Active Control of Structure Instrumented with Optical Fiber Sensors Under Earthquake Loading

本项目试图研究主动控制中的以下关键问题：1)标准最优控制技术需要了解结构响应的整个时程，通过求解Riccati方程来计算所需的控制力。同时，提出了用于在线控制的瞬时最优控制算法。缺乏证明其全局意义上的收敛性和可控性的解析论证；2)控制力与位移成正比假设的有效性；结构在地震荷载作用下的速度和加速度。当且仅当在通过最小化目标函数来确定控制力时忽略对结构的激励力时，这个假设是可以接受的。​为了回答上述问题，本课题研究了两种控制方案：极点放置控制器和神经网络控制器。这两种方案将进行分析和实验研究。此外，光纤传感器将被应用于比例模型结构。通过光纤传感器与经典传感器测试信号的比较，对用于土木工程结构的传感器系统提出改进建议。总体而言，本项目将通过以下三个主要研究任务进行：(1)控制方法；(2)振动台比例结构模型试验；(3)传感器系统的改进。

This project attempts to study the following key problems in active control: 1) the standard optimal control technique requires the knowledge of the entire time history of the structural response to compute the necessary control force by solving the Riccati equation. In the mean time, instantaneous optimal control algorithm was developed for on-line control. It lacks the analytical argument to prove its convergence and controllability in the global sense, and 2) the validity of the assumption that the control force is proportional to the displacement, velocity and acceleration of the structure subjected to earthquake loading. This assumption is acceptable if and only if the excitation force to the structure is ignored in the determination of the control force from minimizing the objective function. To answer the above questions, two types of control schemes are studied in this project: the pole placement controller and the neural network controller. These two schemes will be investigated both analytically and experimentally. In addition, optical fiber sensors will be applied to the scaled model structures. Through comparison of test signals between the optical fiber sensors and classical sensors, suggestions for improvements of the sensor system for use in civil engineering structures will be made possible. Overall, this project will be undertaken through the following three major research tasks: (1) control methodology; (2) scaled structural model experimental test on shake table; and (3) improvement of sensor systems.