关键词: 智能结构, 振动主动控制, 有限元法, &mu, 综合, 实验模态测试

Abstract:

Active vibration control of a smart flexible cantilever beam was studied by using mode theory and μ synthesis method. The actuator was piezoceramic patch, the sensor was strain gauge. The finite element method and experimental modal test were applied to obtain the dynamic model of the structure. Meanwhile, the results of comparative analysis of the two methods show there are errors between the finite element model and the actural system. Taking account into uncertainty of the external disturbance and measurement noises, and uncertainty of natural frequency, damping ratio and actuator parameters of the system, a μ synthesis approach was applied to design the vibration controller by selecting mode displacement as evaluation signal and selecting appropriate weighting function according to amplitude and frequency characteristics of the actual signals. First, the effectiveness of the controller was analyzed from a frequency domain point of view. The results show the controller can inhibit the impact of the uncertain disturbances on output strain, and can meet the control requirements in the case of uncertainty. Thus, the controller is robust. Second, the experiments on vibration control were performed. The experimental results show that the proposed controller can suppress the vibration response of the structure effectively.

Key words: smart structure;active vibration control;finite element method;&mu, synthesis;experimental modal test