空间结构耦合模态控制及实验研究

智能结构以主动元件为传感器和驱动器,根据结构的动态响应和控制要求,自适应地改变结构的动态性能,实现结构特性的自调节功能,以增强结构适应于外界环境变化的能力.结构振动主动控制方法中常用的模态空间控制方法,就是将系统方程转化到模态坐标下,从而得到内部解耦的以模态坐标表示的方程组,然后根据一定的控制方法,计算出模态控制力,实现实时控制.该方法计算简单,效率高,能满足实时控制的需要.本文根据一个三层智能结构主动控制实验,介绍了耦合模态控制理论及实现方法,设计并阐述了压电主元杆件的工作原理,根据Riccati方程得到了主元杆件的最优布置.通过对实验数据运用五点滑动平均平滑法进行处理分析及频谱分析可以看到,智能结构通过主动控制,对相应的控制模态位移及加速度有很大的抑制作用,对应的模态阻尼系数得到了不同程度的提高.

Coupling Mode Control and Experimental Study of a Space Structure

Intelligence structures take active components as sensor and actuator, therefore achieve self-adjusting to enhance structure adaptability to external environment change according to the structure dynamic response and control requirements and dynamic performance self-adaptive change. Mode space control is a common used method in active control of space structure vibration. In this method, the system equation is firstly transferred to modal coordinates, secondly, the internal decoupling equations expressed by modal coordinates are obtained; next, the modal control force was calculated by certain control methods and the real-time control finally realized. This method is simple, high effective and practical for real-time control. Based on experiment of an active control of a three-story intelligence structure, this paper introduces the coupling modal control theory and relevant implementation methods. The working principle and design of the piezoelectric driving lever are expounded, the optimum layout is determined based on Riccati equation. Experimental data processing by using five-point moving average smoothing method and frequency spectrum analyse show that through active control, the intelligence structures can produce greatly restraining effects on corresponding control modal displacement and acceleration; meanwhile the corresponding modal damping coefficient is improved in different degrees.