Investigation into Time Delays and Noncollocation in Structural Control

9424501乌德瓦迪该项目将进行理论和实验研究，以调查时间延迟对强震地面震动下结构系统控制的影响。同时考虑并置和非并置控制配置。将制定一般控制方法和指导方针。当执行器和传感器配置在一起时，在存在时滞的情况下，对于(A)无阻尼项、(B)经典阻尼项和(C)非经典阻尼项的结构系统，可以找到小增益为零的稳定性条件。利用导致配置反馈控制不稳定的时滞，实现非配置反馈控制系统的无穷小增益稳定性。所有的分析结果都将应用于一个简单的五自由度系统进行数值验证。这一研究将有助于理解反馈回路中不可避免的小时滞对闭环系统稳定性的影响。研究结果将直接应用于动态环境中各种结构和机械系统的鲁棒控制，特别是在抑制地震地面振动方面。***

9424501 Udwadi This project will conduct theoretical and experimental studies to investigate the effects of time delays on the control of structural systems subjected to strong earthquake ground shaking. Both collocated as well as noncollocated control configurations will be considered. A general control methodology and guide lines will be developed. Stability conditions for vanishingly small gains, in the presence of time delays, when actuator and sensor are collocated, will be found for (a)undamped, (b) classically damped, and (c)nonclassically damned structural systems. The time delays which cause instability for collocated feedback control will be utilized to achieve infinitesimal gains stability for noncollocated feedback control systems. All analytical results will be applied to a simple five degree-of-freedom system for numerical verifications. This study will help understand the effects of small time delays, which are inevitable in the feedback loop, on the stability of the closed loop control systems. The results will have immediate and direct application to the robust control of a wide variety of structural and mechanical systems in dynamic environments, especially in the suppression of vibrations generated by earthquake ground shaking. ***