基于卡尔曼滤波的振动台子结构试验方法研究

Application of Kalman filter in substructure shaking table test

振动台子结构试验是一种有效的实时结构混合试验方法,持续受到国内外学者的关注。利用振动台和其它加载装置进行联合加载,从而提升和扩展振动台的加载能力,实现大比例甚至足尺结构试验的目的。基于主动质量驱动器(AMD)加载方法的振动台子结构试验中,在试验子结构和数值子结构完全拆分的情况下,无论采用位移PID还是三参量控制,在界面加速度输入情况下AMD系统在3~5 min后会产生失稳现象,通过调整控制增益、对加速度反馈信号进行滤波无法消除这种现象。在加速度传感器噪声的影响下,子结构试验系统无法保持长期稳定,通过数值仿真表明现有的时滞补偿算法也无法消除这种失稳现象。考虑这种情况,将卡尔曼滤波引入界面加速度的量测环节,通过整体结构模型求得的界面加速度对实测界面加速度进行修正,从而提升了振动台子结构试验的系统稳定性和试验精度。数值仿真结果表明,通过设置合理的卡尔曼滤波参数,可以抑制加速度传感器随机噪声对子结构试验精度的影响,系统时滞稳定性也得到显著改善。文中的研究结果为振动台子结构试验的成功实施提供了一种可行的解决方案。

As an effective real-time hybrid simulation method,the substructure shaking table test attracts more and more attention of scholars all over the world.By loading with shaking table and other actuator devices,it improves and expands the loading capacity of shaking table,and realizes the purpose of large or even full-scale structure tests.In the substructure shaking table test loading based on the active mass driver(AMD)and shaking table,when the physical substructure and numerical substructure are completely split,no matter the displacement PID or three-variable control(TVC),the AMD system will instability after 3~5 min in the case of the interface acceleration input.This instability phenomenon can not be improved by adjusting the control gains or filtering the feedback signal of the interface acceleration.For the influence of sensor noise,the test system can not maintain long-term stability,and the numerical simulation shows that the conventional time-lag compensation algorithms can not improve the instability as well.To improve the stability and accuracy of the substructure shaking table test,Kalman filter was introduced into the measurement of the interface acceleration,and the measured interface acceleration was amended by the interface acceleration obtained from the full structure model.Numerical simulation shows that by turning the reasonable Kalman filter parameters,the influence of random sensor noise on test accuracy of the substructure can be suppressed,and the time-lag stability of the system can also be significantly improved.The works of this paper provided a feasible solution for the successful implementation of the substructure shaking table test.