带限位装置的基础滑移隔震结构的模糊滑模控制研究

FUZZY SLIDING MODE CONTROL OF SLIDING-ISOLATED BUILDINGS

滑移隔震体系的复位问题是其难以推广应用的一个突出障碍。基于模糊控制和滑模控制的优点,设计了一种由模糊控制律形成的滑模控制器,并将此控制器加入滑移隔震层中形成混合控制体系。同时,为了充分发挥滑移隔震层的被动控震作用和针对最大控制力可能受到限制时的情况,引入了饱和控制律。以一个八层基础滑移隔震结构模型为例,完成了相应的算例数值分析。算例数值分析结果表明,所提出的这种混合控制方法控制效果明显,不仅能有效地减小上部结构的地震峰值响应,而且能有效地减小基础滑移隔震层的滑移量,使隔震体系具有较好的复位功能;同时由于引入模糊控制律,使得在不降低系统鲁棒性的前提下,达到了削弱控制系统抖振的目的。

Based on the theories of sliding mode control and fuzzy control, a new sliding mode control method is presented for application in seismically-excited buildings with a frictional-type sliding-isolation system. The dynamic behavior of buildings equipped with a base-sliding-isolation system is highly nonlinear, and the new sliding mode control method involving fuzzy adaptive reaching law is ideal for such nonlinear systems. The undue chattering effect, which is the major disadvantage of conventional sliding mode controllers, is avoided by introducing the new sliding mode control method. Moreover, here the saturated control law is designed for us to use when the control force exceeds the maximum control force of an actuator. Finally, numerical simulations for an eight-story building model equipped with a frictional-type sliding-isolation system are given. Simulation results show preliminarily that: (1) the sliding mode control method is robust with respect to parametric uncertainties of the structure; (2) the sliding mode control method can keep the chattering effect sufficiently low so as to ensure the system stable; and (3) the hybrid control method is more effective for reducing the building response under strong earthquakes than an active or passive control method used alone.