Development of a Multifunctional Smart Board with Embedded Self-Sensing Piezoelectric Actuators

在对压电陶瓷自感知作动器约束铝板进行模态分析的基础上，建立了系统的状态方程。利用H_∞设计了控制器。和μ综合鲁棒控制理论，并对振动抑制进行了仿真和实验研究。结果表明，压电智能复合材料板的第一阶模态振动降低了15 dB。其次，建立了基于FIR滤波器和LMS自适应控制方法的压电智能复合材料板自感知振动控制系统。这种控制方法的优点是不需要振动系统的数学模型，即使系统参数发生变化，也能始终保持最优状态。采用该控制系统，不仅在第一阶模态的共振频率处，而且在1,200 Hz以下的所有模态的共振频率处都得到了成功的抑制。此外，采用自适应控制方法和智能板以及嵌入压电元件的自适应控制，构建了主动噪声控制系统。由于自感知压电致动器只能测量智能板的振动，一个估计器的压电元件的信号被构造来估计噪声压力水平。这种噪声控制系统的优点是它不需要麦克风，因此它可以在尺寸上更紧凑。实验结果表明，在1, 200 Hz以下的多个共振峰处，噪声都能得到有效抑制。

Based on the modal analysis of an aluminum plate bounded with piezoelectric elements that were used self-sensing actuators, the state equations of the system were established. A controller was designed using the H_∞. and μ synthesis robust control theory and both simulation and experiment of vibration suppression were carried. The results showed that the vibration of the first mode was reduced by 15 dB.Next a control system with self-sensing actuators and adaptive control approach, which is base on FIR filter and LMS was established for the vibration suppression of a smart composite board with embedded piezoelectric elements. The advantages of this kind of control are that it does not require the mathematical model of the vibration system and that it can always maintain the optimal state even when the parameters of the systems change. With the new control system, the vibration was successfully suppressed not only at the resonance frequency of the first mode, but also at the resonance frequency of all the modes under 1,200 Hz.Furthermore, an active noise control system was constructed using the adaptive control approach and the smart board and adaptive control with embedded piezoelectric elements. Since the self-sensing piezoelectric actuator can only measure the vibration of the smart board, an estimator was constructed to estimate the noise pressure level from the signals of the piezoelectric elements. The advantage of this noise control system is that it does need microphone so that it can be more compact in size. The experimental results show that the noise can be effectively suppressed at many resonance peaks under 1,200Hz.