基于模糊控制的柔性耦合梁压电主动抑振研究

Study on piezoelectric active vibration control of piezoelectricflexible coupled beams based on fuzzy control

弯曲振动是影响柔性梁工作性能和稳定性的重要因素,而压电主动控制是实现柔性梁抑振的途径之一.为了提高压电主动控制系统的抑振效果,利用LabVIEW平台设计了基于模糊控制的柔性耦合梁压电主动抑振系统.根据耦合梁动力学理论,建立了压电柔性耦合梁的动力学模型,求解了柔性梁的耦合固有频率并分析其模态特性.根据模态振型,为了实现最佳抑振效果,将MFC压电片设置在振幅最大位置处,并以此设计压电振动控制系统.此外,利用LabVIEW平台和NI数据采集卡搭建了振动控制测试系统,对不同激励下柔性梁振动的抑振效果进行测试和比较.结果表明:当柔性梁的振动频率低于一阶固有频率时,梁末端处的振动位移最大.将MFC压电片设置在柔性梁末端,在连续激励振动下,通过模糊控制可以使柔性梁的振动幅值减小35%,且模糊控制的减振效果优于PID控制.

Bending vibration is an important factor affecting the performance and stability of flexible beams,and piezoelectric active control is one of the ways to achieve vibration suppression of flexible beams.In order to improve the vibration suppression effect of piezoelectric active control systems,a piezoelectric active vibration control system of a flexible coupled beam based on fuzzy control was designed using LabVIEW platform.According to the dynamic theory of coupled beams,the dynamic model of a piezoelectric coupled flexible beam was established,the coupling natural frequency of the flexible beam was solved,and its modal characteristics were analyzed.According to the modal shape,in order to achieve the best vibration suppression effect,the MFC piezoelectric plate is set at the position of the maximum amplitude,and the piezoelectric vibration control system is designed accordingly.Besides,the vibration control test system was built by LabVIEW platform and NI data acquisition card,and the vibration suppression effects of flexible beams under different excitation were tested and compared.The results show that when the vibration frequency of the flexible beam is lower than the first-order natural frequency,the vibration displacement is the largest at the end of the beam.When an MFC piezoelectric plate is set at the end of flexible beam,the vibration amplitude of the flexible beam can be reduced by 35%by fuzzy control under continuous excitation,and the vibration reduction effect of fuzzy control is better than that of PID control.