper (TLCD) system. The new model utilizes the advantages of both passive and semi-active control systems, thereby improving the overall performance, reliability, and operability of the control system during normal operations as well as a power or computer failure. The robust wavelet-hybrid feedback LMS control algorithm will be used to find optimal values of the control parameters. The proposed hybrid control system eliminates the need for a large power requirement, unlike other proposed hybrid control systems where active and passive systems are combined. Broader Impacts:The potential benefits of the proposed research to society at large will be creation of a new generation of smart civil structures with improved safety and reliability against natural hazards such as earthquakes and strong winds encountered in most of the country. The proposed research will a) lead to new control techniques for hazard mitigation of structures subjected to dynamic seismic and wind loading, b) be of value to the general domain of vibration control including control of mechanical and aerospace structures, and c) result in new insights in the use of wavelets for solution of other intelligent civil infrastructure systems.