随机振动功率谱的H_∞双自由度跟踪控制研究  

Tracking control of power spectrum density of stochastic vibration by two degrees of freedom H∞ controller

作　　者：游伟倩[1,2] 陈怀海[1,2] 贺旭东[1,2] 崔旭利[1,2] 

机构地区：[1]飞行器结构力学与控制教育部重点实验室,江苏南京210016 [2]南京航空航天大学振动工程研究所,江苏南京210016

出　　处：《振动工程学报》2010年第3期317-323,共7页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(10972104);江苏省研究生科研创新计划资助项目(CX07B-062z)

摘　　要：在不考虑互谱的情况下,提出了一种双振动台随机振动控制试验的H∞双自由度控制新方法,能够快速平稳地使控制谱得到收敛,并满足参考谱的要求。研究了基于Η∞控制理论的双振动台解耦控制方法,应用Η∞双自由度控制方法进行双振动台随机振动控制。首先,对于原高阶模型系统进行模型降阶处理,针对降阶系统进行回路整形设计。其次,根据截去振动系统高阶模态的降阶P系统设计Η∞控制器,引入了模型的不确定性扰动。最后,用一悬臂梁模型进行数值仿真验证,仿真结果表明在20~2 000 H z频率范围内,利用Η∞双自由度控制方法设计的控制器,能使输出控制谱与设定参考谱的自谱密度误差控制在±1 dB以内,完全符合双振动台设计的控制要求。A new approach is presented for random vibration test of dual-shaker using H∞ based optimal decoupling method with two degrees-of-freedom controller without taking the cross-spectra into account.The algorithm can make the control spectrum converge to the reference spectrum quickly and stably.Firstly,the original high-order stable system model is reduced to a low-order one which is shaped by the H∞ loop-shaping design method.Then a controller is designed based on the reduced model using the H∞ two degrees of freedom control method which introduced model uncertainties into the system.Lastly,a cantilever beam was used to test the proposed control approach.A two-inputstwo outputs control model was set up based on the beam.The results demonstrated that,in the frequency range from 20 to 2000 Hz,the controller could make the error between the output PSD and the reference one less than ±1 dB,which is perfect for the random vibration control test of dual-shaker.

关 键 词：Η∞控制 振动控制 随机振动 双振动台 解耦 

分 类 号：O324[理学—一般力学与力学基础] TB535[理学—力学]